Vibration isolation structure

Abstract

To suppress the transmission of vibrations from rolling bearings placed between the shaft and the support body using a simple configuration, while also suppressing the misalignment of the rotation center of the rolling bearings. [Solution] A vibration damping structure 12 comprising: a shaft 20; a rolling bearing 40 having an inner ring 42 which fits with the shaft 20 and has an inner end face 42b, an outer ring 44 which has an outer end face 44b which faces axially, an outer diameter portion 44a which faces radially outward, and an outer corner portion 44c which connects the outer diameter portion 44a and the outer end face 44b; a support 30 having a fitting portion 34 which fits with the outer ring 44 and an opposing portion 36 which faces the inner end face 42b or the outer end face 44b; and an annular vibration damping member 50 which is disposed between the fitting portion 34, the opposing portion 36 and the outer corner portion 44c and applies elastic force to the outer ring 44 which acts radially and axially upon contact with the outer corner portion 44c.

Description

Technical Field

[0001] The present invention relates to a vibration isolation structure.

Background Art

[0002] There is known a bearing device around a drive shaft of an automobile or the like, in which an elastic body (elastomer) is provided around a rolling bearing (for example, Patent Document 1). The drive shaft transmits power from a power device or a transmission to a wheel tire. The power device includes, for example, a motor or an internal combustion engine. In such a bearing device, the elastic body provided around the rolling bearing functions as a vibration isolation member that attenuates vibrations caused by the rotation of the rolling bearing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] One of the factors of vibrations caused by the rotation of a rolling bearing is the deviation of the rotation center of the rolling bearing. One of the factors of the deviation of the rotation center of the rolling bearing is the internal clearance between the rolling elements of the rolling bearing and the outer and inner rings. When a rolling bearing is installed such that the axial direction of the rolling bearing is along the horizontal direction, as in the structure around a drive shaft, due to the action of gravity, a deviation of the internal clearance occurs between the vertically upper side and the vertically lower side, increasing the deviation of the rotation center. One method for reducing the internal clearance of a rolling bearing is to apply an external force to the outer or inner ring that presses it against the rolling elements in the axial direction. When an elastomer vibration-damping member is pressed axially against the outer ring of the rolling elements, the internal clearance of the rolling bearing can be reduced, but only the axial vibrations caused by the rolling bearing are suppressed. Therefore, when an elastomer vibration-damping member is pressed axially against the outer ring of the rolling elements, if radial vibrations caused by the rolling bearing are to be suppressed, it is necessary to place an additional vibration-damping member radially adjacent to the bearing.

[0005] The present disclosure aims to provide a vibration-damping structure that can suppress the transmission of vibrations from a rolling bearing placed between a shaft and a support body with a simple configuration, while also suppressing the displacement of the rotation center of the rolling bearing. [Means for solving the problem]

[0006] A part of this disclosure is a shaft body extending in the axial direction, It is a rolling bearing, An inner ring that fits with the shaft body, having an inner end face facing axially, An outer ring arranged radially outward with respect to the inner ring, The outer end face facing the axial direction, The outer diameter portion facing radially outward, The outer corner portion connecting the outer diameter portion and the outer end face, An outer ring having, A rolling bearing having, A support for the aforementioned rolling bearing, A fitting portion that engages with the outer ring, The inner end face or the opposing portion facing the outer end face, A support having, An annular vibration-damping member is positioned between the fitting portion, the opposing portion, and the outer corner portion, and applies elastic force to the outer ring in the radial and axial directions in conjunction with contact with the outer corner portion. It is a vibration-damping structure that has [the following characteristics]. [Effects of the Invention]

