KR102846362B1 - Position measurement unit and electric actuator - Google Patents

Abstract

The present invention relates to a position measuring unit and an electric actuator.
According to one aspect of the present invention, a position measuring unit and an electric actuator are disclosed, which measure the driving position of an electric actuator configured to transmit the rotational force of a motor shaft to a valve drive shaft through a power transmission mechanism, and enable mechanical position measurement through an indicator unit connected to a transmission gear train, and enable easy device setting in consideration of the rotational speed of the electric actuator by variably fixing the forward and backward position of a gear adjustment gear included in the transmission gear train so as to adjust the gear ratio of the input rotational force.

Description

Position measurement unit and electric actuator

The present invention relates to a position measuring unit and an electric actuator, and more particularly, to a position measuring unit and an electric actuator configured to measure the driving position of an electric actuator configured to transmit the rotational force of a motor shaft to a valve drive shaft through a power transmission mechanism, wherein mechanical position measurement is possible through an indicator unit connected to a transmission gear train, and the forward/reverse direction position of a gear adjustment gear included in the transmission gear train is variably fixed so as to adjust the transmission ratio of the input rotational force, thereby enabling easy device setting in consideration of the rotational speed of the electric actuator.

Electric actuators are used to rotary control passive elements such as valves. For example, electric actuators are configured to transmit the rotational force of a motor shaft to a valve drive shaft through a gear mechanism.

Typically, electric actuators are equipped with either an indicator that mechanically measures and displays the driving position, or an encoder that electronically measures and displays the driving position through a control unit.

As an example of prior art, the applicant of the present invention, Republic of Korea Patent No. 10-1868328 (June 11, 2018), proposed a three-phase vector control multi-turn actuator with a built-in rotary encoder, which is convenient to use by incorporating a rotary encoder into the rotational shaft of the drive motor, and enables precise control by installing a board that performs three-phase vector control inside the valve drive unit.

However, in the case of an electric actuator that mechanically measures and displays the driving position using an indicator, a gear train of various configurations is installed between the driving shaft driven by the motor and the indicator to transmit the rotational force, and there was an inconvenience in setting the display position of the indicator according to the rotation conditions of the electric actuator.

For example, when the maximum rotation number of the output gear of the gear train required for the indicator to rotate 270 degrees to display "OPEN" and "CLOSE" is 100 rotations, if the output gear rotates 150 and 200 times, the indicator will rotate more than 360 degrees. However, since the position of the indicator rotating multiple times cannot be accurately determined in the field, there was an inconvenience in that additional time may be required to prepare an additional transmission gear to change the transmission ratio of the gear train for setting the rotation number.

Republic of Korea Patent No. 10-1868328 (June 11, 2018) Republic of Korea Patent No. 10-1452364 (October 13, 2014) Republic of Korea Patent No. 10-1239384 (February 26, 2013)

The present invention has been devised in consideration of the above-described problems, and the purpose of the present invention is to provide a position measuring unit and an electric actuator configured to measure the driving position of an electric actuator configured to transmit the rotational force of a motor shaft to a valve drive shaft through a power transmission mechanism, and to enable mechanical position measurement through an indicator unit connected to a transmission gear train, and to enable easy device setting in consideration of the rotational speed of the electric actuator by variably fixing the forward and backward position of a gear adjustment gear included in the transmission gear train so as to adjust the gear ratio of the input rotational force.

According to one aspect of the present invention for achieving the above object, there is provided a transmission gear train comprising: at least one first transmission gear rotatably installed in a first transmission gear shaft; at least one second transmission gear rotatably installed in a second transmission gear shaft arranged parallel to the first transmission gear shaft and meshed with the first transmission gear; a shift adjustment gear rotatably installed in a third transmission gear shaft arranged parallel to the first transmission gear shaft and having a variably fixed forward/rearward position, meshing with one of the at least one first transmission gear and the at least one second transmission gear according to the variably fixed forward/rearward position, and receiving a rotational force input based on the first transmission gear by shifting it at a gear ratio determined according to an engagement position; and a shift output gear integrally installed in a axial connection with the third transmission gear shaft and rotating together therewith. A position measurement unit is disclosed, which comprises an indicator unit having a position input gear that receives rotational force shifted from the shift output gear side and is coupled to one end of a gear shaft arranged parallel to the third transmission gear shaft, and an indicator unit that displays a mechanical position measurement result is installed on the other end.

According to another aspect of the present invention, a position measuring unit is disclosed, comprising: a transmission gear train in which at least one transmission gear is respectively installed based on two parallelly arranged transmission gear shafts, a transmission adjustment gear whose front-rear position can be variably fixed and a transmission output gear that outputs rotational force are installed based on another transmission gear shaft that is arranged parallel to the two transmission gear shafts, a rotational force is input based on one of the transmission gears, the transmission adjustment gear meshes with one of the transmission gears, and the input rotational force is shifted at a transmission ratio determined according to the engagement position of the transmission adjustment gear and outputted through the transmission output gear; and an indicator unit in which a position input gear that receives the shifted rotational force from the transmission output gear side is shaft-coupled to one end of a gear shaft arranged parallel to the other one transmission gear shaft, and an indicator that displays a mechanical position measuring result is installed on the other end.

According to another aspect of the present invention, an electric actuator including the position measuring unit is disclosed, wherein the rotational force of the motor shaft is transmitted to a worm shaft having a worm installed through a power transmission mechanism, the rotational force of the worm is transmitted to the valve driving shaft through a worm wheel installed coaxially to the valve driving shaft, and the motor shaft, the worm shaft, and the valve driving shaft are rotatably supported based on a casing, and the position measuring unit receives the rotational force through a transmission gear train that receives the rotational force from a ring gear installed coaxially to the valve driving shaft.

The present invention measures the driving position of an electric actuator configured to transmit the rotational force of a motor shaft to a valve drive shaft through a power transmission mechanism, and enables mechanical position measurement through an indicator unit connected to a transmission gear train, and adjusts the transmission ratio of the input rotational force by variably fixing the forward and backward position of a gear adjustment gear included in the transmission gear train, thereby enabling easy device setting considering the rotational speed of the electric actuator.

