JP2006226375A - Rotary transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary transmission mechanism capable of reducing impact noise generated by impact of teeth of each gear at a meshing part of gears and sliding noise generated with accompanying action of the gear, miniaturizing a device, and reducing number of parts and assembly man-hour. <P>SOLUTION: This device is provided with a first sun gear 2, a second sun gear 23, first planetary gears 24, 24 and second planetary gears 25, 25. Number of meshing part is reduced by integrating a carrier 26 supporting each planetary gear with a rotor of a speed change motor 27 for changing speed of transmitted rotation. The rotor is formed in a cylinder shape, and an input shaft 4a rotating the first sun gear 22 is inserted through the rotor to effectively use limited space. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention can perform transmission of rotation from the input side to the output side in a stepless manner by changing the transmission ratio. For example, in a vehicle steering device, the operation amount of the steering member and the operation amount of the steering mechanism The present invention relates to a rotary transmission device used for changing a correspondence relationship.

  Steering of the vehicle is performed by transmitting a rotation operation applied to the steering member to the steering mechanism via the column shaft, converting the vehicle into a linear motion in the left-right direction of the vehicle, and changing the direction of the wheels. . When performing such steering, for example, when the traveling speed of the vehicle is low, the steering operation amount of the wheel is increased with respect to the rotational operation amount of the steering member, and conversely when the traveling speed of the vehicle is high. By reducing the amount of steering movement of the wheel relative to the amount of rotational operation of the steering member, it is possible to facilitate the driving operation during low-speed traveling and increase the stability during high-speed traveling.

  For this reason, a rotation transmission device that transmits the rotation by changing the transmission ratio is arranged in the middle part of the column shaft that connects the steering member and the steering mechanism, and the steering member side that is the output side from the steering member side that is the input side A steering device that can transmit rotation to the mechanism side by changing a transmission ratio has been put into practical use. As a rotational transmission device, for example, a planetary gear mechanism and a motor for changing the rotational speed, which can change the transmission ratio steplessly, have been put into practical use.

  In Patent Document 1, a planetary gear mechanism including a sun gear, a planetary gear, and an internal gear is used, the input shaft is fixed to the sun gear, the output shaft is fixed to the carrier that connects the rotation shaft of the planetary gear, and the internal gear is There has been proposed a steering apparatus that includes a motor to be rotated and that can change a transmission ratio of rotation from an input shaft to an output shaft by controlling the rotation speed of an internal gear. In this steering device, when the internal gear is rotated in the same direction as the rotation direction of the input shaft by the motor, the rotation speed of the output shaft can be increased according to the rotation speed of the internal gear, When the internal gear is rotated in the direction opposite to the input shaft, the rotational speed of the output shaft can be reduced according to the rotational speed of the internal gear.

In Patent Document 2, the first internal gear that rotates integrally with the steering member, the first sun gear, the first planetary gear that meshes with the first internal gear and the first sun gear, and the output shaft rotate integrally. A second planetary gear meshing with the second internal gear, the second sun gear, and the second internal gear and the second sun gear, wherein the first sun gear and the second sun gear are integrally rotated by a motor; Thus, there has been proposed a steering device that can change the transmission ratio of rotation. In this steering apparatus, the rotation of the first internal gear is transmitted to the second internal gear through the rotation and revolution of the first planetary gear and the second planetary gear. , The rotational speed of the second internal gear can be increased according to the rotational speed of the sun gear, and the sun gear can be rotated in the opposite direction to the first internal gear. When the second internal gear is rotated, the rotational speed of the second internal gear can be reduced.
Japanese Utility Model Publication No.6-2860 JP 2002-240730 A

  However, in the vehicle steering device, each time the traveling direction of the vehicle is changed, the rotation direction of the steering member and the column shaft is switched, so that when the planetary gear mechanism is used for the steering device, There is a problem that abnormal noise is generated at the meshing portion of the gear. This abnormal noise is a collision sound generated when the gear teeth move relative to each other within the backlash range and collide with each other when the rotation direction is switched. In addition, a sliding noise accompanying the operation of the gear is also generated.

