Rotation limiter and steering device

Abstract

A rotation limiting device comprises: a first member having a first projection; a second member having a second projection arranged further to one side in the axial direction than the first projection and located on the circumference of the first member so that it can rotate relative to the first member; a side plate part arranged between the first projection and the second projection in the axial direction;at least one intermediate member, comprising a first intermediate projection extending from a side surface of the side plate part opposite in the axial direction to a side opposite in the axial direction, and a second intermediate projection extending from a side surface of the side plate part opposite in the axial direction to a side opposite in the axial direction, arranged radially between the first member and the second member and held in such a way that it can rotate relative to the first member and the second member; and a rotation-holding mechanism that holds the second member on the circumference of the first member in such a way that it can rotate relative to the first member.

Description

Technical area

[0001] The present invention relates to a rotation limiting device for limiting a rotation amount of a rotary member and a steering device. State of the art

[0002] In a rack-and-pinion steering device, when a steering wheel is operated (turned) to the maximum right or left, a rod end held and fixed to an end portion of a rack shaft collides with a housing. As described above, in the rack-and-pinion steering device in which the steering unit and a steered unit are mechanically connected, by limiting the stroke of the rack shaft constituting the steered unit, the number of lock-to-lock turns of the steering wheel (the number of turns of the steering wheel when the steering wheel is operated from fully right or left to fully left or right) is limited.

[0003] In contrast, in a steer-by-wire steering system, the steering unit and the steered unit are not mechanically connected. Therefore, the number of lock-to-lock turns of the steering wheel of the steering unit cannot be limited by limiting the stroke of the rack shaft forming the steered unit.

[0004] Fig. 14 shows a stopper unit 100 for mechanically limiting the number of lock-to-lock turns of a steering wheel in a steer-by-wire type steering device described in Patent Literature 1. Fig. 14 shows Fig. 4 of JP2020-69844A, mirror-image in the left-right direction (left-right symmetrical). The stopper unit 100 includes a first rotary member 101, a housing 102, and a second rotary member 103.

[0005] The first rotary member 101 has a first rotary projection 104 projecting to an axial side on an axial side surface (the left side surface in Fig. 14). The first rotary member 101 is coupled and fixed to an end portion (an end portion on a different axial side) of a steering shaft (not shown) in such a manner that it cannot be rotated relative to the end portion. Thus, the first rotary member 101 rotates together with the steering shaft in response to an operation of the steering wheel.

[0006] The housing 102 has a fixing projection 105 which extends to another axial side on the other axial side surface (the right side surface in Fig. 14) and does not rotate even during use. The steering shaft is held on a radially inner side of the housing 102 such that it can be rotated relative to the housing 102.

[0007] The second rotary member 103 includes a cylindrical portion 106 and a second rotary projection 107 projecting toward a radially outer side from a position in a circumferential direction of an outer peripheral surface of the cylindrical portion 106. The second rotary member 103 is supported around the steering shaft such that it can be rotated relative to the steering shaft, the first rotary member 101, and the housing 102.

[0008] That is, the steering shaft is inserted through the housing 102 and the second rotary member 103 from one axial side to the other axial side, and the first rotary member 101 is coupled to and fixed to the end portion of the steering shaft protruding from an end surface on the other axial side of the second rotary member 103. The steering wheel is held and fixed to an end portion on one axial side of the steering shaft.

[0009] For example, in the steering device with the stopper unit 100 included therein, when the steering wheel is turned to the right (clockwise from the left side to Fig. 14), first the first rotary member 101 rotates together with the steering shaft from an upper side to a lower side in Fig. 14. Then a circumferential side surface (a lower side surface in Fig. 14) of the first rotary projection 104 with the other circumferential side surface (an upper side surface in Fig. 14) of another axial side part of the second rotary projection 107.

[0010] When the steering wheel is further turned to the right from this state, the second rotary member 103 rotates together with the steering shaft and the first rotary member 101 from the upper side to the lower side in Fig. 14. Then, a circumferential side surface of an axial side part of the second rotation projection 107 comes into contact with another circumferential side surface of the fixing projection 105. In this way, operation of the steering wheel is further restricted to the left.

[0011] Patent Literature 2 discloses a small and lightweight multi-rotation limiting mechanism intended to detect rotation limiting operation with high accuracy using a reduction gear mechanism. The multi-rotation limiting mechanism includes: a rotary shaft rotatably provided on a support plate and having a rotation stopper fixed thereto; a plurality of idle rotors loosely fitted on the rotary shaft to receive rotation from the rotation stopper; a stopper rotor loosely fitted on the rotary shaft to be engaged with the idle rotors; a pair of spring members biasing a stopper portion of the stopper rotor in both rotation directions; an electrical sensor for detecting the stopper portion; and engaging portions provided on the rotation stopper, the idle rotor, and the stopper rotor to be engaged with each other.

[0012] Patent Literature 3 discloses a steering device designed to maintain a constant position of a stop sound generated when an operating member is rotated left or right from a neutral position. The steering device keeps the operating member, which is not mechanically connected to a steered wheel, rotatable.The steering device includes: a shaft member that rotates in response to an operation of an operating member; a holding member that rotatably holds the shaft member; a rotational engagement member attached to the shaft member and including a rotational claw that rotates together with the shaft member; a fixed claw that is disposed at a position disengaged from the rotational claw and is fixed to the holding member; an intermediate engagement member that rotates around an axis of the shaft member by engaging with the rotational engagement member and includes an intermediate claw that engages with the rotational claw and the fixed claw in a circumferential direction; and a biasing member that exerts a biasing force to hold the intermediate claw at a predetermined position in the circumferential direction with respect to the fixed claw in a state disengaged from the rotational claw.

[0013] Patent Literature 4 discloses a steer-by-wire type power steering device. The power steering device is provided with a rotation limiting mechanism that limits the steering angle range of a steering wheel. The rotation limiting mechanism includes an integrated rotary part that rotates integrally with a second input shaft, a relative rotary part that rotates relative to the integrated rotary part, and a stopper mechanism that limits rotation of the relative rotary part.

[0014] Patent Literature 5 discloses a steer-by-wire type power steering device. The steering device includes: a first rotary member coupled to a steering shaft and rotating in conjunction with the steering shaft; a second rotary member supported on an outer periphery of the first rotary member and rotating in conjunction with the first rotary member when the steering shaft rotates; and a housing in which the first rotary member and the second rotary member are housed. The housing is coupled to a steering column and restricts rotation of the second rotary member by supporting an outer peripheral surface of the second rotary member against an inner peripheral surface. Reference listPatent literature Patent Literature 1: JP2020-69844A Patent Literature 2: JPH05-042437A Patent Literature 3: JP2021-172231A Patent Literature 4: JP2006-182078A Patent Literature 5: US20220266895 Summary of the inventionTechnical problem

[0015] In the stopper unit 100 of Patent Literature 1, the first rotary member 101 and the second rotary member 103 are rotatably supported around the steering shaft, and the first rotary member 101, the housing 102, and the second rotary member 103 are separated from each other in a state before the steering shaft is rotatably supported radially in the housing 102. Therefore, the handling of the components and the assembly work are complicated.

[0016] The multi-rotation limiting mechanism of Patent Literature 2 is a device for detecting a rotating end of a rotating shaft and does not lock the rotation of the rotating shaft.

[0017] Similar to Patent Literature 1, in the steering device of Patent Literature 3, because the holding member, the rotary engaging member, and the intermediate engaging member are separated from each other before being held by the steering shaft, the handling of the components and the assembly work are complicated.

[0018] And because in the power steering device of Patent Literature 4, the integrated rotating part, the relative rotating part and the stopper mechanism are also separated from each other before being held by the steering shaft, the handling of the components and the assembly work are complicated.

[0019] And also in the steering device of Patent Literature 5, because the first rotary member, the second rotary member and the housing are separated from each other before being held by the steering shaft, the handling of the components and the assembly work are complicated.

[0020] In view of the above circumstances, it is an object of the present invention to provide a rotation limiting device which can be pre-assembled and assembled before being attached to a rotary member and a fixed part. Problem solving

[0021] A rotation limiting device according to one aspect of the present invention comprises a first member, a second member, at least one intermediate member and a rotation holding mechanism.

[0022] The first link has a first projection.

[0023] The second member has a second projection disposed on an axial side relative to the first projection. The second member is disposed around the first member and configured to rotate relative to the first member.

[0024] The at least one intermediate member includes a side plate portion disposed between the first projection and the second projection in an axial direction, a first intermediate projection protruding toward another axial side from another axial side surface of the side plate portion, and a second intermediate projection protruding toward one axial side from one axial side surface of the side plate portion. The at least one intermediate member is disposed between the first member and the second member in a radial direction and is supported relatively rotatably with respect to the first member and the second member.

[0025] The rotational support mechanism is configured to support the second link around the first link such that it can be rotated relative to the first link.

[0026] In the rotation limiting device according to one aspect of the present invention, the first member may include a first side surface facing the one axial side and the first projection protruding from the first side surface to the one axial side, and the second member may include a second side surface facing the other axial side and the second projection protruding from the second side surface to the other axial side.

[0027] In the rotation limiting device according to one aspect of the present invention, the second member may include a second cylindrical part and a second flange part projecting radially inward from an inner peripheral surface of the second cylindrical part, and the second flange part may have the second side surface on another axial side surface.

[0028] In the rotation limiting device according to one aspect of the present invention, the first member may include a first cylindrical part to which the at least one intermediate member is externally fitted so as to be relatively rotatable, and a first flange part protruding to a radially outer side from an outer peripheral surface of the first cylindrical part, wherein the first flange part may have the first side surface on an axial side surface.

