JP2024044977A - Torque sensor device and steering device - Google Patents

Abstract

[Problem] To suppress operating noise by applying a preload to a bearing while suppressing an increase in weight. [Solution] A rotor includes a stator fixed to an output shaft, a housing having the output shaft and the stator disposed inside, a bearing supporting the output shaft for rotation relative to the housing, and a retainer disposed between the housing and the bearing, wherein the bearing has an outer ring, an inner ring, and a plurality of rolling elements disposed between the outer ring and the inner ring, the retainer having a cylindrical portion formed in a cylindrical shape, an inner peripheral surface of the cylindrical portion facing an outer peripheral surface of the bearing, and an outer peripheral surface of the cylindrical portion facing an inner peripheral surface of the housing, the cylindrical portion being attached to the bearing such that movement of the bearing relative to the outer ring in the axial direction is restricted, and the housing abuts against a surface of the retainer that faces the axial direction of the cylindrical portion. [Selected figure] Figure 5

Description

The present disclosure relates to a torque sensor device and a steering device.

In a torque sensor device that detects torque applied to a rotating shaft of a steering device, a bearing is disposed between a housing and the rotating shaft to rotatably support the rotating shaft with respect to the housing. As a bearing that rotatably supports a rotating shaft, a so-called rolling bearing, in which rolling elements are arranged between an outer ring and an inner ring, is used, for example. However, in rolling bearings, there is a gap between the outer ring or inner ring and the rolling elements, so when a rotating shaft is supported by a rolling bearing, the rolling elements collide with the outer ring or inner ring due to vibrations while the vehicle is running, producing noise. There are things to do.

For example, in the electric power steering device described in Patent Document 1, an elastic plate is used to apply axial preload to the rolling elements. In the power steering device described in Patent Document 2, the upper end face of the outer ring of the rolling bearing is brought into contact with a step in the housing, and the lower end face of the inner ring is brought into contact with the upper end face of the core metal of the worm wheel.

JP 2007-196932 A JP 2002-362387 A

However, as in Patent Documents 1 and 2, the housing is abutted against the outer circumference of the outer ring of the bearing, so it is necessary to use a bearing with an outer diameter that matches the shape of the housing. In this case, it is necessary to select a large bearing that matches the shape of the housing relative to the size of the bearing required for the load that the bearing will bear, which may result in an increase in the weight of the bearing.

The present disclosure has been made in view of the above, and aims to provide a torque sensor device and a steering device that can apply preload to a bearing and suppress operating noise while suppressing an increase in weight. .

The torque sensor device of the present disclosure includes a stator fixed to a shaft, a cylindrical magnet placed opposite the stator, a housing in which the shaft, the stator, and the magnet are arranged, and the shaft a bearing rotatably supported with respect to the housing, and a retainer interposed between the housing and the bearing, the bearing having an outer ring, an inner ring, and a ring between the outer ring and the inner ring. the retainer has a cylindrical portion formed in a cylindrical shape, an inner circumferential surface of the cylindrical portion faces an outer circumferential surface of the bearing, and an outer circumferential surface of the cylindrical portion The cylindrical portion is attached to the bearing such that movement in the axial direction of the bearing relative to the outer ring is restricted, and the housing faces the inner circumferential surface of the cylindrical portion of the retainer. Abuts on the surface facing.

According to this configuration, the retainer interposed between the housing and the bearing has a cylindrical portion, and the cylindrical portion of the retainer is attached to the bearing while axial movement relative to the outer ring of the bearing is restricted. The housing also abuts against the surface of the cylindrical portion of the retainer facing the axial direction. This allows the retainer to apply the pressing force applied from the housing to the retainer to the bearing, and preload the bearing. Therefore, even if vibrations during vehicle travel are transmitted to the bearing, collisions between the outer ring or inner ring of the bearing and the rolling elements can be suppressed, and operating noise caused by these collisions can be suppressed. In addition, since a preload is applied to the bearing by interposing the retainer between the housing and the bearing, a bearing smaller than the inner peripheral surface of the housing can be selected, and preload can be applied to the bearing without increasing the weight of the bearing. As a result, it is possible to apply preload to the bearing and suppress operating noise while suppressing an increase in weight.

In a desirable form, the retainer includes an inner extension part extending inward in the radial direction of the cylindrical part from an end in the axial direction of the cylindrical part, and a side on which the inner extension part is arranged in the axial direction of the cylindrical part. an outer extension extending outward in the radial direction of the cylindrical portion from the end on the opposite side, and a surface of the inner extension on the side where the cylindrical portion is located in the axial direction of the cylindrical portion is of the bearing. By coming into contact with an end surface of the outer ring in the axial direction, the cylindrical part is attached to the bearing with movement of the bearing relative to the outer ring in the axial direction being restricted, and the cylindrical part is positioned in the axial direction of the cylindrical part. The surface of the outer extension on the side abuts the retainer abutting portion, which is a portion of the housing facing in the axial direction of the cylindrical portion, so that the housing faces in the axial direction of the cylindrical portion in the retainer. come into contact with the surface.

According to this configuration, the retainer has a cylindrical part, an outer extension part, and an inner extension part, the outer extension part contacts the retainer abutting part of the housing, and the inner extension part is an end face of the outer ring in the axial direction of the bearing. comes into contact with. As a result, the housing comes into contact with the axially facing surface of the cylindrical portion of the retainer, and the retainer is attached to the bearing with its movement in the axial direction relative to the outer ring of the bearing restricted, so that the retainer is attached to the outer extension from the housing. A pressing force can be applied to the bearing from the inner extension, and a preload can be applied to the bearing. Therefore, even if vibrations are transmitted to the bearing while the vehicle is running, collisions between the outer ring and rolling elements of the bearing and collisions between the inner ring and rolling elements can be suppressed, and the operating noise caused by these collisions can be suppressed. be able to. As a result, it is possible to apply preload to the bearing and suppress operating noise while suppressing an increase in weight.

Preferably, the housing applies preload in the axial direction of the bearing from the retainer to the outer ring of the bearing by the retainer abutting portion abutting the outer extension portion of the retainer.

With this configuration, the housing applies a preload in the axial direction of the bearing from the retainer to the outer ring of the bearing by the retainer abutting the retainer abutment portion against the outer extension portion of the retainer, so that preload can be applied to the bearing with a simple configuration. This makes it possible to reduce manufacturing costs when providing a structure for applying preload to the bearing. As a result, it is possible to apply preload to the bearing and suppress operating noise while preventing an increase in manufacturing costs.

In a desirable form, the retainer has an inner extension portion extending inward in the radial direction of the cylindrical portion from an end in the axial direction of the cylindrical portion, and a side on which the cylindrical portion is located in the axial direction of the cylindrical portion. Since the surface of the inner extension portion contacts the end surface of the outer ring in the axial direction of the bearing, the cylindrical portion is attached to the bearing with movement in the axial direction of the bearing relative to the outer ring being restricted, and the housing is , a large diameter portion whose inner circumferential surface faces the outer circumferential surface of the cylindrical portion of the retainer, a small diameter portion whose inner diameter is smaller than the inner diameter of the large diameter portion, and connecting the large diameter portion and the small diameter portion; and a connecting portion facing the end surface of the outer ring in the axial direction of the bearing, and the connecting portion comes into contact with an end of the cylindrical portion of the retainer on the side where the inner extension portion is located in the axial direction, The housing contacts an axially facing surface of the cylindrical portion of the retainer.

According to this configuration, the retainer has an inner extension, and the inner extension abuts against the end face of the outer ring, so that the cylindrical part of the retainer is attached to the bearing while being restricted from moving in the axial direction relative to the outer ring. The housing has a step portion having a large diameter portion, a small diameter portion, and a connecting portion, and the connecting portion abuts against the end of the retainer on the side where the inner extension is located, so that the housing abuts against the surface of the cylindrical part of the retainer facing the axial direction. This allows the pressing force applied from the housing to the end of the retainer on the side where the inner extension is located to be applied from the inner extension to the bearing, and a preload can be applied to the bearing. Therefore, even if vibrations during vehicle travel are transmitted to the bearing, collisions between the outer ring and the rolling elements of the bearing and between the inner ring and the rolling elements can be suppressed, and operating noise caused by these collisions can be suppressed. As a result, it is possible to suppress operating noise by applying a preload to the bearing while suppressing an increase in weight.

In a desirable form, the housing is configured such that the connecting portion contacts an end of the retainer on the side where the inner extension portion in the axial direction of the cylindrical portion is located, so that the housing is connected to the outer ring of the bearing from the retainer. Applying an axial preload to the bearing.

According to this configuration, the housing applies an axial preload from the retainer to the outer ring of the bearing when the connecting portion comes into contact with the end of the retainer on the side where the inner extension portion is located. Even if the bearing size is small, a preload can be applied to the bearing. As a result, when the size of the bearing is small compared to the housing, it is possible to apply preload to the bearing without using a larger bearing to match the housing, and with the bearing still being smaller in size compared to the housing. can. Therefore, manufacturing costs can be reduced when providing a structure that applies preload to the bearing. As a result, it is possible to apply preload to the bearing and suppress operational noise while suppressing an increase in manufacturing costs.

Preferably, the inner diameter of the inner extension of the retainer is smaller than the outer diameter of the outer ring and larger than the outer diameter of the inner ring.

According to this configuration, the inner diameter of the inner extension of the retainer is smaller than the outer diameter of the outer ring of the bearing and larger than the outer diameter of the inner ring, so that relative rotation between the outer ring and the inner ring is not inhibited by the inner extension, An axial pressing force can be applied from the extension to the outer ring. Thereby, the retainer can apply preload to the bearing while suppressing an increase in resistance when the outer ring and the inner ring of the bearing rotate relative to each other. As a result, while suppressing an increase in resistance when the shaft rotates with respect to the housing, it is possible to apply preload to the bearing and suppress operational noise.

Preferably, the cylindrical portion is attached to the bearing by being press-fitted into the outer ring, thereby restricting movement of the bearing in the axial direction with respect to the outer ring.

According to this configuration, the retainer is attached to the bearing by having the cylindrical portion press-fitted into the outer ring of the bearing, thereby restricting movement of the bearing in the axial direction relative to the outer ring. It can be installed in a state where movement in the axial direction is restricted. Therefore, when applying preload to the bearing by bringing the connecting portion of the stepped portion of the housing into contact with the end of the retainer, the preload can be applied to the bearing with a simple configuration. As a result, it is possible to apply preload to the bearing and suppress operational noise while suppressing an increase in manufacturing costs.

In a desirable form, the cylindrical portion, when press-fitted into the outer ring, has a distance between one end of the cylindrical portion in the axial direction and an end of the outer ring, and the other end of the cylindrical portion in the axial direction. and the distance between the outer ring and the end of the outer ring are different from each other.

According to this configuration, by making the distance between the end of the cylindrical part and the end of the outer ring different on both sides in the axial direction, the connection part of the housing is brought into contact with the bearing in which the cylindrical part is press-fitted. The end of the cylindrical portion on the side can be easily grasped. Therefore, when assembling the bearing into which the cylindrical portion is press-fitted onto the shaft, it is possible to avoid making a mistake in the direction of assembling. Thereby, it is possible to appropriately apply preload to the bearing, and operational noise can be suppressed.

As a desirable form, the outer diameter of the bearing is equal to or less than the outer diameter of the stator.

According to this configuration, since the outer diameter of the bearing is equal to or less than the outer diameter of the stator, the bearing can be made smaller and the weight of the bearing can be reduced. As a result, it is possible to apply preload to the bearing and suppress operating noise while suppressing an increase in weight.

In a preferred embodiment, the outer diameter of the cylindrical portion of the retainer is greater than the outer diameter of the stator.

According to this configuration, since the outer diameter of the cylindrical portion of the retainer is larger than the outer diameter of the stator, the inner diameter of the housing in which the retainer faces the inner peripheral surface can be made larger than the outer diameter of the stator. Thereby, the housing can be assembled to the shaft without causing the housing to interfere with the stator. As a result, while making it possible to assemble the housing to the shaft, a preload can be applied from the retainer to the bearing by the pressing force applied to the retainer from the retainer abutting portion of the housing.