[0007] According to this disclosure, it is possible to suppress the transmission of vibrations from a rolling bearing placed between a shaft and a support body with a simple configuration, while also suppressing the displacement of the rotation center of the rolling bearing. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view of a vibration-damping structure according to an embodiment. [Figure 2] This is a cross-sectional view of a vibration-damping member according to an embodiment. [Figure 3] This is a cross-sectional view showing a modified example of the vibration-damping member according to the embodiment. [Figure 4] This is a cross-sectional view showing a modified example of the bearing according to the embodiment. [Figure 5] This is a cross-sectional view showing a modified example of the bearing and vibration-damping member according to the embodiment. [Figure 6] This is a cross-sectional view showing a modified example of the vibration isolation structure according to the embodiment. [Figure 7] This is a cross-sectional view showing a modified example of the vibration isolation structure according to the embodiment. [Figure 8] This is a cross-sectional view showing a modified example of the vibration-damping member according to the embodiment. [Figure 9] This is a cross-sectional view showing a modified example of the vibration isolation structure according to the embodiment. [Figure 10] This is a cross-sectional view showing a modified example of the vibration isolation structure according to the embodiment. [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 vibration isolation structure described herein is applicable to a structure (not shown) around a rotating shaft in an automobile or the like. The rotating shaft is, for example, a drive shaft located around a power unit or transmission. The power unit includes, for example, a motor or an internal combustion engine.

[0010] In the following description, the direction along the axial direction of the rolling bearing is referred to as the X direction. The direction in which the rolling bearing inserted into the concave fitting portion that opens in the axial direction faces the bottom surface of the fitting portion is referred to as the -X direction. The direction opposite to the -X direction is referred to as the +X direction. Further, the direction away from the central axis of the rolling bearing is referred to as the radially outer side. The direction toward the central axis of the rolling bearing is referred to as the radially inner side.

[0011] As shown in FIG. 1, the structure 10 according to the embodiment includes a shaft body 20, a bearing 40, a support body 30, a fastener 70, and a vibration isolator 50. The shaft body 20, the bearing 40, the support body 30, and the vibration isolator 50 constitute a vibration isolation structure 12.

[0012] The shaft body 20 has a columnar shape that extends uniformly along the axis XC. The axis XC is a virtual center line along the X-axis direction. The shaft body 20 has a side surface portion 22. The shaft body 20 is connected to a drive unit (not shown). The drive unit includes a motor and / or a transmission. The shaft body 20 is rotatable about the axis XC by the drive unit. The shaft body 20 is arranged at a predetermined position with respect to the bearing 40 or the support body 30 described later by known positioning means (not shown).

[0013] The bearing 40 is a rolling bearing provided around the shaft body 20. The rolling bearing according to the present disclosure is a radial bearing. The bearing 40 is a ball bearing. The rolling bearing according to the present disclosure is not limited to a ball bearing as long as it is a radial bearing and a rolling bearing. The bearing may be a spherical roller bearing. The bearing 40 is arranged and supported inside a hole portion 32 of the support body 30 described later. The bearing 40 has a plurality of rolling elements 40a, an inner ring 41, and an outer ring 44. The rolling elements 40a of the bearing 40, which is a ball bearing, are spherical. The plurality of rolling elements 40a are arranged annularly around the shaft body 20 along the rolling surfaces 43 and 47 of the inner ring 41 and the outer ring 44 described later.

[0014] The inner ring 41 is annular in shape and fits with the shaft 20. The inner ring 41 is positioned between the rolling element 40a and the shaft 20. The inner ring 41 has an inner diameter portion 41a, an inner end face 42, and a first rolling surface 43. The inner diameter portion 41a is cylindrical and faces radially inward of the annular inner ring 41. The inner diameter portion 41a fits with the side portion 22 of the shaft body 20. As a result, the inner ring 41 can rotate around the axis XC as a single unit with the shaft body 20. The inner end face 42 extends radially outward from both axial ends of the inner diameter portion 41a. The inner end face 42 has an inner end face 42a and an inner end face 42b. The inner end face 42a faces the +X side. The inner end face 42b faces the -X side. The first rolling surface 43 is formed radially outward from the inner diameter portion 41a and is annular in shape facing radially outward. In the ball bearing bearing 40, the first rolling surface 43 is approximately semicircular in shape along the surface of the spherical rolling element 40a in the cross-sectional view shown in Figure 1.