[0029] In the rotation limiting device according to one aspect of the present invention, the rotation holding mechanism may comprise a radial rolling bearing having an inner ring externally fitted to the first member, an outer ring fitted into the second member, and a plurality of rolling elements rollably disposed between the inner ring and the outer ring.

[0030] A steering device according to one aspect of the present invention includes: a steering shaft; and a rotation limiting device configured to limit a rotation amount of the steering shaft to a predetermined value.

[0031] The rotation limiting device is implemented by the rotation limiting device according to one aspect of the present invention.

[0032] The first link or the second link is coupled to and fixed on the steering shaft, and the corresponding other of the first link and the second link is held on and fixed to a part which does not rotate even during use. Advantageous effects of the invention

[0033] The rotation limiting device according to one aspect of the present invention can be pre-assembled and assembled before being mounted between a rotating member and a fixed part. Brief description of the drawings Fig. 1 is a schematic view showing an example of a steer-by-wire type steering apparatus including a rotation limiting device according to a first example of an embodiment of the present invention. Fig. 2 is a cross-sectional view showing the rotation limiting device according to the first example of the embodiment of the present invention. Fig. 3 is an exploded perspective view showing the rotation limiting device according to the first example of the embodiment of the present invention. Fig. 4(A) to 4(C) are schematic views showing an operation of the rotation limiting device when a steering wheel is operated from full left to full right. Fig. 5(A) to 5(C) are schematic views showing an operation of the rotation limiting device when the steering wheel is operated from full right to full left. Fig. 6 is a cross-sectional view showing a modification of the first example of the embodiment of the present invention. Fig. 7(A) to 7(D) are schematic views showing an operation of a rotation limiting device when a steering wheel is operated from full left to full right according to the modification. Fig. 8(A) to 8(D) are schematic views showing an operation of a rotation limiting device when a steering wheel is operated from full right to full left according to the modification. Fig. 9 is a cross-sectional view showing a rotation limiting device according to a second example of the embodiment of the present invention. Fig. 10 is a cross-sectional view showing a rotation limiting device according to a third example of the embodiment of the present invention. Fig. 11 is an exploded perspective view showing the rotation limiting device according to the third example of the embodiment of the present invention. Fig. 12 is a cross-sectional view showing a rotation limiting device according to a fourth example of the embodiment of the present invention. Fig. 13 is an exploded perspective view showing the rotation limiting device according to the fourth example of the embodiment of the present invention. Fig. 14 is an exploded view showing a prior art stopper unit. Description of Embodiments[First Example of an Embodiment]

[0034] A first example of an embodiment of the present invention will be described below with reference to Fig. 1 to Fig. 5(C). This example is an example in which a rotation limiting device 4 is incorporated into a steering unit 3 of the steering device 1 to limit the number of lock-to-lock turns of a steering wheel 2 of a steer-by-wire type steering device. The following describes the overall structure of the steering device 1 first, and then the structure and operation of the rotation limiting device 4. <Gesamtaufbau der Lenkvorrichtung 1>

[0035] As in Fig. 1, the steering device 1 includes the steering unit 3 including the steering wheel 2, a steered 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 connectionless structure in which the steering unit 3 and the steered unit 6 are not mechanically but electrically connected to each other via the control unit 7.

[0036] The steering unit 3 comprises a steering column 8, a steering shaft 9, a reaction force exerting device 10 and the rotation limiting device 4.

[0037] The steering column 8 has the shape of a tube and is held on a vehicle body.

[0038] The steering shaft 9 is rotatably supported on a radially inner side of the steering column 8. The steering wheel 2 is held and fixed to an end portion of the steering shaft 9 on a rear side.

[0039] The reaction force applying device 10 is connected to a front end portion of the steering shaft 9. The reaction force applying device 10 includes a reaction force applying motor and a reducer such as a worm gear reducer. The reaction force applying device 10 increases the output torque of the reaction force applying motor by means of the reducer and then applies it to the steering shaft 9.

[0040] The rotation limiting device 4 is provided between the steering shaft 9 and a part that does not rotate even during use, and limits the number of lock-to-lock turns of the steering wheel 2. In this example, the rotation limiting device 4 is provided between a front part of the steering shaft 9 and an end part of the steering column 8 on the front side. The rotation limiting device 4 can be provided in any position as long as the rotation limiting device 4 is located between the steering shaft 9 and a fixed part that does not rotate even during use. In particular, the rotation limiting device 4 can also be provided in a part closer to the steering wheel 2, and for example, between a rear part of the steering shaft 9 and a rear end part of the steering column 8.Alternatively, the rotation limiting device 4 may be provided between the front end portion of the steering shaft 9 and a housing of the reaction force applying device 10. When the rotation limiting device 4 is arranged between the front end portion of the steering shaft 9 and the housing of the reaction force applying device 10, the rotation limiting device 4 can be attached or removed relatively easily. The specific configuration of the rotation limiting device 4 will be explained below.

[0041] The steering unit 3 further comprises a sensor such as a torque sensor or a steering angle sensor, which measures an operation of the steering wheel 2 by a driver.

[0042] The steered unit 6 comprises a gear housing 11 which is held and fixed to the vehicle body, a linear motion member and a steering actuator 12 which linearly drives the linear motion member.

[0043] The linear motion member is implemented by a rack shaft, a worm shaft, or the like. The linear motion member has an axial direction aligned with the width direction of the vehicle body and is held in the transmission case 11 so as to be capable of linear movement in the axial direction. Base end portions of a pair of tie rods 13 are coupled to end portions of the linear motion member on both sides in the axial direction via ball joints (not shown), and a pair of steered wheels 5 are held at end portions of the pair of tie rods 13.

[0044] When the linear motion element is implemented by a rack shaft, the steering actuator 12 includes a pinion shaft meshing with the rack shaft, a steering motor, and a reducer. The output torque of the steering motor is amplified by the reducer and then input to the pinion shaft, which rotates to cause linear movement of the rack shaft.

[0045] When the linear motion element is implemented by a worm shaft, the steering actuator 12 includes a nut that is held around the worm shaft so that it can be rotated relative to the worm shaft, a steering motor, and a reducer. The steering actuator 12 increases the output torque of the steering motor via the reducer and then inputs it to the nut, thereby rotating and driving the nut to move the worm shaft linearly.It should be noted that a feed screw mechanism comprising a worm shaft and a nut may be configured as a sliding worm type feed screw mechanism in which a male threaded portion on an outer peripheral surface of the worm shaft and a female threaded portion on an inner peripheral surface of the nut are directly screwed into each other, or as a ball screw type feed screw mechanism in which a plurality of balls are arranged so as to be able to roll freely between an inner diameter side ball screw groove in an outer peripheral surface of the worm shaft and an outer diameter side ball screw groove in an inner peripheral surface of the nut.

[0046] 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 of the steering unit 3, and a measurement result is output to the control unit 7. The control unit 7 receives various signals indicative of driving conditions, such as a steering torque measured by a torque sensor, a steering angle measured by a steering angle sensor, a vehicle speed, a yaw rate, and an acceleration. The control unit 7 operates the steering actuator 12 in the steered unit 6 based on various signals indicative of the driving conditions. As a result, the linear motion member is displaced in the width direction of the vehicle body, and the pair of tie rods 13 are pushed and pulled to apply a steering angle to the pair of steered wheels 5. <Aufbau der Drehbegrenzungsvorrichtung 4>

[0047] The rotation limiting device 4 of this example is provided between the front part of the steering shaft 9 and the steering column 8, which does not rotate even during use. By limiting the rotation amount of the steering shaft 9 to a predetermined value, the number of lock-to-lock rotations of the steering wheel 2 is limited. In this example, the rotation limiting device 4 includes a first member 14, a second member 15, an intermediate member 16, and a rotation holding mechanism 17.

[0048] In the following description and in this example, an axial side is the front side of the vehicle, ie the left side in Fig. 2 to 13, and the other axial side is the rear side of the vehicle, ie the right side in Fig. 2 to 13, to understand.

[0049] The first member 14 has a first projection 18.

[0050] In this example, the first member 14 includes a first cylindrical part 19 and a first flange part 20 having a hollow circular plate shape projecting to a radially outer side from an outer peripheral surface of an end part of the first cylindrical part 19 on the other axial side.

[0051] The first cylindrical portion 19 is externally fitted and fixed to the front portion of the steering shaft 9 in such a way that it cannot rotate relative to the front portion. Thus, the first link 14 rotates together with the steering shaft 9. In this example, the first cylindrical portion 19 has an outer peripheral surface shaped like a stepped cylindrical surface formed by connecting a large-diameter cylindrical surface portion 21 on the other axial side and a small-diameter cylindrical surface portion 22 on one axial side through an inner-diameter stepped surface 23 facing the one axial side. The large-diameter cylindrical surface portion 21 is formed by a cylindrical surface whose outer diameter does not change in the axial direction.The small-diameter cylindrical surface portion 22 is formed by a cylindrical surface whose outer diameter does not change in the axial direction except for an inner-diameter-side locking groove 24 provided over the entire circumference of an axial side portion. The inner-diameter-side stepped surface 23 is formed by a flat surface orthogonal to a center axis O of the first member 14.

[0052] The first flange portion 20 has a first side surface 25 on one axial side surface and further includes the first protrusion 18 projecting toward one axial side at a position in the circumferential direction of a radially outer portion of the first side surface 25. A radially inner side surface of the first protrusion 18 faces an end portion of the large-diameter cylindrical surface portion 21 on the other axial side with a gap therebetween.