The steering device disclosed herein includes a steering shaft having an input shaft, an output shaft, and a torsion bar disposed inside the input shaft and the output shaft to connect the input shaft and the output shaft, a stator attached to either the input shaft or the output shaft, a cylindrical magnet attached to the other of the input shaft or the output shaft and disposed facing the stator, a first housing in which the steering shaft, the stator, and the magnet are disposed, a first bearing that supports the output shaft rotatably relative to the first housing, a retainer interposed between the first housing and the first bearing, an electric motor that generates auxiliary steering torque, a worm wheel that is fixed to the output shaft and transmits the auxiliary steering torque generated by the electric motor to the output shaft, and a worm wheel that is fixed to the output shaft and transmits the auxiliary steering torque generated by the electric motor to the output shaft. The second housing is located near the output shaft and connected to the first housing, and has the steering shaft and the worm wheel disposed inside. A second bearing is disposed on the opposite side of the worm wheel in the axial direction of the steering shaft to the side where the first bearing is located, and supports the output shaft rotatably relative to the second housing. The first bearing has an outer ring, an inner ring, and a plurality of rolling elements disposed between the outer ring and the inner ring. The retainer has a cylindrical portion formed in a cylindrical shape, the inner surface of the cylindrical portion faces the outer surface of the first bearing, and the outer surface of the cylindrical portion faces the inner surface of the first housing. The cylindrical portion is attached to the first bearing such that the axial movement of the first bearing relative to the outer ring is restricted, and the first housing abuts against the surface of the retainer facing the axial direction of the cylindrical portion.

According to this configuration, the retainer interposed between the first housing and the first bearing has a cylindrical portion, and the cylindrical portion of the retainer is attached to the first bearing while axial movement relative to the outer ring of the first bearing is restricted. The first housing abuts against the surface of the cylindrical portion of the retainer facing the axial direction. This allows the retainer to apply the pressing force applied from the first housing to the retainer to the first bearing, and to apply a preload to the first bearing. Therefore, even if vibrations during vehicle running are transmitted to the first bearing, collisions between the outer ring or inner ring of the first bearing and the rolling elements can be suppressed, and operating noise caused by these collisions can be suppressed. In addition, since a preload is applied to the first bearing by interposing the retainer between the first housing and the first bearing, a preload can be applied to the first bearing without increasing the weight of the first bearing. As a result, it is possible to apply a preload to the first bearing while suppressing an increase in weight, and to suppress operating noise.

The torque sensor device and the steering device according to the present disclosure have the effect of suppressing an increase in weight while applying preload to the bearing and suppressing operational noise.

FIG. 1 is a schematic diagram of a steering device according to a first embodiment. FIG. 2 is a sectional view of main parts of the torque sensor device according to the first embodiment. FIG. 3 is a schematic diagram for explaining an outline of a magnet, a stator, and a magnetic flux collecting yoke that the torque detection unit has. FIG. 4 is an enlarged cross-sectional view of the position where the torque detection section and bearing shown in FIG. 2 are arranged. FIG. 5 is a detailed schematic diagram of the retainer and bearing shown in FIG. 4. FIG. 6 is an explanatory diagram of how force is transmitted when applying preload from the retainer to the bearing. FIG. 7 is a schematic diagram of a torque sensor device in which a preload applying member is provided in a first housing. FIG. 8 is a schematic diagram showing a state in which the first housing of the torque sensor device shown in FIG. 7 is assembled. FIG. 9 is a schematic diagram of the torque sensor device according to the first embodiment before the first housing is assembled to the steering shaft. FIG. 10 is a schematic diagram showing a state in which the first housing is assembled to the steering shaft shown in FIG. FIG. 11 is a sectional view of a main part of a torque sensor device according to a second embodiment. FIG. 12 is a detailed schematic diagram of the retainer and bearing shown in FIG. 11. FIG. 13 is an explanatory diagram of how force is transmitted when a preload is applied from a retainer to a bearing. FIG. 14 is a schematic diagram of the torque sensor device according to the second embodiment before the first housing is assembled to the steering shaft. FIG. 15 is a schematic diagram showing a state in which the first housing is assembled to the steering shaft shown in FIG. FIG. 16 is a cross-sectional view of a main part of a torque sensor device according to the third embodiment. FIG. 17 is a detailed schematic diagram of the retainer and the bearing shown in FIG. FIG. 18 is an explanatory diagram of how force is transmitted when a preload is applied from a retainer to a bearing. FIG. 19 is an explanatory diagram showing a modified example of the torque sensor device according to the first embodiment, in which a small diameter bearing is used. FIG. 20 is an explanatory diagram showing a modified example of the torque sensor device according to the second embodiment, in which a small diameter bearing is used. FIG. 21 shows a modified example of the torque sensor device according to the second embodiment, and is an explanatory diagram of a form in which the cylindrical portion and the inner extension portion of the retainer are separated. FIG. 22 is a modification of the torque sensor device according to the third embodiment, and is an explanatory diagram showing a form in which the width of the retainer in the axial direction is different from the width of the bearing. FIG. 23 is an explanatory diagram showing a modified example of the torque sensor device according to the third embodiment, in which the cylindrical portion of the retainer is attached to the bearing using a crimped portion as well. FIG. 24 is an explanatory diagram showing an example of a method of forming the caulked portion shown in FIG. 23. FIG. 25 is an explanatory diagram showing an example of a method for forming the crimped portion shown in FIG.

The present disclosure will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to the following modes for carrying out the invention (hereinafter referred to as embodiments). Furthermore, the components in the following embodiments include those that a person skilled in the art can easily imagine, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the components disclosed in the following embodiments can be combined as appropriate.

[First embodiment]
FIG. 1 is a schematic diagram of a steering device 80 according to the first embodiment. As shown in FIG. 1, the steering device 80 includes a steering wheel 81, a torque sensor device 10, an electric motor 91, a reduction gear device 92, a universal joint 84, and an intermediate joint 84 in the order in which force applied by an operator is transmitted. It includes a shaft 85 and a universal joint 86 and is joined to a pinion shaft 87. In the following description, the direction along the central axis AX of the steering shaft 82 will be referred to as the "axial direction", and the direction intersecting (orthogonal to) the axial direction will be referred to as the "radial direction".

The torque sensor device 10 includes a steering shaft 82 and a torque detection unit 30. The steering shaft 82 includes an input shaft 82a, an output shaft 82b, and a torsion bar (see FIG. 2) 82c. The torque sensor device 10 will be described in detail later.

The intermediate shaft 85 connects the universal joint 84 and the universal joint 86. The intermediate shaft 85 has one end connected to the universal joint 84 and the other end connected to the universal joint 86. The pinion shaft 87 has one end connected to the universal joint 86 and the other end connected to the steering gear 88. The universal joint 84 and the universal joint 86 are, for example, cardan joints. Rotation of the steering shaft 82 is transmitted to the pinion shaft 87 via the intermediate shaft 85. Therefore, the intermediate shaft 85 is rotatable together with the steering shaft 82.

The steering gear 88 includes a pinion gear 88a and a rack bar 88b. The pinion gear 88a is connected to the pinion shaft 87. The rack bar 88b meshes with the pinion gear 88a. The steering gear 88 converts the rotational motion transmitted to the pinion gear 88a into linear motion by the rack bar 88b. The rack bar 88b is connected to a tie rod 89. The angle of the wheels changes as the rack bar 88b moves. In other words, the steering device 80 is a rack-and-pinion type electric power steering device.

The steering device 80 further includes an ECU (Electronic Control Unit) 90 and a vehicle speed sensor 95. Electric motor 91, vehicle speed sensor 95, and torque detection section 30 are electrically connected to ECU 90. The speed reduction device 92 is attached to the electric motor 91 . The torque detection unit 30 outputs the steering torque transmitted to the input shaft 82a to the ECU 90 through CAN (Controller Area Network) communication. Vehicle speed sensor 95 detects the running speed (vehicle speed) of the vehicle body on which steering device 80 is mounted. Vehicle speed sensor 95 is provided in the vehicle body and outputs vehicle speed to ECU 90 via CAN communication.

ECU 90 controls the operation of electric motor 91 . ECU 90 acquires signals from each of torque detection section 30 and vehicle speed sensor 95. Electric power is supplied to the ECU 90 from a power supply device 99 (for example, a vehicle-mounted battery) while an ignition switch 98 is on. The ECU 90 calculates an auxiliary steering command value based on the steering torque and vehicle speed. The ECU 90 adjusts the electric power value supplied to the electric motor 91 based on the auxiliary steering command value. The ECU 90 acquires information on the induced voltage of the electric motor 91 or information output from a resolver or the like provided in the electric motor 91. Since the ECU 90 controls the electric motor 91, the force required to operate the steering wheel 81 is reduced.

Next, the torque sensor device 10 will be explained. FIG. 2 is a sectional view of main parts of the torque sensor device 10 according to the first embodiment. As shown in FIG. 2, the torque sensor device 10 includes an input shaft 82a that is a first shaft, an output shaft 82b that is a second shaft, a torsion bar 82c, a torque detection section 30, a housing 20, It includes a retainer 50 and bearings 60 and 68. The input shaft 82a, the output shaft 82b, and the torsion bar 82c have the same central axis AX. The input shaft 82a and the output shaft 82b are connected in the axial direction, and the torsion bar 82c is arranged inside the input shaft 82a and the output shaft 82b.

The input shaft 82a is, for example, a solid shaft. The input shaft 82a is rotatable around the central axis AX. A splined shaft portion (not shown) is formed on the end of the input shaft 82a opposite to the end connected to the output shaft 82b, and the steering wheel 81 (see FIG. 1) is connected to the splined shaft portion directly or via another shaft. An insertion hole 82aa is formed on the radially inner side of the input shaft 82a, extending in the axial direction from the end connected to the output shaft 82b.

The output shaft 82b is a cylindrical member having a through hole 82ba and a connecting hole 82bb extending in the axial direction on the radially inner side. The output shaft 82b is located on the side of the input shaft 82a where the end where the insertion hole 82aa is formed is located. The output shaft 82b is rotatable in the direction around the central axis AX. The connecting hole 82bb has an inner diameter larger than that of the through hole 82ba, and is formed at a predetermined depth from the end of the output shaft 82b where the input shaft 82a is connected to the side opposite the side where the input shaft 82a is located. The through hole 82ba extends from the end of the connecting hole 82bb of the output shaft 82b toward the side opposite the side where the input shaft 82a is located. A portion near the end of the input shaft 82a is inserted into the inside of the connecting hole 82bb.

The driving force generated by the electric motor 91 (see FIG. 1) is transmitted to the output shaft 82b via the worm 93 and worm wheel 94 of the reduction gear 92. That is, the driving force generated by the electric motor 91 is transmitted to the worm wheel 94 via the worm 93, causing the worm wheel 94 to rotate. The worm 93 and the worm wheel 94 reduce the rotational speed of the driving force generated by the electric motor 91 and increase the torque.

The worm wheel 94 has a core metal portion 94a and a wheel tooth portion 94b. The core metal portion 94a is made of, for example, a metal material and is formed in a substantially annular shape. The wheel tooth portion 94b is made of, for example, a resin material, and is disposed integrally with the metal core portion 94a on the outer periphery of the metal core portion 94a. The worm wheel 94 is fixed to the output shaft 82b by press-fitting a core metal portion 94a into the output shaft 82b. The worm 93 meshes with the wheel teeth 94b of the worm wheel 94. Therefore, the reduction gear device 92 increases the torque of the driving force generated by the electric motor 91 and transmits it to the output shaft 82b, thereby providing an auxiliary steering torque to the output shaft 82b. That is, the steering device 80 according to the present embodiment is a column assist type electric power steering device in which auxiliary steering torque is applied to the steering shaft 82.

The torsion bar 82c is a solid elastic member that extends in the axial direction. One end of the torsion bar 82c in the axial direction is inserted into the insertion hole 82aa of the input shaft 82a. A through hole that penetrates in the radial direction is formed at the end of the torsion bar 82c that is inserted into the insertion hole 82aa of the input shaft 82a. In addition, a through hole passing through the input shaft 82a in the radial direction is also formed at a position where the through hole of the torsion bar 82c is formed in the axial direction. The through hole formed in the torsion bar 82c and the through hole formed in the input shaft 82a communicate with each other. A pin 100 is inserted into the through hole formed in the torsion bar 82c and the through hole formed in the input shaft 82a. As a result, the end of the torsion bar 82c that is inserted into the insertion hole 82aa of the input shaft 82a is fixed to the input shaft 82a via the pin 100.

The other end of the torsion bar 82c in the axial direction is press-fitted into a through hole 82ba formed in the output shaft 82b. Thereby, the torsion bar 82c is fixed to the output shaft 82b. That is, since one end of the torsion bar 82c is fixed to the input shaft 82a and the other end is fixed to the output shaft 82b, the input shaft 82a and the output shaft 82b are connected to each other via the torsion bar 82c. are connected.

At least a portion of the steering shaft 82 is disposed inside the housing 20. The housing 20 is the housing of the torque sensor device 10, and has a first housing 21 and a second housing 25. The first housing 21 is located closer to the input shaft 82a in the axial direction, and the second housing 25 is located closer to the output shaft 82b in the axial direction, and the first housing 21 and the second housing 25 are connected in the axial direction. The second housing 25 has a space inside for arranging the worm 93 and the worm wheel 94, and the second housing 25 is also provided as a gear box.