Figure 1 is a perspective view of an electric actuator according to an embodiment of the present invention;
Figure 2 is a perspective view showing the main components of an electric actuator according to an embodiment of the present invention;
Figure 3 is a perspective view of a position measuring unit according to an embodiment of the present invention;
Figure 4 is a side view showing the main components of a position measuring unit according to an embodiment of the present invention;
FIG. 5 is a cross-sectional side view showing the main components of a position measuring unit according to an embodiment of the present invention;
Figure 6 is a perspective view showing the main components of the transmission gear train and indicator unit according to an embodiment of the present invention.
Figures 7 and 8 are plan views showing the main components of the transmission gear train and indicator unit according to an embodiment of the present invention.
Figure 9 is a perspective view of an encoder unit according to an embodiment of the present invention;
Fig. 10 is a cross-sectional perspective view of an encoder unit according to an embodiment of the present invention in another direction;
Fig. 11 is a side cross-sectional view of an encoder unit according to an embodiment of the present invention;
Fig. 12 is a perspective view of a rotating disk of an encoder unit according to an embodiment of the present invention;
FIGS. 13 and 14 are perspective views showing the main components of a transmission gear train and an indicator section according to another embodiment of the present invention.

The present invention may be embodied in various forms without departing from its technical spirit or essential characteristics. Therefore, the embodiments of the present invention are merely illustrative in all respects and should not be construed as limiting.

Terms such as "first" and "second" are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component."

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected or connected to that other component, but there may also be other components in between.

The singular expressions used in this application include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "include," "have," and "have" are intended to indicate the presence of components or combinations thereof described in the specification, but do not preclude the possibility of other components or features being present or added.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

FIG. 1 is a perspective view of an electric actuator according to an embodiment of the present invention, and FIG. 2 is a perspective view showing main components of an electric actuator according to an embodiment of the present invention.

The electric actuator (A) of this embodiment uses the driving force of the motor (10) to rotary control a passive element such as a valve (not shown).

Referring to FIG. 1, the electric actuator (A) of the present embodiment includes, as main components, a motor (10) that provides driving force, a control unit (50) that controls the driving of the motor (10) by an input control command and a preset control logic, a terminal (60) that is connected to the control unit (50) and transmits and receives control/measurement signals with the outside (e.g., a control panel), a manual handle (70) that enables manual operation when necessary, and an indicator unit (500) that displays the mechanical position measurement result for the valve drive shaft (32). The indicator unit (500) indicates whether the rotational drive position of the electric actuator (A) is the "OPEN" or "CLOSE" position. For example, the electric actuator (A) of the present embodiment may be a multi-turn type electric actuator (A) that is capable of rotationally driving the valve drive shaft (32) at a rotation angle greater than 360 degrees. Since the multi-turn type electric actuator (A) is driven to rotate at a rotation angle greater than 360 degrees, measurement of the absolute rotation angle for a rotation number greater than 1 rotation is required for rotation control.

Preferably, the electric actuator (A) of the present embodiment may include an encoder unit (200) to further perform electronic position measurement together with mechanical position measurement. In this case, the control unit (50) may recognize the absolute rotational position of the valve drive shaft (32) in real time using the electronic position measurement signal provided from the encoder unit (200) based on a preset control logic and use this as feedback information for driving control of the motor (10). In addition, the control unit (50) may include a display that displays information regarding control input/output, and may also display the recognized absolute rotational position of the valve drive shaft (32) through the display.

Referring to FIG. 2, the electric actuator (A) of the present embodiment transmits the rotational force of the motor shaft (12) generated by the driving of the motor (10) to the worm shaft (22) on which the worm (20) is installed through the power transmission mechanism (14), and transmits the rotational force of the worm (20) to the valve drive shaft (32) through the worm wheel (30) installed coaxially to the valve drive shaft (32). A rotational shaft (e.g., a valve shaft) of a driven element such as a valve (not shown) is coupled and installed at the lower end of the valve drive shaft (32). Various known gear mechanisms, shaft transmission mechanisms, etc. can be applied to the power transmission mechanism (14). The motor shaft (12), the worm shaft (22), and the valve drive shaft (32) are supported to be rotatable using bearings (not shown) based on the casing (2).

The input gear (100) of the position measuring unit (PU) is configured to receive rotational force through a transmission gear train (36) that receives rotational force from a ring gear (34) installed coaxially on the valve drive shaft (32). The number of rotations of the input gear (100) can be preset according to the rotational speed of the valve drive shaft (32). The transmission gear train (36) can be configured in various ways according to the detailed configuration of the electric actuator (A). Reference numeral 36a denotes a gear of the transmission gear train (36) that meshes with the input gear (100) to transmit rotational force.

The control unit (50) drives the motor (10) to rotate in the forward or reverse direction by the input control command and preset control logic, and accordingly, the valve drive shaft (32) rotates in the forward or reverse direction to open or close the valve, and the position measuring unit (PU) measures or displays the driving position of the valve drive shaft (32) in real time.

The position measuring unit (PU) of the present embodiment can mechanically measure the position and visually display the driving position of the valve drive shaft (32) using the transmission gear train (400) and the indicator unit (500). In addition, when the position measuring unit (PU) of the present embodiment includes an encoder unit (200), an electronic position measuring signal of the valve drive shaft (32) is generated using the encoder unit (200) and provided to the control unit (50). The control unit (50) recognizes the absolute rotational position of the valve drive shaft (32) in real time based on the electronic position measuring signal provided from the encoder unit (200), and can use this to perform forward/reverse rotation control to rotate the motor (10) to the open position/close position according to a control command (e.g., open/close), or perform stop control upon reaching the open position/close position.