[0053] In this example, the first protrusion 18 has a sector-shaped end surface as viewed from the one axial side. That is, the radially inner side surface and the radially outer side surface of the first protrusion 18 have a circular arc-shaped contour centered on a center axis O of the first member 14 as viewed from the one axial side. The radially outer side surface of the first protrusion 18 is located in a cylindrical surface equal to the outer peripheral surface of the first flange part 20. Thus, the first protrusion 18 does not protrude to a radially outer side from the first flange part 20. Side surfaces of the first protrusion 18 on both sides in the circumferential direction have a linear contour shape extending in a radial direction around the center axis O of the first member 14 as viewed from the one axial side, and extend linearly in the axial direction as viewed from the radially outer side.Thus, the side surfaces of the first projection 18 on both sides in the circumferential direction are located in an imaginary plane containing the center axis O of the first link 14. In this example, a circumferential width of the first projection 18, that is, an angle formed by the side surfaces on both sides in the circumferential direction, is set to 45 degrees.

[0054] The second member 15 has a second projection 26 arranged on one axial side with respect to the first projection 18 and is arranged around the first member 14 coaxially with the first member 14 such that it can rotate relatively with respect to the first member 14.

[0055] In this example, the second member 15 comprises a second cylindrical part 27 and a second flange part 28.

[0056] The second cylindrical part 27 has a stepped cylindrical shape formed by connecting a large-diameter cylindrical part 29 on the other axial side and a small-diameter cylindrical part 30 on one axial side by a connecting plate part 31 having a hollow circular plate shape.

[0057] The large-diameter cylindrical part 29 is formed by a cylindrical surface in which the inner diameter of an inner peripheral surface at another axial side part does not change in the axial direction except for an end part on one axial side to which an end part of the second projection 26 on the radially outer side is connected.

[0058] The small-diameter cylindrical part 30 has an outer diameter-side stepped surface 32 facing one axial side at an end portion on the other axial side of an inner peripheral surface, and has an outer diameter-side locking groove 33 over the entire circumference at an axial side portion of the inner peripheral surface.

[0059] The second flange portion 28 protrudes toward the radially inner side from an inner peripheral surface of the connecting plate portion 31 over the entire circumference. That is, the second flange portion 28 is formed in a hollow circular shape. The second flange portion 28 has a second side surface 34 on the other axial side surface and the second projection 26 at a position of a radially outer part of the second side surface 34. An end portion of the second projection 26 on the radially outer side is connected to an end portion on the one axial side of the inner peripheral surface of the large-diameter cylindrical portion 29.

[0060] In this example, the second protrusion 26 has a sector-shaped end surface when viewed from the other axial side. That is, a radially inner side surface and a radially outer side surface of the second protrusion 26 have a circular arc-shaped contour centered on the center axis O of the second member 15 when viewed from the other axial side. Side surfaces of the second protrusion 26 on both sides in the circumferential direction have a linear contour shape extending in a radiating direction around the center 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 of the second protrusion 26 on both sides in the circumferential direction are located in an imaginary plane containing the center axis O of the second member 15. In this example, a circumferential width of the second protrusion 26 is set to 45 degrees.

[0061] The second member 15 further includes a pair of ear portions 35 projecting toward the radially outer side from two radially opposite positions at one end portion on the other axial side of the large-diameter cylindrical portion 29 of the second cylindrical portion 27. Each of the ear portions 35 has a coupling hole 36 extending therethrough in the axial direction. In this example, the coupling hole 36 is formed as a cylindrical hole whose inner diameter does not change in the axial direction. The rotation limiting device 4 of this example is supported by the steering column 8 and is fixed to the steering column 8 by screwing connecting bolts inserted into the coupling holes 36 of the pair of ear portions 35 of the second member 15 into the column-side screw holes in a front side surface of the steering column 8, so that it does not rotate even during use.

[0062] The intermediate member 16 includes a side plate portion 37 disposed between the first projection 18 and the second projection 26 in the axial direction, a first intermediate projection 38 projecting from another axial side surface of the side plate portion 37 toward the other axial side, and a second intermediate projection 39 projecting from one axial side surface of the side plate portion 37 toward the other axial side. The intermediate member 16 is held coaxially with the first member 14 and the second member 15 and can be rotated relatively with respect to the first member 14 and the second member 15.

[0063] In this example, the intermediate member 16 includes a cylindrical intermediate part 40 externally fitted to the first cylindrical part 19 of the first member 14 so as to be rotatable relative to the first cylindrical part 19, and the side plate part 37 having a hollow circular plate shape projecting to the radially outer side from an outer peripheral surface of an intermediate part of the cylindrical intermediate part 40 in the axial direction.

[0064] Furthermore, the intermediate member 16 includes the first intermediate protrusion 38 protruding toward the other axial side from the other axial side surface of the side plate part 37 at a position in the circumferential direction, and the second intermediate protrusion 39 protruding toward the one axial side from the one axial side surface of the side plate part 37 at a position radially opposite to the first intermediate protrusion 38 (at a position whose phase is offset by 180 degrees in the circumferential direction from the intermediate first protrusion 38). A radially inner end portion of the first intermediate protrusion 38 is connected to another axial side portion of an outer peripheral surface of the intermediate cylindrical part 40, and a radially inner end portion of the second intermediate protrusion 39 is connected to an axial side portion of an outer peripheral surface of the intermediate cylindrical part 40.

[0065] In this example, the first intermediate protrusion 38 has a sector-shaped end surface when viewed from the other axial side. That is, a radially inner side surface and a radially outer side surface of the first intermediate protrusion 38 have a circular arc-shaped contour centered on a center axis O of the intermediate member 16 when viewed from the other axial side. A radially outer side surface of the first intermediate protrusion 38 is located in a cylindrical surface equal to the outer peripheral surface of the side plate part 37. That is, the intermediate first protrusion 38 is formed integrally with the side plate part 37 and does not protrude to the radially outer side of the side plate part 37. The first intermediate protrusion 38 is arranged on the radially inner side of the outer peripheral surface of the side plate part 37.The radially outer side surface of the first intermediate protrusion 38 does not necessarily have to be located in the same cylindrical surface as the outer peripheral surface of the side plate part 37, as long as the radially outer side surface of the first intermediate protrusion 38 is located on the radially inner side of the outer peripheral surface of the side plate part 37. Side surfaces of the first intermediate protrusion 38 on both sides in the circumferential direction have a linear contour shape extending in a radial direction around the center axis O of the intermediate member 16 as viewed from the other axial side, and extend linearly in the axial direction as viewed from the radially outer side. That is, the side surfaces of the first intermediate protrusion 38 on both sides in the circumferential direction are located in the imaginary plane containing the center axis O of the intermediate member 16.In this example, a circumferential width of the first intermediate projection 38 is set to 45 degrees.

[0066] In this example, the second intermediate protrusion 39 has a sector-shaped end surface when viewed from one axial side. That is, a radially inner side surface and a radially outer side surface of the second intermediate protrusion 39 have a circular arc-shaped contour centered on a center axis O of the intermediate member 16 when viewed from one axial side. A radially outer side surface of the second intermediate protrusion 39 is located in a cylindrical surface equal to the outer peripheral surface of the side plate part 37. That is, the second intermediate protrusion 39 is formed integrally with the side plate part 37 and does not protrude to the radially outer side of the side plate part 37. That is, the second intermediate protrusion 39 is arranged on the radially inner side of the outer peripheral surface of the side plate part 37.The radially outer side surface of the second intermediate protrusion 39 does not necessarily have to be located in the same cylindrical surface as the outer peripheral surface of the side plate part 37, as long as the radially outer side surface of the second intermediate protrusion 39 is located on the radially inner side of the outer peripheral surface of the side plate part 37. Side surfaces of the second intermediate protrusion 39 on both sides in the circumferential direction have a linear contour shape extending in a radial direction around the center axis O of the intermediate member 16 as viewed from one axial side, and extend linearly in the axial direction as viewed from the radially outer side. That is, the side surfaces of the second intermediate protrusion 39 on both sides in the circumferential direction are located in the imaginary plane containing the center axis O of the intermediate member 16.In this example, a circumferential width of the second intermediate projection 39 is set to 45 degrees.

[0067] The rotational holding mechanism 17 holds the second link 15 around the first link 14 such that relative rotation with respect to the first link 14 is possible and inadvertent removal is prevented. In this example, the rotational holding mechanism 17 is arranged between the small-diameter cylindrical surface portion 22 of the first link 14 and the inner peripheral surface of the small-diameter cylindrical portion 30 of the second link 15.

[0068] In this example, the rotary retaining mechanism 17 comprises a radial rolling bearing 41 and two retaining rings 42a and 42b, each having a segmented ring shape (with a C-shaped end surface as viewed in the axial direction).

[0069] The radial rolling bearing 41 comprises an inner ring 43, an outer ring 44 and a plurality of rolling elements 45.

[0070] The inner ring 43 has an inner ring race 46 on an outer peripheral surface and is externally fitted to the small-diameter cylindrical surface portion 22 of the first member 14 without rattling. Furthermore, the inner ring 43 abuts against the inner-diameter-side stepped surface 23 on another axial side surface and abuts against the retaining ring 42a locked with the inner-diameter-side locking groove 24 on one axial side surface. 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 locked with the inner-diameter-side locking groove 24. This positions the inner ring 43 with respect to the first member 14.

[0071] The outer ring 44 has an outer ring race 47 on an inner peripheral surface and is rattle-free fitted into the small-diameter cylindrical portion 30 of the second member 15. Furthermore, the outer ring 44 abuts against the outer-diameter-side stepped surface 32 on another axial side surface and abuts against the retaining ring 42b locked at the outer-diameter-side locking groove 33 on one axial side surface. 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 locked at the outer-diameter-side locking groove 33. This positions the outer ring 44 with respect to the second member 15.

