JP2002240729A - Steering device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a larger torque ratio from a drive member to an output member by an electric motor without enlarging the axial dimension or the outside diameter of a rotation ratio variable mechanism. SOLUTION: An input-side rotating body 41 integrally rotating with a steering shaft 12 and an output-side rotating body 42 integrally rotating with an output shaft 13 are totatably supported. A rotary shaft body 43 is rotatably supported. Multiple input-side planetary gears 74 supported to a carrier 44 are geared with an input-side ring gear 52 provided in the input-side rotating body 41 and an input-side sun gear 70 provided in the rotary shaft body 41. Multiple output-side planetary gears 75 supported to the same carrier 44 are geared with an output-side ring gear 62 provided in the output-side rotating body 42 and an output-side sun gear 71 provided in the rotary shaft body 43. The number of teeth of the output-side ring gear 62 is made to increase by 5% or less relative to the number of teeth of the input-side ring gear 52. An electric motor 96 with the rotary shaft body 43 set to the rotary shaft is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle steering system capable of changing a transmission ratio of a steering angle of a steering wheel to a steering angle of a steering wheel in a vehicle.

[0002]

2. Description of the Related Art Conventionally, as such a steering device, there is one disclosed in Japanese Patent Application Laid-Open No. H11-49003. In this steering apparatus, as shown in FIG. 9, a rotation input by steering is input to a case 150, and the rotation input is performed via a two-stage planetary gear mechanism having ring gears 151 and 152 provided on the case 150 as components. Output.
In this steering device, when the rotation of the rotor 154 of the electric motor 153 is controlled so as not to rotate relative to the case 150, the carrier 156 of the first stage planetary gear mechanism in which the sun gear 155 is provided on the rotor 154 is connected to the case 156. It does not rotate relative to 150. In addition, carrier 1
The sun gear 157 of the second stage planetary gear mechanism fixed to 56 does not rotate relatively, and the carrier 158 is
It rotates at the same speed as.

When the transmission ratio of the steering angle is changed, a motor 153 is controlled so that the rotor 154 rotates relative to the case 150, and a two-stage planetary gear mechanism in which ring gears 151 and 152 are provided in the case 150, respectively. The rotation decelerated in two stages by the carrier 1 in the second stage
In addition to the rotation output from 58. In such a steering device, the reduction ratio from the motor 153 to the carrier 158 is 2
Since it is largely secured by the planetary gear mechanism of the step,
The torque ratio of the output side to the motor 153 (the efficiency is 100
%, The reciprocal of the rotation ratio). Therefore, when there is an excessive reverse input from the wheel side to the steering device while the vehicle is traveling, the reverse input makes it difficult for the motor to be reversely driven, and the steering angle of the steered wheels with respect to the steering angle of the steering wheel at that time is reduced. It is difficult to deviate from the target value.

[0004] In the steering apparatus disclosed in the same Japanese Patent Application Laid-Open No. 11-49003, as shown in FIG.
The rotation input input to first case 160 is output from second case 161 that is rotatable relative to first case 160. Here, the first case 160 is
If the motor 163 is controlled so that the motor 62 does not rotate relative to the first case 160, the second case 161 does not rotate relative to the first case 160, and the rotation of the first case 160 corresponds to the rotation ratio “1”.
Is output from the second case 161.

When the transmission ratio of the steering angle is changed, the first
Motor 163 is controlled such that rotation shaft 162 rotates relative to case 160. And the first case 16
The pinion gear 166 meshing with the input side ring gear 164 provided on the second case 161 and the output side ring gear 165 provided on the second case 161 causes the second case 161 to rotate relative to the first case 160. This rotating shaft 16
The rotation based on the relative rotation of 2 adds to the rotation of the second case 161. Also in such a steering device, the reduction ratio from the motor to the second case 161 is largely ensured by the differential gear device including the two ring gears 164 and 165 having different numbers of teeth. A large torque ratio of 161 can be secured.

[0006]

However, in the steering apparatus shown in FIG. 9 disclosed in Japanese Patent Application Laid-Open No. H11-49003, in order to secure a large torque ratio from the motor to the output side, it is necessary to adjust the respective sun gears 155 and 157. It is necessary to increase the diameter of the ring gears 151 and 152. on the other hand,
Since the diameters of the sun gears 155 and 157 supported by the rotating shaft cannot be so small, the ring gear 1
There is a problem that the diameters of 51 and 152 increase, the maximum diameter of the planetary gear device increases, and the steering device becomes larger in the radial direction.

On the other hand, in the steering apparatus shown in FIG. 10 disclosed in Japanese Patent Application Laid-Open No. H11-49003, the motor 1 is provided without increasing the diameter of the differential gear apparatus having no sun gear.
A large torque ratio on the output side with respect to 63 can be secured. However, in this differential gear device, in order to mesh a common pinion gear 166 with both ring gears 164 and 165 having a difference in the number of teeth, both ring gears 164 and 1
It is necessary to make a large difference in the transfer coefficient of 65. For this reason, the difference in the number of teeth between the two ring gears 164 and 165 needs to be two, and the number of pinion gears 166 that can mesh with the two ring gears 164 and 165 is limited to two or one. As a result, the load borne by each pinion gear 166 is larger than when three planetary gears can be provided like a planetary gear mechanism. Therefore, it is necessary to enlarge both the ring gears 164, 165 and the pinion gear 166 in the axial direction or the radial direction in order to secure the strength against the meshing force, and the differential gear mechanism becomes large in the axial direction or the radial direction. However, there is a problem that the size increases in the axial or radial direction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to eliminate the need for increasing the axial size or outer diameter of a rotation ratio variable mechanism by using a drive member driven by an electric motor and an output member. It is an object of the present invention to provide a vehicle steering system capable of obtaining a larger torque ratio up to the above.

[0009]

According to a first aspect of the present invention, there is provided an input-side rotating body rotatably supported, and an input-side ring gear provided on the input-side rotating body. A rotating shaft that is rotatably supported on the same axis as the input-side rotator and that can be driven to rotate relative to the input-side rotator by an electric motor; and rotates on the same axis as the input-side rotator. An output-side rotator that is supported, an output-side ring gear provided on the output-side rotator, an input-side sun gear provided on the rotary shaft, and an output-side provided on the rotary shaft. A sun gear, a carrier rotatably supported on the same axis as the rotating shaft of the rotating shaft body, and an input planetary gear rotatably supported by the carrier and meshed with the input ring gear and the input sun gear. , And summarized in that and an output side planetary gears mesh with the output-side ring gear and the output side sun gear is rotatably supported on the carrier.

