JP2006275274A - Rotating gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the overall size of a rotary transmission device including a differential mechanism and first and second electric motors, to improve the mountability to a vehicle, and to further increase the transmission efficiency of the rotational force of the electric motor. Provided is a rotary transmission device that can
SOLUTION: A first sun gear 3 connected so that a first shaft 1 is rotated in conjunction with it, a second sun gear 4 connected so that a second shaft 2 is rotated in conjunction with each other, A first planetary gear 5 that meshes with the first sun gear 3, a second planetary gear 6 that rotates integrally with the first planetary gear 5, and meshes with the second sun gear 4; A carrier 7 that supports the planetary gears 5 and 6, a first electric motor 11 that rotates the carrier 7, and a second that applies a required torque to the first shaft in response to a torque applied to the second shaft. The first and second electric motors 11 and 14 include an electric motor 14, and the output shafts 11 a and 14 a of the first and second electric motors 11 and 14 are the same as the first shaft 1 and the second shaft 2. They were arranged in parallel.
[Selection] Figure 1

Description

  The present invention relates to a differential mechanism that links a first shaft and a second shaft, which are arranged freely to rotate, to rotate in conjunction with each other, and a link to rotate in conjunction with the second shaft of the differential mechanism. The present invention relates to a rotation transmission device including an electric motor that rotates a rotating member that is rotated.

  A rotary transmission device having a differential mechanism is used in a vehicle steering device. The rotational transmission device for a steering device includes a sun gear having a first shaft connected to a steering wheel, a planetary gear that rotates while revolving around the sun gear, and a sun gear coaxially with the first shaft. A carrier that supports the planetary gear, an internal gear that meshes with the planetary gear, a worm that meshes with a transmission gear provided on the outer periphery of the internal gear, and the worm A differential electric motor having an output shaft coupled so as to rotate in conjunction with the motor, and driving the differential electric motor based on a steering angle and a vehicle speed of the steering wheel. The carrier is rotated via a gear and a planetary gear to increase the speed of the second shaft relative to the first shaft (for example, Patent Document 1).

Further, as a vehicle steering apparatus including a differential mechanism and a differential first electric motor, a worm wheel is provided on a first shaft connected to the steering wheel, and the worm meshes with the worm wheel and the worm. There is also known a steering apparatus that includes a second electric motor that has an output shaft connected to rotate in conjunction with the second shaft and applies a required torque to the first shaft in response to a torque applied to the second shaft. . The second electric motor is driven when the steering torque applied to the first shaft changes from the appropriate steering torque, such as when the second shaft is rotated at an increased speed by the first electric motor, and is applied to the second shaft. A required torque is applied to the first shaft in accordance with the torque, and the torque is corrected so as to obtain an appropriate steering torque.
JP 2003-31486 A

  However, in the rotary transmission device including the differential mechanism and the first and second electric motors, the rotational force of the first electric motor is transmitted to the second shaft through the worm and the transmission gear, Since the rotational force of the electric motor is transmitted to the first shaft via the worm and the worm wheel, the first and second electric motors are orthogonal to the axis of the first shaft and the second shaft. Therefore, the first and second electric motors largely project outward with respect to the differential mechanism, so that the entire rotation transmission device becomes large and can be mounted on a vehicle. It would have been a hindrance and there was a need for improvement. In addition, since the tooth trace of the worm has a spiral shape, there is a problem that the frictional resistance of the meshing portion is relatively large and the transmission efficiency of the rotational force of the electric motor is impaired.

  The present invention has been made in view of such circumstances, and a main object of the present invention is to reduce the overall size of the rotary transmission device including the differential mechanism and the first and second electric motors, and to improve the mountability to the vehicle. In addition, another object of the present invention is to provide a rotation transmission device that can increase the transmission efficiency of the rotational force of the electric motor.

  A rotation transmission device according to a first aspect of the present invention is a differential mechanism that connects a first shaft and a second shaft that are arranged to rotate freely so as to rotate in conjunction with each other, and is linked to the second shaft of the differential mechanism. And a first electric motor that rotates a rotating member that is coupled so as to rotate. A second transmission that applies a required torque to the first shaft in response to a torque applied to the second shaft. An electric motor is provided, and the first and second electric motors are arranged such that output shafts of the respective electric motors are parallel to the first axis and the second axis. .

  According to a second aspect of the present invention, in the first aspect of the present invention, the first transmission vehicle pair that transmits the rotational force of the first electric motor to the rotating member and the rotational force of the second electric motor are And a second transmission vehicle pair that is transmitted to the first shaft, wherein the first and second transmission vehicle pairs are juxtaposed.