FIG. 3 is a perspective view of a position measuring unit according to an embodiment of the present invention, FIG. 4 is a side view showing main components of a position measuring unit according to an embodiment of the present invention, FIG. 5 is a side sectional view showing main components of a position measuring unit according to an embodiment of the present invention, FIG. 6 is a perspective view showing main components of a transmission gear train and an indicator unit according to an embodiment of the present invention, FIGS. 7 and 8 are plan views showing main components of a transmission gear train and an indicator unit according to an embodiment of the present invention, FIG. 9 is a perspective view of an encoder unit according to an embodiment of the present invention, FIG. 10 is a cross-sectional perspective view of an encoder unit according to an embodiment of the present invention from another direction, FIG. 11 is a side sectional view of an encoder unit according to an embodiment of the present invention, and FIG. 12 is a perspective view of a rotating disk of an encoder unit according to an embodiment of the present invention.

In the above drawings, for convenience of explanation, the symbol F represents the front direction, and the symbol R represents the rear direction. The front direction (F) represents the input gear (100) side, which is the input side of the position measuring unit (PU), and the rear direction (R) represents the indicator unit (500) side, which is the opposite side. In addition, the symbol FR represents a frame for installing each element, and in some drawings, for convenience of explanation, some of the frames (FR) are deleted and only major components are shown.

The position measurement unit (PU) of this embodiment is configured to include an input gear (100), an encoder unit (200), an output gear (300), a transmission gear train (400), and an indicator unit (500), and is capable of mechanical position measurement, and also electronic position measurement.

The above input gear (100) is axially coupled to one end of the first gear shaft (101) and receives rotational force. For example, the input gear (100) may be configured in the form of a known spur gear or helical gear, but is not limited thereto. Unless otherwise specified, other gears below may also be configured in a similar form.

The encoder unit (200) includes a plurality of rotating disks (210) that are axially coupled to the first gear shaft (101) and spaced apart from each other in parallel and each having a pattern slit (211) that forms a concentric track, a plurality of idle gears (220) that are axially coupled to the second gear shaft (201) that is arranged parallel to the first gear shaft (101) and transmit rotational force between the plurality of rotating disks (210), a light-emitting unit (230) that projects LED light (L) to pass through the pattern slit (211) of the rotating disk (210), and a light-receiving unit (240) that receives the LED light (L) that has passed through the pattern slit (211), thereby generating an electronic position measurement signal. The generated electronic position measurement signal is input to the control unit (50).

The first gear shaft (101) and the second gear shaft (201) are supported in a rotatable manner based on a frame (FR). The frame (FR) is installed inside the casing (2) and its structure can be modified to support the gear and the gear shaft.

The above output gear (300) is coupled to the other end of the first gear shaft (101) and outputs rotational force.

The above-mentioned transmission gear train (400) has transmission gears (410, 420) installed based on one or more transmission gear shafts (401, 402) arranged parallel to the first gear shaft (101), receives rotational power from the output gear (300), and outputs the converted rotational power through the transmission output gear (440).

More specifically, the above-described transmission gear train (400) has one or more transmission gears (410, 420) installed on each of two transmission gear shafts (401, 402) arranged in parallel, and a transmission adjustment gear (430) whose forward/reverse position can be variably fixed and a transmission output gear (440) that outputs rotational force are installed on another transmission gear shaft (403) arranged in parallel with the two transmission gear shafts (401, 402).

In addition, the transmission gear train (400) is configured to input rotational force based on one of the transmission gears (410), mesh with one of the transmission gears (410 or 420) and the shift adjustment gear (430), and output the input rotational force through the shift output gear (440) by shifting the gear ratio determined according to the engagement position of the shift adjustment gear (430).

The above indicator unit (500) is configured such that a position input gear (510) that receives a rotational force shifted from the shift output gear (440) is coupled to one end of a third gear shaft (501) arranged parallel to the transmission gear shafts (401, 402), and an indicator (520) that displays a mechanical position measurement result is installed on the other end. A power transmission gear train (492) may be provided between the shift output gear (440) and the position input gear (510).

For example, the indicator (520) is configured in the form of a circular disk and is coupled to the end of the third gear shaft (501) so that it can be visually confirmed which rotational position it is in, between “OPEN” and “CLOSE,” depending on the rotational position of the third gear shaft (501).

The above-mentioned transmission gear train (400) and indicator unit (500) will be described in more detail.

The above-described transmission gear train (400) includes a first transmission gear shaft (401), a first transmission gear (410), a second transmission gear shaft (402), and a second transmission gear (420). The first transmission gear shaft (401) and the second transmission gear shaft (402) are supported based on a frame (FR).

The above first transmission gear shaft (401) is arranged parallel to the above first gear shaft (101).

The first transmission gear (410) is rotatably installed on the first transmission gear shaft (401) and is coupled to the first transmission input gear (411) and the first transmission output gear (412) which have different sizes and each have a number of teeth according to a preset gear ratio along the outer periphery and are integrally connected. For example, the first transmission input gear (411) may have a larger diameter and a larger number of teeth than the first transmission output gear (412), and as a result, when the rotation input to the first transmission input gear (411) is output to the first transmission output gear (412), a deceleration output may be achieved.

The above second transmission gear shaft (402) is arranged parallel to the first gear shaft (101) and is installed spaced apart from the first transmission gear shaft (401).

The second transmission gear (420) is rotatably installed on the second transmission gear shaft (402) and is coupled to the second transmission input gear (421) and the second transmission output gear (422), which each have a number of teeth according to a preset gear ratio along the outer periphery and have different sizes, are integrally connected. For example, the second transmission input gear (421) may have a larger diameter and a larger number of teeth than the second transmission output gear (422), and as a result, when the rotation input to the second transmission input gear (421) is output to the second transmission output gear (422), a deceleration output may be achieved.

For example, the first gear input gear (411) and the second gear input gear (421) may have the same number of teeth, and the first gear output gear (412) and the second gear output gear (422) may also have the same number of teeth, but are not limited thereto.

One or more first transmission gears (410) are installed on the first transmission gear shaft (401).

One or more second transmission gears (420) are installed on the second transmission gear shaft (402).