According to the first aspect of the present invention, the torque ratio between the rotating shaft driven by the electric motor and the output rotating body is determined by the number of teeth of the output ring gear and the number of teeth of the input ring gear. It is determined. Further, the number of input-side planetary gears provided between the input-side sun gear and the input-side ring gear is determined from the sum of the respective numbers of teeth of the input-side sun gear and the input-side ring gear. Similarly, the number of output-side planetary gears provided between the output-side sun gear and the output-side ring gear is determined from the sum of the respective numbers of teeth of the output-side sun gear and the output-side ring gear. For this reason, it is not necessary to make the diameters of the input side and output side ring gears so large with respect to the diameters of the input side and output side sun gear, so that the rotation ratio variable mechanism including the two-stage planetary gear mechanism is made so large in the radial direction. A larger torque ratio is obtained without any. Further, since the number of planetary gears meshing with the input side ring gear and the output side ring gear is not limited to two, it is not necessary to increase the strength of each input side gear and each output side gear with respect to the meshing force so much. Since the size does not need to be increased in the axial or radial direction, the rotation ratio variable mechanism does not increase in the axial or radial direction. Therefore, a larger torque ratio from the motor drive unit to the steering output unit can be obtained without increasing the axial length and the outer diameter of the transmission ratio variable device unit.

According to a second aspect of the present invention, in the first aspect, the electric motor is provided, and the electric motor is provided with a rotor having the rotating shaft as a rotating shaft. I do.

According to the invention described in claim 2, according to claim 1,
In addition to the operation of the invention described in the above, since the center axis of the rotor of the electric motor is arranged so as to coincide with the center axis of the variable rotation ratio mechanism including the two-stage planetary gear mechanism, The projected area in the central axis direction is less likely to be increased by the electric motor, as compared with a configuration in which the rotary shaft body is rotationally driven by an electric motor having a rotary shaft. Therefore, the outer diameter including the electric motor that rotationally drives the rotating shaft body can be further reduced.

According to a third aspect of the present invention, in the second aspect of the present invention, there is provided a structure in which the input side rotator, the output side rotator and the carrier do not exist outside the rotor, and The gist of the present invention is that the motor includes a stator arranged outside the rotor, and the stator is fixed to a non-rotating portion provided outside the rotor and not rotating.

According to the invention described in claim 3, according to claim 2
In addition to the operation of the invention described in (1), since the stator of the electric motor is provided in the non-rotating portion where the stator does not rotate, a complicated power supply device such as a slip ring is not required for power supply to the stator.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the structure is such that the rotating shaft body formed so as to include the output side rotating body, and at least a part of the rotating shaft body includes the output shaft. The input-side rotating body formed so as to include the side ring gear, the input-side ring gear provided on the output-side rotating body side in the axial direction with respect to the output-side ring gear, and the axial direction with respect to the output-side sun gear. The invention further includes an input-side sun gear provided on the output-side rotating body side.

According to the invention set forth in claim 4, according to claim 3,
In addition to the operation of the invention described in the above, since the input side rotating body is present outside the output side rotating body outside the rotating shaft body, the clutch for regulating the relative rotation between the rotating shaft body and the input side rotating body is provided. The device can be provided on the output rotating body side with respect to the rotation ratio conversion mechanism including the two planetary gear mechanisms.

According to a fifth aspect of the present invention, in the first aspect of the invention, a plurality of the input-side planetary gears and the plurality of the output-side planetary gears are provided, and A part of the plurality of input-side planetary gears and the rest thereof are urged to rotate in opposite directions, and a part of the plurality of output-side planetary gears and the rest thereof are combined. The gist of the present invention is to provide an urging means for urging to rotate in opposite directions.

According to the invention described in claim 5, according to claim 1,
In addition to the effect of the invention according to any one of claims 4 to 4, even in a state where rotation by steering is not input from the input side rotating body, a part of the plurality of input side planetary gears is The input side ring gear and the input side sun gear come into contact with each other in a direction rotating in one direction with respect to each central axis.
On the other hand, the rest of the plurality of input-side planetary gears abut on the input-side ring gear and the input-side sun gear in directions that rotate in opposite directions with respect to their respective central axes. For this reason, even when the rotation by the steering is not applied to the input-side rotating body, rattling between the input-side ring gear and the input-side sun gear and each input-side planetary gear hardly occurs. Also, since the output side planetary gear is similarly supported,
The rattling between the output side ring gear and the output side sun gear and each output side planetary gear hardly occurs. Therefore, during traveling of the vehicle, an impact is hardly generated by the rotation ratio variable mechanism due to inertia of each gear, a reverse input from a steered wheel, or the like, so that an impact is hardly generated on the steering wheel, and the driver does not easily feel discomfort.

According to a sixth aspect of the present invention, in the first aspect of the present invention, there is provided an electric control for connecting and fixing the rotary shaft and the input side rotary body. The gist of the present invention is to provide a clutch device.

According to the invention of claim 6, according to claim 1,
In addition to the effects of the invention according to any one of claims 5 to 5, the relative rotation of the rotating shaft with respect to the input-side rotating body is regulated as necessary, and the input-side rotating body and the rotating shaft are directly connected. You. For this reason, in a state where the rotating shaft body is no longer controlled according to the rotation of the input-side rotating body due to the steering, the input-side rotating body and the output-side rotating body can be connected in a state where their rotational positional relationship is fixed. . Therefore, the steering function can be ensured even when a failure of the electric system occurs while the vehicle is running and power is not supplied to the steering device.

According to a seventh aspect of the present invention, in the first aspect of the present invention, the input-side rotator or the output-side rotator is a cylinder, and cannot rotate relative to each other. The gist is that a rotation transmission shaft that is relatively movable in the direction of the rotation axis is supported inside the rotation transmission shaft.

According to the invention of claim 7, according to claim 1,
A telescopic function or a shock absorbing function can be provided in addition to the operation of the invention described in any one of the sixth to sixth aspects.

[0023]

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 2, the vehicle steering system 10
Is a case body 11 as a non-rotating portion supported on the vehicle side.
And a steering shaft 12 and an output shaft 13 extending from the case body 11. A steering wheel (not shown) is mounted on the steering shaft 12. The output shaft 13 is connected to an input portion of a steering gear box via a connection shaft and a pinion shaft (not shown). In the present embodiment, the steering shaft 12 and the output shaft 13 are both rotation transmission shafts.

The case body 11 comprises a fixed case part 14 and a movable case part 15. The fixed case portion 14 is fixed to the vehicle, and the movable case portion 15 is supported in a movable state with respect to the fixed case portion 14.

The fixed case section 14 includes a first case 16, a motor case 17, a second case 18, and a third case 19. The first case 16 and the second case 18 are fixed to the vehicle, and the motor case 17 is supported between the two cases 16, 18 connected by bolts 20. The third case 19 is fixed so as to be fitted to the end of the second case 18.

The movable case section 15 includes a slide case 21.
And a tilt case 22. Slide case 2
1 is supported so as to be movable in the axial direction while being fitted to the third case 19. The tilt case 22 is supported on the end of the slide case 21 by a connecting portion 23 so as to be tiltable in the vertical direction of the vehicle.

As shown in FIG. 3, the steering shaft 12 is attached to the support tube 2 fixed to the tilt case 22.
4 rotatably supported. One end of a sub shaft 26 is connected to an end of the steering shaft 12 via a universal joint 25. The other end of the sub shaft 26 is supported in the fixed case portion 14 so as to be rotatable and movable in the axial direction. The steering shaft 12 and the slide case 2 together with the tilt case 22
1 and the sub shaft 26 can be tilted up and down. Further, the steering shaft 12 is movable in the axial direction of the sub shaft 26 with respect to the fixed case portion 14 together with the slide case 21, the tilt case 22, and the sub shaft 26. That is, the steering device 10 has a tilt function of adjusting the position of the steering wheel in the vertical direction of the vehicle and a telescopic function of adjusting the position of the steering wheel in the longitudinal direction of the vehicle.

