Rolling bearing device for vehicle wheels and tapered roller bearing

Abstract

A rolling bearing device (10) for a wheel has an inner member (12), an outer member (11), a plurality of tapered rollers (13), and a ring-shaped cage (14). The cage (14) has a small-diameter annular portion (41), a large-diameter annular portion (42), and a plurality of columns (43). The columns (43) have a contact surface (45) on a side surface (44) thereof on the small-diameter annular portion (41) side and a non-contact surface (46) on the large-diameter annular portion (42) side. The contact surface (45) is capable of contacting an outer peripheral surface (131) of the tapered roller (13). The non-contact surface (46) is located at a position further from the tapered roller (13) in the bearing circumferential direction than the contact surface (45), and does not contact the outer peripheral surface (131) of the tapered roller (13).

Description

Technical Field

[0001] This invention relates to rolling bearing devices for wheels and tapered roller bearings. Background Technology

[0002] Patent Document 1 discloses a rolling bearing device for a car wheel. The rolling bearing device for the wheel includes an outer member mounted on the car body, an inner member having a flange for mounting the wheel, tapered rollers as multiple rolling elements disposed between the outer member and the inner member, and an annular retainer for holding the multiple tapered rollers.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-10304 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] When a car is moving, if the inner component rotates along with the wheel, multiple tapered rollers will rotate on their own axis and revolve around the outer component. At this time, a torque as rotational resistance is generated between the tapered rollers and the cage. The main reasons for this torque can be summarized in the following three points.

[0008] (1) Sliding resistance caused by the contact between the outer circumferential surface of the tapered roller and the columns of the cage.

[0009] (2) Sliding friction resistance between the end face of the tapered roller and the annular portion of the cage.

[0010] (3) Resistance generated by the conical roller agitator for grease (agitation resistance)

[0011] The torque causes rotational losses, so it is desirable to minimize them as much as possible.

[0012] Therefore, the purpose of this disclosure is to provide a rolling bearing device and tapered roller bearing for wheels that can reduce torque as a rotational resistance.

[0013] Technical solutions to solve technical problems

[0014] The wheel rolling bearing device according to the embodiments of the present invention includes an inner square member, an outer square member, a plurality of tapered rollers disposed between the inner square member and the outer square member, and an annular cage for holding the plurality of tapered rollers. One of the inner square member and the outer square member has a flange for wheel mounting, and the other of the inner square member and the outer square member is mounted on the vehicle body. The cage has a small-diameter annular portion, a large-diameter annular portion with a diameter larger than the small-diameter annular portion, and a plurality of posts connecting the small-diameter annular portion and the large-diameter annular portion. The posts have a contact surface on the side of the post located on the side of the small-diameter annular portion and a non-contact surface located on the side of the large-diameter annular portion. The contact surface can contact the outer peripheral surface of the tapered roller, and the non-contact surface is located at a position further away from the tapered roller in the bearing circumferential direction than the contact surface and does not contact the outer peripheral surface of the tapered roller.

[0015] The tapered roller bearing according to the embodiments of the present invention has an inner ring, an outer ring, a plurality of tapered rollers disposed between the inner ring and the outer ring, and an annular cage for holding the tapered rollers. The cage has a small-diameter annular portion, a large-diameter annular portion with a diameter larger than the small-diameter annular portion, and a plurality of posts connecting the small-diameter annular portion and the large-diameter annular portion. The posts have a contact surface on the side of the post located on the side of the small-diameter annular portion and a non-contact surface located on the side of the large-diameter annular portion. The contact surface can contact the outer peripheral surface of the tapered roller, and the non-contact surface is located at a position further away from the tapered roller in the bearing circumferential direction than the contact surface and does not contact the outer peripheral surface of the tapered roller.

[0016] The effects of the invention

[0017] The rolling bearing device and tapered roller bearing for wheels according to embodiments of the present invention can reduce torque as a rotational resistance. Attached Figure Description

[0018] [ Figure 1 ] Figure 1 This is a cross-sectional view showing an example of the rolling bearing device for wheels according to the present invention.

[0019] [ Figure 2 ] Figure 2 It is a three-dimensional diagram of the cage.

[0020] [ Figure 3 ] Figure 3 It is a three-dimensional diagram of the cage.

[0021] [ Figure 4 ] Figure 4 This is an enlarged view showing a portion of the cage.

[0022] [ Figure 5 ] Figure 5 This is an enlarged view showing a portion of the cage.

[0023] [ Figure 6 ] Figure 6 This is an illustrative diagram showing a portion of the cage viewed from the radially outer side.

[0024] [ Figure 7 ] Figure 7 It is a cross-sectional view showing a part of the rolling bearing assembly for wheels. Detailed Implementation

[0025] <Summary of Embodiments of the Invention>

[0026] Hereinafter, a summary of embodiments of the present invention is listed and described.

