Rotation limiting device and steering device

Abstract

This rotation limiting device comprises: a first member having a first protuberance; a second member which has a second protuberance disposed further toward an axial-direction one side than the first protuberance, and which is disposed at the periphery of the first member so as to be capable of rotating relative to the first member; a side plate portion disposed between the first protuberance and the second protuberance in the axial direction; at least one intermediate member which has an intermediate-side first protuberance that protrudes from an axial-direction other side surface of the side plate portion toward an axial-direction other side, and an intermediate-side second protuberance that protrudes from an axial-direction one side surface of the side plate portion toward the axial-direction one side, is disposed between the first member and the second member in a radial direction, and is supported so as to be capable of rotating relative to the first member and the second member; and a rotation support mechanism which supports the second member at the periphery of the first member so as to be capable of rotating relative to the first member.

Description

[Technical Field]

[0001] The present disclosure relates to a rotation limiting device for limiting the amount of rotation of a rotating member, and a steering device. [Background technology]

[0002] In a rack-and-pinion steering device, when the steering wheel is turned (turned) to the maximum right or left, the rack end, which is supported and fixed to the end of the rack shaft, hits the housing. In this way, in a rack-and-pinion steering device in which the steering unit and the steering unit are mechanically connected, the number of lock-to-lock rotations of the steering wheel (the number of rotations of the steering wheel when the steering wheel is turned from the maximum right or left to the maximum left or right) is limited by limiting the stroke of the rack shaft that constitutes the steering unit.

[0003] In contrast, in a steer-by-wire steering system, the steering unit and the turning unit are not mechanically connected, so it is not possible to limit the lock-to-lock rotation speed of the steering wheel that constitutes the steering unit by limiting the stroke of the rack shaft that constitutes the turning unit.

[0004] Figure 14 shows a stopper unit 100 for mechanically limiting the lock-to-lock rotation speed of a steering wheel in a steer-by-wire steering device described in Patent Document 1. Note that Figure 14 is a representation of Figure 4 of JP 2020-69844 A, with the left and right sides reversed (left and right symmetrical). The stopper unit 100 includes a first rotating member 101, a housing 102, and a second rotating member 103.

[0005] The first rotating member 101 has a first rotating protrusion 104 that protrudes toward one axial direction on one axial side (the left side in FIG. 14). The first rotating member 101 is connected and fixed to the tip end (the other axial end) of a steering shaft (not shown) so as not to rotate relative to it. In other words, the first rotating member 101 rotates integrally with the steering shaft as the steering wheel is operated.

[0006] The housing 102 has a fixing protrusion 105 that protrudes toward the other axial direction on the other axial side (the right side in FIG. 14) and does not rotate even during use. The steering shaft is supported radially inside the housing 102 so as to be rotatable relative to the housing 102.

[0007] The second rotating member 103 has a cylindrical portion 106 and a second rotating protrusion 107 that protrudes radially outward from one circumferential position on the outer circumferential surface of the cylindrical portion 106. The second rotating member 103 is supported around the steering shaft so as to be rotatable relative to the steering shaft, the first rotating member 101, and the housing 102.

[0008] That is, the steering shaft is inserted through the housing 102 and the second rotating member 103 from one axial side to the other axial side, and the first rotating member 101 is coupled and fixed to the tip of the steering shaft that protrudes from the end face of the second rotating member 103 on the other axial side. In addition, a steering wheel is supported and fixed to the end of one axial side of the steering shaft.

[0009] In a steering device including the stopper unit 100, for example, when the steering wheel is turned to the right (rotated clockwise as viewed from the left side of FIG. 14), first, the first rotating member 101 rotates together with the steering shaft from the top to the bottom of FIG. 14. Then, one circumferential side surface of the first rotating protrusion 104 (the bottom side surface in FIG. 14) collides with the other circumferential side surface of the other axial side portion of the second rotating protrusion 107 (the top side surface in FIG. 14).

[0010] From this state, when the steering wheel is turned further to the right, the second rotating member 103 rotates together with the steering shaft and the first rotating member 101 from the top to the bottom in FIG. 14. Then, one circumferential side surface of one axial side portion of the second rotating protrusion 107 abuts against the other circumferential side surface of the fixed protrusion 105. This prevents the steering wheel from being turned further to the left.

[0011] Patent Document 2 discloses a small and lightweight multi-rotation limit mechanism that aims to detect rotation limit operation with high accuracy without using a reduction gear mechanism. This multi-rotation limit mechanism includes a rotating shaft rotatably mounted on a bearing plate and having a rotation stopper fixed thereto, a plurality of idle rotors that are loosely fitted on the rotating shaft and rotated by the rotation stopper, a stopper rotor that is loosely fitted on the rotating shaft and engages with the idle rotors, a pair of spring members that bias the stopper portion of the stopper rotor in both rotational directions, an electrical sensor for detecting the stopper portion, and engaging pieces that are provided on the rotation stopper, idle rotor, and stopper rotor for engaging with each other.

[0012] Patent Document 3 discloses a steering device designed to maintain a constant position of a striking sound generated when an operating member is rotated left or right from a neutral position. This steering device rotatably holds an operating member that is not mechanically connected to a steered wheel. The steering device also includes a shaft member that rotates in response to operation of the operating member, a holding member that rotatably holds the shaft member, a rotary engagement member attached to the shaft member and including a rotary pawl that rotates integrally with the shaft member, a fixed pawl that is positioned so as not to engage with the rotary pawl and fixed to the holding member, an intermediate engagement member that rotates about the axis of the shaft member by engaging with the rotary engagement member and includes an intermediate pawl that engages with the rotary pawl and the fixed pawl in the circumferential direction, and a biasing member that applies a biasing force to maintain the intermediate pawl at a predetermined position in the circumferential direction relative to the fixed pawl when not engaged with the rotary pawl.

[0013] Patent Document 4 discloses a steer-by-wire type power steering device. This power steering device is provided with a rotation restriction mechanism that restricts the steering angle range of the steering wheel. The rotation restriction mechanism has an integrally rotating part that rotates integrally with the second input shaft, a relative rotating part that rotates relative to the integrally rotating part, and a stopper mechanism that restricts the rotation of the relative rotating part.

[0014] Patent Document 5 discloses a steer-by-wire steering device. This steering device includes a first rotating member connected to the steering shaft and rotating in conjunction with it, a second rotating member supported on the outer periphery of the first rotating member and rotating in conjunction with the first rotating member when the steering shaft rotates, and a housing that houses the first and second rotating members, is connected to the steering column, and the outer periphery of the second rotating member is supported on the inner periphery to limit the rotation of the second rotating member. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] Japanese Patent Application Publication No. 2020-69844 [Patent Document 2] Japanese Patent Publication No. 05-042437 [Patent Document 3] Japanese Patent Publication No. 2021-172231 [Patent Document 4] Japanese Patent Application Publication No. 2006-182078 [Patent Document 5] U.S. Patent Publication No. 20220266895 Summary of the Invention [Problem to be solved by the invention]

[0016] The stopper unit 100 described in Patent Document 1 supports a first rotating member 101 and a second rotating member 103 around the steering shaft so that they can rotate relative to each other, and before the steering shaft is rotatably supported radially inside the housing 102, the first rotating member 101, the housing 102, and the second rotating member 103 are separated. This makes parts management and assembly work complicated.

[0017] The multiple rotation limit mechanism of Patent Document 2 is a device for detecting the rotation end of the rotating shaft, and is not intended to lock the rotation of the rotating shaft.

[0018] As with Patent Document 1, in the steering device of Patent Document 3, the retaining member, the rotating engagement member, and the intermediate engagement member are separate before being supported on the steering shaft, which makes parts management and assembly work complicated.

[0019] Similarly, in the power steering device of Patent Document 4, the integrally rotating portion, the relative rotating portion, and the stopper mechanism are separated before being supported on the steering shaft, which makes parts management and assembly work complicated.

[0020] Similarly, in the steering device of Patent Document 5, the first rotating member, the second rotating member, and the housing are separate before being supported by the steering shaft, which makes parts management and assembly work complicated.

[0021] In view of the above circumstances, the present disclosure aims to realize a rotation limiting device that can be pre-assembled and assembled before being attached between a rotating member and a fixed part. [Means for solving the problem]

[0022] A rotation limiting device according to one aspect of the present disclosure includes a first member, a second member, at least one intermediate member, and a rotation support mechanism.

[0023] The first member has a first projection.

[0024] The second member has a second protrusion disposed on one axial side of the first protrusion, and is disposed around the first member so as to be rotatable relative to the first member.

[0025] The at least one intermediate member has a side plate portion disposed between the first protrusion and the second protrusion in the axial direction, a first intermediate protrusion protruding from the other axial side surface of the side plate portion toward the other axial side, and a second intermediate protrusion protruding from one axial side surface of the side plate portion toward one axial side. The at least one intermediate member is disposed between the first member and the second member in the radial direction and is supported so as to be rotatable relative to the first member and the second member.

[0026] The rotation support mechanism supports the second member around the first member so as to be rotatable relative to the first member.

[0027] In a rotation limiting device according to one embodiment of the present disclosure, the first member may have a first side facing one axial side and the first protrusion protruding from the first side toward the one axial side, and the second member may have a second side facing the other axial side and the second protrusion protruding from the second side toward the other axial side.

[0028] In a rotation limiting device according to one embodiment of the present disclosure, the second member may have a second cylindrical portion and a second flange portion protruding radially inward from the inner peripheral surface of the second cylindrical portion, and the second flange portion may have the second side surface on the other axial side surface.

[0029] In a rotation limiting device according to one embodiment of the present disclosure, the first member may have a first cylindrical portion into which the at least one intermediate member is externally fitted so as to be rotatable relative to one another, and a first flange portion protruding radially outward from the outer peripheral surface of the first cylindrical portion, and the first flange portion may have the first side surface on one axial side surface.

