JPH01233162A - Clutch device with reduction gear - Google Patents

Abstract

PURPOSE:To enable reduction of the size of a device and to facilitate incorporation, by a method wherein a holder is situated to the end part, on the inner side of a cylindrical housing, of an input shaft, and a planetary roller type reduction mechanism is located between a clutch outer wheel engaged externally of the holder and a torque transmission shaft engaged externally of an output shaft. CONSTITUTION:An input shaft 14 is supported to an end plate 12 of a cylindrical housing 11 by means of a bearing 13, a cylindrical holder 15 is located to the end part, on the housing 11 side, of the input shaft 14, and a clutch inner wheel 17 mounted to the end part of an output shaft 16 is engaged internally of the holder. The input and output shafts 14 and 16 are intercoupled through a torsion bar 41, a cylindrical torque transmission shaft 19 is engaged with the output shaft 16 through a bearing 18, and a planetary roller type reduction mechanism 22 is located between the torque transmission shaft 19 and a clutch outer wheel 21 engaged externally of the holder 15. The reduction mechanism 22 transmits revolving movement of a planetary roller 27, revolving as it is rotated through rotation exerted the torque transmission shaft 19, to the clutch inner wheel 17 having an inclines cam surface 33.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a clutch device, and particularly to a clutch device with a built-in speed reducer suitable for an electric power steering device.

[Conventional technology]

FIG. 13 shows a general configuration of an electric power steering device. In this device, when a handle 1 is rotated to the right or left, torque is generated on a handle shaft 3 due to resistance from a wheel 2. This torque is detected by a sensor 4 provided on the handle shaft 3, and a motor 6 is driven through a control device 5. The drive shaft of the motor 6 is connected to a pinion 8 of the handle shaft 3 via a reducer 7, and a rack 9 meshed with the pinion 8 of the handle shaft 3.
The wheels 2 are steered through the steering wheel. This allows the wheels to be steered with very little steering force.

[Problems to be Solved by the Invention] However, in such an electric power steering device, the control device 5. If an abnormality occurs in the drive system including the motor 6 and reducer 7 and these do not operate, the reducer 7 and motor 6 are connected to the handle shaft 3, so
There is a problem in that the manual steering force becomes excessive, making it virtually impossible to steer the vehicle.

Therefore, a method is known in which a clutch device 10 is interposed between the reducer 7 and the pinion 8.

Although an electromagnetic clutch can be used as the clutch device 10 in this case, it has the disadvantage of being too large to obtain the required transmission torque. Further, when a dog clutch is used, there are problems such as a large force being required for positioning the mesh and releasing the mesh under load.

The present invention solves the above-mentioned problems, and aims to be very suitable for being incorporated into an electric power steering device, and when being incorporated into the device,
To provide a clutch device with a built-in speed reducer which is small in size, generates little noise, and is free from hacking and crashing, which can omit the speed reducer of a motor.

[Means to solve the problem]

In order to achieve the above object, in the clutch device with a speed reducer of the present invention, the outer diameter surface of the clutch inner ring disposed inside the cylindrical retainer and the inner diameter surface of the clutch outer race disposed outside the retainer. An inclined cam surface is formed on one side, a cylindrical surface is provided on the other side, and a wedge-shaped space is formed between the cylindrical surface and the inclined cam surface that gradually narrows toward both ends in the circumferential direction. A pocket is provided at a position corresponding to the space, and two rolling elements and a spring that presses the rolling elements in opposite directions to opposite ends of the pocket in the circumferential direction are incorporated in the pocket, and Between the clutch outer ring and the clutch inner ring, a member having an inclined cam surface and a torque transmission shaft coaxially connected to the clutch inner ring are provided. A planetary roller speed reduction mechanism is provided in which a planetary roller is incorporated and the planetary roller revolves around the torque transmission shaft while rotating due to the rotation applied to the torque transmission shaft, and transmits the orbital motion of the planetary roller to a member having an inclined cam surface, The retainer and the member having the inclined cam surface are engaged with each other with a rotational clearance, and a torque setting elastic member is provided between the mutually engaged members to maintain the two members at a neutral position with respect to the rotational clearance. and in the neutral position, the pair of rolling elements housed in the pockets of the retainer do not engage with either of the pair of narrow portions in the forward and reverse rotation directions of the wedge-shaped space. be.

