Rolling bearing device

Abstract

To provide a rolling bearing device capable of restraining water from entering an internal space of a rolling bearing.SOLUTION: A rolling bearing device comprises a housing, an outer ring, an inner shaft, plural rolling elements, a sealing device sealing an annular space between the outer ring and the inner shaft from a first axial side, and a restraining member for restraining the outer ring from moving in the first axial direction. The outer ring has an outer trajectory, a first shoulder extending in the first axial direction from the outer trajectory, an annular groove indented in an outer radial direction from the first shoulder, and a first side face arranged nearer to the first axial side than to the annular groove. The inner shaft has an inner trajectory, a second shoulder extending in the first axial direction from the inner trajectory, a second side face extending in the inner radial direction from the second shoulder and arranged nearer to the second axial face than to the first side face, and a second outer periphery extending in the first axial direction from the second side face. The sealing device includes a seal member mounted to the annular groove and having an axial lip, and a slinger mounted to a second outer periphery of the inner shaft and contacting the axial lip. The slinger is arranged at a position overlaid on the restraining member in the radial direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a rolling bearing device. [Background technology]

[0002] Patent Document 1 discloses an electric power steering device. This electric power steering device includes a rack shaft that applies a steering angle to steered wheels, a pinion shaft that has pinion teeth that mesh with rack teeth of the rack shaft and moves the rack shaft in the axial direction, an electric motor that applies rotational power to the pinion shaft via a reduction gear, and a housing that accommodates the pinion shaft and the reduction gear. The pinion shaft is rotatably supported by the housing via a rolling bearing.

[0003] This rolling bearing comprises an outer ring, an inner ring, a number of rolling elements arranged radially between the outer ring and the inner ring, and a cage that maintains the circumferential spacing of the number of rolling elements. A pair of shield plates, which are sealing members, are provided between both axial ends of the outer ring and both axial ends of the inner ring. The shield plates prevent foreign matter such as dust from entering the internal space of the rolling bearing, and also prevent lubricants such as grease from scattering to the outside. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-289298 A Summary of the Invention [Problem to be solved by the invention]

[0005] When the electric motor and reducer of the electric power steering device described in Patent Document 1 are disposed near the rack shaft, there is a concern that water may get into the housing. If water gets into the reducer from the pinion shaft side that meshes with the rack shaft and the temperature drops, the gears of the reducer may be locked due to freezing or the like, and operation of the gears of the reducer may be hindered. The rolling bearing described in Patent Document 1 is equipped with a shield plate, but it is difficult for this shield plate to prevent water from getting into the internal space of the rolling bearing.

[0006] The present invention has been made in view of the above-mentioned circumstances, and has an object to provide a rolling bearing device that can prevent water from entering the internal space of the rolling bearing. [Means for solving the problem]

[0007] The rolling bearing device of the present disclosure is a housing having an inner circumferential surface; an outer ring having a first outer peripheral surface attached to the inner peripheral surface; an inner shaft disposed radially inside the outer ring; A plurality of rolling elements disposed radially between the outer ring and the inner shaft; a seal device that seals an annular space between the outer ring and the inner shaft from a first axial side; a restricting member that protrudes radially inward from the inner circumferential surface of the housing at a first axial side of the outer ring and restricts movement of the outer ring toward the first axial side, the outer ring has an outer raceway on which the rolling elements roll, a first shoulder extending from the outer raceway to a first side in the axial direction, an annular groove recessed radially outward from the first shoulder, and a first side surface disposed on the first side in the axial direction with respect to the annular groove, the inner shaft has an inner raceway on which the rolling elements roll, a second shoulder extending from the inner raceway to a first axial direction side, a second side surface extending radially inward from the second shoulder and disposed on a second axial direction side of the first side surface, and a second outer circumferential surface extending from the second side surface to the first axial direction side, The seal device includes a seal member attached to the annular groove and having an axial lip, and a slinger attached to the second outer circumferential surface on a first axial side of the seal member with which the axial lip comes into contact, The slinger is disposed at a position radially overlapping with the restricting member. Effect of the Invention

[0008] The rolling bearing device of the present disclosure can prevent water from entering the internal space of the rolling bearing. [Brief description of the drawings]