The first transmission gear (410) rotates by receiving rotational force from the output gear (300) through the first transmission input gear (411).

The second transmission gear (420) rotates by receiving rotational force from the first transmission output gear (412) through the second transmission input gear (421).

The rotational power is output through the transmission output gear (440) based on the rotation of either the first transmission gear (410) or the second transmission gear (420).

As a more preferable example, a plurality of transmission gears (410, 420) may be installed on each of the first transmission gear shaft (401) and the second transmission gear shaft (402).

For example, two or more first transmission gears (410-1 to 410-5) are installed on the first transmission gear shaft (401), and two or more second transmission gears (420-1 to 420-5) are installed on the second transmission gear shaft (402).

At least one (e.g., 410-2) of the two or more first transmission gears (410-1 to 410-5) receives rotational power from the second transmission output gear (412) of one (e.g., 420-1) of the two or more second transmission gears (420-1 to 420-5) through the first transmission input gear (411) and rotates. In this process, a reduced rotation is achieved.

For example, in the above transmission gear train (400), the first transmission input gear (411) of the first transmission gear 410-1 rotates by receiving rotational force from the output gear (300), the second transmission input gear (411) of the second transmission gear 420-1 rotates by receiving rotational force from the first transmission output gear (412) of the first transmission gear 410-1, the first transmission input gear (411) of the first transmission gear 410-2 rotates by receiving rotational force from the second transmission output gear (412) of the second transmission gear 420-1, and the second transmission input gear (411) of the second transmission gear 420-2 rotates by receiving rotational force from the first transmission output gear (412) of the first transmission gear 410-2, so that the transmission ratio (reduction ratio) increases as it goes from the front transmission gear to the rear transmission gear. It provides the function of a transmission (reducer).

The ratio of the number of teeth based on the output/input of each of the first transmission gears (410-1 to 410-5) and the ratio of the number of teeth based on the output/input of each of the second transmission gears (420-1 to 420-5) can be changed according to the design specifications.

The above-mentioned transmission gear train (400) includes a third transmission gear shaft (403), a transmission adjustment gear (430), and a transmission output gear (440). The third transmission gear shaft (403) is supported in a rotatably manner based on a frame (FR).

The above third gear shaft (403) is arranged parallel to the above first gear shaft (101).

The above-mentioned transmission output gear (440) is integrally installed and shaft-coupled to the third transmission gear shaft (403) and rotates together.

The above-mentioned transmission adjustment gear (430) is installed in a shaft-joint manner on the third transmission gear shaft (403) and has a variable and fixed front-rear position. Depending on the variable and fixed front-rear position, it meshes with one of the one or more first transmission gears (410) and one or more second transmission gears (420), and receives the input rotational force based on the first transmission gear (410) by changing it at a transmission ratio determined according to the meshing position.

For example, the above-described gear adjustment gear (430) rotates by receiving rotational force from the first gear output gear (412) of one of the first gears (410), or rotates by receiving rotational force from the second gear output gear (422) of the second gear (420).

As described above, the first transmission gear (410-1 to 410-5) and the second transmission gear (420-1 to 420-5) provide the function of a transmission (reducer) in which the transmission ratio (reduction ratio) increases from the front transmission gear to the rear transmission gear. Therefore, depending on the order in which the transmission adjustment gear (430) is engaged, the number of rotations of the transmission adjustment gear (430) per one rotation of the output gear (300) can be changed and set.

To this end, preferably, a plurality of grooves (403a) are formed at intervals along the axial direction on the third transmission gear shaft (403) so as to be able to variably fix the forward/reverse direction position of the transmission adjustment gear (430).

In addition, an adjustment bolt (435) is connected to a through hole (430a) formed on one side of the gear adjustment gear (430) to fix the forward/backward position of the gear adjustment gear (430) corresponding to the position of any one of the plurality of grooves (403a).

For example, the closer the forward/rearward position of the above-described gear adjustment (430) is fixed to the front end, the lower the reduction ratio becomes in the process of transmitting rotational power from the output gear (300) to the gear adjustment gear (430), and the closer the forward/rearward position of the above-described gear adjustment (430) is fixed to the rear end, the higher the reduction ratio becomes in the process of transmitting rotational power from the output gear (300) to the gear adjustment gear (430).

Fig. 7 illustrates a case where the above-described shift adjustment gear (430) is engaged with the second first shift gear 410-2 from the front end, and Fig. 8 illustrates a case where the above-described shift adjustment gear (430) is engaged with the fourth first shift gear 410-4 from the front end. In the case of Fig. 8, the reduction ratio is set to be relatively higher in the process of transmitting rotational power from the output gear (300) to the shift adjustment gear (430) than in the case of Fig. 7. The shift adjustment gear (430) can also be engaged with the second shift gear (420) in the same manner.

For example, when the maximum number of rotations of the output gear (300) required for the indicator (520) to rotate 270 degrees to display “OPEN” and “CLOSE” is 100 rotations, when the output gear (300) rotates 150 and 200 degrees, the indicator (520) rotates multiple times.

However, since the position of the multi-rotation indicator (520) cannot be accurately determined on site, in the past, during the installation process of the electric actuator (A), the number of first transmission gears (410) and/or second transmission gears (420) installed in the transmission gear train (400) was increased or decreased, and the output gear (300) was installed on the first transmission gear shaft (401) or the second transmission gear shaft (402) by adjusting and setting the rotation speed.

However, in the case of this conventional method, there was a limitation that additional time may be required to prepare the additional gears when an additional transmission gear is required, but in the case of the configuration using the transmission adjustment gear (430) of the present embodiment, this limitation can be resolved, and the rotation speed of the transmission adjustment gear (430)/transmission output gear (440)/indicator (520) can be changed and set according to the rotation of the output gear (300) only by variably fixing the forward and backward position of the transmission adjustment gear (430) using the adjustment bolt (435) in the field.

The above encoder unit (200) will be described in more detail.

The encoder unit (200) of this embodiment includes a light-emitting unit (230) and a light-receiving unit (240).

