Rolling bearing device

Abstract

To provide a rolling bearing device capable of preventing a connection ring from falling from a locking recessed groove provided in an inner ring outside in the axial direction, during assembly work to a support shaft.SOLUTION: A connection ring 21 includes: a plurality of opening windows 36; and a plurality of locking protrusion parts 37a, 37b formed on both side parts in the axial direction of an opening edge part of the plurality of opening windows 36 and locked in locking recessed grooves 26a, 26b of inner rings 19a, 19b. The locking protrusion parts 37a, 37b have a bulging shape, and have pressing surfaces 38a, 38b including a shear surface 40. An end part radially outside of the shear surface 40 is positioned radially outside with respect an end part radially outside of chamfer parts 28a, 28b provided at surfaces 27a, 27b to be pressed of the locking recessed grooves 26a, 26b, and the shear surface 40 is brought into contact with a radially outside portion with respect to the chamfer parts 28a, 28b out of the surfaces 27a, 27b to be pressed.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] A rolling bearing device called a hub unit bearing is used to rotatably support the wheels of an automobile. Figures 16 and 17 show the structure described in JP 2011-27130 A (Patent Document 1) as an example of a rolling bearing device used to rotatably support and rotate the wheels (drive wheels) of heavy vehicles such as trucks and buses.

[0003] The rolling bearing device 100 rotatably supports a hub wheel 102 around an axle tube 101. A drive shaft 103 is inserted into the inside of the axle tube 101. A flange 104 is provided at the end of the drive shaft 103, and the hub wheel 102 is fixed to the flange 104. A drive wheel 105 and a braking rotor 106 are each fixed to the hub wheel 102. With this configuration, the drive wheel 105 and the braking rotor 106 are rotatably supported relative to the axle tube 101, and torque from the drive shaft 103 can be transmitted to the drive wheel 105 and the braking rotor 106.

[0004] As shown in FIG. 17, the rolling bearing device 100 is a double-row tapered roller bearing and includes an outer ring 107 that rotates when in use, a pair of inner rings 108a, 108b that do not rotate when in use, a plurality of rolling elements 109a, 109b, and a connecting ring 110.

[0005] It should be noted that with regard to the rolling bearing device 100, the axially outer side refers to the left side in Figures 16 and 17, which is the outer side in the width direction of the vehicle when assembled to the vehicle, and the axially inner side refers to the right side in Figures 16 and 17, which is the central side in the width direction of the vehicle when assembled to the vehicle.

[0006] The outer ring 107 has double-row outer ring raceways 111a, 111b on its inner circumferential surface. The outer ring 107 is fitted into the hub ring 102 by interference fit.

[0007] The inner rings 108a, 108b have single-row inner ring raceways 112a, 112b in the axially intermediate portion of the outer circumferential surface, and large flange portions 113a, 113b and small flange portions 114a, 114b at both axial ends of the outer circumferential surface. The pair of inner rings 108a, 108b are externally fitted onto the axle tube 101 with a clearance fit, with their opposing small diameter end faces butting against each other.

[0008] The rolling elements 109a, 109b are tapered rollers, and are arranged between the outer ring raceways 111a, 111b and the inner ring raceways 112a, 112b, with a plurality of rolling elements in each row, so as to be able to roll freely.

[0009] The connecting ring 110 is configured as a segmented annular shape having one discontinuous portion in the circumferential direction, and has a U-shaped cross section. The connecting ring 110 has a pair of flange portions 115a, 115b having a circular ring shape, and a cylindrical portion 116 that connects the radially inner ends of the pair of flange portions 115a, 115b.

[0010] The connecting ring 110 connects the pair of inner rings 108a, 108b by engaging the pair of flanges 115a, 115b with engaging grooves 117a, 117b provided on the inner circumferential surfaces of the inner rings 108a, 108b.

[0011] In addition, JP 2011-27130 A discloses a structure in which a driving wheel 105 is supported rotatably relative to an axle tube 101 by a rolling bearing device 100. However, as disclosed in, for example, JP 2006-105304 A, a structure of a driven wheel support device in which a driven wheel is supported rotatably relative to a knuckle spindle by a rolling bearing device is also known in the art. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] JP 2011-27130 A [Patent Document 2] JP 2006-105304 A Summary of the Invention [Problem to be solved by the invention]

[0013] When assembling a rolling bearing device to a support shaft such as an axle tube or a knuckle spindle, it is necessary to assemble the rolling bearing device and the hub wheel, which are heavy, onto the support shaft.

[0014] As shown in Fig. 18, when an assembly 118 of a hub wheel 102a for a driven wheel and a rolling bearing device 100 is mounted on a knuckle spindle 119, a state occurs in which the axially inner inner ring 108b is fitted onto the fitting surface 120 of the knuckle spindle 119, but the axially outer inner ring 108a is not. In this state, the axially outer inner ring 108a is eccentric vertically downward (toward the road surface, the lower side of Fig. 18) with respect to the axially inner inner ring 108b as shown by arrow α, so that a vertically upper portion of the locking groove 117a provided on the inner peripheral surface of the axially outer inner ring 108a is likely to interfere with a step portion 121 present on the outer peripheral surface of the knuckle spindle 119. As a result, an axial load inclined with respect to the central axis of the inner ring 108a is applied from the knuckle spindle 119 to the inner ring 108a, which may cause a problem such as the flange 115a of the connecting ring 110 falling off the locking groove 117a.

