JP6699372B2 - Bearing device - Google Patents

Description

  The present disclosure relates to bearing devices, and more particularly to bearing devices for vehicles.

  2. Description of the Related Art Conventionally, in vehicles having a frame-structured vehicle body such as a truck, a bearing device using a tapered roller bearing has been adopted from the viewpoint of load capacity. The bearing device includes an outer ring, an inner ring, and a plurality of rows of tapered rollers. The inner ring is composed of first and second inner ring members whose one end faces in the axial direction are butted against each other. Tapered rollers are arranged between the outer ring and the first inner ring member and between the outer ring and the second inner ring member, respectively.

  An axle tube is inserted into the bearing device. The axle tube is fitted in the axial hole of the inner ring with a clearance. When the differential oil flows out from the axle pipe, the differential oil may travel through the gap between the inner ring and the axle pipe and enter the bearing space from between the first inner ring member and the second inner ring member. Therefore, in the above bearing device, a sealing device called a center seal is attached to the outer peripheral surface of the boundary portion between the first inner ring member and the second inner ring member.

  For example, Patent Document 1 discloses a bearing device in which the structure of the sealing device is devised. In the bearing device of Patent Document 1, an annular recess for mounting the sealing device is formed on the outer peripheral surface of the boundary portion between the first inner ring member and the second inner ring member. The sealing device includes a cored bar having an L-shaped cross section and an elastic portion bonded to the cored bar.

  FIG. 6 of Patent Document 1 discloses, as an embodiment, a sealing device in which an elastic portion is bonded to an inner peripheral surface of a cored bar. A portion of the inner peripheral surface of the core metal to which the elastic portion is not bonded contacts the outer peripheral surface of the first inner ring member. The elastic part has two annular protrusions that project inward in the radial direction. One annular convex portion contacts the outer peripheral surface of the first inner ring member, and the other annular convex portion contacts the second inner ring member.

JP, 2010-25216, A

  When manufacturing a bearing device including an inner ring composed of first and second inner ring members and a sealing device, usually, after fitting the first inner shaft member and the sealing device, the second inner shaft member is attached to the sealing device. Pressed in. At this time, there may arise a problem that the axial center is displaced between the inner ring and the sealing device.

  In the bearing device of Patent Document 1, when the first inner shaft member and the sealing device are fitted to each other, the elastic portion bonded to the core metal contacts the outer peripheral surface of the first inner ring member. Since the elastic portion is made of a rubber material or a resin material, the elastic portion has a large variation in dimension and may not be formed to have an intended thickness. In that case, the core may be pressed radially outward in whole or part by the elastic portion, and the sealing device may be inclined with respect to the first inner ring member. As a result, a deviation occurs between the axis of the first inner ring member and the axis of the sealing device.

  When the axes of the first inner ring member and the sealing device that are fitted to each other do not match, the axes of the second inner ring member that is subsequently press-fitted into the sealing device also do not match. .. If the second inner ring member is press-fitted in such a state that the axial center is displaced between the inner ring and the sealing device, the elastic portion may be sandwiched between the first inner ring member and the second inner ring member. ..

  An object of the present disclosure is to provide a bearing device for a vehicle, which is capable of suppressing a deviation between an axial center of an inner ring and an axial center of a sealing device.

  A bearing device for a vehicle according to the present disclosure includes an inner ring, an outer ring, a plurality of rolling elements, and a sealing device. The inner ring includes first and second inner ring members. The first and second inner ring members are in contact with each other at their one end faces in the axial direction. The inner ring has an annular recess formed on the outer peripheral surface of the boundary portion between the first inner ring member and the second inner ring member. The outer ring is arranged radially outward of the inner ring. The plurality of rolling elements are arranged between the inner ring and the outer ring. The sealing device is attached to the outer peripheral surface of the inner ring to seal the annular recess. The sealing device has a cored bar and an elastic portion. The core metal is fitted to the outer peripheral surface of the first inner ring member. The elastic portion is bonded to the cored bar. The elastic portion is arranged in the annular recess. Both axial end faces of the elastic portion are in contact with both side faces of the annular recess. The entire inner peripheral surface of the elastic portion opposes the bottom surface of the annular recess with a gap.

  According to the bearing device for a vehicle according to the present disclosure, it is possible to suppress deviation between the axis of the inner ring and the axis of the sealing device.

FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a hub unit including a bearing device according to each embodiment. FIG. 2 is a partially enlarged view of a vertical cross section of the bearing device according to the first embodiment, and is a diagram schematically showing the sealing device before being mounted on the inner ring. FIG. 3 is a partially enlarged view of a vertical cross section of the bearing device according to the first embodiment, and is a diagram schematically showing the sealing device after being mounted on the inner ring. FIG. 4 is a partially enlarged view of a vertical cross section of the bearing device according to the second embodiment, and is a diagram schematically showing the sealing device before being mounted on the inner ring. FIG. 5 is a partially enlarged view of a vertical cross section of the bearing device according to the second embodiment, and is a diagram schematically showing the sealing device after being mounted on the inner ring.

  The bearing device for a vehicle according to the embodiment includes an inner ring, an outer ring, a plurality of rolling elements, and a sealing device. The inner ring includes first and second inner ring members. The first and second inner ring members are in contact with each other at their one end faces in the axial direction. The inner ring has an annular recess formed on the outer peripheral surface of the boundary portion between the first inner ring member and the second inner ring member. The outer ring is arranged radially outward of the inner ring. The plurality of rolling elements are arranged between the inner ring and the outer ring. The sealing device is attached to the outer peripheral surface of the inner ring to seal the annular recess. The sealing device has a cored bar and an elastic portion. The core metal is fitted to the outer peripheral surface of the first inner ring member. The elastic portion is bonded to the cored bar. The elastic portion is arranged in the annular recess. Both axial end faces of the elastic portion are in contact with both side faces of the annular recess. The entire inner peripheral surface of the elastic portion opposes the bottom surface of the annular recess with a gap (first configuration).

  According to the first configuration, the core metal of the sealing device is fitted to the outer peripheral surface of the first inner ring member. The cored bar has higher rigidity than the elastic part. Therefore, the tightening margin between the first inner ring member and the sealing device is stably ensured, and the orientation of the sealing device is stable. Therefore, the axial center of the sealing device is less likely to deviate from the axial center of the first inner ring member and the axial center of the second inner ring member that is in contact with the first inner ring member at its one end faces in the axial direction. That is, it is possible to suppress the deviation between the axis of the inner ring and the axis of the sealing device.

  According to the first configuration, the inner peripheral surface of the elastic portion of the sealing device faces the bottom surface of the annular recess of the inner ring with a gap. That is, the inner peripheral surface of the elastic portion does not contact the outer peripheral surface of the inner ring. According to this configuration, the elastic portion does not directly receive a force from the inner ring outward in the radial direction, and therefore the cored bar is not entirely or partially pressed outward in the radial direction by the elastic portion. Therefore, it is possible to stabilize the position of the sealing device with respect to the inner ring, and suppress the deviation between the axis of the inner ring and the axis of the sealing device.

  The inner peripheral surface of the elastic portion may include a tapered surface. The tapered surface has a diameter that increases toward the second inner ring member (second configuration).

  According to the second configuration, the gap between the inner peripheral surface of the elastic portion of the sealing device and the bottom surface of the annular recess is increased on the second inner ring member side by the tapered surface. Therefore, when the second inner ring member is press-fitted into the sealing device fitted to the first inner ring member, it is possible to prevent the elastic portion from being sandwiched between the first inner ring member and the second inner ring member.

  According to the second configuration, when the second inner ring member is press-fitted into the sealing device, the tapered inner surface can guide the second inner ring member to a desired position. For example, when a part of the second inner ring member comes into contact with the tapered surface during press-fitting of the second inner ring member, it is considered that the contact part is displaced radially outward. However, as the press-fitting of the second inner ring member progresses, the contact portion moves inward in the radial direction along the tapered surface. That is, the second inner ring member is naturally arranged at the correct position. Therefore, it is possible to more reliably prevent the axial center of the second inner ring member from deviating from the axial center of the sealing device.

  The core metal may include a tubular portion. The cylindrical portion is fitted to the outer peripheral surface of the first inner ring member outside the annular recess and extends toward the second inner ring member. The elastic portion is bonded to the inner peripheral surface of the tubular portion (third configuration).

  According to the third configuration, the elastic portion in the annular recess is bonded to the inner peripheral surface of the tubular portion of the cored bar. That is, the outer circumference of the elastic portion is surrounded by the tubular portion. Therefore, when the bearing device is used at a high temperature, the cylindrical portion can prevent the elastic portion from expanding radially outward due to thermal expansion. As a result, it is possible to prevent each axial end surface of the elastic portion from separating from each side surface of the annular recess. Therefore, good sealing performance of the sealing device can be maintained.