[0015] The outer ring 44 is annular in shape, positioned radially outward from the inner ring 41, with the rolling elements 40a in between. The outer ring 44 is positioned between the rolling elements 40a and the support 30. The outer ring 44 does not come into contact with the inner ring 41. The outer ring 44 has an outer diameter portion 44a, an outer end face 45, an outer corner portion 46, and a second rolling surface 47. The outer diameter portion 44a is cylindrical and faces radially outward from the annular outer ring 44. The outer diameter portion 44a fits into the hole 32 of the support 30. The outer end face 45 extends radially inward from both axial ends of the outer diameter portion 44a. The outer end face 45 has an outer end face 45a and an outer end face 45b. The outer end face 45a faces the +X side. The outer end face 45b faces the -X side. The outer corner portion 46 is annular, connecting the outer diameter portion 44a and the outer end face 45. The outer corner portion 46 has a rounded curved shape. The outer corner portion 46 has an outer corner portion 46a and an outer corner portion 46b. The outer corner portion 46a faces the +X side. The outer corner portion 46b faces the -X side. The second rolling surface 47 is formed radially inward from the outer diameter portion 44a and is annular in orientation radially inward. In the ball bearing bearing 40, the second rolling surface 47 is approximately semicircular in shape, following the surface of the spherical rolling element 40a in the cross-sectional view shown in Figure 1.

[0016] The support 30 supports the shaft 20 via the bearing 40. The support 30 has an outer surface 30a, a hole 32, and a fastener 70. The outer surface 30a faces the +X direction.

[0017] The hole 32 is cylindrical and penetrates the support 30 in the X direction. The hole 32 has a large diameter portion 34, a small diameter portion 35, a stepped surface 36, and a first corner portion 38. The large-diameter portion 34 is a cylindrical hole that opens on the outer surface 30a. The large-diameter portion 34 fits with the outer shape 44a of the bearing 40. The large-diameter portion 34 is an example of a fitting portion. The support 30 supports the bearing 40 with the large-diameter portion 34 of the hole 32. The small-diameter portion 35 is a cylindrical hole formed on the side further from the outer surface 30a than the large-diameter portion 34. The small-diameter portion 35 opens at a stepped surface 36, which will be described later. The small-diameter portion 35 is concentric with the large-diameter portion 34. The diameter of the small-diameter portion 35 is larger than the diameter of the shaft 20 and smaller than the diameter of the large-diameter portion 34. The small-diameter portion 35 leaves the inner end face 42b of the bearing 40 fitted into the large-diameter portion 34 open. The stepped surface 36 is planar, connecting the large-diameter portion 34 and the small-diameter portion 35. That is, the stepped surface 36 is provided between the large-diameter portion 34 and the small-diameter portion 35. The stepped surface 36 faces the +X side. When the bearing 40 is positioned in the hole portion 32, the stepped surface 36 faces the outer end face 45b of the outer ring 44. The stepped surface 36 is an example of the first opposing portion. In the vibration isolation structure 12 of the structure 10, the stepped surface 36 overlaps only with the outer end face 45 in the axial direction. That is, the stepped surface 36 does not face the inner end face 42b of the inner ring 41. The first corner 38 is an annular shape connecting the large-diameter portion 34 and the stepped surface 36. The first corner 38 is defined between the large-diameter portion 34 and the stepped surface 36. The first corner 38 may also be a rounded curved surface.

[0018] The fastener 70 is provided separately from the support 30 on the outer surface 31. The fastener 70 is annular and plate-shaped. The fastener 70 is assembled to the support 30 by fastening means (not shown). The fastening means are, for example, bolts and nuts. The fastener 70 prevents the bearing 40, which is placed in the hole 32, from falling out of the hole 32. The fastener 70 has a central hole 72 and a locking surface 76. A second corner 78 is defined between the fastener 70 and the support 30. The central hole 72 is cylindrical and faces radially inward from the annular fastener 70. The diameter of the central hole 72 is larger than the diameter of the shaft 20 and smaller than the diameter of the large-diameter portion 34. The locking surface 76 faces the -X side. When the bearing 40 is positioned in the hole 32, the locking surface 76 faces the outer end face 45a of the outer ring 44. The locking surface 76 is an example of a second opposing surface. The locking surface 76 overlaps only with the outer end face 45 in the axial direction. The locking surface 76 may also face the inner end face 42a of the inner ring 41. That is, the locking surface 76 may also overlap with the inner end face 42 in the axial direction. The second corner portion 78 is a corner-shaped space defined between the locking surface 76 and the large-diameter portion 34 of the hole 32.