[0009] [Figure 1] 1 is an overall configuration diagram of an electric power steering device equipped with a rolling bearing device according to a first embodiment. [Diagram 2] FIG. [Diagram 3] FIG. 2 is an enlarged cross-sectional view of the rolling bearing device. [Figure 4] 2 is an enlarged cross-sectional view showing a part of a rolling bearing and a sealing device. FIG. [Diagram 5] FIG. 4 is an enlarged side view showing a slinger and a retaining ring. [Figure 6] FIG. 5 is an enlarged cross-sectional view showing a rolling bearing device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Overview of the embodiment of the present disclosure> Below, an overview of the embodiments of the present disclosure will be listed and described. (1) In an embodiment of the present disclosure, the rolling bearing device a housing having an inner circumferential surface; an outer ring having a first outer peripheral surface attached to the inner peripheral surface; an inner shaft disposed radially inside the outer ring; A plurality of rolling elements disposed radially between the outer ring and the inner shaft; a seal device that seals an annular space between the outer ring and the inner shaft from a first axial side; a restricting member that protrudes radially inward from the inner circumferential surface of the housing at a first axial side of the outer ring and restricts movement of the outer ring toward the first axial side, the outer ring has an outer raceway on which the rolling elements roll, a first shoulder extending from the outer raceway to a first side in the axial direction, an annular groove recessed radially outward from the first shoulder, and a first side surface disposed on the first side in the axial direction with respect to the annular groove, the inner shaft has an inner raceway on which the rolling elements roll, a second shoulder extending from the inner raceway to a first axial direction side, a second side surface extending radially inward from the second shoulder and disposed on a second axial direction side of the first side surface, and a second outer circumferential surface extending from the second side surface to the first axial direction side, The seal device includes a seal member attached to the annular groove and having an axial lip, and a slinger attached to the second outer circumferential surface on a first axial side of the seal member with which the axial lip comes into contact, The slinger is disposed at a position radially overlapping with the restricting member.

[0011] According to the rolling bearing device having the above configuration, the sealing device includes a slinger attached to the inner shaft and a sealing member attached to the outer ring and having an axial lip in contact with the slinger, so that the sealing device can suppress the intrusion of water from the first axial side, thereby improving waterproofing. In addition, the second side surface of the inner shaft is disposed on the second axial side of the first side surface of the outer ring, and the slinger attached to the second outer peripheral surface of the inner shaft is disposed at a position radially overlapping with the regulating member, so that the slinger can be disposed as close as possible to the second axial side (sealing member side), and an increase in the axial dimension of the rolling bearing device can be suppressed. Since the slinger is disposed at a position radially overlapping with the regulating member, the axial distance between the slinger and the sealing member can be shortened, the length of the axial lip can be shortened, and the sealing performance can be improved.

[0012] (2) In the rolling bearing device of (1) above, the restricting member is a retaining ring that is radially contractible, The housing is provided with a second annular groove in which the retaining ring is mounted; The minimum inner diameter of the retaining ring installed in the second annular groove is larger than the outer diameter of the slinger, The minimum inner diameter of the retaining ring when shrunk for installation in the second annular groove is smaller than the outer diameter of the slinger. With this configuration, the slinger of the sealing device can be disposed at a position radially overlapping with the retaining ring mounted in the second annular groove.

[0013] (3) In the rolling bearing device of (1) or (2) above, the inner shaft has a shaft body having the second outer peripheral surface, and an inner ring that is separate from the shaft body, is fixed to the second outer peripheral surface, and has the inner raceway, the second shoulder, and the second side surface.

[0014] <Details of the embodiment of the present disclosure> Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [First embodiment]

[0015] [Electric power steering device configuration] FIG. 1 is an overall configuration diagram of an electric power steering device equipped with a rolling bearing device according to a first embodiment. The electric power steering device 11 is mounted on a vehicle. The electric power steering device 11 steers left and right front wheels 13, which are steered wheels, in response to the operation of a steering wheel 12 by a driver. The electric power steering device 11 includes a steering shaft 14. The steering shaft 14 includes a plurality of shafts connected via universal joints or the like. The steering wheel 12 is connected to one end of the steering shaft 14. The steering shaft 14 rotates in conjunction with the rotation of the steering wheel 12. The other end of the steering shaft 14 is provided with pinion teeth 14a.