  The cored bar may include a tubular portion and an annular plate portion having elastic portions bonded to the respective surfaces facing the first and second inner ring members. The tubular portion is fitted to the outer peripheral surface of the first inner ring member inside the annular recess. The annular plate portion is connected to the tubular portion. The annular plate portion extends radially outward of the tubular portion. An elastic portion is adhered to each of the first inner ring member side surface and the second inner ring member side surface of the annular plate portion (fourth configuration).

  According to the fourth configuration, the annular plate portion of the core metal extends in the annular recess in a direction substantially orthogonal to the axial direction of the elastic portion. Therefore, the annular plate portion can reinforce the elastic portion that is compressed in the annular recess in the axial direction. Therefore, for example, it is possible to suppress undesired deformation of the elastic portion due to a compressive force, such as the elastic portion not being able to withstand axial compression and rolling outward in the radial direction. Therefore, good sealing performance of the sealing device can be maintained.

  Hereinafter, embodiments will be described with reference to the drawings. The same or corresponding components in the drawings are designated by the same reference numerals, and the same description will not be repeated. For convenience of description, in each drawing, the configuration may be illustrated in a simplified or schematic manner, or a part of the configuration may be omitted.

<First Embodiment>
[Hub unit configuration]
FIG. 1 is a sectional view of the hub unit 100 taken along a plane passing through the straight line X. The straight line X is the axial center of the hub unit 100. The hub unit 100 is attached to, for example, a vehicle such as a truck. Hereinafter, for convenience of description, with the hub unit 100 attached to the vehicle, the side closer to the vehicle body is referred to as the inner side, and the side farther from the vehicle body is referred to as the outer side. The direction in which the straight line X extends is called the axial direction, and the direction around the straight line X is called the circumferential direction.

  As shown in FIG. 1, the hub unit 100 includes an axle tube 1, a drive shaft 2, a bearing device 3, a hub wheel 4, a hub bolt 5, a brake rotor 7, and a fixing nut 8.

  The axle tube 1 is connected to a differential (not shown). A drive shaft 2 is inserted into the axle tube 1. The drive shaft 2 has a flange 21 at the end on the outer side.

  The hub wheel 4 is arranged radially outward of the axle tube 1. The hub wheel 4 is rotatable with respect to the axle tube 1. The hub wheel 4 is fixed to the flange 21 of the drive shaft 2 by a hub bolt 5. The hub wheel 4 is fixed to the brake rotor 7 by a hub bolt 5. That is, the hub bolt 5 connects the flange 21, the hub wheel 4, and the brake rotor 7.

  The bearing device 3 is arranged between the axle tube 1 and the hub wheel 4. The bearing device 3 fits with the inner peripheral surface of the hub wheel 4. The bearing device 3 fits with the outer peripheral surface of the axle tube 1. The axial movement of the bearing device 3 is restricted by the fixed nut 8.

[Structure of bearing device]
Hereinafter, the configuration of the bearing device 3 according to the first embodiment will be described in detail. As shown in FIG. 1, the bearing device 3 includes an outer ring 31, an inner ring 32, a plurality of rolling elements 33a and 33b, and a sealing device 34.

  The outer ring 31 is made of, for example, a metal such as bearing steel. The outer ring 31 has a first outer ring member 311 and a second outer ring member 312. The first and second outer ring members 311 and 312 each have a substantially cylindrical shape with the straight line X as an axis. The first and second outer ring members 311 and 312 are in contact with each other at their one axial end faces. That is, the inner end surface of the first outer ring member 311 and the outer end surface of the second outer ring member 312 are butted against each other.

  The outer ring 31 has raceway surfaces 313a and 313b on the inner peripheral surface. The orbital surfaces 313a and 313b are substantially annular surfaces having the straight line X as an axis. The raceway surface 313a is formed on the inner peripheral surface of the first outer ring member 311. The raceway surface 313b is formed on the inner peripheral surface of the second outer ring member 312.

  In the present embodiment, the outer ring 31 is composed of the first and second outer ring members 311 and 312, but may be composed of one member. That is, the first and second outer ring members 311 and 312 may be integrally formed.

