Buffer construction

Abstract

It effectively suppresses shocks caused by the gap between the bearing and the retainer. [Solution] The cushioning structure 12 includes a bearing 40, a holder 50 that holds the outer ring 44 of the bearing so as to be movable in the axial direction, the holder 50 having a bottom portion 54 facing the outer ring 44 in the axial direction, and an annular cushioning member 60 that is assembled sandwiched between the outer ring 44 and the bottom portion 54. The cushioning member 60 includes a first metal member 70 having a flat plate portion 72 that contacts the outer ring 44 and a cylindrical portion 74 extending from the flat plate portion 72 toward the bottom portion 54, and a second elastomer member 80 that is provided sandwiched between the flat plate portion 72 and the bottom portion 54 and has a hollow portion S1, and the second member 80 is deformable to expand and contract in accordance with the movement of the bearing 40 while maintaining the hollow portion S1 when the bearing 40 moves along the axial direction.

Description

[Technical Field]

[0001] The present invention relates to a cushioning structure. [Background Art]

[0002] As a structure around a drive shaft provided in an automobile or the like, a structure around a differential gear is known. The structure around the differential gear includes a bearing that holds a rotating body including the gear by an inner ring, and a holding body that holds an outer ring of the bearing in a bottomed hole. The holding body holds the bearing in an axially relatively movable state. In such a structure, a gap whose size changes as the bearing moves is formed between the bearing and the bottomed hole. When the bearing continues to move to reduce the gap, the outer ring comes into contact with the bottom of the bottomed hole. At this time, there is a problem that impact and impact noise are generated between the outer ring and the holding body. As a method of suppressing impact caused by contact between the bearing and the bottomed hole, a method is known in which an annular adjusting member such as a metal shim material or a cushioning material made of a single elastomer is assembled into the gap between the bearing and the bottomed hole. As a structure in which a shim material is disposed between the bearing and the bottomed hole, the bearing structure described in Patent Document 1 is known. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2022-170880 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] When using shims as adjustment members, selecting and installing shims with the optimal thickness for the bearing and hole combination can suppress the impact associated with contact with the bearing as it moves axially. However, the size of the gap between the bearing and the hole is affected by the component tolerances and assembly tolerances of the bearing and hole. If a shim with an unoptimal thickness for impact suppression is installed between the bearing and hole, it may worsen the impact associated with contact with the bearing as it moves axially. Therefore, when using shims as adjustment members, the process of disassembling the structure, re-selecting the shim, reassembling, and re-evaluating after assembly must be repeated until it is determined in post-assembly evaluation that the optimal shim has been installed for impact suppression. In this case, the productivity of the structure decreases. In the structure surrounding the differential gear of an automobile, when the gear motion is switched between powered and regenerative, the load torque associated with the gear motion switching is transmitted to the adjustment member via a bearing. Annular cushioning material made of elastomer alone has poor durability against load torque. Therefore, when a cushioning material made of elastomer alone is assembled as an adjustment member, repeated loads due to the load torque cause the cushioning material to deteriorate or break in a short period of time, resulting in a loss of cushioning performance.

[0005] This disclosure aims to provide a cushioning member capable of effectively suppressing impacts caused by the gap between a bearing and a retainer. [Means for solving the problem]

[0006] Aspects of this disclosure include a bearing having an outer ring, A holder that holds the outer ring so as to be movable in the axial direction, the holder having a portion facing the outer ring in the axial direction, The cushioning structure has an annular cushioning member around the axis, which is assembled in a state sandwiched between the outer ring and the opposing part. The cushioning member is A first metal component, The flat plate portion that contacts the outer ring, A cylindrical portion extending from the flat plate portion toward the opposing portion, A first member having, A second member made of elastomer, which is provided so as to be sandwiched between the flat plate portion and the opposing portion, and which has a hollow portion, is deformable to expand and contract in accordance with the movement of the bearing while maintaining the hollow portion when the bearing moves along the axial direction, It holds. [Effects of the Invention]