[0030] In a rotation limiting device according to one embodiment of the present disclosure, the rotation support mechanism may include a radial rolling bearing having an inner ring fitted onto the outside of the first member, an outer ring fitted onto the inside of the second member, and a plurality of rolling elements arranged to roll freely between the inner ring and the outer ring.

[0031] A steering device according to one aspect of the present disclosure includes a steering shaft and a rotation limiting device that limits the amount of rotation of the steering shaft to a predetermined value.

[0032] The rotation limiting device is configured by a rotation limiting device according to one aspect of the present disclosure.

[0033] One of the first member and the second member is connected and fixed to the steering shaft, and the other of the first member and the second member is supported and fixed to a part that does not rotate even when in use. [Effects of the Invention]

[0034] According to one aspect of the present disclosure, the rotation limiting device can be pre-assembled into an assembly before being attached between the rotating member and the fixed portion. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is a schematic diagram showing an example of a steer-by-wire steering system including a rotation limiting device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view showing a rotation limiting device according to a first embodiment of the present disclosure. [Figure 3] FIG. 3 is an exploded perspective view showing a rotation limiting device according to a first embodiment of the present disclosure. [Figure 4] 4(A) to 4(C) are schematic diagrams for explaining the operation of the rotation limiting device when the steering wheel is operated from the maximum left to the maximum right. [Figure 5]5(A) to 5(C) are schematic diagrams for explaining the operation of the rotation limiting device when the steering wheel is operated from the maximum right to the maximum left. [Figure 6] FIG. 6 is a cross-sectional view showing a modification of the first example of the embodiment of the present disclosure. [Figure 7] 7(A) to 7(D) are schematic diagrams for explaining the operation of the rotation limiting device in the modified example when the steering wheel is operated from the maximum left to the maximum right. [Figure 8] 8(A) to 8(D) are schematic diagrams for explaining the operation of the rotation limiting device in the modified example when the steering wheel is turned from the maximum right to the maximum left. [Figure 9] FIG. 9 is a cross-sectional view showing a rotation limiting device according to a second embodiment of the present disclosure. [Figure 10] FIG. 10 is a cross-sectional view showing a rotation limiting device according to a third embodiment of the present disclosure. [Figure 11] FIG. 11 is an exploded perspective view showing a rotation limiting device according to a third embodiment of the present disclosure. [Figure 12] FIG. 12 is a cross-sectional view illustrating a rotation limiting device according to a fourth embodiment of the present disclosure. [Figure 13] FIG. 13 is an exploded perspective view showing a rotation limiting device according to a fourth embodiment of the present disclosure. [Figure 14] FIG. 14 is an exploded view showing a stopper unit of a conventional structure. DETAILED DESCRIPTION OF THE INVENTION

[0036] [First example of embodiment] A first example of an embodiment of the present disclosure will be described with reference to Figures 1 to 5(C). In this example, a rotation limiting device 4 is incorporated into a steering unit 3 constituting the steering device 1 in order to limit the lock-to-lock rotation speed of a steering wheel 2 of a steer-by-wire steering device 1. First, the overall structure of the steering device 1 will be described below, followed by the structure and operation of the rotation limiting device 4.

[0037] <Overall structure of steering device 1> As shown in Fig. 1, the steering device 1 includes a steering unit 3 having a steering wheel 2, a steering unit 6 that applies a steering angle to a pair of steered wheels 5, and a control unit (ECU) 7. The steering device 1 has a linkless structure in which the steering unit 3 and the steering unit 6 are not mechanically connected, but are electrically connected via the control unit 7.

[0038] The steering unit 3 includes a steering column 8, a steering shaft 9, a reaction force applying device 10, and a rotation limiting device 4.

[0039] The steering column 8 has a cylindrical shape and is supported by the vehicle body.

[0040] The steering shaft 9 is rotatably supported on the radially inner side of the steering column 8. The steering wheel 2 is supported and fixed to the rear end of the steering shaft 9.

[0041] The reaction force applying device 10 is connected to the front end of the steering shaft 9. The reaction force applying device 10 includes a reaction force applying motor and a reducer such as a worm reducer, and applies the output torque of the reaction force applying motor to the steering shaft 9 after increasing it with the reducer.

[0042] The rotation limiting device 4 is provided between the steering shaft 9 and a portion that does not rotate even when in use, and limits the number of lock-to-lock rotations of the steering wheel 2. In this example, the rotation limiting device 4 is provided between the front portion of the steering shaft 9 and the front end of the steering column 8. However, the rotation limiting device 4 can be provided anywhere between the steering shaft 9 and a fixed portion that does not rotate even when in use. Specifically, the rotation limiting device 4 can be provided in a portion closer to the steering wheel 2, for example, between the rear portion of the steering shaft 9 and the rear end of the steering column 8. Alternatively, the rotation limiting device 4 can be provided between the front end of the steering shaft 9 and the housing of the reaction force applying device 10. By disposing the rotation limiting device 4 between the front end of the steering shaft 9 and the housing of the reaction force applying device 10, the rotation limiting device 4 can be attached and removed relatively easily. The specific configuration of the rotation limiting device 4 will be described later.

[0043] The steering unit 3 further includes sensors such as a torque sensor and a steering angle sensor that measure the operation of the steering wheel 2 by the driver.

[0044] The steering unit 6 includes a gear housing 11 supported and fixed to the vehicle body, a linear motion member, and a steering actuator 12 that linearly drives the linear motion member.

[0045] The linear motion member is composed of a rack shaft, a screw shaft, etc. The linear motion member has its axial direction oriented in the width direction of the vehicle body and is supported inside the gear housing 11 so as to be able to move linearly in the axial direction. Base ends of a pair of tie rods 13 are connected to both axial ends of the linear motion member via spherical joints (not shown), and a pair of steered wheels 5 are supported at the tip ends of the pair of tie rods 13.

[0046] When the linear motion member is constituted by a rack shaft, the steering actuator 12 includes a pinion shaft that meshes with the rack shaft, a steering motor, and a reducer, and the output torque of the steering motor is increased by the reducer and then input to the pinion shaft, which is then rotationally driven to cause linear movement of the rack shaft.

[0047] When the linear motion member is formed by a screw shaft, steering actuator 12 includes a nut supported around the screw shaft so as to be rotatable relative to the screw shaft, a steering motor, and a reducer. Steering actuator 12 linearly moves the screw shaft by increasing the output torque of the steering motor using the reducer and then inputting it to the nut, which rotates and drives the nut. The feed screw mechanism including the screw shaft and the nut can be formed by a slide screw type feed screw mechanism in which a male threaded portion on the outer peripheral surface of the screw shaft is directly threadedly engaged with a female threaded portion on the inner peripheral surface of the nut, or by a ball screw type feed screw mechanism in which a plurality of balls are freely rollably arranged between an inner diameter side ball screw groove on the outer peripheral surface of the screw shaft and an outer diameter side ball screw groove on the inner peripheral surface of the nut.

[0048] In the steering device 1 of this example, when the driver operates the steering wheel 2, the operation of the steering wheel 2 is measured by a sensor in the steering unit 3, and the measurement results are output to the control unit 7. Various signals indicating the driving situation, such as the steering torque measured by a torque sensor, the steering angle measured by a steering angle sensor, the vehicle speed, the yaw rate, and the acceleration, are input to the control unit 7. The control unit 7 drives the steering actuator 12 provided in the steering unit 6 based on the various signals indicating the driving situation. As a result, the linearly moving member is displaced in the width direction of the vehicle body, and the pair of tie rods 13 are pushed and pulled, thereby applying a steering angle to the pair of steered wheels 5.

[0049] <Structure of rotation limiting device 4> The rotation limiting device 4 of this example is provided between the front portion of the steering shaft 9 and the steering column 8, which does not rotate even when in use, and limits the lock-to-lock rotation speed of the steering wheel 2 by limiting the amount of rotation of the steering shaft 9 to a predetermined value. In this example, the rotation limiting device 4 includes a first member 14, a second member 15, one intermediate member 16, and a rotation support mechanism 17.

[0050] In the following description, including this example, one axial side refers to the front side of the vehicle, which is the left side in Figures 2 to 13, and the other axial side refers to the rear side of the vehicle, which is the right side in Figures 2 to 13.

[0051] The first member 14 has a first protrusion 18 .

[0052] In this example, the first member 14 has a first cylindrical portion 19 and a hollow circular plate-shaped first flange portion 20 that protrudes radially outward from the outer peripheral surface of the other axial end of the first cylindrical portion 19.

[0053] The first cylindrical portion 19 is fixed to the front portion of the steering shaft 9 so as not to rotate relative to it. In other words, the first member 14 rotates together with the steering shaft 9. In this example, the first cylindrical portion 19 has a stepped cylindrical outer surface formed by connecting a large-diameter cylindrical portion 21 on the other axial side and a small-diameter cylindrical portion 22 on one axial side by an inner-diameter stepped surface 23 facing one axial side. The large-diameter cylindrical portion 21 is formed of a cylindrical surface whose outer diameter does not change in the axial direction. The small-diameter cylindrical portion 22 is formed of a cylindrical surface whose outer diameter does not change in the axial direction, except for an inner-diameter locking groove 24 provided around the entire circumference on one axial side portion. The inner-diameter stepped surface 23 is formed of a flat surface perpendicular to the central axis O of the first member 14.

[0054] The first flange portion 20 has a first side surface 25 on one axial side surface, and a first protrusion 18 protruding toward one axial side at one circumferential position on the radially outer portion of the first side surface 25. The radially inner surface of the first protrusion 18 faces the end portion on the other axial side of the large-diameter cylindrical surface portion 21 via a gap.