On the other hand, the output shaft 13 is supported by the fixed case portion 14 so as to be rotatable and movable in the axial direction. As shown in FIG. 2, the telescopic operation of the steering shaft 12 includes a telescopic motor 27 and a gear mechanism 28 provided on the fixed case portion 14, a support member 29 provided on the slide case 21, a gear mechanism 28 This is performed by a trapezoidal screw 30 supported on a member 29. The telescopic motor 27 moves the trapezoidal screw 30 via the gear mechanism 28 in the axial direction. Support member 2
9 fixes one end of the trapezoidal screw 30 so that it cannot rotate.
When the telescopic motor 27 is rotated, the gear mechanism 28 moves on the trapezoidal screw 30, so that the movable case 15 is fixed via the support member 29 to which one end of the trapezoidal screw 30 is fixed. To the output shaft 13 in the axial direction.

On the other hand, the tilting operation of the steering shaft 12 includes the tilt motor 31 and the gear mechanism 32 provided in the tilt case 22, the female screw member 33 provided in the slide case 21, the gear mechanism 32 and the female screw member 3.
3 is carried out by a trapezoidal screw 34 supported. The tilt motor 31 drives a trapezoidal screw 34 via a gear mechanism 32 to rotate. The female screw member 33 is attached to the slide case 21.
, And is supported in a state where the ends of the trapezoidal screws 34 are screwed together. And the tilt motor 31
Is rotated, the gear mechanism 32 rotates the trapezoidal screw 34 to move in and out of the female screw member 33, and the tilt case 22 is moved to the slide case 21 via the trapezoidal screw 34 supported by the swingable female screw member 33. Tilt up and down.

Further, as shown in FIG. 1, the steering device 10 includes a rotation ratio variable mechanism 40 for changing the rotation ratio of the rotation of the output shaft 13 to the rotation of the steering shaft 12. The rotation ratio variable mechanism 40 is provided in the fixed case portion 14. Variable rotation ratio mechanism 40
Are the input-side rotator 41, the output-side rotator 42, and the rotary shaft 4
3, the carrier 44 and the like.

The input-side rotator 41 includes a sleeve portion 45 containing the auxiliary shaft 26 and a gear portion 46 having a diameter larger than that of the sleeve portion 45. The input side rotator 41 includes a bearing 4 provided between the sleeve 45 and the second case 18.
7 and a bearing 48 provided between the gear portion 46 and the second case 18 supports the second case 18 so as to be rotatable and immovable in the axial direction.

An input side sleeve 50 is supported inside the sleeve portion 45 via a bearing 49 so as to be rotatable and immovable in the axial direction. The auxiliary shaft 26 is supported by the input side sleeve 50 by a spline connection so as to be relatively non-rotatable and movable in the axial direction.

The input side rotator 41 includes an input side sleeve 50.
Is connected to the input side sleeve 50 so as to rotate integrally with the input side sleeve 50. on the other hand,
An input side ring gear 52 is provided on the inner peripheral surface of the gear portion 46.

The connecting mechanism 51 is, as shown in FIGS.
The input side sleeve 50 includes a plurality of rib-shaped engaging portions 50 a provided on the outer peripheral surface, a rubber damper 53, a holding metal fitting 54, and a plurality of keys 55. Each rib-shaped engaging portion 50
a is formed so as to extend in the axial direction, and is provided on the same circumference at equal angular intervals. Rubber damper 53
Is formed in a substantially cylindrical shape that covers the outer peripheral surface of the input side sleeve 50 including the respective rib-shaped engagement portions 50a, and is fitted to the input side sleeve 50 outside. The rubber damper 53 is provided for each of the rib-shaped engagement portions 5.
The portions abutting on both side surfaces of Oa are formed thick. The holding fitting 54 is formed in a shape that rises and falls in the radial direction along the outer peripheral surface of the rubber damper 53 that is externally fitted to the input side sleeve 50, and is externally fitted so as to be in close contact with the outer peripheral surface of the rubber damper 53. Each key 55 is press-fitted into a hole provided in the input-side rotating body 41 and abuts against the holding metal fitting 54 in its groove. The rotation torque is transmitted from the input side sleeve 50 via the rubber damper 53 to the input side rotating body 41, and the input side rotating body 41 rotates relative to the input side sleeve 50 within a certain angle due to the elastic deformation of the rubber damper 53. ing. The coupling mechanism 51 thus configured
Absorbs the sudden rotation of the input side rotating body 41 irrespective of the rotation of the steering shaft 12, and the input side rotating body 4
Sudden rotation of the steering shaft 12 due to one rotation is buffered.

The rotation of the input-side rotator 41 due to steering of the steering wheel is regulated by a key lock mechanism. As shown in FIG. 4, the key lock mechanism includes a key cylinder 56 provided at a position opposite to the connection mechanism 51 in the second case portion 18. The key cylinder 56 has an end fitted and fixed in a hole 18 a provided in the second case portion 18. The key cylinder 56 extends the key portion 57 toward the input side rotating body 41 by a lock operation on an operation unit (not shown) of the key lock mechanism. The key portion 57 fits into a hole 41 a provided in the input-side rotator 41 and regulates the rotation of the input-side rotator 41 with respect to the second case portion 18. The key lock mechanism configured as described above prevents the steering wheel from being steered by a lock operation on the operation unit.

As shown in FIG. 1, the output side rotating body 42
The output shaft 13 includes a sleeve portion 58 externally fitted to the output shaft 13 and a large-diameter gear portion 59 disposed on the outer peripheral side of the sleeve portion 58. The output side rotating body 42 is connected to the sleeve portion 58 and the first
A bearing 60 provided between the case 16 and a bearing 61 provided between the sleeve portion 58 and the input-side rotator 41 allows the fixed case portion 14 to rotate and not move in the axial direction. It is supported by.

The sleeve portion 58 supports the output shaft 13 so as to be integrally rotatable. When an excessive external force is applied to the output shaft 13 in the axial direction toward the steering shaft 12, the sleeve portion 58 moves relative to the steering shaft 12. Allow. That is, the steering device 10 has an impact absorbing function to prevent the entire steering device 10 from moving to the driver's seat side by immersing the output shaft 13 in the fixed case portion 14 at the time of a vehicle collision.

The gear portion 59 is provided so as to be included in the gear portion 46 of the input side rotating body 41, and is disposed on the input side rotating body 41 side in the axial direction with respect to the input side ring gear 52. 62 are provided. The number of teeth of the output side ring gear 62 is greater than the number of teeth of the input side ring gear 52. In the present embodiment, the number of teeth of the input side ring gear 52 is set to “87”, and the output side ring gear 62
Is "91".