  Like the outer ring 31, the inner ring 32 is made of metal such as bearing steel. The inner ring 32 is arranged radially inward of the outer ring 31. A bearing space S is formed between the inner ring 32 and the outer ring 31. Both ends of the bearing space S in the axial direction are closed by the sealing devices 35a and 35b.

  The inner ring 32 has a first inner ring member 321 and a second inner ring member 322. The first and second inner ring members 321 and 322 each have a substantially cylindrical shape with the straight line X as an axis. The first and second inner ring members 321 and 322 are in contact with each other at their one end faces in the axial direction. That is, the inner end surface of the first inner ring member 321 and the outer end surface of the second inner ring member 322 are butted against each other.

  The inner ring 32 has raceway surfaces 323a and 323b on the outer peripheral surface. The orbital surfaces 323a and 323b are substantially annular surfaces having the straight line X as an axis. The raceway surfaces 323a and 323b of the inner ring 32 face the raceway surfaces 313a and 313b of the outer ring 31, respectively. The raceway surface 323a is formed on the outer peripheral surface of the first inner ring member 321. The raceway surface 323b is formed on the outer peripheral surface of the second inner ring member 322.

  The rolling elements 33a and 33b are arranged in the bearing space S. The rolling elements 33a are arranged in the circumferential direction on the raceway surface 313a of the outer ring 31 and the raceway surface 323a of the inner ring 32. The rolling elements 33b are arranged in the circumferential direction on the raceway surface 313b of the outer ring 31 and the raceway surface 323b of the inner ring 32. The rolling elements 33a and 33b are held by cages 36a and 36b, respectively.

  The rolling elements 33a and 33b are tapered rollers. The rolling elements 33a and 33b are arranged such that the small end surfaces thereof face each other. That is, each of the rolling elements 33a is arranged such that the small end surface faces the inner side and the large end surface faces the outer side. Each of the rolling elements 33b is arranged such that the small end surface faces the outer side and the large end surface faces the inner side.

  The sealing device 34 is attached to the outer peripheral surface of the inner ring 32. The sealing device 34 has a substantially cylindrical shape with the straight line X as the axis. The sealing device 34 seals the boundary portion between the first inner ring member 321 and the second inner ring member 322 from the outer peripheral side of the inner ring 32.

  2 and 3 are partially enlarged views of the bearing device 3 shown in FIG. 2 and 3, a part of the bearing device 3 in the vicinity of the sealing device 34 is shown. FIG. 2 shows the sealing device 34 before being mounted on the outer peripheral surface of the inner ring 32. FIG. 3 shows the sealing device 34 after being mounted on the outer peripheral surface of the inner ring 32.

  As shown in FIGS. 2 and 3, on the outer peripheral surface of the inner ring 32, an annular recess 323 is formed at the boundary between the first inner ring member 321 and the second inner ring member 322. The annular recess 323 is an annular groove having the straight line X (FIG. 1) as its axis. The annular recess 323 includes a small diameter portion 3211 of the first inner ring member 321 and a small diameter portion 3221 of the second inner ring member 322.

  The small diameter portion 3211 constitutes one end portion (end portion on the inner side) of the first inner ring member 321 in the axial direction. In the first inner ring member 321, the outer diameter of the small diameter portion 3211 is smaller than the outer diameter of the other portions. On the outer peripheral surface of the first inner ring member 321, a step is formed between the small diameter portion 3211 and other portions. The inner diameter of the first inner ring member 321 is substantially constant throughout.

  The small-diameter portion 3221 constitutes one axial end (outer end) of the second inner ring member 322. In the second inner ring member 322, the outer diameter of the small diameter portion 3221 is smaller than the outer diameters of other portions. On the outer peripheral surface of the second inner ring member 322, a step is formed between the small diameter portion 3221 and other portions. The inner diameter of the second inner ring member 322 is substantially constant throughout.

  The small diameter portion 3211 of the first inner ring member 321 is butted against the small diameter portion 3221 of the second inner ring member 322. The outer peripheral surfaces of the small diameter portions 3211 and 3221 form the bottom surface of the annular recess 323. In the present embodiment, the diameter of the bottom surface of the annular recess 323 is substantially constant.

  On the outer peripheral surface of the first inner ring member 321, the outer side surface of the annular recess 323 is formed by a step (a top surface) between the small diameter portion 3211 and other portions. On the outer peripheral surface of the second inner ring member 322, the inner side surface of the annular recess 323 is formed by a step (a top surface) between the small diameter portion 3221 and other portions.

