Hub unit bearing

Abstract

To realize a structure capable of preventing relative displacement of a slinger to a hub, while preventing galling and undesired deformation from occurring in the slinger, when the slinger is externally fitted to the hub.SOLUTION: An inner peripheral surface of a first seal member 30 coupled and fixed to a cylindrical part 32 of a slinger body 29 is externally fitted to a cylindrical surface part 15, and an axial outside surface of a second seal member 31 coupled and fixed to an axial outside surface (of an outer diameter side flat plate part 36) of an upright plate part 33 abuts against an axial inside surface (flat surface part 14) of a rotary flange 10.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a hub unit bearing for rotatably supporting a wheel and a braking rotor of an automobile relative to a suspension system. [Background technology]

[0002] The wheels and braking rotors of an automobile are rotatably supported by a suspension system through a hub unit bearing. The hub unit bearing includes an outer ring having a double row outer ring raceway on its inner circumferential surface, a hub having a double row inner ring raceway on its outer circumferential surface and a rotating flange protruding radially outward from a portion located axially outward from the outer ring, and a plurality of rolling elements arranged to roll between the double row outer ring raceway and the double row inner ring raceway.

[0003] In addition, "outside" in the axial direction refers to the outside of the vehicle body when the hub unit bearing is assembled to the automobile, and conversely, the center of the vehicle body when the hub unit bearing is assembled to the automobile is referred to as "inside" in the axial direction.

[0004] The hub unit bearing further includes a seal device that closes an axially outer opening of a rolling element installation space that exists between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub. Japanese Patent Application Laid-Open No. 2010-261598 (Patent Document 1) describes a seal device that includes a core metal that is fitted and fixed to the axially outer end of the outer ring, and a seal material that has a plurality of seal lips whose tip ends are in sliding contact with the outer peripheral surface of the axially middle part of the hub or the axially inner surface of the rotating flange, and is bonded and fixed to the core metal.

[0005] Here, as described in JP 2017-180599 A (Patent Document 2), the part of the outer peripheral surface of the hub where the tip of the seal lip slides is subjected to finishing using a grinding wheel (rotary grinding wheel). When finishing the outer peripheral surface of the hub using a grinding wheel, the hub is supported by a magnet chuck with their central axes eccentric to each other in order to ensure the pressing force of the grinding wheel against the outer peripheral surface of the hub. Therefore, the shoe supporting the part of the outer peripheral surface of the hub that is approximately opposite in the radial direction to the part where the grinding wheel is pressed is likely to wear out, and the center height of the hub and the center height of the grinding wheel are likely to become inconsistent during finishing. For this reason, the position of the grinding surface of the grinding wheel relative to the axial inner surface of the rotating flange changes in the radial direction of the hub, and logarithmic spiral (spiral) grinding streaks may be formed on the axial inner surface of the rotating flange.

[0006] When logarithmic spiral grinding marks are formed on the axial inner surface of the rotating flange, the tip of the seal lip of the seal ring will penetrate deep into the recess of the grinding marks, and when the hub rotates, it will be forced to move back and forth in the radial direction, causing vibration, which may result in an abnormal noise known as seal squeal.

[0007] In contrast, JP 2017-137973 A (Patent Document 3) describes a sealing device in which a slinger having an L-shaped cross-sectional shape is fitted onto the outer peripheral surface of the axial middle part of the hub, and the tip of a seal lip provided on the seal body is brought into sliding contact with the slinger. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2010-261598 A [Patent Document 2] JP 2017-180599 A [Patent Document 3] JP 2017-137973 A [Patent Document 4] JP 2017-129197 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, a moment load due to road reaction force is applied to the hub unit bearing mainly when the vehicle is turning. Stress due to such moment load tends to concentrate on the radially inner portion of the axially inner surface of the rotating flange. For this reason, the radially inner portion of the axially inner surface of the rotating flange is usually configured as a concave curved surface with a large radius of curvature.

[0010] Additionally, in order to maintain a constant camber angle of the wheels and ensure the vehicle's handling stability regardless of the moment load based on road reaction force, hub unit bearings are required to have a large moment rigidity. For this reason, hub unit bearings are given a back-to-back (DB) type contact angle to the rolling elements. Furthermore, from the standpoint of improving moment rigidity, it is preferable to make the inter-row distance between rolling elements arranged in double rows as large as possible.