  In the steering apparatus described in Patent Literature 1 and Patent Literature 2, teeth of each gear collide at the meshing portion of the sun gear and the planetary gear and the meshing portion of the planetary gear and the internal gear, and noise is generated. In addition, since the sun gear, the planetary gear, and the internal gear are meshed with each other, there is a problem that the planetary gear mechanism is increased in size, resulting in an increase in the number of parts and an increase in the number of assembly steps. . Further, in the steering device described in Patent Document 1, since another gear mechanism is used for transmitting the rotation of the motor, there is a problem that abnormal noise is generated even at the meshing portion of the gear mechanism.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a first transmission gear, a first planetary gear, a second planetary gear, and a second planetary gear in a rotational transmission device using a planetary gear mechanism. Two sun gears are provided, the carrier supporting each planetary gear and the rotor of the motor are integrated, and the rotation speed of the carrier is controlled to transmit the rotation. Since only the meshing part of the planetary gear is used, the collision noise of the gear can be reduced, the sliding noise accompanying the operation of the gear can be reduced, the number of parts and the number of assembly steps can be reduced, and the device Is to provide a rotary transmission device that can be reduced in size.

  A rotational transmission device according to a first aspect of the present invention includes a first sun gear, a second sun gear supported coaxially with the first sun gear, a first planetary gear meshing with the first sun gear, A second planetary gear meshing with the second sun gear and rotating together with the first planetary gear; and the first planetary gear and the second planetary gear supported rotatably about their respective axes; And a rotation transmission device comprising a carrier that rotates coaxially with the second sun gear and a motor that changes the rotational speed of rotation transmitted by each gear, the motor being coaxial with the first sun gear and the second sun gear. The rotor of the motor and the carrier are integrated.

  In the rotation transmission device according to the second aspect of the present invention, the rotor has a cylindrical shape, and an input shaft that rotates integrally with the first sun gear or an output shaft that rotates integrally with the second sun gear includes the rotor. And the carrier and the rotor are disposed so as to be rotatable relative to the input shaft or the output shaft.

  In the rotation transmission device according to the first aspect of the present invention, the first planetary gear rotates due to the rotation applied to the first sun gear, the second planetary gear rotates accompanying the rotation of the first planetary gear, and the second As the second sun gear rotates due to the rotation of the planetary gear, rotation is transmitted from the first sun gear to the second sun gear. At this time, when the carrier is rotated in the same (reverse) direction as the rotation of the first sun gear by the motor integrated with the carrier, each planetary gear together with the carrier is in the same (reverse) direction as the first sun gear. Since the rotation of the second sun gear can be increased (decreased) by the revolution speed of the second planetary gear, the rotation direction and the rotation speed of the motor are controlled to move from the input side to the output side. Rotation can be transmitted by changing the transmission ratio steplessly. In addition, since the meshing portion of the gear is only the meshing portion of the sun gear and the planetary gear, it is possible to reduce the generated noise, and quiet operation is possible, and the number of parts and assembly man-hours can be reduced. Costs associated with the manufacture of the rotary transmission device can be reduced.

  Further, in the rotational transmission device according to the second invention, the rotor of the motor is cylindrical, and the input shaft that rotates integrally with the first sun gear or the output shaft that rotates integrally with the second sun gear passes through the rotor. By doing so, the limited space can be used effectively, and the apparatus can be miniaturized.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof. FIG. 1 is a schematic diagram showing an application example of a rotation transmission device according to the present invention in a vehicle steering device. In the figure, reference numeral 1 denotes a rack and pinion type steering device, which includes a rack shaft 10 that is supported so as to be movable in the axial direction within a cylindrical rack housing 9 that extends in the left-right direction of the vehicle body. Tie rods 11, 11 are connected to both ends of the rack shaft 10 protruding from both sides of the rack housing 9, and the opposite side ends of the connecting portions of the tie rods 11, 11 to the rack shaft 10 are different knuckle. Steering wheels 13 and 13 are connected via the arms 12 and 12. As the rack shaft 10 moves in the axial direction, the knuckle arms 12 and 12 are pushed and pulled through the tie rods 11 and 11 to steer the wheels 13 and 13 to the left and right.

  Near one end of the rack housing 9 is a cylindrical pinion housing 8 that intersects with the rack housing 9, and inside the pinion housing 8 is rotatable about an axis. A pinion shaft 7 is supported. A pinion (not shown) is integrally formed below the pinion shaft 7, and meshes with a rack tooth (not shown) formed at a corresponding portion of the rack shaft 10 at the intersection with the rack housing 9.