[0016] The electric power steering device 11 includes a rack shaft 17. The rack shaft 17 extends in the left-right direction of the vehicle (left-right direction in FIG. 1). One end of the rack shaft 17 is provided with rack teeth 17a. The pinion teeth 14a of the steering shaft 14 and the rack teeth 17a of the rack shaft 17 mesh with each other. The pinion teeth 14a and the rack teeth 17a form a rack-and-pinion mechanism 16. The rack shaft 17 moves left and right as the steering shaft 14 rotates.

[0017] The steerable wheels 13 are connected to both axial ends of the rack shaft 17 via tie rods 18 or the like. The steerable wheels 13 are steered by the left and right movement of the rack shaft 17. The vehicle changes its traveling direction left and right by steering the steerable wheels 13.

[0018] The electric power steering device 11 of this embodiment is a so-called dual pinion type power steering device. The electric power steering device 11 includes a steering assist device 21. The steering assist device 21 generates an assist torque that assists the steering of the steering wheel 12. The steering assist device 21 includes an electric motor 22, a reduction gear mechanism 23, a pinion shaft 24, and a rolling bearing device 25.

[0019] Fig. 2 is a cross-sectional view of the steering assist device. In the following description, a direction parallel to the central axis C of the pinion shaft 24 may be referred to as the "axial direction", a direction perpendicular to the central axis C as the "radial direction", and a circumferential direction about the central axis C as the "circumferential direction". In addition, in the axial direction, the rack shaft 17 side (right side in Fig. 2) may be referred to as the "first axial side", and the reduction mechanism 23 side of the steering assist device 21 (left side in Fig. 2) as the "second axial side".

[0020] The electric motor 22 (see FIG. 1) generates an assist torque in response to a steering torque generated by steering the steering wheel 12. An output shaft of the electric motor 22 is connected to a reduction gear mechanism 232. The reduction gear mechanism 23 reduces the rotation speed of the output shaft of the electric motor 22. As shown in FIG. 2, the reduction gear mechanism 23 has a worm shaft 26 and a worm wheel 27. The worm shaft 26 and the worm wheel 27 have gears that mesh with each other. The worm shaft 26 has a central axis that is perpendicular to the axial direction of the pinion shaft 24. The worm shaft 26 is connected to the output shaft of the electric motor 22 so as to be rotatable integrally therewith. The worm wheel 27 rotates by reducing the rotation transmitted from the worm shaft 26. The worm wheel 27 is disposed concentrically with the pinion shaft 24 and rotates around the central axis C of the pinion shaft 24.

[0021] The pinion shaft 24 is a shaft provided separately from the steering shaft 14. The end portion on the second axial side of the pinion shaft 24 is fixed to the worm wheel 27. For example, the end portion on the second axial side of the pinion shaft 24 is press-fitted into the worm wheel 27. The pinion shaft 24 rotates integrally with the worm wheel 27.

[0022] Pinion teeth 24a are provided on an end portion of the pinion shaft 24 on a first axial side. As shown in Fig. 1, rack teeth 17b are provided on the other end portion of the rack shaft 17. The pinion teeth 24a of the pinion shaft 24 and the rack teeth 17b of the rack shaft 17 mesh with each other. The pinion teeth 24a and the rack teeth 17b form a rack-and-pinion mechanism 28. The rack shaft 17 moves in the left-right direction of the vehicle as the pinion shaft 24 rotates.

[0023] The power (assist torque) output from the electric motor 22 is applied to the rack shaft 17 via the reduction gear mechanism 23 and the rack and pinion mechanism 28. At this time, the rotational motion of the electric motor 22 is converted into linear motion of the rack shaft 17 in the left-right direction of the vehicle. Therefore, the assist torque generated by the steering assist device 21 can be applied to the rack shaft 17 to assist the steering of the steered wheels 13.

[0024] 2, the steering assist device 21 includes a rolling bearing device 25. The rolling bearing device 25 includes a housing 31, a rolling bearing 32, a retaining ring (restricting member) 38, and a sealing device 41. The housing 31 accommodates the reduction gear mechanism 23 and the rack and pinion mechanism 28. Specifically, the housing 31 has a first accommodating portion 31A and a second accommodating portion 31B. The first accommodating portion 31A accommodates the worm shaft 26, the worm wheel 27, and a portion of the pinion shaft 24. The second accommodating portion 31B accommodates another portion of the pinion shaft 24 and a portion of the rack shaft 17. The second accommodating portion 31B may be integral with the rack housing that accommodates the rack shaft 17, or may be separate from it.