[0072] The rolling elements 45 are arranged between the inner raceway 46 of the inner ring 43 and the outer raceway 47 of the outer ring 44 such that they can roll freely. In this example, balls are used as the rolling elements 45. The radial rolling bearing 41 is thus implemented by a radial ball bearing.

[0073] The rotation limiting device 4 of this example is assembled by disposing the rotation holding mechanism 17 between the small-diameter cylindrical surface part 22 of the first member 14 and the inner peripheral surface of the small-diameter cylindrical part 30 of the second member 15 in a state in which the intermediate cylindrical part 40 of the intermediate member 16 is externally fitted to the large-diameter cylindrical surface part 21 of the first member 14 so as to be rotated without rattling, and the second member 15 is arranged around the first member 14 and the intermediate member 16.

[0074] When the rotation limiting device 4 is assembled, the inner peripheral surface of the large-diameter cylindrical part 29 of the second member 15 faces the outer peripheral surface of the first flange part 20 of the first member 14 and the radially outer side surface of the first projection 18, the outer peripheral surface of the side plate part 37 of the intermediate member 16, the radially outer side surface of the first intermediate projection 38 and the radially outer side surface of the second intermediate projection 39 at intervals, and an inner peripheral surface of the second flange part 28 faces an end part of the large-diameter cylindrical surface part 21 of the first member 14 on one axial side at an interval.A radially inner part of the first side surface 25 is in sliding contact with or opposes an end surface of the cylindrical intermediate part 40 on the other axial side, and a radially inner part of the second side surface 34 is in sliding contact with or opposes an end surface of the cylindrical intermediate part 40 on the one axial side. One axial side surface of the first projection 18 faces the other axial side surface of the side plate part 37 with a gap therebetween, and another axial side surface of the second projection 26 faces the one axial side surface of the side plate part 37 with a gap therebetween. Furthermore, another axial side surface of the first intermediate protrusion 38 faces the first side surface 25 with a gap therebetween, and one axial side surface of the second intermediate protrusion 39 faces the second side surface 34 with a gap therebetween. <Betrieb der Drehbegrenzungsvorrichtung 4>

[0075] The operation of the rotation limiting device 4 according to this example will be described below with reference to Fig. 4(A) to Fig. 5(C). Fig. 4(A) to Fig. 5(C) are views schematically showing the first projection 18 of the first link 14, the second projection 26 of the second link 15, and the intermediate link 16 as viewed from the radially outer side. In the following description, a circumferential side means a front side in the counterclockwise direction from a driver sitting on a driver's seat, that is, the lower side in Fig. 4(A) to Fig. 5(C), and the other peripheral side is a front side in a clockwise direction from the driver sitting on the driver's seat, ie the upper side in Fig. 4(A) to Fig. 5(C), to understand

[0076] First, when the steering wheel 2 is operated from the full left (in the counterclockwise direction as viewed from the driver sitting on the driver's seat) to the full right (in the clockwise direction as viewed from the driver sitting on the driver's seat), the rotation limiting device 4 is operated in the order of Fig. 4(A) → Fig. 4(B) → Fig. 4(C).

[0077] This means that in a state where the steering wheel 2 is fully turned to the left as in Fig. 4(A), one circumferential side surface of the first projection 18 is in contact with another circumferential side surface of the first intermediate projection 38, and another circumferential side surface of the second projection 26 is in contact with a circumferential side surface of the second intermediate projection 39.

[0078] If from this state the steering wheel 2 is turned as shown by the arrow in Fig. 4(A) and the steering shaft 9 is rotated in the clockwise direction, only the first link 14 rotates in the clockwise direction (toward the other circumferential side), while the other circumferential side surface of the second projection 26 remains in contact with the one circumferential side surface of the second intermediate projection 39. Then, when the first link 14 is rotated by an angle smaller than 360 degrees by the sum of the circumferential width of the first projection 18 and the circumferential width of the first intermediate projection 38, that is, by 270 degrees in this example, as shown in Fig. 4(B), the other circumferential side surface of the first projection 18 comes into contact with the one circumferential side surface of the first intermediate projection 38. In this state, the steering wheel 2 is located at the center and the pair of steered wheels 5 are aligned in the straight-ahead direction.

[0079] If the steering wheel 2 is out of the Fig. 4(B) shown state as indicated by the arrow in Fig. 4(B), one circumferential side surface of the first intermediate projection 38 is pressed to the other circumferential side by the other circumferential side surface of the first projection 18. As a result, the first link 14 and the intermediate link 16 rotate together in the clockwise direction (toward the other circumferential side). Then, when the first link 14 and the intermediate link 16 rotate in the clockwise direction by an angle smaller than 360 degrees by the sum of the circumferential width of the second projection 26 and the circumferential width of the second intermediate projection 39, that is, by 270 degrees in this example, as shown in Fig. 4(C), another circumferential side surface of the second intermediate projection 39 comes into contact with one circumferential side surface of the second projection 26. When the other circumferential side surface of the second intermediate projection 39 comes into contact with the one circumferential side surface of the second projection 26, rotation of the intermediate member 16 in the clockwise direction with respect to the second member 15 is prevented. When rotation of the intermediate member 16 in the clockwise direction is prevented, further rotation of the first member 14 in the clockwise direction is prevented.

[0080] Alternatively, if the first member 14 is moved in the clockwise direction by the operation of the steering wheel 2 from the Fig. 4(A), the intermediate member 16 is rotated together with the first member 14 due to a frictional force acting between an outer peripheral surface of the first cylindrical portion 19 and an inner peripheral surface of the intermediate cylindrical portion 40, and the first member 14 and the intermediate member 16 rotate together. Then, the other peripheral side surface of the second intermediate projection 39 comes into contact with the one peripheral side surface of the second projection 26, and further rotation of the intermediate member 16 in the clockwise direction with respect to the second member 15 is prevented. When the steering wheel 2 is further operated to the right from this state, only the first member 14 rotates in the clockwise direction.Then, the other circumferential side surface of the first projection 18 comes into contact with the one circumferential side surface of the first intermediate projection 38, and further rotation of the first member 14 in the clockwise direction with respect to the intermediate member 16 is prevented.

[0081] In any case, if further rotation of the first member 14 in the clockwise direction is prevented, further rotation of the steering shaft 9 and the steering wheel 2 held by the steering shaft 9 and fixed thereto in the clockwise direction is prevented.

[0082] Then, when the steering wheel 2 is operated from fully right to fully left, the rotation limiting device 4 is actuated as shown in the order of Fig. 5(A) → Fig. 5(B) → Fig. 5(C).

[0083] This means that in a state where the steering wheel 2 is as in Fig. 5(A), the other peripheral side surface of the first projection 18 is in contact with the one peripheral side surface of the first intermediate projection 38, and the one peripheral side surface of the second projection 26 is in contact with the other peripheral side surface of the second intermediate projection 39.

[0084] If from this state the steering wheel 2 is turned to the left and the steering shaft 9 is moved as shown by the arrow in Fig. 5(A), only the first member 14 rotates in the counterclockwise direction (toward one circumferential side), while the one circumferential side surface of the second projection 26 remains in contact with the other circumferential side surface of the second intermediate projection 39. Then, when the first member 14 is rotated by an angle smaller than 360 degrees by the sum of the circumferential width of the first projection 18 and the circumferential width of the first intermediate projection 38, ie, 270 degrees in this example, as shown in Fig. 5(B), one circumferential side surface of the first projection 18 comes into contact with the other circumferential side surface of the first intermediate projection 38. In this state, the steering wheel 2 is located at the center and the pair of steered wheels 5 are aligned in a straight-ahead direction.

[0085] If the steering wheel 2 is out of the Fig. 5(B) shown state as indicated by the arrow in Fig. 5(B), the other circumferential side surface of the first intermediate projection 38 is pressed toward the one circumferential side by the one circumferential side surface of the first projection 18. As a result, the first link 14 and the intermediate link 16 rotate together in the counterclockwise direction (toward the one circumferential side). Then, when the first link 14 and the intermediate link 16 rotate in the counterclockwise direction by an angle smaller than 360 degrees by the sum of the circumferential width of the second projection 26 and the circumferential width of the second intermediate projection 39, that is, by 270 degrees in this example, as shown in Fig. 5(C), one circumferential side surface of the second intermediate projection 39 comes into contact with the other circumferential side surface of the second projection 26. When one circumferential side surface of the second intermediate projection 39 comes into contact with the other circumferential side surface of the second projection 26, further rotation of the intermediate member 16 in the counterclockwise direction with respect to the second member 15 is prevented. When rotation of the intermediate member 16 in the counterclockwise direction is prevented, further rotation of the first member 14 in the counterclockwise direction is prevented.

[0086] If the first member 14 rotates in the counterclockwise direction because the steering wheel 2 is out of the Fig. 5(A), the intermediate link 16 is rotated together with the first link 14 because a frictional force acts between an outer peripheral surface of the first cylindrical portion 19 and an inner peripheral surface of the intermediate cylindrical portion 40, and the first link 14 and the intermediate link 16 rotate together. Then, one peripheral side surface of the second intermediate projection 39 comes into contact with the other peripheral side surface of the second projection 26, and further rotation of the intermediate link 16 in the counterclockwise direction with respect to the second link 15 is prevented. When the steering wheel 2 is further operated to the left from this state, only the first link 14 rotates in the counterclockwise direction.Then, one circumferential side surface of the first projection 18 comes into contact with the other circumferential side surface of the first intermediate projection 38, and further rotation of the first member 14 in the counterclockwise direction with respect to the intermediate member 16 is prevented.

[0087] In any case, if further rotation of the first member 14 in the counterclockwise direction is prevented, further rotation of the steering shaft 9 and the steering wheel 2 held by the steering shaft 9 and fixed thereto in the counterclockwise direction is prevented.