  According to a third aspect of the present invention, in the first or second aspect, the differential mechanism includes a first sun gear coupled so that the first shaft rotates in conjunction with the second shaft, and the second gear. A second sun gear coupled so as to rotate in association with the shaft; a first planetary gear meshing with the first sun gear; and the second planetary gear rotating integrally with the first planetary gear; A second planetary gear that meshes with the sun gear, and a carrier that supports the first and second planetary gears and that is rotated by the first electric motor. The transmission vehicle pair has one transmission vehicle on one side in the central axis direction, and a bearing is fitted on the other side in the central axis direction.

  In the first invention, since the output shafts of the first and second electric motors are arranged in parallel with the first shaft and the second shaft, the differential mechanism of the first and second electric motors The amount of protrusion can be reduced, the entire rotation transmission device can be reduced in size, and the mountability to the vehicle can be improved. Further, since the output shaft is parallel to the first shaft and the second shaft, a spur gear can be used as a transmission vehicle pair that transmits the rotational force of the electric motor to the first shaft and the second shaft. The frictional resistance of the pair of meshing portions can be reduced, and the transmission efficiency of the rotational force of the electric motor can be increased.

  In the second aspect of the invention, the first transmission vehicle pair for transmitting the rotational force of the first electric motor to the rotating member of the differential mechanism, and the first for transmitting the rotational force of the second electric motor to the first shaft. Since the two transmission vehicle pairs are juxtaposed, the circumference of the transmission vehicle pair can be reduced in size, the entire rotary transmission device can be further reduced in size and weight, and the cost can be reduced. Can be

  In the third invention, one transmission vehicle of the first transmission vehicle pair is provided on one side in the central axis direction of the carrier, and the bearing is externally fitted on the other side in the central axis direction. The carrier can be supported in a cantilever manner by this bearing, the length of the differential mechanism in the axial length direction of the first shaft can be shortened, and the rotational transmission device can be further reduced in size.

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof.
Embodiment 1
FIG. 1 is a cross-sectional view showing a configuration of a first embodiment of a rotary transmission device according to the present invention, FIG. 2 is an enlarged cross-sectional view of a main part, and FIG.

  This rotation transmission device includes a first shaft 1 and a second shaft 2 that are arranged so as to freely rotate on the same axis, and a first sun gear that is connected so that the first shaft 1 rotates on the same axis. 3, a second sun gear 4 that is connected so that the second shaft 2 rotates coaxially, a plurality of first planetary gears 5 that mesh with the first sun gear 3, A second planetary gear 6 that rotates integrally with the first planetary gear 5 coaxially and meshes with the second sun gear 4, and a carrier as a rotating member that supports the first and second planetary gears 5, 6. 7, a first transmission gear 8 provided on the outer periphery of the carrier 7, and a second transmission gear 10 that meshes with the teeth of the first transmission gear 8. The first electric motor 11 that rotates the motor 7, the third transmission gear 12 that is provided in the middle of the first shaft 1, and the third transmission gear 12 For the reaction force that has the fourth transmission gear 13 to be combined and applies the required torque to the first shaft 1 according to the torque applied to the second shaft 2, in other words, the torque applied to the first shaft 1 is appropriate. A second electric motor 14 is provided that provides the first shaft 1 with a reaction torque in the same direction as the torque applied to the first shaft 1 when changing from the torque.

  A first sun gear 3 is integrally provided at one end of the first shaft 1, and a second sun gear 4 is integrally provided at one end of the second shaft 2. Two sun gears 3 and 4 face each other on the same axis. The second shaft 2 is rotatably accommodated and supported in the housing 9 via the first bearing 15, and the first shaft 1 is rotatably accommodated and supported in the housing 9 via the second bearing 16.

  A ball bearing 17 and a needle roller bearing 18 are fitted on the second shaft 2 between the second sun gear 4 and the first bearing 15, and a nut 19 is interposed between the first bearing 15 and the ball bearing 17. It is screwed.

  The first shaft 1 is integrally provided with a third transmission gear 12 formed of a spur gear in the middle, and the vicinity of the third transmission gear 12 is supported in the housing 9 via a second bearing 16. The needle roller bearing 20 for supporting the carrier 7 and the angular ball bearing for receiving the thrust load applied to the carrier 7 are provided between the first sun gear 3 and the third transmission gear 12. The third bearing 21 is fitted. Further, a torque sensor (not shown) for detecting torque applied to the first shaft 1 is provided around the outer periphery of the first shaft 1, and the first sensor 1 is based on the torque detected by the torque sensor. A control unit 22 that controls the drive circuits 11a and 14a of the first and second electric motors 11 and 14 is provided.

