JPH06281867A - Rotation driving device - Google Patents

Abstract

(57) [Abstract] [Purpose] For example, a rotating structure such as a lens barrel or a pedestal of an optical infrared telescope for astronomical observation can always be smoothly rotated,
A rotary drive device that does not generate friction torque, meshing loss torque, stick-slip, or the like in the rotary drive mechanism system, does not cause structural deformation of the rotary structure, and can easily realize extremely high-precision rotary drive is obtained. Especially. [Structure] The linear motors 16 and 17 are attached to the rotating structures 1 and 6.
The rotating side and the fixed side are directly attached.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drive device for rotationally driving a structure such as a lens barrel or a mount of an optical infrared telescope for tracking and observing a celestial body around a support shaft.

[0002]

2. Description of the Related Art FIG. 10 is an overall perspective view showing a conventional reflection-type large-diameter optical infrared telescope apparatus, FIG. 11 is a sectional view of FIG. 10, and FIG. 12 is a main part of a lens barrel drive system in FIGS. FIG. 13 is a front view, FIG. 13 is a side view of FIG. 12, FIG. 14 is a front view of a main part of a gantry drive system, and FIG. 15 is a plan view of FIG.
In the figure, 1 is a mount for an infrared telescope for astronomical observation,
2 is an Az axis which supports the gantry 1 so as to be horizontally rotatable,
3 is a plurality of motors mounted on the gantry 1, and 4 is a plurality of motors fitted and coupled to the output shafts of the motors 3 (4 in the figure).
5) are driving gears (driving gears) 5 which are fixed to the floor on which the gantry 1 is installed with the Az shaft 2 as a center, and the driving gear 4 meshes with the ring gear 5 to drive the driving gears. The gear is adapted to be synchronously driven by the motor 3.

Therefore, the motor 3, the driving gear 4 and the ring gear 5 constitute a gantry rotation drive mechanism A for horizontally rotatably driving the gantry 1 around the Az axis 2.

Reference numeral 6 denotes a lens barrel composed of a reflecting mirror support structure mounted on the gantry 1, 7 is an El shaft which pivotally supports the lens barrel 6 on the gantry 1, and 8 is an El shaft. A lens barrel drive system motor mounted and fixed to the mount 1 in the vicinity of 7.
A main driving gear (main driving gear) 9 is fitted and coupled to the output shaft of the motor 8.

Reference numeral 10 denotes a driven gear (final stage gear) fitted and coupled to the El shaft 7, and the driven gear 9 is meshed with the driven gear 10. Therefore, the motor 8 and the driving gear 9
The driven gear 10 constitutes a lens barrel raising / lowering mechanism B which drives the lens barrel 6 to rotate around the El axis 7 in a vertical direction.

Reference numeral 11 denotes a main reflecting mirror attached to the lower portion of the lens barrel 6 for collecting parallel rays from an observing celestial body, and 12 denotes a sub-reflector attached to the lens barrel 6 at a position facing the main reflecting mirror 11 above. A reflecting mirror 13 is a Cassebren focal point which is an astronomical observation position, and a photographing object such as a photographic dry plate is set at the position of the Cassebren focal point 13.

Next, the operation will be described. For astronomical observation, first open the observation port (not shown) of the telescope dome and point the telescope at the astronomical object to be observed. In this case, when the gantry 1 drive system is activated, the main drive gear 4 of this system is rotationally driven, and the main drive gear 4 rolls along the ring gear, so that the gantry 1 rotates horizontally about the Az axis 2. Move. Further, when the motor 8 of the drive system of the lens barrel 6 is started, the driven gear 10 is rotationally driven via the main gear 9 of this system, so that the lens barrel 6 turns up and down about the El shaft 7.

In this way, the gantry 1 is horizontally rotated to a predetermined rotation angle and the lens barrel 6 is rotationally driven to a predetermined depression / elevation angle, so that the telescope captures an astronomical object to be observed. To track. Then, the parallel light rays from the observing celestial body pass through the sub-reflecting mirror 12 and then the main reflecting mirror 11.
By irradiating the photographic dry plate, which has been focused at 1, and is set at the Cassebrene focus 13, the photographic dry plate is exposed for a certain period of time, and an astronomical image is captured.

Therefore, the rotation drive mechanism A for the Az axis 2 and the rotation drive mechanism B for the El axis 7 accurately adjust the pedestal 1 and the lens barrel 6 so that the celestial body is always captured during observation in accordance with the movement of the celestial body. Need to keep spinning well.