[0007] According to this disclosure, impacts caused by the gap between the bearing and the retainer can be effectively suppressed. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view of the buffer structure according to the embodiment. [Figure 2] This is a cross-sectional view of the cushioning member according to the embodiment in an unassembled state. [Figure 3] This is a cross-sectional view of the assembled state of the cushioning member according to the embodiment. [Figure 4] This is a cross-sectional view of the cushioning member when the first member according to the embodiment is in contact with the holder. [Modes for carrying out the invention]

[0009] The embodiments relating to this disclosure will be described below with reference to the drawings. The scale of the drawings is not necessarily accurate, and some features may be exaggerated or omitted. The buffer structure described herein is applicable to a structure (not shown) around a differential gear in an automobile or the like. The differential gear is rotatable around an axis by receiving rotational force from a power unit or transmission. The power unit includes, for example, a motor or an internal combustion engine. The differential gear is movable in the axial direction. The differential gear is connected to a shaft. The shaft is rotatably supported by bearings and retainers.

[0010] In the following explanation, the virtual axis that is the central axis of the bearing is referred to as the X-axis. The direction along the X-axis is called the +X direction. The direction opposite to the +X direction is called the -X direction. The direction away from the central axis of the bearing is called the radially outward direction. The direction toward the central axis of the bearing is called the radially inward direction.

[0011] As shown in Figure 1, the structure 10 according to this embodiment includes a shaft 30, a bearing 40, a holder 50, and a cushioning member 60. The bearing 40, the holder 50, and the cushioning member 60 constitute a cushioning structure 12.

[0012] The shaft 30 is substantially cylindrical, extending along axis XC. Axis XC is an imaginary line along the X-axis. The shaft 30 is connected to a differential gear (not shown) of structure 10. The differential gear is rotatable around axis XC by rotational force transmitted from a motor and / or transmission. The differential gear is movable along axis XC. The shaft 30 is rotatable and movable integrally with the differential gear. The shaft 30 is formed from, for example, steel for mechanical structures.

[0013] The shaft 30 has a large-diameter portion 32, a fitting portion 34, and a small-diameter portion 36. The large-diameter portion 32, the fitting portion 34, and the small-diameter portion 36 are arranged adjacent to each other in order toward the -X side. The large-diameter portion 32, the fitting portion 34, and the small-diameter portion 36 are concentric with each other. The fitting portion 34 has a smaller diameter than the large-diameter portion 32. The small-diameter portion 36 has a smaller diameter than the fitting portion 34. The large-diameter portion 32 is cylindrical and located on the +X side of the bearing 40. The large-diameter portion 32 has a larger diameter than the inner diameter of the bearing 40. The end face of the large-diameter portion 32 facing the -X side is a stepped surface 33. The fitting portion 34 is cylindrical in shape and extends from the stepped surface 33 toward the -X side. The fitting portion 34 fits with the inner ring 42. Preferably, the fitting portion 34 has a positioning structure that positions the inner ring 42 on the X axis. The positioning structure may include, for example, a snap ring. The small-diameter portion 36 is cylindrical in shape and extends toward the -X side from the end face of the fitting portion 34 facing the -X side. The small-diameter portion 36 passes through the shaft hole 56 of the retainer 50, which will be described later. Either the large diameter portion 32 or the small diameter portion 36 is coupled to a differential gear.

[0014] The bearing 40 is provided around the fitting portion 34. The bearing according to the present disclosure is a radial bearing. The bearing 40 is a rolling bearing. The bearing 40 is a ball bearing as shown in FIG. 1 and FIG. 2. The bearing according to the present disclosure is not limited to radial bearings. The bearing 40 may be an angular contact bearing. The bearing 40 may be a tapered roller bearing. The bearing 40 is held by the holder 50 in an axially movable state. The bearing 40 includes a plurality of rolling elements 46, an inner ring 42, and an outer ring 44. The rolling elements 46 of the bearing 40, which is a ball bearing, are spherical. The plurality of rolling elements 46 are arranged annularly around the shaft body 30 along the rolling surfaces of the inner ring 42 and the outer ring 44 respectively. The plurality of rolling elements 46 are positioned relative to each other by a cage (not shown) so as to maintain a predetermined interval between each other.