The rotating shaft 43 is formed in a cylindrical body, and the motor shaft 6 is provided so as to include the output side rotating body 42.
3, a sun gear 64 and a connecting sleeve 65, which are formed by integrally connecting the motor shaft 63 and the sun gear 64 by the connecting sleeve 65. The rotating shaft 43 is fixed to a fixed case part by a bearing 66 provided between the motor shaft part 63 and the first case 16 and a bearing 67 provided between the motor shaft part 63 and the second case 18. 1
4 and the output side rotating body 42 are supported so as to be rotatable relative to each other and immovable in the axial direction.

On the motor shaft portion 63, a cylindrical rotor magnet 68 as a rotor is externally fitted and fixed between both bearings 66 and 67. The sun gear 64 is provided on the input side ring gear 5.
2 and an output-side sun gear portion 71 that faces the output-side ring gear 62. The number of teeth of the input-side sun gear 70 is greater than the number of teeth of the output-side sun gear 71. In the present embodiment, the number of teeth of the input-side sun gear 70 is set to “51”, and the number of teeth of the output-side sun gear 71 is set to “47”.

The carrier 44 is provided without being directly connected to the input-side rotator 41 and the output-side rotator 42. As shown in FIG. 5, the carrier 44 is rotatable by a thrust bearing 72 provided between the input side rotating body 41 and a thrust bearing 73 provided between the carrier 44 and the output side rotating body 42. It is supported by the input side rotating body 41 and the output side rotating body 42 so as not to be movable in the axial direction.

The carrier 44 has an input ring gear 52
In addition, six input-side planetary gears 74 meshing with the input-side sun gear 70 are supported at substantially equal angular intervals.
The output side ring gear 62 and the output side sun gear portion 71
The output-side planet gears 75 meshing with each other are supported at substantially equal angular intervals. Therefore, the number of teeth of each input-side planetary gear 74 is smaller than the number of teeth of the output-side planetary gear 75. In the present embodiment, the number of teeth of the input side planetary gear 74 is “18”, and the number of teeth of the output side planetary gear 75 is “22”.
It has been.

The carrier 44 includes a first member 76, a second member 77, six support shafts 78, and six snap rings 79.
It is composed of In the present embodiment, the first member 76,
The second member 77, the support shaft 78 and the snap ring 79 constitute an urging means.

As shown in FIGS. 5, 6, and 7, the first member 76
Includes a cylindrical portion 80 extending in the axial direction, and three gear support portions 81 provided on the outer peripheral surface of the cylindrical portion 80 at equal angular intervals on the circumference. A support shaft 78 is supported by each gear support portion 81, and an input planetary gear 74 and an output planetary gear 75 are rotatably supported on each support shaft 78, respectively.

The second member 77 has a disk-shaped base 82 fitted externally to the cylindrical portion 80, and three gear support portions 83 provided at equal angular intervals on the periphery of the end surface of the base 82. . A support shaft 78 is supported by each gear support portion 83, and an input planetary gear 74 and an output planetary gear 75 are rotatably supported on each support shaft 78, respectively.

Then, the first member 76 and the second member 77
The base 82 of the second member 77 is attached to the cylindrical portion 80 of the first member 76.
Are fitted, and the gear support portions 81 of the first member 76 and the gear support portions 83 of the second member 77 are combined in a state of being alternately adjacent to each other on the circumference. At this time, both members 76, 77
Is a slight gap G between the adjacent gear support portions 81 and 83.
(Shown in FIGS. 6 and 7) are formed so as to be relatively rotatable by a certain angle.

Each of the gear support portions 81 and 83 has a support shaft 7.
Each of the end portions 78a of the pair 8 extends in the axial direction. Then, on both sides of the combined members 76 and 77,
Three snap rings 79 are attached to each of the six end portions 78a from the inner peripheral side. Each of the snap rings 79 is connected to a corresponding one of the three
The input side planetary gear 74 and the output side planetary gear 75 and the three input side planetary gears 74 and the output side planetary gear 75 supported by the second member 77 are relatively rotated in opposite directions. Are mounted so as to urge both members 76 and 77.

The carrier 44 thus configured includes input and output planetary gears 74 and 75 supported by the first member 76 and input and output planetary gears supported by the second member 77. 74, 75 are the input side ring gear 5
2 and the input-side sun gear unit 70 are attached in a state of being in close contact with each other. At the same time, the output side ring gear 62
And the output-side sun gear portion 71 in close contact with each other.

The variable rotation ratio mechanism 4 configured as described above
0 transmits the rotation inputted from the input side rotating body 41 to the output side rotating body 42 through the transmission path of the input side planetary gear 74, the carrier 44 and the output side planetary gear 75. At the same time, the input side planet gear 74, the sun gear 64 and the output side planet gear 75
Is output to the output side rotating body 42 also in the transmission path of

At this time, when the rotation shaft 43 is rotated together with the input side rotation body 41 so as not to rotate relative to the input side rotation body 41, the rotation ratio variable mechanism 40 operates together with the rotation shaft body 43 and the carrier 44. The output rotator 42 is rotated integrally with the input rotator 41. This is the rotating shaft 43,
This is because the input-side rotator 41 and the carrier 44 rotate integrally without rotating relative to each other. That is, the rotation ratio variable mechanism 40 transmits the rotation inputted to the input side rotating body 41 from the steering shaft 12 by steering the steering wheel to the output side rotating body 42 at the transmission ratio “1”.

When the rotation shaft 43 is relatively rotated with respect to the input-side rotator 41, the rotation-ratio variable mechanism 40 rotates the input-side rotator 41 at a transmission ratio represented by the following equation (1). The relative rotation of the shaft 43 is transmitted to the output-side rotator 42. Here, the rotating shaft 43 with respect to the input rotating body 41
Is set to Nm, and the relative rotation speed of the output-side rotator 42 to the input-side rotator 41 is set to N2. The number of teeth of the input side ring gear 52 is R1, and the number of teeth of the output side ring gear 62 is R2.

Nm / N2 = (R2−R1) / R2 (1) Here, since the efficiency between the respective gears can be made almost 100%, the following equation (2) is established. Here, the rotating shaft 4
3 is Tm, and the torque applied to the output side rotating body 42 is an output torque Tr2.

Tm / Tr2 = (R2-R1) / R2 (2) The above equation (1) is derived. The following equation (3) is established between the carrier 44 and the input-side planetary gear 74 from the balance of the torque. Here, the torque applied to the carrier 44 from the input-side planetary gear 74 is TC1, and the force with which the input-side planetary gear 74 meshes with the input-side sun gear 70 and the input-side ring gear 52 is f1. The radius from the rotation axis of the carrier 44 to the rotation axis of the support shaft 78 is rp. The meshing force f1 received by the input side planet gear 74 from the input side sun gear portion 70 and the input side ring gear 52 is 180 degrees opposite, and the direction applied to the gear 74 is the same direction.

TC1 = 2 × f1 × rp (3) Similarly, the following equation (4) is established between the carrier 44 and the output side planet gear 75. Here, the torque applied to the carrier 44 from the output-side planetary gear 75 is TC2, and the force with which the output-side planetary gear 75 meshes with the output-side sun gear 71 and the output-side ring gear 62 is f2.