[0019] The vibration-damping member 50 is annular in shape and is positioned between the large-diameter portion 34 of the support 30, the stepped surface 36, and the outer corner portion 46 of the bearing 40. Specifically, the vibration-damping member 50 is positioned in the first corner portion 38 of the hole portion 32 in which the bearing 40 is located. As shown in Figure 2, the vibration-damping member 50 has a core material 52 and a main body portion 60.

[0020] The core material 52 is an annular shape formed around the axis XC. The core material 52 has higher rigidity than the main body 60. The core material 52 is preferably made of metal. The core material 52 is preferably made of rolled steel (SPCC, etc.) or stainless steel.

[0021] The main body portion 60 is an annular shape formed around the core material 52, with the core material 52 as the base material. The main body portion 60 is made of an elastomer or thermoplastic resin. The elastomer is preferably, for example, EPDM (ethylene propylene diene rubber), acrylic rubber (ACM), nitrile rubber (NBR), or fluororubber (FKM).

[0022] The cross-sectional shape of the main body 60 is a pentagonal shape formed by chamfering one of the corners of a rectangular shape, as shown in Figure 2. The main body 60 has an outer circumference 61, an inner circumference 62, a bottom 63, a tip 66, and an inclined portion 68. The outer periphery 61 is a cylindrical surface facing radially outward from the main body 60. The outer periphery 61 is in contact with the large-diameter portion 34 of the support 30. The inner circumference 62 is a cylindrical surface facing radially inward from the main body 60. The axial length of the inner circumference 62 is shorter than that of the outer circumference 61. The bottom portion 63 connects the ends of the outer circumference portion 61 and the inner circumference portion 62 in the -X direction. In the vibration isolation structure 12, the bottom portion 63 connects the ends of the outer circumference portion 61 and the inner circumference portion 62 on the -X side. The bottom portion 63 faces the -X side. The bottom portion 63 is in contact with the stepped surface 36 of the support 30. The tip portion 66 extends radially inward from the +X end of the outer circumference portion 61. The tip portion 66 faces the +X side. The radial length of the tip portion 66 is shorter than that of the base portion 63. The inclined portion 68 is an inclined surface that connects the tip portion 66 and the inner circumference portion 62. In cross-sectional view, the inclined portion 68 is inclined linearly with respect to the axial direction. The inclined portion 68 faces radially inward and towards the +X side. The inclined portion 68 is in contact with the outer corner portion 46b of the bearing 40. The inclined portion 68 is an example of an opposing surface.

[0023] The vibration-damping member 50 positioned at the first corner 38 causes the main body 60 to elastically deform upon contact with the outer corner 46 of the bearing 40. The vibration-damping member 50 transmits the elastic force generated by the elastic deformation of the main body 60 to the outer ring 44 via the inclined portion 68 and the outer corner 46. The elastic force transmitted from the outer corner 46 to the outer ring 44 is directed radially inward and towards the +X side. In other words, the vibration-damping member 50 imparts elastic forces acting radially and axially to the outer ring 44 upon contact with the outer corner 46.

[0024] Furthermore, the vibration-damping member 50 does not need to have a core material 52, as long as it can impart elastic force to the outer ring 44 acting radially and axially in conjunction with contact with the outer corner portion 46.

[0025] The vibration-damping member according to this disclosure is not limited to the pentagonal cross-sectional shape described above, as long as it can impart elastic forces acting radially and axially to the outer ring 44 in connection with the outer corner portion 46. The vibration-damping member according to this disclosure may have a hexagonal cross-sectional shape, for example, as shown in Figure 3, for the vibration-damping member 250. Specifically, the vibration-damping member 250 has an inclined portion 264 in addition to the vibration-damping member 50. The inclined portion 264 is a straight inclined surface in cross-sectional view, such as a chamfered corner connecting the outer circumference 61 and bottom portion 63 of the vibration-damping member 50. The vibration-damping member 250 having the inclined portion 264 can avoid being positioned in an unstable position due to interference with the first corner portion 38, even when the first corner portion 38 is a rounded curved surface. The vibration-damping member according to this disclosure does not need to have opposing surfaces such as the inclined portion 68, as long as it can impart elastic forces to the outer ring 44 acting radially and axially in connection with the outer corner portion 46. The cross-sectional shape of the vibration-damping member according to this disclosure may be a thick, arc-shaped curve that follows the outer corner portion 46 of the bearing 40. The cross-sectional shape of the vibration-damping member according to this disclosure may also be a solid circle.