[0025] An end portion of the pinion shaft 24 on the second axial side is rotatably supported in the first housing portion 31A via a rolling bearing 32. The rolling bearing 32 in this embodiment is a deep groove ball bearing. The rolling bearing 32 has an outer ring 34, an inner ring 35, rolling elements 36, and a cage 37. The inner ring 35 in this embodiment is integral with the pinion shaft 24 and is a part of the pinion shaft 24. In this specification, the inner ring 35 and the pinion shaft 24 may be collectively referred to as the "inner shaft."

[0026] Fig. 3 is an enlarged cross-sectional view of the rolling bearing device 25. Fig. 4 is an enlarged cross-sectional view of a part of the rolling bearing and the seal device. As shown in FIG. 3, the outer ring 34 has an annular shape. A raceway (outer raceway) 34a is provided on the inner peripheral surface of the outer ring 34. The raceway 34a has a cross-sectional shape of a substantially arc shape. Shoulders 34b and 34c are provided on both sides of the raceway 34a in the axial direction. The shoulders 34b and 34c are cylindrical surfaces parallel to the central axis C (see FIG. 2). Annular grooves 34d and 34e are provided on both sides of each of the shoulders 34b and 34c in the axial direction. A seal member 42 (described later) is attached to the annular groove 34e on the first axial side. As shown in FIG. 4, the annular groove 34e has an inner side surface 34e1 extending radially outward from the shoulder 34c, a bottom surface 34e2 extending from a radial outer end of the inner side surface 34e1 to the first axial side, and an inner side surface 34e3 extending radially inward from an end of the bottom surface 34e2 on the first axial side. The radial length of the inner surface 34e3 is shorter than the radial length of the inner surface 34e1. No seal member is attached to the annular groove 34d. Therefore, the annular groove 34d may be omitted. Alternatively, a seal member may be attached to the annular groove 34d.

[0027] As shown in Fig. 3, an outer peripheral surface 34h of the outer ring 34 is attached to an inner peripheral surface (mounting surface) 31a of the housing 31. The mounting surface 31a is a cylindrical surface parallel to the central axis C (see Fig. 2). The housing 31 has a side surface 31b extending radially inward on the second axial side of the mounting surface 31a. A side surface 34f on the second axial side of the outer ring 34 abuts against the side surface 31b of the housing 31. As a result, the movement of the outer ring 34 toward the second axial side is restricted by the side surface 31b of the housing 31.

[0028] An annular groove 31c is provided in the middle of the inner peripheral surface 31a of the housing 31. As shown in FIG. 4, the annular groove 31c has an inner side surface 31c1 extending radially outward from the inner peripheral surface 31a of the housing 31, a bottom surface 31c2 extending from a radially outer end of the inner side surface 31c1 to a first axial direction side, and an inner side surface 31c3 extending radially inward from an end of the bottom surface 31c2 on the first axial direction side. The inner side surface 31c3 is inclined with respect to an imaginary plane perpendicular to the central axis so that the radially inner end is located closer to the first axial direction side than the radially outer end. A retaining ring 38 is attached to the annular groove 31c.

[0029] The retaining ring 38 protrudes radially inward from the inner peripheral surface 31a of the housing 31. The retaining ring 38 in this embodiment is a C-type retaining ring. A side surface 34g on the first axial side of the outer ring 34 contacts the retaining ring 38. This restricts movement of the outer ring 34 toward the first axial side. Hereinafter, the side surface 34g on the first axial side of the outer ring 34 may be referred to as the "first side surface."

[0030] As shown in FIG. 3, the inner ring 35 is a part of the pinion shaft 24 and is cylindrical. The inner ring 35 is integral with the pinion shaft 24. A raceway (inner raceway) 35a is provided on the outer peripheral surface of the inner ring 35. The raceway 35a has a cross-sectional shape of a substantially arc shape. Shoulders 35b and 35c are provided on both axial sides of the raceway 35a. The shoulders 35b and 35c are cylindrical surfaces parallel to the central axis C (see FIG. 2). Each of the shoulders 35b and 35c substantially constitutes a part of the outer peripheral surface of the pinion shaft 24. The inner ring 35 has a side surface 35d at an end portion on the first axial side. Hereinafter, this side surface 35d may be referred to as a "second side surface." The second side surface 35d is an annular plane substantially perpendicular to the central axis C. The second side surface 35d is disposed on the second axial side of the first side surface 34g of the outer ring 34. In FIG. 3, the axial distance between the first side surface 34g and the second side surface 35d is indicated by the symbol T.