The above-mentioned light-emitting unit (230) is installed on one side of any rotating disk (210) among the plurality of rotating disks (210) and is configured to change the direction of the LED light (L) projected from the LED (231) through the reflective surface (232) and pass through the pattern slit (211) of any rotating disk (210).

As illustrated in Fig. 10, the pattern slits (211) are arc-shaped slits formed at different radial positions so as to be concentric with respect to the central axis of each rotating disk (210). For example, depending on the rotation angle of each rotating disk (210), some of the LED lights (L) projected from the light-projecting unit (230) pass through the pattern slit (211) of the corresponding rotating disk (210), and some do not pass through. The LED lights (L) that pass through the pattern slit (211) are received by the photodiode of the light-receiving unit (240) arranged corresponding to the corresponding position, and an electronic position measurement signal regarding the rotational position of the rotating disk (210) is generated in the form of bit data. For example, an LED light (L) passing through a pattern slit (211) located on the outer side with respect to the radial direction of the rotating disk (210) represents an upper bit, and an LED light (L) passing through a pattern slit (211) located on the central side represents a lower bit, so that an electronic position measurement signal in the form of bit data can be generated for each rotating disk (210).

For example, the light-emitting part (230) is configured in the form of a dip type LED array in which a plurality of LEDs (231) are arranged along the radial direction of the arbitrary rotating disk (210). For example, the light-emitting part (230) is installed on the frame (FR) of the encoder unit (200) or a printed circuit board attached to the frame (FR), and is installed on the radially outer side of the rotating disk (210). The reflective surface (232) is installed on the radially inner side of the rotating disk (210) so as to face the light-emitting direction of the light-emitting part (230), and is installed so as to reflect the LED light (L) projected from the light-emitting part (230) in a direction bent by 90 degrees.

The above light receiving unit (240) is installed on the other side of the arbitrary rotating disk (210) and is configured to receive LED light (L) that has passed through the pattern slit (211), and is configured in the form of a light receiving element array in which a plurality of SMD type light receiving elements are arranged at positions corresponding to the LED array. For example, a photodiode (PD), an abalance photodiode, etc. may be used as the light receiving element. For example, the light receiving unit (240) is installed based on a frame (FR) of the encoder unit (200) or a printed circuit board attached to the frame (FR), and is installed on a substrate extending in the lateral direction of the rotating disk (210).

The encoder unit (200) of the present embodiment is configured so that the LED light (L) projected from the light-projecting portion (230) is reflected in a direction bent at 90 degrees from the reflecting surface (232), passes through the pattern slit (211) of the rotating disk (210), and is directly received by the light-receiving element of the light-receiving portion (240) installed on the opposite side of the rotating disk (210), so that light reception is possible through a path bent at 90 degrees. This light-projecting/receiving path configuration reduces the optical loss occurring during the reflection process and shortens the optical path, enabling more accurate and faster measurement, compared to the light-projecting/receiving path configuration that is bent at 180 degrees through two reflections proposed in the applicant's prior patent application No. 10-1452364 (October 13, 2014).

Preferably, the plurality of rotating disks (210) of the encoder unit (200) can transmit rotational force to each other through idle gears (220).

For example, at least one (e.g., 210-2) of the plurality of rotary disks (210) of the encoder unit (200) is rotatably installed on the first gear shaft (101) and has a rotary input gear (212-2) and a rotary output gear (213-2) each having a number of teeth according to a preset gear ratio on the front side and the rear side along the outer periphery.

The above-described rotating disk (e.g., 210-2) receives rotational power from one idle gear (e.g., 220-1) through the rotational input gear (212-2) and outputs rotational power to another idle gear (e.g., 220-2) through the rotational output gear (213-2).

For example, the rotating disk 210-2 has a rotating input gear 212-2 having n teeth (n>1) and a rotating output gear 213-2 having 1 tooth. Through this configuration, the rotating disk 210-2 provides a function of a transmission (reducer) in which the rotating input gear 212-2 receives rotational force from the idle gear 220-1 and rotates by n teeth, thereby rotating the idle gear 220-2 by 1 tooth through the rotating output gear 213-2 for each rotation.

For example, the encoder unit (200) illustrated in FIGS. 9 to 12 includes a total of four rotating disks (210). In this case, the example is for the second rotating disk (210-2), and the third rotating disk (210-3) illustrated in FIG. 12 may also have the same configuration.

The first rotary disk (210-1) is installed as an integral shaft-joint with the first gear shaft (101) and rotates together, so it does not receive rotational force from the idle gear.

The fourth rotating disk (210-4) is located at the end of the rotating disks and therefore does not transmit rotational power to the idle gear.

If the first to third rotating disks (210-1) to (210-3) each have a tooth ratio of 1/n based on the output/input, through the above configuration, the first rotating disk (210-1) receives the rotational force of the first gear shaft (101) and rotates integrally, the second rotating disk (210-2) receives the rotational force of the first rotating disk (210-1) through the first idle gear (220-1) and rotates at a reduced speed of 1/n, the third rotating disk (210-3) receives the rotational force of the second rotating disk (210-2) through the second idle gear (220-2) and rotates at a reduced speed of 1/n, and the fourth rotating disk (210-4) receives the rotational force of the third rotating disk (210-3) through the third idle gear (220-3) and rotates at a reduced speed of 1/n. The tooth count ratio of each output/input standard of the first rotating disk (210-1) to the third rotating disk (210-3) can be changed according to the design specifications.

The rotational position of each rotating disk (210-1 to 210-4) can be recognized using an electronic position measurement signal in the form of bit data generated by the light receiving unit (240) for each rotating disk (210).

By using the combination of the rotational positions of each of the rotating disks (210-1 to 210-4), the change in the rotational position of the first gear shaft (101) can be calculated, and through this, the control unit (50) can calculate the absolute rotational position of the valve drive shaft (32) based on the rotational speed relationship between the first gear shaft (101) and the valve drive shaft (32).

