KR20140145340A - Planetary Gear Apparatus - Google Patents

Abstract

The present invention relates to a planetary gear device. According to an embodiment of the present invention, even if the gear teeth of the planetary gears and the gear teeth of the sun gears are worn, the elastic support pushes the planetary gears toward the center of the carrier, The clearance between the sun gears is compensated to thereby prevent noise from being generated.

Description

[0001] Planetary Gear Apparatus [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary gear device, and more particularly, to a planetary gear device that includes an input shaft, To a planetary gear device capable of preventing generation of noise by compensating for a clearance.

1 is a configuration diagram of an active front wheel barrel apparatus of a conventional automobile. 2 is a cross-sectional view schematically showing a gear ratio converting apparatus of an active front wheel steering apparatus of a conventional automobile.

1, an active front wheel steering apparatus of a conventional automobile includes a steering wheel 101, a steering shaft 103 connected to the steering wheel 101, a steering column 105 surrounding the steering shaft 103, An input angle sensor 107 formed at the lower end of the steering column 105, a gear ratio conversion device 109 formed below the input angle sensor 107, a first motor 111 for driving the gear ratio conversion device 109 A first motor position sensor 113 provided in the first motor 111, an output angle sensor 115 provided below the gear ratio converter 109, a vehicle speed sensor 117 for detecting the speed of the vehicle, A rack-and-pinion mechanism portion 121 formed below the gear ratio converter 109 for converting the rotational motion of the steering shaft 103 into a linear motion of the rack bar 119, An electronic control unit for receiving various signals from the second motor 123, the input angle sensor 107, the first motor position sensor 113 and the output angle sensor 115 a ctronic control unit (ECU) 125, and the like.

2, the conventional gear ratio conversion apparatus includes an input shaft 210, a first sun gear 220 formed at the lower end of the input shaft 210, a first sun gear 220 external to the first sun gear 220, A second planetary gear 280 connected to the first planetary gear 270 via a planetary gear shaft 275, a second planetary gear 280 coupled to the second planetary gear 280 and a second sun gear 230 An output shaft 240 connected to the second sun gear 230, a worm wheel 250 and a worm 260, and the like.

The operation principle of the active front wheel steering apparatus and the gear ratio conversion apparatus of the conventional automobile having such a configuration is as follows.

When the driver rotates the input shaft 210 as the steering wheel 101 is operated, the first sun gear 220 formed at the lower end of the input shaft 210 rotates in conjunction with the input shaft 210.

In this case, the first planetary gear 270, which is in contact with the first sun gear 220, rotates, and the second planetary gear train 270, which is connected to the first planetary gear 270 via the planetary gear shaft 275, The gear 280 is rotated.

The second sun gear 230 which is in contact with the second planetary gear 280 is rotated and the output shaft 240 formed by extending from the second sun gear 230 rotates, Pinion mechanism portion 121. The rack-and-pinion mechanism portion 121 of the rack-and-

However, the above process is performed when the first motor 111 is not operated, and when the first motor 111 is operated, the following changes occur.

An electric signal is generated from the vehicle speed sensor 117 for sensing the speed of the vehicle, the input angle sensor 107 and the output angle sensor 115 for sensing a change in the steering angle, and the first motor position sensor 113, The electronic control unit 125 transmits an electrical signal to the first motor 111 to drive the first motor 111. [

As the first motor 111 is driven by the above process, the worm 260 connected to the motor shaft (not shown) also rotates and is thereby engaged with the worm 260, And the carrier 290, which is integrally formed with the worm wheel 250, rotates, so that the ratio of the output angle to the input angle can be adjusted.

In the active front wheel steering apparatus of an automobile, when the automobile travels at a high speed, the driver operates the steering wheel 101 in one direction so that the input shaft 210, the first sun gear 220, and the first planetary gear 270 The electronic control unit 125 causes the worm wheel 250 and further the carrier 290 to rotate in the direction that interferes with rotation of the second planetary gear 280 connected to the first planetary gear 270 The first motor 111 is controlled so that the rotation angle of the output shaft 240 is smaller than the rotation angle of the input shaft 210 to assist in safe operation.

On the other hand, when the vehicle is in a low-speed state for parking, the active front wheel steering apparatus of the automobile is operated in such a direction that the rotational angle of the output shaft 240 is larger than the rotational angle of the input shaft 210 By controlling the first motor 111, the driver can easily operate with a smaller force.

However, in such a conventional gear ratio conversion apparatus, there is a problem that precise steering control is difficult due to backlash caused by abrasion of the gear teeth. Particularly, in a steering apparatus of an automobile, noise caused by backlash causes discomfort when steering, There has been a problem that the noise is gradually increased as it proceeds.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned background, and it is an object of the present invention to provide a planetary gear mechanism that compensates for clearance between planetary gears and sun gears by applying elastic force in a radial direction to any one of connection shafts connecting input planetary gears and output planetary gears. And to provide a planetary gear device capable of preventing noise from occurring.