[0026] (Mechanism of Action and Effects) Next, the operation and effects of the vibration isolation structure 12 of the first embodiment will be described. The vibration isolation member 50 of the vibration isolation structure 12 applies elastic force to the outer ring 44 of the bearing 40 in the radially inward and axially (+X side) direction as a result of contact between the inclined portion 68 and the outer corner portion 46. The axial component of the elastic force generated as a result of contact between the inclined portion 68 and the outer corner portion 46 moves the outer ring 44 to the +X side. The radial component of the elastic force acts like a pressure directed radially inward on the annular outer ring 44. The inner ring 41 of the bearing 40 is in contact only with the rolling elements 40a and the shaft 20. Therefore, the internal clearance of the bearing 40 is reduced as the elastic force is applied to the outer ring 44 from the vibration isolation member 50. In particular, the internal clearance of the bearing 40 is reduced when a load directed toward the -X side is applied to the inner ring 41 through the shaft 20 and the outer ring 44 is subjected to elastic force. As the internal clearance of the bearing 40 decreases, the displacement of the center of rotation of the bearing 40 decreases. Furthermore, the vibration-damping member 50 of the vibration-damping structure 12 is in contact with the outer ring 44 of the bearing 40 at the inclined portion 68. Therefore, the vibration-damping member 50 can suppress both the radial and axial components of vibrations caused by the bearing 40. Therefore, the vibration isolation structure 12 can suppress the transmission of vibrations from the bearing 40, which is placed between the shaft 20 and the support 30, with a simple configuration, while also suppressing the displacement of the bearing 40's rotation center.

[0027] The vibration-damping member 50 comprises a core material 52 and a main body portion 60. Therefore, the vibration-damping member 50 of the vibration-damping structure 12 can increase the elastic force associated with the elastic deformation of the main body portion 60 and effectively apply the elastic force to the bearing 40.

[0028] The vibration-damping member 50 has an inclined portion 68. Therefore, the vibration-damping member 50 of the vibration-damping structure 12 can more effectively apply the elastic force associated with the elastic deformation of the vibration-damping member 50 to the bearing 40.

[0029] The outer ring of the bearing according to this disclosure may have a chamfered portion 347, as shown in the bearing 340 of the vibration-damping structure 312 in Figure 4. The chamfered portion 347 is formed by chamfering the corner formed when the outer diameter portion 44a and the outer end face 45 meet perpendicularly. The chamfered portion 347 is inclined linearly with respect to the axial direction in cross-sectional view. The chamfered portion 344d connects the outer diameter portion 44a and the outer end face 45. That is, the outer corner portion 346 of the bearing 340 is the chamfered portion 347. The chamfered portion 347 faces radially outward and toward the -X side. In this case, the bearing 340 of the vibration-damping structure 312 can effectively apply the elastic force provided by the vibration-damping member 50 to the outer ring 44 as an external force acting in both the radial and axial directions.

[0030] The bearing and vibration-damping member according to this disclosure may be such that the bearing 440 and the vibration-damping member 450 are integrally fixed, as shown in the vibration-damping structure 412 in Figure 5. Specifically, the vibration-damping member 450 may be integrally provided with the outer corner portion 46 of the bearing 440. In this case, the inclined portion 68 of the vibration-damping member 450 is bonded to the outer corner portion 46 with an adhesive, for example. In this case, the bearing 440 and the vibration-damping member 450 can be handled together during the assembly of the vibration-damping structure 412. Therefore, the vibration-damping structure 412 having the bearing 440 and the vibration-damping member 450 can improve the ease of assembly of the vibration-damping structure 412.