Here, each of the rotary drive mechanisms A and B has a driving gear 4, a ring gear 5, a driving gear 9 and a driven gear 1.
In order to remove backlash between 0 and improve rigidity, a certain pre-torque (± Tp) is always applied in one pair or more for use.

Now, assuming that the load torque around the axis is T _L , the torque (Tn) generated by each drive motor 6 of each rotary drive mechanism has the following relationship. In the case of the El-axis rotary drive mechanism (two drive motors 6), T _z = (1/2) T _L + T _P and T _M = (1/2) T
If _L -T _P Az axis rotation drive mechanism (drive motor 6 is _{four), T M = (1/4)} T L + T P (2 units 4 units), and T _M = (1/4) T _L -T _P (2 remaining out of 4).

As described above, in order to obtain an image of the celestial body, it is necessary for the photographic plate to continue exposure for a certain period of time. In order to form a clear image on the photographic plate, it is synchronized with the movement of the celestial body. It is necessary to drive the gantry 1 and the lens barrel 6 with high accuracy.

[0013]

Since the conventional rotation drive device for the astronomical telescope is constructed as described above,
Friction torque of bearings present in the rotary drive mechanisms A and B of the gantry 1 system and the lens barrel 6 system, the driving gear 4 and the ring gear 5
Also, the load torque fluctuates due to fluctuations in the engagement loss torque between the main driving gear 9 and the driven gear 10 and stick-slip, and it is not possible to obtain a clear celestial image capable of smoothly rotating the gantry 1 and the lens barrel 6. There was a point.

Also, for the anti-bush flash drive for preventing the rattling of the lens barrel 6 around the El axis 7 and the rattling of the mount 1 around the Az axis 2 due to the backlash of the meshing portions of the respective gears. Since the ratio of the pre-torque transmitted to the lens barrel 6 and the gantry 1 changes in accordance with the fluctuation of the load torque, the structural deformation amount of the lens barrel 6 and the gantry 1 also changes to change the main reflecting mirror 11 and the sub-reflecting mirror. There is a problem that the relative position with respect to 12 is changed, and as a result, the sharpness of the astronomical image is reduced.

The present invention has been made to solve the above problems, and an object of the inventions of claims 1 and 2 is to provide a friction torque existing in each rotation drive mechanism of the mount and the lens barrel. The purpose of the present invention is to obtain a rotary drive device in which the engagement loss torque and stick slip do not occur, and the structure of the mount and the lens barrel is not deformed by the operation of the rotary drive mechanism.

The objects of the inventions of claims 3 and 4 are:
The electromagnetic attraction force generated between the rotating side and the fixed side of the linear motor that drives the rotating structure can be canceled out, and this electromagnetic attracting force does not act on the rotating structure to prevent the outer rotating structure from being deformed. To obtain a rotation drive device that can be prevented.

[0017]

According to a first aspect of the present invention, there is provided a rotary drive device for rotationally driving a gantry such as an astronomical observation telescope device and a rotary structure such as a lens barrel in an axial direction. The rotating side and the fixed side of the linear motor are directly attached to the rotating structure.

In the rotary drive device according to the second aspect of the present invention, the linear motor for driving the rotary structure is composed of electromagnetic coils or combinations of electromagnetic coils and permanent magnets, and these electromagnetic coils or electromagnetic coils and permanent magnets. One or both of the above are arranged in an arc shape or a circular shape coaxial with the rotation center of the rotary structure.

In the rotary drive device according to the third aspect of the present invention, the linear motor for driving the rotary structure is composed of electromagnetic coils or a combination of electromagnetic coils and permanent magnets, and these electromagnetic coils or electromagnetic coils and permanent magnets. Are symmetrically arranged at the same position on both front and back surfaces of the rotating structure.

According to a fourth aspect of the present invention, in the rotary drive device, the electromagnetic coils or permanent magnets of the linear motor are symmetrically directly mounted at the same positions on both front and back surfaces of the sector wheel integrally connected to the rotary shaft of the rotary structure. The electromagnetic coil is arranged opposite to the electromagnetic coil or the permanent magnet via a predetermined gap.

[0021]

In the rotary drive device according to the first aspect of the present invention, since the rotating (moving) side and the fixed side of the linear motor are directly attached to the rotary structure, the gear transmission for transmitting the rotary drive force to the rotary structure. No need for friction transmission or other power transmission mechanism,
Rigidity reduction, mechanical loss, fluctuation of driving force, and load other than the driving direction do not occur, the rotation control accuracy of the rotating structure is significantly improved, and deformation of the rotating structure due to the load other than the driving direction is prevented. Lost. Therefore, when the rotary drive device of the present invention is applied to a telescope device for astronomical observation, it is possible to drive the lens barrel and the gantry in synchronization with the movement of the astronomical object. Further, as described above, since there is no change in the relative position between the main reflecting mirror and the sub-reflecting mirror caused by the structural deformation, a clear image can be formed on the photographic plate.