As a preferred example, the configuration of an encoder unit (200) including a total of four rotating disks (210) as illustrated in FIGS. 9 to 12 is described.

The above encoder unit (200) includes a first rotating disk (210-1), a first idle gear (220-1), a second rotating disk (210-2), a second idle gear (220-2), a third rotating disk (210-3), a third idle gear (220-3), and a fourth rotating disk (210-4).

The above first rotary disk (210-1) is integrally installed and coupled to the first gear shaft (101) and rotates together with it, has a first rotary output gear (213-1) having a number of teeth according to a preset gear ratio along the outer periphery, and has a pattern slit (211) forming a concentric track.

The above first idle gear (220-1) is rotatably installed on the second gear shaft (201) and receives rotational force from the first rotational output gear (213-1).

The second rotary disk (210-2) is rotatably installed on the first gear shaft (101) and has a second rotary input gear (212-2) and a second rotary output gear (213-2) each having a number of teeth according to a preset gear ratio on the front side and the rear side along the outer periphery, receives rotary force from the first idle gear (220-1) through the second rotary input gear (212-2), and has a pattern slit (211) forming a concentric track.

The above second idle gear (220-2) is rotatably installed on the second gear shaft (201) and receives rotational force from the second rotational output gear (213-2).

The third rotary disk (210-3) is rotatably installed on the first gear shaft (101) and has a third rotary input gear (212-3) and a third rotary output gear (213-3) each having a number of teeth according to a preset gear ratio on the front side and the rear side along the outer periphery, and receives rotary power from the second idle gear (220-2) through the third rotary input gear (212-3) and has a pattern slit (211) forming a concentric track.

The above third idle gear (220-3) is rotatably installed on the second gear shaft (201) and receives rotational force from the third rotational output gear (213-3).

The fourth rotary disk (210-4) is rotatably installed on the first gear shaft (101) and has a fourth rotary input gear (212-4) having a number of teeth according to a preset gear ratio along the outer periphery, receives rotary force from the third idle gear (220-3) through the fourth rotary input gear (212-4), and has a pattern slit (211) forming a concentric track.

With the above configuration, a first light-emitting part (230-1) is installed between the rear surface of the first rotating disk (210-1) and the front surface of the second rotating disk (210-2), and the LED light (L) emitted from the LED (231) of the first light-emitting part (230-1) is configured to be directed to the front and rear sides through the double-sided reflective surfaces (232a, 232b) and to pass through the pattern slits (211) of the first rotating disk (210-1) and the second rotating disk (210-2), respectively.

In addition, a second light-emitting part (230-2) is installed between the rear surface of the third rotating disk (210-3) and the front surface of the fourth rotating disk (210-4), and the LED light (L) emitted from the LED (231) of the second light-emitting part (230-2) is configured to be directed to the front and rear sides through the double-sided reflective surfaces (232a, 232b) and to pass through the pattern slits (211) of the third rotating disk (210-3) and the fourth rotating disk (210-4), respectively.

In addition, the first light receiving unit (240-1) installed on the front side of the first rotating disk (210-1) receives the LED light (L) that has passed through the pattern slit (211) of the first rotating disk (210-1).

In addition, the second light receiving unit (240-2) installed between the rear surface of the second rotating disk (210-2) and the front surface of the third rotating disk (210-3) receives the LED light (L) passing through the pattern slit (211) of the second rotating disk (210-2) and the LED light (L) passing through the pattern slit (211) of the third rotating disk (210-3), respectively. For example, the second light receiving unit (240-2) can receive both the LED light (L) projected from the LED (231) of the first light projecting unit (230-1) and the LED light (L) projected from the LED (231) of the second light projecting unit (230-2), and a light receiving element array is installed on the front surface of the printed circuit board and on the rear surface.

Additionally, the third light receiving unit (240-3) installed on the rear side of the fourth rotating disk (210-4) receives the LED light (L) that has passed through the pattern slit (211) of the fourth rotating disk (210-4).

The encoder unit (200) of the present embodiment is configured to arrange the first rotating disk (210-1) to the fourth rotating disk (210-4) in a row along the first gear shaft (101), and to install a light-emitting unit and a light-receiving unit in the space between them, and to install a double-sided reflective surface (232a, 232b) for bidirectional reflection of LED light (L), and to install a light-receiving element array on the front side and the rear side of the printed circuit board constituting the second light-receiving unit (240-2), thereby providing a compact configuration, and thereby preventing the size of the electric actuator (A) from increasing unnecessarily.

In addition, since the electric actuator (A) of this embodiment can have the control unit (50) recognize the absolute rotational position of the valve drive shaft (32) through the encoder unit (200), it is possible to accurately recognize the rotational position (open/close/opening degree) of the valve drive shaft (32) and perform rotational drive control accordingly without installing a mechanical limit switch or potentiometer that was previously installed.

In particular, since the electric actuator (A) of the present embodiment has the encoder unit (200) installed close to the input gear (100), the possibility of errors occurring in the measured value due to backlash of the gear train, etc. can be fundamentally prevented.

FIGS. 13 and 14 are perspective views showing the main components of a transmission gear train and an indicator section according to another embodiment of the present invention.

The transmission gear train (400) of this embodiment has a basic configuration common to the embodiments of FIGS. 10 to 12, but is configured so that the power transmission path of the rotational force of the transmission output gear (440) can be set differently depending on which of the first transmission gear (410) and the second transmission gear (420) is engaged with depending on the variable fixed forward/rearward position of the transmission adjustment gear (430), so that the rotational direction of the indicator (520) is maintained in the same direction regardless of the engagement state.

Referring to FIGS. 13 and 14, when the first transmission gear (410) rotates in the A2 direction, the second transmission gear (420) engaged therewith rotates in the symmetrical direction A3. Conversely, when the first transmission gear (410) rotates in the A1 direction, the second transmission gear (420) engaged therewith rotates in the symmetrical direction A4.