[0015] In particular, in the structure of the driven wheel support device as shown in Figure 18, the center of gravity of assembly 118 tends to be biased axially outward, causing assembly 118 to tilt in the direction indicated by arrow β, making the above-mentioned problem more likely to occur.

[0016] Japanese Patent Application Publication No. 2011-27130 discloses a technology for automatically correcting eccentricity that occurs in the inner ring on the axially outer side by forming a chamfered portion on the radially inner end of the surface of a locking groove provided in the inner ring on the axially outer side that faces the small flange portion in the axial direction, and by forming a chamfered portion on a step portion of an axle tube.

[0017] However, in the conventional structure described in JP 2011-27130 A, a pressed product having a U-shaped cross section is used as connecting ring 110, and flanges 115a, 115b are supported in a so-called cantilevered manner with respect to cylindrical portion 116, which tends to result in insufficient rigidity of flanges 115a, 115b and a large perpendicularity of flanges 115a, 115b with respect to the central axis of connecting ring 110. Therefore, even if eccentricity occurring in axially outer inner ring 108a is automatically corrected, it is difficult to sufficiently prevent flange 115a of connecting ring 110 from falling off locking groove 117a provided in axially outer inner ring 108a.

[0018] The present invention has been made to solve the above-mentioned problems, and has an object to provide a rolling bearing device that can prevent a connecting ring from falling off from a locking groove provided in an inner ring on the axially outer side during assembly to a support shaft such as an axle tube or knuckle spindle. [Means for solving the problem]

[0019] A rolling bearing device according to one aspect of the present invention includes an outer ring, a pair of inner rings, a plurality of rolling elements, and a connecting ring. The outer ring has a double row outer ring raceway on its inner circumferential surface. The pair of inner rings each have a single-row inner ring raceway in the axial middle portion of the outer circumferential surface, a large rib portion and a small rib portion at both axial ends of the outer circumferential surface, and each have an engagement groove on the inner circumferential surface. Each of the plurality of rolling elements is disposed between the outer ring raceway and the inner ring raceway. The connecting ring has a plurality of open windows arranged at a distance in the circumferential direction and a plurality of locking protrusions formed on both axial sides of the opening edge of each of the plurality of open windows, and connects the pair of inner rings by locking the plurality of locking protrusions into the locking grooves of the pair of inner rings. Each of the plurality of locking grooves has a retained surface that faces the large flange portion in the axial direction and has a chamfered portion formed on a radially inner end portion. Each of the plurality of locking protrusions has a bulging shape that protrudes radially outward, and has a holding surface including a shear surface in a portion facing the held surface. The radially outer end of the shearing surface is positioned radially outward of the radially outer end of the chamfered portion, and the shearing surface of the holding surface is abutted against a portion of the held surface that is radially outward of the chamfered portion.

[0020] In a rolling bearing device according to one aspect of the present invention, each of the multiple locking protrusions can be configured in a partial spherical shell shape, and the retaining surface can be a curved surface that is convex radially outward when viewed in the axial direction.

[0021] In the rolling bearing device according to one aspect of the present invention, a bent portion can be provided in the connecting ring between adjacent open windows in the circumferential direction. Effect of the Invention

[0022] According to one aspect of the rolling bearing device of the present invention, the connecting ring can be prevented from falling off from the locking groove provided in the inner ring on the axially outer side during assembly to a support shaft such as an axle tube or knuckle spindle. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a cross-sectional view showing a drive wheel support device incorporating a rolling bearing device according to a first embodiment. [Diagram 2] FIG. 2 is a half sectional view showing a rolling bearing device according to a first example of an embodiment. [Diagram 3] FIG. 3 is a partially enlarged view of FIG. [Figure 4] FIG. 4 is a partially enlarged view of FIG. [Diagram 5] FIG. 5 is a cross-sectional view showing an inner ring taken out from a rolling bearing device according to a first example of an embodiment. [Figure 6] FIG. 6 is an enlarged view of the portion X in FIG. [Figure 7]Figure 7 is a diagram shown to explain a manufacturing method of a connecting ring to be incorporated into a rolling bearing device according to a first example of an embodiment, in which (A) is a plan view of a base plate, (B) is a schematic cross-sectional view showing a process of forming a bulge in the base plate, and (C) is a schematic cross-sectional view showing a process of forming a window opening in the widthwise middle of the bulge. [Figure 8] FIG. 8 is a side view of an intermediate material obtained from a blank plate in the width direction of the intermediate material according to the first embodiment. [Figure 9] FIG. 9 is a plan view of the intermediate material as seen from above in FIG. [Figure 10] FIG. 10 is a plan view of a connecting ring obtained from an intermediate material in a free state, as viewed from the outer circumferential surface side of the connecting ring, in the first example of the embodiment. [Figure 11] FIG. 11 is a cross-sectional view taken along line AA in FIG. [Figure 12] FIG. 12 is a cross-sectional view taken along line BB in FIG. [Figure 13] FIG. 13 is an enlarged view of a portion Y in FIG. [Figure 14] FIG. 14 is a diagram showing a second example of the embodiment, and corresponds to FIG. [Figure 15] FIG. 15 is a diagram showing a second example of the embodiment, and corresponds to FIG. [Figure 16] FIG. 16 is a cross-sectional view showing a drive wheel support device incorporating a rolling bearing device of a conventional structure. [Figure 17] FIG. 17 is a partial cross-sectional view showing a rolling bearing device of a conventional structure. [Figure 18] FIG. 18 is a half sectional view illustrating the process of assembling an assembly in which a rolling bearing unit of a conventional structure is combined with a hub wheel for a driven wheel, onto a support shaft. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] [First Example of Implementation] A first embodiment will be described with reference to Figures 1 to 13. In this embodiment, a rolling bearing device of the present invention is applied to a drive wheel support device for heavy large vehicles such as trucks and buses.