[0027] (1) The wheel rolling bearing device according to the embodiments of the present invention has an inner square member, an outer square member, a plurality of tapered rollers disposed between the inner square member and the outer square member, and an annular cage for holding the plurality of tapered rollers. One of the inner square member and the outer square member has a flange for mounting a wheel, and the other of the inner square member and the outer square member is mounted on a vehicle body. The cage has a small-diameter annular portion, a large-diameter annular portion with a diameter larger than the small-diameter annular portion, and a plurality of posts connecting the small-diameter annular portion and the large-diameter annular portion. The posts have a contact surface on the side of the post located on the side of the small-diameter annular portion and a non-contact surface located on the side of the large-diameter annular portion. The contact surface can contact the outer peripheral surface of the tapered roller, and the non-contact surface is located at a position further away from the tapered roller in the bearing circumferential direction than the contact surface and does not contact the outer peripheral surface of the tapered roller.

[0028] The wheel rolling bearing assembly has tapered rollers as rolling elements. When the rolling element is a tapered roller, the circumferential speed on the outer circumferential surface caused by its rotation is smaller on the smaller diameter annular side than on the larger diameter annular side.

[0029] According to the cage, the tapered roller is guided by contact on the contact surface located on the side of the smaller diameter annular portion with lower circumferential speed, but not by contact on the non-contact surface located on the side of the larger diameter annular portion with higher circumferential speed.

[0030] Due to the presence of non-contact surfaces, the contact area between the side of the roller and the outer circumferential surface of the tapered roller is narrowed, and because the circumferential velocity of the contact portion is relatively small, the sliding resistance between the tapered roller and the roller of the cage is reduced. As a result, the torque, which is a rotational resistance, is reduced.

[0031] (2) Preferably, the large-diameter annular portion has: an annular large-diameter main body portion that is continuous in the circumferential direction of the bearing; and a plurality of plate portions that extend from the large-diameter main body portion inward in the radial direction of the bearing and are opposite to the large end face of the tapered roller, and are intermittently arranged in the circumferential direction of the bearing.

[0032] Grease present in the pockets of the cage can sometimes contribute to increased stirring resistance caused by the tapered rollers. Therefore, according to the aforementioned structure, grease that has entered the pockets can easily flow out between the multiple plates. As a result, the increase in grease stirring resistance can be suppressed.

[0033] (3) Preferably, in the wheel rolling bearing device of (2), the small-diameter annular portion has a first protrusion that contacts the small end face of the tapered roller, and the plate portion has a second protrusion that contacts the large end face of the tapered roller. The first protrusion can contact at the intersection of the small end face and the rotation center line of the tapered roller, and the second protrusion can contact at the intersection of the large end face and the rotation center line of the tapered roller.

[0034] According to the structure described, the small end face of the tapered roller contacts the first protrusion of the small-diameter annular portion, thereby reducing the contact area. The large end face of the tapered roller contacts the second protrusion of the plate portion of the large-diameter annular portion, thereby reducing the contact area. As a result, the sliding friction resistance between the tapered roller and the small-diameter and large-diameter annular portions is reduced.

[0035] (4) Preferably, in the wheel rolling bearing device of (1), the small-diameter annular portion has a first protrusion that contacts the small end face of the tapered roller, and the large-diameter annular portion has a second protrusion that contacts the large end face of the tapered roller. The first protrusion can contact at the intersection of the small end face and the rotation center line of the tapered roller, and the second protrusion can contact at the intersection of the large end face and the rotation center line of the tapered roller.

[0036] According to the structure described, the small end face of the tapered roller contacts the first protrusion of the small-diameter annular portion, thereby reducing the contact area. Similarly, the large end face of the tapered roller contacts the second protrusion of the large-diameter annular portion, further reducing the contact area. As a result, the sliding friction resistance between the tapered roller and both the small-diameter and large-diameter annular portions is reduced.

[0037] (5) Preferably, in the wheel rolling bearing device of any one of (1) to (4), the small diameter annular portion has: a small diameter main body portion connected to the column; and an extension portion extending radially inward from the small diameter main body portion and opposite to the small end face of the tapered roller, the extension portion extending to a position further radially inward than the rotation center line of the tapered roller.

[0038] External grease is less likely to enter the cage pockets due to the extension. As a result, the increase in grease stirring resistance can be suppressed.

[0039] (6) Preferably, in the wheel rolling bearing device of (5), the extension has a first protrusion that contacts the small end face of the tapered roller, and the large diameter annular portion has a second protrusion that contacts the large end face of the tapered roller. The first protrusion can contact at the intersection of the small end face and the rotation center line of the tapered roller, and the second protrusion can contact at the intersection of the large end face and the rotation center line of the tapered roller.

[0040] According to the structure described, the small end face of the tapered roller contacts the first protrusion of the extension portion of the small-diameter annular portion, thereby reducing the contact area. The large end face of the tapered roller contacts the second protrusion of the large-diameter annular portion, thereby reducing the contact area. As a result, the sliding friction resistance between the tapered roller and the small-diameter and large-diameter annular portions is reduced.

[0041] (7) Preferably, in the rolling bearing device for a wheel of any one of (1) to (6), the column has: a first column portion having the contact surface and extending from the small-diameter annular portion; and a second column portion having the non-contact surface and connecting the first column portion and the large-diameter annular portion, wherein the width dimension of the radially outer side of the first column portion is constant along the length direction of the column, or gradually increases toward the second column portion.