[0055] In this example, the first projection 18 has a fan-shaped end face shape when viewed from one axial side. That is, the radially inner and outer surfaces of the first projection 18 have an arc-shaped outline centered on the central axis O of the first member 14 when viewed from one axial side. The radially outer surface of the first projection 18 exists within the same cylindrical surface as the outer circumferential surface of the first flange portion 20. That is, the first projection 18 does not protrude radially outward beyond the first flange portion 20. The side surfaces on both circumferential sides of the first projection 18 have a linear outline shape extending in the radial direction centered on the central axis O of the first member 14 when viewed from one axial side, and extend linearly in the axial direction when viewed from the radially outer side. That is, the side surfaces on both circumferential sides of the first projection 18 exist within an imaginary plane including the central axis O of the first member 14. Furthermore, in this example, the circumferential width of the first projection 18, i.e., the angle formed by the side surfaces on both circumferential sides, is 45 degrees.

[0056] The second member 15 has a second protrusion 26 arranged on one axial side of the first protrusion 18, and is arranged around the first member 14 coaxially with the first member 14 and capable of relative rotation with respect to the first member 14.

[0057] In this example, the second member 15 has a second cylindrical portion 27 and a second flange portion .

[0058] The second cylindrical portion 27 has a stepped cylindrical shape formed by connecting a large-diameter cylindrical portion 29 on the other axial side and a small-diameter cylindrical portion 30 on one axial side by a connecting plate portion 31 in the form of a hollow circular plate.

[0059] Of the large diameter cylindrical portion 29, the inner surface of the other axial side portion, excluding the end portion on one axial side to which the radially outer end portion of the second protrusion 26 is connected, is composed of a cylindrical surface whose inner diameter does not change in the axial direction.

[0060] The small diameter cylindrical portion 30 has an outer diameter step surface 32 facing one axial side at the other axial end of the inner peripheral surface, and has an outer diameter locking groove 33 around the entire circumference on one axial side portion of the inner peripheral surface.

[0061] The second flange portion 28 protrudes radially inward from the inner circumferential surface of the connecting plate portion 31 over the entire circumference. That is, the second flange portion 28 is configured in a hollow circular shape. The second flange portion 28 has a second side surface 34 on the other axial side surface, and has a second protrusion 26 at one position on the radially outer portion of the second side surface 34. The radially outer end of the second protrusion 26 is connected to an end on one axial side of the inner circumferential surface of the large-diameter cylindrical portion 29.

[0062] In this example, the second projection 26 has a fan-shaped end face shape when viewed from the other axial side. That is, the radially inner and outer surfaces of the second projection 26 have an arc-shaped outline shape centered on the central axis O of the second member 15 when viewed from the other axial side. The side surfaces on both circumferential sides of the second projection 26 have a linear outline shape extending in the radial direction centered on the central axis O of the second member 15 when viewed from the other axial side, and extend linearly in the axial direction when viewed from the radially inner side. That is, the side surfaces on both circumferential sides of the second projection 26 exist within an imaginary plane including the central axis O of the second member 15. Furthermore, in this example, the circumferential width of the second projection 26 is 45 degrees.

[0063] The second member 15 further has a pair of ears 35 that protrude radially outward from two radially opposite positions on the other axial end of the large-diameter cylindrical portion 29 of the second cylindrical portion 27. Each ear 35 has a connecting hole 36 that penetrates in the axial direction. In this example, the connecting holes 36 are configured as cylindrical holes whose inner diameter does not change in the axial direction. The rotation limiting device 4 of this example is supported and fixed to the steering column 8, which does not rotate even during use, by threading connecting bolts that are inserted through the connecting holes 36 of the pair of ears 35 of the second member 15 into column-side threaded holes that open on the front side of the steering column 8.

[0064] The intermediate member 16 has a side plate portion 37 that is arranged between the first projection 18 and the second projection 26 in the axial direction, a first intermediate projection 38 that projects toward the other axial direction from the other axial side surface of the side plate portion 37, and a second intermediate projection 39 that projects toward one axial direction from one axial side surface of the side plate portion 37. The intermediate member 16 is supported coaxially with the first member 14 and the second member 15 and capable of relative rotation with respect to the first member 14 and the second member 15.

[0065] In this example, the intermediate member 16 has a cylindrical intermediate tubular portion 40 that is externally fitted onto the first tubular portion 19 of the first member 14 so as to be rotatable relative to the first tubular portion 19, and a hollow circular plate-shaped side plate portion 37 that protrudes radially outward from the outer peripheral surface of the axial middle portion of the intermediate tubular portion 40.

[0066] Furthermore, the intermediate member 16 has a first intermediate-side protrusion 38 that protrudes toward the other axial side from one circumferential position on the other axial side surface of the side plate portion 37, and has a second intermediate-side protrusion 39 that protrudes toward one axial side from one position on one axial side surface of the side plate portion 37 that is radially opposite to the first intermediate-side protrusion 38 (one position that is 180 degrees out of phase with the first intermediate-side protrusion 38 in the circumferential direction). A radially inner end of the first intermediate-side protrusion 38 is connected to the other axial side portion of the outer circumferential surface of the intermediate tubular portion 40, and a radially inner end of the second intermediate-side protrusion 39 is connected to the one axial side portion of the outer circumferential surface of the intermediate tubular portion 40.

[0067] In this example, the intermediate-side first protrusion 38 has a fan-shaped end face shape when viewed from the other axial side. That is, the radially inner surface and the radially outer surface of the intermediate-side first protrusion 38 have an arc-shaped contour centered on the central axis O of the intermediate member 16 when viewed from the other axial side. The radially outer surface of the intermediate-side first protrusion 38 is located within the same cylindrical plane as the outer peripheral surface of the side plate portion 37. That is, the intermediate-side first protrusion 38 is formed integrally with the side plate portion 37 and does not protrude radially outward beyond the side plate portion 37. That is, the intermediate-side first protrusion 38 is located radially inward beyond the outer peripheral surface of the side plate portion 37. Note that the radially outer surface of the intermediate-side first protrusion 38 does not necessarily have to be located within the same cylindrical plane as the outer peripheral surface of the side plate portion 37, as long as it is located radially inward beyond the outer peripheral surface of the side plate portion 37. The side surfaces on both circumferential sides of the intermediate-side first projection 38 have a linear outline shape extending in a radial direction centered on the central axis O of the intermediate member 16 when viewed from the other axial side, and extend linearly in the axial direction when viewed from the radially outer side. In other words, the side surfaces on both circumferential sides of the intermediate-side first projection 38 exist within an imaginary plane including the central axis O of the intermediate member 16. In this example, the circumferential width of the intermediate-side first projection 38 is 45 degrees.

[0068] In this example, the intermediate-side second protrusion 39 has a fan-shaped end face shape when viewed from one axial side. That is, the radially inner surface and the radially outer surface of the intermediate-side second protrusion 39 have an arc-shaped contour centered on the central axis O of the intermediate member 16 when viewed from one axial side. The radially outer surface of the intermediate-side second protrusion 39 is located within the same cylindrical plane as the outer peripheral surface of the side plate portion 37. That is, the intermediate-side second protrusion 39 is formed integrally with the side plate portion 37 and does not protrude radially outward beyond the side plate portion 37. That is, the intermediate-side second protrusion 39 is located radially inward beyond the outer peripheral surface of the side plate portion 37. Note that the radially outer surface of the intermediate-side second protrusion 39 does not necessarily have to be located within the same cylindrical plane as the outer peripheral surface of the side plate portion 37, as long as it is located radially inward beyond the outer peripheral surface of the side plate portion 37. The side surfaces on both circumferential sides of the intermediate-side second projection 39 have a linear outline shape extending in a radial direction centered on the central axis O of the intermediate member 16 when viewed from one axial side, and extend linearly in the axial direction when viewed from the radially outer side. In other words, the side surfaces on both circumferential sides of the intermediate-side second projection 39 exist within an imaginary plane including the central axis O of the intermediate member 16. In this example, the circumferential width of the intermediate-side second projection 39 is 45 degrees.

[0069] The rotation support mechanism 17 supports the second member 15 around the first member 14 so as to allow relative rotation with respect to the first member 14 and to prevent inadvertent separation. In this example, the rotation support mechanism 17 is disposed between the small-diameter cylindrical surface portion 22 of the first member 14 and the inner circumferential surface of the small-diameter cylindrical portion 30 of the second member 15.

[0070] In this example, the rotation support mechanism 17 includes a radial rolling bearing 41 and two snap rings 42a and 42b each having a segmented annular shape (having a C-shaped end face when viewed in the axial direction).

[0071] The radial rolling bearing 41 has an inner ring 43 , an outer ring 44 , and a plurality of rolling elements 45 .

[0072] The inner ring 43 has an inner ring raceway 46 on its outer peripheral surface, and is fitted onto the small-diameter cylindrical surface portion 22 of the first member 14 without any rattle. The other axial side surface of the inner ring 43 abuts against the inner diameter side stepped surface 23, and one axial side surface abuts against the retaining ring 42a engaged in the inner diameter side engaging groove 24. In other words, the inner ring 43 is sandwiched in the axial direction between the inner diameter side stepped surface 23 and the retaining ring 42a engaged in the inner diameter side engaging groove 24. This allows the inner ring 43 to be positioned relative to the first member 14.

[0073] The outer ring 44 has an outer ring raceway 47 on its inner peripheral surface, and is fitted securely into the small-diameter cylindrical portion 30 of the second member 15. The other axial side surface of the outer ring 44 abuts against the outer-diameter-side stepped surface 32, and one axial side surface abuts against the retaining ring 42b engaged in the outer-diameter-side locking groove 33. In other words, the outer ring 44 is sandwiched in the axial direction between the outer-diameter-side stepped surface 32 and the retaining ring 42b engaged in the outer-diameter-side locking groove 33. This allows the outer ring 44 to be positioned relative to the second member 15.