[0025] [Overall configuration of the drive wheel support device] 1, the drive wheel support device 1 comprises a rolling bearing device 2, an axle tube 3 which is a support shaft, a hub wheel 4, and a drive shaft 5. The drive wheel support device 1 rotatably supports a drive wheel 6 such as a rear wheel of a truck and a braking rotor 7, and transmits drive torque to the drive wheel 6 and the braking rotor 7, and has a fully floating configuration.

[0026] In relation to the drive wheel support device 1, the axial outer side refers to the left side in Figure 1, which is the outer side in the width direction of the vehicle when assembled to the vehicle, and the axial inner side refers to the right side in Figure 1, which is the central side in the width direction of the vehicle when assembled to the vehicle.

[0027] The rolling bearing device 2 rotatably supports the hub wheel 4 around the axially outer end of the axle tube 3. The rolling bearing device 2 is disposed between the outer peripheral surface of the axle tube 3 and the inner peripheral surface of the hub wheel 4.

[0028] The axle tube 3, also called an axle housing, has a cylindrical shape and its axially inner end is connected to a differential case (not shown). Therefore, the axle tube 3 does not rotate even during use. The internal space of the axle tube 3 is connected to the internal space of the differential case.

[0029] The outer peripheral surface of the axle tube 3 is provided with a male threaded portion 8, an outer step portion 9, an inner diameter side fitting surface portion 10, and an inner step portion 11 in this order from the axial outside. The male threaded portion 8 is provided at the axial outside end of the outer peripheral surface of the axle tube 3. A nut 12 is screwed onto the male threaded portion 8 to fix the rolling bearing device 2 to the axle tube 3 and to apply axial force to the pair of inner rings 19a, 19b to optimize the internal gap of the rolling bearing device 2. The inner diameter side fitting surface portion 10 is cylindrical and provided at the axial middle portion of the outer peripheral surface of the axle tube 3. The inner diameter side fitting surface portion 10 has an outer diameter larger than that of the male threaded portion 8. The outer step portion 9 is provided between the male threaded portion 8 and the inner diameter side fitting surface portion 10 in the axial direction, and connects the male threaded portion 8 and the inner diameter side fitting surface portion 10. The inner step portion 11 is a circular ring surface facing outward in the axial direction, and is provided in a portion adjacent to the inner side of the inner diameter side fitting surface portion 10 in the axial direction.

[0030] The drive shaft 5, also known as an axle shaft, is solid and inserted into the inside of the axle tube 3. The drive shaft 5 is arranged coaxially with the axle tube 3. The axially inner end of the drive shaft 5 is connected to a differential gear (not shown). Therefore, the drive shaft 5 rotates when in use. The drive shaft 5 is provided with an outward flange-shaped flange 13 at the axially outer end protruding from the axle tube 3. The hub wheel 4 is fixed to the flange 13 with a plurality of bolts 14.

[0031] The hub wheel 4 has an annular shape. The hub wheel 4 has a cylindrical outer diameter side fitting surface 15 on its inner circumferential surface, and a rotating flange 16 at the axially middle portion of its outer circumferential surface. The driving wheel 6 is fixed to the rotating flange 16 by a connecting member 17 such as a hub bolt or a stud. The braking rotor 7 is fixed to the axially inner side of the hub wheel 4 by a bolt 14.

[0032] With the above-described configuration, the drive wheel support device 1 rotatably supports the drive wheels 6 and the braking rotor 7 relative to the axle tube 3, and is capable of transmitting torque from the drive shaft 5 to the drive wheels 6 and the braking rotor 7. Furthermore, in the full floating type drive wheel support device 1, the vehicle load is not supported by the drive shaft 5, but by the axle tube 3. The drive shaft 5 is only responsible for transmitting torque.

[0033] The specific structure of the rolling bearing device 2 of this embodiment will be described below with reference to FIGS. With respect to the rolling bearing device 2, the axially outer side refers to the left side in Figures 2 to 6, which is the outer side in the width direction of the vehicle when assembled to the vehicle, and the axially inner side refers to the right side in Figures 2 to 6, which is the central side in the width direction of the vehicle when assembled to the vehicle.

[0034] <Rolling bearing device> The rolling bearing device 2 is a back-to-back type double row tapered roller bearing and is an outer ring rotating type. The rolling bearing device 2 includes an outer ring 18 that rotates when in use, a pair of inner rings 19a, 19b that do not rotate when in use, a plurality of rolling elements 20a, 20b, and a connecting ring 21.

[0035] Paddle Wheel The outer ring 18 is made of hard metal such as bearing steel and has an annular shape. The outer ring 18 has, on its inner peripheral surface, double-row outer ring raceways 22a, 22b in the form of conical concave surfaces whose inner diameters increase as they move away from each other in the axial direction. The outer peripheral surface of the outer ring 18 is configured as a substantially cylindrical surface. When the rolling bearing device 2 is mounted on the vehicle, the outer ring 18 is fitted and fixed to the outer diameter side fitting surface portion 15 provided on the inner peripheral surface of the hub wheel 4 by an interference fit. Therefore, the outer ring 18 rotates together with the hub wheel 4.