Bearings 60 and 68 are interposed between the housing 20 and the steering shaft 82, and the steering shaft 82 is rotatably supported by the bearings 60 and 68. The bearing 60 is provided as a first bearing that rotatably supports the output shaft 82b with respect to the first housing 21. The bearing 68 is provided as a second bearing that rotatably supports the output shaft 82b with respect to the second housing 25.

The bearing 60 and the bearing 68 are arranged on both sides of the output shaft 82b in the axial direction of the position where the worm wheel 94 is fixed. The bearing 60 is disposed on the side where the input shaft 82a is located in the axial direction with respect to the position where the core metal part 94a of the worm wheel 94 is fixed on the output shaft 82b, and the bearing 68 is located on the side where the input shaft 82a is located. It is arranged on the opposite side of the input shaft 82a in the axial direction with respect to the position where the portion 94a is fixed. That is, the bearing 68 is arranged on the opposite side of the worm wheel 94 from the side where the bearing 60 is located in the axial direction. The inner rings of the bearings 60 and 68 are in contact with the metal core 94a of the worm wheel 94 from both sides of the worm wheel 94 in the axial direction.

Note that the inner ring of the bearing 60 or the bearing 68 may have a side surface in the axial direction in contact with the output shaft 82b. That is, the portion of the output shaft 82b to which the core metal portion 94a of the worm wheel 94 is fixed is formed as a convex portion that protrudes outward in the radial direction over one circumference, and the convex portion of the output shaft 82b is When the outer diameter is larger than the inner diameter of the bearing 60 or the bearing 68, the inner ring of the bearing 60 or the bearing 68 may be in contact with the axial side surface of the convex portion of the output shaft 82b. In the bearings 60 and 68, the inner ring contacts the worm wheel 94, or the inner ring contacts the side surface of a convex portion of the output shaft 82b that protrudes outward in the radial direction over one circumference. By doing so, movement toward each other in the axial direction is restricted.

The retainer 50 is disposed between the bearing 60 and the first housing 21, among the bearings 60 and 68 that rotatably support the output shaft 82b. In other words, the retainer 50 is interposed between the first housing 21 and the bearing 60.

The torque detection unit 30 has a magnet 31, a stator 34, a magnetic flux collector yoke 41, and a circuit board 44. Of these, the magnet 31 and the stator 34 are fixed to the steering shaft 82, and the magnetic flux collector yoke 41 and the circuit board 44 are fixed to the housing 20.

FIG. 3 is a schematic diagram illustrating an overview of the magnet 31, stator 34, and magnetic flux collecting yoke 41 included in the torque detection section 30. One of the magnet 31 and the stator 34 included in the torque detection section 30 is attached to the first shaft, and the other is attached to the second shaft. In the first embodiment, the magnet 31 is attached to the input shaft 82a, which is the first shaft, and the stator 34 is attached to the output shaft 82b, which is the second shaft. Among these, the magnet 31 is formed in a substantially cylindrical shape, and is a multipolar magnet in which a plurality of N poles and S poles are alternately arranged in the circumferential direction. Note that the stator 34 and the magnet 31 can be used if the stator 34 is attached to either the input shaft 82a or the output shaft 82b, and the magnet 31 is attached to the other of the input shaft 82a or the output shaft 82b. good. If the stator 34 and the magnet 31 are attached to mutually different shafts among the input shaft 82a and the output shaft 82b, the stator 34 and the magnet 31 are a combination when attached to the input shaft 82a or the output shaft 82b. I don't care.

The stator 34 has a flange portion 35 and teeth portions 36. The flange portion 35 is formed in an annular plate shape with the thickness direction being the axial direction. The teeth portions 36 extend from the inner periphery of the annular flange portion 35 toward the axial direction of the flange portion 35, and are formed in a plate shape with the thickness direction of the plate oriented in the radial direction of the flange portion 35. In addition, the teeth portions 36 are arranged side by side in the circumferential direction of the flange portion 35 with a gap between them.

The stator 34 thus formed has a pair of stators 34, the first stator 34a and the second stator 34b, which are formed with the same shape, and the first stator 34a and the second stator 34b each have a flange portion 35 and a teeth portion 36. That is, the first stator 34a has a circular first flange portion 35a and a plurality of first teeth portions 36a, and the second stator 34b has a circular second flange portion 35b and a plurality of second teeth portions 36b. The first stator 34a and the second stator 34b are both attached to the same shaft with both flange portions 35 positioned coaxially and oriented such that the flange portions 35 are positioned in a direction away from the other stator 34, and in the first embodiment, both are attached to the output shaft 82b.

That is, the first stator 34a is arranged such that the first tooth portion 36a extends from the first flange portion 35a toward the second stator 34b, and the second stator 34b is arranged such that the second tooth portion 36b extends from the first flange portion 35a toward the second stator 34b. It is arranged so as to extend from the flange portion 35b toward the first stator 34a. At this time, since a plurality of the first teeth portions 36a and the second teeth portions 36b are provided on the first flange portion 35a and the second flange portion 35b at intervals, the first stator 34a and the second stator 34b is combined so that the teeth portion 36 of the stator 34 of the stator 34 is located in a portion where the teeth portion 36 of the other stator 34 is not located in the circumferential direction.

The magnet 31 attached to the input shaft 82a is arranged inside the first stator 34a and the second stator 34b combined in this way in the radial direction. Further, the magnet 31 and the stator 34 are arranged with their axial directions coinciding with the axial directions of the input shaft 82a and the output shaft 82b. For these reasons, the magnet 31 and the stator 34 are attached to the input shaft 82a and the output shaft 82b, with the outer circumferential surface of the magnet 31 facing the teeth portion 36 of the stator 34. Ru. By arranging the magnet 31 and the stator 34 in this positional relationship, torque is transmitted between the input shaft 82a and the output shaft 82b via the torsion bar 82c, and the input shaft 82a and the output shaft 82b are When the magnet 31 and the stator 34 rotate slightly, the magnetic flux acting on the stator 34 from the magnet 31 changes as the relative positional relationship between the magnet 31 and the stator 34 changes.

Further, near the stator 34, a magnetic flux collecting yoke 41 included in the torque detection section 30 is arranged. The magnetic flux collecting yoke 41 is a member for detecting changes in the magnetic flux acting on the stator 34 from the magnet 31, and is arranged near the flange portion 35 of the stator 34. As the stator 34, a pair of a first stator 34a and a second stator 34b is provided. A pair is provided. That is, in the magnetic flux collecting yoke 41, the first magnetic flux collecting yoke 41a is disposed near the first flange portion 35a of the first stator 34a, and the second magnetic flux collecting yoke 41a is disposed near the second flange portion 35b of the second stator 34b. A magnetic flux collecting yoke 41b is arranged.

The pair of magnetic flux collecting yokes 41 are located between the two flange portions 35 of the stator 34, and overlap the flange portions 35 of the stator 34 with a gap in the axial direction. That is, the first magnetic flux collecting yoke 41a is located near the surface side of the first flange portion 35a of the first stator 34a where the second flange portion 35b is located, and the second magnetic flux collecting yoke 41b is located near the surface side of the second flange portion 35b of the second stator 34b where the first flange portion 35a is located. In this way, by positioning the magnetic flux collecting yoke 41 near the flange portion 35, the magnetic flux collecting yoke 41 can detect changes in the magnetic flux acting on the stator 34 from the magnet 31 when the input shaft 82a and the output shaft 82b rotate slightly relative to each other.

Further, a Hall IC 43 is arranged between the two magnetic flux collecting yokes 41. The Hall IC 43 is arranged between the magnetic flux collecting yokes 41 at a position away from a portion of the magnetic flux collecting yokes 41 located near the flange portion 35 of the stator 34 . The Hall IC 43 is capable of detecting a change in magnetic flux density acting on the two magnetic flux collecting yokes 41, converting the detected change in magnetic flux density into an electrical signal, and outputting the electrical signal. Note that instead of the Hall IC, a magnetic sensor applying magnetoresistive effect or tunnel magnetoresistive effect can be used. In short, it is sufficient if the change in magnetic flux density that occurs between the magnetic flux collecting yokes 41 can be output as an electrical signal.

FIG. 4 is an enlarged sectional view of the position where the torque detection section 30 and bearings 60, 68 shown in FIG. 2 are arranged. The magnet 31 is attached to the input shaft 82a by the first sleeve 32. The first sleeve 32 is a cylindrical member, and the first sleeve 32 is attached to the input shaft 82a by press-fitting the input shaft 82a into the first sleeve 32. The magnet 31 is fixed to the outer circumferential surface of the first sleeve 32 with, for example, an adhesive, so that the magnet 31 can rotate integrally with the input shaft 82a.

The stator 34 is attached to the output shaft 82b by a second sleeve 37 and a carrier 38. The second sleeve 37 is a cylindrical member, and the second sleeve 37 is attached to the output shaft 82b by press-fitting the output shaft 82b into the second sleeve 37. The carrier 38 is a cylindrical member, and is integrally formed with the second sleeve 37 by injection molding. Therefore, when the second sleeve 37 is attached to the output shaft 82b, the carrier 38 is also attached to the output shaft 82b together with the second sleeve 37.

The carrier 38, which is attached to the output shaft 82b by the second sleeve 37, is supported by the second sleeve 37 and positioned from the output shaft 82b toward the input shaft 82a, and positioned radially outward of the input shaft 82a. Furthermore, the carrier 38 is positioned in the same position as the magnet 31 in the axial direction, and positioned radially outward of the magnet 31.

The stator 34 is attached to the carrier 38 arranged in this manner. In detail, the first stator 34a and the second stator 34b are attached to the carrier 54 with the teeth 36 located on the radial inside of the carrier 54 and the flange 35 protruding from the radial inside to the radial outside of the carrier 54. As a result, the pair of stators 34, the first stator 34a and the second stator 34b, are both arranged in the same position as the magnet 31 in the axial direction, and are arranged radially outward of the magnet 31.

The first stator 34a and the second stator 34b are attached to a carrier 38 that is integrally formed with a second sleeve 37 that is attached to the output shaft 82b, and are therefore rotatable together with the output shaft 82b. In other words, the stator 34 that is arranged to be rotatable together with the output shaft 82b has a flange portion 35 that protrudes radially outward from the output shaft 82b, and is fixed to the output shaft 82b.

As described above, the magnet 31 is fixed to the input shaft 82a and the stator 34 is fixed to the output shaft 82b, so that the magnet 31 and the stator 34 are arranged inside the housing 20 together with the input shaft 82a and the output shaft 82b. be done. In the first embodiment, the magnet 31 and the stator 34 are arranged inside the first housing 21.

The pair of magnetic flux collecting yokes 41 are disposed on the sensor housing 40, which is attached to the first housing 21. As a result, the magnetic flux collecting yoke 41 is fixed to the first housing 21 via the sensor housing 40. In addition, the Hall IC 43 (see FIG. 3) is mounted on the circuit board 44, which is disposed on the sensor housing 40 at a position where the Hall IC 43 is disposed between the pair of magnetic flux collecting yokes 41. Therefore, the Hall IC 43 mounted on the circuit board 44 is also fixed to the first housing 21 via the sensor housing 40.

The bearings 60 and 68, which rotatably support the output shaft 82b, are so-called rolling bearings. Of the bearings 60 and 68, the bearing 68 rotatably supports the output shaft 82b relative to the second housing 25. That is, the bearing 68 is disposed between the output shaft 82b and the second housing 25 by fitting its inner circumferential surface to the output shaft 82b and its outer circumferential surface to the second housing 25, and supports the output shaft 82b rotatably relative to the second housing 25. A protruding portion 27 that protrudes radially inward is formed on the inner circumferential surface 26 of the second housing 25 into which the bearing 68 is fitted, and the bearing 68 abuts against the protruding portion 27 in the axial direction. As a result, the bearing 68 is fitted into the second housing 25 in a state in which the protruding portion 27 restricts the bearing 68 from moving axially relative to the second housing 25.

On the other hand, the bearing 60 supports the output shaft 82b rotatably relative to the first housing 21. That is, the bearing 60 is disposed between the output shaft 82b and the first housing 21 by fitting its inner circumferential surface to the output shaft 82b and its outer circumferential surface to the first housing 21, and supports the output shaft 82b rotatably relative to the first housing 21. At this time, a retainer 50 is disposed between the bearing 60 and the first housing 21, and the retainer 50 is attached to the bearing 60 such that its axial movement relative to the bearing 60 is restricted. The bearing 60 fits into the first housing 21 via the retainer 50.

FIG. 5 is a detailed schematic diagram of the retainer 50 and bearing 60 shown in FIG. 4. The bearing 60, which is a rolling bearing, includes an outer ring 61, an inner ring 62, and a plurality of rolling elements 63 that are disposed between the outer ring 61 and the inner ring 62 and are held by the outer ring 61 and the inner ring 62. The outer diameter of the bearing 60 is equal to or less than the outer diameter of the stator 34 (see FIGS. 3 and 4) fixed to the output shaft 82b. That is, in the bearing 60, the outer diameter of the outer ring 61 is smaller than the outer diameter of the flange portion 35 (see FIGS. 3 and 4) of the stator 34.