[Effect]

When the clutch device configured as described above is used, for example, in a power steering device, the retainer is connected to the handle shaft, and the member of the clutch outer ring and the clutch inner ring on the side having the inclined cam surface is connected to the pinion shaft. and connect the torque transmission shaft to the motor.

As a result, when the rotational torque applied to the handle shaft is less than the set torque of the torque setting elastic member, the torque setting elastic member does not bend much and is at a substantially neutral position with respect to the clearance in the rotational direction. The rolling elements housed inside are located in the wide part of the wedge-shaped space formed by the inclined cam surface and the cylindrical surface, so the clutch does not operate and the rotation of the handle shaft is transmitted to the pinion shaft via the torque setting elastic member. can do.

When the rotational torque applied to the handle shaft exceeds the set torque of the torque setting elastic member, the retainer greatly deflects the torque setting elastic member, causing the retainer to remain relative to the clutch outer ring and clutch inner ring until the rotational clearance disappears. The rolling element is caught in the narrow part of the wedge-shaped space formed by the cylindrical surface and the inclined cam surface, and the clutch is activated. At this time, the torque transmission shaft is rotated by the motor, and the rotation is transmitted to the member having a cylindrical surface among the clutch outer ring and the clutch inner ring through the planetary roller type reduction mechanism, so that the member rotates. , is transmitted from this member via the clutch to the member having the inclined cam surface. This causes the pinion shaft to rotate, allowing the wheels to be steered with very little steering force.

In the unlikely event that an abnormality occurs in the drive system including the motor and it stops operating, the rotation applied to the retainer from the handle shaft will cause the rolling elements to get caught in the wedge-shaped space between the facing surfaces of the clutch outer ring and clutch inner ring. While sliding on the cylindrical surface and disconnected from the drive system, the steering wheel operating force is transmitted to the pinion shaft via the torque setting elastic member, and the manual steering force does not become excessive.

Furthermore, when recovering from a curve, when the steering wheel is returned from the wheel side, the driver applies only enough torque to lightly slide the steering wheel with his hand, so the torque is less than the set torque.
The clutch in the drive system does not operate and must be operated manually.

Therefore, by appropriately setting the spring force of the torque setting elastic member, it is possible to automatically switch to manual operation when the torque is below the set torque, and power steering when the torque exceeds the set torque, and to prevent abnormalities from occurring in the drive system including the motor etc. Even when the vehicle is moving, the manual steering force does not become excessive, and the steering wheel is returned smoothly without giving the driver a sense of discomfort when recovering from a curve.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 12.

1 to 5 show a first embodiment of a clutch device according to the present invention.

As shown in FIG. 1, the end plate 12 of the cylindrical housing 11
A bearing 13 is attached to the input shaft 14.
is supported. A cylindrical retainer 15 is formed at the end of the human power shaft 14 located inside the housing 11, and a clutch inner ring 17 provided at the end of the output shaft 16 is fitted inside the retainer 15. ing.

The output shaft 16 is disposed coaxially with the input shaft 14, and the cylindrical torque transmission shaft 1S rotatably fitted to the output shaft 16 via a bearing 18 is a bearing attached to the inner diameter surface of the housing 11. It is rotatably supported by 2o.

Between the torque transmission shaft 19 and the clutch outer ring 21 fitted on the outside of the retainer 15, there is a planetary roller deceleration mechanism 22 that decelerates the rotation transmitted to the torque transmission shaft 19 and transmits it to the clutch outer ring 21. It is provided.