TC2 = 2 × f2 × rp (4) Since the two torques TC1 and TC2 are equal and the radius rp is equal, the engagement f1 = f2 = f. Accordingly, since the engagement force f applied to the input side ring gear 52 and the output side ring gear 62 is equal, the torque TR1 applied to the input side ring gear 52 and the torque T applied to the output side ring gear 62
R2 is represented by the following equations (5) and (6), respectively. Here, the radius from the rotation center of the input side ring gear 52 is rR
1, and the radius of the output side ring gear 62 from the rotation center is rR2. The module of each gear is denoted by M.

[0057] Here, when the product of the engagement force f and M / 2 is replaced by a constant k, the following equations (5-1) and (6-1) are established.

TR1 = k × R1 (5-1) TR2 = k × R2 (6-1) Here, the torque TR1 of the input-side rotating body 41 when the torque Tm is applied to the rotating shaft 43, and From the balance with the torque TR2 of the output side rotating body 42, the following equation (7) is established.

TR2 = TR1 + Tm (7) By substituting equations (5-1) and (6-1) into equation (7), the following equation (8) is derived. Tm = Tr2-Tr1 = k × (R2-R1) (8) Then, the following expression (2) is derived from the expressions (6-1) and (8).

Tm / Tr2 = k (R2−R1) / k (R2) = (R2−R1) / R2 (2) Therefore, the rotation ratio variable mechanism 40 includes the input side ring gear 52.
The rotation of the rotary shaft 43 with respect to the input rotary body 41 is transmitted to the output rotary body 42 at a reduction rotation ratio determined by the number of teeth of the output ring gear 62 and the number of teeth of the output ring gear 62. In this embodiment,
Since R1 = 87 and R2 = 91, the torque ratio Tm
/Tr2=(91−87)/91=1/22.75, and a torque ratio of 20 times or more is obtained.

As shown in FIG. 1, the outer peripheral portion of the sleeve portion 58 which is a component of the output side rotating body 42 is
An electrically controlled clutch device 84 for directly connecting the input rotary member 41 to the input-side rotating body 41 as necessary is provided.

As shown in FIG. 5, the clutch device 84
A fixing portion 8 formed so as to include the rotating shaft 43.
5 and a rotating unit 86. The fixing portion 85 includes an annular yoke 87 fixed to the second case portion 18 and a yoke 87.
And an exciting coil 88 provided in the circumferential groove of the above.
A power supply line 89 is connected to the exciting coil 88 through a hole provided in the second case 18.

The rotating section 86 includes a support member 90, a plurality of compression coil springs 91, a first clutch plate 92, and a second clutch plate 93. The support member 90 is formed in an annular shape,
The rotary shaft 43 is externally fitted and fixed to the motor shaft 63.
The support member 90 includes a tubular portion 94 fixed to the motor shaft portion 63 in a state of being fitted to the outside, and a flange portion 95 projecting radially from the outer peripheral surface of the tubular portion 94. Flange 95
Are provided with a plurality of holes that open toward the input side rotating body 41, and a compression coil spring 91 is mounted in each of the holes.

The first clutch plate 92 is formed in a substantially disk shape, and is loosely fitted to the cylindrical portion 94 so as to be movable in the axial direction and relatively non-rotatable. A clutch surface 92a is formed on an end surface of the first clutch plate 92 in the axial direction.
The first clutch plate 92 is urged by the compression coil springs 91 in a direction away from the flange 95. The second clutch plate 93 is fixed to the input-side rotating body 41 so as to rotate integrally therewith.
a is provided with a clutch surface 93a that comes into contact with the clutch surface 93a.

The clutch device 84 thus configured
When the power is supplied to the exciting coil 88, the first clutch plate 92 is moved toward the flange portion 95 of the rotating portion 86 against the urging force of each compression coil spring 91 via the yoke 87 and the support member 90. . Then, the first clutch plate 92
Is held at a position where the clutch surface 92a is not engaged with the clutch surface 93a of the second clutch plate 93, and the relative rotation of the rotating shaft 43 with respect to the input side rotating body 41 is allowed. In the state where power is not supplied to the exciting coil 88, the first
The clutch plate 92 is moved from the flange portion 95 side to the second clutch plate 93 side by the urging force of each compression coil spring 91. Then, the first clutch plate 92 is held at a position where its clutch surface 92a is engaged with the clutch surface 93a of the second clutch plate 93, and the input side rotating body 41 and the rotating shaft 43 are directly connected.

Further, as shown in FIG. 1, the steering device 10 is provided with an electric motor 96 for driving the rotary shaft 43 to rotate relative to the input rotary body 41. The electric motor 96 is an inner rotor type DC brushless motor, and includes a rotor magnet 68 fixed to the sleeve 58, a stator provided in the motor case 17, and the like. The stator includes a stator core 97, an exciting coil 98, and the like. And the electric motor 96
The rotation direction and the rotation speed are controlled by an electronic control unit (not shown) based on the vehicle condition such as the rotation position and the vehicle speed of the steering shaft 12 and the output shaft 13.

The electronic control unit controls the output shaft 1 with respect to the rotation angle of the steering shaft 12 based on the vehicle condition.
When the rotation angle of the rotating member 3 is one-to-one, the input-side rotating body 41
The electric motor 96 is controlled so that the rotating shaft 43 is not relatively rotated. Further, based on the vehicle condition, the output shaft 13 with respect to the rotation angle of the steering shaft 12 is determined.
In order to further increase the rotation angle of
The electric motor 96 is controlled so that the rotating shaft 43 rotates relatively faster in the same direction. On the other hand, when the rotation angle of the output shaft with respect to the rotation angle of the steering shaft 12 is made smaller, the electric motor 96 is controlled so that the rotation shaft 43 rotates faster in the reverse direction with respect to the input rotation body 41.

The operation of the present embodiment configured as described above will be described. In the steering device 10, when the input-side rotator 41 rotates with the steering, the relative rotation speed of the rotating shaft 43 with respect to the input-side rotator 41 is controlled by the electric motor 96. At this time, in a state where the rotation shaft 43 is controlled so as not to rotate relative to the input side rotation body 41, the rotation of the steering shaft 12 due to the steering of the steering wheel is output from the output shaft 13 at a rotation ratio of “1”. .

When the rotating shaft 43 is controlled to rotate relative to the input rotary member 41, the steering device 10 controls the rotation of the input rotary member 41 with respect to the input rotary member 41. The rotation obtained by adding the rotation based on the relative rotation of the rotating shaft 43 is output from the output shaft 13.

When the rotating shaft 43 is driven to rotate relative to the input rotary member 41 in the same direction, the steering device 10 determines the rotation of the input rotary member 41 in accordance with the steering by the rotation ratio. The output is output from the output shaft 13 at a rotation ratio larger than “1”. At this time, the steering device 10 outputs from the output shaft 13 at a higher rotation ratio as the relative rotation speed of the rotating shaft 43 with respect to the input-side rotating body 41 increases. Accordingly, when the electric motor 96 is controlled such that the rotating shaft 43 relatively rotates in the same direction at a higher relative speed with respect to the rotation of the input-side rotating body 41 due to the steering, the steering wheel is steered. Increase the steering angle of the steered wheels with respect to the angle.