  The column shaft 4 is connected to the upper end portion of the pinion shaft 7 protruding from the upper portion of the pinion housing 8 via the intermediate shaft 6. The column shaft 4 is supported inside a column housing 5 that is fixed and supported at an appropriate part of the vehicle body so as to be rotatable around the shaft. The column shaft 4 is divided into an input shaft 4a and an output shaft 4b inside the column housing 5 (see FIG. 2), and the steering member 2 is attached to the input shaft 4a protruding from the upper end of the column housing 5. An intermediate shaft 6 is connected to the output shaft 4b that is connected and protrudes from the lower end.

  In the lower part of the column housing 5, the rotation of the present invention is performed in a gear housing 21 formed by expanding the diameter of the column housing 5, in which the transmission of rotation from the input shaft 4 a to the output shaft 4 b is steplessly changed. A transmission device is provided, and a steering angle sensor 14 for detecting the rotation angle of the steering member 2 is disposed at the top of the column housing 5. Further, a reaction force motor 18 for generating an additional torque for changing the operation torque of the steering member 2 is disposed outside the column housing 5 in the vicinity of the upper end portion of the gear housing 21. The driver can obtain a good steering feeling due to the additional torque generated by 18.

  The rotational transmission device in the gear housing 21 includes a speed change motor 27 (see FIG. 2) for changing the transmission ratio. The speed change motor 27 and the reaction force motor 18 are respectively driven by a drive circuit 17a and a drive circuit 17b. Driven by rotation. The control unit 15 that controls the operation of the drive circuit 17a and the drive circuit 17b is given the rotation angle of the steering member 2 detected by the steering angle sensor 14 and the traveling speed of the vehicle detected by the vehicle speed sensor 16, and the detection results thereof. The control unit 15 gives a drive command to the drive circuit 17a and the drive circuit 17b so as to rotate the speed change motor 27 and the reaction force motor 18 at a rotation direction and a rotation speed according to the above.

  FIG. 2 is a longitudinal sectional view showing the configuration of the rotational transmission device according to the present invention. The input shaft 4a and the output shaft 4b constituting the column shaft 4 are arranged inside the gear housing 21 with the lower end of the input shaft 4a and the upper end of the output shaft 4b facing each other. A first sun gear 22 is integrally formed at the lower end portion of the input shaft 4a, and a second sun gear 23 is integrally formed at the upper end portion of the output shaft 4b. The input shaft 4a, the first sun gear 22, the second sun gear 23, and the output shaft 4b rotate coaxially.

  Two first planetary gears 24, 24 are meshed with the outer peripheral teeth of the first sun gear 22, and two second planetary gears 25 are engaged with the outer peripheral teeth of the second sun gear 23. , 25 are meshed. The first planetary gears 24, 24 and the second planetary gears 25, 25 are connected and fixed to the support shafts 29, 29 so as to rotate coaxially and integrally. The support shafts 29 and 29 are pivotally supported by a carrier 26 (described later) that rotates relative to the input shaft 4a and the output shaft 4b so as to be parallel to the input shaft 4a and the output shaft 4b.

  FIG. 3 is an exploded perspective view showing the configuration of the carrier 26 of the rotational transmission device according to the present invention. The carrier 26 includes a cylindrical rotor 26a, disk-shaped first carrier plate 26b and second carrier plate 26c, and two connecting members 26d and 26d that connect the first carrier plate 26b and the second carrier plate 26c. It has. The rotor 26a is a rotor of a direct drive motor, and is fixed to the first carrier plate 26b by means such as integral molding or welding. The input shaft 4a is inserted through a through-hole (not shown) drilled in the center of the rotor 26a and the first carrier plate 26b, and supports these so as to be relatively rotatable coaxially.

  The support shaft 29 to which the first planetary gear 24 and the second planetary gear 25 are fixed integrally is opposed between the first carrier plate 26b and the second carrier plate 26c with a through hole at the center of both carrier plates interposed therebetween. It is pivotally supported by a needle bearing 34 arranged at a position where The first carrier plate 26b and the second carrier plate 26c are connected by two connecting members 26d and 26d and fixed by screws 26e and 26e. The output shaft 4b is inserted through a through hole formed in the center of the second carrier plate 26c, and supports the second carrier plate 26c so as to be coaxially and relatively rotatable.