[0031] The pinion shaft 24 has an outer peripheral surface 24b extending from a radially inner end of the second side surface 35d of the inner ring 35 to the first axial side. The outer peripheral surface 24b is a cylindrical surface parallel to the central axis C (see FIG. 2). Hereinafter, the outer peripheral surface 24b may be referred to as the "second outer peripheral surface."

[0032] A plurality of rolling elements 36 are provided at intervals in the circumferential direction. The plurality of rolling elements 36 are disposed between a raceway 34a of the outer ring 34 and a raceway 35a of the inner ring 35, and roll on each of the raceways 34a, 35a. The rolling elements 36 in this embodiment are balls.

[0033] The cage 37 maintains the circumferential spacing of the multiple rolling elements 36. The cage 37 has an annular body 37a that is annular, and multiple tines 37b that protrude from the annular body 37a in the axial direction. The multiple tines 37b are arranged at intervals in the circumferential direction. A space surrounded by the tines 37b and the annular body 37a that are adjacent in the circumferential direction is a pocket that accommodates the rolling elements 36. In this embodiment, the annular body 37a is arranged on the second axial side of the rolling elements 36, and the tines 37b protrude from the annular body 37a toward the first axial side. The annular body 37a may be arranged on the first axial side of the rolling elements 36, and the tines 37b protrude from the annular body 37a toward the second axial side.

[0034] As shown in FIG. 4, the sealing device 41 has a sealing member 42 and a slinger 43. The sealing member 42 has a metal ring 45 and an elastic member 46. The metal ring 45 is made of a metal such as steel or stainless steel. The metal ring 45 has an annular portion 45a. The annular portion 45a is disposed substantially perpendicular to the central axis C (see FIG. 2). The metal ring 45 has a cylindrical portion 45b. The cylindrical portion 45b extends from a radial outer end of the annular portion 45a toward the second axial side. The cylindrical portion 45b has a cylindrical shape parallel to the central axis C (see FIG. 2). The annular portion 45a and the cylindrical portion 45b are integral with each other.

[0035] The elastic member 46 is made of rubber or the like. The elastic member 46 has a first portion 46a, a second portion 46b, a third portion 46c, and a fourth portion 46d. The first portion 46a covers the outer peripheral surface of the cylindrical portion 45b of the metal ring 45. The second portion 46b covers the side surface of the annular portion 45a on the first axial side. The third portion 46c extends radially inward from the second portion 46b. The fourth portion 46d extends obliquely from the radial inner end of the third portion 46c toward the first axial side and radially outward. The fourth portion 46d is an axial lip that contacts the slinger 43.

[0036] The slinger 43 is attached to the outer peripheral surface 24b of the pinion shaft 24 on the first axial side of the seal member 42. The slinger 43 has a cylindrical portion 43a and an annular portion 43b. The cylindrical portion 43a is cylindrical and is fitted and fixed to the outer peripheral surface 24b of the pinion shaft 24. The annular portion 43b is annular and extends radially outward from an end portion of the cylindrical portion 43a on the second axial side. The annular portion 43b is disposed approximately perpendicular to the central axis C (see FIG. 2).

[0037] A side surface 43b1 on the second axial side of the annular portion 43b is a lip contact surface with which the axial lip 46d comes into contact. The axial lip 46d is elastically deformed toward the second axial side by contacting the lip contact surface 43b1, and is pressed against the lip contact surface 43b1 by a restoring force.

[0038] The outer diameter of the slinger 43 (annular portion 43b) is larger than the inner diameter of the seal member 42 and larger than the outer diameter of the shoulder 35c of the inner ring 35. The radially inner end of the seal member 42 is disposed in a space surrounded by the second side surface 35d of the inner ring 35, the outer peripheral surface 24b of the pinion shaft 24, and the seal surface 43b1 of the slinger 43.