  The annular recess 323 of the inner ring 32 is sealed by the sealing device 34. The sealing device 34 includes a core metal 341 and an elastic portion 342.

  The core metal 341 is made of metal such as SPCC, for example. The core metal 341 is arranged coaxially with the inner ring 32. The core metal 341 includes a tubular portion 3411 and an annular plate portion 3412.

  The tubular portion 3411 has a cylindrical shape with the straight line X (FIG. 1) as its axis. The tubular portion 3411 is attached to the outer peripheral surface of the first inner ring member 321. The inner peripheral surface of the tubular portion 3411 contacts the outer peripheral surface of the first inner ring member 321. The tubular portion 3411 is fitted to the outer peripheral surface of the first inner ring member 321.

  The outer side portion of the inner peripheral surface of the tubular portion 3411 directly contacts the outer peripheral surface of the first inner ring member 321. The tubular portion 3411 is fitted to the outer peripheral surface of the first inner ring member 321 outside the annular recess 323. The tubular portion 3411 does not contact the second inner ring member 322.

  The tubular portion 3411 extends toward the second inner ring member 322. A portion of the inner peripheral surface of the tubular portion 3411 that is not fitted to the outer peripheral surface of the first inner ring member 321 is arranged radially outward of the annular recess 323. That is, a part of the tubular portion 3411 covers at least a part of the annular recess 323. The tubular portion 3411 preferably covers the entire small diameter portion 3211 of the first inner ring member 321 and overlaps with the small diameter portion 3221 of the second inner ring member 322 when viewed from the outer peripheral side.

  An annular plate portion 3412 is connected to the inner end of the tubular portion 3411. The annular plate portion 3412 is formed integrally with the tubular portion 3411. The annular plate portion 3412 extends outward in the radial direction of the tubular portion 3411. The annular plate portion 3412 has an annular shape with the straight line X (FIG. 1) as its axis.

  The elastic portion 342 is bonded to the core metal 341. The elastic portion 342 is made of, for example, a rubber material such as fluororubber or nitrile rubber or a resin material. The elastic portion 342 can be formed on the core metal 341 by vulcanization molding or the like.

  The elastic portion 342 is bonded to the inner peripheral surface of the tubular portion 3411. The elastic portion 342 is formed on a portion of the inner peripheral surface of the tubular portion 3411 that is not fitted to the outer peripheral surface of the first inner ring member 321. The elastic portion 342 has a substantially cylindrical shape with the straight line X (FIG. 1) as the axis. That is, the elastic portion 342 is arranged coaxially with the inner ring 32.

  The elastic portion 342 is arranged in the annular recess 323. As shown in FIG. 3, when the sealing device 34 is mounted on the outer peripheral surface of the inner ring 32, both axial end surfaces of the elastic portion 342 contact both side surfaces of the annular recess 323. The outer end surface of the elastic portion 342 contacts the outer side surface of the annular recess 323. The inner end surface of the elastic portion 342 contacts the inner side surface of the annular recess 323. The elastic portion 342 is axially compressed by the side surfaces of the annular recess 323.

  The minimum inner diameter of the elastic portion 342 is larger than the diameter of the bottom surface of the annular recess 323. The entire inner peripheral surface of the elastic portion 342 faces the bottom surface of the annular recess 323 with a gap C therebetween. That is, the inner peripheral surface of the elastic portion 342 is not in contact with the outer peripheral surfaces of the first and second inner ring members 321 and 322. The inner peripheral surface of the elastic portion 342 contacts the outer peripheral surface of the inner ring 32 in a state where the elastic portion 342 is axially compressed by both side surfaces of the annular recess 323, that is, in a state where the inner ring 32 and the sealing device 34 are fitted to each other. do not do.

  The size of the gap C can be set to 0.3 to 0.5 mm, for example. The size of the gap C here is the minimum value of the radial distance from the bottom surface of the annular recess 323 to the inner peripheral surface of the elastic portion 342.

  The inner peripheral surface of the elastic portion 342 includes a tapered surface 3421. The tapered surface 3421 is a surface that increases in diameter toward the second inner ring member 322.

  In the present embodiment, the inner peripheral surface of the elastic portion 342 starts to expand from the outer side with respect to the abutting end surfaces of the first and second inner ring members 321 and 322. That is, the starting point of the tapered surface 3421 is located closer to the first inner ring member 321 than the abutting end surface. However, the starting point of the tapered surface 3421 may be located closer to the second inner ring member 322 than the abutting end surface.