The retainer 50 has a cylindrical portion 51 formed in a substantially cylindrical shape, an inner extension portion 56, and an outer extension portion 55. The cylindrical portion 51 has an inner diameter approximately equal to the outer diameter of the outer ring 61 of the bearing 60, and an outer diameter approximately equal to the inner diameter of the first housing 21 at the position where the retainer 50 is disposed. It's getting dark. Further, the outer diameter of the cylindrical portion 51 is larger than the outer diameter of the stator 34 (see FIGS. 3 and 4). That is, the outer diameter of the cylindrical portion 51 of the retainer 50 is larger than the outer diameter of the flange portion 35 (see FIGS. 3 and 4) of the stator 34.

The inner extension part 56 is disposed at the end 51b of the cylindrical part 51 in the axial direction, and has an annular shape extending inward in the radial direction of the cylindrical part 51 from the end 51b of the cylindrical part 51. In other words, the inner extension part 56 is formed in a disc shape with a hole in the center in the radial direction, the outer diameter of the disc is the same as the diameter of the cylindrical part 51, and the outer peripheral part of the disc is cylindrical. The end portion 51b of the portion 51 is connected to the end portion 51b. Further, the inner diameter of the inner extension portion 56 is smaller than the outer diameter of the outer ring 61 of the bearing 60 and larger than the outer diameter of the inner ring 62 of the bearing 60.

The outer extension 55 is disposed at the end 51a opposite the end where the inner extension 56 is disposed in the axial direction of the cylindrical portion 51, and is formed in an annular shape extending from the end 51a of the cylindrical portion 51 to the outside in the radial direction of the cylindrical portion 51. In other words, the outer extension 55 is formed in a disk shape with a hole in the center in the radial direction, the inner diameter of the disk is the same as the diameter of the cylindrical portion 51, and the inner peripheral portion of the disk is connected to the end 51a of the cylindrical portion 51.

The retainer 50 is disposed in the first housing 21 with the axial direction of the cylindrical portion 51 aligned along the central axis AX (see FIG. 2) of the steering shaft 82. The first housing 21 has a retainer abutment portion 23, which is a part of the first housing 21 within the range in which the retainer 50 is disposed in the axial direction and faces in the axial direction and abuts against the retainer 50. The retainer abutment portion 23 is a surface that faces in the axial direction toward the position of the second housing 25 (see FIG. 2), and is formed to include a portion whose radial size is at least as large as the radial size of the outer extension portion 55 of the retainer 50.

The retainer 50 is arranged in the first housing 21 with the outer extension 55 located on the side where the second housing 25 is located in the axial direction, and the inner extension 56 located on the opposite side to the side where the second housing 25 is located in the axial direction. The retainer 50 arranged in the first housing 21 has the outer peripheral surface 52 of the cylindrical portion 51 radially opposed to the inner peripheral surface 22 of the first housing 21. That is, the outer peripheral surface 52 of the cylindrical portion 51 of the retainer 50 fits into the inner peripheral surface 22 of the first housing 21. In addition, the surface of the outer extension 55 of the retainer 50 on the side where the cylindrical portion 51 is located in the axial direction of the cylindrical portion 51 abuts against the retainer abutment portion 23 of the first housing 21. In other words, the first housing 21 abuts against the surface of the outer extension 55 on the side where the cylindrical portion 51 is located, which is the surface of the cylindrical portion 51 of the retainer 50 facing the axial direction. As a result, the retainer 50 is restricted from moving relative to the first housing 21 in the axial direction opposite the side where the second housing 25 is located by the retainer abutment portion 23 and the outer extension portion 55.

The retainer 50 also faces the bearing 60 in the radial direction. That is, in the retainer 50, the inner circumferential surface 53 of the cylindrical portion 51 faces the outer circumferential surface 64 of the outer ring 61 of the bearing 60 in the radial direction; It fits into the outer peripheral surface 64 of the outer ring 61. Further, in the retainer 50, the surface of the inner extension portion 56 on the side where the cylindrical portion 51 is located in the axial direction of the cylindrical portion 51 contacts the end surface 65 of the bearing 60 in the axial direction. That is, in the retainer 50, the inner extension portion 56 abuts on the end surface 65 of the outer ring 61 of the bearing 60 on the side opposite to the side where the second housing 25 is located in the axial direction. As a result, relative movement of the retainer 50 with respect to the bearing 60 in the axial direction in the direction in which the second housing 25 is located is restricted by the end surface 65 of the bearing 60 and the inner extension part 56, and the cylindrical part 51 of the retainer 50 is The bearing is attached to the bearing 60 with movement of the bearing in the axial direction relative to the outer ring 61 being restricted.

The retainer 50 is thus interposed between the first housing 21 and the bearing 60 that rotatably supports the output shaft 82b with respect to the first housing 21. It is arranged inside the inner circumferential surface 22 of the housing 21 . The retainer 50 disposed between the first housing 21 and the bearing 60 is capable of applying preload to the bearing 60. The retainer 50 that applies a preload to the bearing 60 is made of a material such as a spring so that the pressure received from the first housing 21 can be appropriately applied to the bearing 60 using an elastic body. Steel is used.

FIG. 6 is an explanatory diagram of how force is transmitted when applying preload from the retainer 50 to the bearing 60. In the first housing 21, the retainer contact portion 23 contacts the outer extension portion 55 of the retainer 50, thereby making it possible to apply preload in the axial direction of the bearing 60 from the retainer 50 to the outer ring 61 of the bearing 60. ing.

In other words, the inner ring 62 of the bearing 60 is fitted to the output shaft 82b, and the inner ring 62 is in contact with the core metal portion 94a of the worm wheel 94, so that the inner ring 62 of the bearing 60 is restricted from moving axially toward the second housing 25. Also, the inner extension portion 56 of the retainer 50 is in contact with the end face 65 of the outer ring 61 of the bearing 60 on the side opposite to the side where the second housing 25 is located in the axial direction.

On the other hand, in the first housing 21 in which the retainer abutting part 23 abuts the outer extension part 55 of the retainer 50, the positional relationship of the retainer abutting part 23 with respect to the output shaft 82b is such that the first housing 21 is connected to the second housing 25. In this state, the retainer contact portion 23 is formed in a positional relationship that allows a pressing force F to be applied to the outer extension portion 55. In this case, the pressing force F applied from the retainer abutting portion 23 to the outer extension portion 55 is a force that directs the outer extension portion 55 toward the side where the second housing 25 is located in the axial direction.

The pressing force F applied from the retainer abutment portion 23 of the first housing 21 to the outer extension portion 55 of the retainer 50 acts on the entire retainer 50. Therefore, the pressing force F applied from the retainer abutment portion 23 to the outer extension portion 55 of the retainer 50 acts from the inner extension portion 56 of the retainer 50 to the outer ring 61 of the bearing 60, whose end face 65 the inner extension portion 56 is in contact with. As a result, a pressing force F acts on the outer ring 61 of the bearing 60 from the inner extension portion 56 of the retainer 50 in a direction that moves the outer ring 61 toward the side where the second housing 25 is located in the axial direction.

The outer ring 61, to which the pressing force F from the inner extension 56 of the retainer 50 acts, moves in the axial direction in which the pressing force F acts, and comes into contact with the rolling elements 63 that are held by the outer ring 61 and the inner ring 62 and positioned inside the outer ring 61 in the radial direction. As a result, the pressing force F acts on the rolling elements 63 from the outer ring 61 in a direction that moves the rolling elements 63 axially toward the side where the second housing 25 is located, and the outer ring 61 is in a state where it applies a preload to the rolling elements 63.

The rolling elements 63 on which the pressing force F is applied from the outer ring 61 move in the direction in which the pressing force F acts in the axial direction due to the pressing force F, and come into contact with the inner ring 62 located inside the rolling elements 63 in the radial direction. As a result, a pressing force F is applied from the rolling elements 63 to the inner ring 62 in the axial direction toward the side where the second housing 25 is located, and the rolling elements 63 are in a state of applying preload to the inner ring 62.

That is, the pressing force F acting from the retainer abutment portion 23 of the first housing 21 to the outer extension portion 55 of the retainer 50 and from the outer extension portion 55 to the outer ring 61 of the bearing 60 acts as a preload that brings the outer ring 61 into contact with the rolling element 63 and the rolling element 63 into contact with the inner ring 62. That is, the pressing force F applied from the first housing 21 to the retainer 50 acts on the bearing 60 from the outer ring 61 to the rolling element 63 toward the side where the second housing 25 is located in the axial direction and toward the inside in the radial direction, and acts as a preload that brings the rolling element 63 into contact with the inner ring 62. As a result, the bearing 60 maintains a state in which the outer ring 61 and the rolling element 63, and the rolling element 63 and the inner ring 62 are in contact with each other, and a state in which there is no gap between the outer ring 61 or the inner ring 62 and the rolling element 63 and the rattle is eliminated.

The bearing 68 (see FIG. 4) arranged between the output shaft 82b and the second housing 25 is preloaded by the second housing 25. More specifically, the bearing 68 is a rolling bearing having an outer ring 68a, an inner ring 68b, and a rolling body 68c, similar to the bearing 60. The protruding portion 27 (see FIG. 4) of the second housing 25 abuts against the outer ring 68a of the bearing 68 formed in this way from the side opposite to the side where the worm wheel 94 is located in the axial direction. The core metal portion 94a (see FIG. 4) of the worm wheel 94 abuts against the inner ring 68b of the bearing 68 from the side opposite to the side where the protruding portion 27 of the second housing 25 is located in the axial direction. Therefore, the protruding portion 27 of the second housing 25 and the core metal portion 94a of the worm wheel 94 act on the outer ring 68a and the inner ring 68b of the bearing 68 in the axial direction in opposite directions.

That is, a pressing force acts on the outer ring 68a of the bearing 68 from the protruding portion 27 of the second housing 25 toward the side where the worm wheel 94 is located in the axial direction, and the inner ring 68b of the bearing 68 is restricted in its axial movement by the core metal portion 94a of the worm wheel 94 abutting against it from the side opposite to the side where the protruding portion 27 of the second housing 25 is located in the axial direction. For the bearing 68, whose axial movement of the inner ring 68b is restricted by the core metal portion 94a of the worm wheel 94, the pressing force acting on the side where the worm wheel 94 is located in the axial direction from the protruding portion 27 of the second housing 25 acts as a preload on the bearing 68. That is, the pressing force acting on the bearing 68 in the axial direction acts on the bearing 68 as a preload acting between the outer ring 68a and the rolling element 68c, and between the rolling element 68c and the inner ring 68b. As a result, the bearing 68 maintains a state in which the outer ring 68a and the rolling body 68c, and the rolling body 68c and the inner ring 68b are in contact, eliminating any gaps between the outer ring 61 and the inner ring 68b and the rolling body 68c, and maintaining a state in which rattle is eliminated.

Next, the operation of the steering device 80 will be explained. When the steering wheel 81 is operated while driving the vehicle in which the steering device 80 is mounted, the steering force applied to the steering wheel 81 is transmitted from the steering wheel 81 to the steering shaft 82. The steering force transmitted to the steering shaft 82 is transmitted as a steering torque from the steering shaft 82 to the intermediate shaft 85, and from the intermediate shaft 85 via the pinion shaft 87 to the pinion gear 88a. As a result, the steering gear 88 having the pinion gear 88a converts the rotational motion transmitted from the pinion gear 88a into a linear motion of the rack bar 88b, and operates the tie rod 89.

Further, the steering device 80 according to the first embodiment includes an electric motor 91 that generates an auxiliary steering torque to assist the driver's steering. The electric motor 91 generates auxiliary steering torque based on the steering torque detected by the torque detection section 30 disposed between the input shaft 82a and the output shaft 82b of the steering shaft 82.

The torque detection unit 30 detects the steering torque applied from the steering wheel 81 to the steering shaft 82 based on the angle of relative rotation when the input shaft 82a and the output shaft 82b rotate relative to each other. That is, since the input shaft 82a and the output shaft 82b are connected via the torsion bar 82c, when a steering torque is applied to the input shaft 82a of the steering shaft 82, the steering torque is transmitted between the input shaft 82a and the output shaft 82b via the torsion bar 82c. At that time, the torsion bar 82c is slightly twisted, causing the input shaft 82a and the output shaft 82b to rotate relative to each other.