On the other hand, when the rotating shaft 43 is driven to rotate relative to the input-side rotating body 41 in the opposite direction, the steering device 10 rotates the input-side rotating body 41 in accordance with the steering. Is output to the output shaft 13 at a rotation ratio smaller than the rotation ratio “1”. At this time, the steering device 10
As the relative rotational speed of the rotating shaft 43 in the reverse direction with respect to the input rotating body 41 increases, the output is outputted from the output shaft 13 with a smaller rotation transmission ratio. Therefore, when the electric motor 96 is controlled such that the rotating shaft 43 relatively rotates in the opposite direction at a higher relative speed with respect to the rotation of the input-side rotating body 41 due to the steering according to the vehicle condition, the steering wheel The steering angle of the steered wheels with respect to the steering angle is made smaller.

According to the embodiment described above, the following effects can be obtained. (1) The torque ratio from the rotating shaft 43 driven by the electric motor 96 to the output shaft 13 is determined by the number of teeth of the output side ring gear 62 and the number of teeth of the input side ring gear 52. The number of input-side planetary gears 74 provided between the input-side sun gear 70 and the input-side ring gear 52 is equal to the number of the input-side sun gear 70 and the output-side sun gear 71.
Is determined from the sum of the respective numbers of teeth. Similarly, the number of output-side planetary gears 75 provided between the output-side sun gear 71 and the output-side ring gear 62 is determined from the sum of the respective numbers of teeth of the output-side sun gear 71 and the output-side ring gear 62.

Therefore, unlike the conventional steering system shown in FIG. 9, the diameter of the ring gear 151 does not need to be so large as to the diameter of the sun gear 155, so that the rotation ratio variable mechanism does not need to be so large in the radial direction. , A larger torque ratio can be obtained. Further, since the number of pinion gears 166 meshing with the input side ring gear 164 and the output side ring gear 165 is not limited to two as in the conventional steering device shown in FIG. 10, each of the input side gears 52, 70, 74, and the output. It is not necessary to increase the strength of the gears 62, 71, 75 on the side with respect to the meshing force so much, and it is not necessary to increase the magnitude in the axial direction or the radial direction. The mechanism 40 does not grow in the axial or radial direction.

Specifically, in this embodiment, the electric motor 96
When the torque ratio “22” of the output side rotating body 42 to the input side sun gear portion 70 can be obtained, the ratio of the diameter of the input side ring gear 52 to the input side sun gear portion 70 is 87/51 = about 1.7, and the output side sun gear portion The ratio of the diameter of the output side ring gear 62 to the diameter of 71 is 91/47 = about 1.9. On the other hand, in the conventional steering device shown in FIG.
In order to obtain “0”, the reduction ratio of each planetary gear mechanism is set to 4.48.
It is necessary to do above. Therefore, the ratio of the diameter of the ring gear 151 to the diameter of the sun gear 155 and the sun gear 1
The ratio of the diameter of the ring gear 152 to the diameter of the diameter 57 needs to be 3.48 times or more.

Therefore, the torque ratio of the output shaft 13 to the rotating shaft 43 driven by the electric motor 96 can be increased without increasing the axial size or the outer diameter of the rotation ratio varying mechanism 40.

In particular, in this embodiment, the rotating shaft 43 is provided so as to be fitted on the output-side rotating body 42, and the output-side rotating body 42 is a cylindrical body capable of moving the output shaft 13 in the axial direction. . For this reason, since the diameter of the input side sun gear portion 70 and the output side sun gear portion 71 is large, it is possible to more effectively prevent the rotation ratio variable mechanism 40 from being enlarged in the radial direction.

(2) Since the central axis of the rotor of the electric motor 96 is arranged so as to coincide with the central axis of the rotation ratio variable mechanism 40, the electric motor having a rotary shaft outside the rotary shaft body 43 can be used. The projection area in the same central axis direction is less likely to be increased by the electric motor 96 as compared with the configuration in which the rotating shaft 43 is driven to rotate. Therefore, the outer diameter including the electric motor 96 that drives the rotary shaft 43 to rotate can be further reduced.

(3) The stator of the electric motor 96 in which the rotor is provided on the rotating shaft 43 containing the output side rotating body 42 is provided on the fixed case portion 14 which is not rotated by steering. Further, the electric motor 96 is a brushless motor that supplies power to the stator. Therefore, a complicated power supply device such as a slip ring is not required.

(4) Since the electric motor 96 having the rotating shaft 43 as a rotor is arranged on the output side of the variable rotation ratio mechanism 40 comprising a two-stage planetary gear mechanism, the input side rotating body 41 side , A coupling mechanism 51 and a key cylinder 56 can be provided.

(5) The rotation by steering is changed to the input-side rotating body 4.
Even when the input is not input from 1, three of the six input-side planetary gears 74 are respectively provided to the input-side ring gear 52 and the input-side sun gear 70 in a direction rotating in one direction with respect to each central axis. Abut On the other hand, the remaining three of the six input-side planetary gears 74 abut on the input-side ring gear 52 and the input-side sun gear 70 in directions that rotate in opposite directions with respect to the respective central axes. For this reason, even when the rotation by the steering is not applied to the input-side rotating body 41, the input-side ring gear 52 and the input-side sun gear portion 7
The rattling between 0 and each input-side planetary gear 74 hardly occurs. In addition, since the output-side planet gears 75 are similarly supported, rattling between the output-side ring gear 62 and the output-side sun gear portion 71 and each of the output-side planetary gears 75 is unlikely to occur. Therefore, the inertia of each gear,
Since an impact is unlikely to occur in the rotation ratio variable mechanism 40 due to a reverse input from a steered wheel or the like, an impact is unlikely to occur in the steering wheel, and the driver does not easily feel discomfort.

(6) When power is not supplied to the steering device 10, the relative rotation of the rotary shaft 43 with respect to the input rotary member 41 causes the clutch device 8 to be engaged when power is not supplied.
4, the input-side rotator 41 and the output-side rotator 42 are directly connected. For this reason, in a state where the rotation shaft 43 is no longer controlled in accordance with the rotation of the input rotation body 41 due to the steering, the input rotation body 41 and the output rotation body 42 are not controlled.
The rotational position relationship between the two does not become uncontrollable.
Therefore, the steering function is ensured even when a failure of the electric system occurs while the vehicle is running and power is not supplied to the steering device 10.

Further, in a configuration in which a worm wheel provided on an output shaft of an electric motor rotates a worm wheel to rotate an output shaft, as in a vehicle steering system disclosed in Japanese Patent Application Laid-Open No. 11-198830. Since the efficiency of the worm gear is about 40%, the power loss increases. On the other hand, in the present embodiment, since the worm gear is not used to reduce the rotation output of the electric motor 96, the efficiency of each gear is about 80%, and the power loss accompanying the transmission of rotation is reduced. For this reason, the electric power constantly supplied to the clutch device 84 is sufficiently supplemented.

(7) Three of the six input-side planetary gears 74 supported by the carrier 44 and the remaining three of the input-side planetary gears 74 are urged to rotate relative to each other in opposite directions. The input side ring gear 52 and the input side sun gear 70 are engaged with each other. Similarly, three of the six output planetary gears 75 and the remaining three of the six output planetary gears 75 supported by the carrier 44 are urged to rotate relative to each other in opposite directions, and the output side ring gear 75 is rotated. 62 and the output side sun gear 71.