[0088] In the rotation limiting device 4 of this example, the second link 15 can be held around the first link 4 by the rotation holding mechanism 17 to allow relative rotation with respect to the first link 14 and prevent accidental separation. Specifically, the rotation holding mechanism 17 is disposed between the small-diameter cylindrical surface portion 22 of the first link 14 and the inner peripheral surface of the small-diameter cylindrical portion 30 of the second link 15 in a state where the intermediate cylindrical portion 40 of the intermediate link 16 is externally fitted to the large-diameter cylindrical surface portion 21 of the first link 14 so as to be relatively rotated without rattling, and the second link 15 is disposed around the first link 14 and the intermediate link 16.Therefore, the rotation limiting device 4 can be mounted even in a state before the first member 14 is coupled to and fixed on the steering shaft 9, and the second member 15 is held by the steering column 8 and fixed on the steering shaft 9. This simplifies the handling of the components and the assembly work of the rotation limiting device 4 to the steering unit 3, and simplifies the handling of the rotation limiting device 4. Furthermore, the inventions of the above-mentioned Patent Literatures 1 to 5 do not have a mechanism such as the rotation holding mechanism 17 of the present invention that holds the second member 15 around the first member 14 to allow relative rotation and prevent accidental separation, so that the handling of the components and the assembly work are complicated in the prior art.

[0089] As described above, in the rotation limiting device 4 according to this example, the intermediate member 16 includes the first intermediate side projection 38 projecting from the other axial side surface of the side plate part 37 to the other axial side, and the second intermediate side projection 39 projecting from the one axial side surface of the side plate part 37 to the one axial side.

[0090] Furthermore, Patent Literature 2 states that the idle rotors 14 to 16 have the engaging parts 14a to 16a and 14b to 16b, but the multi-rotation limiting mechanism of Patent Literature 2 is originally a means for detecting a rotation end of a rotary shaft, does not lock the rotation of the rotary shaft, and has a different configuration and function from the first intermediate protrusion 38 and the second intermediate protrusion 39 of the present invention.

[0091] Patent Literature 3 discloses a first engagement member 141 formed integrally with an intermediate engagement member 150 and extending in the axial direction. It serves to prevent the occurrence of an impact noise when the first engagement member 141 comes into contact with the first and second arms 161 and 162 of a biasing member 160, and has a different function from the first intermediate projection 38 and the second intermediate projection 39 of the present invention.

[0092] Patent Literature 4 discloses that a first contact portion 412 protrudes from an integrated rotary portion 410 only on one axial side. However, no member protruding from the integrated rotary portion 410 on the other axial side is disclosed.

[0093] Fig. 8 of Patent Literature 5 discloses an outer peripheral support portion 175 formed to protrude to both sides in the axial direction of a second rotary member 170. However, the outer peripheral support portion 175 protrudes to the radially outer side from an outer peripheral side of the second rotary member 170. Therefore, since the outer peripheral support portion 175 is not disposed on the radially inner side of an outer peripheral surface of the second rotary member 170, compactness and strength are disadvantageous. Therefore, when the outer peripheral support portion 175 repeatedly comes into contact with a first support portion 161 of a first rotary member 160 or an inner peripheral support portion 189 of a housing 180, the outer peripheral support portion 175 may be deformed or the outer peripheral support portion 175 may rotate from the radial direction.According to the present invention, however, the first intermediate protrusion 38 and the second intermediate protrusion 39 are formed integrally with the side plate part 37 and do not protrude toward the radially outer side of the side plate part 37, so the above-mentioned problem is unlikely to occur. A . Fig. 3 of Patent Literature 5 protrudes only on one axial side, and is thus different from the first intermediate protrusion 38 and the second intermediate protrusion 39 of the present invention, which protrude on both sides in the axial direction.

[0094] Furthermore, in the rotation limiting device 4 of this example, the rotation amount of the steering shaft 9 coupled to and fixed to the first link 14 can be adjusted by changing the number of intermediate links 16 arranged between the first projection 18 and the second projection 26 in the axial direction. Therefore, in the rotation limiting device 4 of this example, the degree of freedom in setting the possible rotation amount of the steering shaft 9 can be improved. In particular, as the number of intermediate links 16 is increased, the rotation amount of the steering shaft 9 can be increased.

[0095] Fig. 6 to Fig. 8(D) shows a rotation limiting device 4a comprising two intermediate members 16a and 16b. The intermediate members 16a and 16b each include: side plate portions 37a and 37b having a hollow circular plate shape; first intermediate protrusions 38a and 38b projecting toward the other axial side from corresponding other axial side surfaces of the side plate portions 37a and 37b at a position in the circumferential direction; and second intermediate protrusions 39a and 39b projecting toward the one axial side from corresponding one axial side surfaces at a position radially opposite to the first intermediate protrusions 38a and 38b. Thus, the intermediate members 16a and 16b do not include the cylindrical intermediate portion 40 provided on the intermediate member 16 according to the first example of the embodiment.The two intermediate members 16a and 16b are arranged in a row in the axial direction and externally fitted to 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 designated by different reference numerals for clarity, 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 by the size of the added intermediate members 16a and 16b than in the structure according to the first example of the embodiment.

[0096] The rotation limiting device 4a according to this modification includes three annular clearance adjusting members 48. Of the three clearance adjusting members 48, the clearance adjusting member 48 on the other axial side is sandwiched in the axial direction between a radially inner part of another axial side surface of the side plate part 37a of the intermediate member 16a on the other axial side and a radially inner part of an axial side surface (the first side surface 25) of the first flange part 20 of the first member 14. The clearance adjusting member 48 in the middle is sandwiched in the axial direction between a radially inner part of an axial side surface of the side plate part 37a of the intermediate member 16a on the other axial side and a radially inner part of another axial side surface of the side plate part 37b of the intermediate member 16b on the one axial side.The one-axial-side clearance adjusting member 48 is sandwiched in the axial direction between a radially inner part of one axial side surface of the side plate part 37b of the one-axial-side intermediate member 16b and a radially inner part of another axial side surface (the second side surface 34) of the second flange part 28 of the second member 15.

[0097] In this modification, each of the clearance adjustment members 48 is formed by a spacer made of a material having a small friction coefficient with respect to one axial side surface of the first flange portion 20 and the other axial side surface of the second flange portion 28 and / or the side plate portions 37a, 37b. Specifically, for example, each of the clearance adjustment members 48 may be formed as a disk made of synthetic resin, an oil-retaining metal, or the like.

[0098] If in the steering unit 3 (see Fig. 1) which includes the rotation limiting device 4a according to this modification, the steering wheel 2 is operated from full left to full right, the rotation limiting device 4a is actuated as shown in the order of Fig. 7(A) → Fig. 7(B) → Fig. 7(C) → Fig. 7(D).

[0099] In a state where the steering wheel 2 as in Fig. 7(A) is operated to the full left, one circumferential side surface of the first projection 18 is in contact with another circumferential side surface of the first intermediate projection 38a of the intermediate member 16a on the other axial side, one circumferential side surface of the second intermediate projection 39a of the intermediate member 16a on the other axial side is in contact with another circumferential side surface of the first intermediate projection 38b of the intermediate member 16b on the one axial side, and one circumferential side surface of the second intermediate projection 39b of the intermediate member 16b on the one axial side is in contact with the other circumferential side surface of the second projection 26.

[0100] If from this state the steering wheel 2 is turned as shown by the arrow in Fig. 7(A) and the steering shaft 9 is rotated in the clockwise direction, only the first link 14 rotates in the clockwise direction (toward the other circumferential side), while the one circumferential side surface of the second intermediate projection 39a of the intermediate link 16a on the other axial side remains in contact with the other circumferential side surface of the first intermediate projection 38b of the intermediate link 16b on the one axial side, and the one circumferential side surface of the second intermediate projection 39b of the intermediate link 16b on the one axial side remains in contact with the other circumferential side surface of the second projection 26. When the first link 14 rotates in the clockwise direction by an angle smaller than 360 degrees by the sum of the circumferential width of the first projection 18 and the circumferential width of the first intermediate projection 38a as shown in Fig. 7(B), the other circumferential side surface of the first projection 18 comes into contact with a circumferential side surface of the first intermediate projection 38a of the intermediate member 16a on the other axial side.

[0101] If the steering wheel 2 is out of the Fig. 7(B) shown condition as in Fig. 7(B), the one circumferential side surface of the first intermediate projection 38a of the intermediate member 16a on the other axial side is pressed toward the other circumferential side by the other circumferential side surface of the first projection 18. Therefore, when the one circumferential side surface of the second intermediate projection 39b of the intermediate member 16b on the one axial side remains in contact with the other circumferential side surface of the second projection 26, the first member 14 and the intermediate member 16a on the other axial side rotate together in the clockwise direction (toward the other circumferential side).Then, when the first link 14 and the intermediate link 16a on the other axial side rotate in the clockwise direction by an angle smaller than 360 degrees by the sum of a circumferential width of the second intermediate projection 39a of the intermediate link 16a on the other axial side and a circumferential width of the first intermediate projection 38b of the intermediate link 16b on one axial side as shown in . Fig. 7(C), another circumferential side surface of the second intermediate projection 39a of the intermediate member 16a on the other axial side comes into contact with a circumferential side surface of the first intermediate projection 38b of the intermediate member 16b on the one axial side.