The torque detection section 30 has the magnet 31 attached to the input shaft 82a and the stator 34 attached to the output shaft 82b, so that when the input shaft 82a and the output shaft 82b rotate relative to each other, the torque detection section 30 detects The magnet 31 and stator 34 also rotate relative to each other. The relative rotation angle between the magnet 31 and the stator 34 increases as the steering torque acting between the input shaft 82a and the output shaft 82b increases.

When the magnet 31 and the stator 34 rotate relative to each other, the magnetic flux acting on the stator 34 from the magnet 31 changes. The magnetic flux collection yoke 41 disposed near the stator 34 is capable of detecting changes in the magnetic flux acting on the stator 34 from the magnet 31. Therefore, when the magnet 31 and the stator 34 rotate relative to each other due to the relative rotation between the input shaft 82a and the output shaft 82b, the magnetic flux collecting yoke 41 disposed near the stator 34 moves from the magnet 31 to the stator 34. It is possible to detect changes in the magnetic flux acting on the magnetic flux.

In this way, the magnetic flux acting on the stator 34 from the magnet 31, detected by the magnetic flux collecting yoke 41, changes according to the angle of relative rotation between the magnet 31 and the stator 34. The Hall IC 43 detects the magnetic flux, which changes according to the angle of relative rotation between the magnet 31 and the stator 34 detected by the magnetic flux collecting yoke 41, with a Hall element, converts it into an electrical signal in an output circuit, and transmits it to the ECU 90 as an output signal from the torque detection unit 30. In other words, the torque detection unit 30 detects the change in the magnetic flux acting on the stator 34 from the magnet 31 with the magnetic flux collecting yoke 41 and the Hall IC 43, thereby detecting the steering torque applied to the input shaft 82a, and transmits the detected steering torque to the ECU 90 as an electrical signal.

The ECU 90 operates the electric motor 91 based on the electric signal transmitted from the torque detection section 30, and causes the electric motor 91 to generate an auxiliary steering torque. That is, the electric signal transmitted from the Hall IC 43 of the torque detection unit 30 to the ECU 90 changes depending on the angle of relative rotation between the magnet 31 and the stator 34, and the electric signal is applied to the steering wheel acting between the input shaft 82a and the output shaft 82b. Varies based on torque. Therefore, the ECU 90 uses the electrical signal transmitted from the Hall IC 43 of the torque detection section 30 as information that changes depending on the steering torque acting on the input shaft 82a and the output shaft 82b, and uses the electrical signal transmitted from the Hall IC 43 as information that changes depending on the steering torque acting on the input shaft 82a and the output shaft 82b. Based on this, the electric power value supplied to the electric motor 91 is adjusted, and the electric motor 91 generates an auxiliary steering torque.

That is, the ECU 90 obtains a steering torque signal from the torque detection section 30, a vehicle speed signal from the vehicle speed sensor 95, and further receives operation information of the electric motor 91 from a rotation detection device provided in the electric motor 91. The electric motor 91 generates an auxiliary steering torque based on the operation information, the steering torque, and the vehicle speed signal. The auxiliary steering torque generated by the electric motor 91 is transmitted to the output shaft 82b of the steering shaft 82 via the worm 93 and the worm wheel 94. Thereby, the steering force applied by the driver to the steering wheel 81 is assisted by the auxiliary steering torque generated by the electric motor 91.

Further, when the driver steers the steering wheel 81, the output shaft 82b of the steering shaft 82 rotates while being supported by the bearing 60. At that time, the bearing 60 is caused to move between the outer ring 61 and the rolling elements 63 and between the rolling elements 63 and the inner ring due to the pressing force F applied to the bearing 60 from the first housing 21 via the retainer 50. 62, a preload is applied.

Therefore, the bearing 60 maintains a state in which the outer ring 61 and the rolling element 63, and the rolling element 63 and the inner ring 62 are in contact with each other, so that even if vibrations caused by the vehicle traveling are transmitted to the bearing 60, the outer ring 61 and the rolling element 63, or the rolling element 63 and the inner ring 62 will not collide with each other. As a result, even if vibrations are transmitted to the bearing 60, the bearing 60 can rotatably support the steering shaft 82 without generating operating noises that would occur if the outer ring 61 or the inner ring 62 collided with the rolling element 63.

In addition, since the torque sensor device 10 according to the first embodiment applies a preload to the bearing 60 by interposing the retainer 50 between the first housing 21 and the bearing 60, the torque sensor device 10 has a structure that applies a preload to the bearing 60. When provided in the device 10, the torque sensor device 10 can be appropriately assembled.

Figure 7 is a schematic diagram of a torque sensor device 200 in which a preload applying member 210 is provided on the first housing 21. A structure in which a preload is applied to the bearing 60 by applying an axial pressing force to the bearing 60 can be realized, for example, by providing a preload applying member 210 on the first housing 21 as shown in Figure 7. In the torque sensor device 200 shown in Figure 7, the first housing 21 is formed with a preload applying member 210 that protrudes radially inward from the inner peripheral surface 22. The preload applying member 210 abuts against an end face 65 in the axial direction of the outer ring 61 of the bearing 60, thereby applying an axial pressing force to the outer ring 61 and applying a preload to the bearing 60.

However, the stator 34 of the torque detection unit 30 is fixed to the steering shaft 82, which is rotatably supported by the bearing 60. Therefore, if the preload applying member 210 is disposed on the inner peripheral surface 22 of the first housing 21, it becomes impossible to assemble the first housing 21.

In other words, when the bearing 60 is made smaller to prevent an increase in the weight of the torque sensor device 200, the outer diameter of the bearing 60 becomes smaller than the outer diameter of the stator 34 fixed to the steering shaft 82, i.e., the outer diameter of the first flange portion 35a and the second flange portion 35b of the stator 34. In this case, the preload applying member 210 that abuts against the end face 65 of the bearing 60 also becomes smaller according to the outer diameter of the bearing 60. As a result, the inner diameter of the preload applying member 210 becomes smaller than the outer diameter of the stator 34.

FIG. 8 is a schematic diagram showing a state in which the first housing 21 of the torque sensor device 200 shown in FIG. 7 is assembled. When assembling the first housing 21 to the steering shaft 82, the preload applying member 210 disposed on the first housing 21 is brought into contact with the bearing 60 fitted to the steering shaft 82 in the axial direction. Assemble from the direction. That is, the first housing 21 is assembled to the steering shaft 82 from the direction in which the stator 34 is disposed when viewed from the bearing 60.

However, since the preload applying member 210 disposed in the first housing 21 has an inner diameter smaller than the outer diameter of the stator 34, the first housing 21 is assembled to the steering shaft 82 from the direction in which the stator 34 is disposed. In this case, the preload applying member 210 will interfere with the stator 34. Therefore, when the preload applying member 210 is formed in the first housing 21, when the first housing 21 is assembled to the steering shaft 82, the preload applying member 210 interferes with the stator 34, so that the first housing 21 It becomes impossible to assemble it to the steering shaft 82.

In contrast, in the torque sensor device 10 according to the first embodiment, the retainer 50 is used to apply preload to the bearing 60, so that the first housing 21 can be assembled to the steering shaft 82 while ensuring a structure for applying preload to the bearing 60. FIG. 9 is a schematic diagram of the torque sensor device 10 according to the first embodiment before the first housing 21 is assembled to the steering shaft 82. In the torque sensor device 10 according to the first embodiment, the retainer 50 is assembled to the bearing 60 before the first housing 21 is assembled to the steering shaft 82. The retainer 50 is arranged such that the outer ring 61 of the bearing 60 is fitted into the cylindrical portion 51 of the retainer 50, and the inner extension portion 56 of the retainer 50 is in contact with the end face 65 of the outer ring 61 on the axial side where the stator 34 is located.

The bearing 60 to which the retainer 50 is attached can be fitted to the steering shaft 82 by fitting the bearing 60 to which the retainer 50 is attached from the side opposite to the side where the stator 34 is located with respect to the steering shaft 82. Alternatively, the bearing 60 may be fitted to the steering shaft 82 before the stator 34 is attached to the steering shaft 82, and the stator 34 may be fixed to the steering shaft 82 after the retainer 50 is assembled to the bearing 60 fitted to the steering shaft 82.

The first housing 21 is assembled to the steering shaft 82 to which the bearing 60 with the retainer 50 assembled thereto is fitted and to which the stator 34 is fixed. FIG. 10 is a schematic diagram showing the state in which the first housing 21 is assembled to the steering shaft 82 shown in FIG. 9. The first housing 21 is assembled to the steering shaft 82 from a direction in which the retainer abutment portion 23 of the first housing 21 abuts in the axial direction against the outer extension portion 55 of the retainer 50 assembled to the bearing 60. In other words, the first housing 21 is assembled to the steering shaft 82 from the direction in which the stator 34 is arranged as viewed from the bearing 60.

In the torque sensor device 10 according to the first embodiment, the inner circumferential surface 22 of the first housing 21 does not have a portion smaller in diameter than the outer diameter of the stator 34; The retainer contact portion 23 can be brought into contact with the outer extension portion 55 of the retainer 50 without interfering with the retainer contact portion 23. Thereby, the retainer 50 can apply a preload to the bearing 60 by the pressing force applied from the first housing 21, and the torque sensor device 10 can secure a structure that applies a preload to the bearing 60 while also ensuring that the steering shaft The first housing 21 can be assembled to 82.

As described above, in the torque sensor device 10 and the steering device 80 according to the first embodiment, the retainer 50 interposed between the first housing 21 and the bearing 60 has the cylindrical portion 51. is attached to the bearing 60 with movement of the bearing 60 in the axial direction relative to the outer ring 61 being restricted. Further, the first housing 21 abuts against a surface of the cylindrical portion 51 of the retainer 50 facing in the axial direction. Thereby, the retainer 50 can apply the pressing force F applied to the retainer 50 from the first housing 21 to the bearing 60, and can apply preload to the bearing 60. Therefore, even if vibrations are transmitted to the bearing 60 when the vehicle is running, collisions between the outer ring 61 and the rolling elements 63 of the bearing 60 and collisions between the inner ring 62 and the rolling elements 63 can be suppressed, and any damage caused by these collisions can be suppressed. The operating noise can be suppressed.

In addition, when applying preload to the bearing to suppress operating noise, a preload can be applied to the bearing 60 by interposing a retainer 50 between the first housing 21 and the bearing 60. This makes it possible to select a bearing with an outer diameter smaller than the inner circumferential surface 22 of the first housing 21, and the retainer 50 can apply preload to the bearing 60 without increasing the weight of the bearing. As a result, it is possible to apply preload to the bearing 60 and suppress operating noise while minimizing the increase in weight.

The retainer 50 has a cylindrical portion 51, an outer extension portion 55, and an inner extension portion 56, and the outer extension portion 55 abuts against the retainer abutment portion 23 of the first housing 21, and the inner extension portion 56 abuts against the end face 65 of the outer ring 61 in the axial direction of the bearing 60. As a result, the first housing 21 abuts against the surface facing the axial direction of the cylindrical portion 51 of the retainer 50, and the retainer 50 is attached to the bearing 60 while restricting the axial movement of the bearing 60 relative to the outer ring 61, so that the pressing force F applied from the first housing 21 to the outer extension portion 55 can be applied to the bearing 60 from the inner extension portion 56, and a preload can be applied to the bearing 60. Therefore, even if vibrations during vehicle running are transmitted to the bearing 60, the collision between the outer ring 61 and the rolling element 63 of the bearing 60 and the collision between the inner ring 62 and the rolling element 63 can be suppressed, and the operating noise caused by these collisions can be suppressed. As a result, it is possible to apply preload to the bearing 60 and suppress operating noise while minimizing weight increase.

In addition, because the outer diameter of the bearing 60 is equal to or smaller than the outer diameter of the stator 34, the bearing 60 can be made smaller and its weight can be reduced. As a result, it is possible to apply a preload to the bearing 60 and suppress operating noise while preventing an increase in weight.

Further, since the outer diameter of the cylindrical portion 51 of the retainer 50 is larger than the outer diameter of the stator 34, the inner diameter of the first housing 21 that makes the retainer 50 face the inner circumferential surface 22 in the radial direction is the outer diameter of the stator 34. can be made larger than. Thereby, the first housing 21 can be assembled to the steering shaft 82 without causing the first housing 21 to interfere with the stator 34. As a result, while making it possible to assemble the first housing 21 to the steering shaft 82, the retainer 50 exerts a preload on the bearing 60 due to the pressing force applied to the retainer 50 from the retainer contact portion 23 of the first housing 21. can be given.

In addition, since the inner diameter of the inner extension 56 of the retainer 50 is smaller than the outer diameter of the outer ring 61 of the bearing 60 and larger than the outer diameter of the inner ring 62, the inner extension 56 can apply an axial pressing force to the outer ring 61 without the inner extension 56 impeding the relative rotation between the outer ring 61 and the inner ring 62. This allows the retainer 50 to apply a preload to the bearing 60 while suppressing an increase in resistance when the outer ring 61 and the inner ring 62 of the bearing 60 rotate relative to each other. As a result, it is possible to apply a preload to the bearing 60 and suppress operating noise while suppressing an increase in resistance when the output shaft 82b rotates relative to the first housing 21.