  The carrier 26 is geared by a ball bearing 30 so as to be relatively rotatable coaxially with the input shaft 4a and the output shaft 4b together with the first planetary gears 24 and 24, the second planetary gears 25 and 25, and the support shafts 29 and 29. It is supported by the housing 21, supported by the input shaft 4 a by the ball bearing 31 and the needle bearing 32, and supported by the output shaft 4 b by the ball bearing 33. In this way, the carrier 26 is configured to be able to rotate stably by being supported from both the inside and outside.

  A plurality of magnets 27 a, 27 a... Are arranged along the outer peripheral surface of the rotor 26 a of the carrier 26 so that the N pole and the S pole are alternately arranged. A coil 27b is provided around the part at a position facing the magnet 27a. A direct drive type speed change motor 27 that rotates coaxially with the input shaft 4a is formed by the rotor 26a, the magnet 27a, and the coil 27b, and controls the rotation direction and the rotation speed of the carrier 26 having the rotor 26a. The rotation of the input shaft 4a can be transmitted to the output shaft 4b by changing the transmission ratio steplessly.

  A reaction force motor 18 is connected to a midway portion of the input shaft 4 a of the column shaft 4 via a reduction gear mechanism 40. The reduction gear mechanism 40 includes a first gear 40a formed integrally with the outer peripheral portion of the input shaft 4a, a second gear 40b meshed with the first gear 40a, and connected to the output shaft of the reaction force motor 18. The reaction force motor 18 generates additional torque that changes the operation torque of the steering member 2 without changing the transmission ratio of rotation from the input shaft 4a to the output shaft 4b. The additional torque generated by the reaction force motor 18 is a resistance against a rotation operation applied to the steering member 2 by the driver. For example, a large additional torque is generated when the vehicle is traveling at a high speed and a small additional torque is generated when the vehicle is traveling at a low speed. Further, the control unit 15 controls the drive circuit 17 a that drives the reaction force motor 18.

  In the steering device including the rotation transmission device having the above-described configuration, when the steering member 2 is rotated for steering, the input shaft 4a of the column shaft 4 connected to the steering member 2 rotates and the end of the input shaft 4a is rotated. The 1st sun gear 22 formed in the part rotates.

  Here, when the speed change motor 27 is not driven to rotate and the carrier 26 does not rotate, the first planetary gears 24 and 24 are rotated by the respective support shafts 29 and 29 by the rotation of the first sun gear 22. The second planetary gears 25, 25 rotate together with the first planetary gears 24, 24. The second sun gear 23 is rotated by the rotation of the second planetary gears 25, 25, and this rotation is transmitted from the output shaft 4 b to the pinion shaft 7 through the intermediate shaft 6, and the rack shaft 10 moves in the axial direction. It is converted and the direction of the wheels 13 and 13 is changed.

  At this time, the transmission of rotation from the input shaft 4a having the first sun gear 22 to the output shaft 4b having the second sun gear 23 is the number of teeth of the first planetary gears 24, 24 and the second planetary gears 25, 25. This is performed at a fixed transmission ratio determined according to the ratio with the number of teeth, and the wheels 13 and 13 are steered in the operation direction of the steering member 2 by an angle corresponding to the operation amount.

  On the other hand, when the transmission motor 27 is rotationally driven and the carrier 26 is rotated in the same direction as the input shaft 4a, the rotation of the first sun gear 22 is caused by the first planetary gears 24, 24 revolving together with the carrier 26 and The second planetary gears 25 and 25 are transmitted to the second sun gear 23 through the rotation of the second planetary gears 25 and 25, and the second sun gear 23 is increased at a speed increased from the first sun gear 22 by the revolution speed of the carrier 26 by the motor. Rotate. At this time, the transmission of rotation from the input shaft 4a to the output shaft 4b is not less than a fixed transmission ratio determined according to the ratio between the number of teeth of the first planetary gears 24, 24 and the number of teeth of the second planetary gears 25, 25. The wheels 13 and 13 are steered more than an angle corresponding to the operation amount of the steering member 2.