[0042] On the large-diameter annular side of the column, a defect exists due to the second column portion having a non-contact surface, forming a shape separate from the tapered roller. Since the radially outer surface of the first column portion has the aforementioned width dimension, there is no defect on the small-diameter annular side of the column. Therefore, grease is less likely to enter the cage pocket from the small-diameter annular side. This suppresses the increase in grease stirring resistance caused by the tapered roller.

[0043] (8) Preferably, in the wheel rolling bearing device of any one of (1) to (7), the column has: a first column portion having the contact surface and extending from the small-diameter annular portion; and a second column portion having the non-contact surface and connecting the first column portion and the large-diameter annular portion, wherein the bearing radial dimension of the second column portion is smaller than that of the first column portion.

[0044] According to the structure, the second column has a smaller circumferential dimension than the first column due to the non-contact surface, and the second column also has a smaller radial dimension than the first column. The non-contact surface becomes narrower compared to the contact surface. Therefore, even if the cage orientation changes, a structure can be obtained in which the tapered roller reliably does not contact the non-contact surface.

[0045] (9) The tapered roller bearing according to the embodiments of the present invention has an inner ring, an outer ring, a plurality of tapered rollers disposed between the inner ring and the outer ring, and an annular cage for holding the tapered rollers. The cage has a small-diameter annular portion, a large-diameter annular portion with a diameter larger than the small-diameter annular portion, and a plurality of posts connecting the small-diameter annular portion and the large-diameter annular portion. The posts have a contact surface on the side of the post located on the side of the small-diameter annular portion and a non-contact surface located on the side of the large-diameter annular portion. The contact surface can contact the outer peripheral surface of the tapered rollers, and the non-contact surface is located at a position further away from the tapered rollers in the bearing circumferential direction than the contact surface and does not contact the outer peripheral surface of the tapered rollers.

[0046] Tapered roller bearings have tapered rollers as rolling elements. In the case of tapered rollers, the circumferential speed on the outer circumferential surface caused by their rotation is smaller on the small diameter annular side than on the large diameter annular side.

[0047] According to the cage, the tapered roller is guided by contact on the contact surface located on the side of the smaller diameter annular portion with lower circumferential speed, but not by contact on the non-contact surface located on the side of the larger diameter annular portion with higher circumferential speed.

[0048] Due to the presence of non-contact surfaces, the contact area between the side of the roller and the outer circumferential surface of the tapered roller is narrowed, and because the circumferential speed of the contact portion is lower, the sliding resistance between the tapered roller and the roller of the cage is reduced. As a result, the torque, which is a rotational resistance, is reduced.

[0049] <Detailed Description of Embodiments of the Invention>

[0050] The embodiments of the present invention will be described below.

[0051] Figure 1 This is a cross-sectional view showing an example of the rolling bearing device for wheels according to the present invention. Figure 1The wheel rolling bearing assembly 10 shown (hereinafter referred to as "bearing assembly 10") is a wheel bearing assembly for automobiles, also known as a wheel hub unit. The bearing assembly 10 is mounted on the suspension system provided on the automobile body and rotatably supports the wheel 7 and the brake disc (not shown) of the braking system.

[0052] The bearing assembly 10 has an outer cylindrical member 11, an inner member 12 having a portion located radially outward therefrom, tapered rollers 13 consisting of two rows of multiple rolling elements disposed between the outer member 11 and the inner member 12, and an annular cage 14 holding the multiple tapered rollers 13. When the bearing assembly 10 is not under load, the central axis of the outer member 11 coincides with the central axis of the inner member 12. These central axes are the central axis C of the bearing assembly 10. Figure 1 It is a sectional view of the plane containing the central axis C.

[0053] Regarding the bearing assembly 10 of this disclosure, various directions are defined. The direction along the central axis C of the bearing assembly 10 is the "axial direction" of the bearing assembly 10. This axial direction also includes directions parallel to the central axis C. In the bearing assembly 10, the axial side ( Figure 1 The left side) is the outer side of the vehicle, and the opposite axis is the other side ( Figure 1 The right side of the vehicle is the inner side. The direction orthogonal to the central axis C is the "radial" direction of the bearing assembly 10. The direction along the circle centered on the central axis C is the "circumferential" direction of the bearing assembly 10.

[0054] The circumferential direction of the bearing assembly 10 is referred to as the "bearing circumferential direction". When the central axis of the cage 14 is aligned with the central axis C of the bearing assembly 10, the circumferential direction of the cage 14 is aligned with the bearing circumferential direction.

[0055] The radial direction of the bearing assembly 10 is referred to as the "bearing radial direction". When the central axis of the cage 14 is aligned with the central axis C of the bearing assembly 10, the radial direction of the cage 14 is aligned with the bearing radial direction.

[0056] The outer member 11 has a fixing flange 21 on its outer periphery that is fixed to a portion of the suspension assembly (not shown). The outer member 11 has a first outer raceway surface 221 and a second outer raceway surface 222 on its inner periphery.

[0057] The inner member 12 has an inner shaft 31 and an annular inner ring 32 mounted on the inner side of the vehicle. The inner shaft 31 has a shaft body 33 and a flange 34 for mounting wheels 7, etc. The flange 34 extends radially outward from the end 331 on the outer side of the shaft body 33. The inner ring 32 is fixed to the portion 332 on the inner side of the shaft body 33 with an interference fit.