  The first and second planetary gears 5 and 6 are integrally formed on the same axis, and a shaft body 5a is fitted into a through-hole penetrating the center portion, and both end portions of the shaft body 5a are connected to a needle. It is rotatably supported on the carrier 7 via the roller bearings 23 and 24.

  The carrier 7 includes an annular first plate portion 7 a that is rotatably fitted and supported on the outer peripheral portion of the first shaft 1 via a needle roller bearing 20, and the second shaft 2 via a needle roller bearing 18. An annular second plate portion 7b that is rotatably fitted and supported on the outer peripheral portion, and a connecting member (not shown) that connects a plurality of locations on the outer peripheral portion of the first plate portion 7a and the second plate portion 7b; It has a cylindrical portion 7c that is connected to the outer peripheral portion of the first plate portion 7a and is arranged outside the first planetary gear 5. Further, an annular first transmission gear 8 made of a spur gear is integrally provided on the outer peripheral portion of the first plate portion 7a on one side in the central axis direction, and on the other side in the central axis direction. A fourth bearing 26 made of a needle roller bearing is fitted on the cylindrical portion, and a needle roller bearing 27 is fitted on the outer periphery of the second plate portion 7b. The carrier 7 is cantilevered by a needle roller bearing 27 and is rotatably supported in the housing 9. Moreover, the annular convex part 7d which protrudes outside is integrally provided in the inner peripheral part of the 1st board part 7a.

  The housing 9 includes a small-diameter cylindrical portion 91a in which the second shaft 2 is accommodated and supported, a medium-diameter cylindrical portion 91b in which the carrier 7 is accommodated and supported, and a large-diameter cylindrical portion in which the second and fourth transmission gears 10 and 13 are accommodated. A first cylinder 91 having 91c, a second cylinder 92 in which the first shaft 1 and the torque sensor are accommodated and supported, a third cylinder 93 in which one end of the second cylinder 92 is accommodated, An annular connecting plate 94 that connects the first cylindrical body 91 and the third cylindrical body 93.

  An outer ring of the first bearing 15 is loosely fitted inside the small-diameter cylindrical portion 91a, and a female screw 9a is provided at the opening end, and the female screw 9a is in contact with the outer ring of the first bearing 15, A screw ring 28 as a pressurizing body that pressurizes the outer ring in the center line direction is screwed. A needle roller bearing 27 is fitted inside the middle diameter cylindrical portion 91b. Two bearing holes 9c, 9d spaced parallel to the first shaft 1 and the bearing hole 9c are provided at two positions spaced apart in the circumferential direction between the middle diameter cylindrical portion 91b and the large diameter cylindrical portion 91c. , 9d, bearings 29, 30 are provided.

  One end of the second cylinder 92 is fitted and held inside the connecting plate 94, and the first shaft 1 is supported on the inside via the second bearing 16 and a needle roller bearing (not shown).

The output shafts 11b and 14b of the differential and reaction force electric motors 11 and 14 are spaced in parallel with the first shaft 1 at two locations separated in the circumferential direction of the third cylinder 93 and the connecting plate 94. Are inserted through holes 9e, 9e, 9f, and 9f, and the bearings 31 and 32 are fitted into the insertion holes 9f and 9f of the connecting plate 94. The bearings 29 and 31 allow the output shaft 11b to The first shaft 1 and the second shaft 2 are supported in parallel, and the output shaft 14 b is supported by the bearings 30 and 32 in parallel with the first shaft 1 and the second shaft 2.
A second transmission gear 10 made of a spur gear is integrally provided in the middle of the output shaft 11b, and a fourth transmission gear 13 made of a spur gear is integrally provided in the middle of the output shaft 14b. A motor case for the electric motors 11 and 14 is attached to the end of the third cylinder 93.

  The first transmission vehicle pair composed of the first and second transmission gears 8 and 10 and the second transmission vehicle pair composed of the third and fourth transmission gears 12 and 13 are arranged around the outer periphery of the first shaft 1. They are juxtaposed across a gap allowing relative rotation.

  In the rotational transmission device configured as described above, when the screw ring 28 screwed to the housing 9 is operated to rotate, the operating force of the screw ring 28 causes the outer ring, ball, inner ring, and nut 19 of the first bearing 15 to operate. , Through the inner ring of the ball bearing 17, the ball, the outer ring, the carrier 7, the annular projection 7 d, the outer ring of the third bearing 21, the ball, the inner ring, the first shaft 1, the inner ring of the second bearing 16, the ball and the second through the outer ring. It can be added to the cylindrical body 92 and has a play at the rotating portion. Specifically, the first shaft 1, the second shaft 2, the carrier 7, the first bearing 15, the ball bearing 17, the second bearing 16, and the third bearing 21. Can be eliminated. After eliminating the rattling at the rotating portion in this way, the rotation of the screw ring 28 can be locked by screwing the lock nut 33 onto the screw ring 28, and the state without rattling can be maintained. it can.