According to another aspect of the present invention, the linear motor comprises electromagnetic coils or a combination of electromagnetic coils and permanent magnets, and the electromagnetic coils or one or both of the electromagnetic coils and the permanent magnets are the same. Since the rotary structure is arranged in an arc shape or a circular shape coaxial with the center of rotation of the rotary structure, the rotary structure is made to have a predetermined size by applying an electromagnetic attractive force between the electromagnetic coils or between the electromagnetic coils and the permanent magnet. It can be smoothly rotated in the direction of, and the same effect as in the case of the above-mentioned claim 1 can be obtained.

In the rotary drive device according to the third aspect of the present invention, since the linear motor for driving the rotary structure has the electromagnetic coils or the electromagnetic coils and the permanent magnets arranged symmetrically at the same position on the front and back surfaces of the rotary structure. Electromagnetic attraction that occurs between the electromagnetic coil on the rotating side of the linear motor or one of the electromagnetic coil and the permanent magnet, and the electromagnetic coil on the fixed side of the linear motor or the other of the electromagnetic coil and the permanent magnet. Since the forces are offset and the electromagnetic attraction force does not act on the rotating structure, it is possible to prevent deformation of the rotating structure due to the electromagnetic attraction force.

In the rotary drive device according to the invention of claim 4, the electromagnetic coil or the permanent magnet of the linear motor is symmetrically directly mounted at the same position on both front and back surfaces of the sector wheel integrally connected to the rotary shaft of the rotary structure. Since the electromagnetic coil is arranged so as to face the electromagnetic coil or the permanent magnet via a predetermined gap, the same effect as in the case of the above-mentioned claim 5 is obtained.

[0025]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view showing a rotation drive device for a gantry of a telescope apparatus for astronomical observation according to Embodiment 1 of the present invention, and FIG.
FIG. 16 is a plan view of an essential part of FIG. In the figure, 1a is an annular groove formed in the lower circular peripheral wall of the gantry 1 as a rotating structure, 15 is a circular annular guide rail fixedly installed on the floor of the gantry 1, and 15a is a guide rail 15 of the guide rail 15. The annular flange portion is integrally formed on the inner peripheral surface, and the annular groove 1a is loosely fitted in the annular flange portion 15a.

Reference numeral 16a denotes an electromagnetic coil mounted directly on the upper and lower opposite surfaces of the annular groove 1a, and 16b denotes the guide rail 1
5 is an arc-shaped or circular permanent magnet that is directly attached to the front and back surfaces of the annular flange 15a at the same position and faces the electromagnetic coil 15a, and the pedestal 1 is provided by the electromagnetic coil 16a and the permanent magnet 16b. Az axis (rotation axis)
A linear motor 16 that is driven to rotate horizontally around two is configured, and the electromagnetic coil 16 in the linear motor 16 is configured.
A predetermined gap g is provided between a and the permanent magnet 16b.

FIG. 3 is a front view of an essential part showing a rotary driving device for the lens barrel supported by the mount of FIG. 1, and FIG. 4 is a side view of the essential part of FIG. 3, in which 14 is a rotating structure. E of lens barrel 6
The sector wheel integrally connected to the l-axis 7, 17a is an electromagnetic coil directly attached to the gantry 1 at opposing positions sandwiching the sector wheel 14, and 17b is the sector wheel 1
4 is an arc-shaped or circular permanent magnet that is directly attached to the front and back surfaces at the same position and faces the electromagnetic coil 17a. The electromagnetic coil 17a and the permanent magnet 17b move the lens barrel 6 into the El axis ( A linear motor 17 that is driven to rotate up and down is configured around a rotation axis 7 and the electromagnetic coil 17a and the permanent magnet 1 in the linear motor 17 are configured.
A predetermined gap g is also provided between it and 7b.

Therefore, the electromagnetic coil 16a is integral with the gantry 1, and the electromagnetic coil 17a is integral with the lens barrel 6, and these electromagnetic coils 16a and 16b surround the respective Az axis 2 and El axis 7. It will rotate to.

In the first embodiment, the Az axis 2
By appropriately determining the distance from the El shaft 7 to the electromagnetic coils 16a and 17a and the number of these electromagnetic coils 16a and 17a, the electromagnetic coils 16a and 1
As for 7a, the same product can be used.