  In the present embodiment, the inner peripheral surface of the elastic portion 342 is expanded until reaching the inner side surface of the annular recess 323. However, the diameter expansion of the inner peripheral surface of the elastic portion 342 may be completed before reaching the inner side surface of the annular recess 323.

  The length and taper rate of the tapered surface 3421 in the axial direction are not particularly limited and can be appropriately determined. The taper rate of the tapered surface 3421 can be set to, for example, 0.25 to 0.50.

[Assembling method of inner ring and sealing device]
Hereinafter, a method of assembling the inner ring 32 and the sealing device 34 will be briefly described.

  First, the annular plate portion 3412 of the core metal 341 is pressed to press-fit the sealing device 34 into the first inner ring member 321. As a result, the tubular portion 3411 of the core metal 341 and the first inner ring member 321 are fitted together.

  Next, the second inner ring member 322 is press-fitted into the sealing device 34 assembled to the first inner ring member 321. At this time, the second inner ring member 322 is moved in the axial direction until the outer end surface of the second inner ring member 322 abuts the inner end surface of the first inner ring member 321.

  When the first and second inner ring members 321, 322 and the sealing device 34 are assembled, the elastic portions 342 come into contact with both side surfaces of the annular recess 323 and are compressed in the axial direction. This seals the annular recess 323.

[effect]
In the bearing device 3 according to the present embodiment, the inner peripheral surface of the core metal 341 of the sealing device 34 and the outer peripheral surface of the first inner ring member 321 are fitted together. The core metal 341 is made of metal and has higher rigidity than the elastic portion 342. Therefore, the tightening margin between the first inner ring member 321 and the sealing device 34 can be stably ensured. Therefore, the sealing device 34 can be stably arranged in a predetermined direction. As a result, it is possible to suppress the deviation of the axial center between the axial center of the sealing device 34 and the inner ring 32.

  In this embodiment, the inner peripheral surface of the elastic portion 342 is not in contact with the outer peripheral surface of the inner ring 32. Therefore, the elastic portion 342 does not directly receive the outward force in the radial direction from the inner ring 32. Therefore, even if the elastic portion 342 varies in size, the elastic portion 342 does not spread the metal core 341 in whole or in part, and the inclination of the sealing device 34 is suppressed. Therefore, it is possible to suppress the deviation between the axis of the sealing device 34 and the axis of the inner ring 32.

  By preventing the inner peripheral surface of the elastic portion 342 from contacting the outer peripheral surface of the inner ring 32, it is possible to prevent the elastic portion 342 from coming off from the core metal 341 when the inner ring 32 and the sealing device 34 are assembled. That is, when the sealing device 34 is press-fitted into the first inner ring member 321, the inner peripheral surface of the elastic portion 342 and the outer peripheral surface of the first inner ring member 321 do not slide relative to each other, so that the elastic portion 342 does not move in the axial direction. Friction does not work. Similarly, when the second inner ring member 322 is press-fitted into the sealing device 34, the outer peripheral surface of the second inner ring member 322 and the inner peripheral surface of the elastic portion 342 do not slide relative to each other. Friction does not work. Therefore, it is possible to prevent the elastic portion 342 from peeling from the core metal 341 due to friction.

  As described above, according to the present embodiment, it is possible to suppress the deviation of the axial center between the sealing device 34 and the first inner ring member 321. That is, it is possible to prevent a part of the elastic portion 342 from being displaced radially inward from a predetermined position due to the inclination of the sealing device 34. Therefore, when the second inner ring member 322 is press-fitted into the sealing device 34 assembled to the first inner ring member 321, the elastic portion 342 is prevented from being sandwiched between the first inner ring member 321 and the second inner ring member 322. be able to.

  In the present embodiment, the inner peripheral surface of the elastic portion 342 includes a tapered surface 3421 whose diameter increases toward the second inner ring member 322. That is, on the second inner ring member 322 side, the gap between the inner peripheral surface of the elastic portion 342 and the bottom surface of the annular recess 323 is large. Therefore, when the second inner ring member 322 is press-fitted into the sealing device 34, it is possible to more reliably prevent the elastic portion 342 from being sandwiched between the first inner ring member 321 and the second inner ring member 322.