[0039] FIG. 5 is an enlarged side view of the slinger and the retaining ring. The retaining ring 38 is a C-shaped retaining ring that is divided in the middle in the circumferential direction. A bulging portion 38a that bulges inward in the radial direction is provided at both ends of the retaining ring 38 located on both sides of the divided portion of the retaining ring 38. The bulging portion 38a is provided with a hole 38b for inserting a tool. The outer diameter of the retaining ring 38 can be contracted by elastic deformation using a tool inserted in the hole 38b.

[0040] 4, the outer diameter of the retaining ring 38 is larger than the inner diameter of the inner peripheral surface 31a of the housing 31. Therefore, by shrinking the outer diameter of the retaining ring 38 so that it is smaller than the inner diameter, the retaining ring 38 can be positioned in the annular groove 31c of the housing 31, and by expanding the outer diameter of the retaining ring 38 by restoring the retaining ring 38 from its shrinkage, the retaining ring 38 can be attached to the annular groove 31c. The retaining ring 38 attached to the annular groove 31c restricts the movement of the outer ring 34 toward the first axial side.

[0041] 4, the slinger 43 of this embodiment is disposed at a position overlapping the retaining ring 38 in the radial direction. Specifically, the annular portion 43b (particularly, the lip contact surface 43b1) of the slinger 43 is disposed at a position overlapping the retaining ring 38 in the radial direction. This arrangement is realized by positioning the second side surface 35d on the first axial side of the inner ring 35 closer to the second axial side than the first side surface 34g on the first axial side of the outer ring 34. This is because the positional relationship between the second side surface 35d and the first side surface 34g makes it possible to move the slinger 43 closer to the second axial side.

[0042] The rolling bearing device 25 of this embodiment is axially compact because the slinger 43 is arranged at a position radially overlapping with the retaining ring 38. In addition, by arranging the slinger 43 at a position radially overlapping with the retaining ring 38, the slinger 43 is arranged axially close to the seal member 42. Therefore, the axial lip 46d of the seal member 42 can be made as short as possible, and high sealing performance is achieved. As a result, in FIG. 2, water is prevented from entering the reduction mechanism 23 side from the first axial side of the rolling bearing 32, and the rolling bearing device 25 of this embodiment can prevent the reduction mechanism 23 from locking due to freezing of water.

[0043] As shown in FIG. 4, when the retaining ring 38 is contracted to be fitted in the annular groove 31c of the housing 31, the smallest inner diameter of the retaining ring 38, i.e., the inner diameter at the position of the bulge 38a shown by the two-dot chain line in FIG. 5, is smaller than the outer diameter of the slinger 43. In contrast, the smallest inner diameter of the retaining ring 38 fitted in the annular groove 31c of the housing 31, i.e., the inner diameter at the position of the bulge 38a shown by the solid line in FIG. 5, is larger than the outer diameter of the slinger 43. Therefore, the slinger 43 can be arranged at a position overlapping the retaining ring 38 in the radial direction. The arrangement of the slinger 43 at a position overlapping the retaining ring 38 in the radial direction is achieved by fitting the slinger 43 to the outer peripheral surface 24b of the pinion shaft 24 after fitting the retaining ring 38 in the annular groove 31c. In this embodiment, the retaining ring 38 attached to the annular groove 31c is in a natural state (no load is applied in the radial direction) where it is not contracted. However, the retaining ring 38 attached to the annular groove 31c may be in a state where it is contracted more than the natural state by contacting its outer circumferential surface with the bottom surface 31c2 of the annular groove 31c.

[0044] In this embodiment, a radial gap is provided between the seal member 42 and the outer peripheral surface 24b of the pinion shaft 24. Also, an axial gap is provided between the seal member 42 and the second side surface 35d of the inner ring 35. However, these gaps are not necessarily required. For example, the seal member 42 may have a radial lip that contacts the outer peripheral surface 24b of the pinion shaft 24, or an axial lip that contacts the second side surface 35d of the inner ring 35.

[0045] [Second embodiment] FIG. 6 is an enlarged cross-sectional view of the rolling bearing device according to the second embodiment. In the rolling bearing device of the first embodiment described above, the inner ring 35 of the rolling bearing 32 is integral with the pinion shaft 24. In the rolling bearing device of the second embodiment, the inner ring 35 of the rolling bearing 32 is configured as a separate body from the pinion shaft 24. The inner ring 35 is attached to the outer circumferential surface 24b of the pinion shaft 24. Specifically, the inner circumferential surface 35e of the inner ring 35 is fitted into the outer circumferential surface 24b of the pinion shaft 24, thereby fixing the inner ring 35 to the pinion shaft 24. In this embodiment, the inner ring 35 and the pinion shaft (shaft main body) 24, which are separate bodies from each other, configure the "inner shaft."