  The rotation transmission device configured as described above is mainly used in a vehicle steering device. In this steering apparatus, a steering wheel is coupled to a first shaft 1, a second shaft 2 has a pinion and rack teeth meshing with the pinion, and a steered shaft capable of moving in the axial length direction thereof. The pinion of the steering mechanism provided with is connected so as to rotate in conjunction with each other, and the pinion is rotated by operating a steering wheel to rotate the steered wheels supported at both ends of the steered shaft. It is configured so that it can be steered.

  The steering device configured as described above passes through the first sun gear 3, the first and second planetary gears 5 and 6, and the second sun gear 4 when the steering wheel rotates the first shaft 1. The second shaft 2 rotates at the same speed as the first shaft 1. Further, when the differential electric motor 11 is driven by a command signal output from the control unit 23 to the drive circuit 11 a, the carrier 7 rotates through the second transmission gear 10 and the first transmission gear 8. The second shaft 2 rotates at a higher speed through the first and second planetary gears 5 and 6 and the second sun gear 4. When the steering torque applied to the first shaft 1 changes from the appropriate torque due to the accelerated rotation of the second shaft 2, a command signal output from the control unit 22 to the drive circuit 14a according to the torque applied to the second shaft 2 and the like. Accordingly, the reaction force electric motor 14 is driven, for example, reaction force torque in the same direction as the rotation direction of the first shaft 1 is applied to the first shaft 1, and the steering torque applied to the first shaft 1 is maintained at an appropriate value. can do.

Embodiment 2
FIG. 4 is a schematic diagram showing the configuration of the second embodiment of the rotational transmission device according to the present invention. This rotation transmission device is a differential mechanism B that does not use gears, instead of the differential mechanism A having sun gears 3 and 4 and planetary gears 5 and 6. This rotational transmission device includes first and second sun wheels 34 and 35 corresponding to the first and second sun gears 3 and 4, and first and second sun gears 5 and 6 corresponding to the first and second planetary gears 5 and 6. The second planetary wheels 36, 37, the first sun wheel 34 and the first transmission belt 38 hung on the first planetary wheel 36, the second sun wheel 35 and the second planetary wheel 37 A differential mechanism B having a second transmission band 39 suspended and a carrier 7 that rotatably supports the first and second planetary wheels 36 and 37, and the first transmission wheel pair. The differential electric motor 11 that rotates the carrier 7 and the first shaft 1 are driven when the steering torque applied to the first shaft 1 changes from the appropriate steering torque. And an electric motor 14 for reaction force that applies torque.

  In the second embodiment, the first shaft 1 is connected to the first sun wheel 34 so as to rotate coaxially and the second shaft 2 is coaxially connected to the second sun wheel 35. It is connected to rotate in conjunction. The first and second planetary wheels 36 and 37 are integrally formed on the same axis.

  The output shafts 11a and 14a are supported in parallel with the first shaft 1 and the second shaft 2, and the first transmission vehicle pair including the first and second transmission gears 8 and 10; The second transmission wheel pair composed of the third and fourth transmission gears 12 and 13 is juxtaposed around the outer periphery of the first shaft 1 with a clearance allowing relative rotation.

In the second embodiment, by rotating the first shaft 1, the second shaft 2 passes through the first sun wheel 34, the first and second planetary wheels 36 and 37, and the second sun wheel 35. Rotates at the same speed as the first shaft 1. Further, when the first electric motor 11 is driven by a command signal output from the control unit 22 to the drive circuit 11a, the carrier 7 rotates through the second transmission gear 10 and the first transmission gear 8, The second shaft 2 rotates at an increased speed through the first and second planetary wheels 36 and 37 and the second sun wheel 35. When the steering torque applied to the first shaft 1 changes from the appropriate steering torque due to the accelerated rotation of the second shaft 2, a command output from the control unit 22 to the drive circuit 14a according to the torque applied to the second shaft 2 and the like. The second electric motor 14 is driven by the signal, and for example, a reaction torque in the same direction as the rotation direction of the first shaft 1 is applied to the first shaft 1, and the steering torque applied to the first shaft 1 is maintained at an appropriate value. can do.
Since other configurations and operations are the same as those of the first embodiment, the same components are denoted by the same reference numerals, and detailed description thereof and description of operations and effects are omitted.