'iFi star roller two deceleration mechanism 22 is shown in FIGS. 1 and 2.
As shown in the figure, a first sun roller 23 is provided at the end of the torque transmission shaft 19 located inside the housing 11;
A cylindrical rolling element retainer 25 is provided between the sun roller 23 and the first inner roller 24 which is prevented from rotating with respect to the housing 11.
and a plurality of pockets 26 provided in the retainer 25.
The first planetary rollers 27 are stored in the respective first planetary rollers 27 .
is brought into pressure contact with the inner diameter surface of the first inner roller 24 and the outer diameter surface of the sun roller 23.

Further, the rolling element holder 25 is provided with a second sun roller 28 that is rotatable with respect to the output shaft 16, and this second sun roller 28 and a second inner roller 29 that is prevented from rotating with respect to the housing 11. The end of the clutch outer ring 21 is arranged between the clutch outer ring 21, the second planetary roller 31 is housed in a plurality of pockets 30 provided in the circumferential direction of the clutch outer ring 21, and
The planetary roller 31 is brought into pressure contact with the outer diameter surface of the second sun roller 28 and the inner diameter surface of the second inner roller 29.

With the above configuration, when a rotational force is applied to the torque transmission shaft 19, the first sun roller 23 and the first inner roller 24
The first planetary roller 27 rotates between the
It revolves around the sun roller 23, and the rolling element holder 25 rotates due to the revolution. Further, due to the rotation of the retainer 25, the second planetary roller 31 rotates and revolves between the second sun roller 28 and the second inner roller 29, and the clutch outer ring 21 rotates due to the revolution.

Therefore, the rotation of the torque transmission shaft 19 can be decelerated and transmitted to the clutch outer ring 21.

The planetary roller type speed reducer is arranged between the first sun roller 23, the first inner roller 24, and the first planetary roller 27, and between the second sun roller 28, the second inner roller 29, and the second planetary roller 31.
Because it is necessary to generate a high normal force between the two rollers and transmit power using the frictional force, the first planetary roller 27 and the second planetary roller 31 are designed with a large interference between the sun roller and the inner roller. insert. In its incorporation,
It is possible to employ a method of forcefully press-fitting or a method of so-called hot fitting in which the inner roller is heated and inserted by thermal expansion. In this case, since the first inner roller 24 and the second inner roller 29 are deformed in the radial direction due to the inclusion of the planetary roller, there is a gap between the first inner roller 24 and the second inner roller 29 and the housing 11 due to the deformation of the inner roller. It is preferable to form a radial gap corresponding to the amount or provide an elastic body.

In the case of the embodiment, the rotation of the torque transmission shaft 19 is decelerated in two stages and transmitted to the clutch outer ring 21, but the number of deceleration stages is arbitrary.

As shown in FIG. 3, the clutch outer ring 21 has an inner periphery formed into a cylindrical surface 32, while a plurality of inclined cam surfaces 33 are provided on the outer periphery of the clutch inner ring 17 at equal intervals in the circumferential direction. There is.

Two rolling bodies 35, 35' are installed in the wedge-shaped space 34 formed by the cylindrical surface 32 and each inclined cam surface 33. This pair of rolling elements 35, 35' is installed in a pocket 36 formed in the retainer 15. Also, pocket 3
6, two rolling elements 35 and 35' are placed in the pocket 36.
A spring 37 is incorporated which presses against the opposite ends of the.

The retainer 15 of the input shaft 14 and the clutch inner ring 17 are connected to the pin 3
8. That is, as shown in FIG. 3, a pin 38 is provided protruding from the outer periphery of the clutch inner ring 17, and the pin 38 is inserted into a fitting hole 39 formed in the retainer 15. A rotational clearance A is formed between the fitting hole 39 and the pin 38.