The objects of the present invention are not limited thereto, and other objects not mentioned may be clearly understood by those skilled in the art from the following description.

According to an embodiment of the present invention, there is provided an input device comprising: an input sun gear rotating in conjunction with an input shaft; An output line gear that rotates in conjunction with an output shaft; A plurality of input planet gears circumscribing input line gears; A plurality of output planetary gears connected to the respective input planet gears via connection shafts and circumscribing output linear gears; A bearing case through which one of the connection shafts is inserted and rotatably engaged; A carrier formed with a coupling hole through which a bearing case is inserted and is rotatably coupled with the remainder of the coupling shaft penetratingly connected to the bearing case; And an elastic support for providing an elastic force in the radial direction to the bearing case.

According to an embodiment of the present invention, elastic force is applied to one of connection shafts connecting the input planetary gears and the output planetary gears in the radial direction to compensate the clearance between the planetary gears and the sun gears, There is an effect that the occurrence can be prevented.

1 is a configuration diagram of an active front wheel barrel apparatus of a conventional automobile.
2 is a cross-sectional view schematically showing a gear ratio converting apparatus of an active front wheel steering apparatus of a conventional automobile.
3 is a perspective view of a planetary gear device according to an embodiment of the present invention.
4 is a partially exploded perspective view of the planetary gear set of Fig.
5 is a perspective view of a planetary gear device according to another embodiment of the present invention.
6 is a partially exploded perspective view of the planetary gear set of Fig.
7 is a partially exploded perspective view of a planetary gear device according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In describing the components of the present invention, the terms first, second, A, B, (a), (b), and the like can be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

2 is a cross-sectional view schematically showing a gear ratio converting apparatus of an active front wheel steering apparatus of a conventional automobile. 3 is a perspective view of a planetary gear device according to an embodiment of the present invention. 4 is a partially exploded perspective view of the planetary gear set of Fig. 5 is a perspective view of a planetary gear device according to another embodiment of the present invention. 6 is a partially exploded perspective view of the planetary gear set of Fig. 7 is a partially exploded perspective view of a planetary gear device according to another embodiment of the present invention.

1, a planetary gear set 300 according to an embodiment of the present invention includes an input sun gear 411 that rotates in conjunction with an input shaft 311; An output sun gear 331 that rotates in conjunction with the output shaft 333; A plurality of input planet gears 351 that are external to the input line gear 411; A plurality of output planetary gears 371 connected to each of the input planetary gears 351 via connection shafts and external to the output sun gear 331; A bearing case (320) through which one of the connection shafts is inserted and rotatably coupled; A carrier 390 formed with a coupling hole 391 through which the bearing case 320 is inserted and which is rotatably coupled with the remainder of the coupling shaft 431 inserted through the bearing case 320; And an elastic supporter 340 that elastically urges the bearing case 320 in the radial direction.

Hereinafter, an example in which three input planetary gears 351 and three output planetary gears 371 are provided as shown in the drawings, and an example in which the planetary gear set according to the embodiments of the present invention is used in an active front wheel steering apparatus As shown in FIG.

The input line gear 411 is provided on an input shaft 311 connected to the steering wheel 101 and rotates in conjunction with the input shaft 311. A worm wheel engaged with the worm is coupled to the input shaft 311, The input shaft 311 and the input line gear 411 interlock with each other and rotate.

The output sun gear 331 is provided on the output shaft 333 and rotates in conjunction with the output shaft 333 so that the output shaft 333 is connected to the rack-and-pinion mechanism portion 121.

The input planetary gears 351 are teeth-coupled to the input line gear 411 so that the input planetary gears 351 rotate in conjunction with rotation of the input line gear 411.

The output planetary gears 371 are tooth-coupled to circumscribe the output line gear 331. Each output planetary gear 371 is connected to the input planetary gears 351 via a connection shaft so that input planetary gears 351 The output planetary gear 371 rotates in conjunction therewith.

The bearing case 320 is rotatably coupled to one of the connection shafts 431 connecting the input planetary gears 351 and the output planetary gears 371.

That is, the bearing case 320 is formed with a through hole 421 in the axial direction so that the coupling shaft 431 is inserted into the bearing case 320. The 'axial direction' is a length of the combined input shaft 311 and the output shaft 333 Direction.

The support case 423 is formed in the bearing case 320 so as to support one end of the elastic support body 340. The support case 423 is formed in a groove- So that the elastic supporter 340 can stably provide the elastic force to the bearing case 320.

The rotation support member 450 is further coupled to the through hole 421 of the bearing case 320 so as to reduce the rotational friction between the connection shaft 431 and the connection shaft 431, For example, it can be provided as a bush bearing.