Next, the operation will be described. When observing an astronomical object, first open the observation port (not shown) of the telescope dome, and operate the linear motor 16 of the system of the gantry 1 so that the lens barrel 6 faces the direction of the astronomical object to be observed, as in the conventional case. Then, the gantry 1 is horizontally rotated, and the linear motor 17 of the lens barrel 6 system is also operated to vertically rotate the lens barrel 6 at a predetermined angle to capture the celestial object to be observed.

After that, for example, a photographic plate is accurately placed at the position of the Cassebren focal point 13 (see FIG. 11), astronomical observation is started in this state, and the gantry 1 is mounted by the linear motors 16 and 17 so as to synchronize with the movement of the celestial body. The lens barrel 6 is driven to continue capturing the celestial body, and exposure to the photographic plate is continued for a certain period of time to obtain an celestial image on the photographic plate.

In this case, the pre-torque (± Tp) described in the prior art is unnecessary, and if the load torque around the shaft is T _L , the torque (T _M ) generated by the thrust of the linear motors 16 and 17 is It has the relationship of the following formula. E _L- axis rotary drive linear motor 10 (2 units) T _M = (1/2) T _L (per unit) Az-axis rotary drive linear motor 11 (4 units) T _M = (1 / 4) _TL (per unit)

The structural deformation of the gantry 1 or the lens barrel 6 due to the electromagnetic attractive force generated between the electromagnetic coils 16a and 17a and the permanent magnets 16b and 17b is so small as to be negligible, and the main reflecting mirror 11 due to this structural deformation. When the change in the relative position between the sub-reflecting mirror 12 and the sub-reflecting mirror 12 is small enough to be neglected, it is not necessary to use the suction force to cancel the linear motors as in the first embodiment. .

Example 2. 5 is a partial front view showing a cradle drive system of a rotary drive apparatus according to a second embodiment of the present invention, in which a main part is broken away, and FIG. 6 is a side view of the main part of FIG. In the first embodiment, the permanent magnets 16b of the linear motor 16 are arranged on both front and back surfaces of the inward annular flange 15a of the guide rail 15, but in the second embodiment, linear magnets are formed on both inner and outer peripheral surfaces of the circular annular guide rail 15. The permanent magnet 16b of the motor 16 is directly mounted, and the electromagnetic coil 16a that sandwiches the permanent magnet 16b with a predetermined gap g is arranged in the lower portion of the gantry 1.

FIG. 7 is a partial front view showing a lens barrel drive system of a rotary drive apparatus according to a second embodiment of the present invention, with a main part broken away.
FIG. 8 is a side view of the main part of FIG. In the first embodiment, the permanent magnets 17b of the linear motor 17 are arranged on the front and back surfaces of the sector wheel 14. In the second embodiment, the free end of the sector wheel 14 has a flange portion 14a extending outward in the horizontal direction.
The permanent magnets 17b of the linear motor 17 are directly mounted on both front and back surfaces of the collar portion 14a, and an electromagnetic coil 17a that sandwiches the permanent magnets 17b with a predetermined gap g is provided on the gantry 1 side. It is attached to the. Therefore, also in the case of the second embodiment, the same effect as that of the above-described embodiment is obtained.

Example 3. FIG. 9 is a schematic diagram showing the construction of a main part of a rotary drive device according to a third embodiment of the present invention. In the second embodiment, the electromagnetic coils 16a, 17a have been described as arcuate in shape.
It is not always necessary that a and 17a have an arc shape. In the third embodiment, each of the electromagnetic coils 16a and 17a has a flat plate shape, and the electromagnetic coils 16a and 17a are arranged at positions facing the permanent magnets 16b and 17b, and an air gap g between them is reduced. It is configured to be within the allowable range, and even in this case, the same effect as in the case of the previous embodiment can be obtained.

Example 4. In the first and second embodiments, the sector wheel 14 is provided with the permanent magnet 17b of the linear motor 17 and the gantry 1 is provided with the electromagnetic coil 17a of the linear motor 17, but the reverse is the case. The sector coil 14 may be equipped with an electromagnetic coil 17a, and the gantry 1 may be equipped with a permanent magnet 17b.
The same effect as 2 is achieved.

Example 5. In the above-mentioned Examples 1 and 2,
The permanent magnet 16b of the linear motor 16 is attached to the circular annular guide rail 15, and the electromagnetic coil 1 of the linear motor 16
Although the case where 6a is mounted on the gantry 1 has been described, conversely, the electromagnetic coil 16a is attached to the guide rail 15 and
Moreover, the permanent magnet 16b may be mounted on the gantry 1, and even in this case, the same effect as that of the above-described embodiment can be obtained.