Axial holes 40, 40' are formed in the opposing end surfaces of the input shaft 14 and output shaft 16, and both ends of a torsion bar 41 as a torque setting elastic member are inserted and fixed into the holes 40, 40'. The spring force of the torsion bar 41 holds the pin 38 in the neutral position of the fitting hole 39. In the neutral position, the rolling elements 35, 35' do not engage with any of the narrow portions located at both ends of the wedge-shaped space 34 in the forward and reverse rotation directions.

Here, the spring force of the torsion bar 41 is such that when a rotational force of a certain torque or more is applied to the input shaft 14, the torsion bar 41 is twisted until the rotational direction clearance A disappears, and the retainer 15 and the clutch inner ring 17 are connected to the pin 38. It has been decided to engage through.

The clutch device shown in the first embodiment has the above structure, and when this clutch device is used in an electric power steering device, as shown in FIG. The shaft 54 of the pinion 53 that meshes with the rack 52 is connected to the output shaft 16.

−12= Also, a detection sensor 5 that detects twisting of the handle shaft 51
5 is provided, and the rotation of a motor 57 driven by this detection sensor 55 through a control device 56 is transmitted to the torque transmission shaft 19 via a torque transmission mechanism 58 such as a gear transmission mechanism.

Now, when the handle 50 is rotated and a rotational force is applied to the retainer 15 of the input shaft 14 in the left direction in FIG. Bar 41 has less twist,
Since the retainer 15 does not rotate much relative to the clutch inner ring 17, the rolling elements 35, 35' do not get caught in the narrow part of the wedge-shaped space 34, and the clutch does not operate.

Therefore, when the steering wheel operating force is small, there is no transmission of rotational force from the clutch outer ring 21 to the clutch inner ring 17.
The handle will be operated manually.

When the steering wheel operating force increases and exceeds the set torque of the torsion bar 41, the torsion bar 41 twists and the retainer 15 rotates relative to the clutch inner ring 17 until there is no clearance in the rotational direction, and the retainer Of the pair of rolling elements 35 and 35' accommodated in the 15 pockets 36, the left rolling element 35 is pushed into the wedge-shaped space 3 by the spring 37.
4, and engages the clutch (see Figure 5). On the other hand, when the operating force is transmitted to the wheels, torque is generated on the handle shaft 51 due to resistance from the wheels, and this torque is detected by the sensor 55 provided on the handle shaft 51 and drives the motor 57 through the control device 56. . The motor 5
7 is transmitted to the torque transmission shaft 19, decelerated by the planetary roller type reduction mechanism 22, and transmitted to the clutch outer ring 21.

At this time, since the clutch is already in operation, the rotation of the motor 57 is transmitted from the clutch outer ring 21 to the clutch inner ring 17 via the rolling elements 35, and then via the output shaft 16, pinion shaft 54, pinion 53, and rack 52. is transmitted to the wheels.

In this way, when the steering force exceeds the set torque, the system switches to power steering, and the wheels can be steered with a very small steering force.

In the unlikely event that an abnormality occurs in the drive system including the control device 56 and the motor 57 and these do not operate, when the handle 50 is operated, the retainer 15 connected to the handle shaft 51 is rotated. The cage 15 is rotated relative to the clutch inner ring 17 in the left direction, and the rolling elements 35 are pressed against the narrow part of the wedge-shaped space 34 (see FIG. 5).
5, the clutch does not operate and the rolling elements slide on the cylindrical surface 32 of the clutch outer ring 21.

Therefore, from the retainer 15 to the pin 38, the clutch inner ring 1
7. Manual operating force is transmitted to the wheels via the pinion shaft 54, pinion 53, and rack 52, and is disconnected from the drive system, so manual steering force does not become excessive.

Furthermore, the operation when the handle is returned from the wheel side when the drive system does not operate will be explained.