[0074] Each rolling element 45 is disposed so as to roll freely between an inner ring raceway 46 of the inner ring 43 and an outer ring raceway 47 of the outer ring 44. In this example, balls are used as the rolling elements 45. That is, the radial rolling bearing 41 is constituted by a radial ball bearing.

[0075] The rotation limiting device 4 in this example is assembled by externally fitting the intermediate tubular portion 40 of the intermediate member 16 onto the large diameter cylindrical surface portion 21 of the first member 14 without any rattle so that they can rotate relative to each other, and by arranging the second member 15 around the first member 14 and the intermediate member 16, and then arranging the rotation support mechanism 17 between the small diameter cylindrical surface portion 22 of the first member 14 and the inner surface of the small diameter cylindrical portion 30 of the second member 15.

[0076] In addition, when the rotation limiting device 4 is in an assembled state, the inner circumferential surface of the large-diameter cylindrical portion 29 of the second member 15 faces, via gaps, the outer circumferential surface of the first flange portion 20 of the first member 14 and the radially outer side surfaces of the first protrusions 18, and the outer circumferential surface of the side plate portion 37 of the intermediate member 16, the radially outer side surfaces of the intermediate-side first protrusions 38, and the radially outer side surfaces of the intermediate-side second protrusions 39, and the inner circumferential surface of the second flange portion 28 faces, via a gap, an end portion on one axial side of the large-diameter cylindrical surface portion 21 of the first member 14. In addition, the radially inner portion of the first side surface 25 is in sliding contact with or closely faces the end face on the other axial side of the intermediate cylindrical portion 40, and the radially inner portion of the second side surface 34 is in sliding contact with or closely faces the end face on one axial side of the intermediate cylindrical portion 40. One axial side surface of the first projection 18 faces the other axial side surface of the side plate portion 37 across a gap, and the other axial side surface of the second projection 26 faces the other axial side surface of the side plate portion 37 across a gap. Furthermore, the other axial side surface of the intermediate side first projection 38 faces the first side surface 25 across a gap, and one axial side surface of the intermediate side second projection 39 faces the second side surface 34 across a gap.

[0077] <Operation of rotation limiting device 4> The operation of the rotation limiting device 4 of this example will be described with reference to Figures 4(A) to 5(C). Figures 4(A) to 5(C) are diagrams that schematically show the first protrusion 18 of the first member 14, the second protrusion 26 of the second member 15, and the intermediate member 16 as viewed from the radial outside. In the following description, "one circumferential side" refers to the counterclockwise front side as viewed from the driver seated in the driver's seat, and refers to the lower side in Figures 4(A) to 5(C), and "the other circumferential side" refers to the clockwise front side as viewed from the driver seated in the driver's seat, and refers to the upper side in Figures 4(A) to 5(C).

[0078] First, when the steering wheel 2 is operated from its maximum left position (counterclockwise as seen by the driver sitting in the driver's seat) to its maximum right position (clockwise as seen by the driver sitting in the driver's seat), the rotation limiting device 4 operates in the order shown in Figure 4(A) → Figure 4(B) → Figure 4(C).

[0079] That is, when the steering wheel 2 is turned to the maximum left, as shown in Figure 4(A), one circumferential side of the first protrusion 18 abuts against the other circumferential side of the intermediate first protrusion 38, and the other circumferential side of the second protrusion 26 abuts against one circumferential side of the intermediate second protrusion 39.

[0080] From this state, when the steering wheel 2 is turned to the right and the steering shaft 9 is rotated clockwise, as shown by the arrow in Fig. 4(A), only the first member 14 rotates clockwise (towards the other circumferential side) while the other circumferential side of the second protrusion 26 remains in contact with one circumferential side of the intermediate-side second protrusion 39. Then, when the first member 14 rotates an angle smaller than 360 degrees by the sum of the circumferential width of the first protrusion 18 and the circumferential width of the intermediate-side first protrusion 38, that is, 270 degrees in this example, the other circumferential side of the first protrusion 18 comes into contact with one circumferential side of the intermediate-side first protrusion 38, as shown in Fig. 4(B). In this state, the steering wheel 2 is positioned at the center, and the pair of steered wheels 5 are facing straight ahead.

[0081] When the steering wheel 2 is further turned to the right from the state shown in FIG. 4(B), the other circumferential side surface of the first protrusion 18 presses one circumferential side surface of the middle-side first protrusion 38 toward the other circumferential side, as shown by the arrow in FIG. 4(B). As a result, the first member 14 and the intermediate member 16 rotate together in the clockwise direction (toward the other circumferential side). When the first member 14 and the intermediate member 16 rotate clockwise by an angle smaller than 360 degrees by the sum of the circumferential width of the second protrusion 26 and the circumferential width of the middle-side second protrusion 39, that is, 270 degrees in this example, the other circumferential side surface of the middle-side second protrusion 39 abuts against one circumferential side surface of the second protrusion 26, as shown in FIG. 4(C). When the other circumferential side surface of the middle-side second protrusion 39 abuts against one circumferential side surface of the second protrusion 26, the intermediate member 16 is prevented from rotating further clockwise relative to the second member 15. When the clockwise rotation of the intermediate member 16 is prevented, the first member 14 is prevented from rotating further in the clockwise direction.

[0082] Alternatively, when the steering wheel 2 is turned right from the state shown in FIG. 4(A), the first member 14 rotates clockwise. Due to the frictional force acting between the outer peripheral surface of the first cylindrical portion 19 and the inner peripheral surface of the intermediate cylindrical portion 40, the intermediate member 16 is rotated together with the first member 14, and the first member 14 and the intermediate member 16 rotate together. Then, the other circumferential side surface of the intermediate-side second protrusion 39 abuts against one circumferential side surface of the second protrusion 26, preventing the intermediate member 16 from rotating further clockwise relative to the second member 15. When the steering wheel 2 is turned further right from this state, only the first member 14 rotates clockwise. Then, the other circumferential side surface of the first protrusion 18 abuts against one circumferential side surface of the intermediate-side first protrusion 38, preventing the first member 14 from rotating further clockwise relative to the intermediate member 16.

[0083] In either case, when the first member 14 is prevented from rotating further in the clockwise direction, the steering shaft 9 and the steering wheel 2 supported and fixed to the steering shaft 9 are prevented from rotating further in the clockwise direction.

[0084] Next, when the steering wheel 2 is operated from the maximum right position to the maximum left position, the rotation limiting device 4 operates in the order shown in Figure 5(A) → Figure 5(B) → Figure 5(C).

[0085] That is, when the steering wheel 2 is turned to the maximum extent to the right, as shown in Figure 5(A), the other circumferential side of the first protrusion 18 abuts against one circumferential side of the intermediate first protrusion 38, and one circumferential side of the second protrusion 26 abuts against the other circumferential side of the intermediate second protrusion 39.

[0086] From this state, when the steering wheel 2 is turned to the left and the steering shaft 9 is rotated counterclockwise, as shown by the arrow in Fig. 5(A), only the first member 14 rotates counterclockwise (toward one circumferential side) while one circumferential side of the second protrusion 26 remains in contact with the other circumferential side of the intermediate-side second protrusion 39. Then, when the first member 14 rotates an angle smaller than 360 degrees by the sum of the circumferential width of the first protrusion 18 and the circumferential width of the intermediate-side first protrusion 38, that is, 270 degrees in this example, one circumferential side of the first protrusion 18 comes into contact with the other circumferential side of the intermediate-side first protrusion 38, as shown in Fig. 5(B). In this state, the steering wheel 2 is centered and the pair of steered wheels 5 are oriented in a straight-ahead direction.

[0087] When the steering wheel 2 is further turned to the left from the state shown in FIG. 5(B), one circumferential side surface of the first protrusion 18 presses the other circumferential side surface of the intermediate-side first protrusion 38 toward one circumferential side, as shown by the arrow in FIG. 5(B). As a result, the first member 14 and the intermediate member 16 rotate together counterclockwise (toward one circumferential side). When the first member 14 and the intermediate member 16 rotate counterclockwise by an angle smaller than 360 degrees by the sum of the circumferential width of the second protrusion 26 and the circumferential width of the intermediate-side second protrusion 39, that is, 270 degrees in this example, as shown in FIG. 5(C). When one circumferential side surface of the intermediate-side second projection 39 abuts against the other circumferential side surface of the second projection 26, the intermediate member 16 is prevented from rotating further counterclockwise relative to the second member 15. When the counterclockwise rotation of the intermediate member 16 is prevented, the first member 14 is prevented from rotating further counterclockwise.

[0088] Alternatively, when the steering wheel 2 is operated to the left from the state shown in FIG. 5(A), the first member 14 rotates counterclockwise, and the intermediate member 16 is rotated along with the first member 14 based on the frictional force acting between the outer peripheral surface of the first cylindrical portion 19 and the inner peripheral surface of the intermediate cylindrical portion 40, and the first member 14 and the intermediate member 16 rotate together. Then, one circumferential side surface of the intermediate-side second protrusion 39 abuts against the other circumferential side surface of the second protrusion 26, preventing the intermediate member 16 from rotating further counterclockwise relative to the second member 15. When the steering wheel 2 is operated further to the left from this state, only the first member 14 rotates counterclockwise. Then, one circumferential side surface of the first protrusion 18 abuts against the other circumferential side surface of the intermediate-side first protrusion 38, and the first member 14 is prevented from further counterclockwise rotation relative to the intermediate member 16.

[0089] In either case, when the first member 14 is prevented from rotating further counterclockwise, the steering shaft 9 and the steering wheel 2 supported and fixed to the steering shaft 9 are prevented from rotating further counterclockwise.