[0036] Inner Circle Each of the inner rings 19a, 19b is made of hard metal such as bearing steel and has an annular shape. The inner rings 19a, 19b have a single-row inner ring raceway 23a, 23b with a conical convex surface shape in the axial middle of the outer peripheral surface, and large flanges 24a, 24b and small flanges 25a, 25b at both axial ends of the outer peripheral surface. The large flanges 24a, 24b and small flanges 25a, 25b are disposed on both axial ends of the inner ring raceway 23a, 23b. The outer diameter of the inner rings 19a, 19b is larger at the large diameter end with the large flanges 24a, 24b than at the small diameter end with the small flanges 25a, 25b.

[0037] The inner rings 19a, 19b have locking grooves 26a, 26b in a portion of their inner circumferential surfaces that is located radially inward of the small flanges 25a, 25b. The locking grooves 26a, 26b are annular grooves that are formed around the entire inner circumferential surfaces of the inner rings 19a, 19b. The locking grooves 26a, 26b have a substantially rectangular cross-sectional shape and are open only to the inner circumferential surfaces of the inner rings 19a, 19b.

[0038] The locking grooves 26a, 26b have clamped surfaces 27a, 27b facing the large flange portions 24a, 24b in the axial direction. Therefore, the clamped surfaces 27a, 27b face opposite sides in the axial direction when the small diameter end faces of the inner rings 19a, 19b are butted against each other.

[0039] The clamped surfaces 27a, 27b have chamfered portions 28a, 28b having an arc-shaped generatrix shape at their radially inner ends, and have annular flat portions 29a, 29b adjacent to the radially outer side of the chamfered portions 28a, 28b and perpendicular to the central axis of the inner rings 19a, 19b.

[0040] As shown in FIG. 4, the radial dimension h 29 is the radial dimension h of the chamfered portions 28a and 28b 28 greater than (h 29 >h 28 ).

[0041] The inner rings 19a, 19b have cylindrical small diameter surface portions 30a, 30b at the axially intermediate portion of their inner circumferential surfaces. The inner rings 19a, 19b have cylindrical large diameter surface portions 31a, 31b, the inner diameter of which is larger than that of the small diameter surface portions 30a, 30b and smaller than that of the bottom surfaces of the locking grooves 26a, 26b, at the axially opposite portion of the inner circumferential surfaces of the inner rings 19a, 19b. The large diameter surface portions 31a, 31b are connected to the chamfered portions 28a, 28b of the clamped surfaces 27a, 27b.

[0042] The inner rings 19a, 19b have seal grooves 32a, 32b (see FIG. 2) in a portion of their inner circumferential surfaces that is located radially inward of the large flange portions 24a, 24b. The seal grooves 32a, 32b are annular grooves formed over the entire periphery of the inner circumferential surfaces of the inner rings 19a, 19b. Of the seal grooves 32a, 32b, the seal groove 32b provided in the inner ring 19b on the axially inner side is fitted with an annular seal ring 33. The seal ring 33 is sandwiched between the inner ring 19b and the inner step portion 11 of the axle tube 3 to seal that portion.

[0043] The pair of inner rings 19a, 19b are arranged coaxially with the outer ring 18 on the radially inner side of the outer ring 18 with their small diameter end faces abutting against each other. The pair of inner ring raceways 23a, 23b are arranged in double rows at positions radially facing the double row outer ring raceways 22a, 22b.

[0044] When the rolling bearing device 2 is installed on a vehicle, the inner rings 19a, 19b are fitted with a clearance fit onto the inner diameter side fitting surface 10 provided on the outer circumferential surface of the axle tube 3. The inner rings 19a, 19b are also sandwiched in the axial direction between an inner step 11 provided on the outer circumferential surface of the axle tube 3 and the nut 12. This fixes the rolling bearing device 2 to the axle tube 3, and applies axial force to the pair of inner rings 19a, 19b, optimizing the internal gap of the rolling bearing device 2. The amount of screwing (screwed position) of the nut 12 is set, for example, so that the internal gap in the axial direction of the rolling bearing device 2 is zero or a slight positive or negative value.

[0045] In this example, the pair of inner rings 19a, 19b are made of the same material and are arranged in opposite directions in the axial direction. Therefore, the inner rings 19a, 19b have the same shapes and dimensions of each part, except for the fact that they are oriented in opposite directions in the axial direction. However, when implementing the present invention, it is also possible to use materials whose parts have different shapes and dimensions as the pair of inner rings.

[0046] Rolling Body Each of the rolling elements 20a, 20b is a tapered roller, made of, for example, bearing steel or ceramic. The rolling elements 20a, 20b are arranged between the outer ring raceways 22a, 22b and the inner ring raceways 23a, 23b in a state of being held by the cages 34a, 34b so as to be freely rollable. The rolling elements 20a in the axially outer row have a part of their axially outer end faces in contact with the large rib portion 24a, and a part of their axially inner end faces closely facing the small rib portion 25a. The rolling elements 20b in the axially inner row have a part of their axially inner end faces in contact with the large rib portion 24b, and a part of their axially outer end faces closely facing the small rib portion 25b.

[0047] 《Connection ring》 The connecting ring 21 is for connecting the pair of inner rings 19a, 19b in the axial direction and is made of a metal plate. The connecting ring 21 is configured as a curved plate curved in an arc shape in a free state. The connecting ring 21 is attached to the pair of inner rings 19a, 19b in a state in which it is elastically deformed into a segmented ring shape or a ring shape having a C-shaped end face shape.