[0031] The first corner portion of the present disclosure may be a concealed groove 538, as shown in the vibration-damping structure 512 in Figure 6. The concealed groove 538 is an annular groove that opens concavely to the large-diameter portion 34. The concealed groove 538 has a groove wall that is substantially flush with the stepped surface 36. In other words, the concealed groove 538 is formed between the large-diameter portion 34 and the stepped surface 36. In this case, the vibration isolation structure 512 allows the vibration isolation member 550 to be placed in the recessed groove 538. Furthermore, the vibration isolation member 550 of the vibration isolation structure 512 can be made larger by the width of the recessed groove 538 compared to the vibration isolation member 50 of the vibration isolation structure 12.

[0032] The vibration-damping member according to this disclosure may be positioned between the second corner 78 and the outer corner 46a of the bearing 40, as shown in the vibration-damping member 650 of the vibration-damping structure 612 in Figure 7. Specifically, the vibration-damping member 650 is positioned between the large-diameter portion 34 of the support 30, the locking surface 76 of the fastener 70, and the outer corner 46a. The vibration-damping member 650 is an annular shape obtained by reversing the orientation of the vibration-damping member 50 in the vibration-damping structure 12 in the axial direction. As shown in Figure 8, the vibration-damping member 650 has an outer circumference 661, an inner circumference 662, a bottom 663, a tip 666, and an inclined portion 668. The outer circumference 661 and the inner circumference 662 correspond to the outer circumference 61 and the inner circumference 662 of the vibration-damping member 50, respectively. The bottom portion 663 connects the +X-side ends of the outer circumference portion 61 and the inner circumference portion 62, respectively. The bottom portion 663 faces the +X side. The bottom portion 63 contacts the locking surface 76 of the fastener 70. The tip portion 666 extends radially inward from the -X end of the outer circumference portion 661. The tip portion 666 faces the -X side. The radial length of the tip portion 666 is shorter than that of the base portion 663. The inclined portion 668 is an inclined surface that connects the tip portion 666 and the inner circumference portion 662. In cross-sectional view, the inclined portion 668 is inclined linearly with respect to the axial direction. The inclined portion 668 faces radially inward and towards the -X side. The inclined portion 668 is in contact with the outer corner portion 46a of the bearing 40. The inclined portion 668 is an example of an opposing surface.

[0033] In the vibration isolation structure 612, the internal clearance of the bearing 40 is reduced by applying an elastic force to the outer ring 44 from the vibration isolation member 650, as in the vibration isolation structure 12. In particular, in the vibration isolation structure 612, the internal clearance of the bearing 40 is reduced when a load directed towards the +X side is applied to the inner ring 41 through the shaft 20 and an elastic force is applied to the outer ring 44. Furthermore, the inclined portion 668 is in contact with the outer ring 44 of the bearing 40. Therefore, the vibration isolation structure 612, like the vibration isolation structure 12, can suppress the transmission of vibrations from the bearing 40, which is positioned between the shaft 20 and the support 30, with a simple configuration, while also suppressing the displacement of the bearing 40's rotation center. Furthermore, with the vibration isolation structure 612, the vibration isolation member 650 can be attached by bringing it into contact with the bearing 40 after the bearing 40 has been fitted into the large-diameter portion 34. In other words, with the vibration isolation structure 612, the vibration isolation member 650 can be attached in a state where its orientation relative to the bearing 40 fitted into the large-diameter portion 34 is adjusted.

[0034] When the vibration-damping member is positioned between the second corner 78 and the outer corner 46a of the bearing 40, the vibration-damping structure according to this disclosure may have a configuration in which the first opposing portion of the support is in contact with the inner end face 42b of the bearing 40, as shown in the vibration-damping structure 712 in Figure 9. Details of the vibration-damping structure 712 will be described below. In the description of the vibration-damping structure 712, when using parts similar to those used in the vibration-damping structure 12 or vibration-damping structure 612 described above, the reference numerals and names of those parts will be used as they are.