[0015] The inner ring 42 is an annular member that fits with the fitting portion 34. The inner ring 42 is arranged between the rolling elements 46 and the fitting portion 34. The inner ring 42 has an inner diameter portion 42a and an inner diameter side end face 42b. The inner diameter portion 42a has a cylindrical shape facing radially inward of the annular inner ring 42. The diameter of the inner diameter portion 42a is the inner diameter of the bearing 40. The inner diameter portion 42a fits with the fitting portion 34. Accordingly, the inner ring 42 can rotate integrally with the shaft body 30 around the axis XC. The inner diameter side end faces 42b face in the axial direction on the inner ring 42. The inner diameter side end face 42b facing the +X side contacts the step surface 33. The inner diameter side end face 42b facing the -X side contacts the positioning structure of the fitting portion 34. The position of the inner ring 42 in the axial direction relative to the shaft body 30 is determined by contacting the step surface 33 and the positioning structure of the fitting portion 34. Accordingly, the bearing 40 can move in the axial direction integrally with the shaft body 30.

[0016] The outer ring 44 is annular and disposed between the rolling elements 46 and the holder 50. The outer ring 44 does not contact the inner ring 42. The outer ring 44 has an outer diameter portion 44a and an outer diameter side end surface 44b. The outer diameter portion 44a is cylindrical and faces radially outward of the annular outer ring 44. The outer diameter portion 44a fits into the recess 52 of the holder 50. The outer diameter side end surface 44b faces in the axial direction of the outer ring 44.

[0017] The rolling elements 46, the inner ring 42, and the outer ring 44 are formed, for example, of carbon steel for machine structural use.

[0018] The holder 50 holds the bearing 40 so as to be movable in the axial direction. That is, the holder 50 holds the shaft body 30 via the bearing 40 so as to be movable in the axial direction. The holder 50 rotatably holds the shaft body 30 via the bearing 40. The holder 50 is formed, for example, of a steel material for machine structural use. The holder 50 has an outer surface 51, a shaft hole 56, and the recess 52. The outer surface 51 faces the +X direction. The shaft hole 56 is cylindrical and penetrates the holder 50 in a direction along the X axis. The shaft hole 56 is concentric with the shaft body 30 and the recess 52. The diameter of the shaft hole 56 is larger than that of the small diameter portion 36 and smaller than that of the recess 52. The diameter of the shaft hole 56 is preferably larger than that of the fitting portion 34. The small diameter portion 36 is disposed so as to penetrate the shaft hole 56.

[0019] The recess 52 is a bottomed hole provided between the outer surface 51 and the shaft hole 56. The recess 52 is concave with respect to the outer surface 51. The recess 52 opens at the outer surface 51. The recess 52 is cylindrical around the shaft hole 56 and has a larger diameter than the shaft hole 56. The recess 52 connects the outer surface 51 and the shaft hole 56. The bearing 40 is disposed inside the recess 52 in a state of being axially movable. The bearing 40 is preferably clearance-fitted in the recess 52.

[0020] The recess 52 has an inner wall 53 and a bottom portion 54. The inner wall 53 is a cylindrical surface facing radially inward. The inner wall 53 fits with the outer diameter portion 44a of the outer ring 44 and holds the outer ring 44. The bottom portion 54 is a planar shape facing the +X side, located between the inner wall 53 and the shaft hole 56. The bottom portion 54 connects the inner wall 53 and the shaft hole 56. The bottom portion 54 faces the outer diameter side end face 44b. The bottom portion 54 is an example of an opposing portion.

[0021] As shown in Figure 1, the cushioning member 60 is assembled between the outer ring 44 of the bearing 40 and the bottom 54 of the recess 52. The cushioning member 60 is annular around the axis XC. The cushioning member 60 is positioned so as to be sandwiched between the outer ring 44 and the bottom 54. The cushioning member 60 is spaced apart from the inner ring 42. Preferably, the cushioning member 60 has a larger diameter than the inner ring 42. Preferably, the cushioning member 60 is spaced apart from the inner wall 53. Figure 2 shows a cross-sectional view of the cushioning member 60 in an unassembled state, not assembled between the outer ring 44 and the bottom portion 54. As shown in Figure 2, the cushioning member 60 has a first member 70 and a second member 80. The cushioning member 60 further has a central hole SC and a cavity S2. The central hole SC is defined around axis XC and penetrates the cushioning member 60 in the axial direction. The central hole SC is composed of a hole portion 72c and an inner circumference portion 84, which will be described later.