  5, 6, 7 and 8 are schematic views showing the layouts of the first and second electric motors of the rotational transmission device according to the present invention. As described above, the first and second electric motors 11 and 14 described above are provided around the first shaft 1 at positions equally distributed in the circumferential direction of the first shaft 1 as shown in FIG. However, the positions of the first and second electric motors 11 and 14 with respect to the first shaft 1 and the second shaft 2 are not particularly limited. For example, as shown in FIG. 6, the first electric motor 11 is arranged around the first shaft 1, and the second electric motor 14 is turned around the second shaft 2 and relative to the output shaft of the electric motor 11. The first electric motor 11 may be arranged around the first shaft 1 and the second electric motor 14 may be disposed on the second shaft as shown in FIG. 2 and at a position that is coaxial with the output shaft of the electric motor 11, and the first and second electric motors 11 and 14 are connected to the second shaft as shown in FIG. It is good also as a structure provided with the suitable phase difference around 2.

  In the first embodiment, the first electric motor 11 rotates the carrier 7. However, for example, the first electric motor 11 may rotate the second shaft 2 directly.

In the embodiment described above, spur gears are used as the first to fourth transmission gears 8, 10, 12, and 13. However, helical gears and helical gears may also be used. The tooth profile is not particularly limited as long as the central axis of the gear connected to rotate in conjunction with the output shaft of the motors 11 and 14 and the output shaft are parallel to the first shaft 1 and the second shaft 2. .
In the second embodiment, a flat belt is used as the transmission band, but a V belt or a toothed belt may also be used.

It is sectional drawing which shows the structure of Embodiment 1 of the rotational transmission apparatus which concerns on this invention. It is an expanded sectional view of the principal part. It is sectional drawing of the III-III line | wire of FIG. It is a schematic diagram which shows the structure of Embodiment 2 of the rotational transmission apparatus which concerns on this invention. It is a schematic diagram which shows the layout of the 1st and 2nd electric motor of the rotational transmission apparatus which concerns on this invention, (a) is a front view, (b) is a side view. It is a schematic diagram which shows the layout of the 1st and 2nd electric motor of the rotational transmission apparatus which concerns on this invention, (a) is a front view, (b) is a side view. It is a schematic diagram which shows the layout of the 1st and 2nd electric motor of the rotational transmission apparatus which concerns on this invention, (a) is a front view, (b) is a side view. It is a schematic diagram which shows the layout of the 1st and 2nd electric motor of the rotational transmission apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st axis | shaft 2 2nd axis | shaft 3 1st sun gear 4 2nd sun gear 5 1st planetary gear 6 2nd planetary gear 7 Carrier (rotating member)
8 First transmission gear (first transmission vehicle pair)
10 Second transmission gear (first transmission vehicle pair)
11 First electric motor 11a Output shaft 12 Third transmission gear (second transmission vehicle pair)
13 Fourth transmission gear (second transmission vehicle pair)
14 Second electric motor 14a Output shaft 15 Sun gear 16 Internal gear 17 Planetary gear 18 Carrier 26 Fourth bearing (bearing)
27 Needle roller bearing (bearing)
34 first solar wheel 35 second solar wheel 36 first planetary wheel 37 second planetary wheel A, B differential mechanism

Claims (3)

  A differential mechanism that connects the first shaft and the second shaft, which are arranged to rotate freely, to rotate in conjunction with each other, and a rotation that is connected to rotate in conjunction with the second shaft of the differential mechanism. A rotation transmission device including a first electric motor for rotating a member, the rotation transmission device including a second electric motor for applying a required torque to the first shaft in response to a torque applied to the second shaft; And the second electric motor is arranged such that an output shaft of each electric motor is parallel to the first shaft and the second shaft.   A first transmission vehicle pair that transmits the rotational force of the first electric motor to the rotating member; and a second transmission vehicle pair that transmits the rotational force of the second electric motor to the first shaft. The rotary transmission device according to claim 1, wherein the first and second transmission vehicle pairs are juxtaposed. The differential mechanism includes a first sun gear coupled so that the first shaft rotates in conjunction with the second sun gear coupled so that the second shaft rotates in conjunction with each other, A first planetary gear meshing with the first sun gear; a second planetary gear rotating integrally with the first planetary gear and meshing with the second sun gear; and the first and second And a carrier that is rotated by the first electric motor, and the carrier has one transmission vehicle of the first transmission vehicle pair on one side in the central axis direction. The rotation transmission device according to claim 1, wherein a bearing is fitted on the other side in the central axial direction.

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