When recovering from a curve, force is transmitted from the wheels to the rack 52, pinion 53, pinion shaft 54, and clutch inner ring 17. In response to this steering wheel return force, the driver applies only enough torque to lightly slide the steering wheel with his hand.
The torque is less than the set torque of the torsion bar 41. In this case, since the retainer 15 does not rotate much relative to the clutch inner ring 17, the rolling elements 35 and 35' accommodated in the pockets 36 of the retainer 15 are not pressed against the narrow part of the wedge-shaped space 34. do not have. Therefore, the clutch does not operate, and the retainer 15 and the handle 50 connected thereto are returned in a state where the clutch inner race 17 is disconnected from the clutch outer race 21 (unrotatable).

Therefore, when recovering from a curve, the steering wheel can be returned smoothly without causing any discomfort to the driver.

7 and 8 show a second embodiment of the invention. This clutch device consists of a pin 38 protruding from the clutch inner ring 17 and a fitting hole 3 formed in the retainer 15 of the input shaft.
The pin 38 is held at a neutral position with a rotational clearance A between the pin 38 and the pin 38 via a pair of I/luke setting springs 41', 41'.

Here, the spring force of the torque setting spring 41' is such that when an operating force above a certain level is applied to the handle shaft 51 as shown in the sixth article, the torque setting spring 41' contracts until the rotational direction clearance A disappears, and the retainer 15 and the clutch inner ring 17 are determined to engage with each other via a pin 38.

Further, a protruding shaft 42 is provided on the end face of the clutch inner ring 17, and the protruding shaft 42 is connected to a hole 42 formed in the end face of the human power shaft 14.
, and is rotatably supported by a bearing 44. The other configurations and operations are the same as those in the first embodiment, so their explanations will be omitted.

FIG. 9 shows a third embodiment of the present invention, in which a leaf spring 41'' is used in place of the torsion bar 41 used in the first embodiment.

10 to 12 show a fourth embodiment of the clutch device according to the present invention. In this clutch device,
Retainer 15, clutch inner ring 17, and clutch outer ring 21
is disposed outside the housing 11, and a cylindrical portion 16' provided on the clutch inner ring 17 is inserted inside the housing 11 and rotatably supported by a bearing 45.

In addition, the input shaft 14 of the retainer 15, the clutch outer ring 21, the clutch inner ring 17, and the clutch outer ring 21 are connected to bearings 46.4.
7, and is relatively rotatably supported.

Further, a cylindrical surface 32' is provided on the outer diameter surface of the clutch inner ring 17, and an inclined cam surface 33 is provided on the inner diameter surface of the clutch outer ring 21.
' is formed, and the inclined cam surface and cylindrical surface are arranged in the opposite direction to those in the first embodiment.

Further, a pin 38' is provided on the inner diameter surface of the clutch outer ring 21, and the tip of the pin 38' is inserted into a fitting hole 39 formed in the retainer 15 with a rotational clearance A. The input shaft 14 of the retainer 15 and the clutch outer ring 21 are connected to each other by a rod 41'' as a torque setting elastic member, and the pin 38' is held at a neutral position in the fitting hole 39 by the rod 41''. .

The torque transmission shaft 19' rotated by the motor is formed of a shaft material, and the rotation applied to the torque transmission shaft 19' is transmitted to the clutch inner ring 17 via the planetary roller second reduction mechanism 22'.

When this clutch device is incorporated into an electric power steering device, the input shaft 14 of the retainer 15 is connected to the knob/torque shaft, the torque transmission shaft 19' is connected to the motor, and further,
The teeth 48 provided on the outer periphery of the clutch outer ring 21 are directly engaged with the rank member, or the teeth 48 are used to rotate the pinion shaft.

〔Effect of the invention〕

Since the present invention has the above configuration, the following effects can be obtained.

(a) When the torque is less than the set torque, the rotational torque is transmitted from the retainer to the clutch inner ring and clutch outer ring, which are members with inclined cam surfaces, and when the torque exceeds the set torque of 1 - 1 to 2 inputs of the torque transmission shaft can be mechanically switched without external control, and the part 4 has an inclined cam surface.
This enables the clutch device to transmit data to the vehicle.