Of course, the rotation support member 450 may be coupled to the outer circumferential surface of the connection shaft 431 which is rotatably coupled through the through hole 421 of the bearing case 320, have.

The guiding end guiding portion 425 may be formed on one side or both sides in the circumferential direction of the bearing case 320. The guiding end guiding portion 425 may be formed in the coupling holes 391 and 791 of the carrier 390, As shown in FIG.

By forming the guide step portion 425 in the bearing case 320 and forming the guide step support portion 491 in the engagement holes 391 and 791 of the carrier 390, the bearing case 320 can be inserted into the engagement holes 391 and 791 ). ≪ / RTI >

The carrier 390 may be formed in a disk shape and includes a connection shaft 431 connected to the bearing case 320 among connection shafts connecting the input planetary gears 351 and the output planetary gears 371 The remaining connection axes are inserted and coupled, and the above-described bearing case 320 is inserted into the coupling hole 391 and coupled.

The guide step support portion 491 may be formed in the coupling hole 391 so that the guide step portion 425 of the bearing case 320 is supported and the bearing inserted into the coupling hole 391, Both sides in the axial direction of the case 320 can be supported by a supporting member 471 coupled to the connecting shaft 431. [

Of course, such a support member 471 may also be coupled to the connection shaft 431 shown in Figs.

7, the coupling hole 791 may be formed so that the inner circumferential surface thereof is inclined so that the circumferential width gradually decreases in the axial direction. In this case, The outer peripheral surface is formed to be inclined so as to correspond to the shape.

The outer circumferential surface of the bearing case 720 is inclined so that the inner circumferential surface of the coupling hole 791 of the carrier 390 is inclined so that the bearing case 720 can be smoothly inserted into the coupling hole 791 .

On the other hand, at the center of the carrier 390, an insertion hole 444 into which the end of the output shaft 333 is inserted is formed.

The elastic support 340 provides an elastic force in the radial direction to the bearing case 320. The elastic support 340 may be provided as a coil spring, And the other end is supported on the inner circumferential surface of the coupling hole 391, 791 of the carrier 390.

Since the elastic support body 340 provides the elastic force in the radial direction to the bearing case 320, the connection shaft 431 penetratingly coupled to the bearing case 320 receives the elastic force radially inward, And the sun gears 331 and 411 can be compensated for.

5 to 7, a cover portion 510 may be further coupled to the coupling holes 391 and 791 of the carrier 390 to prevent the bearing cases 320 and 720 from being separated from each other. The cover 510 is formed to correspond to the shape of an inlet of the coupling holes 391 and 791 into which the bearing cases 320 and 720 are inserted and the hole 611 is formed in the center of the cover portion 510, And is formed into a plate shape of a square formed.

The cover portion 510 may be press-fitted into the coupling holes 391 and 791 and the cover portion 510 may be further coupled to the coupling holes 391 and 791 of the carrier 390, The possibility of disengagement of the bearing cases 320 and 720 can be prevented.

As described above, according to the embodiments of the present invention, elastic force is applied to one of the connection shafts connecting the input planetary gears and the output planetary gears in the radial direction, So that noise can be prevented from being generated.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

300: A planetary gear device according to an embodiment of the present invention
311: Input shaft
320: Bearing case
331: Output Line Gear
333: Output shaft
340: elastic support
351: input planetary gear
371: Output planetary gear
390: Carrier
391: Coupling hole
411: input line gear
431: Connection axis

Claims (6)

An input line gear that rotates in conjunction with an input shaft;
An output line gear that rotates in conjunction with an output shaft;
A plurality of input planet gears circumscribing the input line gear;
A plurality of output planetary gears connected to each of the input planetary gears via connection shafts and circumscribing the output sun gear;
A bearing case through which one of the connection shafts is inserted and rotatably coupled;
A carrier having a coupling hole through which the bearing case is inserted and formed so as to be rotatable, the coupling shaft penetratingly connected to the bearing case; And
An elastic supporter for providing elastic force to the bearing case in a radial direction;
Wherein the planetary gear set includes: The method according to claim 1,
Wherein the bearing case is formed with a support groove for supporting one end of the elastic supporter in the radial direction. 3. The method of claim 2,
Wherein the engaging hole is formed so that its inner circumferential surface is inclined so that the circumferential width gradually decreases in the axial direction,
Wherein the bearing case has an outer circumferential surface inclined so as to correspond to the engagement hole. 4. The method according to any one of claims 1 to 3,
A guide step protruding from one side or both sides of the bearing case in the circumferential direction,
Wherein the engagement hole is formed with a guide step support portion for supporting the guide step portion. 5. The method of claim 4,
Further comprising a cover portion coupled to the coupling hole to prevent the bearing case from being disengaged. 6. The method of claim 5,
Further comprising a rotation support member coupled to an outer circumferential surface of the connection shaft so as to reduce a rotational friction force of the connection shaft coupled to the bearing case.

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