Therefore, depending on whether the above-mentioned gear adjustment (430) is engaged with the first gear (410) or the second gear (420), the rotation direction of the gear adjustment gear (430) and the gear output gear (440) can be in the A5 direction or the opposite direction, the A6 direction.

However, even if the rotational directions of the first transmission gear (410) and the second transmission gear (420) for the rotational drive position of the electric actuator (A) to become the "OPEN" position and the rotational directions of the first transmission gear (410) and the second transmission gear (420) for the rotational drive position of the electric actuator (A) to become the "CLOSE" position are maintained the same, the rotational directions of the transmission adjustment gear (430) and the transmission output gear (440) are changed to the A5 direction or the A6 direction depending on whether the transmission adjustment gear (430) is engaged with the first transmission gear (410) or the second transmission gear (420), so if the rotational directions are transmitted as they are to the indicator (520), depending on whether the transmission adjustment gear (430) is engaged with the first transmission gear (410) or the second transmission gear (420), The “OPEN” and “CLOSE” indication directions of the indicator (520) may be displayed in reverse.

In consideration of this, the transmission gear train (400) of the present embodiment is configured so that the power transmission path of the rotational force of the transmission output gear (440) can be set differently depending on which of the first transmission gear (410) and the second transmission gear (420) the transmission adjustment gear (430) is in mesh with, so that the rotational direction of the indicator (520) according to the rotational driving position of the electric actuator (A) is configured to maintain the same direction.

To this end, the transmission gear train (400) of the present embodiment is configured to include a first power transmission gear (492) and a second power transmission gear (494).

The first power transmission gear (492) is rotatably installed on the end side of the first transmission gear shaft (401) and is installed to mesh with the transmission output gear (440).

The second power transmission gear (494) is installed in a rotatably axially coupled manner on the end side of the second transmission gear shaft (402), and is installed so that a portion of the width of the teeth of the gear meshes with the first power transmission gear (492), and another portion of the width of the teeth of the gear does not mesh with the first power transmission gear (492).

Through the above configuration, the transmission gear train (400) of the present embodiment is configured such that the position input gear (510) is installed by moving the position input gear (510) forward (F) or backward (R) on the third gear shaft (501), thereby having a first installation state in which the position input gear (510) meshes with the first power transmission gear (492) to receive rotational force, or a second installation state in which the position input gear (510) meshes with the second power transmission gear (494) to receive rotational force. The position input gear (510) can be installed by moving the position input gear (510) forward (F) or backward (R) on the third gear shaft (501) through various known gear fixing structures.

Fig. 13 shows a case where the gear adjustment gear (430) is installed to mesh with the second transmission gear 420-2 located in the second order among the second transmission gears (420) according to the variable fixed forward/backward position. In this case, as the position input gear (510) is installed by moving the position to the rear (R) on the third gear shaft (501), the position input gear (510) is engaged with the second power transmission gear (494) to receive rotational force in a second installation state.

For example, when the second transmission gear (420) rotates in the A4 direction, the gear adjustment gear (430) and the gear output gear (440) engaged with it rotate in the symmetrical direction A5, the first power transmission gear (492) engaged with the gear output gear (440) rotates in the symmetrical direction A2, the second power transmission gear (494) engaged with the first power transmission gear (492) rotates in the symmetrical direction A3, and the indicator (520) integrally connected through the position input gear (510) and the third gear shaft (501) engaged with the second power transmission gear (494) rotates in the symmetrical direction A8.

In this process, the second power transmission gear (494) is installed so that a portion of the tooth width of the gear (front portion) is engaged with the first power transmission gear (492) and another portion of the tooth width of the gear (rear portion) is not engaged with the first power transmission gear (492), and is installed so as to engage with the position input gear (510), thereby transmitting the rotational power received from the first power transmission gear (492) to the position input gear (510).

Fig. 14 shows a case where the gear adjustment gear (430) is installed to mesh with the first transmission gear 410-2 located in the second order among the first transmission gears (420) according to the variable fixed forward/backward position. In this case, as the position input gear (510) is installed by moving the position forward (F) on the third gear shaft, the position input gear (510) is engaged with the first power transmission gear (492) to have a first installation state in which rotational force is input.

As in the previous example, when the second transmission gear (420) rotates in the A4 direction, the first transmission gear (410) rotates in the A1 direction, and the gear adjustment gear (430) and the gear output gear (440) engaged therewith rotate in the symmetrical direction A6, the first power transmission gear (492) engaged with the gear output gear (440) rotates in the symmetrical direction A1, and the indicator (520) integrally connected through the position input gear (510) and the third gear shaft (501) engaged with the first power transmission gear (492) rotates in the symmetrical direction A8. As a result, it can be seen that even if the engagement state of the gear adjustment gear (430) changes, the rotational direction of the indicator (520) is not affected.

In this process, the second power transmission gear (494) engaged with the first power transmission gear (492) rotates in the A4 direction, but is not engaged with the position input gear (510) and therefore does not participate in transmitting rotational power to the position input gear (510).

Through the above configuration, the transmission gear train (400) of the present embodiment is configured to set the power transmission path of the rotational force of the transmission output gear (440) differently depending on which of the first transmission gear (410) and the second transmission gear (420) it is in mesh with, so that the rotational direction of the indicator (520) can be maintained in the same direction regardless of the meshing state.

While the present invention has been described with reference to the accompanying drawings, focusing on preferred embodiments, it will be apparent to those skilled in the art that numerous obvious modifications are possible without departing from the scope of the invention. Therefore, the scope of the present invention should be construed as encompassing these numerous modifications as defined by the claims.