[0011] As described above, if the radially inner portion of the axially inner surface of the rotating flange is formed with a concave curved surface with a large radius of curvature, or if the distance between the rows of rolling elements is increased, it becomes difficult to ensure the axial length of the cylindrical surface portion that exists between the rotating flange and the axially outer inner ring raceway on the outer periphery of the hub. If the axial length of this cylindrical surface portion cannot be sufficiently ensured and the fitting length of the slinger relative to the hub cannot be sufficiently ensured, the slinger will easily rotate (creep) relative to the hub or be displaced relative to the axial direction.

[0012] In particular, when the axially outer surface of the slinger is in contact with the axially inner surface of the rotating flange, if the rotating flange is deformed to tip (tilt) in the axial direction due to a moment load, the slinger is pushed in the axial direction by the rotating flange, which also makes it easier for the slinger to be displaced in the axial direction relative to the hub.

[0013] Japanese Patent Application Laid-Open No. 2017-129197 (Patent Document 4) describes a seal device in which a fitting tubular portion of a slinger that is fitted and fixed to the outer peripheral surface of a hub is folded back into a U-shape. This seal device can increase the fitting force of the slinger relative to the hub, and can prevent creep and relative axial displacement of the slinger relative to the hub.

[0014] However, the slinger is usually made of stainless steel plate, which is difficult to process plastically (easily prone to processing embrittlement). For this reason, it is difficult to fold the fitting tubular part of the slinger into a U-shape. Even if it is possible to fold it back, if the rigidity of the fitting tubular part in the radial direction becomes excessively large, the contact surface pressure between the outer circumferential surface of the hub and the inner circumferential surface of the fitting tubular part increases, which may cause galling on the inner circumferential surface of the fitting tubular part or undesirable deformation of the upright part bent from the axially outer end of the fitting tubular part toward the radially outer side. In addition, since large residual stress occurs in the slinger due to processing hardening, there is a possibility that cracks may occur after the slinger is attached to the hub, i.e., so-called placement cracks may occur.

[0015] SUMMARY OF THE PRESENT DISCLOSURE In view of the above-mentioned circumstances, an object of the present invention is to provide a hub unit bearing structure that can prevent the sliding surface of the seal lip from being displaced relative to the hub. [Means for solving the problem]

[0016] The hub unit bearing of the present invention comprises an outer ring, a hub, a plurality of rolling elements, and a seal device. The outer ring has a double row outer ring raceway on its inner circumferential surface. The hub has a rotating flange provided at a portion located axially outer than the outer ring and protruding radially outward, a double-row inner ring raceway provided on its outer peripheral surface, and an engaging recess provided on the outer peripheral surface between the rotating flange and the axially outer inner ring raceway of the double-row inner ring raceway in the axial direction. The plurality of rolling elements are disposed so as to roll freely between the double row outer ring raceways and the double row inner ring raceways. The seal device has a slinger and a seal ring, and closes an axially outer opening of a rolling element installation space that exists between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub. The slinger has a slinger body, a first seal, and a second seal. The slinger body includes: Made of metal plate, the entire inner circumference is The hub Outer surface of Among these, a circumference between the rotating flange and the axially outer inner ring raceway in the axial direction is Radially spaced Placed Ta A cylindrical portion and a bent portion extending from an axially outer end of the cylindrical portion toward a radially outer side. and the entire axially outer surface of the rotary flange is disposed axially apart from the axially inner surface of the rotary flange. It has a vertical plate portion. the first seal member has a first engaging protrusion that engages with the engaging recess, and is joined and fixed to the cylindrical portion so as to cover at least a portion of an inner peripheral surface of the cylindrical portion in the axial direction; and the The inner peripheral surface is fitted onto a portion of the outer peripheral surface of the hub between the rotating flange and the axially outer inner ring raceway. The second seal member is bonded and fixed to an axially outer surface of the upright portion, and the The axially outer surface is in contact with the axially inner surface of the rotating flange. The seal ring has at least one seal lip, the tip of which is in sliding contact with or closely opposed to the axially inner surface of the upright portion.

[0017] For example, the first engaging protrusion can be engaged with the engaging recess by a so-called snap fastening.

[0018] Each of the first seal material and the second seal material has flexibility, such as an elastomer like rubber. Elastic material Consists of Will be .