[0102] When the first link 14 and the intermediate link 16a on the other axial side rotate together in the clockwise direction because the steering wheel 2 is released from the Fig. 7(C) shown state as indicated by the arrow in Fig. 7(C), the one circumferential side surface of the first intermediate projection 38b of the intermediate member 16b on one axial side is pressed toward the other circumferential side by the other circumferential side surface of the second intermediate projection 39a of the intermediate member 16a on the other axial side. As a result, the first member 14 and the two intermediate members 16a and 16b rotate together in the clockwise direction (toward the other circumferential side). Therefore, when the first member 14 and the two intermediate members 16a and 16b rotate in the clockwise direction by an angle smaller than 360 degrees, the sum of a circumferential width of the second intermediate projection 39b of the intermediate member 16b on one axial side and the circumferential width of the second projection 26 as shown in Fig. 7(D), the other circumferential side surface of the second intermediate projection 39b of the intermediate member 16b on the one axial side comes into contact with the one circumferential side surface of the second projection 26. As a result, further rotation of the intermediate member 16b on the one axial side in the clockwise direction with respect to the second member 15 is prevented. When rotation of the intermediate member 16b on the one axial side in the clockwise direction is prevented, further rotation of the intermediate member 16a on the other axial side in the clockwise direction is prevented.When rotation of the intermediate member 16a on the other axial side in the clockwise direction is prevented, further rotation of the first member 14 in the clockwise direction is prevented, and further rotation of the steering shaft 9 and the steering wheel 2 held by and fixed to the steering shaft 9 in the clockwise direction is prevented.

[0103] On the other hand, when the steering wheel 2 is operated from fully right to fully left, the rotation limiting device 4a is actuated as shown in the order of Fig. 8(A), Fig. 8(B), Fig. 8(C) and Fig. 8(D).

[0104] In a state where the steering wheel 2 as in Fig. 8(A), the other circumferential side surface of the first projection 18 is in contact with a circumferential side surface of the first intermediate projection 38a of the intermediate member 16a on the other axial side, another circumferential side surface of the second intermediate projection 39a of the intermediate member 16a on the other axial side is in contact with a circumferential side surface of the first intermediate projection 38b of the intermediate member 16b on the one axial side, and another circumferential side surface of the second intermediate projection 39b of the intermediate member 16b on the one axial side is in contact with the one circumferential side surface of the second projection 26.

[0105] If from this state the steering wheel 2 is turned as shown by the arrow in Fig. 8(A) and the steering shaft 9 is rotated in the counterclockwise direction, only the first link 14 rotates in the counterclockwise direction (toward one circumferential side), while the other circumferential side surface of the second intermediate projection 39a of the intermediate link 16a on the other axial side remains in contact with the one circumferential side surface of the first intermediate projection 38b of the intermediate link 16b on the one axial side, and the other circumferential side surface of the second intermediate projection 39b of the intermediate link 16b on the one axial side remains in contact with the one circumferential side surface of the second projection 26. When the first link 14 rotates in the counterclockwise direction by an angle smaller than 360 degrees by the sum of the circumferential width of the first projection 18 and the circumferential width of the first intermediate projection 38a as shown in Fig. 8(B), one circumferential side surface of the first projection 18 comes into contact with another circumferential side surface of the first intermediate projection 38a of the intermediate member 16a on the other axial side.

[0106] If the steering wheel 2 is out of the Fig. 8(B) shown state as indicated by the arrow in Fig. 8(B), the other circumferential side surface of the first intermediate projection 38a of the intermediate member 16a on the other axial side is pressed toward the one circumferential side by the one circumferential side surface of the first projection 18. Therefore, when the other circumferential side surface of the second intermediate projection 39b of the intermediate member 16b on the one axial side remains in contact with the one circumferential side surface of the second projection 26, the first member 14 and the intermediate member 16a on the other axial side rotate together in the counterclockwise direction (toward the one circumferential side).Then, when the first link 14 and the intermediate link 16a on the other axial side rotate in the counterclockwise direction by an angle smaller than 360 degrees by the sum of a circumferential width of the second intermediate projection 39a of the intermediate link 16a on the other axial side and a circumferential width of the first intermediate projection 38b of the intermediate link 16b on the other axial side as shown in . Fig. 8(C), one circumferential side surface of the second intermediate projection 39a of the intermediate member 16a on the other axial side comes into contact with another circumferential side surface of the first intermediate projection 38b of the intermediate member 16b on the one axial side.

[0107] When the first link 14 and the intermediate link 16a on the other axial side rotate together in the counterclockwise direction because the steering wheel 2 is released from the Fig. 8(C) shown state as indicated by the arrow in Fig. 8(C), the other circumferential side surface of the first intermediate projection 38b of the intermediate member 16b on the one axial side is pressed toward the one circumferential side by the one circumferential side surface of the second intermediate projection 39a of the intermediate member 16a on the one axial side. As a result, the first member 14 and the two intermediate members 16a and 16b rotate together in the counterclockwise direction (toward the one circumferential side). Then, when the first member 14 and the two intermediate members 16a and 16b rotate in the counterclockwise direction by an angle smaller than 360 degrees by the sum of a circumferential width of the second intermediate projection 39b of the intermediate member 16b on the one axial side and the circumferential width of the second projection 26 as shown in Fig. 8(D), a circumferential side surface of the second intermediate projection 39b of the intermediate member 16b on one axial side comes into contact with the other circumferential side surface of the second projection 26. As a result, further rotation of the intermediate member 16b on one axial side in the counterclockwise direction with respect to the second member 15 is prevented. When rotation of the intermediate member 16b on one axial side in the counterclockwise direction is prevented, further rotation of the intermediate member 16a on the other axial side in the counterclockwise direction is prevented.When rotation of the intermediate member 16a on the other axial side in the counterclockwise direction is prevented, further rotation of the first member 14 in the counterclockwise direction is prevented, and further rotation of the steering shaft 9 and the steering wheel 2 held by and fixed to the steering shaft 9 in the counterclockwise direction is prevented.

[0108] In this modification, the intermediate member 16a on one axial side and / or the intermediate member 16b on the other axial side can also be rotated together with the first member 14 due to a frictional force acting between the outer peripheral surface of the first cylindrical part 19 of the first member 14 and an inner peripheral surface of the side plate part 37a of the intermediate member 16a on the other axial side and / or an inner peripheral surface of the side plate part 37b of the intermediate member 16b on the one axial side. In this case, the operation order of the rotation limiting device 4a can be different from the example of Fig. 7 and Fig. be 8.

[0109] As described above, the rotation limiting device 4 (4a) according to this example can increase the rotation amount of the steering shaft 9 by increasing the number of the intermediate members 16 (16a, 16b) whose first intermediate projections 38 (38a, 38b) protrude to the other axial side and whose second intermediate projections 39 (39a, 39b) protrude to the one axial side, and arranging the intermediate members 16 (16a, 16b) in a row in the axial direction. In particular, when the circumferential width W of the first projection 18, the second projection 26, the first intermediate projection 38 (38a, 38b) and the second intermediate projection 39 (39a, 39b) are all the same, with each added intermediate member 16, the rotation amount of the steering shaft 9 can be increased by an angle which is twice the circumferential width W (2W) smaller than 360 degrees.

[0110] When the circumferential width W is 45 degrees, with each added intermediate link 16 (16a, 16b), the rotation amount of the steering shaft 9 can be increased by 270 degrees, and the number of lock-to-lock rotations of the steering wheel 2 can be increased by 0.75. For example, as in the first example of the embodiment, in the rotation limiting device 4 including only a single intermediate link 16, the rotation amount of the steering shaft 9 is 540 degrees (the number of lock-to-lock rotations of the steering wheel 2 is 1.5), while in the modification, in the rotation limiting device 4a with the two intermediate links 16a and 16b, the rotation amount of the steering shaft 9 can be set to 810 degrees (the number of lock-to-lock rotations of the steering wheel 2 is 2.25).

[0111] The rotation limiting device 4a of this modification includes the clearance adjusting members 48 at a part between the first member 14 and the intermediate member 16a on one axial side, a part between the intermediate member 16a on one axial side and the intermediate member 16b on the other axial side, and a part between the intermediate member 16b on the other axial side and the second member 15. This can prevent rattling of the intermediate members 16a and 16b with respect to the first member 14 and the second member 15 in the axial direction, and can 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 excessively large.

[0112] Some or all of the clearance adjustment members may be a preload applying member having elasticity in the axial direction. The preload applying member may, for example, be a disc spring interposed between a pair of resin washers. When the preload applying member is interposed between the second flange part and the side plate part, the preload applying member may be implemented by interposing a disc spring between a metal washer on one axial side and a resin washer on the other axial side. This can prevent the rotational resistance between the first member and the second member and the intermediate member from becoming excessively large, and at the same time, can provide the function of applying preload between the first member and the second member.

[0113] Furthermore, in the rotation limiting device 4a according to this modification, the two intermediate links 16a and 16b have the same shape. This means that in the rotation limiting device according to the invention, the rotation amount of the rotary link can be adjusted by increasing or decreasing the number of intermediate links having the same shape. Therefore, with the rotation limiting device of the present invention, an unnecessary increase in manufacturing costs, parts handling costs, and assembly costs can be avoided, and an increase in the manufacturing cost of the rotation limiting device can be avoided.

[0114] Furthermore, in the rotation limiting device 4 of the example, it is not necessary to increase the coupling strength of the first member 14 with respect to the steering shaft 9 in the axial direction and the coupling strength of the second member 15 with respect to the steering column 8 in the axial direction.