Example 6. Further, in each of the above-mentioned embodiments, the case where the linear motors 16 and 17 including the electromagnetic coils 16a and 17a and the permanent magnets 16b and 17b are used is described. However, these linear motors 16 and 17 include the electromagnetic coils and the electromagnetic coils. Alternatively, it may be composed of a combination of an electromagnetic coil and an electromagnetic coil with a permanent magnet, and in this case, the same effect as that of each of the above-described embodiments can be obtained.

[0040]

As described above, claim 1 and claim 2 are as follows.
According to the invention, since the rotary structure is rotationally driven by the linear motor, and the rotary side and the fixed side of the linear motor are directly attached to the rotary structure, the rotary drive system for the rotary structure is There is no backlash, the decrease in rigidity is extremely small, there is no mechanical loss of the rotational drive force, and there is no fluctuation in the rotary structure due to the rotary drive mechanism, and the rotational position control of the rotary structure can be performed easily and with high accuracy. effective.

According to the inventions of claims 3 and 4,
Since the linear motor that drives the rotating structure is configured such that the electromagnetic coils or the electromagnetic coils and the permanent magnets are symmetrically arranged at the same position on the front and back surfaces of the rotating structure, the electromagnetic coil that is the rotating side of the linear motor. Alternatively, it is possible to cancel an electromagnetic attraction force generated between one of the electromagnetic coil and the permanent magnet and the other of the electromagnetic coil or the electromagnetic coil and the permanent magnet, which is the fixed side of the linear motor, and to cancel the electromagnetic attraction. Since the force does not act on the rotating structure,
There is an effect that deformation of the rotary structure due to the electromagnetic attraction force can be prevented in advance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a rotation drive device for a gantry of an astronomical observation telescope device according to Embodiment 1 of the present invention.

FIG. 2 is a plan view of an essential part of FIG.

3 is a front view of relevant parts showing a rotation driving device for a lens barrel supported by the mount of FIG. 1. FIG.

FIG. 4 is a plan view of an essential part of FIG.

FIG. 5 is a partial front view showing a gantry drive system of a rotary drive apparatus according to a second embodiment of the present invention with a main part cut away.

FIG. 6 is a side view of a main part of FIG.

FIG. 7 is a partial front view in which a main part showing a lens barrel drive system of a rotation drive device according to a second embodiment of the present invention is broken away.

FIG. 8 is a side view of a main part of FIG.

FIG. 9 is a schematic diagram illustrating the configuration of a main part of a rotation drive device according to a third embodiment of the present invention.

FIG. 10 is an overall perspective view showing a conventional reflection-type large-diameter optical infrared telescope device.

11 is a cross-sectional view of FIG.

12 is a front view of relevant parts of the lens barrel drive system in FIGS. 10 and 11. FIG.

FIG. 13 is a side view of FIG.

14 is a front view of the main parts of the gantry drive system in FIGS. 10 and 11. FIG.

FIG. 15 is a plan view of FIG.

[Explanation of symbols]

 1 Frame (Rotating Structure) 2 Az Axis (Rotating Axis) 6 Lens Bar (Rotating Structure) 7 El Axis (Rotating Axis) 14 Sector Wheel 16 Linear Motor 16a Electromagnetic Coil 16b Permanent Magnet 17 Linear Motor 17a Electromagnetic Coil 17b Permanent Magnet

Claims (4)

[Claims] 1. A rotary drive device for rotationally driving a rotating structure such as a gantry and a lens barrel of an astronomical observing telescope device around a rotation axis, and the rotating side and the fixed side of a linear motor are directly attached to the rotating structure. A rotary drive device characterized in that 2. The linear motor is composed of electromagnetic coils or a combination of electromagnetic coils and a permanent magnet, and one or both of the electromagnetic coils or one of the electromagnetic coils and the permanent magnet is coaxial with a rotation center of the rotary structure. The rotary drive device according to claim 1, wherein the rotary drive device is arranged in a circular arc shape or a circular shape of a center. 3. The linear motor comprises electromagnetic coils or a combination of electromagnetic coils and permanent magnets, and the electromagnetic coils or the electromagnetic coils and permanent magnets are symmetrically arranged at the same position on both front and back surfaces of the rotary structure. The rotation drive device according to claim 1, wherein: 4. A sector wheel is integrally connected to a rotary shaft of the rotary structure, and an electromagnetic coil or a permanent magnet is directly and symmetrically mounted at the same position on both front and back surfaces of the sector wheel. 4. The rotary drive device according to claim 2, wherein an electromagnetic coil is arranged opposite to the permanent magnet with a predetermined gap therebetween.