[0019] The hub may have a flange side engagement recess on the axially inner surface of the rotating flange, the flange side engagement recess being recessed axially outward, and the second sealing material may have a second engagement protrusion that engages with the flange side engagement recess. Effect of the Invention

[0020] According to the hub unit bearing of the present invention, when the slinger is fitted onto the hub, it is possible to prevent the occurrence of galling or undesirable deformation of the slinger, or the occurrence of so-called placement cracks, while also preventing the sliding surface of the seal lip from displacing relative to the hub. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a cross-sectional view showing a hub unit bearing according to a first example of the embodiment. [Diagram 2] FIG. 2 is an enlarged view of the portion X in FIG. [Diagram 3] FIG. 3 is a view corresponding to FIG. 2, showing a hub unit bearing according to a second example of the embodiment. [Figure 4] FIG. 4 is a view corresponding to FIG. 2, showing a hub unit bearing according to a third example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] [First Example of Implementation] 1 and 2 show a first embodiment of the present invention. The hub unit bearing 1 of this embodiment is for a driving wheel, and includes an outer ring 2, a hub 3, a plurality of rolling elements 4a, 4b, and It is equipped with a pair of sealing devices 5a, 5b.

[0023] The outer ring 2 is made of hard metal such as medium carbon steel. The outer ring 2 has double-row outer ring raceways 6a, 6b on its inner circumferential surface, and has a stationary flange 7 protruding radially outward at an axially intermediate portion. The stationary flange 7 has support holes 8 penetrating in the axial direction at multiple circumferential positions at the radially intermediate portion.

[0024] In this example, the support hole 8 is configured as a screw hole. The outer ring 2 is supported and fixed to the suspension by a support bolt that is inserted through a through hole provided in the knuckle of the suspension and is screwed into the support hole 8 of the stationary flange 7 from the inside in the axial direction, so that the outer ring 2 does not rotate even when the wheel rotates.

[0025] The hub 3 is disposed coaxially with the outer ring 2 and radially inward of the outer ring 2. The hub 3 has double row inner ring raceways 9a, 9b on its outer peripheral surface facing the double row outer ring raceways 6a, 6b, and has a rotating flange 10 that protrudes radially outward at a portion located axially outward of the axially outer end of the outer ring 2. Furthermore, the hub 3 has a cylindrical pilot portion 11 at its axially outer end.

[0026] The rotating flange 10 has mounting holes 12 penetrating in the axial direction at multiple circumferential positions in a radially intermediate portion. Studs 13 for connecting and fixing a braking rotor such as a disk or drum and a wheel constituting a wheel to the rotating flange 10 are press-fitted (serration fitted) into each mounting hole 12. That is, in this example, the mounting holes 12 are configured as press-fit holes.

[0027] The braking rotor and wheel are fixed to the rotating flange 10 by inserting the pilot portion 11 into a central hole provided in the center of each of them, inserting the studs 13 into through holes provided at multiple locations in the circumferential direction of each of them in the radial middle portion, and screwing a hub nut onto the tip of the stud 13.

[0028] The mounting holes of the rotating flange may be threaded holes. In this case, the braking rotor and the wheel are fixed to the rotating flange by threading a hub bolt that passes through a through hole in the braking rotor and a through hole in the wheel into the mounting hole.

[0029] In this example, the rotating flange 10 has a flat surface portion 14 on the radially inner side of its axially inner surface, which has a hollow circular end surface shape when viewed from the axially inner side, and is perpendicular to the central axis of the hub 3. The hub 3 also has a cylindrical surface portion 15, the outer diameter of which does not change in the axial direction, on the outer peripheral surface between the rotating flange 10 and the axially outer inner ring raceway 9a of the double row inner ring raceways 9a, 9b. In other words, the hub 3 has a cylindrical surface portion 15 on the outer peripheral surface of an axially outer inner ring shoulder portion 16 adjacent to the axially outer side of the axially outer inner ring raceway 9a. The cylindrical surface portion 15 also has an engagement recess 17 having a triangular cross-sectional shape around the entire circumference on the axially inner side. The hub 3 also has a corner R portion 18 on the outer peripheral surface of the axially middle portion, which connects the flat surface portion 14 and the cylindrical surface portion 15 and has a circular arc cross-sectional shape.

[0030] Since the hub unit bearing 1 of this example is a hub unit bearing for a driving wheel, the hub 3 has a spline hole 19 penetrating in the axial direction at the center. The tip of a drive shaft that is rotationally driven by an engine or electric motor as a drive source is splined into the spline hole 19. When the vehicle is traveling, the hub 3 is rotationally driven by the drive shaft, which in turn rotationally drives the wheels and braking rotors that are coupled and fixed to the rotating flange 10 of the hub 3.