[0048] The axial dimension of the connecting ring 21 is slightly smaller than the axial dimension between the distal ends (small diameter surface portions 30a, 30b) of the pair of locking grooves 26a, 26b when the pair of inner rings 19a, 19b are butted together.

[0049] The connecting ring 21 has a plurality of opening windows 36 and a plurality of locking protrusions 37a, 37b.

[0050] The multiple open windows 36 are disposed at equal intervals in the circumferential direction of the connecting ring 21. The open windows 36 are through holes that penetrate the connecting ring 21 in the radial direction, and have a rounded rectangular shape (rounded square shape in the illustrated example) when viewed in the radial direction. The open windows 36 are formed in the axial middle part of the connecting ring 21.

[0051] The axial dimension of the open window 36 is smaller than the axial dimension of the connecting ring 21. Specifically, the axial dimension of the open window 36 is about 2 / 5 to 3 / 5 of the axial dimension of the connecting ring 21. In addition, the axial dimension of the open window 36 is the same as or slightly larger than the axial distance between the pair of held surfaces 27a, 27b (flat surfaces 29a, 29b) when the pair of inner rings 19a, 19b are butted against each other.

[0052] The locking protrusions 37a, 37b are formed on both axial sides of the opening edge of each of the opening windows 36. In this example, the locking protrusions 37a, 37b are formed in the circumferential center of both axial sides of the opening edge of each of the opening windows 36. Therefore, the phase of the locking protrusions 37a, 37b in the circumferential direction coincides with the phase of the opening window 36 in the circumferential direction. Of the locking protrusions 37a, 37b, one locking protrusion 37a is formed on the axial outer side of the opening edge of the opening window 36, and the other locking protrusion 37b is formed on the axial inner side of the opening edge of the opening window 36.

[0053] Each of the locking protrusions 37a, 37b has a bulging shape that protrudes radially outward. In this example, each of the locking protrusions 37a, 37b is configured in a partial spherical shell shape (quarter spherical shell shape).

[0054] The locking protrusion 37a on the axially outer side has the largest outer diameter (and inner diameter) at the apex provided at the circumferential center of the end portion on the axially inner side, and the outer diameter (and inner diameter) curvedly decreases from the apex toward both circumferential sides and toward the axially outer side. The locking protrusion 37b on the axially inner side has the largest outer diameter (and inner diameter) at the apex provided at the circumferential center of the end portion on the axially outer side, and the outer diameter (and inner diameter) curvedly decreases from the apex toward both circumferential sides and toward the axially inner side. Therefore, the cross-sectional shape of the connecting ring 21 at the circumferential center of the locking protrusions 37a and 37b is approximately V-shaped as shown in FIG. 3. In addition, the locking protrusions 37a and 37b in this example protrude radially outward at their respective apexes by approximately the plate thickness of the connecting ring 21.

[0055] When the connecting ring 21 is attached to a pair of inner rings 19a, 19b, the multiple locking protrusions 37a, 37b enter from the radially inner side into the locking grooves 26a, 26b provided on the inner surfaces of the inner rings 19a, 19b and are locked into the locking grooves 26a, 26b.

[0056] The locking protrusions 37a, 37b have holding surfaces 38a, 38b at portions facing the held surfaces 27a, 27b of the locking grooves 26a, 26b in the axial direction.

[0057] 4, the clamping surfaces 38a, 38b have, in order from the radially inner side, a sagging surface 39, a shear surface 40, a fracture surface 41, and a burr 42. In this example, the clamping surfaces 38a, 38b are curved in an arc shape so that the radially outer side is convex when viewed in the axial direction (see FIG. 11).

[0058] The sagging surface 39 has a convex arc-shaped cross section and is provided at the radially inner end of the holding surfaces 38a, 38b. The sagging surface 39 is curved and inclined in a direction approaching the center of the opening window 36 in the axial direction as it goes radially outward.

[0059] The shearing surface 40 is provided at the radially middle portion of the clamping surfaces 38a, 38b, and is disposed adjacent to the radially outer side of the sagging surface 39. The shearing surface 40 is a smooth surface perpendicular to the central axis of the connecting ring 21. The shearing surface 40 is located closest to the axial center of the connecting ring 21 among the clamping surfaces 38a, 38b. In other words, the shearing surface 40 is located closest to the clamped surfaces 27a, 27b among the clamping surfaces 38a, 38b.

[0060] The fracture surface 41 is provided on the radially outer portion of the holding surfaces 38a, 38b, and is disposed adjacent to the radially outer side of the shear surface 40. The fracture surface 41 is a surface that is inclined in a direction away from the center of the opening window 36 in the axial direction as it goes radially outward.

[0061] The burrs 42 are provided on the radially outer ends of the clamping surfaces 38a, 38b, and are disposed adjacent to the radially outer side of the fractured surface 41. Note that the burrs can be removed from the clamping surfaces by polishing or abrasive processing.

[0062] In this example, the radial dimension H of the holding surfaces 38a and 38b from the radially inner end of the sagging surface 39 to the radially outer end of the shearing surface 40 is 38 The radial dimension h of the chamfered portions 28a, 28b provided on the clamped surfaces 27a, 27b 28 (H 38 >h 28 ).

[0063] The connecting ring 21 further has a plurality of notches 43 (see FIG. 2). The notches 43 are for phase alignment (indexing) during press working and are provided at both axial end portions of the connecting ring 21, but may be provided on only one axial side. In this example, the notches 43 are provided at portions of the connecting ring 21 whose phase in the circumferential direction coincides with the phases of the opening window 36 and the locking protrusions 37a, 37b, but they do not necessarily have to be provided in the same phase as the opening window 36 and the locking protrusions 37a, 37b as long as they are at the same pitch.