[0090] In the rotation limiting device 4 of this example, the rotation support mechanism 17 supports the second member 15 around the first member 14 to allow relative rotation with respect to the first member 14 and to prevent inadvertent separation. Specifically, the intermediate cylindrical portion 40 of the intermediate member 16 is externally fitted onto the large-diameter cylindrical surface portion 21 of the first member 14 without rattle to allow relative rotation, and the second member 15 is arranged around the first member 14 and the intermediate member 16. The rotation support mechanism 17 is then disposed between the small-diameter cylindrical surface portion 22 of the first member 14 and the inner circumferential surface of the small-diameter cylindrical portion 30 of the second member 15. Therefore, the rotation limiting device 4 can be pre-assembled and assembled even before the first member 14 is coupled and fixed to the steering shaft 9 and the second member 15 is supported and fixed to the steering column 8. This facilitates parts management and the assembly of the rotation limiting device 4 to the steering unit 3, improving the handleability of the rotation limiting device 4. On the other hand, the inventions described in the above-mentioned Patent Documents 1 to 5 do not have a mechanism such as the rotation support mechanism 17 in the present disclosure that supports the second member 15 so that it can rotate relatively around the first member 14 and so that it does not come apart accidentally, making parts management and assembly work cumbersome.

[0091] As described above, in the rotation limiting device 4 of this example, the intermediate member 16 has a first intermediate protrusion 38 that protrudes from the other axial side surface of the side plate portion 37 toward the other axial side, and a second intermediate protrusion 39 that protrudes from one axial side surface of the side plate portion 37 toward one axial side.

[0092] In contrast to this, Patent Document 2 discloses that the idle rotors 14 to 16 have engagement pieces 14a to 16a, 14b to 16b, but the multi-rotation limit mechanism of Patent Document 2 is a device for detecting the rotation end of the rotating shaft, and does not lock the rotation of the rotating shaft, and is different in configuration and function from the intermediate side first protrusion 38 and intermediate side second protrusion 39 of the present disclosure.

[0093] Patent Document 3 discloses a first engagement member 141 that is formed integrally with the intermediate engagement member 150 and extends in the axial direction, but the first engagement member 141 prevents the generation of impact sounds by coming into contact with the first and second arms 161, 162 of the biasing member 160, and its function is different from that of the intermediate side first protrusion 38 and the intermediate side second protrusion 39 disclosed herein.

[0094] Patent document 4 discloses that a first abutment portion 412 is provided that protrudes from the integrally rotating portion 410 on only one axial side, but does not disclose a member that protrudes from the integrally rotating portion 410 on the other axial side.

[0095] FIG. 8 of Patent Document 5 discloses an outer peripheral support portion 175 formed to protrude on both axial sides of the second rotating member 170. However, the outer peripheral support portion 175 protrudes radially outward from the outer peripheral side of the second rotating member 170. That is, the outer peripheral support portion 175 is not located radially inward from the outer peripheral surface of the second rotating member 170, which is disadvantageous in terms of compactness and strength. In other words, repeated contact of the outer peripheral support portion 175 with the first support portion 161 of the first rotating member 160 or the inner peripheral support portion 189 of the housing 180 may cause the outer peripheral support portion 175 to deform or rotate as viewed radially. In contrast, in the presently disclosed invention, the intermediate-side first protrusion 38 and the intermediate-side second protrusion 39 are formed integrally with the side plate portion 37 and do not protrude radially outward beyond the side plate portion 37, making the above-described problem less likely to occur. It should be noted that the third support portion 173 of the second rotating member 170 shown in Figure 3 of Patent Document 5 protrudes only on one axial side, and is therefore different from the intermediate side first protrusion 38 and intermediate side second protrusion 39 of the present disclosure, which protrude on both axial sides.

[0096] Furthermore, the rotation limiting device 4 of this example can adjust the amount of rotation of the steering shaft 9 that is fixedly coupled to the first member 14 by changing the number of intermediate members 16 that are arranged between the first protrusion 18 and the second protrusion 26 in the axial direction. Therefore, the rotation limiting device 4 of this example can improve the degree of freedom in setting the amount of rotation of the steering shaft 9. Specifically, the more intermediate members 16 are used, the greater the amount of rotation of the steering shaft 9 can be.

[0097] 6 to 8(D) show a rotation limiting device 4a including two intermediate members 16a, 16b. The intermediate members 16a, 16b each include a hollow, circular, plate-like side plate 37a, 37b, a first intermediate protrusion 38a, 38b protruding toward the other axial direction from a single circumferential position on the other axial side surface of the side plate 37a, 37b, and a second intermediate protrusion 39a, 39b protruding toward one axial direction from a single position on one axial side surface that is radially opposite the first intermediate protrusion 38a, 38b. That is, the intermediate members 16a, 16b do not include the intermediate cylindrical portion 40 included in the intermediate member 16 according to the first embodiment. The two intermediate members 16a, 16b are arranged in series in the axial direction and fitted onto the first cylindrical portion 19 of the first member 14 so as to be rotatable relative to each other. The intermediate member 16a on the other axial side and the intermediate member 16b on one axial side are given different reference numerals for ease of explanation, but have the same shape. The axial length of the large-diameter cylindrical surface portion 21 of the first cylindrical portion 19 and the axial length of the large-diameter cylindrical portion 29 of the second cylindrical portion 27 are longer than those of the structure according to the first example embodiment by the amount of the additional intermediate member 16a, 16b.

[0098] The rotation limiting device 4a of this modified example has three annular gap adjustment members 48. Of the three gap adjustment members 48, the gap adjustment member 48 on the other axial side is sandwiched in the axial direction between a radially inner portion of the other axial side surface of the side plate portion 37a of the intermediate member 16a on the other axial side and a radially inner portion of one axial side surface (first side surface 25) of the first flange portion 20 of the first member 14. The middle gap adjustment member 48 is sandwiched in the axial direction between a radially inner portion of one axial side surface of the side plate portion 37a of the intermediate member 16a on the other axial side and a radially inner portion of the other axial side surface of the side plate portion 37b of the intermediate member 16b on the other axial side. The gap adjustment member 48 on one axial side is also sandwiched in the axial direction between a radially inner portion of one axial side surface of the side plate portion 37b of the intermediate member 16b on the other axial side and a radially inner portion of the other axial side surface (second side surface 34) of the second flange portion 28 of the second member 15.

[0099] In this modification, each gap adjustment member 48 is formed of a spacer made of a material having a small coefficient of friction with one axial side surface of the first flange portion 20 and the other axial side surface of the second flange portion 28, and / or with respect to the side plate portions 37 a, 37 b. Specifically, each gap adjustment member 48 can be formed of a resin washer, oil-impregnated metal, or the like, for example.

[0100] In a steering unit 3 (see Figure 1) equipped with the rotation limiting device 4a of this modified example, when the steering wheel 2 is operated from the maximum left position to the maximum right position, the rotation limiting device 4a operates in the order shown in Figure 7(A) → Figure 7(B) → Figure 7(C) → Figure 7(D).

[0101] When the steering wheel 2 is turned to the maximum left, as shown in FIG. 7(A), one circumferential side surface of the first protrusion 18 abuts against the other circumferential side surface of the intermediate-side first protrusion 38a of the intermediate member 16a on the other axial side, one circumferential side surface of the intermediate-side second protrusion 39a of the intermediate member 16a on the other axial side abuts against the other circumferential side surface of the intermediate-side first protrusion 38b of the intermediate member 16b on one axial side, and one circumferential side surface of the intermediate-side second protrusion 39b of the intermediate member 16b on one axial side abuts against the other circumferential side surface of the second protrusion 26.

[0102] From this state, when the steering wheel 2 is turned to the right and the steering shaft 9 is rotated clockwise, as shown by the arrow in Figure 7(A), one circumferential side surface of the intermediate-side second protrusion 39a of the intermediate member 16a on the other axial side abuts against the other circumferential side surface of the intermediate-side first protrusion 38b of the intermediate member 16b on one axial side, and one circumferential side surface of the intermediate-side second protrusion 39b of the intermediate member 16b on one axial side remains in contact with the other circumferential side surface of the second protrusion 26, and only the first member 14 rotates clockwise (towards the other circumferential side). Then, when the first member 14 rotates clockwise by an angle that is smaller than 360 degrees by the sum of the circumferential width of the first protrusion 18 and the circumferential width of the intermediate side first protrusion 38a, as shown in Figure 7(B), the other circumferential side surface of the first protrusion 18 abuts against one circumferential side surface of the intermediate side first protrusion 38a of the intermediate member 16a on the other axial side.

[0103] 7(B), when the steering wheel 2 is further turned to the right, one circumferential side surface of the intermediate-side first protrusion 38a of the intermediate member 16a on the other axial side is pushed toward the other circumferential side by the other circumferential side surface of the first protrusion 18, as shown by the arrow in FIG. 7(B). As a result, one circumferential side surface of the intermediate-side second protrusion 39b of the intermediate member 16b on one axial side remains in contact with the other circumferential side surface of the second protrusion 26, and the first member 14 and the intermediate member 16a on the other axial side rotate clockwise (toward the other circumferential side) together. Then, when the first member 14 and the intermediate member 16a on the other axial side rotate clockwise by an angle that is smaller than 360 degrees by the sum of the circumferential width of the intermediate-side second protrusion 39a of the intermediate member 16a on the other axial side and the circumferential width of the intermediate-side first protrusion 38b of the intermediate member 16b on one axial side, as shown in Figure 7(C) , the other circumferential side surface of the intermediate-side second protrusion 39a of the intermediate member 16a on the other axial side abuts against one circumferential side surface of the intermediate-side first protrusion 38b of the intermediate member 16b on one axial side.