[0031] However, the hub unit bearing of the present invention can also be applied to a hub unit bearing for a driven wheel. In this case, the spline holes can be omitted and the hub can be constructed as a solid body.

[0032] The hub 3 of this example is formed by combining an inner ring 20 and a hub ring 21 .

[0033] The inner ring 20 is made of a hard metal such as bearing steel, etc. The inner ring 20 has, on its outer circumferential surface, an inner ring raceway 9b on the axially inner side of the double row inner ring raceways 9a, 9b.

[0034] The hub ring 21 is made of hard metal such as medium carbon steel. The hub ring 21 has an axially outer inner ring raceway 9a of the double row inner ring raceways 9a, 9b at the axially middle portion of the outer peripheral surface. The hub ring 21 has a rotation flange 10 that protrudes radially outward at a portion located axially outer than the axially outer inner ring raceway 9a, and has a cylindrical pilot portion 11 at the axially outer end.

[0035] The hub ring 21 also has a small diameter section 22, located axially inward of the inner ring raceway 9a on the axially outer side, which has an outer diameter smaller than that of a section adjacent to the axially outer side and onto which the inner ring 20 is fitted. The hub ring 21 further has a crimping section 23 that bends radially outward from the axially inner end of the small diameter section 22 and presses against the axially inner end face of the inner ring 20. That is, the hub 3 of this example is constructed by clamping the inner ring 20 from both axial sides between the crimping section 23 and a step surface 24 that bends from the axially outer end of the outer circumferential surface of the small diameter section 22 with the inner ring 20 fitted onto the small diameter section 22 of the hub ring 21.

[0036] The rolling elements 4a, 4b are each arranged between the double row outer ring raceways 6a, 6b and the double row inner ring raceways 9a, 9b in a state of being held by the cages 25a, 25b so as to be freely rollable. As a result, the hub 3 is supported rotatably on the radially inner side of the outer ring 2. In this example, balls are used as the rolling elements 4a, 4b, but tapered rollers can be used instead of balls. The hub unit bearing 1 of this example has an equal diameter PCD type structure in which the pitch circle diameter of the rolling elements 4a in the axially outer row and the pitch circle diameter of the rolling elements 4b in the axially inner row are equal to each other. However, the present invention can also be applied to a different diameter PCD type hub unit bearing in which the pitch circle diameter of the rolling elements in the axially outer row is larger or smaller than the pitch circle diameter of the rolling elements in the axially inner row.

[0037] The pair of sealing devices 5a, 5b close the openings on both axial sides of the rolling element installation space 26 that exist between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3. This prevents foreign matter such as muddy water from entering the rolling element installation space 26 from the external space and prevents grease sealed in the rolling element installation space 26 from leaking into the external space.

[0038] Of the pair of seal devices 5a, 5b, the seal device 5a that closes the axially outer opening of the rolling element installation space 26 includes a slinger 27 and a seal ring .

[0039] The slinger 27 comprises a slinger body 29 , a first seal material 30 , and a second seal material 31 .

[0040] The slinger body 29 is formed by bending a rust-resistant metal plate such as a stainless steel plate, and has a tubular portion 32 that is arranged around the cylindrical surface portion 15 of the hub 3 (fitted via a first sealing material 30), and a standing portion 33 that is bent radially outward from the axially outer end of the tubular portion 32.

[0041] The standing plate portion 33 includes, in order from the radial inside, an inner diameter side flat plate portion 34, an inclined plate portion 35, an outer diameter side flat plate portion 36, and an overhanging portion 37.

[0042] The inner diameter side flat plate portion 34 is bent at a right angle from the axially outer end portion of the cylindrical portion 32 toward the radially outer side, and has a hollow circular end face shape when viewed from the axial direction. Therefore, both axial side surfaces of the inner diameter side flat plate portion 34 are formed by flat surfaces perpendicular to the central axis of the slinger 27.

[0043] The inclined plate portion 35 is formed in the axial direction from the radially outer end of the inner diameter side flat plate portion 34. outside In other words, the inclined plate portion 35 is configured in a truncated cone shape.

[0044] The outer diameter side flat plate portion 36 is bent in a radially outward direction from the end portion on the radially outer side and the axially outer side of the inclined plate portion 35, and has a hollow circular end face shape when viewed from the axial direction. Both axial side surfaces of the outer diameter side flat plate portion 36 are formed by flat surfaces perpendicular to the central axis of the slinger 27. In other words, the outer diameter side flat plate portion 36 is disposed parallel to the inner diameter side flat plate portion 34.