[0058] The inner ring 32 has a first inner raceway surface 321 on its outer periphery. The inner shaft 31 has a second inner raceway surface 322 on its outer periphery.

[0059] The tapered roller 13 on the inner side of the vehicle is disposed in a rotatable manner between the first outer raceway surface 221 and the first inner raceway surface 321. The tapered roller 13 on the outer side of the vehicle is disposed in a rotatable manner between the second outer raceway surface 222 and the second inner raceway surface 322.

[0060] The tapered rollers 13 on the inner side of the vehicle are held by a first retainer 14, and the tapered rollers 13 on the outer side of the vehicle are held by a second retainer 14. The first retainer 14 and the second retainer 14 are arranged in opposite directions along the axis, but the structure of the first retainer 14 is the same as that of the second retainer 14.

[0061] [Regarding cage 14]

[0062] Figure 2 and Figure 3 This is a three-dimensional view of cage 14. Figure 4 and Figure 5 This is an enlarged view showing a portion of the cage 14. Figure 6 This is an explanatory diagram showing a portion of the cage 14 viewed from the radially outer side. The cage 14 has a small-diameter annular portion 41, a large-diameter annular portion 42, and a plurality of posts 43. The diameter of the large-diameter annular portion 42 is larger than that of the small-diameter annular portion 41. The posts 43 connect the small-diameter annular portion 41 and the large-diameter annular portion 42. The space formed between the small-diameter annular portion 41 and the large-diameter annular portion 42 and between two adjacent posts 43 in the circumferential direction of the cage 14 forms a pocket 15 for accommodating a tapered roller 13.

[0063] In the case of a bearing portion having tapered rollers 13, when the bearing portion rotates, under the influence of centrifugal force, the grease and the base oil of the grease flow from one direction of the bearing portion to the other. One direction of the bearing portion's axial direction is the side of the small-diameter annular portion 41 and its outer bearing side, and the other direction of the bearing portion's axial direction is the side of the large-diameter annular portion 42 and its outer bearing side.

[0064] All columns 43 have the same shape. Each column 43 has a first column portion 431 and a second column portion 432. The first column portion 431 is the part of the column 43 that extends from the small-diameter annular portion 41. The second column portion 432 is the part of the column 43 that connects the first column portion 431 and the large-diameter annular portion 42.

[0065] like Figure 4 and Figure 5As shown, each post 43 has a contact surface 45 on the side 44 of the post 43, located on the side of the small-diameter annular portion 41, and a non-contact surface 46 on the side of the large-diameter annular portion 42. The first post portion 431 has the contact surface 45, and the second post portion 432 has the non-contact surface 46.

[0066] like Figure 6 As shown, the contact surface 45 is the surface that can contact the outer peripheral surface 131 of the tapered roller 13. The non-contact surface 46 is the surface that does not contact the outer peripheral surface 131 of the tapered roller 13. The non-contact surface 46 is located further away from the tapered roller 13 in the bearing circumferential direction than the contact surface 45, and the tapered roller 13 cannot contact the non-contact surface 46.

[0067] A gap is provided between the outer peripheral surface 131 of the tapered roller 13 and the side surface 44 of the post 43. When the bearing assembly 10 rotates, the tapered roller 13 can be displaced relative to the post 43 in the circumferential direction of the bearing within the pocket 15. When the tapered roller 13 housed in the pocket 15 approaches one of the posts 43, the outer peripheral surface 131 of the tapered roller 13 contacts the contact surface 45 of that post 43, but does not contact the non-contact surface 46 of that post 43. The tapered roller 13 is guided by the contact surface 45, not by the non-contact surface 46.

[0068] Furthermore, the cage 14 is guided by the tapered roller 13 through contact surface 45 with the outer peripheral surface 131 of the tapered roller 13. This constitutes a bearing portion in which the cage 14 is guided by rolling elements.

[0069] The contact surface 45 is continuous with the small-diameter annular portion 41. The non-contact surface 46 is continuous with the large-diameter annular portion 42. The non-contact surface 46 is located adjacent to the contact surface 45.

[0070] Figure 7 It indicates a part of the bearing assembly 10 ( Figure 1 The bearing assembly 10 shown is a cross-sectional view of the bearing portion inside the vehicle. The radial dimension of the bearing in the second column portion 432 is smaller than that in the first column portion 431. The side surface of the first column portion 431 is a contact surface 45, and the side surface of the second column portion 432 is a non-contact surface 46. The radial dimension of the bearing in the non-contact surface 46 is smaller than that in the contact surface 45. The contact surface 45 and the non-contact surface 46 are each composed of a plane. A stepped surface 47 is formed between the contact surface 45 and the non-contact surface 46, opposite to the large-diameter annular portion 42.

[0071] like Figure 6 As shown, the second column portion 432 has a smaller circumferential dimension than the first column portion 431 due to the non-contact surface 46. Figure 7As shown, the bearing radial dimension of the second column portion 432 is smaller than that of the first column portion 431. The non-contact surface 46 (second column portion 432) is shorter than the contact surface 45 (first column portion 431) along the length of the column 43. Alternatively, the non-contact surface 46 (second column portion 432) and the contact surface 45 (first column portion 431) may have the same dimension along the length of the column 43. The non-contact surface 46 is narrower than the contact surface 45. Therefore, even if the orientation of the cage 14 changes, a structure can be obtained in which the tapered roller 13 reliably does not contact the non-contact surface 46.