  When part of the second inner ring member 322 comes into contact with the tapered surface 3421 during press-fitting of the second inner ring member 322, the second inner ring member 322 is guided by the tapered surface 3421. That is, the portion of the second inner ring member 322 that is in contact with the tapered surface 3421 moves radially inward along the tapered surface 3421 as the press-fitting of the second inner ring member 322 progresses. As a result, the second inner ring member 322 is naturally arranged at the correct position. Therefore, it is possible to more reliably prevent the axis of the second inner ring member 322 from deviating from the axis of the sealing device 34.

  In the present embodiment, the elastic portion 342 is formed on the inner peripheral surface of the cylindrical portion 3411 of the cored bar 341. Therefore, the elastic portion 342 can be suppressed from the outer peripheral side by the tubular portion 3411. Therefore, when the bearing device 3 is used at a high temperature, it is possible to suppress the elastic portion 342 from expanding radially outward due to thermal expansion. As a result, it is possible to prevent each axial end surface of the elastic portion 342 from separating from each side surface of the annular recess 323. Therefore, the good sealing performance of the sealing device 34 can be maintained.

<Second Embodiment>
Hereinafter, the bearing device 3A according to the second embodiment will be described with reference to FIGS. 4 and 5. 4 and 5 are enlarged views showing a portion of the bearing device 3A in the vicinity of the sealing device 37. FIG. 4 shows the sealing device 37 before being attached to the outer peripheral surface of the inner ring 32. FIG. 5 shows the sealing device 37 after being mounted on the outer peripheral surface of the inner ring 32.

  The configuration of the hub unit to which the bearing device 3A is attached is the same as the configuration of the hub unit 100 described in the first embodiment. The bearing device 3A differs from the bearing device 3 according to the first embodiment only in the configuration of the sealing device 37. Therefore, in the present embodiment, only the configuration of the sealing device 37 will be described.

  As shown in FIGS. 4 and 5, the sealing device 37 seals the annular recess 323 of the inner ring 32. The sealing device 37 has a core metal 371 and elastic portions 372a and 372b. The materials of the core metal 371 and the elastic portions 372a and 372b are the same as the materials of the core metal 341 and the elastic portion 342 of the sealing device 34 of the first embodiment, respectively.

  The core metal 371 is arranged coaxially with the inner ring 32. The core metal 371 includes a tubular portion 3711 and an annular plate portion 3712.

  The tubular portion 3711 has a cylindrical shape with the straight line X (FIG. 1) as its axis. The tubular portion 3711 is attached to the outer peripheral surface of the first inner ring member 321. The inner peripheral surface of the tubular portion 3711 contacts the outer peripheral surface of the first inner ring member 321. The tubular portion 3711 is fitted to the outer peripheral surface of the first inner ring member 321.

  The tubular portion 3711 contacts the first inner ring member 321 inside the annular recess 323. The entire inner peripheral surface of the tubular portion 3711 is in direct contact with the outer peripheral surface of the first inner ring member 321. The inner peripheral surface of the tubular portion 3711 is in contact with the outer peripheral surface of the small diameter portion 3211 of the first inner ring member 321.

  An annular plate portion 3712 is connected to the inner end of the tubular portion 3711. The annular plate portion 3712 is formed integrally with the tubular portion 3711. The annular plate portion 3712 has an annular shape with the straight line X (FIG. 1) as its axis.

  The annular plate portion 3712 extends outward in the radial direction of the tubular portion 3711. The annular plate portion 3712 projects radially outward from the annular recess 323. The outer diameter of the annular plate portion 3712 is larger than the outer diameter of portions of the first and second inner ring members 321 and 322 other than the small diameter portions 3211 and 3221.

  The elastic portions 372a and 372b are bonded to the core metal 371. The elastic portion 372a is bonded to the outer peripheral surface of the tubular portion 3711 and the surface of the annular plate portion 372 on the first inner ring member 321 side (outer side). The elastic portion 372b is adhered to the surface of the annular plate portion 372 on the second inner ring member 322 side (inner side).

  The elastic portions 372a and 372b each have a substantially cylindrical shape with the straight line X (FIG. 1) as an axis. That is, the elastic portions 372a and 372b are arranged coaxially with the inner ring 32.

  The elastic portions 372a and 372b are arranged in the annular recess 323. As shown in FIG. 5, when the sealing device 37 is mounted on the outer peripheral surface of the inner ring 32, the outer end surface of the elastic portion 372a contacts the outer side surface of the annular recess 323. When the sealing device 37 is mounted on the outer peripheral surface of the inner ring 32, the inner end surface of the elastic portion 372b contacts the inner side surface of the annular recess 323. The elastic portion 372a is axially compressed between the outer side surface of the annular recess 323 and the annular plate portion 372. The elastic portion 372ab is axially compressed between the inner side surface of the annular recess 323 and the annular plate portion 372.