[0045] The eaves portion 37 is bent at a right angle from the radially outer end of the outer diameter side flat plate portion 36 toward the axially inner side. Therefore, the outer peripheral surface and inner peripheral surface of the eaves portion 37 are formed by a cylindrical surface centered on the central axis of the slinger 27. The inner peripheral surface of the tip end (axially inner end) of the eaves portion 37 faces the outer peripheral surface of the axially outer end of the outer ring 2.

[0046] The first seal material 30 is made of a flexible elastomer such as rubber. Elastic material The first seal 30 covers the inner and outer circumferential surfaces and the axially inner end face of the cylindrical portion 32 of the slinger body 29 over the entire circumference. In this example, the first seal 30 is bonded and fixed to the inner and outer circumferential surfaces and the axially inner end face of the cylindrical portion 32 by vulcanization molding. The first seal 30 also has a first engagement protrusion 38 having a triangular cross-sectional shape that protrudes radially inward from the axially inner end portion over the entire circumference.

[0047] The first seal material 30 has its inner circumferential surface fitted onto the cylindrical surface portion 15 of the hub 3 with a tightening margin, and the first engagement protrusion 38 is engaged with the engagement recess 17. In this example, the first engagement protrusion 38 is engaged with the engagement recess 17 by a so-called snap-fit. In other words, the first engagement protrusion 38 is engaged with the engagement recess 17 elastically (snap-fit ​​type).

[0048] The second seal 31 is bonded and fixed to the axially outer surface of the standing plate portion 33 of the slinger body 29, and the axially outer surface abuts against the axially inner surface of the rotating flange 10. The second seal 31 is formed in a hollow circular flat plate shape from an elastic material such as an elastomer like rubber. Specifically, in this example, the second seal 31 is bonded and fixed (adhered) to the axially outer surface of the outer diameter side flat plate portion 36 of the standing plate portion 33 by vulcanization molding, and the axially outer surface abuts against the flat surface portion 14 of the rotating flange 10 without any gap. This prevents moisture from entering from the gap between the axially inner surface of the rotating flange 10 and the axially outer surface of the standing plate portion 33 of the slinger 27.

[0049] Seal ring 28 has a plurality of seal lips 39a, 39b, 39c (three in the illustrated example) whose tip ends are in sliding contact with or closely facing the axial inner surface of upright portion 33 of slinger 27 or the outer circumferential surface of first sealing material 30. In this example, seal ring 28 includes a core metal 40 fixedly fitted into the axial outer end portion of outer ring 2, and a seal body 41 having a plurality of seal lips 39a to 39c and fixedly joined to core metal 40.

[0050] The core bar 40 is formed into an annular shape by bending a metal plate such as a soft steel plate. The core bar 40 includes a fitting tubular portion 42, an outward flange portion 43, and a bent plate portion 44.

[0051] The fitting tubular portion 42 is configured in a cylindrical shape, and its outer peripheral surface is press-fitted and fixed to the inner peripheral surface of the axially outer end portion of the outer ring 2 .

[0052] The outward flange portion 43 bends at a right angle from the axially outer end of the fitting cylindrical portion 42 toward the radially outer side, and its axially inner surface abuts against the axially outer end face of the outer ring 2 via a part of the base 45 of the seal body 41 described later.

[0053] The bent plate portion 44 is folded back in a substantially U-shape from the axially inner end of the fitting cylinder portion 42 toward the radially inner side and the axially outer side, and further, the tip portion is bent toward the radially inner side.

[0054] The seal body 41 is made of an elastic material such as an elastomer like rubber, and is fixed (bonded) to the core metal 40 by vulcanization molding. The seal body 41 includes a base portion 45, a plurality of seal lips 39a, 39b, 39c, and a dam portion .

[0055] The base 45 is joined and fixed to the core bar 40 so as to cover the radially outer end, outer peripheral surface and axially outer surface of the axially inner surface of the outward flange portion 43, the inner peripheral surface of the fitting tube portion 42, and the radially inner end of the axially outer surface, inner peripheral surface and axially inner surface of the bent plate portion 44.