[0104] When the steering wheel 2 is further turned to the right from the state shown in Fig. 7(C), the first member 14 and the intermediate member 16a on the other axial side rotate clockwise together, and as shown by the arrow in Fig. 7(C), one circumferential side surface of the intermediate-side first protrusion 38b of the intermediate member 16b on one axial side is pushed toward the other circumferential side by the other circumferential side surface of the intermediate-side second protrusion 39a of the intermediate member 16a on the other axial side. As a result, the first member 14 and the two intermediate members 16a, 16b rotate clockwise (toward the other circumferential side) together. When the first member 14 and the two intermediate members 16a, 16b rotate clockwise by an angle smaller than 360 degrees by the sum of the circumferential width of the intermediate-side second protrusion 39b of the intermediate member 16b on one axial side and the circumferential width of the second protrusion 26, as shown in FIG. 7(D), the other circumferential side surface of the intermediate-side second protrusion 39b of the intermediate member 16b on one axial side abuts against one circumferential side surface of the second protrusion 26. As a result, the intermediate member 16b on one axial side is prevented from rotating in the clockwise direction further relative to the second member 15. When the clockwise rotation of the intermediate member 16b on one axial side is prevented, the intermediate member 16a on the other axial side is prevented from rotating in the clockwise direction further. When the clockwise rotation of the intermediate member 16a on the other axial side is prevented, the first member 14 is prevented from rotating in the clockwise direction further, and the steering shaft 9 and the steering wheel 2 supported and fixed to the steering shaft 9 are prevented from rotating in the clockwise direction further.

[0105] In contrast, when the steering wheel 2 is turned from the maximum right position to the maximum left position, the rotation limiting device 4a operates in the order shown in Figure 8(A) → Figure 8(B) → Figure 8(C) → Figure 8(D).

[0106] That is, when the steering wheel 2 is turned to the maximum right, as shown in FIG. 8(A), the other circumferential side surface of the first protrusion 18 abuts against one circumferential side surface of the intermediate-side first protrusion 38a of the intermediate member 16a on the other axial side, the other circumferential side surface of the intermediate-side second protrusion 39a of the intermediate member 16a on the other axial side abuts against one circumferential side surface of the intermediate-side first protrusion 38b of the intermediate member 16b on one axial side, and the other circumferential side surface of the intermediate-side second protrusion 39b of the intermediate member 16b on one axial side abuts against one circumferential side surface of the second protrusion 26.

[0107] From this state, when the steering wheel 2 is turned to the left and the steering shaft 9 is rotated counterclockwise, as shown by the arrow in Figure 8 (A), the other circumferential side surface of the intermediate-side second protrusion 39a of the intermediate member 16a on the other axial side abuts against one circumferential side surface of the intermediate-side first protrusion 38b of the intermediate member 16b on one axial side, and the other circumferential side surface of the intermediate-side second protrusion 39b of the intermediate member 16b on one axial side remains in contact with one circumferential side surface of the second protrusion 26, and only the first member 14 rotates counterclockwise (towards one circumferential side). Then, when the first member 14 rotates counterclockwise by an angle that is smaller than 360 degrees by the sum of the circumferential width of the first protrusion 18 and the circumferential width of the intermediate side first protrusion 38a, one circumferential side surface of the first protrusion 18 abuts against the other circumferential side surface of the intermediate side first protrusion 38a of the intermediate member 16a on the other axial side, as shown in Figure 8(B).

[0108] 8(B), when the steering wheel 2 is further turned to the left, the other circumferential side surface of the intermediate-side first protrusion 38a of the intermediate member 16a on the other axial side is pushed toward one circumferential side by one circumferential side surface of the first protrusion 18, as shown by the arrow in FIG. 8(B). As a result, the first member 14 and the intermediate member 16a on the other axial side rotate counterclockwise (to one circumferential side) integrally, with the other circumferential side surface of the intermediate-side second protrusion 39b of the intermediate member 16b on one axial side remaining in contact with one circumferential side surface of the second protrusion 26. Then, when the first member 14 and the intermediate member 16a on the other axial side rotate counterclockwise by an angle that is smaller than 360 degrees by the sum of the circumferential width of the intermediate-side second protrusion 39a of the intermediate member 16a on the other axial side and the circumferential width of the intermediate-side first protrusion 38b of the intermediate member 16b on one axial side, one circumferential side surface of the intermediate-side second protrusion 39a of the intermediate member 16a on the other axial side comes into contact with the other circumferential side surface of the intermediate-side first protrusion 38b of the intermediate member 16b on one axial side, as shown in Figure 8(C).

[0109] When the steering wheel 2 is further turned to the left from the state shown in Fig. 8(C), the first member 14 and the intermediate member 16a on the other axial side rotate counterclockwise together, and as shown by the arrow in Fig. 8(C), one circumferential side surface of the intermediate-side second protrusion 39a of the intermediate member 16a on the other axial side presses the other circumferential side surface of the intermediate-side first protrusion 38b of the intermediate member 16b on one axial side toward one circumferential side, thereby causing the first member 14 and the two intermediate members 16a, 16b to rotate counterclockwise (to one circumferential side) together. Then, when the first member 14 and the two intermediate members 16a, 16b rotate counterclockwise by an angle that is smaller than 360 degrees by the sum of the circumferential width of the intermediate-side second protrusion 39b of the intermediate member 16b on one axial side and the circumferential width of the second protrusion 26, one circumferential side surface of the intermediate-side second protrusion 39b of the intermediate member 16b on one axial side comes into contact with the other circumferential side surface of the second protrusion 26, as shown in FIG. 8(D). As a result, the intermediate member 16b on one axial side is prevented from rotating counterclockwise any further relative to the second member 15. When the counterclockwise rotation of the intermediate member 16b on one axial side is prevented, the intermediate member 16a on the other axial side is prevented from rotating counterclockwise any further. When the counterclockwise rotation of the intermediate member 16a on the other axial side is prevented, the first member 14 is prevented from rotating further counterclockwise, and the steering shaft 9 and the steering wheel 2 supported and fixed to the steering shaft 9 are prevented from rotating further counterclockwise.

[0110] In this modified example, too, based on the frictional force acting between the outer peripheral surface of the first cylindrical portion 19 of the first member 14 and the inner peripheral surface of the side plate portion 37a of the intermediate member 16a on the other axial side and / or the inner peripheral surface of the side plate portion 37b of the intermediate member 16b on one axial side, the intermediate member 16a on one axial side and / or the intermediate member 16b on the other axial side may rotate so as to be rotated by the first member 14. In this case, the operating sequence of the rotation limiting device 4a may differ from the example shown in FIGS. 7 and 8.

[0111] As described above, the rotation limiting device 4 (4a) of this example can increase the amount of rotation of the steering shaft 9 by increasing the number of intermediate members 16 (16a, 16b) each having an intermediate first protrusion 38 (38a, 38b) protruding toward the other axial side and an intermediate second protrusion 39 (39a, 39b) protruding toward one axial side, and arranging the intermediate members 16 (16a, 16b) in series in the axial direction. Specifically, assuming that the circumferential width W of the first protrusion 18, the second protrusion 26, the intermediate first protrusion 38 (38a, 38b), and the intermediate second protrusion 39 (39a, 39b) are all the same, each additional intermediate member 16 can increase the amount of rotation of the steering shaft 9 by an angle that is smaller than 360 degrees by twice the circumferential width W (2W).

[0112] When the circumferential width W is 45 degrees, the amount of rotation of the steering shaft 9 can be increased by 270 degrees for each additional intermediate member 16 (16a, 16b), and the number of lock-to-lock rotations of the steering wheel 2 can be increased by 0.75. For example, in a rotation limiting device 4 that includes only one intermediate member 16 as in the first example of the embodiment, the amount of rotation of the steering shaft 9 is 540 degrees (the number of lock-to-lock rotations of the steering wheel 2 is 1.5), but in a rotation limiting device 4a that includes two intermediate members 16a, 16b as in the modified example, the amount of rotation of the steering shaft 9 can be increased to 810 degrees (the number of lock-to-lock rotations of the steering wheel 2 is 2.25).

[0113] The rotation limiting device 4a of this modified example has gap adjustment members 48 respectively in the portion between the first member 14 and the intermediate member 16a on one axial side, the portion between the intermediate member 16a on one axial side and the intermediate member 16b on the other axial side, and the portion between the intermediate member 16b on the other axial side and the second member 15. Therefore, while suppressing axial rattle of the intermediate members 16a, 16b relative to the first member 14 and the second member 15, it is possible to prevent the rotational resistance between the first member 14 and the intermediate member 16a on the other axial side, the rotational resistance between the intermediate member 16a on the other axial side and the intermediate member 16b on one axial side, and the rotational resistance between the intermediate member 16b on one axial side and the second member 15 from becoming unnecessarily large.

[0114] However, some or all of the gap adjustment members may be preload-applying members that exert axial elasticity. The preload-applying members may be, for example, a disc spring disposed between a pair of resin washers. When a preload-applying member is disposed between the second flange portion and the side plate portion, the preload-applying member may be a disc spring disposed between a metal washer on one axial side and a resin washer on the other axial side. This provides the function of applying preload between the first and second members while preventing unnecessary increase in rotational resistance between the first and second members and the intermediate member.

[0115] Furthermore, in the rotation limiting device 4a of this modified example, the two intermediate members 16a, 16b have the same shape. That is, in the rotation limiting device of the present disclosure, the amount of rotation of the rotatable member can be adjusted by increasing or decreasing the number of intermediate members having the same shape. Therefore, the rotation limiting device of the present disclosure can prevent unnecessary increases in the manufacturing costs, management costs, and assembly costs of parts, and can suppress increases in the manufacturing costs of the rotation limiting device.