[0035] The vibration isolation structure 712 has a support 730 in place of the support 30 in the vibration isolation structure 612. The support 730 has a hole 732 in place of the hole 32 of the support 30. The hole 732 has a small diameter portion 735 and a stepped surface 736 in place of the small diameter portion 35 and stepped surface 36 of the hole 32. The diameter of the small-diameter portion 735 is smaller than the diameter of the small-diameter portion 35 of the hole portion 32. The stepped surface 736 is provided between the large diameter portion 34 and the small diameter portion 735. The stepped surface 736 faces the +X side. When the bearing 40 is positioned in the hole portion 732, the stepped surface 736 faces the outer end face 45b and the inner end face 44b of the outer ring 44. The stepped surface 736 is an example of the first opposing portion. The stepped surface 736 has a projection 737.

[0036] The projection 737 is provided on the radially inner edge of the stepped surface 736 and protrudes toward the bearing 40 relative to the stepped surface 736. The projection 737 faces the +X side. The projection 737 is connected to the small diameter portion 735. The projection 737 contacts the inner end face 42b of the bearing 40. That is, the projection 737 of the stepped surface 736 contacts only the inner end face 42b.

[0037] Furthermore, a lubricating member may be provided between the protrusion 737 and the inner end face 42b of the bearing 40. Also, the protrusion 737 may be a lubricating member provided on the stepped surface 736. The lubricating member may be, for example, a solid lubricant or a solid-like member made of resin, and may be a thrust bearing. The lubricating member may be, for example, a lubricant such as grease or oil. In cases where a protrusion provided on a stepped surface, such as in the vibration-damping structure 712, contacts the inner end face of the bearing, the bearing may be a tapered roller bearing or an angular contact ball bearing.

[0038] As described above, in the vibration isolation structure 712, the protrusion 737 of the stepped surface 736 contacts only the inner end surface 42b. The elastic force applied from the vibration isolation member 650 to the outer ring 44 is transmitted from the outer ring 44 to the protrusion 737 through the rolling elements 40a and the inner ring 41 as an external force directed in the -X direction. When an external force is transmitted from the inner ring 41 of the bearing 40 to the protrusion 737, a reaction force directed in the +X direction is applied from the protrusion 737 to the inner ring 41 in accordance with the external force transmitted to the protrusion 737. At this time, the internal gap of the bearing 40 is further reduced by the elastic force applied from the vibration isolation member 650 to the outer ring 44 and the internal force applied from the protrusion 737 to the inner ring 41. Therefore, the vibration-damping structure 712 can more effectively suppress the displacement of the rotation center of the bearing 40.

[0039] 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.

[0040] In the vibration isolation structure 12 of the embodiment, the inner ring 41 of the bearing 40 is in contact only with the shaft 20 and the rolling elements 40a. However, the inner ring 41 of the bearing 40 may be in contact with a restricting portion 80 provided on the shaft 820, as in the vibration isolation structure 812 shown in Figure 10, thereby restricting its axial position relative to the shaft 820. The vibration isolation structure 812 has a shaft 820 instead of the shaft 20 of the vibration isolation structure 612. Compared to the vibration isolation structure 612, the vibration isolation structure 812 further has a regulating section 80. The vibration isolation structure 812 has a vibration isolation member 650, similar to the vibration isolation structure 612. The shaft 820 has a positioning groove 824 compared to the shaft 20. The positioning groove 824 is annular in shape and opens concavely to the side surface 22 of the shaft 820. The positioning groove 824 is located on the -X side with respect to the bearing 40. In the axial direction, the positioning groove 824 is located on the opposite side of the vibration damping member 650 from the bearing 40. The restricting portion 80 is a retaining ring assembled into the positioning groove 824. The restricting portion 80 is rotatable around the axis XC integrally with the shaft body 820. In the axial direction, the restricting portion 80 is positioned on the opposite side of the vibration-damping member 650 from the bearing 40. The restricting portion 80 is convex with respect to the side surface 22 of the shaft body 820. The restricting portion 80 contacts the inner end face 42b of the bearing 40. The restricting portion 80 does not contact the hole 32 of the support body 30 or the outer ring 44 of the bearing 40. That is, the restricting portion 80 contacts the inner end face 42b of the outer ring 44. The restricting portion 80 restricts the position of the bearing 40 relative to the shaft body 820. The restricting portion 80 restricts the position of the bearing 40 in the vibration-damping structure 812. The vibration-damping structure 812, like the vibration-damping structure 712, can more effectively suppress the displacement of the rotation center of the bearing 40. The restricting portion relating to this disclosure is not limited to the form of a retaining ring. The restricting portion may, for example, be a projection that is integrally formed with the shaft body 20 and is convex relative to the side surface portion 22. When the shaft of the vibration-damping structure according to this disclosure has a restricting portion, the hole in the support does not need to have a small-diameter portion and / or an opposing portion in the direction opposite to the vibration-damping member with respect to the rolling bearing. [Explanation of Symbols]