(b) Since the retainer is connected to the member having the inclined cam surface by a mechanical engagement structure, the reliability of transmission is high.

(c) When the wood clutch device is used in electric power steering, it has a simple configuration using the setting spring force of the torque setting elastic member, and when the nozzle operating force is less than the set torque, manual operation is performed, and the setting When torque is exceeded, it can automatically switch to power steering.

(d) Since it has a built-in planetary roller type reduction mechanism, a reduction gear in the motor drive system can be omitted.Moreover, since the reduction mechanism incorporates the planetary rollers with a negative fit clearance, it is possible to omit the reduction gear in the motor drive system. There is no hacklash like with gears, the rotation is quiet, and there is no noise.

(E) Gear reduction gears may be damaged if a load exceeding the limit is applied or an impact force is applied, but in the case of an M-star roller type reduction gear, there is a risk of damage if excessive torque is applied. It is safe because slipping occurs.

[Brief explanation of the drawing]

1 is a longitudinal sectional view of a clutch device according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along line Tl-11 in FIG. 1, and FIG. 4 is a partially enlarged cross-sectional view of FIG. 3, FIG. 5 is a partially enlarged cross-sectional view for explaining the operation, and FIG. A schematic diagram of the state in which it is used in an electric power steering device, FIG. 7 is a longitudinal cross-sectional view showing the second embodiment, FIG. 8 is a partially enlarged cross-sectional view of FIG. 7, and FIG. 9 is a third embodiment. 10 is a vertical sectional view showing the fourth embodiment, FIG. 11 is a sectional view taken along the line X[-XI wA in FIG. FIG. 13, a sectional view taken along the line -■, is a diagram showing a conventional electric power steering device. 15... Cage, 17... Clamp punch inner ring, 19... Lux transmission shaft, 21...
...Kura Nochi outer ring, 22... Planetary roller type reduction mechanism, 32.32'... Cylindrical surface, 33.33'... Inclined cam surface, 34...・・・
・Wedge-shaped space, 35.35'...Rolling element, 3
6...Pocket, 38...Bin, 39...Fitting hole, 41...Torsion no.\-141'...Torque setting spring, 41″・・・・・・Plate spring, 41″′・・・・・・
Rod, A...Rotational clearance. Patent applicant: NCH NTOYO HAIRING CO., LTD. Agent: Kama 1) Written by Nie 23=

Claims (1)

[Claims] An inclined cam surface is formed on one of the outer diameter surface of the clutch inner ring placed inside the cylindrical retainer and the inner diameter surface of the clutch outer ring placed outside the retainer, and a cylindrical surface is provided on the other side. A wedge-shaped space is formed between the cam surfaces that gradually narrows toward both ends in the circumferential direction, a pocket is provided in the retainer at a position corresponding to the wedge-shaped space, and two rolling elements are placed in the pocket, A spring that presses the rolling elements in opposite directions to opposite ends of the pocket in the circumferential direction is incorporated, and among the clutch outer ring and the clutch inner ring,
Between the member having the inclined cam surface and the torque transmission shaft arranged coaxially with respect to the clutch inner ring, a planetary roller is installed between the torque transmission shaft and an inner roller arranged outside the torque transmission shaft and prevented from rotating. A planetary roller speed reduction mechanism is provided that transmits the orbital motion of a planetary roller that revolves around the torque transmission shaft while rotating due to the rotation applied to the transmission shaft to a member having an inclined cam surface, the retainer and the inclined cam surface A torque setting elastic member is provided between the mutually engaged members to hold both members at a neutral position with respect to the rotational clearance, and a torque setting elastic member is provided between the mutually engaged members with a rotational clearance. A clutch device with a speed reducer, characterized in that a pair of rolling elements housed in a pocket of a device do not engage with either of the pair of narrow portions in the forward and reverse rotation directions of the wedge-shaped space.