[0064] The connecting ring 21 axially connects the pair of inner rings 19a, 19b by engaging a plurality of locking protrusions 37a, 37b with locking recessed grooves 26a, 26b provided on the inner circumferential surfaces of the inner rings 19a, 19b.

[0065] In this example, with the multiple locking protrusions 37a, 37b locked in the locking grooves 26a, 26b, at the circumferential middle portion of the locking protrusions 37a, 37b, the radially outer end of the shear surface 40 provided on the clamping surfaces 38a, 38b is positioned radially outward from the radially outer end of the chamfered portions 28a, 28b provided at a circumferential position axially opposite to the shear surface 40.

[0066] Furthermore, with the multiple locking protrusions 37a, 37b locked in the locking grooves 26a, 26b, the outer peripheral surface of the portion of the connecting ring 21 that is circumferentially out of the opening window 36 is in elastic contact with the large diameter surface portions 31a, 31b of the inner rings 19a, 19b. Therefore, at the circumferential center of the locking protrusions 37a, 37b, the radially inner end of the sagging surface 39 and the radially inner end of the chamfered portions 28a, 28b are in the same radial position.

[0067] Furthermore, with the multiple locking protrusions 37a, 37b locked in the locking grooves 26a, 26b, the inner peripheral surface of the connecting ring 21 is located on an imaginary cylindrical surface that is coaxial with and has the same diameter as the small diameter surface portions 30a, 30b of the inner rings 19a, 19b, or is located radially outward of the imaginary cylindrical surface.

[0068] In this example, in the circumferential middle portion of the locking protrusions 37a, 37b, the radially outer end of the sheared surface 40 is positioned radially outward from the radially outer ends of the chamfered portions 28a, 28b, so that the sheared surface 40 abuts against the flat portions 29a, 29b which are positioned radially outward from the chamfered portions 28a, 28b.

[0069] <Sealing material> The rolling bearing device 2 in this example further includes a sealing member 45 that seals the butt joint 44 between the pair of inner rings 19a, 19b to prevent the grease sealed in the internal space of the rolling bearing device 2 from leaking into the space within the axle tube 3 and to prevent the differential oil present in the axle tube 3 from entering the internal space of the rolling bearing device 2.

[0070] The seal member 45 is made of an elastic material such as acrylonitrile butadiene rubber (NBR, high hardness nitrile) and is configured in an annular shape as a whole. The seal member 45 has a substantially T-shaped cross section. The radially inner part of the seal member 45 is axially sandwiched between the small diameter side end faces of the pair of inner rings 19a, 19b. The radially outer part of the seal member 45 is engaged with the small flange parts 25a, 25b so as to straddle the butt part 44 in the axial direction. In addition, when carrying out the present invention, the seal member can be configured from a seal part made of an elastic material and a metal core. The seal member can also be disposed radially inside the butt part.

[0071] 《Sealing device》 The rolling bearing device 2 of this example further includes a pair of sealing devices 46a, 46b for sealing both axial openings of the internal space existing between the inner peripheral surface of the outer ring 18 and the outer peripheral surfaces of the pair of inner rings 19a, 19b. One of the sealing devices 46a is a garter spring type seal ring, and is disposed between the axially outer side of the inner peripheral surface of the outer ring 18 and the outer peripheral surface of the large flange portion 24a constituting the inner ring 19a. It prevents the grease sealed in the internal space of the rolling bearing device 2 from leaking into the space inside the axle tube 3, and prevents the differential oil present inside the axle tube 3 from entering the internal space of the rolling bearing device 2. The other sealing device 46b is a combination seal ring that is arranged between the axially inner portion of the inner surface of the outer ring 18 and the outer surface of the large flange portion 24b that constitutes the inner ring 19b, and prevents the grease sealed in the internal space of the rolling bearing device 2 from leaking into the external space, and also prevents foreign matter such as muddy water present in the external space from entering the internal space of the rolling bearing device 2.

[0072] Next, a method for manufacturing the connecting ring 21 of this embodiment will be described with reference to FIGS. First, a metal plate such as a steel plate is punched out by press working to obtain a strip-shaped raw plate (blank) 47 having a plurality of index notches 43 formed at equal intervals on both ends in the width direction, as shown in FIG. 7(A).

[0073] Next, as shown in FIG. 7B, the blank 47 is pressed using a first punch 48 and a first die 49. The first punch 48 has a pressing portion 50 having a substantially oval planar shape and an arc-shaped cross-sectional shape. The outer surface shape of the pressing portion 50 at both ends in the width direction matches the inner surface shape of the locking protrusions 37a, 37b. The first die 49 has a concave receiving surface 51. The inner surface shape of the receiving surface 51 at both ends in the width direction matches the outer surface shape of the locking protrusions 37a, 37b.

[0074] In this process, the blank 47 is positioned relative to the first punch 48 and the first die 49 using the index notch 43 provided in the blank 47, and one by one, a dome-shaped (hollow) bulge 52 having an oval shape in plan view is formed in the blank 47 at a location that coincides with the phase of the notch 43, thereby obtaining an intermediate material 53 as shown in Figures 8 and 9.

[0075] When forming the bulging portions 52, part of the material of the blank 47 moves in the pushing direction of the first punch 48 (toward the lower side in (B) of FIG. 7). Therefore, as shown in FIG. 8, the intermediate material 53 having the bulging portions 52 formed at multiple points in the circumferential direction is curved in an arc shape so that the surface on the side where the bulging portions 52 are formed is convex.