2: Casing
10: Motor
12: Motor shaft
14: Power transmission mechanism
20: Worm
22: Worm axis
30: Worm wheel
32: Valve drive shaft
34: Ring gear
36: Transmission gear train
100: Input gear
101: First gear shaft
200: Encoder unit
201: Second gear shaft
210: Rotating disk
211: Pattern Slit
220: Idle Gear
230: Projector
240: Photoreceptor
300: Output gear
400: Transmission gear train
401,402,403: Transmission shaft
410,420: Transmission
440: Shift output gear
500: Indicator section
501: Third gear shaft
510: Position input gear
520: Indicator
A: Electric actuator
L: LED light
PU: Position Measuring Unit

Claims (10)

A transmission gear train comprising: at least one first transmission gear rotatably installed on a first transmission gear shaft; at least one second transmission gear rotatably installed on a second transmission gear shaft arranged parallel to the first transmission gear shaft and meshed with the first transmission gear; a gear adjustment gear rotatably installed on a third transmission gear shaft arranged parallel to the first transmission gear shaft and having a variably fixed forward/backward position, meshing with one of the at least one first transmission gear and the at least one second transmission gear according to the variably fixed forward/backward position, and receiving a rotational force input based on the first transmission gear by changing it at a gear ratio determined according to an engagement position based on a forward/backward position; and a gear output gear integrally installed on the third transmission gear shaft and rotating together therewith; and
A position measuring unit comprising: an indicator unit, which includes a position input gear that receives rotational force shifted from the shift output gear side and is coupled to one end of a gear shaft arranged parallel to the third transmission gear shaft, and an indicator unit that displays a mechanical position measurement result on the other end.
In the first paragraph,
The above first transmission gear has a configuration in which a first transmission input gear and a first transmission output gear having different sizes and having a number of teeth according to a preset gear ratio along the outer periphery are integrally combined.
The above second transmission gear has a configuration in which a second transmission input gear and a second transmission output gear having different sizes and having a number of teeth according to a preset gear ratio along the outer periphery are integrally combined.
The first transmission gear rotates by receiving rotational force through the first transmission input gear,
A position measuring unit characterized in that the second transmission gear rotates by receiving rotational force from the first transmission output gear through the second transmission input gear.
In the second paragraph,
Two or more first transmission gears are installed on the first transmission gear shaft,
Two or more second transmission gears are installed on the second transmission gear shaft,
A position measuring unit characterized in that at least one of the two or more first transmission gears rotates by receiving rotational force from the second transmission output gear of one of the two or more second transmission gears through the first transmission input gear.
In the first paragraph,
The third gear shaft has a plurality of grooves formed at intervals along the axial direction,
A position measuring unit characterized in that an adjustment bolt is connected through a through hole formed on one side of the above-mentioned gear to fix the forward/backward position of the above-mentioned gear corresponding to the position of any one of the plurality of grooves.
In the first paragraph,
An input gear that receives rotational force by being coupled to one end of a first gear shaft arranged parallel to the first transmission gear shaft;
An encoder unit that generates an electronic position measurement signal, including a plurality of rotating disks that are axially coupled to the first gear shaft and spaced apart from each other in parallel and having pattern slits forming concentric tracks, a plurality of idle gears that are axially coupled to the second gear shaft arranged parallel to the first gear shaft and that transmit rotational force between the plurality of rotating disks, a light-emitting unit that projects LED light to pass through the pattern slits of the rotating disks, and a light-receiving unit that receives the LED light passing through the pattern slits; and
An output gear that is coupled to the other end of the first gear shaft and outputs rotational force;
The above gear train is,
A position measuring unit characterized by receiving rotational force from the above output gear.
In paragraph 5,
The above encoder unit,
The above light-emitting unit is installed on one side of any rotating disk among the plurality of rotating disks, and is configured to change the direction of the LED light emitted from the LED through a reflective surface and pass through the pattern slit of any rotating disk.
A position measuring unit characterized in that the light receiving unit is installed on the other side of the arbitrary rotating disk and is configured to receive LED light passing through the pattern slit.
In paragraph 5,
At least one of the plurality of rotating disks of the encoder unit,
The first gear shaft is installed in a rotatably connected state,
It has a rotation input gear and a rotation output gear, each having a number of teeth according to a preset gear ratio on the front side and the rear side along the outer periphery, respectively.
A position measuring unit characterized in that it receives rotational force from one idle gear through the rotational input gear and outputs rotational force to another idle gear through the rotational output gear.
In the first paragraph,
The above gear train is,
A first power transmission gear that is rotatably installed on the end side of the first transmission gear shaft and is engaged with the transmission output gear; and
A second power transmission gear is installed in a rotatably coupled manner on the end side of the second transmission gear shaft, and is installed such that a portion of the width of the teeth of the gear meshes with the first power transmission gear and another portion of the width of the teeth of the gear does not mesh with the first power transmission gear;
A position measuring unit characterized in that the position input gear has a first installation state in which it meshes with the first power transmission gear and receives rotational force, or a second installation state in which it meshes with the second power transmission gear and receives rotational force, by moving the position input gear forward or backward on a gear shaft arranged parallel to the third transmission gear shaft.
A transmission gear train in which at least one transmission gear is installed based on two transmission gear shafts arranged in parallel, and a transmission adjustment gear whose front-rear position can be variably fixed and a transmission output gear that outputs rotational force are installed based on another transmission gear shaft arranged in parallel with the two transmission gear shafts, rotational force is input based on one of the transmission gears, and the transmission adjustment gear meshes with one of the transmission gears, and the input rotational force is output through the transmission output gear at a transmission ratio determined according to an engagement position based on the front-rear position of the transmission adjustment gear; and
A position measuring unit comprising: an indicator unit, which includes a position input gear that receives a rotational force shifted from the gear output gear side and is coupled to one end of a gear shaft arranged parallel to another gear shaft, and an indicator unit that displays a mechanical position measurement result on the other end.
An electric actuator comprising a position measuring unit of any one of claims 1 to 9,
The rotational power of the motor shaft is transmitted to the worm shaft on which the worm is installed through the power transmission mechanism,
The rotational power of the worm is transmitted to the valve drive shaft through a worm wheel installed coaxially to the valve drive shaft,
The above motor shaft, worm shaft and valve drive shaft are supported so as to be rotatable based on the casing,
An electric actuator characterized in that the position measuring unit receives rotational force through a transmission gear train that receives rotational force from a ring gear installed coaxially on the valve drive shaft.