[0116] According to the rotation limiting device 4 of this example, the axial connection strength of the first member 14 to the steering shaft 9 and the axial connection strength of the second member 15 to the steering column 8 do not need to be increased unnecessarily.

[0117] That is, in the stopper unit 100 having the conventional structure of Patent Document 1 shown in FIG. 14 described above, both circumferential side surfaces of the first rotation protrusion 104, both circumferential side surfaces of the fixed protrusion 105, and both circumferential side surfaces of the second rotation protrusion 107 are inclined with respect to the axial direction when viewed from the radial outside. Therefore, when the first rotation member 101 rotates, a force is applied between the first rotation member 101 and the second rotation member 103 and / or between the second rotation member 103 and the housing 102 in a direction that moves them away from each other in the axial direction. Therefore, it is necessary to sufficiently increase the axial connection strength of the first rotation member 101 to the steering shaft and the axial connection strength of the housing 102 to the vehicle body.

[0118] In contrast, in the rotation limiting device 4 of this example, the circumferentially opposite side surfaces of the first protrusion 18, the circumferentially opposite side surfaces of the second protrusion 26, the circumferentially opposite side surfaces of the intermediate-side first protrusion 38, and the circumferentially opposite side surfaces of the intermediate-side second protrusion 39 each extend linearly in the axial direction when viewed from the radial direction. Therefore, even when the first member 14 rotates in conjunction with the rotation of the steering shaft 9, no axial force acts between the first member 14 and the intermediate member 16, or between the intermediate member 16 and the second member 15. Therefore, there is no need to unnecessarily increase the axial connection strength of the first member 14 to the steering shaft 9 and the axial connection strength of the second member 15 to the steering column 8, and therefore it is possible to prevent an unnecessarily high manufacturing cost for the steering device 1 including the rotation limiting device 4.

[0119] In the rotation limiting device 4 of this example, the radial rolling bearing 41 of the rotation support mechanism 17 is configured as a ball bearing that uses balls as the multiple rolling elements 45. However, when implementing the present disclosure, the radial rolling bearing can also be configured as a radial roller bearing that uses rollers as the rolling elements or a radial needle bearing that uses needles.

[0120] In addition, in this example, the inner ring 43 of the radial rolling bearing 41 is prevented from displacing to one side in the axial direction by a retaining ring 42a that is engaged with an inner diameter side retaining groove 24 provided in the small diameter cylindrical surface portion 22 of the first member 14. That is, the inner ring 43 is positioned in the axial direction by being sandwiched between the inner diameter side stepped surface 23 provided on the outer circumferential surface of the first member 14 and the retaining ring 42a. However, when implementing the present disclosure, the inner ring of the radial rolling bearing can also be externally fitted onto the first member by press fitting to prevent displacing to one side in the axial direction.

[0121] The outer ring 44 of the radial rolling bearing 41 is prevented from displacing to one side in the axial direction by a retaining ring 42b that is engaged with an outer diameter side retaining groove 33 provided on the inner peripheral surface of the small diameter cylindrical portion 30 of the second member 15. In other words, the outer ring 44 is positioned in the axial direction by being sandwiched between the outer diameter side stepped surface 32 provided on the inner peripheral surface of the second member 15 and the retaining ring 42b. However, when implementing the present disclosure, it is also possible to prevent the outer ring of the radial rolling bearing from displacing to one side in the axial direction by press-fitting it into the second member.

[0122] Alternatively, the rotation support mechanism can be configured to include a radial plain bearing (bush) instead of a radial rolling bearing. In this case, the radially inner portion of the radial plain bearing is clamped in the axial direction between an inner diameter side stepped surface provided on the outer peripheral surface of the first member and a retaining ring engaged with the outer peripheral surface, and the radially outer portion of the radial plain bearing is clamped in the axial direction between an outer diameter side stepped surface provided on the inner peripheral surface of the second member and a retaining ring engaged with the inner peripheral surface.

[0123] In this example, the circumferential widths of the first protrusions 18, the second protrusions 26, the intermediate-side first protrusions 38, and the intermediate-side second protrusions 39 are all 45 degrees. However, when implementing the present disclosure, the circumferential widths of the first protrusions, the second protrusions, the intermediate-side first protrusions, and the intermediate-side second protrusions are not particularly limited and can be set to any desired values. However, if these circumferential widths are excessively small, the strength of the protrusions cannot be sufficiently ensured. On the other hand, if these circumferential widths are excessively large, the amount of rotation of the rotating member becomes unnecessarily small. Taking these factors into consideration, the circumferential widths of the first protrusions, the second protrusions, the intermediate-side first protrusions, and the intermediate-side second protrusions can each be 90 degrees or less, and preferably between 30 degrees and 60 degrees.

[0124] If the circumferential width of the first projection, the circumferential width of the second projection, the circumferential width of the intermediate first projection, and the circumferential width of the intermediate second projection are all W [deg], and the number of intermediate members is n, then the amount of rotation α [deg] of the rotating member coupled and fixed to the first member 14 is α = (360 - 2W)(n + 1). Therefore, if W is set to 90 degrees or less, preferably between 30 and 60 degrees, the lock-to-lock rotation speed of the steering wheel set in a typical automobile (approximately 1 to 4.167) can be achieved with a minimum number of intermediate members (four or less).

[0125] Furthermore, when implementing the present disclosure, the circumferential width of the first protrusion, the circumferential width of the second protrusion, the circumferential width of the intermediate first protrusion, and the circumferential width of the intermediate second protrusion do not all need to be the same, and some or all of them can be different.

[0126] In this example, the phases of the first intermediate protrusion 38 and the second intermediate protrusion 39 provided on the intermediate member 16 in the circumferential direction are made to differ by 180 degrees. This allows the center of gravity of the intermediate member 16 to be positioned on the central axis O of the intermediate member 16. This prevents the intermediate member 16 from rotating due to the action of gravity even when no torque is applied to the steering shaft 9. However, when implementing the present disclosure, the phases of the first intermediate protrusion and the second intermediate protrusion in the circumferential direction can be set arbitrarily. Specifically, for example, as shown in a fourth example of an embodiment shown in FIGS. 12 and 13 (described later), the phases of the first intermediate protrusion and the second intermediate protrusion in the circumferential direction can be made to coincide with each other, or the phases of the first intermediate protrusion and the second intermediate protrusion in the circumferential direction can be made to differ by 90 degrees.

[0127] In this example, the first protrusion 18, the second protrusion 26, the intermediate first protrusion 38, and the intermediate second protrusion 39 all have a fan-shaped end face shape when viewed in the axial direction. This increases the contact area between the first protrusion 18 and the intermediate first protrusion 38, and the contact area between the second protrusion 26 and the intermediate second protrusion 39, thereby reducing the contact surface pressure. In contrast, Patent Document 2 neither describes nor suggests the specific shapes of the engagement pieces 13a to 16a, 14b to 17b.

[0128] In this example, the first member 14 is connected and fixed to the steering shaft 9, which rotates when in use, and the second member 15 is connected and fixed to the steering column 8, which does not rotate when in use. However, when implementing this disclosure, it is also possible to connect and fix the second member to a rotating member that rotates when in use, and the first member to a fixed member that does not rotate when in use.

[0129] When implementing the present disclosure, the materials constituting the first member, the second member, and the intermediate member are not particularly limited as long as they are capable of relative rotation (sliding) with respect to one another, and can be made of, for example, synthetic resin or metal material. Furthermore, the first member, the second member, and the intermediate member can be integrally formed as a whole, or can be formed by combining multiple components. When combining multiple components, for example, the protrusions and the portions other than the protrusions can be made of different materials. If the first protrusions and the intermediate-side first protrusions are made of different metal materials, adhesion between the first protrusions and the intermediate-side first protrusions can be prevented, and if the second protrusions and the intermediate-side second protrusions are made of different metal materials, adhesion between the second protrusions and the intermediate-side second protrusions can be prevented. Furthermore, if the protrusions are made of synthetic resin, impact noise can be reduced.

[0130] To prevent adhesion and seizure between the first member, the second member, and the intermediate member, it is desirable to fill the cylindrical space between the outer peripheral surface of the first cylindrical portion of the first member and the inner peripheral surface of the second cylindrical portion of the second member with a lubricant such as grease. In this case, an oil seal may be provided between the first cylindrical portion of the first member and the second flange portion and / or the second cylindrical portion of the second member.

[0131] Furthermore, in this example, an example has been described in which the rotation limiting device 4 is incorporated into the steering unit 3 that constitutes the steer-by-wire steering device 1, but the rotation limiting device of the present disclosure is not limited to steer-by-wire steering devices, and can be incorporated and used to limit the amount of rotation of the rotating member of any rotating mechanical device, including a steering device in which a steering unit and a turning unit are mechanically connected.

[0132] [Second Example of Implementation] 9 illustrates a second embodiment of the present disclosure. In a rotation limiting device 4b of this embodiment, similar to the modified example of the first embodiment, an intermediate member 16c includes a hollow circular plate-shaped side plate 37c, a first intermediate protrusion 38c protruding from one circumferential position on the other axial side surface of the side plate 37c toward the other axial side, and a second intermediate protrusion 39c protruding from one axial side surface of the side plate 37c toward the one axial side from one position radially opposite the first intermediate protrusion 38c. In other words, the intermediate member 16c does not include the intermediate tubular portion 40 included in the intermediate member 16 according to the first embodiment.

[0133] The rotation limiting device 4b of this example has two annular gap adjustment members 48. Of the two gap adjustment members 48, the gap adjustment member 48 on the other axial side is sandwiched in the axial direction between a radially inner portion of one axial side surface (first side surface 25) of the first flange portion 20 of the first member 14 and a radially inner portion of the other axial side surface of the side plate portion 37c. The gap adjustment member 48 on one axial side is sandwiched in the axial direction between a radially inner portion of one axial side surface of the side plate portion 37c and a radially inner portion of the other axial side surface (second side surface 34) of the second flange portion 28 of the second member 15.