[0076] Next, as shown in FIG. 7C, the intermediate material 53 is subjected to a punching process (shearing process) by pressing using a second punch 54 and a second die 55. The second punch 54 has a processing part 56 having a substantially rectangular prism shape. The processing part 56 has a contour shape that matches the opening shape of the opening window 36. The second die 55 has a punching hole 57 in the center, and has concave receiving surfaces 58 on both sides of the punching hole 57 on the upper surface. The punching hole 57 is a tapered hole through which the processing part 56 can be inserted. The receiving surfaces 58 have an inner shape that matches the outer surface shapes of the ends (locking protrusions 37a, 37b) on both longitudinal sides of the bulging part 52.

[0077] In this process, the intermediate material 53 is positioned relative to the second punch 54 and the second die 55 using the index notch 43 provided in the intermediate material 53, while sequentially punching out portions of the intermediate material 53 that are in phase with the notch 43. As a result, an opening window 36 is formed in the longitudinal middle portion of the bulging portion 52, and locking protrusions 37a, 37b are formed from both longitudinal side portions (remaining portions) of the bulging portion 52, thereby obtaining a connecting ring 21 that has a curved plate shape in a free state as shown in Figures 10 to 13.

[0078] In this process, the blade of the processing part 56 is brought into contact with the concave inner surface of the bulging part 52, so that the blade of the processing part 56 does not contact the bulging part 52 uniformly but partially. As a result, the bulging part 52 is cut (sheared) in sequence from the part where the blade of the processing part 56 contacts, as if cutting with scissors, and a shearing effect is obtained. As a result, the ratio of the sheared surface to the cut surface constituting the opening edge part of the opening window 36 can be increased. Therefore, the ratio of the sheared surface 40 to the clamping surfaces 38a, 38b of the locking protrusions 37a, 37b can be increased. Since the connecting ring 21 is configured as a curved plate curved in an arc shape in a free state, when it is attached to the pair of inner rings 19a, 19b, it is elastically deformed into a partial annular shape or annular shape using a tool or the like.

[0079] According to the rolling bearing device 2 of this embodiment as described above, when the device is assembled to the axle tube 3, the connecting ring 21 can be effectively prevented from falling off the locking groove 26a provided in the inner ring 19a on the axially outer side.

[0080] That is, in this example, in the circumferential intermediate portion of the locking protrusions 37a, 37b, the radially outer end of the shearing surface 40 provided on the holding surfaces 38a, 38b is positioned radially outward from the radially outer end of the chamfered portions 28a, 28b provided on the held surfaces 27a, 27b, so that the shearing surface 40 abuts against the flat portions 29a, 29b positioned radially outward from the chamfered portions 28a, 28. That is, in this example, the shearing surface 40 of the holding surfaces 38a, 38b that has a small perpendicularity to the central axis of the connecting ring 21 abuts against the flat portions 29a, 29b of the held surfaces 27a, 27b.

[0081] In this example, the clamping surfaces 38a, 38b having the shear surface 40 are provided on the locking protrusions 37a, 37b, which have a bulging shape and thus have high rigidity. Also, the clamping surfaces 38a, 38b are provided on a part of the opening window 36, which is closed all around, thereby increasing the rigidity of the clamping surfaces 38a, 38b against deformation.

[0082] Therefore, in this example, even if the axially outer inner ring 19a is eccentric vertically downward relative to the axially inner inner ring 19b when assembling the assembly of the hub wheel 4 and the rolling bearing device 2 to the axle tube 3 and the locking groove 26a provided on the inner peripheral surface of the axially outer inner ring 19a interferes with the outer step portion 9 provided on the outer peripheral surface of the axle tube 3, it is possible to effectively prevent the locking protrusion 37a of the connecting ring 21 from falling off from the locking groove 26a. As a result, the rolling bearing device 2 of this example can prevent the pair of inner rings 19a, 19b from separating, and can also prevent the axially outer inner ring 19a from slipping out axially outward from the axle tube 3, improving the efficiency of the task of assembling the assembly of the hub wheel 4 and the rolling bearing device 2 to the axle tube 3.

[0083] Furthermore, in this example, when forming the bulge 52 on the blank 47 that is the material for the connecting ring 21, the blank 47 can be curved into an arc shape. Therefore, the connecting ring 21 can be easily elastically deformed into a segmented ring shape or a ring shape without a separate process of curving the blank 47. This reduces the manufacturing cost of the rolling bearing device 2 and improves the workability of installing the connecting ring 21.

[0084] [Second Example of the Implementation Form] The second embodiment will be described with reference to FIGS.

[0085] In this example, only the structure of the connecting ring 21a is different from the structure of the first example of the embodiment.

[0086] The connecting ring 21a of this example has a bent portion 59 between the open windows 36 adjacent to each other in the circumferential direction. The bent portion 59 is configured so that the outer peripheral surface side of the connecting ring 21a is convex and the inner peripheral surface side of the connecting ring 21a is concave. The curvature of the bent portion 59 is larger than the curvature of the portion deviating from the bent portion 59 in the circumferential direction. Since the connecting ring 21a has a plurality of bent portions 59, the curvature in the free state is larger than that of the connecting ring 21 of the first example of the embodiment.