[0022] The first member 70 is a metallic annular member that contacts the outer ring 44. The first member 70 has a substantially L-shaped cross-section that is upright toward the bottom 54 on the outer diameter end face 44b facing the bottom 54 side (-X side) of the outer ring 44. The first member 70 is integrally formed with the second member 80. As a result, the first member 70 can move integrally with the bearing 40 when the bearing 40 moves along the axial direction. The first member 70 is formed, for example, from steel material used for machine structures. The first member 70 has a flat plate portion 72 and a cylindrical portion 74.

[0023] The flat plate portion 72 is a round plate oriented in the axial direction. The flat plate portion 72 has a first surface 72a, a second surface 72b, and a hole 72c. The outer diameter of the flat plate portion 72 is preferably smaller than that of the recess 52. The flat plate portion 72 is preferably in surface contact with the outer ring 44. The first surface 72a faces the bottom 54 side. The second surface 72b faces the outer ring 44 side. The second surface 72b is in contact with the outer diameter end face 44b facing the -X side. The hole 72c is the radially inner edge of the annular flat plate portion 72. In other words, the hole 72c is a circular hole that penetrates the flat plate portion 72 around axis XC. The hole 72c has a larger diameter than the fitting portion 34 of the shaft body 30. Preferably, the hole 72c has a larger diameter than the inner ring 42.

[0024] The cylindrical portion 74 is a hollow cylinder extending from the radially outer edge of the flat plate portion 72 toward the bottom portion 54. The cylindrical portion 74 is integrally molded with the flat plate portion 72. The cylindrical portion 74 has a protruding surface 74a. The protruding surface 74a faces toward the bottom portion 54. The protruding surface 74a projects toward the bottom portion 54 relative to the flat plate portion 72. The radial wall thickness of the cylindrical portion 74 is greater than the axial wall thickness of the flat plate portion 72. In the assembled state in which the cushioning member 60 is fitted between the outer ring 44 and the bottom portion 54, when no external force is applied to the cushioning member 60, the cylindrical portion 74 is spaced apart from the bottom portion 54, as shown in Figure 3. When an external force acting on the -X side is applied to the bearing 40 and it moves as far as possible toward the bottom portion 43, the cylindrical portion 74 comes into contact with the bottom portion 54, as shown in Figure 4.

[0025] The second member 80 is integrally provided with the flat plate portion 72 and is an annular elastomer that contacts the bottom portion 54. In the unassembled state, as shown in Figure 2, the second member 80 has a substantially U-shaped cross-section that stands upright toward the bottom portion 54 on the first surface 72a of the flat plate portion 72. In the unassembled state, the second member 80 protrudes toward the bottom portion 54 than the cylindrical portion 74. In the assembled state, the second member 80 is sandwiched between the flat plate portion 72 and the bottom portion 54, as shown in Figure 3. When the bearing 40 moves along the axial direction, the second member 80 is deformable to expand and contract in accordance with the movement of the bearing 40. At this time, the second member 80 can move the first member 70 in the axial direction in accordance with the deformation of the second member 80. The second member 80 is preferably made of, for example, nitrile rubber (NBR), fluororubber (FKM), acrylic rubber (ACM), silicone rubber, or urethane rubber. The second member 80 has a base portion 82, an inner circumference portion 84, and an outer circumference portion 86. The second member 80 further has a hollow portion S1.

[0026] As shown in Figures 2 to 4, the base portion 82 is a round plate-like structure provided on the first surface 72a, spaced radially apart from the cylindrical portion 74. The base portion 82 is in surface contact with the first surface 72a. The base portion 82 has an inner edge portion 82c and an outer edge portion 82d. The inner edge portion 82c is the radially inner edge of the base portion 82. The outer edge portion 82d is the radially outer edge of the base portion 82. The axial thickness of the base portion 82 is preferably smaller than the radial thickness of the inner circumference portion 84 and the outer circumference portion 86, respectively. The base portion 82 is preferably bonded to the flat plate portion 72. The base portion 82 may be vulcanized and bonded to the flat plate portion 72. The base portion 82 may be bonded to the flat plate portion 72 with an adhesive.