In addition, the first housing 21 provides a preload in the axial direction of the bearing 60 from the retainer 50 to the outer ring 61 of the bearing 60 when the retainer contact portion 23 contacts the outer extension portion 55 of the retainer 50. With this configuration, preload can be applied to the bearing 60. Therefore, manufacturing costs when providing a structure that applies preload to the bearing 60 can be reduced. As a result, it is possible to apply preload to the bearing 60 and suppress operating noise while suppressing an increase in manufacturing costs.

[Second embodiment]
Next, a torque sensor device 10 according to a second embodiment will be described. The same components as those in the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted. The following description will focus on the differences from the first embodiment.

Figure 11 is a cross-sectional view of a main part of the torque sensor device 10 according to the second embodiment. In the torque sensor device 10 according to the second embodiment, as in the first embodiment, a retainer 150 is disposed between the bearing 60 that rotatably supports the output shaft 82b and the first housing 21, and the bearing 60 is disposed inside the first housing 21 via the retainer 150. Also, in the torque sensor device 10 according to the second embodiment, unlike the first embodiment, a step portion 24 is formed on the inner circumferential surface 22 of the first housing 21, and the retainer 150 is disposed in the step portion 24 of the first housing 21.

Figure 12 is a detailed schematic diagram of the retainer 150 and bearing 60 shown in Figure 11. In the torque sensor device 10 according to the second embodiment, the retainer 150 also has an inner extension 156 that extends from the end 151b in the axial direction of the cylindrical portion 151 to the inside in the radial direction of the cylindrical portion 151. On the other hand, in the second embodiment, unlike the first embodiment, the retainer 150 does not have an outer extension 55 (see Figure 5).

The retainer 150 having the inner extension part 156 is attached to the bearing 60 so that the surface of the inner extension part 156 on the side where the cylindrical part 151 is located in the axial direction of the cylindrical part 151 comes into contact with the end face 65 of the outer ring 61 in the axial direction. It will be done. As a result, relative movement of the cylindrical portion 151 of the retainer 150 to the side opposite to the side where the inner extension portion 156 is located in the axial direction with respect to the outer ring 61 of the bearing 60 is restricted, and the axial direction of the bearing 60 with respect to the outer ring 61 is restricted. It is attached to the bearing 60 with its movement regulated. Further, the cylindrical portion 151 of the retainer 150 is press-fitted into the outer ring 61 of the bearing 60. The retainer 150 is attached to the bearing 60 with the cylindrical portion 151 press-fitted into the outer ring 61 of the bearing 60 such that movement of the bearing 60 in the axial direction with respect to the outer ring 61 is restricted.

The step portion 24 of the first housing 21, which is the portion of the first housing 21 where the retainer 150 is disposed, has a large diameter portion 24a, a small diameter portion 24b, and a connection portion 24c. The large diameter portion 24a is formed so that the inner diameter of the inner circumferential surface is slightly larger than the outer diameter of the cylindrical portion 151 of the retainer 150, and when the first housing 21 holds the retainer 150, the inner circumferential surface faces the outer circumferential surface 152 of the cylindrical portion 151 of the retainer 150. The width of the large diameter portion 24a in the axial direction is approximately the same as the width of the cylindrical portion 151 in the axial direction.

The small diameter portion 24b is located on the opposite side of the large diameter portion 24a from the side where the worm wheel 94 is located in the axial direction, and has an inner diameter smaller than the inner diameter of the large diameter portion 24a. Specifically, the inner diameter of the small diameter portion 24b of the step portion 24 is larger than the outer diameter of the stator 34 of the torque detection unit 30 (see FIG. 12) and the inner diameter of the inner extension portion 156 of the retainer 150, and is smaller than the outer diameter of the cylindrical portion 151 of the retainer 150.

The connecting portion 24c has an annular surface facing toward the side where the worm wheel 94 is located in the axial direction, and is formed to extend in the radial direction, thereby connecting the large diameter portion 24a and the small diameter portion of the stepped portion 24. 24b. Furthermore, when the retainer 150 is held by the first housing 21, the connecting portion 24c is formed to face the end portion 151b of the retainer 150 in the axial direction on the side where the inner extension portion 156 is located.

When holding the retainer 150 with the first housing 21, the connecting portion 24c of the stepped portion 24 comes into contact with the end portion 151b of the retainer 150 on the side where the inner extension portion 156 is located, so that the first housing 21 holds the retainer The cylindrical portion 150 contacts the axially facing surface of the cylindrical portion 151 . As described above, by interposing the retainer 150 between the first housing 21 and the bearing 60, the retainer 150 can apply preload to the bearing 60 also in the second embodiment.

Figure 13 is an explanatory diagram of how force is transmitted when preloading the bearing 60 from the retainer 150. The first housing 21 is capable of applying axial preload to the outer ring 61 of the bearing 60 from the retainer 150 by abutting the connection portion 24c of the stepped portion 24 against the end portion 151b on the side where the inner extension portion 156 in the axial direction of the cylindrical portion 151 of the retainer 150 is located.

That is, in the bearing 60, the inner ring 62 is fitted to the output shaft 82b as in the first embodiment, and furthermore, the inner ring 62 is in contact with the core metal part 94a of the worm wheel 94, so the inner ring of the bearing 60 62 is restricted from moving toward the second housing 25 in the axial direction. Further, the inner extension portion 156 of the retainer 150 is in contact with an end surface 65 of the outer ring 61 of the bearing 60 on the side opposite to the side where the second housing 25 is located in the axial direction.

On the other hand, in the first housing 21, in which the connecting portion 24c of the stepped portion 24 contacts the end 151b of the retainer 150 on the side where the inner extension portion 156 is located, the positional relationship of the connecting portion 24c with respect to the output shaft 82b is 21 is formed in a positional relationship that allows a pressing force F to be applied from the connecting portion 24c to the end portion 151b of the retainer 150 when the retainer 21 is connected to the second housing 25. In this case, the pressing force F applied from the connecting portion 24c to the end portion 151b of the retainer 150 is a force that moves the retainer 150 toward the side where the second housing 25 is located in the axial direction.

The pressing force F applied from the connecting portion 24c of the first housing 21 to the end portion 151b of the retainer 150 acts on the entire retainer 150. Therefore, the pressing force F applied to the retainer 150 from the connecting part 24c acts from the inner extension part 156 of the retainer 150 to the outer ring 61 of the bearing 60, where the inner extension part 156 is in contact with the end surface 65. . As a result, a pressing force F acts on the outer ring 61 of the bearing 60 from the inner extension portion 156 of the retainer 150 in a direction that directs the outer ring 61 toward the side where the second housing 25 is located in the axial direction.

The outer ring 61 of the bearing 60, to which a pressing force F from the inner extension 156 of the retainer 150 acts, moves in the direction in which the pressing force F acts, and comes into contact with the rolling element 63. As a result, the pressing force F acts on the rolling element 63 from the outer ring 61 in the axial direction in which the second housing 25 is located, and the outer ring 61 is in a state in which it applies a preload to the rolling element 63. The rolling element 63, to which the pressing force F from the outer ring 61 acts, moves in the direction in which the pressing force F acts, and comes into contact with the inner ring 62. As a result, the pressing force F acts on the inner ring 62 from the rolling element 63 in the axial direction in which the second housing 25 is located, and the rolling element 63 is in a state in which it applies a preload to the inner ring 62.

That is, the pressing force F acting on the retainer 150 from the connection portion 24c of the first housing 21 and on the outer ring 61 of the bearing 60 from the retainer 150 acts as a preload that brings the outer ring 61 into contact with the rolling element 63 and the rolling element 63 into contact with the inner ring 62. In this way, the first housing 21 can apply a preload in the axial direction of the bearing 60 to the outer ring 61 of the bearing 60 from the retainer 150 by abutting the connection portion 24c against the end portion 151b on the side where the inner extension portion 156 of the retainer 150 is located. As a result, in the second embodiment, the bearing 60 maintains a state in which the outer ring 61 and the rolling element 63, and the rolling element 63 and the inner ring 62 are in contact with each other, and a state in which there is no gap between the outer ring 61 or the inner ring 62 and the rolling element 63 and the rattle is eliminated.

The torque sensor device 10 according to the second embodiment configured as above can assemble the first housing 21 to the steering shaft 82 while ensuring a structure for applying a preload to the bearing 60 by applying a preload to the bearing 60 using the retainer 150, as in the first embodiment. FIG. 14 is a schematic diagram of the torque sensor device 10 according to the second embodiment before the first housing 21 is assembled to the steering shaft 82. In the torque sensor device 10 according to the second embodiment, the retainer 150 is assembled to the bearing 60 before the first housing 21 is assembled to the steering shaft 82. The retainer 150 is arranged such that the outer ring 61 of the bearing 60 is fitted into the cylindrical portion 151 of the retainer 150, and the inner extension portion 156 of the retainer 150 is abutted against the end face 65 of the outer ring 61 on the axial side where the stator 34 is located.

The retainer 150 is assembled to the bearing 60 in such a direction that the side on which the inner extension portion 156 is located in the axial direction is located on the side on which the stator 34 is located when the bearing 60 is fitted to the steering shaft 82. In other words, the bearing 60 with the retainer 150 assembled is fitted onto the steering shaft 82 in such a direction that the side on which the inner extension portion 156 is located is located on the side on which the stator 34 is located in the axial direction.

The bearing 60 to which the retainer 150 is assembled is fitted to the steering shaft 82 from the side opposite to the side where the stator 34 is located. Thereby, the bearing 60 with the retainer 150 assembled can be fitted onto the steering shaft 82. Alternatively, before attaching the stator 34 to the steering shaft 82, the bearing 60 is fitted to the steering shaft 82, and after the retainer 150 is assembled to the bearing 60 fitted to the steering shaft 82, the stator 34 is fixed to the steering shaft 82. You may.

The first housing 21 is fitted to the bearing 60 with the retainer 150 attached thereto, and is assembled to the steering shaft 82 to which the stator 34 is fixed. FIG. 15 is a schematic diagram showing the state in which the first housing 21 is assembled to the steering shaft 82 shown in FIG. 14. The first housing 21 is assembled to the steering shaft 82 from a direction that allows the connecting portion 24c of the stepped portion 24 to abut in the axial direction against the end portion 151b on the side where the inner extension portion 156 of the retainer 150 assembled to the bearing 60 is located. In other words, the first housing 21 is assembled to the steering shaft 82 from the direction in which the stator 34 is located as viewed from the bearing 60.

The first housing 21 has a step portion 24 with an inner diameter of the small diameter portion 24b that is larger than the outer diameter of the stator 34, so that the first housing 21 can abut the connection portion 24c against the end portion 151b of the retainer 150 on the side where the inner extension portion 156 is located, without interfering with the stator 34. This allows the retainer 150 to apply a preload to the bearing 60 by the pressing force applied by the first housing 21, and the torque sensor device 10 can assemble the first housing 21 to the steering shaft 82 while ensuring a structure that applies a preload to the bearing 60.

As described above, in the torque sensor device 10 according to the second embodiment, the retainer 150 has the inner extension part 156, and the inner extension part 156 comes into contact with the end surface 65 of the outer ring 61, so that the cylindrical part of the retainer 150 151 is attached to the bearing 60 so that its movement in the axial direction relative to the outer ring 61 is restricted. The first housing 21 also has a stepped portion 24 having a large diameter portion 24a, a small diameter portion 24b, and a connecting portion 24c, and the connecting portion is located at the end 151b of the retainer 150 on the side where the inner extension portion 156 is located. 24c comes into contact with the first housing 21, so that the first housing 21 comes into contact with the surface of the cylindrical portion 151 of the retainer 150 that faces in the axial direction. Thereby, the pressing force F applied from the first housing 21 to the end 151b of the retainer 150 on the side where the inner extension part 156 is located can be applied from the inner extension part 56 to the bearing 60, and the bearing 60 A preload can be applied to the Therefore, even if vibrations are transmitted to the bearing 60 when the vehicle is running, collisions between the outer ring 61 and the rolling elements 63 of the bearing 60 and collisions between the inner ring 62 and the rolling elements 63 can be suppressed, and the collisions caused by these collisions can be suppressed. The operating noise can be suppressed. As a result, it is possible to apply preload to the bearing 60 and suppress operating noise while suppressing an increase in weight.