[0072] Alternatively, the non-contact surface 46 (second column 432) may be longer than the contact surface 45 (first column 431) along the length of the column 43.

[0073] The first column portion 431 has a first radially outer surface 48 on the side of the outer member 11. The second column portion 432 has a second radially outer surface 49 on the side of the outer member 11. The first radially outer surface 48 and the second radially outer surface 49 are located on the same plane, and the radially outer surface of the column 43 is straight along the length direction of the column 43.

[0074] like Figure 5 and Figure 6 As shown, the width B1 of the first radially outer surface 48 is constant along the length of the column 43. Alternatively, the width B1 of the first radially outer surface 48 may gradually increase toward the second column portion 432.

[0075] The bearing circumferential edges of the first radial outer surface 48 are straight along the length of the column 43, and the bearing circumferential edges of the second radial outer surface 49 are straight along the length of the column 43.

[0076] like Figure 4 and Figure 5 As shown, on the side of the large-diameter annular portion 42 in the column 43, there is a defect 55 formed in a shape that is separate from the conical roller 13 due to the second column portion 432 having a non-contact surface 46.

[0077] For this, contact surface 45 (refer to) Figure 5 The surface 413 is continuous with the pocket surface 413 of the small diameter annular portion 41. Since the radial outer surface 48 of the first column portion 431 has the width dimension B1, there is no defect on the side of the small diameter annular portion 41 in the column 43.

[0078] Therefore, grease is less likely to enter the pocket 15 of the cage 14 from the small diameter annular portion 41 side.

[0079] If grease remains in the pocket 15, the tapered rollers 13 will agitate the grease when the bearing assembly 10 rotates, generating agitation resistance. Since there are no defects on the side of the small-diameter annular portion 41 in the column 43, grease intrusion into the pocket 15 can be suppressed, and the increase in agitation resistance of the grease caused by the tapered rollers 13 can be suppressed.

[0080] like Figure 4 and Figure 5 As shown, the large-diameter annular portion 42 has an annular large-diameter main body portion 421 and a plurality of plate portions 422. The large-diameter main body portion 421 is a continuous annular portion in the circumferential direction of the bearing. The plate portions 422 extend radially inward from the large-diameter main body portion 421 toward the bearing (towards the inner member 12). The plate portions 422 are intermittently arranged in the circumferential direction of the bearing. That is, the plate portions 422 are arranged at intervals (equal intervals) in the circumferential direction of the bearing. The plate portions 422 are disposed on the large end face 132 of the tapered roller 13 (see reference). Figure 7 (Relative position)

[0081] Plate 422 (refer to Figure 4 The portion not located in the large-diameter annular portion 42 connected to the post 43, but rather at the position corresponding to the pocket 15 (the position opposite to the tapered roller 13). For example... Figure 4 and Figure 5 As shown, a flow path 57 that becomes an opening is provided between two adjacent plate portions 422 in the circumferential direction of the bearing.

[0082] As described above, the grease present in the pocket 15 can sometimes cause an increase in stirring resistance due to the tapered rollers 13. In this embodiment, a flow path 57 is provided between two adjacent plate portions 422. Therefore, the grease that has entered the pocket 15 can easily flow out between the two plate portions 422. As a result, the increase in grease stirring resistance can be suppressed.

[0083] Plate portion 422 extends to the rotation center line Cr of tapered roller 13 (see reference). Figure 7 The plate portion 422 is located further radially inward of the bearing (towards the inner member 12 and the inner ring 32). In this embodiment, the end portion 422a of the plate portion 422 extends to a position further radially inward of the bearing than the rotation center line Cr. The radially inner surface 422c of the plate portion 422 is formed as an inclined surface that slopes toward the outer member 11 as it moves away from the tapered roller 13. The cage 14 is made of resin and is formed by injection molding. The inclined surface (radially inner surface 422c) facilitates demolding during injection molding and does not obstruct the flow of grease from the pocket 15.

[0084] The small-diameter annular portion 41 has a small-diameter main body portion 411 and an extension portion 412. Figure 7In the diagram, the boundary line between the small-diameter main body portion 411 and the extension portion 412 is represented by a double-dotted line. The small-diameter main body portion 411 and the extension portion 412 are continuous in the circumferential direction and are ring-shaped. The small-diameter main body portion 411 is the part of the small-diameter ring portion 41 that is connected to the column 43. The small-diameter main body portion 411 is the part of the small-diameter ring portion 41 located on the side of the outer member 11.

[0085] The extension portion 412 is the part of the small-diameter annular portion 41 located on the side of the inner square member 12 (inner ring 32 side). The extension portion 412 is a portion that extends radially inward from the small-diameter main body portion 411 towards the bearing (inner square member 12, inner ring 32 side). The extension portion 412 has an inner surface 412a opposite to the small end face 133 of the tapered roller 13. This inner surface 412a is annular and is a surface continuous with the pocket surface 413.