[0027] The inner circumference portion 84 is a hollow, substantially cylindrical shape that extends from the inner edge portion 82c of the base portion 82 toward the bottom portion 54. In the unassembled state, the inner circumference portion 84 protrudes toward the bottom portion 54 side of the cylindrical portion 74, as shown in Figure 2. The axial length between the tip of the inner circumference portion 84 toward the bottom portion 54 and the tip of the cylindrical portion 74 toward the bottom portion 54 in the unassembled state is called the first protrusion length D1. Preferably, the first protrusion length D1 of the inner circumference portion 84 toward the cylindrical portion 74 is greater than the radial wall thickness of the inner circumference portion 84. In the assembled state, the inner circumference 84 contacts the bottom 54 at its tip on the bottom 54 side, as shown in Figures 3 and 4.

[0028] In the unassembled state, the diameter of the inner circumference 84 increases from the base 82 side to the bottom 54 side, as shown in Figure 2. In other words, in the unassembled state, the inner circumference 84 inclins radially outward in cross-sectional view from the base 82 side to the bottom 54 side. As a result, when the inner circumference 84 comes into contact with the bottom 54 in the assembled state and is pressed toward the bottom 54 side and undergoes compression deformation, it tends to bend into a V-shape, bending toward the central hole SC side, as shown in Figures 3 and 4. In other words, in the assembled state, the inner circumference 84 tends to bend into a V-shape on the side opposite to the hollow portion S1 side relative to the inner circumference 84.

[0029] The outer periphery 86 is a hollow, substantially cylindrical shape that extends from the outer edge 82d of the base 82 toward the bottom 54. In the unassembled state, the outer periphery 86 protrudes toward the bottom 54 side of the cylindrical portion 74, as shown in Figure 2. The axial length between the tip of the outer periphery 86 toward the bottom 54 side and the tip of the cylindrical portion 74 toward the bottom 54 side in the unassembled state is called the second protrusion length D2. Preferably, the second protrusion length D2 of the outer periphery 86 toward the cylindrical portion 74 is greater than the radial wall thickness of the outer periphery 86. In the assembled state, the outer peripheral portion 86 contacts the bottom portion 54 at its tip on the bottom portion 54 side, as shown in Figures 3 and 4.

[0030] In the unassembled state, the outer circumference 86 is radially separated from the cylindrical portion 74. A cavity S2 is defined between the outer circumference 86 and the cylindrical portion 74. In the assembled state, it is preferable that the outer circumference 86 is separated from the cylindrical portion 74. When the cylindrical portion 74 is in contact with the bottom portion 54, it is even more preferable that the outer circumference 86 is separated from the cylindrical portion 74. The radial width of the cavity S2 is preferably greater than the radial wall thickness of the outer periphery 86. In other words, the radial separation distance between the cylindrical portion 74 and the outer periphery 86 is preferably greater than the radial wall thickness of the outer periphery 86.

[0031] In the unassembled state, the diameter of the outer circumference 86 decreases as you move from the base 82 side to the bottom 54 side, as shown in Figure 2. In other words, in the unassembled state, the outer circumference 86 inclins radially inward in cross-sectional view as you move from the base 82 side to the bottom 54 side. As a result, when the outer circumference 86 comes into contact with the bottom 54 in the assembled state and is pressed toward the bottom 54 side and undergoes compression deformation, it tends to bend into a V-shape, bending toward the cylindrical portion 74 side, as shown in Figures 3 and 4. In other words, in the assembled state, the outer circumference 86 tends to bend into a V-shape on the side opposite to the hollow portion S1 side relative to the outer circumference 86.

[0032] The hollow portion S1 is a space formed within the cross-section of the second member 80. Specifically, the hollow portion S1 is defined by at least the base portion 82, the inner circumference portion 84, and the outer circumference portion 86. In other words, the hollow portion S1 is surrounded by the base portion 82, the inner circumference portion 84, and the outer circumference portion 86. As shown in Figure 3, in the assembled state where no external force is applied to the buffer member 60, the hollow portion S1 is further defined by the bottom portion 54.