For this reason, the rotating shaft of the carrier 44 rotatably supported by the input-side rotator 41 and the output-side rotator 42 and the rotary shaft 43 is set to the two rotators 41 and 42.
Is supported in a state of being in good agreement with the rotation axis of

(8) Since a relative rotation is allowed between the steering shaft 12 and the input side rotating body 41 by a certain relative angle due to the elastic deformation of the rubber damper 53, the steering shaft 12 due to the torque fluctuation of the electric motor 96 is changed. Rotational vibration is damped. For this reason, the electric motor 9
The torque fluctuation of No. 6 is not directly transmitted to the steering wheel, and the driver is unlikely to have discomfort.

(9) Since the electric motor 96 which is a brushless motor is of the inner rotor type, the inertia is small and the controllability is excellent. For this reason, it is possible to more easily perform more sophisticated control such as increasing the rotation ratio as the steering angle of the steering wheel increases. (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. The vehicle steering system according to the present embodiment differs from the first embodiment in that the stator of the electric motor 96 provided on the case body 11 that does not rotate with steering is changed to the input-side rotator 101 that rotates with steering. Only the structure provided in the first embodiment is different from the first embodiment.

As shown in FIG. 8, the vehicle steering system 100 of the present embodiment includes an input-side rotating body 101 that rotates integrally with a steering shaft (not shown) and an output shaft (not shown) at an input portion of a steering gear box (not shown). And an output-side rotator 102 that is connected through the rotator 102.

The input-side rotating body 101 is formed in a substantially cylindrical shape with a bottom, and an input-side ring gear 103 is fixed to an inner peripheral surface thereof. The output side rotating body 102 is formed in a substantially bottomed cylindrical shape, and is connected to the input side rotating body 101 by a connection structure (not shown) so as to be relatively rotatable and inseparable in the axial direction. An output side ring gear 104 is provided on the inner peripheral surface of the output side rotating body 102. The number of teeth of the output side ring gear 104 is set to be larger than the number of teeth of the input side ring gear 103 by 5% or less.

The input rotator 101 and the output rotator 102
, There are provided six input-side planetary gears 106 and output-side planetary gears 107 each supported by a carrier 105. Each input-side planet gear 106 is meshed with the input-side ring gear 103, and each output-side planet gear 107 is meshed with the output-side ring gear 104, respectively. The number of teeth of each input-side planetary gear 106 is smaller than the number of teeth of each output-side planetary gear 107.

The carrier 105 includes a first member 108 and a second member 109 similar to the carrier 44 of the first embodiment.
It has. The first member 108 includes three support shafts 110, each of which has an input planetary gear 106
And the output side planetary gear 107 is supported one by one. Similarly, the second member 109 includes three support shafts 110, and each of the support shafts 110 supports one input-side planetary gear 106 and one output-side planetary gear 107, respectively. The two members 108 and 109 are combined in a slightly rotatable state, and are relatively rotated in opposite directions by a biasing member (not shown) similar to the snap ring 79 in the first embodiment. Combined in an energized state. Therefore, the input side planetary gear 106 and the output side planetary gear 107 supported by the first member 108
And the input-side planetary gear 1 supported by the second member 109
06 and the output side planet gear 107 are supported in a state where they are urged to rotate relative to each other in opposite directions.

A rotating shaft 111 as a rotating shaft is provided inside the carrier 105. An input side sun gear 112 meshing with each input side planet gear 106 and an output side sun gear 113 meshing with each output side planet gear 107 are fixed to the rotating shaft 111. Input side sun gear 11
The number of teeth of 2 is larger than the number of teeth of the output side sun gear 113. The rotation shaft 111 is provided with respect to the input-side rotating body 101 so that the input-side ring gear 103 and each of the input-side planetary gears 10 are connected.
6 and the output side rotating body 102, the output side ring gear 104 and each output side planetary gear 1
07 is supported.

The carrier 105 thus configured is
The input side and output side planetary gears 106 and 107 supported by the first member 108 and the input side and output side planetary gears 106 and 107 supported by the second member 109 form the input side ring gear 103 and the input side. It is assembled so as to be in close contact with the sun gear 112. At the same time, it is assembled in close contact with the output side ring gear 104 and the output side sun gear 113.

An electric motor 114 having a rotating shaft 111 as a rotating shaft is provided inside the input-side rotating body 101. The electric motor 114 is an inner rotor type DC motor, and the input side rotating body 101 is provided with a stator core 115 and an exciting coil 116 constituting a stator, and a rotor magnet 117 is fixed to the rotating shaft 111.

The electric motor 114 is connected to the input-side rotating body 101.
The rotation is controlled by an electronic control unit (not shown) based on the rotational positions of the (steering shaft) and the output-side rotating body 102 (output shaft). When the steering angle of the output-side rotator 102 is one-to-one with respect to the steering angle of the input-side rotator 101, the electronic control unit controls the electric motor so that the rotation shaft 111 does not rotate relative to the input-side rotator 101. Control. When the steering angle of the output-side rotator 102 with respect to the steering angle of the input-side rotator 101 is made larger, the rotation shaft 111 is rotated when the input-side rotator 101 rotates.
The electric motor is controlled so as to rotate relatively faster in the same direction. Conversely, when the steering angle of the output-side rotator 102 with respect to the steering angle of the input-side rotator 101 is made smaller, the rotation shaft 111 is rotated when the input-side rotator 101 rotates.
The electric motor is controlled so as to rotate relatively faster in the reverse direction.

Next, the operation of the present embodiment configured as described above will be described. When the input-side rotating body 101 rotates with steering, the steering device 100 rotates the rotating shaft 11.
The relative rotation speed of the first rotating body 101 with respect to the input side is controlled by the electric motor 114.

At this time, the rotation shaft 111 is
In a state where the rotation is controlled so as not to rotate relative to 01, the input-side rotating body 1
The rotation of No. 01 is output from the output side rotating body 102 at the rotation ratio “1”.

[0097] In the steering device 100, when the electric motor 114 is controlled so that the rotating shaft 111 rotates relative to the input-side rotator 101, the input-side rotator 1
01, the rotation axis 11 with respect to the input-side rotator 101
The rotation obtained by adding the rotation based on the relative rotation of No. 1 is output from the output side rotator 102.

When the rotating shaft 111 is driven to rotate relative to the input rotary body 101 in the same direction with respect to the input rotary body 101, the steering apparatus 100 controls the input rotary body 10 according to the steering.
One rotation is output from the output side rotating body 102 at a rotation ratio larger than the rotation ratio “1”. At this time, the steering device 100
Is output from the output-side rotator 102 at a higher rotation ratio as the relative rotation speed of the rotation shaft 111 with respect to the input-side rotator 101 increases. Therefore, depending on the vehicle situation,
The rotation axis 1 is set with respect to the rotation of the input side rotator 101 due to steering.
When the electric motor 114 is controlled such that the motor 11 rotates relatively at a higher relative speed in the same direction, the steering angle of the steered wheels with respect to the steering angle of the steering wheel is increased.