In addition, the first housing 21 applies an axial preload from the retainer 150 to the outer ring 61 of the bearing 60 by abutting the connection portion 24c against the end portion 151b of the retainer 150 on the side where the inner extension portion 156 is located, so that even if the size of the bearing 60 is small relative to the first housing 21, a preload can be applied to the bearing 60. As a result, when the size of the bearing 60 is small relative to the first housing 21, a preload can be applied to the bearing 60 with the bearing 60 remaining small relative to the first housing 21 without using a large bearing 60 to match the first housing 21. Therefore, the manufacturing cost when providing a structure for applying a preload to the bearing 60 can be reduced. As a result, it is possible to apply a preload to the bearing 60 and suppress operating noise while suppressing an increase in manufacturing costs.

[Third embodiment]
Next, a torque sensor device 10 according to a third embodiment will be explained. Components that are the same as those in the second embodiment are given the same reference numerals and descriptions thereof will be omitted. Hereinafter, the differences from the second embodiment will be mainly explained.

Figure 16 is a cross-sectional view of a main part of the torque sensor device 10 according to the third embodiment. In the torque sensor device 10 according to the third embodiment, a retainer 250 is disposed between the first housing 21 and the bearing 60 that rotatably supports the output shaft 82b, as in the second embodiment, and the bearing 60 is disposed inside the first housing 21 via the retainer 250. Also, a step portion 24 is formed on the inner circumferential surface 22 of the first housing 21, as in the second embodiment, and the retainer 250 is disposed in the step portion 24 of the first housing 21.

Figure 17 is a detailed schematic diagram of the retainer 250 and bearing 60 shown in Figure 16. In the torque sensor device 10 according to the third embodiment, the retainer 250 also has a cylindrical portion 251 formed in a substantially cylindrical shape. On the other hand, unlike the second embodiment, the retainer 250 in the third embodiment does not have an inner extension portion 156 (see Figure 15). In other words, in the third embodiment, the retainer 250 is a member formed in a substantially cylindrical shape as a whole.

The retainer 250 is attached to the bearing 60 with its axial movement relative to the outer ring 61 restricted by the cylindrical portion 251 being pressed into the outer ring 61 of the bearing 60. In other words, in the third embodiment, the retainer 250 is attached to the bearing 60 with its axial movement relative to the outer ring 61 restricted by the retainer 250 formed in a substantially cylindrical shape being pressed into the outer ring 61 of the bearing 60 without using the inner extension portion 156 as in the second embodiment. In other words, in the third embodiment, the retainer 250 is restricted from axial movement relative to the outer ring 61 of the bearing 60 only by the fitting force caused by the retainer 250 formed in a substantially cylindrical shape being pressed into the outer ring 61 of the bearing 60. In this way, the retainer 250 pressed into the outer ring 61 of the bearing 60 is made of the same material as the bearing 60, for example, steel or stainless steel is used.

When the first housing 21 holds the retainer 250, the connecting part 24c of the stepped part 24 comes into contact with one end 251b of the retainer 250 in the axial direction, so that the first housing 21 can hold the cylindrical part of the retainer 250. 251 facing in the axial direction. That is, the connecting portion 24c of the stepped portion 24 contacts an end portion 251b of the retainer 250 on the side opposite to the side where the worm wheel 94 and the second housing 25 are located in the axial direction.

As described above, the retainer 250 is held by the first housing 21, the retainer 250 is interposed between the first housing 21 and the bearing 60, and the connecting portion 24c of the first housing 21 is brought into contact with the end portion 251b of the retainer 250. By bringing them into contact with each other, the retainer 250 can also apply preload to the bearing 60 in the third embodiment.

FIG. 18 is an explanatory diagram of how force is transmitted when applying preload from the retainer 250 to the bearing 60. In the first housing 21, the connecting portion 24c of the stepped portion 24 contacts one end 251b in the axial direction of the cylindrical portion 251 of the retainer 250, so that the bearing 60 is moved from the retainer 250 to the outer ring 61 of the bearing 60. It is possible to apply preload in the axial direction.

That is, in the bearing 60, the inner ring 62 is fitted to the output shaft 82b, and the inner ring 62 is in contact with the core metal part 94a of the worm wheel 94, so that the inner ring 62 of the bearing 60 is Movement to the second housing 25 is restricted.

On the other hand, in the first housing 21, the connecting portion 24c of the stepped portion 24 comes into contact with the end 251b of the retainer 150 on the side opposite to the side where the worm wheel 94 is located in the axial direction. The positional relationship is such that when the first housing 21 is connected to the second housing 25, a pressing force F can be applied from the connecting portion 24c to the end portion 251b of the retainer 250. In this case, the pressing force F applied from the connecting portion 24c to the end portion 251b of the retainer 250 is a force that moves the retainer 250 toward the side where the second housing 25 is located in the axial direction.

The pressing force F applied from the connection portion 24c of the first housing 21 to the end portion 251b of the retainer 250 acts on the entire retainer 250. Therefore, the pressing force F applied from the connection portion 24c to the retainer 250 acts on the outer ring 61 of the bearing 60 into which the retainer 250 is pressed. That is, the pressing force F applied from the connection portion 24c to the retainer 250 acts on the outer ring 61 of the bearing 60 from the retainer 250 due to the frictional force between the cylindrical portion 251 of the retainer 250 and the outer ring 61 caused by the cylindrical portion 251 being pressed into the outer ring 61 of the bearing 60. As a result, a pressing force F acts on the outer ring 61 of the bearing 60 from the cylindrical portion 251 of the retainer 250 in a direction that moves the outer ring 61 toward the side where the second housing 25 is located in the axial direction.

The outer ring 61 of the bearing 60, to which the pressing force F from the cylindrical portion 251 of the retainer 250 acts, moves in the direction in which the pressing force F acts, thereby coming into contact with the rolling element 63, and the rolling element 63 moves further in the direction in which the pressing force F acts, thereby coming into contact with the inner ring 62. As a result, the outer ring 61 of the bearing 60, to which the pressing force F acts from the retainer 250, is in a state in which it applies a preload to the rolling element 63, and the rolling element 63 is in a state in which it applies a preload to the inner ring 62.

In other words, the pressing force F acting on the retainer 250 from the connecting portion 24c of the first housing 21 is the preload that brings the outer ring 61 of the bearing 60 into contact with the rolling elements 63 and further brings the rolling elements 63 into contact with the inner ring 62. Acts as. As a result, even in the third embodiment, the bearing 60 maintains a state in which the outer ring 61 and the rolling elements 63 and the rolling elements 63 and the inner ring 62 are in contact with each other, and the gap between the outer ring 61, the inner ring 62, and the rolling elements 63 is maintained. is eliminated, and the state in which the looseness is eliminated is maintained.

As described above, in the torque sensor device 10 according to the third embodiment, the cylindrical portion 251 of the retainer 250 is press-fitted into the outer ring 61 of the bearing 60, so that movement of the bearing 60 in the axial direction with respect to the outer ring 61 is restricted. and is attached to the bearing 60. Thereby, the retainer 250 can be easily attached to the outer ring 61 of the bearing 60 in a state where movement in the axial direction is restricted. Therefore, when applying preload to the bearing 60 by bringing the connecting portion 24c of the stepped portion 24 of the first housing 21 into contact with the end portion 251b of the retainer 250, it is possible to apply the preload to the bearing 60 with a simple configuration. can. As a result, it is possible to apply preload to the bearing 60 and suppress operating noise while suppressing an increase in manufacturing costs.

In addition, the bearing 60 is placed in the first housing 21 after the retainer 250 is attached to the outer ring 61, so manufacturing costs can be kept down. In other words, a large bearing 60 is expensive, but by attaching the retainer 250 to the outer ring 61 of the bearing 60 and then placing it in the first housing 21, it is possible to adopt a small, inexpensive bearing 60. This allows for a reduction in manufacturing costs, so that the bearing 60 can be preloaded to suppress operating noise while preventing an increase in manufacturing costs.

[Modified example]
In addition, in the first embodiment described above, the outer extension part 55 and the inner extension part 56 of the retainer 50 are each formed in an annular shape, and also in the second embodiment, the inner extension part 156 of the retainer 150 is Although formed in an annular shape, the outer extension portion 55 and the inner extension portions 56 and 156 may be formed in a shape other than the annular shape. For example, the outer extension portion 55 and the inner extension portions 56, 156 may be formed to extend in the radial direction from the cylindrical portions 51, 151 intermittently in the circumferential direction. The outer extension portion 55 can receive an axial pressing force from the retainer contact portion 23 of the first housing 21, and the inner extension portions 56, 156 can receive an axial pressing force against the outer ring 61 of the bearing 60. As long as it can be given, its shape does not matter.

When the inner extensions 56, 156 are formed intermittently in the circumferential direction, the inner diameter of the inner extensions 56, 156 compared to the outer ring 61 and inner ring 62 of the bearing 60 is the radius of the distance between the inner end of the inner extensions 56, 156 in the radial direction and the axis of the cylindrical portion 51, 151, and the diameter of the circumference centered on the axis of the cylindrical portion 51, 151 is treated as the inner diameter of the inner extensions 56, 156. In other words, the distance between the inner end of the inner extensions 56, 156 in the radial direction and the axis of the cylindrical portion 51, 151 of the retainer 50, 150 is smaller than the radius of the outer diameter of the outer ring 61 of the bearing 60 and larger than the radius of the outer diameter of the inner ring 62.

Further, the inner diameter of the cylindrical portions 51, 151, 251 of the retainers 50, 150, 250 is preferably set according to the outer diameter of the bearing 60. FIG. 19 is a modification of the torque sensor device 10 according to the first embodiment, and is an explanatory diagram when a small diameter bearing 60 is used. FIG. 20 is a modification of the torque sensor device 10 according to the second embodiment, and is an explanatory diagram when a small diameter bearing 60 is used. When a bearing 60 with a small outer diameter is used for rotatably supporting the output shaft 82b of the steering shaft 82, the inner diameter of the cylindrical portions 51, 151 of the retainers 50, 150, as shown in FIGS. It is preferable to make the diameter of the outer ring 61 of the bearing 60 smaller. By making the inner diameter of the cylindrical portions 51, 151 of the retainers 50, 150 smaller to match the outer diameter of the small diameter bearing 60, even in the bearing 60 with a small outer diameter, the axial direction from the retainer 50, 150 to the bearing 60 is It is possible to apply a pressing force of . As a result, it is possible to reduce the weight by using a small diameter bearing 60 for the bearing 60 that rotatably supports the output shaft 82b. 60 can be preloaded to suppress operating noise.

In the second embodiment described above, the cylindrical portion 151 and the inner extension portion 156 of the retainer 150 are integrally formed, but the cylindrical portion 151 and the inner extension portion 156 do not have to be integrally formed. FIG. 21 is a modified example of the torque sensor device 10 according to the second embodiment, and is an explanatory diagram of a form in which the cylindrical portion 151 and the inner extension portion 156 of the retainer 150 are separated. As shown in FIG. 21, the retainer 150 may be formed by dividing the cylindrical portion 151 and the inner extension portion 156. That is, the retainer 150 may be formed by a cylindrical portion 151 such as the cylindrical portion 251 of the retainer 250 of the third embodiment and an annular inner extension portion 156. In this case, the annular inner extension portion 156 is formed with an outer diameter substantially the same as the outer diameter of the cylindrical portion 151, for example, as shown in FIG. 21.

As described above, in the case where the cylindrical portion 151 and the inner extension portion 156 of the retainer 150 are separated, the retainer 150 is assembled to the bearing 60 by first press-fitting the cylindrical portion 151 into the outer ring 61 of the bearing 60. Next, the annular inner extension portion 156 is placed on the end of the cylindrical portion 151 opposite to the side where the worm wheel 94 is located in the axial direction. Next, the connecting portion 24c of the stepped portion 24 of the first housing 21 is brought into contact with the surface of the inner extension portion 156 opposite to the side where the cylindrical portion 151 is located. Thereby, the pressing force applied from the connecting portion 24c of the first housing 21 to the inner extension portion 156 is applied to the cylindrical portion 151 of the retainer 150 and the outer ring 61 of the bearing 60 via the inner extension portion 156.

Further, the pressing force applied to the cylindrical portion 151 of the retainer 150 is caused by the frictional force between the cylindrical portion 151 and the outer ring 61 due to the cylindrical portion 151 being press-fitted into the outer ring 61 of the bearing 60. 61. Thereby, the retainer 150, which is divided into the cylindrical portion 151 and the inner extension portion 156, can apply preload to the bearing 60 and suppress operation noise. Further, the cylindrical portion 151 of the divided retainer 150 is formed in a cylindrical shape, and the inner extension portion 156 is formed in an annular shape, so that they are each formed in a simple shape. Therefore, the processing cost when processing the retainer 150 can be reduced, and the manufacturing cost when realizing a structure that applies preload to the bearing 60 can be suppressed.