[0041] 10 Structure 12. Vibration-damping structure 20 Axis Body 22 Side part 30 Support 30a Exterior 32 Hole 34. Large diameter section (an example of a fitting section) 36. Stepped surface (an example of the first opposing part) 38 First corner 40. Bearings (an example of rolling bearings) 40a Rolling element 41 Inner circle 41a Inner diameter part 42 Inner end face 43 First rolling surface 44 Outer ring 44a Outer diameter 45 Outer end face 46 Outer corner 47 Second rolling surface 50 Vibration Isolator 52 Core material 60 Main body 64 Outer periphery 66 End face 68 Opposing surfaces 70 fasteners 76 Locking surface (an example of the second opposing part) 78 Second corner 312 Vibration-damping structure 340 Rolling bearings 346 Outer Corner 347 Chamfered section 412 Vibration-damping structure 440 bearing 450 Vibration Isolator 512 Vibration-damping structure 538 Nusumi Groove 612 Vibration-damping structure 650 Vibration Isolator 712 Vibration-damping structure 736 Step surface 737 Protrusion 812 Vibration-damping structure 80 Regulatory Department

Claims

1. A shaft extending in the axial direction, It is a rolling bearing, An inner ring that fits with the shaft body, having an inner end face facing axially, An outer ring arranged radially outward with respect to the inner ring, The outer end face facing the axial direction, The outer diameter portion facing radially outward, The outer corner portion connecting the outer diameter portion and the outer end face, An outer ring having, A rolling bearing having, A support for the aforementioned rolling bearing, A fitting portion that engages with the outer ring, The inner end face or the opposing portion facing the outer end face, A support having, An annular vibration-damping member is positioned between the fitting portion, the opposing portion, and the outer corner portion, and applies elastic force to the outer ring in the radial and axial directions in conjunction with contact with the outer corner portion. A vibration-damping structure having the following characteristics.

2. The vibration-damping member is, A ring-shaped core material, The main body portion formed around the core material, The vibration isolation structure according to claim 1, having the following characteristics.

3. The vibration-damping structure according to claim 1 or 2, wherein the vibration-damping member has a facing surface that faces the outer corner.

4. The vibration-damping structure according to any one of claims 1 to 3, wherein the outer corner portion is a chamfered portion.

5. The vibration-damping structure according to any one of claims 1 to 4, wherein the vibration-damping member is provided integrally with the outer ring.

6. The vibration damping structure according to any one of claims 1 to 5, wherein a recess groove is formed between the fitting portion and the opposing portion.

7. The opposing portion is, A first opposing portion provided in the first axial direction relative to the rolling bearing, A second opposing portion is provided in a second axial direction opposite to the first axial direction with respect to the rolling bearing, It has, The second opposing portion is a locking surface of a fastener provided on the support, separate from the fitting portion. The vibration-damping structure according to any one of claims 1 to 5, wherein the vibration-damping member is disposed between the fitting portion and the second opposing portion.

8. The vibration isolation structure according to claim 7, wherein the first opposing portion contacts only the inner end face of the inner ring.

9. The vibration isolation structure according to any one of claims 1 to 7, wherein the shaft body further comprises a restricting portion provided in the axial direction on the side of the rolling bearing opposite to the vibration isolation member, which restricts the position of the rolling bearing with respect to the shaft body.

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