[0086] The extension 412 extends to the rotation center line Cr of the tapered roller 13 (see reference). Figure 7 The extension 412 is located further radially inward of the bearing (on the side of the inner member 12 and the inner ring 32). The inner circumferential surface 412b of the extension 412 is close to the shoulder 37 on the small diameter side of the inner member 12 (inner ring 32). A small gap K1 is provided between the extension 412 and the shoulder 37.

[0087] Therefore, external grease is less likely to enter the pocket 15 of the retainer 14 due to the extension 412. As a result, the increase in grease stirring resistance can be suppressed.

[0088] The gap K2 between the end 422a of the plate portion 422 and the shoulder 38 on the large-diameter side of the inner square member 12 (inner ring 32) is larger than the small gap K1 (K2 > K1). The small gap K1 makes it difficult for grease to enter the pocket 15, while the larger gap K2 makes it easy for grease in the pocket 15 to flow out. That is, grease is less likely to remain in the pocket 15.

[0089] Small diameter annular portion 41 (refer to) Figure 3 , Figure 5 It has a first protrusion 51 that contacts the small end face 133 of the tapered roller 13. Large-diameter annular portion 42 (see reference) Figure 2 , Figure 4 It has a second protrusion 52 that contacts the large end face 132 of the tapered roller 13.

[0090] The first protrusion 51 and the second protrusion 52 are described in detail. The first protrusion 51 (refer to...) Figure 7 The second protrusion 52 is provided on the extension 412 in the small-diameter annular portion 41. The second protrusion 52 is provided on the plate portion 422 in the large-diameter annular portion 42.

[0091] A first protrusion 51 is provided on the inner surface 412a of the extension 412 and protrudes from the inner surface 412a. The first protrusion 51 has a shape that follows an imaginary spherical surface. In this embodiment, the first protrusion 51 has a generally hemispherical shape (see reference). Figure 5 The small end face 133 of the tapered roller 13 contacts a portion of the spherical surface of the first protrusion 51. That is, the first protrusion 51 makes point contact with the small end face 133. The first protrusion 51 can be in contact with the small end face 133 and the rotation center line Cr of the tapered roller 13 (refer to...). Figure 7 The two protrusions (51 and 133) make contact at the intersection point Q1. Intersection point Q1 is the location where the calculated circumferential velocity is zero. Therefore, the sliding friction resistance between the first protrusion 51 and the small end face 133 decreases.

[0092] A second protrusion 52 is provided on the inner surface 422b of the plate portion 422 and protrudes from the inner surface 422b. The second protrusion 52 has a shape that follows an imaginary spherical surface. In this embodiment, the second protrusion 52 has a roughly 1 / 4 spherical shape (see reference). Figure 4 The large end face 132 of the tapered roller 13 contacts a portion of the spherical surface of the second protrusion 52. That is, the second protrusion 52 makes point contact with the large end face 132. The second protrusion 52 is able to contact the large end face 132 at the rotational center line Cr of the tapered roller 13 (refer to...). Figure 7 The two protrusions (52 and 132) make contact at the intersection point Q2. Intersection point Q2 is the location where the calculated circumferential velocity is zero. Therefore, the sliding friction resistance between the second protrusion 52 and the large end face 132 decreases.

[0093] [Regarding the bearing device 10 in this embodiment]

[0094] As described above, the bearing device 10 of this embodiment (refer to...) Figure 1 It has an inner square member 12, an outer square member 11, a plurality of tapered rollers 13 disposed between the inner square member 12 and the outer square member 11, and an annular retainer 14 for holding the plurality of tapered rollers 13.

[0095] Cage 14 (refer to) Figure 2 and Figure 3 It has a small-diameter annular portion 41, a large-diameter annular portion 42, and a plurality of pillars 43 connecting the small-diameter annular portion 41 and the large-diameter annular portion 42. Pillars 43 (see reference) Figure 4 and Figure 5 The pillar 43 has a contact surface 45 on the side 44 of the small-diameter annular portion 41 and a non-contact surface 46 on the side of the large-diameter annular portion 42. The contact surface 45 can contact the outer peripheral surface 131 of the tapered roller 13. The non-contact surface 46 is located further away from the tapered roller 13 in the bearing circumferential direction than the contact surface 45 and does not contact the outer peripheral surface 131 of the tapered roller 13.

[0096] The bearing assembly 10 has tapered rollers 13 as rolling elements. When the rolling element is a tapered roller 13, the circumferential speed on its outer circumferential surface 131 caused by its rotation is smaller on the side of the small-diameter annular portion 41 than on the side of the large-diameter annular portion 42. According to the cage 14 of this embodiment, the tapered roller 13 is guided by contact with the contact surface 45 on the side of the small-diameter annular portion 41 where the circumferential speed is smaller, but is not guided by contact with the non-contact surface 46 on the side of the large-diameter annular portion 42 where the circumferential speed is larger.

[0097] Due to the presence of the non-contact surface 46, the contact area between the side surface 44 of the post 43 and the outer peripheral surface 131 of the tapered roller 13 is narrowed, and because the circumferential speed of the contact portion is relatively small, the sliding resistance between the tapered roller 13 and the post 43 of the cage 14 can be reduced. As a result, the torque, which is a rotational resistance, is reduced.