[0056] Each of the seal lips 39a, 39b, 39c extends from the base 45 toward the axially inner surface of the standing plate portion 33 of the slinger 27 or the outer circumferential surface of the first seal material 30. In this example, the radially outermost seal lip 39a has its tip portion in sliding contact with the axially inner surface of the outer diameter side flat plate portion 36 of the standing plate portion 33 over the entire circumference, the radially second outermost seal lip 39b has its tip portion in sliding contact with the axially inner surface of the inner diameter side flat plate portion 34 of the standing plate portion 33 over the entire circumference, and the radially innermost seal lip 39c has its tip portion closely facing the outer circumferential surface of the first seal material 30 over the entire circumference, thereby forming a labyrinth seal 50 between the tip portion of the seal lip 39c and the outer circumferential surface of the first seal material 30.

[0057] The dam portion 46 protrudes radially outward from a portion of the base portion 45 that covers the outer peripheral surface of the outward flange portion 43. The dam portion 46 has a radially outer end that protrudes radially outward from an axially outer end face of the outer ring 2, and has an outer peripheral surface that closely faces the inner peripheral surface of the eaves portion 37 of the slinger 27. This blocks moisture that adheres to the outer peripheral surface of the outer ring 2 and attempts to flow along the outer peripheral surface of the outer ring 2 to enter the sliding contact portion between the radially outermost seal lip 39a and the axially inner surface of the standing plate portion 33, and also forms a labyrinth seal 47 between the outer peripheral surface of the dam portion 46 and the inner peripheral surface of the eaves portion 37.

[0058] Of the pair of seal devices 5a, 5b, the seal device 5b that closes the axially inner opening of the rolling element installation space 26 is configured, for example, by a combination seal ring. Specifically, the axially inner seal device 5b can include a slinger having a substantially L-shaped cross section and fitted and fixed to the axially inner end of the hub 3, and a seal ring having at least one seal lip whose tip is in sliding contact with the surface of the slinger over the entire circumference and fitted and fixed to the axially inner end of the outer ring 2.

[0059] In the case of a hub unit bearing for a driven wheel, a bottomed cylindrical cover fixed to the axially inner end of the outer ring can be used as the axially inner sealing device instead of or in addition to the combined seal ring.

[0060] The hub unit bearing 1 of this example is assembled as follows. First, with the axially inner end of the tubular portion 32 of the slinger body 29 elastically expanded in diameter, the inner circumferential surface of the axially outer portion of the first seal material 30 is fitted from the axially inner side to the cylindrical surface portion 15 of the hub 3, and the axially outer side surface of the second seal material 31 is abutted against the flat surface portion 14 of the rotating flange 10. Thereafter, the tubular portion 32 is elastically restored to its original state, so that the entire inner circumferential surface of the first seal material 30 is fitted to the cylindrical surface portion 15 and the first engaging protrusion 38 is engaged (snapped) into the engaging recess 17.

[0061] The subsequent assembly procedures are the same as those of conventional hub unit bearings. 、6b The rolling elements 4a, 4b are arranged radially inside the hub ring 21 while being held by the cages 25a, 25b, and a seal ring 28 is fitted and fixed to the axially outer end, and then the outer ring 2 is arranged around the hub ring 21. Thereafter, the inner ring 20 is fitted onto the small diameter portion 22 of the hub ring 21 and a crimped portion 23 is formed, and the inner ring 20 and the hub ring 21 are joined and fixed to form the hub 3. Finally, an axially inner seal device 5b is installed between the inner peripheral surface of the axially inner end of the outer ring 2 and the outer peripheral surface of the axially inner end of the hub 3.

[0062] The process for assembling the hub unit bearing 1 can be modified as appropriate as long as no contradiction occurs.

[0063] As described above, in the hub unit bearing 1 of this embodiment, the tubular portion 32 of the slinger body 29 made of a metal plate such as a stainless steel plate is disposed around the cylindrical surface portion 15 of the hub 3, and the inner peripheral surface of the first seal member 30 made of a flexible material that covers the inner peripheral surface of the tubular portion 32 is fitted onto the cylindrical surface portion 15. In other words, the tubular portion 32 of the slinger body 29 is fitted onto the cylindrical surface portion 15 via the first seal member 30. Therefore, when the slinger 27 is attached to a predetermined position on the hub 3 (around the cylindrical surface portion 15), it is possible to prevent the inner peripheral surface of the tubular portion 32 from being scuffed or the standing plate portion 33 from being undesirably deformed.