In the third embodiment described above, the width of the retainer 250 in the axial direction is approximately the same as the width of the bearing 60 in the same direction, but the width of the retainer 250 may be different from the width of the bearing 60. FIG. 22 is a modified example of the torque sensor device 10 according to the third embodiment, and is an explanatory diagram showing a form in which the width of the retainer 250 in the axial direction is different from the width of the bearing 60. The width of the retainer 250 in the axial direction, i.e., the width of the cylindrical portion 251, may be narrower than the width of the bearing 60 as shown in FIG. 22, and when the cylindrical portion 251 is pressed into the outer ring 61 of the bearing 60, the axial distance between the ends 251a and 251b of the cylindrical portion 251 and the end face 65 of the outer ring 61 may be different on both sides of the cylindrical portion 251 in the axial direction. In other words, when the cylindrical portion 251 of the retainer 250 is press-fitted into the outer ring 61 of the bearing 60, the distance between one end 251a of the cylindrical portion 251 in the axial direction and the end of the outer ring 61 may be different from the distance between the other end 251b of the cylindrical portion 251 in the axial direction and the end of the outer ring 61.

For example, of the ends 251a, 251b on both sides of the cylindrical portion 251, the end 251b on the side where the connecting portion 24c of the first housing 21 abuts may be positioned in the axial direction at the same position as the end face 65 of the outer ring 61, and the end 251a on the opposite side may be positioned in the axial direction offset from the end face 65 of the outer ring 61. In this case, it is preferable that the cylindrical portion 251 is attached to the outer ring 61 including the entire axial range in which the groove portion 61a, into which the rolling element 63 fits, is formed in the outer ring 61 of the bearing 60.

In this way, by making the distances between the ends 251a, 251b of the cylindrical portion 251 and the end face 65 of the outer ring 61 different on both sides in the axial direction, it becomes easy to grasp the end 251b of the cylindrical portion 251 on the side that abuts the connection portion 24c of the first housing 21 in the bearing 60 with the cylindrical portion 251 pressed in. Therefore, when assembling the bearing 60 with the cylindrical portion 251 pressed in to the output shaft 82b, it is possible to prevent the assembly direction from being incorrect.

That is, the preload applied to the bearing 60 is applied by bringing the connecting portion 24c of the first housing 21 into contact with the end portion 251b of the cylindrical portion 251 and applying a pressing force from the connecting portion 24c to the cylindrical portion 251. Therefore, the position of the end 251b of the cylindrical portion 251 on the side that contacts the connecting portion 24c is important. For this reason, the positional relationship between the ends 251a and 251b of the cylindrical part 251 and the end surface 65 of the outer ring 61 is made different on both sides of the cylindrical part 251, and the end 251b of the cylindrical part 251 on the side where the connecting part 24c comes into contact By making it easy to grasp, the end 251b on the side that contacts the connecting portion 24c can be placed at an appropriate position. Thereby, it is possible to appropriately apply preload to the bearing 60, and it is possible to suppress operation noise.

In the above-described third embodiment, the retainer 250 is attached to the bearing 60 by press-fitting the cylindrical portion 251 into the outer ring 61 of the bearing 60, thereby restricting axial movement relative to the outer ring 61. However, the cylindrical portion 251 may be attached to the outer ring 61 by means of a method other than press-fitting. FIG. 23 is a modified example of the torque sensor device 10 according to the third embodiment, and is an explanatory diagram showing a form in which the cylindrical portion 251 of the retainer 250 is attached to the bearing 60 using a crimping portion 257 as well. The cylindrical portion 251 of the retainer 250 is press-fitted into the outer ring 61 of the bearing 60, and further, the ends 251a and 251b of the cylindrical portion 251 may be connected to the end face 65 of the outer ring 61 by the crimping portion 257 as shown in FIG. 23.

By connecting the ends 251a and 251b of the cylindrical portion 251 of the retainer 250 and the end surface 65 of the outer ring 61 of the bearing 60 by the caulking portion 257, the cylindrical portion 251 press-fitted into the outer ring 61 is prevented from shifting from the outer ring 61. Can be suppressed. Thereby, the pressing force from the first housing 21 can be appropriately applied to the outer ring 61 of the bearing 60 via the retainer 250, and a preload can be appropriately applied to the bearing 60, so that the operation Sound can be suppressed.

Figures 24 and 25 are explanatory diagrams showing an example of a method for forming the crimped portion 257 shown in Figure 23. When connecting the cylindrical portion 251 of the retainer 250 and the outer ring 61 of the bearing 60 with the crimped portion 257, crimping members 257a are provided on both ends 251a and 251b in the axial direction of the cylindrical portion 251. The crimping members 257a are formed integrally with the cylindrical portion 251. First, the cylindrical portion 251 with the crimping members 257a formed on both ends 251a and 251b is pressed into the outer ring 61 of the bearing 60 (Figures 24(a) and 25(a)).

Then, the crimping member 257a is pressed from both axial sides of the cylindrical portion 251 with the crimping machine 300 to crimp the crimping member 257a with the crimping machine 300, forming the crimped portion 257 that connects the ends 251a, 251b of the cylindrical portion 251 to the end face 65 of the outer ring 61 (Figures 24(b) and 25(b)).

At this time, the crimping surface 310 of the crimping machine 300, which presses the crimping member 257a to form the crimped part 257, has a concave shape recessed in the direction away from the cylindrical part 251 in the axial direction, as shown in FIG. Alternatively, as shown in FIG. 25, the caulking member 257a may be formed in a slope shape that allows the caulking member 257a to be tilted toward the outer ring 61. As described above, by forming the caulking part 257 using the caulking machine 300 and connecting the cylindrical part 251 of the retainer 250 and the outer ring 61 of the bearing 60 by the caulking part 257, the cylindrical part press-fitted into the outer ring 61 is formed. 251 from the outer ring 61 can be suppressed.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to those described in the above embodiments. The configurations described as embodiments and modified examples may be combined as appropriate.

REFERENCE SIGNS LIST 10, 200 Torque sensor device 20 Housing 21 First housing 22, 26 Inner circumferential surface 23 Retainer abutment portion 24 Step portion 24a Large diameter portion 24b Small diameter portion 24c Connection portion 25 Second housing 30 Torque detection portion 31 Magnet 32 First sleeve 34 Stator 34a First stator 34b Second stator 35 Flange portion 36 Teeth portion 37 Second sleeve 38 Carrier 40 Sensor housing 41 Magnetic flux collecting yoke 43 Hall IC
Reference Signs List 44 Circuit board 50, 150, 250 Retainer 51, 151, 251 Cylindrical portion 51a, 51b, 151b, 251b End portion 52, 152 Outer peripheral surface 53 Inner peripheral surface 55 Outer extension portion 56, 156 Inner extension portion 60, 68 Bearing 61, 68a Outer ring 62, 68b Inner ring 63, 68c Rolling element 64 Outer peripheral surface 65 End surface 80 Steering device 81 Steering wheel 82 Steering shaft 82a Input shaft 82aa Insertion hole 82b Output shaft 82ba Through hole 82bb Connection hole 82c Torsion bar 84, 86 Universal joint 85 Intermediate shaft 87 Pinion shaft 88 Steering gear 88a Pinion gear 88b Rack bar 89 Tie rod 90 ECU
Reference Signs List 91 Electric motor 92 Reduction gear 93 Worm 94 Worm wheel 95 Vehicle speed sensor 98 Ignition switch 99 Power supply device 100 Pin 210 Preload applying member

Claims (11)

A stator fixed to the shaft;
A cylindrical magnet disposed opposite the stator;
a housing in which the shaft, the stator, and the magnets are disposed;
a bearing that rotatably supports the shaft relative to the housing;
a retainer interposed between the housing and the bearing;
Equipped with
The bearing includes an outer ring, an inner ring, and a plurality of rolling elements disposed between the outer ring and the inner ring,
The retainer has a cylindrical portion formed in a cylindrical shape,
an inner peripheral surface of the cylindrical portion faces an outer peripheral surface of the bearing, and an outer peripheral surface of the cylindrical portion faces an inner peripheral surface of the housing,
the cylindrical portion is attached to the bearing such that movement of the cylindrical portion relative to the outer ring in an axial direction of the bearing is restricted,
The housing is a torque sensor device that abuts against a surface of the cylindrical portion of the retainer that faces in the axial direction. The retainer includes an inner extension portion that extends inward in the radial direction of the cylindrical portion from an end in the axial direction of the cylindrical portion, and an inner extension portion that extends inward in the radial direction of the cylindrical portion, and a an outer extension extending outward in the radial direction of the cylindrical portion from the end;
The surface of the inner extension part on the side where the cylindrical part is located in the axial direction of the cylindrical part abuts the end face of the outer ring in the axial direction of the bearing, so that the cylindrical part moves in the axial direction of the bearing with respect to the outer ring. mounted on the bearing with movement regulated;
The surface of the outer extension part on the side where the cylindrical part is located in the axial direction of the cylindrical part abuts on the retainer abutting part, which is a part of the housing facing in the axial direction of the cylindrical part. The torque sensor device according to claim 1, wherein the housing contacts an axially facing surface of the cylindrical portion of the retainer. The torque according to claim 2, wherein the housing applies a preload in the axial direction of the bearing from the retainer to the outer ring of the bearing when the retainer contact portion abuts the outer extension portion of the retainer. sensor device. the retainer has an inner extension portion extending radially inward from an axial end of the cylindrical portion,
a surface of the inner extension portion on a side where the cylindrical portion is located in an axial direction of the cylindrical portion abuts against an end surface of the outer ring in the axial direction of the bearing, so that the cylindrical portion is attached to the bearing while movement of the cylindrical portion in the axial direction relative to the outer ring is restricted,
the housing has a large diameter portion whose inner peripheral surface faces an outer peripheral surface of the cylindrical portion of the retainer, a small diameter portion whose inner diameter is smaller than the inner diameter of the large diameter portion, and a connection portion that connects the large diameter portion and the small diameter portion and faces an end face of the outer ring in the axial direction of the bearing,
2. The torque sensor device according to claim 1, wherein the connection portion abuts against an end portion of the cylindrical portion of the retainer on the axial side where the inner extension portion is located, so that the housing abuts against a surface of the cylindrical portion of the retainer facing in the axial direction. The torque sensor device according to claim 4, wherein the housing applies a preload in the axial direction of the bearing from the retainer to the outer ring of the bearing by the connection portion abutting against the end of the cylindrical portion of the retainer on the side where the inner extension portion is located in the axial direction. The torque sensor device according to claim 2 or 4, wherein the inner diameter of the inner extension of the retainer is smaller than the outer diameter of the outer ring and larger than the outer diameter of the inner ring. The torque sensor device according to claim 1, wherein the cylindrical portion is press-fitted into the outer ring, thereby restricting the axial movement of the bearing relative to the outer ring and attaching the bearing to the bearing. When the cylindrical portion is press-fitted into the outer ring, the cylindrical portion has a distance between one end of the cylindrical portion in the axial direction and an end of the outer ring, and a distance between the other end of the cylindrical portion in the axial direction and the outer ring. 8. The torque sensor device according to claim 7, wherein the distances from the ends of the torque sensor apparatus are different from each other. The torque sensor device according to claim 1, wherein the outer diameter of the bearing is equal to or smaller than the outer diameter of the stator. The torque sensor device according to claim 1, wherein the outer diameter of the cylindrical portion of the retainer is larger than the outer diameter of the stator. a steering shaft including an input shaft, an output shaft, and a torsion bar disposed inside the input shaft and the output shaft to connect the input shaft and the output shaft;
a stator attached to either the input shaft or the output shaft;
a cylindrical magnet attached to the other of the input shaft or the output shaft and arranged to face the stator;
a first housing in which the steering shaft, the stator, and the magnet are disposed;
a first bearing that rotatably supports the output shaft relative to the first housing;
a retainer interposed between the first housing and the first bearing;
an electric motor that generates an auxiliary steering torque;
a worm wheel fixed to the output shaft and configured to transmit an auxiliary steering torque generated by the electric motor to the output shaft;
a second housing that is connected to the first housing and is located closer to the output shaft in the axial direction of the steering shaft than the first housing, and in which the steering shaft and the worm wheel are disposed inside;
a second bearing that is disposed on an opposite side of the first bearing with respect to the worm wheel in the axial direction of the steering shaft and supports the output shaft rotatably with respect to the second housing;
Equipped with
The first bearing has an outer ring, an inner ring, and a plurality of rolling elements disposed between the outer ring and the inner ring,
The retainer has a cylindrical portion formed in a cylindrical shape,
an inner circumferential surface of the cylindrical portion faces an outer circumferential surface of the first bearing, and an outer circumferential surface of the cylindrical portion faces an inner circumferential surface of the first housing,
the cylindrical portion is attached to the first bearing such that movement of the first bearing relative to the outer ring in an axial direction is restricted,
The first housing abuts against a surface of the cylindrical portion of the retainer that faces in the axial direction.

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