[0098] The small-diameter annular portion 41 has a first protrusion 51 that contacts the small end face 133 of the tapered roller 13. The large-diameter annular portion 42 has a second protrusion 52 that contacts the large end face 132 of the tapered roller 13. The first protrusion 51 is located at the intersection point Q1 (refer to) where the small end face 133 intersects the rotation center line Cr of the tapered roller 13. Figure 7 The second protrusion 52 can contact at the intersection point Q2 (refer to) where the large end face 132 intersects with the rotation center line Cr of the tapered roller 13. Figure 7 (Contact at) location.

[0099] The small end face 133 of the tapered roller 13 contacts the first protrusion 51 of the small-diameter annular portion 41, thereby reducing the contact area. The large end face 132 of the tapered roller 13 contacts the second protrusion 52 of the large-diameter annular portion 42, thereby reducing the contact area. As a result, the sliding friction resistance between the tapered roller 13 and the small-diameter annular portion 41 and the large-diameter annular portion 42 is reduced.

[0100] Large diameter annular portion 42 (refer to) Figure 4 The bearing has an annular large-diameter main body portion 421 and a plurality of plate portions 422 extending radially inward from the large-diameter main body portion 421. The plate portions 422 face the large end face 132 of the tapered roller 13 and are provided intermittently in the circumferential direction of the bearing. In this embodiment, the plate portion 422 has a second protrusion 52 that contacts the large end face 132 of the tapered roller 13.

[0101] The plate portion 422 is able to retain grease between itself and the large end face 132 of the tapered roller 13. The plate portion 422 functions as a weir to block the grease. Through this grease, the sliding frictional resistance between the second protrusion 52 and the tapered roller 13 is reduced.

[0102] Furthermore, as described above, since the plate portion 422 is intermittently provided in the bearing circumferential direction, unwanted grease that has entered the pocket 15 can easily flow out between the multiple plate portions 422.

[0103] That is, the sliding friction resistance between the tapered roller 13 and the large-diameter annular portion 42 is reduced by the second protrusion 52 of the plate portion 422. At the same time, the arrangement of the plate portion 422 can suppress the increase of grease stirring resistance caused by the tapered roller 13.

[0104] Small diameter annular portion 41 (refer to) Figure 5 , Figure 7 The bearing has a small-diameter main body portion 411 connected to the column 43 and an extension portion 412 extending radially inward from the small-diameter main body portion 411. The extension portion 412 faces the small end face 133 of the tapered roller 13. In this embodiment, the extension portion 412 has a first protrusion 51 that contacts the small end face 133 of the tapered roller 13.

[0105] According to this structure, external grease is less likely to enter the pocket 15 of the retainer 14 due to the extension 412, which can suppress the increase in grease stirring resistance caused by the tapered roller 13. Furthermore, the first protrusion 51 provided by the extension 412 can reduce the sliding friction resistance between the tapered roller 13 and the small-diameter annular portion 41.

[0106] The bearing device 10 of this embodiment (refer to) Figure 1 The vehicle has a first bearing portion 71 on the inside of the vehicle, which includes a plurality of tapered rollers 13 and a cage 14 for holding the tapered rollers 13, and a second bearing portion 72 on the outside of the vehicle, which includes a plurality of tapered rollers 13 and a cage 14 for holding the tapered rollers 13.

[0107] The first bearing portion 71 has an inner ring 32, an outer ring 111 formed by a portion of the vehicle interior of the outer square member 11, a plurality of tapered rollers 13 disposed between the inner ring 32 and the outer ring 111, and an annular cage 14 for retaining the tapered rollers 13.

[0108] The second bearing section 72 has an inner ring 121 formed by a portion of the outer side of the inner square member 12, an outer ring 112 formed by a portion of the outer side of the outer square member 11, a plurality of tapered rollers 13 disposed between the inner ring 121 and the outer ring 112, and an annular cage 14 for holding the tapered rollers 13.

[0109] The retainers 14 of the first bearing section 71 and the second bearing section 72 are retainers as described in the above embodiment.

[0110] As described above, the structure of the bearing portion having tapered rollers 13 and a cage 14 can also be applied to rolling bearings other than the wheel rolling bearing assembly 10. That is, the various structures of the present invention can also be applied to general-purpose tapered roller bearings, which have an inner ring, an outer ring, a plurality of tapered rollers disposed between the inner ring and the outer ring, and an annular cage holding the plurality of tapered rollers.

[0111] [other]

[0112] exist Figure 1 In the case of the bearing assembly 10 shown, the inner square member 12 has a flange 34 for mounting the wheel 7, and serves as a rotating ring. The outer square member 11 is mounted on the vehicle body (the suspension assembly), and serves as a fixed ring. Regarding the present invention, although not shown, it is also possible for the inner square member 12 to be a fixed ring and the outer square member 11 to be a rotating ring.

[0113] That is, the present invention only requires that one of the inner square member 12 and the outer square member 11 has a flange 34 for mounting the wheel 7, and the other of the inner square member 12 and the outer square member 11 is mounted on the wheel rolling bearing device 10 of the vehicle body.

[0114] The above embodiments are illustrative in all respects and are not restrictive. The scope of the invention is defined by the claims rather than the above embodiments, and includes all modifications within the range equivalent to the structures described in the claims.