[0064] Also, in this example, the tubular portion 32 of the slinger body 29 is not folded back into a U-shape, as in the fitting tubular portion of the sealing device described in JP 2017-129197 A. This not only makes it easier to press the slinger body 29 (making it less likely to become brittle during processing), but also makes it possible to prevent the slinger body 29 from cracking due to the action of large residual stress caused by work hardening after the slinger body 29 is attached to the hub 3 (the occurrence of so-called placement cracks).

[0065] In this example, the inner peripheral surface of the first seal member 30, which is bonded and fixed to the tubular portion 32 of the slinger body 29, is fitted onto the cylindrical surface portion 15, and the axially outer surface of the second seal member 31, which is bonded and fixed to the axially outer surface of the (outer diameter side flat portion 36 of) the standing plate portion 33, is abutted against the axially inner surface (flat surface portion 14) of the rotating flange 10. This makes it possible to increase the frictional force acting between the surface of the hub 3 and the surface of the slinger 27, thereby preventing relative displacement (creep and axial displacement) of the slinger 27 with respect to the hub 3. Furthermore, even if a moment load based on a road surface reaction force is applied to the rotating flange 10 and the rotating flange 10 is deformed so as to fall (tilt) in the axial direction, this deformation can be absorbed to some extent by the elastic deformation of the first seal member 30 and / or the second seal member 31, thereby preventing axial displacement of the slinger 27 with respect to the hub 3.

[0066] Furthermore, in this example, first engagement protrusions 38 formed on the entire circumference of slinger 27 are engaged with engagement recesses 17 formed on the entire outer circumferential surface of hub 3. This also makes it possible to effectively prevent axial displacement of slinger 27 relative to hub 3.

[0067] [Second Example of the Implementation Form] FIG. 3 shows a second embodiment of the present invention. In this embodiment, the first seal member 30a of the slinger 27a has a first engagement protrusion 38a having a triangular cross-sectional shape that protrudes from the axial middle portion toward the radial inside over the entire circumference. Therefore, the first engagement protrusion 38a and the cylindrical portion 32 of the slinger body 29 overlap in the radial direction. This increases the engagement force between the first engagement protrusion 38a and the engagement recess 17 of the hub 3, and more reliably prevents the axial displacement of the slinger 27a relative to the hub 3. In addition, the tip of the radially innermost seal lip 39c can be brought into sliding contact with the outer circumferential surface of the cylindrical portion 32 of the slinger body 29. The configuration and effects of the other parts are the same as those of the first embodiment.

[0068] [Third Example of the Implementation Form] 4 shows a third embodiment of the present invention. In this embodiment, the hub 3a has a cylindrical surface portion 15a on the outer peripheral surface of the axially outer inner ring shoulder portion 16 adjacent to the axially outer side of the axially outer inner ring raceway 9a, and has an engagement recess 17a over the entire circumference in the axially intermediate portion of the cylindrical surface portion 15a. The engagement recess 17a has an axial width dimension that decreases radially inward. but It has a decreasing trapezoidal cross-sectional shape.

[0069] The hub 3a has a flange-side engagement recess 48 that is recessed axially outward on the flat surface 14a of the rotating flange 10a over the entire circumference. The flange-side engagement recess 48 has a trapezoidal cross-sectional shape whose radial width increases axially inward.

[0070] The first seal member 30b constituting the slinger 27b covers the entire inner peripheral surface of the axially intermediate portion of the cylindrical portion 32 of the slinger body 29. The first seal member 30b has a width dimension in the axial direction that decreases toward the radially inner side. but The first seal member 30b has a trapezoidal cross-sectional shape that becomes smaller, and its radially inner portion is engaged with the engaging recess 17a of the hub 3a. That is, in this example, the radially inner portion of the first seal member 30b constitutes the first engaging protrusion 38b.

[0071] The second seal material 31a is bonded and fixed to the axially outer surface of the standing plate portion 33 of the slinger body 29. The second seal material 31a has a trapezoidal cross-sectional shape whose radial width dimension increases toward the axially inner side, and the axially outer portion is engaged with the flange side engagement recess 48 of the hub 3a. That is, in this example, the axially inner portion of the second seal material 31a constitutes the second engagement protrusion 49.

[0072] In this example, the first engaging protrusion 38b is formed by a radially inner portion of the first seal member 30b having a trapezoidal cross-sectional shape. Therefore, compared to the structures of the first and second examples of the embodiment, the first engaging protrusion 38b that engages with the engaging recess 17a of the hub 3a can be made larger (the cross-sectional area can be increased). As a result, the effect of preventing axial displacement of the slinger 27b relative to the hub 3a due to the engagement between the engaging recess 17a and the first engaging protrusion 38b can be further improved.