[0033] As shown in Figure 4, when an external force is applied to the cushioning member 60 via the bearing 40 so that the cylindrical portion 74 and the bottom portion 54 come into contact, the inner circumference 84 and the outer circumference 86 bend into a V-shape, thereby maintaining the hollow portion S1 within the second member 80 without collapsing. In other words, the second member 80 can be deformed while maintaining the hollow portion S1 when the bearing 40 moves along the axial direction.

[0034] When the external force on the bearing 40 and the cushioning member 60 is removed from the state in which the cylindrical portion 74 and the bottom portion 54 are in contact, a restoring force acts on the inner circumference 84 and the outer circumference 86 due to the compressive deformation of the elastomer. Due to this restoring force, the inner circumference 84 and the outer circumference 86 are restored to a state that is more axially extended than when the cylindrical portion 74 and the opposing portion are in contact (see Figure 4) (see Figure 3). At this time, the second member 80 moves so as to press the first member 70 toward the bearing 40. At this time, the bearing 40 moves as if being pushed out by the first member 70. In other words, when the bearing 40 moves along the axial direction, the second member 80 can deform to expand and contract in accordance with the movement of the bearing 40 while maintaining the hollow portion S1.

[0035] (Mechanism of Action and Effects) Next, the operation and effects of the cushioning structure 12 having the cushioning member 60 of the embodiment will be described. The buffer member 60 has a first member 70. When the differential gear switches between powered or regenerative braking in the state where the cylindrical portion 74 and the bottom portion 54 shown in Figure 4 are in contact, the load torque associated with the switching is transmitted to the buffer member 60 via the bearing 40. At this time, because the buffer member 60 has the first member 70, the cylindrical portion 74 of the first member 70 can absorb the load torque and suppress the load on the second member 80. This makes it possible to suppress deterioration or damage to the second member 80 caused by the load torque associated with the switching of gear motion. In other words, because the buffer member 60 has the first member 70, even when load torque associated with the switching of gear motion is transmitted, the buffer performance of the second member 80 is less likely to deteriorate.

[0036] The cushioning member 60 further comprises a second member 80. The second member 80, made of elastomer, is capable of absorbing shocks caused by the gap between the bearing 40 and the bottom 54, and has excellent cushioning performance. The cushioning performance of the cushioning member 60 having the second member 80 is less affected by the dimensional accuracy of the bearing 40 and the recess 52. The second member 80 has a hollow portion S1 surrounded by a base portion 82, an inner circumference portion 84, and an outer circumference portion 86. When the bearing 40 moves along the axial direction, the second member 80 is deformable to expand and contract in accordance with the movement of the bearing 40 while maintaining the hollow portion S1. If the second member compresses and deforms in a way that crushes the hollow portion S1 when the bearing 40 moves along the axial direction, the axial component of the restoring force generated due to the compressive deformation of the second member will increase. In this case, the restoring force of the second member may deform the first member 70, the outer ring 44, and the holder 50. In this case, the resulting gap may worsen the impact characteristics of the structure. Furthermore, if the second member compresses and deforms in a way that crushes the hollow portion S1, the cushioning performance of the second member may deteriorate.

[0037] On the other hand, the second member 80 of the embodiment is deformable to expand and contract in accordance with the movement of the bearing 40 while maintaining the hollow portion S1. Specifically, the inner circumference 84 and the outer circumference 86 each bend in a V-shape on the side opposite to the hollow portion S1 when assembled. In this case, the restoring force generated due to the compressive deformation of the second member 80 is less likely to deform the first member 70, the outer ring 44, and the holder 50. In this case, the cushioning structure 12 is less likely to worsen the impact characteristics of the structure 10. Also, in this case, the cushioning performance of the second member 80 is less likely to deteriorate. Therefore, the cushioning structure 12 having the cushioning member 60 can effectively suppress impacts caused by the axial gap between the bearing 40 and the holder 50. In particular, the cushioning structure 12, which defines the hollow portion S1 with the base portion 82, the inner circumference portion 84, and the outer circumference portion 86, can effectively suppress impacts caused by the axial gap between the bearing 40 and the retainer 50 with a simple configuration.