[0115] That is, in the stopper unit 100 of a prior art structure according to Patent Literature 1 of Fig. 14 Side surfaces of the first rotary protrusion 104 on both sides in the circumferential direction, side surfaces of the fixing protrusion 105 on both sides in the circumferential direction, side surfaces of the fixing protrusion 105 on both sides in the circumferential direction, and side surfaces of the second rotary protrusion 107 on both sides in the circumferential direction are inclined with respect to the axial direction as viewed from the radially outer side. Therefore, when the first rotary member 101 rotates, a force is exerted between the first rotary member 101 and the second rotary member 103 and / or between the second rotary member 103 and the housing 102 in a direction in which they are moved away from each other in the axial direction. Accordingly, it is necessary to sufficiently increase the coupling strength of the first rotary member 101 with respect to the steering shaft in the axial direction and the coupling strength of the housing 102 with respect to the vehicle body in the axial direction.

[0116] Furthermore, in the rotation limiting device 4 of this example, the side surfaces of the first protrusion 18 on both sides in the circumferential direction, the side surfaces of the second protrusion 26 on both sides in the circumferential direction, the side surfaces of the intermediate first protrusion 38 on both sides in the circumferential direction, and the side surfaces of the second intermediate protrusion 39 on both sides in the circumferential direction extend linearly in the axial direction from the radial direction. Therefore, even when the first link 14 rotates during rotation of the steering shaft 9, no force acts in the axial direction between the first link 14 and the intermediate link 16 and between the intermediate link 16 and the second link 15.Therefore, it is not necessary to increase the coupling strength of the first member 14 with respect to the steering shaft 9 in the axial direction and the coupling strength of the second member 15 with respect to the steering column 8 in the axial direction, and an unnecessary increase in the manufacturing cost of the steering device 1 with the rotation limiting device 4 incorporated therein can be avoided.

[0117] In the rotation limiting device 4 of this example, the radial rolling bearing 41 of the rotation support mechanism 17 is implemented by a ball bearing that uses balls as a plurality of rolling elements 45. When implementing the present invention, the radial rolling bearing may be a radial rolling bearing that uses rollers as rolling elements or a radial needle bearing that uses needles as rolling elements.

[0118] Furthermore, in this example, displacement of the inner ring 43 of the radial rolling bearing 41 toward one axial side is prevented by the retaining ring 42a provided at the inner diameter-side locking groove 24 in the small-diameter cylindrical surface portion 22 of the first member 14. That is, the inner ring 43 is sandwiched in the axial direction between the retaining ring 42a and the inner diameter-side stepped surface 23 on an outer peripheral surface of the first member 14 and positioned in the axial direction. In one implementation of the present invention, displacement toward one axial side can also be prevented by externally fitting the inner ring of the radial rolling bearing to the first member by press fitting.

[0119] Displacement of the outer ring 44 of the radial rolling bearing 41 toward one axial side is prevented by the retaining ring 42b, which is locked at the inner diameter-side locking groove 33 in the inner peripheral surface of the small-diameter cylindrical portion 30 of the second member 15. That is, the outer ring 44 is sandwiched in the axial direction between the retaining ring 42b and the outer diameter-side stepped surface 32 on the inner peripheral surface of the second member 15 and positioned in the axial direction. In one implementation of the present invention, displacement toward one axial side can also be prevented by press-fitting the outer ring of the radial rolling bearing into the second member.

[0120] Alternatively, the rotational support mechanism may comprise a radial sliding bearing (bushing) instead of the radial rolling bearing. In this case, a radially inner part of the radial sliding bearing is sandwiched in the axial direction between an inner diameter-side stepped surface on the outer peripheral surface of the first member and a retaining ring locked on the outer peripheral surface, and a radially outer part of the radial sliding bearing is sandwiched in the axial direction between an outer diameter-side stepped surface on the inner peripheral surface of the second member and a retaining ring locked on the inner peripheral surface.

[0121] In this example, the circumferential width of the first protrusion 18, the circumferential width of the second protrusion 26, the circumferential width of the first intermediate protrusion 38, and the circumferential width of the second intermediate protrusion 39 are all 45 degrees. In an implementation of the present invention, the circumferential width of the first protrusion, the circumferential width of the second protrusion, the circumferential width of the first intermediate protrusion, and the circumferential width of the second intermediate protrusion are not particularly limited and can be freely selected. However, if the circumferential width is excessively small, the strength of the protrusions cannot be sufficiently ensured. Conversely, if the circumferential width is excessively large, the rotation amount of the rotary member becomes excessively small.In consideration of this, the circumferential width of the first projection, the circumferential width of the second projection, the circumferential width of the first intermediate projection, and the circumferential width of the second intermediate projection may be set to 90 degrees or less, and preferably to 30 degrees or more and 60 degrees or less.

[0122] When the circumferential width of the first protrusion, the circumferential width of the second protrusion, the circumferential width of the first intermediate protrusion, and the circumferential width of the second intermediate protrusion are all W [degrees], and the number of intermediate links is n, the rotatable size α [degrees] of the rotary member coupled to and fixed to the first link 14 is as follows: α = (360 - 2W) (n + 1). Therefore, when W is set to 90 degrees or less, and preferably to 30 degrees or more and 60 degrees or less, the number of lock-to-lock turns (approximately 1 to 4,167) of a steering wheel provided in a typical automatic vehicle can be achieved with a minimum number of intermediate links (four or less).

[0123] Furthermore, in implementing the present invention, the circumferential width of the first protrusion, the circumferential width of the second protrusion, the circumferential width of the first intermediate protrusion, and the circumferential width of the second intermediate protrusion are not necessarily all the same, and some or all of them may be different from each other.

[0124] In this example, the first intermediate protrusion 38 and the second intermediate protrusion 39 in the intermediate member 16 are 180 degrees out of phase with each other in the circumferential direction. Therefore, the center of gravity of the intermediate member 16 can be positioned on the center axis O of the intermediate member 16. Thus, even if no torque is applied to the steering shaft 9, rotation of the intermediate member 16 caused by gravity can be prevented. In an implementation of the present invention, the phases of the first intermediate protrusion and the second intermediate protrusion in the circumferential direction can be freely set. Specifically, as in the fourth example of the embodiment, as described below with reference to Fig. 12 and Fig. 13, the phases of the first intermediate protrusion and the second intermediate protrusion may be made coincident with each other in the circumferential direction, or the first intermediate protrusion and the second intermediate protrusion may be arranged out of phase with each other by 90 degrees in the circumferential direction.

[0125] Furthermore, in this example, the first protrusion 18, the second protrusion 26, the first intermediate protrusion 38, and the second intermediate protrusion 39 all have a sector-shaped end surface when viewed from the axial direction. Therefore, a contact area between the first protrusion 18 and the first intermediate protrusion 38 and a contact area between the second protrusion 26 and the second intermediate protrusion 39 are increased, and the contact surface pressure can be kept low. Furthermore, Patent Literature 2 does not describe specific shapes of the engaging parts 13a to 16a and 14b to 17b.

[0126] In this example, the first member 14 is coupled to and fixed to the steering shaft 9, which rotates during use, and the second member 15 is coupled to and fixed to the steering column 8, which does not rotate during use. In one implementation of the present invention, the second member may also be coupled to and fixed to a rotary member that rotates during use, and the first member may be coupled to and fixed to a fixed member that does not rotate during use.

[0127] In an implementation of the invention, no restrictions are imposed on the materials of the first member, the second member, and the intermediate member, as long as they can rotate (slide) relative to each other, and they may be formed of, for example, a synthetic resin or a metal material. The first member, the second member, and the intermediate member are integrally formed or may be formed by combining a plurality of components. When a member is formed by combining a plurality of components, a projection or a portion other than the projection may be formed of a different material. If the first projection and the first intermediate projection are formed of different metal materials, adhesion between the first projection and the intermediate first projection can be prevented.If the second protrusion and the second intermediate protrusion are formed from different metal materials, adhesion between the second protrusion and the second intermediate protrusion can be prevented. And if the protrusion is formed from a synthetic resin, collision noise can be reduced.

[0128] To prevent adhesion and seizure of the first member, the second member, and the intermediate member, it is desirable to fill a cylindrical space between the outer peripheral surface of the first cylindrical part of the first member and the inner peripheral surface of the second cylindrical part of the second member with a lubricant such as grease. An oil seal may be provided by the first cylindrical part of the first member and the second flange part and / or the second cylindrical part of the second member.

[0129] In this example, the rotation limiting device 4 is integrated into the steering unit 3 and forms a steer-by-wire type steering device 1. Alternatively, the rotation limiting device according to the invention can also be integrated into another rotary machine device and used to limit the rotation amount of a rotary member therein. Furthermore, the steering device does not have to be of the steer-by-wire type, but can also be a steering device in which a steering unit and a steered unit are mechanically connected. [Second example of the embodiment]

[0130] Fig. 9 shows a second example of the embodiment of the present invention. In a rotation limiting device 4b according to this example, the intermediate member 16c includes, similarly to the modification of the first example of the embodiment, a side plate portion 37c having a hollow circular plate shape; a first intermediate protrusion 38c projecting to the other axial side from another axial side surface of the side plate portions 37c at a position in the circumferential direction; and a second intermediate protrusion 39c projecting to the one axial side from an axial side surface at a position radially opposite to the first intermediate protrusion 38c. That is, the intermediate member 16c does not include the cylindrical intermediate portion 40 in the intermediate member 16 according to the first example of the embodiment.

[0131] The rotation limiting device 4b of this example includes two annular clearance adjusting members 48. Of the two clearance adjusting members 48, the clearance adjusting member 48 on the other axial side is sandwiched in the axial direction between the radially inner part of one axial side surface (the first side surface 25) of the first flange part 20 of the first member 14 and a radially inner part of another axial side surface of the side plate part 37c. The clearance adjusting member 48 on the one axial side is sandwiched in the axial direction between the radially inner part of one axial side surface of the side plate part 37c and the radially inner part of the other axial side surface (the second side surface 34) of the second flange part 28 of the second member 15.