On the contrary, the steering device 100 is
Is driven to rotate relative to the input-side rotator 101 in the opposite direction, the rotation of the input-side rotator 101 in response to the steering is changed to the output-side rotation at a rotation ratio smaller than the rotation ratio “1”. Output from body 102. At this time, the steering device 100 rotates the rotating shaft 111 with respect to the input-side rotating body 101.
As the relative rotation speed in the reverse direction is higher, the output is output from the output side rotator 102 at a smaller rotation ratio. Therefore,
When the electric motor 114 is controlled such that the rotating shaft 111 relatively rotates at a relatively higher relative speed in the reverse direction with respect to the rotation of the input-side rotator 101 due to the steering, the steering angle of the steering wheel is changed. Reduce the steering angle of the steered wheels.

According to the present embodiment described in detail above, (1), (2), (5), (7),
The respective effects described in (9) can be obtained. Next, an embodiment other than the above embodiment will be described in a bulleted list.

In the first embodiment, the cylindrical rotary shaft is provided so as to be fitted to the input side rotary body. Then, a part of the output side rotating body is provided so as to include the input side sun gear. Further, the output side ring gear is provided on the input side rotating body side in the axial direction relative to the input side ring gear, and the output side sun gear is provided on the input side rotating body side in the axial direction relative to the input side sun gear. In this case, the electric motor having the rotating shaft as the rotating shaft is arranged on the input side of the two-stage planetary gear mechanism.

In the first embodiment, the electric motor is
Instead of being integrated with the steering device, the steering device may be provided with its own output shaft and fixed to the inner peripheral surface of the fixed case. In this case, for example, the gear fixed to the output shaft is meshed with the gear fixed to fit on the fixed rotary shaft, and the rotary shaft is driven to rotate.

Hereinafter, the technical ideas grasped from each of the above embodiments will be described together with their effects. (1) In the invention as set forth in claim 5, the input side planetary gears and the output side planetary gears are respectively provided at substantially equal angular intervals of six each, and the biasing means is provided with six input side planetary gears. Of the three output planetary gears and the remaining three are rotated in opposite directions, and three of the six output planetary gears and the remaining three are rotated in opposite directions. A steering device for a vehicle, characterized in that the steering device is energized so as to perform the operation.

According to such a configuration, the carrier is supported by the rotating bodies of the input side and the rotating side of the output side in a state in which the rotating axes of the carriers are better coincident with each other. (2) The vehicle steering system according to any one of claims 2 to 7, wherein the electric motor is a brushless motor. According to such a configuration, it is sufficient to supply power to the stator, so that the structure for supplying power becomes simpler.

(3) The vehicle steering system according to (2), wherein the brushless motor is of an inner rotor type. According to such a configuration, since the inertia is small and the controllability is excellent, more advanced control such as increasing the rotation ratio as the steering angle of the steering wheel is increased can be easily performed.

[0106]

According to the first to seventh aspects of the present invention, a larger torque from the driving member to the output member by the electric motor can be obtained without increasing the axial size or the outer diameter of the rotation ratio variable mechanism. Ratio can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a main part of a steering device according to a first embodiment.

FIG. 2 is a schematic side view of the same.

FIG. 3 is a schematic cross-sectional view of the input side portion.

FIG. 4 is a schematic cross-sectional view including a connecting portion between a steering shaft and an input-side rotating body.

FIG. 5 is a schematic sectional view of a main part including a carrier and a clutch.

FIG. 6 is a schematic front view of a carrier.

FIG. 7 is a schematic side view of the same.

FIG. 8 is a schematic sectional view of a steering device according to a second embodiment.

FIG. 9 is a schematic sectional view of a conventional steering device.

FIG. 10 is a schematic sectional view of the same.

[Explanation of symbols]

10: steering device, 11: case body as non-rotating part, 1
2. Steering shaft as rotation transmission shaft,
13. Same output shaft, 40 ... Rotation ratio variable mechanism, 4
DESCRIPTION OF SYMBOLS 1 ... Input side rotating body, 42 ... Output side rotating body, 43 ... Rotating shaft body, 44 ... Carrier, 52 ... Input side ring gear, 62 ...
Output ring gear, 68: rotor magnet as rotor, 70: input sun gear, 71: output sun gear, 74: input planetary gear, 75: output planetary gear, 7
6 First member constituting urging means, 77 Same second member, 78 Same support shaft, 79 Same snap ring, 84 Electric control clutch device, 96 Electric motor,
97: a stator core constituting a stator; 98: an excitation coil; 100: a steering device; 101: an input side rotating body;
102: output side rotating body, 103: input side ring gear, 1
04: output side rotating body, 105: carrier, 106: input side rotating body, 107: output side rotating body, 108: first member,
109: a second member, 111: a rotating shaft as a rotating shaft,
112: input side sun gear, 113: output side sun gear, 1
14 Electric motor.

Claims (7)

[Claims] An input-side rotating body rotatably supported; an input-side ring gear provided on the input-side rotating body; and an electric motor rotatably supported on the same axis as the input-side rotating body. A rotating shaft that can be driven to rotate relative to the input-side rotating body, an output-side rotating body rotatably supported on the same axis as the input-side rotating body, and the output-side rotating body. An output-side ring gear, an input-side sun gear provided on the rotating shaft, an output-side sun gear provided on the rotating shaft, and rotatably supported on the same axis as the rotating shaft of the rotating shaft. An input-side planetary gear rotatably supported by the carrier and meshed with the input-side ring gear and the input-side sun gear; and an output-side gear rotatably supported by the carrier. An output side planetary gear meshed with an output gear and an output side sun gear. 2. The vehicle steering system according to claim 1, further comprising the electric motor, wherein the electric motor includes a rotor having the rotating shaft as a rotating shaft. 3. A structure in which the input side rotator, the output side rotator, and the carrier are not present outside the rotor, and the electric motor includes a stator arranged outside the rotor. The vehicle steering system according to claim 2, wherein the stator is fixed to a non-rotating portion provided outside the rotor and not rotating. 4. The structure according to claim 1, wherein the rotating shaft is formed so as to include the output-side rotating body, and the input-side rotating body is formed so as to at least partially include the output-side ring gear. An input-side ring gear provided on the output-side rotating body side in an axial direction relative to the output-side ring gear; and an input-side sun gear provided on the output-side rotating body side in an axial direction relative to the output-side sun gear. The vehicle steering system according to claim 3, wherein: 5. A plurality of input planetary gears and a plurality of output planetary gears are provided, respectively, and the carrier rotates a part of the plurality of input side planetary gears and the rest thereof in directions opposite to each other. And a biasing means for biasing a part of the plurality of output-side planetary gears and the rest thereof so as to rotate in opposite directions. The vehicle steering system according to any one of claims 1 to 4. 6. An electric control clutch device according to claim 1, further comprising an electric control clutch device for connecting and fixing said rotating shaft body and said input side rotating body. Vehicle steering system. 7. The input-side rotator or the output-side rotator is a cylindrical body, and a rotation transmission shaft that cannot rotate relatively and is relatively movable in a rotation axis direction is supported inside the rotation transmission shaft. The vehicle steering device according to any one of claims 1 to 6.