[0087] In this example, in order to form the connecting ring 21a having the bent portion 59 as described above, the connecting ring 21 is processed into the shape of the connecting ring 21 of the first example of the embodiment through the process shown in Fig. 7, and then a bender bending process is performed between the opening windows 36 adjacent in the circumferential direction to increase the curvature of the connecting ring 21a. Note that the bent portions 59 are also formed one by one between the opening windows 36 adjacent in the circumferential direction by utilizing the notches 43.

[0088] In the present embodiment as described above, the curvature of the connecting ring 21a in a free state can be increased, and therefore the workability of mounting the connecting ring 21a to the pair of inner rings 19a, 19b can be improved.

[0089] In addition, in this example, since the bent portion 59 is formed by bending, the bent portion 59 can be formed without interference between the open window 36 and the locking protrusions 37a, 37b and the press machine. The curvature of the connecting ring can also be increased by roll bending, but when performing roll bending, interference between the bulge 52 (see FIG. 9) or the locking protrusions 37a, 37b (see FIG. 10) and the press machine becomes a problem, so roll bending must be performed before forming the bulge 52. However, in this case, work hardening occurs in the blank, which causes problems such as a reduction in the shear surface and an increase in the fracture surface with respect to the clamping surface of the locking protrusions formed by the cut surfaces. In this example, since the bent portion 59 is formed by bending, the proportion of the shear surface 40 can be sufficiently increased by the shearing effect with respect to the clamping surfaces 38a, 38b (see FIG. 13) of the locking protrusions 37a, 37b formed by the cut surfaces. The other configurations and effects are the same as those of the first embodiment.

[0090] Although the embodiment of the present invention has been described above, the present invention is not limited to this, and can be modified as appropriate without departing from the technical concept of the invention.

[0091] When carrying out the present invention, the seal member for sealing the butted portion and the pair of sealing devices for sealing the internal space of the rolling bearing device are not limited to those described in the embodiment, and can be modified as appropriate. Furthermore, the rolling bearing device of the present invention can be incorporated into the rotation support portion of various mechanical devices, including not only driving wheel support devices but also driven wheel support devices, for use. [Explanation of symbols]

[0092] 1 Drive wheel support device 2. Rolling bearing device 3 axle tube 4 Hub Wheel 5 Drive shaft 6 Drive wheels 7 Braking rotor 8 Male thread 9 Outer step 10 Inner diameter side fitting surface 11 Inner step 12 Nut 13 Flange 14 Volts 15 Outer diameter side fitting surface 16 Rotating flange 17 Connecting members 18 Outer ring 19a, 19b Inner ring 20a, 20b Rolling elements 21, 21a connected ring 22a, 22b Outer raceway 23a, 23b Inner raceway 24a, 24b Otsubabe 25a, 25b Small flange 26a, 26b Locking groove 27a, 27b Surface to be held down 28a, 28b Chamfered part 29a, 29b flat part 30a, 30b Small diameter surface part 31a, 31b Large diameter surface part 32a, 32b Seal groove 33 Seal ring 34a, 34b retainer 35, 35a Discontinuity 36 Opening window 37a, 37b Locking protrusion 38a, 38b Retaining surface 39 Droopy Face 40 Shear plane 41 Fracture surface 42 Bali 43 Cutout 44 Butt joint 45 Sealing material 46a, 46b Sealing device 47 Plain board 48 First Punch 49 First Die 50 Pressing part 51 Receiving surface 52 Bulge 53 Intermediate materials 54 Second Punch 55 2nd Die 56 Processing Department 57 Punched Hole 58 Receiving surface 59 Bend 100 Rolling bearing device 101 Axle tube 102, 102a Hub wheel 103 Drive shaft 104 Flange 105 Drive Wheel 106 Braking rotor 107 Outer Ring 108a, 108b Inner circle 109a, 109b rolling elements 110 Connected ring 111a, 111b outer raceway 112a, 112b Inner raceway 113a, 113b Otsubabe 114a, 114b Small flange 115a, 115b Tsuba 116 Cylindrical part 117a, 117b Locking groove 118 Assembly 119 Knuckle Spindle 120 Mating surface part 121 Step

Claims

1. an outer ring having a double row outer ring raceway on an inner circumferential surface; a pair of inner rings each having a single row inner ring raceway in an axially intermediate portion of an outer peripheral surface, a large flange portion and a small flange portion at both axial ends of the outer peripheral surface, and each having an engagement groove on an inner peripheral surface; A plurality of rolling elements disposed between the outer ring raceway and the inner ring raceway; a connecting ring having a plurality of open windows arranged spaced apart in a circumferential direction and a plurality of locking protrusions formed on both axial sides of an opening edge of each of the plurality of open windows, the plurality of locking protrusions being locked in the locking grooves of the pair of inner rings to connect the pair of inner rings, Each of the plurality of locking grooves has a retaining surface that faces the large flange portion in the axial direction and has a chamfered portion formed on a radially inner end portion, Each of the plurality of locking protrusions has a bulging shape protruding radially outward and has a holding surface including a shear surface at a portion facing the held surface, A radially outer end of the shearing surface is located radially outward from a radially outer end of the chamfered portion, and the shearing surface of the holding surface abuts against a radially outer portion of the held surface than the chamfered portion. Rolling bearing device.

2. Each of the plurality of locking protrusions has a partial spherical shell shape, The holding surface is curved so that the radially outer side is convex when viewed in the axial direction.

2. A rolling bearing device according to claim 1.

3. 2. The rolling bearing device according to claim 1, wherein the connecting ring has a bent portion between adjacent ones of the open windows in the circumferential direction.

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