[0132] Each of the clearance adjustment members 48 is formed by a spacer made of a material having a small friction coefficient with respect to one axial side surface of the first flange portion 20 and the other axial side surface of the second flange portion 28 and / or the side plate portion 37c. Specifically, for example, each of the clearance adjustment members 48 may be formed of a synthetic resin disk, an oil-retaining metal, or the like.

[0133] With the rotation limiting device 4b of this example, the rotational resistance between the first link 14 and the intermediate link 16c and the rotational resistance between the second link 15 and the intermediate link 16c can be prevented from becoming excessively large, and at the same time, rattling of the intermediate link 16c with respect to the first link 14 and the second link 15 in the axial direction can be suppressed. The configurations and operating effects of other parts are the same as those of the first example of the embodiment and the modification thereof. [Third example of the embodiment]

[0134] Fig. 10 and Fig. 11 shows a third example of the embodiment of the present invention. A rotation limiting device 4c according to this example includes the first member 14, the second member 15, and three intermediate members 16c. All the intermediate members 16c have the same shape. In this example, each of the intermediate members 16c includes: the side plate part 37c having a hollow circular plate shape; the first intermediate protrusion 38c protruding to the other axial side from another axial side surface of the side plate parts 37c at a position in the circumferential direction; and the second intermediate protrusion 39c protruding to the one axial side from an axial side surface at a position radially opposite to the first intermediate protrusion 38c.The three intermediate members 16c are arranged in a row in the axial direction and externally fitted to the large-diameter cylindrical surface portion 21 of the first cylindrical portion 19 of the first member 14 in such a way that they can be rotated relative to each other. 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 of the second example of the embodiment by the amount of the two added intermediate members 16c.

[0135] Furthermore, the rotation limiting device 4c of this example includes four clearance adjusting members 48, each in a portion between the three intermediate members 16c, a portion between the intermediate member 16c on the other axial side and the first flange portion 20, and a portion between the intermediate member 16c on the one axial side and the second flange portion 28. As a result, rattling of the three intermediate members 16c with respect to the first member 14 and the second member 15 in the axial direction is prevented. Each of the clearance adjusting members 48 is formed of a material having a small friction coefficient with respect to 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.

[0136] Because the rotation limiting device 4c according to this example comprises three intermediate members 16c, when the circumferential width of the first projection, the circumferential width of the second projection, the circumferential width of the first intermediate projection, and the circumferential width of the second intermediate projection are all 45 degrees, the rotation amount of the steering shaft 9 coupled to and fixed to the first member 14 (see Fig. 1) can be doubled compared to a structure with only one intermediate member 16, such as in the rotation limiting device 4 according to the first example of the embodiment. Specifically, in the rotation limiting device 4c of this example, when the circumferential width W of the first projection 18, the second projection 26, the first intermediate projection 38c, and the second intermediate projection 39c are all 45 degrees, the rotation amount of the steering shaft 9 can be set to 1080 degrees.

[0137] In the rotation limiting device 4c of this example, the three intermediate members 16c have the same shape. Therefore, unnecessary increases in manufacturing costs, parts handling costs, and assembly costs can be avoided, and an increase in the manufacturing cost of the rotation limiting device 4c can be suppressed. The configurations and operating effects of other parts are the same as those of the first example of the embodiment and the modification thereof, as well as the second example of the embodiment. [Fourth example of the embodiment]

[0138] Fig. 12 and Fig.13 shows a fourth example of the embodiment of the present invention. A rotation limiting device 4d of this example includes the first member 14, the second member 15, and three intermediate members 16d. All the intermediate members 16d have the same shape. In this example, each of the intermediate members 16d includes: a side plate part 37d having a hollow circular plate shape; a first intermediate protrusion 38d protruding to the other axial side from another axial side surface of the side plate parts 37d at a position in the circumferential direction; and a second intermediate protrusion 39d protruding to the one axial side from one axial side surface at a position coincident in phase with the first intermediate protrusion 38d with respect to the circumferential direction.The three intermediate members 16d are arranged in series in the axial direction and are externally fitted onto the large-diameter cylindrical surface portion 21 of the first cylindrical portion 19 of the first member 14 such that they can be rotated relative to each other.

[0139] With the rotation limiting device 4d of this example, a large force can be prevented from being applied to the side plate parts 37d of the respective intermediate links 16d in the circumferential direction.

[0140] That is, for example, as in the rotation limiting device 4c of the third example of the embodiment, in a structure in which the phases of the first intermediate protrusion 38c and the second intermediate protrusion 39c are different by 180 degrees in the circumferential direction, a force exerted from the first protrusion 18 to the first intermediate protrusion 38c in the circumferential direction is transmitted in the circumferential direction via the side plate part 37c and exerted from the second intermediate protrusion 39c to the second protrusion 26. Therefore, since a large force may be exerted on the side plate part 37c in the circumferential direction, it is necessary to ensure that the side plate part 37c has sufficient strength.

[0141] Furthermore, in the rotation limiting device 4d of this example, the phases of the first intermediate protrusion 38d and the second intermediate protrusion 39d in the circumferential direction coincide with each other. Therefore, most of the force exerted by the first protrusion 18 on the first intermediate protrusion 38d in the circumferential direction is directly transmitted to the second intermediate protrusion 39d without acting on the side plate part 37d, and is then exerted by the second intermediate protrusion 39d on the second protrusion 26. In this way, a large force can be prevented from acting on the side plate part 37d in the circumferential direction.Therefore, the thickness of the side plate part 37d in the axial direction can be reduced, the first intermediate protrusion 38d and the second intermediate protrusion 39d can be formed of a metal material, and the side plate part 37d can be formed of a synthetic resin, so that the weight of the intermediate member 16d can be more easily reduced. The configurations and operating effects of other parts are the same as those of the first example and the modifications thereto, the second example, and the third example of the embodiment.

[0142] This application is based on Japanese Patent Application (No. 2022-021008) filed on February 15, 2022, the contents of which are incorporated herein by reference. List of reference symbols 1 steering device 2 steering wheel 3 Steering unit 4, 4a, 4b, 4c, 4d Rotation limiting device 5 steered wheels 6 steered unit 7 Control unit 8 Steering column 9 Steering shaft 10 Reaction force application device 11 Gearbox housing 12 Steering actuator 13 Drawbar 14 first link 15 second member 16, 16a, 16b, 16c, 16d pontic 17 Rotating holding mechanism 18 first lead 19 first cylindrical part 20 first flange part 21 large-diameter cylindrical surface part 22 small-diameter cylindrical surface part 23 inner diameter side stepped surface 24 inner diameter locking groove 25 first side surface 26 second lead 27 second cylindrical part 28 second flange part 29 large-diameter cylindrical part 30 small-diameter cylindrical part 31 Connecting plate part 32 outer diameter stepped surface 33 locking groove on the outside diameter side 34 second side surface 35 Earpiece 36 coupling hole 37, 37a, 37b, 37c, 37d side plate part 38, 38a, 38b, 38c, 38d first intermediate projection 39, 39a, 39b, 39c, 39d second intermediate projection 40 cylindrical intermediate part 41 radial roller bearing 42a, 42b retaining ring 43 inner ring 44 Outer ring 45 rolling element 46 inner ring race 47 Outer ring race 48 Distance adjustment element 100 stopper units 101 first rotary link 102 housings 103 second rotary link 104 first turning projection 105 Fixing projection 106 cylindrical part 107 second turning projection QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2020-69844A [0004, 0014] JPH05-042437A

[0014] JP 2021-172231A

[0014] JP 2006-182078A

[0014] US 20220266895

[0014] JP 2022-021008

[0142]

Claims

[1] Rotation limiting device comprising: a first member having a first projection, a second member having a second projection disposed on an axial side relative to the first projection, the second member being disposed around the first member and being configured to rotate relative to the first member, at least one intermediate member arranged between the first member and the second member in a radial direction and held relatively rotatably with respect to the first member and the second member, wherein the at least one intermediate member comprises a side plate part arranged between the first projection and the second projection in an axial direction, a first intermediate projection protruding to another axial side from another axial side surface of the side plate part, and a second intermediate projection protruding to the one axial side from one axial side surface of the side plate part, and a rotational support mechanism configured to support the second link around the first link such that it can be rotated relative to the first link. [2] Rotation limiting device according to claim 1, wherein the first member comprises a first side surface facing the one axial side and the first projection projecting from the first side surface to the one axial side, and wherein the second member comprises a second side surface facing the other axial side and the second projection projecting from the second side surface to the other axial side. [3] Rotation limiting device according to claim 2, wherein the second member comprises a second cylindrical part and a second flange part projecting radially inward from an inner peripheral surface of the second cylindrical part, and wherein the second flange portion has the second side surface on a different axial surface. [4] Rotation limiting device according to claim 2 or 3, wherein the first member comprises a first cylindrical part to which the at least one intermediate member is fitted externally in a relatively rotatable manner, and a first flange part projecting to a radially outer side from an outer peripheral surface of the first cylindrical part, and wherein the first flange portion has the first side surface on an axial side surface. [5] The rotation limiting device according to any one of claims 1 to 4, wherein the rotation holding mechanism comprises a radial rolling bearing having an inner ring externally fitted to the first member, an outer ring fitted to the second member, and a plurality of rolling elements rollably disposed between the inner ring and the outer ring. [6] Steering device comprising: a steering shaft, and a rotation limiting device configured to limit the rotation amount of the steering shaft to a predetermined value, wherein the rotation limiting device is implemented by the rotation limiting device according to one of claims 1 to 5, and wherein the first member or the second member is coupled to and fixed to the steering shaft, and wherein the corresponding other of the first member and the second member is held at and fixed to a part which does not rotate even during use.

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