[0115] Explanation of reference numerals in the attached figures

[0116] 7 wheels

[0117] 10 Rolling bearing assembly for wheels

[0118] 11 External components

[0119] 12 Inner square components

[0120] 13 Tapered rollers

[0121] 14. Cage

[0122] 15 pockets

[0123] 41. Small diameter annular portion

[0124] 42 Large-diameter annular portion

[0125] 43 columns

[0126] 44 Side View

[0127] 45 Contact surface

[0128] 46 Non-contact surfaces

[0129] 48 First radial outer surface (radial outer surface)

[0130] 51 First convex part

[0131] 52 Second convex part

[0132] 111 Outer ring

[0133] 112 Outer ring

[0134] 121 Inner Circle

[0135] 131 Outer Peripheral Surface

[0136] 132 Large end face

[0137] 133 Small end face

[0138] 411 Main part of the trail

[0139] 412 Extension

[0140] 421 Large diameter main body

[0141] 422 Plate Section

[0142] 422a end

[0143] 431 First column

[0144] 432 Second column

[0145] B1 Width Dimension

[0146] Q1 Intersection

[0147] Q2 intersection

Claims

1. A rolling bearing assembly for a wheel, comprising an inner square member, an outer square member, a plurality of tapered rollers disposed between the inner square member and the outer square member, and an annular cage for holding the plurality of tapered rollers. One of the inner square member and the outer square member has a flange for wheel mounting, and the other of the inner square member and the outer square member is mounted on the vehicle body. The cage has a small-diameter annular portion, a large-diameter annular portion with a diameter larger than the small-diameter annular portion, and a plurality of posts connecting the small-diameter annular portion and the large-diameter annular portion. The column has a contact surface on the side of the column located on the side of the small-diameter annular portion and a non-contact surface located on the side of the large-diameter annular portion. The contact surface can contact the outer peripheral surface of the tapered roller. The non-contact surface is located further away from the tapered roller in the bearing circumferential direction than the contact surface, and does not contact the outer circumferential surface of the tapered roller.

2. The rolling bearing device for wheels according to claim 1, wherein, The large-diameter annular portion has: The annular, large-diameter main body is continuous in the circumferential direction of the bearing; and Multiple plates extend radially inward from the large-diameter main body and are opposite to the large end face of the tapered roller, and are intermittently arranged in the circumferential direction of the bearing.

3. The rolling bearing device for wheels according to claim 2, wherein, The small-diameter annular portion has a first protrusion that contacts the small end face of the tapered roller. The plate portion has a second protrusion that contacts the large end face of the tapered roller. The first protrusion can contact at the intersection of the small end face and the rotation center line of the tapered roller. The second protrusion can contact at the intersection of the large end face and the rotation center line of the tapered roller.

4. The rolling bearing device for wheels according to claim 1, wherein, The small-diameter annular portion has a first protrusion that contacts the small end face of the tapered roller. The large-diameter annular portion has a second protrusion that contacts the large end face of the tapered roller. The first protrusion can contact at the intersection of the small end face and the rotation center line of the tapered roller. The second protrusion can contact at the intersection of the large end face and the rotation center line of the tapered roller.

5. The rolling bearing device for wheels according to claim 1 or 2, wherein, The small-diameter annular portion has: The small-diameter main body is connected to the column; and The extension portion extends radially inward from the small-diameter main body portion and is positioned opposite the small end face of the tapered roller. The extension extends to a position further inward of the bearing radial direction than the rotation center line of the tapered roller.

6. The rolling bearing device for wheels according to claim 5, wherein, The extension has a first protrusion that contacts the small end face of the tapered roller. The large-diameter annular portion has a second protrusion that contacts the large end face of the tapered roller. The first protrusion can contact at the intersection of the small end face and the rotation center line of the tapered roller. The second protrusion can contact at the intersection of the large end face and the rotation center line of the tapered roller.

7. The rolling bearing device for wheels according to claim 1 or 2, wherein, The column has: a first column portion having the contact surface and extending from the small-diameter annular portion; and a second column portion having the non-contact surface and connecting the first column portion and the large-diameter annular portion. The width of the radially outer side of the first column is constant along the length of the column, or gradually increases toward the second column.

8. The rolling bearing device for wheels according to claim 1 or 2, wherein, The column has: a first column portion having the contact surface and extending from the small-diameter annular portion; and a second column portion having the non-contact surface and connecting the first column portion and the large-diameter annular portion. The radial dimension of the bearing in the second column is smaller than that in the first column.

9. A tapered roller bearing comprising an inner ring, an outer ring, a plurality of tapered rollers disposed between the inner ring and the outer ring, and an annular cage for retaining the tapered rollers, wherein, The cage has a small-diameter annular portion, a large-diameter annular portion with a diameter larger than the small-diameter annular portion, and a plurality of posts connecting the small-diameter annular portion and the large-diameter annular portion. The column has a contact surface on the side of the column located on the side of the small-diameter annular portion and a non-contact surface located on the side of the large-diameter annular portion. The contact surface can contact the outer peripheral surface of the tapered roller. The non-contact surface is located further away from the tapered roller in the bearing circumferential direction than the contact surface, and does not contact the outer circumferential surface of the tapered roller.

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