[0038] In the unassembled state, the inner circumference 84 is inclined radially outward as it moves from the base 82 side to the bottom 54 side. In this case, the inner circumference 84 is prone to bending in a V-shape on the side opposite to the hollow portion S1 in the assembled state. Therefore, the cushioning member 60 of the cushioning structure 12 makes it possible to easily deform the inner circumference 84 so that it expands and contracts in accordance with the movement of the bearing 40 while maintaining the hollow portion S1.

[0039] In the unassembled state, the outer circumference 86 is inclined radially inward as it moves from the base 82 side to the bottom 54 side. In this case, the outer circumference 86 is prone to bending in a V-shape on the side opposite to the hollow portion S1 in the assembled state. Therefore, the cushioning member 60 of the cushioning structure 12 makes it easier to deform the outer circumference 86 so that it expands and contracts in accordance with the movement of the bearing 40 while maintaining the hollow portion S1.

[0040] When the cylindrical portion 74 is in contact with the bottom portion 54, the outer circumference 86 is separated from the cylindrical portion 74. If the outer circumference deforms to come into contact with the cylindrical portion 74 when the cylindrical portion 74 is in contact with the bottom portion 54, it will increase the axial component of the restoring force associated with the compressive deformation of the outer circumference. In this case, the restoring force of the second member may deform the first member 70, the outer ring 44, and the holder 50. In addition, in this case, the cushioning performance of the second member may deteriorate. On the other hand, the distance between the cylindrical portion 74 and the outer peripheral portion 86 in the unassembled state is greater than the wall thickness of the outer peripheral portion 86. In this case, the outer peripheral portion 86 is likely to be separated from the cylindrical portion 74 when the cylindrical portion 74 comes into contact with the bottom portion 54. In this case, the increase in the axial component of the restoring force due to the compressive deformation of the outer peripheral portion 86 is suppressed. Therefore, the cushioning member 60 of the cushioning structure 12 can suppress the deterioration of the cushioning performance of the cushioning structure 12 due to contact between the cylindrical portion 74 and the bottom portion 54.

[0041] The first protrusion length D1 of the inner circumference 84 relative to the cylindrical portion 74 is greater than the wall thickness of the inner circumference 84. In this case, the inner circumference 84 is easily deformed to bend on the opposite side from the hollow portion S1 when assembled. Therefore, the cushioning member 60 of the cushioning structure 12 makes it easier to deform the inner circumference 84 so that it expands and contracts in accordance with the movement of the bearing 40 while maintaining the hollow portion S1.

[0042] The second protrusion length D2 of the outer circumference 86 relative to the cylindrical portion 74 is greater than the wall thickness of the outer circumference 86. In this case, the outer circumference 86 is easily deformed to bend on the opposite side from the hollow portion S1 when assembled. Therefore, the cushioning member 60 of the cushioning structure 12 makes it easier to deform the outer circumference 86 so that it expands and contracts in accordance with the movement of the bearing 40 while maintaining the hollow portion S1.

[0043] The thickness of the base portion 82 is smaller than the thickness of the inner circumference portion 84 and the outer circumference portion 86, respectively. In this case, the inner circumference portion 84 and the outer circumference portion 86 are easily deformed to bend on the opposite side from the hollow portion S1 when assembled. Therefore, the cushioning member 60 of the cushioning structure 12 makes it easier to further deform the inner circumference portion 84 and the outer circumference portion 86 so that they expand and contract in accordance with the movement of the bearing 40 while maintaining the hollow portion S1.

[0044] The base portion 82 is bonded to the flat plate portion 72. In this case, the handling of the cushioning member 60 is improved. Therefore, the cushioning member 60 of the cushioning structure 12 can improve the assembly of the cushioning member 60 in the cushioning structure 12. Furthermore, if the base portion 82 is not bonded to the flat plate portion 72, there is a risk that when the second member 80 is compressed, the base portion 82 may deform in such a way that it lifts up from the flat plate portion 72 toward the bottom portion 54. In this case, there is a risk that the second member 80 may be compressed and deform in such a way that it crushes the hollow portion S1. Also, in this case, there is a risk that the posture of the second member 80 in the assembled state will become unstable. In this case, there is a risk that the cushioning performance of the cushioning structure 12 will deteriorate. On the other hand, since the base portion 82 of the embodiment is bonded to the flat plate portion 72, when the second member 80 is compressed and deformed, it is possible to suppress the deformation of the base portion 82 so that it lifts up from the flat plate portion 72. This makes it possible to further suppress the deterioration of the cushioning performance of the cushioning structure 12.