  The tubular portion 371 is arranged between the inner peripheral surface of the elastic portion 372a and the outer peripheral surface of the first inner ring member 321. Therefore, the inner peripheral surface of the elastic portion 372a does not contact the outer peripheral surface of the first inner ring member 321.

  The elastic portion 372b includes a tapered surface 3721. The tapered surface 3721 is a surface that increases in diameter toward the second inner ring member 322. The inner peripheral surface of the elastic portion 372b is not in contact with the bottom surface of the annular recess 323. That is, the entire inner peripheral surface of the elastic portion 372b faces the bottom surface of the annular recess 323 with a gap.

  In this embodiment, substantially the entire inner peripheral surface of the elastic portion 372b is the tapered surface 3721. However, only a part of the inner peripheral surface of the elastic portion 372b may be the tapered surface 3721. The length of the tapered surface 3721 and the taper ratio of the tapered surface 3721 in the axial direction are not particularly limited and can be appropriately determined. The taper rate of the tapered surface 3721 can be set to, for example, 0.25 to 0.50.

  In the present embodiment, elastic portions 372a and 372b are formed on the annular plate portion 3712 that is substantially orthogonal to the axial direction. Therefore, the elastic portions 372a and 372b that are compressed in the axial direction can be reinforced by the annular plate portion 3712. Therefore, for example, it is possible to suppress undesired deformation of the elastic portions 372a, 372b, such as the elastic portions 372a, 372b rolling up without being able to withstand the axial compression. Therefore, the sealing performance of the sealing device 37 can be favorably maintained.

  Although the embodiments have been described above, the present disclosure is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present disclosure.

  In each of the above-described embodiments, the core metal of the sealing device is composed of the tubular portion and the annular plate portion, but is not limited to this configuration. For example, the cored bar may not have the annular plate portion.

  In each of the above embodiments, the elastic portion of the sealing device has a tapered surface on the inner peripheral surface thereof. However, it is not particularly limited to this. The inner peripheral surface of the elastic portion may have a diameter that gradually increases toward the second inner ring member, or may have a substantially constant diameter.

3, 3A: Bearing device 31: Outer ring 32: Inner ring 321: First inner ring member 322: Second inner ring member 323: Annular recesses 33a, 33b: Rolling elements 34, 37: Sealing devices 341, 371: Cores 3411, 3711: Cylindrical parts 3412, 3712: Annular plate parts 342, 372a, 372b: Elastic parts 3421, 3721: Tapered surfaces

Claims (4)

A bearing device for a vehicle,
An inner ring including first and second inner ring members whose axial one end surfaces are in contact with each other, wherein an annular recess is formed on an outer peripheral surface of a boundary portion between the first inner ring member and the second inner ring member;
An outer ring arranged radially outward of the inner ring,
A plurality of rolling elements arranged between the inner ring and the outer ring,
A sealing device mounted on the outer peripheral surface of the inner ring to seal the annular recess,
Equipped with
The sealing device is
A cored bar fitted to the outer peripheral surface of the first inner ring member,
An elastic portion adhered to the core metal and arranged in the annular recess,
Have
Both end surfaces in the axial direction of the elastic portion are in contact with both side surfaces of the annular recess,
The bearing device, wherein the inner peripheral surface of the elastic portion is opposed to the bottom surface of the annular recess with a gap therebetween over the entire surface. The bearing device according to claim 1,
The inner peripheral surface of the elastic portion is
A tapered surface that expands in diameter toward the second inner ring member,
Bearing device. The bearing device according to claim 1 or 2, wherein
The core metal is
A tubular portion that is fitted to the outer peripheral surface of the first inner ring member outside the annular recess and extends toward the second inner ring member, and has the elastic portion bonded to the inner peripheral surface.
Bearing device. The bearing device according to claim 1 or 2, wherein
The core metal is
A tubular portion fitted to the outer peripheral surface of the first inner ring member inside the annular recess;
An annular plate portion that is connected to the tubular portion, extends radially outward of the tubular portion, and has the elastic portion bonded to each of the first inner ring member side surface and the second inner ring member side surface. When,
Bearing device.

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