  On the other hand, when the speed change motor 27 is driven to rotate and the carrier 26 is rotated in the direction opposite to the input shaft 4 a, the second sun gear 23 is decelerated from the first sun gear 22 by the revolution speed of the carrier 26. Rotates at speed. At this time, the transmission of rotation from the input shaft 4a to the output shaft 4b is not more than a fixed transmission ratio determined according to the ratio between the number of teeth of the first planetary gears 24, 24 and the number of teeth of the second planetary gears 25, 25. The wheels 13 and 13 are steered smaller than an angle corresponding to the operation amount of the steering member 2.

  The rotational direction and rotational speed of the speed change motor 27 are determined by the control unit 15 according to the detection results of the steering angle sensor 14 and the vehicle speed sensor 16, and a drive command is given to the drive circuit 17b, whereby the speed direction of the speed change motor 27 is determined. And the rotation speed is controlled. Thus, for example, when control is performed so that the transmission ratio is large during low-speed traveling and the transmission ratio is small during high-speed traveling, driving operation during low-speed traveling can be facilitated, and stability during high-speed traveling can be improved. In addition, in order to give resistance to the rotation operation of the steering member 2 performed by the driver, the control unit 15 controls the rotation of the reaction force motor 18 so that the small additional torque at the low speed traveling and the large additional torque at the high speed traveling. By generating the above, the driver can obtain a good steering feeling.

  In the rotation transmission device according to the present invention, the rotor of the direct drive type speed change motor 27 is a rotor 26a that is integrated with the first carrier plate 26b of the carrier 26, thereby comparing with the conventional rotation transmission device. Since the number of gears can be reduced, it is possible to suppress the collision noise of the gear generated when switching the rotation direction and the sliding noise accompanying the operation of the gear, and it is possible to reduce the size of the device and the number of parts. In addition, the cost can be reduced by reducing the number of assembly steps.

  In addition, in this Embodiment, although it was set as the structure provided with the 1st planetary gear 24 and the 2nd planetary gear 25 2 each, not only this but 1 or 3 or more may be sufficient. In addition, although the direct drive type speed change motor 27 rotor and the first carrier plate 26b are integrated, the second carrier plate 26c may be integrated. In addition, the first carrier plate 26b, the second carrier plate 26c, and the connecting member 26d are fixed by the screws 26e. However, the present invention is not limited to this, and may be fixed by other methods such as welding or integral molding. Further, the reaction force motor 18 may be configured as a direct drive motor, or may be configured without the reaction force motor 18. The rotation transmission device according to the present invention may be applied not only to the vehicle steering device but also to other devices. The rotation transmission device according to the present invention is configured to transmit rotation using a plurality of gears. However, the configuration is not limited thereto, and the same configuration is used for a rotation transmission device that transmits rotation using a pulley and a belt. You may apply.

It is a schematic diagram which shows the example of application of the rotational transmission apparatus which concerns on this invention in the steering apparatus of a vehicle. It is a longitudinal cross-sectional view which shows the structure of the rotational transmission apparatus which concerns on this invention. It is a disassembled perspective view which shows the structure of the carrier of the rotational transmission apparatus which concerns on this invention.

Explanation of symbols

1 rack and pinion type steering device 4 column shaft 4a input shaft 4b output shaft 22 first sun gear 23 second sun gear 24 first planetary gear 25 second planetary gear 26 carrier 26a rotor 26b first carrier plate 26c second carrier plate 27 Speed change motor 29 Support shaft

Claims (2)

A first sun gear;
A second sun gear supported coaxially with the first sun gear;
A first planetary gear meshing with the first sun gear;
A second planetary gear meshing with the second sun gear and rotating together with the first planetary gear;
A carrier that rotatably supports the first planetary gear and the second planetary gear about each axis, and rotates coaxially with the first sun gear and the second sun gear;
A rotation transmission device comprising: a motor that changes a rotation speed of rotation transmitted by each gear;
The motor is disposed coaxially with the first sun gear and the second sun gear;
A rotation transmission device, wherein the rotor of the motor and the carrier are integrated. The rotor has a cylindrical shape,
An input shaft that rotates integrally with the first sun gear or an output shaft that rotates integrally with the second sun gear passes through the rotor,
The rotation transmission device according to claim 1, wherein the carrier and the rotor are disposed so as to be relatively rotatable coaxially with the input shaft or the output shaft.

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