[0046] In this embodiment as well, the second side surface 35d of the inner ring 35 is disposed closer to the second axial direction than the first side surface 34g of the outer ring 34. Moreover, the axial position of the side surface 35f on the second axial direction side of the inner ring 35 coincides with the axial position of the side surface 34f on the second axial direction side of the outer ring 34. However, the relationship between the axial position of the side surface 35f of the inner ring 35 and the axial position of the side surface 34f of the outer ring 34 can be changed as appropriate.

[0047] The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above-described embodiments, and includes the meaning equivalent to the claims and all modifications within the scope thereof.

[0048] In the above embodiment, movement of the outer ring 34 toward the first axial side is limited by the restricting member, the snap ring 38. Instead of this, a restricting member that is integral with the housing 31, for example, the housing 31 may include a stepped surface that extends radially inward from the inner circumferential surface 31a and abuts against the side surface 34g of the outer ring 34 on the first axial side, and the movement of the outer ring 34 toward the first axial side may be limited by this stepped surface.

[0049] In the above embodiment, a portion of the slinger 43 overlaps with the retaining ring 38 in the radial direction, but the entire slinger 43 may overlap with the retaining ring 38 in the radial direction.

[0050] In the above embodiment, the rolling bearing 32 is a deep groove ball bearing. However, the rolling bearing 32 may be an angular ball bearing, a cylindrical roller bearing, or the like. [Explanation of symbols]

[0051] 11: electric power steering device, 24: pinion shaft (shaft body), 24b: second outer peripheral surface, 31: housing, 31a: inner peripheral surface, 31c: second annular groove, 32: rolling bearing, 34: outer ring, 34a: raceway, 34c: shoulder, 34e: annular groove, 34g: first side surface, 34h: first outer peripheral surface, 35: inner ring, 35a: raceway, 35c: shoulder, 35d: second side surface, 36: rolling element, 38: retaining ring (regulating member), 41: sealing device, 42: sealing member, 43: slinger, 46d: axial lip

Claims

1. a housing having an inner circumferential surface; an outer ring having a first outer peripheral surface attached to the inner peripheral surface; an inner shaft disposed radially inside the outer ring; A plurality of rolling elements disposed radially between the outer ring and the inner shaft; a seal device that seals an annular space between the outer ring and the inner shaft from a first axial side; a restricting member that protrudes radially inward from the inner circumferential surface of the housing at a first axial side of the outer ring and restricts movement of the outer ring toward the first axial side, the outer ring has an outer raceway on which the rolling elements roll, a first shoulder extending from the outer raceway to a first side in the axial direction, an annular groove recessed radially outward from the first shoulder, and a first side surface disposed on the first side in the axial direction with respect to the annular groove, the inner shaft has an inner raceway on which the rolling elements roll, a second shoulder extending from the inner raceway to a first side in the axial direction, a second side surface extending radially inward from the second shoulder and disposed on a second side in the axial direction relative to the first side surface, and a second outer circumferential surface extending from the second side surface to the first side in the axial direction, The seal device includes a seal member attached to the annular groove and having an axial lip, and a slinger attached to the second outer circumferential surface on a first axial side of the seal member and in contact with the axial lip, The slinger is disposed at a position radially overlapping with the regulating member.

2. The restricting member is a retaining ring that is radially contractible, The housing includes a second annular groove in which the retaining ring is mounted; The minimum inner diameter of the retaining ring installed in the second annular groove is larger than the outer diameter of the slinger, 2. The rolling bearing device according to claim 1, wherein a minimum inner diameter of the retaining ring when shrunk for installation in the second annular groove is smaller than an outer diameter of the slinger.

3. 3. The rolling bearing device according to claim 1, wherein the inner shaft comprises: a shaft body having the second outer peripheral surface; and an inner ring that is separate from the shaft body, is fixed to the second outer peripheral surface, and has the inner raceway, the second shoulder, and the second side surface.

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