[0045] As described above, an embodiment of the present invention has been explained as an example, but the present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements are possible within the scope of the technical idea of ​​the present invention.

[0046] The structure around the differential gear to which the damping structure 12 of the embodiment is applied is provided in an automobile. However, the application of the vibration isolation structure according to this disclosure is not limited to automobiles. The vibration isolation structure according to this disclosure may be applied to mobility in general, including construction machinery and agricultural machinery. [Explanation of Symbols]

[0047] 10 Structure 12 Buffer structure 30 Axis Body 40 bearings 50 Holder 52 recess 54 Bottom (an example of opposing parts) 60 Cushioning material 70 First component 72 Flat plate part 74 Cylindrical section 80 Second member 82 Base 82c Inner edge 82d Outer edge 84 Inner circumference 86 Outer perimeter SC center hole S1 Hollow part S2 cavity

Claims

1. A bearing having an outer ring, A holder that holds the outer ring so as to be movable in the axial direction, the holder having a portion facing the outer ring in the axial direction, An annular cushioning member around an axis, which is assembled in a state sandwiched between the outer ring and the opposing portion, A first metal component, The flat plate portion that contacts the outer ring, A cylindrical portion extending from the flat plate portion toward the opposing portion, A first member having, A second member made of elastomer, which is provided so as to be sandwiched between the flat plate portion and the opposing portion, and which has a hollow portion, is deformable to expand and contract in accordance with the movement of the bearing while maintaining the hollow portion when the bearing moves along the axial direction, A cushioning member having, A buffer structure having the following characteristics.

2. The second member is, A base portion that is spaced apart from the cylindrical portion and in surface contact with the flat plate portion, An inner circumferential portion extending from the radially inner edge of the base toward the opposing portion and in contact with the opposing portion, An outer peripheral portion extending from the radially outer edge of the base toward the opposing portion and in contact with the opposing portion, It has, The buffer structure according to claim 1, wherein the hollow portion is surrounded by the base portion, the inner circumferential portion, and the outer circumferential portion.

3. The cushioning structure according to claim 2, wherein the inner circumference is bent in a V-shape on the side opposite to the hollow portion when assembled.

4. The cushioning structure according to claim 2 or 3, wherein the inner circumference is inclined radially outward as it progresses from the base side to the opposing side when not assembled.

5. The cushioning structure according to any one of claims 2 to 4, wherein the outer periphery is bent in a V-shape on the side opposite to the hollow portion when assembled.

6. The cushioning structure according to any one of claims 2 to 5, wherein the outer circumference is inclined radially inward as it progresses from the base side to the opposing side when not assembled.

7. The buffer structure according to any one of claims 2 to 6, wherein when the cylindrical portion is in contact with the opposing portion, the outer peripheral portion is spaced apart from the cylindrical portion.

8. The cushioning structure according to claims 2 to 7, wherein the distance between the cylindrical portion and the outer peripheral portion in the unassembled state is greater than the wall thickness of the outer peripheral portion.

9. In the unassembled state, The inner circumference protrudes more than the cylindrical portion toward the opposing portion. The cushioning structure according to claims 2 to 8, wherein the axial projection length of the inner circumference relative to the cylindrical portion is greater than the wall thickness of the inner circumference.

10. In the unassembled state, The outer circumference protrudes more than the cylindrical portion toward the opposing portion, The cushioning structure according to claims 2 to 9, wherein the axial projection length of the outer circumference relative to the cylindrical portion is greater than the wall thickness of the inner circumference.

11. The cushioning structure according to claims 2 to 10, wherein the thickness of the base is smaller than the thickness of the inner circumference and the outer circumference, respectively.

12. The cushioning structure according to claims 2 to 11, wherein the base portion is bonded to the flat plate portion.

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