[0134] Each gap adjustment member 48 is formed of a spacer made of a material having a small coefficient of friction with respect to one axial side surface of the first flange portion 20, the other axial side surface of the second flange portion 28, and / or the side plate portion 37c. Specifically, each gap adjustment member 48 can be formed of a resin washer, oil-impregnated metal, or the like, for example.

[0135] The rotation limiting device 4b of this example can prevent unnecessary increase in rotational resistance between the intermediate member 16c and the first member 14 and the second member 15, while suppressing axial rattle of the intermediate member 16c relative to the first member 14 and the second member 15. The configuration and effects of other parts are the same as those of the first example of the embodiment and its modified example.

[0136] [Third example of embodiment] 10 and 11 show a third embodiment of the present disclosure. A rotation limiting device 4c of this embodiment includes a first member 14, a second member 15, and three intermediate members 16c. All of the intermediate members 16c have the same shape. In this embodiment, each intermediate member 16c includes a hollow, circular side plate 37c, a first intermediate protrusion 38c protruding from a single circumferential position on the other axial side surface of the side plate 37c toward the other axial side, and a second intermediate protrusion 39c protruding from a single axial side surface on the radially opposite side to the first intermediate protrusion 38c toward the one axial side. The three intermediate members 16c are aligned in series in the axial direction and fitted onto the large-diameter cylindrical surface portion 21 of the first tubular portion 19 of the first member 14 for relative rotation. In addition, the axial length of the large diameter cylindrical surface portion 21 of the first cylindrical portion 19 and the axial length of the large diameter cylindrical portion 29 of the second cylindrical portion 27 are longer than those of the structure according to the second example of the embodiment by the amount of the two additional intermediate members 16c.

[0137] Furthermore, the rotation limiting device 4c of this example is provided with four gap adjustment members 48 in the portions between the three intermediate members 16c, the portion between the intermediate member 16c on the other axial side and the first flange portion 20, and the portion between the intermediate member 16c on one axial side and the second flange portion 28. This prevents axial wobble of the three intermediate members 16c relative to the first member 14 and the second member 15. Each gap adjustment member 48 is made of a material with a low coefficient of friction with one axial side surface (first side surface 25) of the first flange portion 20 and the other axial side surface (second side surface 34) of the second flange portion 28, and / or the side plate portion 37c.

[0138] Because the rotation limiting device 4c of this example includes three intermediate members 16c, if the circumferential widths of the first protrusion, the second protrusion, the intermediate first protrusion, and the intermediate second protrusion are all 45 degrees, the amount of rotation of the steering shaft 9 (see FIG. 1 ) coupled and fixed to the first member 14 can be doubled compared to the structure including only one intermediate member 16, such as the rotation limiting device 4 of the first example embodiment. Specifically, in the rotation limiting device 4c of this example, if the circumferential widths W of the first protrusion 18, the second protrusion 26, the intermediate first protrusion 38c, and the intermediate second protrusion 39c are all 45 degrees, the amount of rotation of the steering shaft 9 can be 1080 degrees.

[0139] In the rotation limiting device 4c of this example, the three intermediate members 16c have the same shape. This prevents unnecessary increases in the manufacturing costs, management costs, and assembly costs of the parts, and suppresses increases in the manufacturing costs of the rotation limiting device 4c. The configurations, functions, and effects of the other parts are the same as those of the first example of the embodiment, its modified example, and the second example.

[0140] [Fourth Example of Embodiment] 12 and 13 show a fourth embodiment of the present disclosure. A rotation limiting device 4d of this embodiment includes a first member 14, a second member 15, and three intermediate members 16d. All of the intermediate members 16d have the same shape. In this embodiment, each intermediate member 16d includes a hollow, circular side plate 37d, a first intermediate protrusion 38d protruding toward the other axial direction from a single circumferential position on the other axial side surface of the side plate 37d, and a second intermediate protrusion 39d protruding toward one axial direction from a single position on one axial side surface that is in phase with the first intermediate protrusion 38d in the circumferential direction. The three intermediate members 16d are arranged in series in the axial direction and fitted onto the large-diameter cylindrical surface portion 21 of the first tubular portion 19 of the first member 14 so as to be rotatable relative to each other.

[0141] The rotation limiting device 4d of this example can prevent a large force from acting in the circumferential direction on the side plate portion 37d of each intermediate member 16d.

[0142] That is, for example, in a structure such as rotation limiting device 4c according to a third example embodiment in which the intermediate first protrusion 38c and the intermediate second protrusion 39c are out of phase with each other in the circumferential direction by 180 degrees, the circumferential force applied from the first protrusion 18 to the intermediate first protrusion 38c is transmitted in the circumferential direction through side plate portion 37c and applied from the intermediate second protrusion 39c to the second protrusion 26. Therefore, since a large circumferential force may be applied to side plate portion 37c, it is necessary to ensure that side plate portion 37c has sufficient strength.

[0143] In contrast, in the rotation limiting device 4d of this embodiment, the circumferential phases of the intermediate-side first protrusion 38d and the intermediate-side second protrusion 39d are aligned. Therefore, most of the circumferential force applied from the first protrusion 18 to the intermediate-side first protrusion 38d is transmitted directly to the intermediate-side second protrusion 39d without acting on the side plate portion 37d, and is then applied from the intermediate-side second protrusion 39d to the second protrusion 26. This prevents a large circumferential force from acting on the side plate portion 37d. This allows the axial thickness of the side plate portion 37d to be reduced, or the intermediate-side first protrusion 38d and the intermediate-side second protrusion 39d can be made of a metal material and the side plate portion 37d can be made of a synthetic resin, which facilitates weight reduction of the intermediate member 16d. The remaining configurations, functions, and effects are similar to those of the first embodiment, its modified example, second embodiment, and third embodiment.

[0144] This application is based on a Japanese patent application (Patent Application No. 2022-021008) filed on February 15, 2022, the contents of which are incorporated herein by reference. [Explanation of symbols]

[0145] 1 Steering device 2 steering wheels 3 Steering unit 4, 4a, 4b, 4c, 4d Rotation limiter 5 steering wheel 6. Steering unit 7. Control Unit 8. Steering column 9. Steering shaft 10. Reaction force application device 11 Gear housing 12 Steering actuator 13 Tie rod 14 First member 15 Second member 16, 16a, 16b, 16c, 16d Intermediate members 17 Rotation support mechanism 18 1st projection 19 First cylinder part 20 First flange 21 Large diameter cylindrical surface 22 Small diameter cylindrical surface part 23 Inner diameter step surface 24 Inner diameter locking groove 25 First aspect 26 2nd protrusion 27 Second tube part 28 Second flange 29 Large diameter cylinder 30 Small diameter cylinder part 31 Connection plate 32 Outer diameter step surface 33 Outer diameter locking groove 34 Second aspect 35 Ears 36 Binding hole 37, 37a, 37b, 37c, 37d Side plate part 38, 38a, 38b, 38c, 38d 1st protrusion on intermediate side 39, 39a, 39b, 39c, 39d 2nd protrusion on middle side 40 Intermediate cylinder part 41 Radial rolling bearing 42a, 42b retaining ring 43 Inner Circle 44 outer ring 45 rolling elements 46 Inner raceway 47 Outer raceway 48 Gap adjustment member 100 Stopper unit 101 first rotating member 102 Housing 103 Second rotating member 104 First rotating protrusion 105 Fixed protrusion 106 Cylindrical part 107 Second rotating protrusion

Claims

1. a first member having a first projection; a second member having a second protrusion disposed on one axial side of the first protrusion, the second member being disposed around the first member so as to be rotatable relative to the first member; at least one intermediate member having a side plate portion disposed between the first projection and the second projection in the axial direction, a first intermediate projection protruding from the other axial side surface of the side plate portion toward the other axial side, and a second intermediate projection protruding from one axial side surface of the side plate portion toward one axial side, the intermediate member being disposed between the first member and the second member in the radial direction and supported so as to be rotatable relative to the first member and the second member; a rotation support mechanism that supports the second member around the first member so as to be rotatable relative to the first member, the first member has a first side surface facing one side in the axial direction, and the first protrusion protruding from the first side surface toward one side in the axial direction, the second member has a second side surface facing the other axial side, and the second protrusion protruding from the second side surface toward the other axial side, the first member has a first cylindrical portion into which the at least one intermediate member is externally fitted so as to be relatively rotatable, and a first flange portion protruding radially outward from an outer circumferential surface of the first cylindrical portion, the first flange portion has the first side surface on one side surface in the axial direction, the first cylindrical portion extends from a radially inner end of the first flange portion to one side in the axial direction, the rotation support mechanism is disposed on an outer peripheral surface of the first cylindrical portion and cantilevers one axial side of the first cylindrical portion relative to the second member; Rotation limiter.

2. the second member has a second cylindrical portion and a second flange portion protruding radially inward from an inner circumferential surface of the second cylindrical portion, The second flange portion has the second side surface on the other side surface in the axial direction. The rotation limiting device of claim 1 .

3. the rotation support mechanism includes a radial rolling bearing having an inner ring fitted onto the outside of the first member, an outer ring fitted onto the inside of the second member, and a plurality of rolling elements arranged to roll freely between the inner ring and the outer ring. The rotation limiting device of claim 1 .

4. a steering shaft; and a rotation limiting device that limits the amount of rotation of the steering shaft to a predetermined value; The rotation limiting device is configured by the rotation limiting device according to any one of claims 1 to 3, One of the first member and the second member is coupled and fixed to the steering shaft, and the other of the first member and the second member is supported and fixed to a portion that does not rotate even during use. Steering device.

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