[0073] In this example, the first engaging protrusion 38b, which is the radially inner portion of the first seal member 30b having a trapezoidal cross-sectional shape, is engaged with the engaging recess 17a, thereby ensuring a large radial thickness dimension and volume of the first seal member 30b interposed between the cylindrical portion 32 of the slinger body 29 and the hub 3a. In addition, the second engaging protrusion 49, which is the axially outer portion of the second seal member 31a having a trapezoidal cross-sectional shape, is engaged with the flange-side engaging recess 48, thereby ensuring a large axial thickness dimension and volume of the second seal member 31a interposed between the upright portion 33 of the slinger body 29 and the hub 3a. Therefore, when the rotating flange 10a is deformed so as to fall in the axial direction due to a moment load based on the road surface reaction force, the amount of this deformation that can be absorbed by the elastic deformation of the first seal member 30b and / or the second seal member 31a can be increased. Therefore, the axial displacement of the slinger 27 relative to the hub 3 can be more reliably prevented. The configuration and the effects of other parts are similar to those of the first and second embodiments. [Explanation of symbols]

[0074] 1, 1a Hub unit bearing 2 Outer ring 3, 3a hub 4a, 4b Rolling elements 5a, 5b Sealing device 6a, 6b Outer raceway 7 Stationary Flange 8 Support hole 9a, 9b Inner raceway 10, 10a Rotating flange 11 Pilot Division 12 Mounting hole 13 Stud 14, 14a Flat surface part 15, 15a Cylindrical surface part 16 Inner ring shoulder 17, 17a Engagement recess 18 Corner R 19 Spline hole 20. Inner Circle 21 Hub wheel 22 Small diameter section 23 Crimping part 24 Step surface 25a, 25b retainer 26 Rolling element installation space 27, 27a, 27b Slinger 28 Seal ring 29 Slinger body 30, 30a, 30b First sealing material 31, 31a Second sealing material 32 Cylindrical section 33 Vertical board 34 Inner diameter flat plate part 35 Inclined plate section 36 Outer diameter side flat plate part 37 Eaves 38, 38a, 38b 1st engagement protrusion 39a, 39b, 39c Seal lip 40 Core wire 41 Seal body 42 Fitting cylinder part 43 Outward flange 44 Bent plate section 45 Base 46 Weir 47 Labyrinth Seal 48 Flange side engagement recess 49 Second engagement protrusion 50 Labyrinth Seal

Claims

1. an outer ring having a double row outer ring raceway on an inner circumferential surface; a hub having a rotating flange provided at a portion located axially outward from the outer ring and protruding radially outward, a double row inner ring raceway provided on an outer peripheral surface, and an engaging recess provided on an outer peripheral surface between the rotating flange and an axially outer one of the double row inner ring raceways in the axial direction; a plurality of rolling elements disposed between the double row outer ring raceways and the double row inner ring raceways so as to be freely rollable; a seal device having a slinger and a seal ring, and closing an axially outer opening of a rolling element installation space that exists between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub, The slinger is a slinger body made of a metal plate, the slinger body including a cylindrical portion, the entire inner peripheral surface of which is disposed radially apart from the axially outer periphery of the outer peripheral surface of the hub between the rotating flange and the axially outer inner ring raceway, and a standing portion bent radially outward from the axially outer end of the cylindrical portion and the entire axially outer side surface of which is disposed axially apart from the axially inner surface of the rotating flange; a first seal member made of an elastic material, the first seal member including a first engaging protrusion that engages with the engaging recess, the first seal member being fixed to the cylindrical portion so as to cover at least a portion of an inner peripheral surface of the cylindrical portion in the axial direction, and the first seal member having an inner peripheral surface that is fitted onto a portion of an outer peripheral surface of the hub between the rotating flange and an inner ring raceway on the axial outer side; a second seal member made of an elastic material, the second seal member being joined and fixed to an axially outer surface of the upright portion, the axially outer surface of the second seal member being abutted against an axially inner surface of the rotating flange, The seal ring has at least one seal lip whose tip portion is in sliding contact with or closely opposed to the axially inner surface of the upright portion. Hub unit bearing.

2. the hub has a flange-side engagement recess on an axially inner surface of the rotation flange, the flange-side engagement recess being recessed axially outward, the second seal member has a second engaging protrusion that engages with the flange-side engaging recess; The hub unit bearing according to claim 1 .

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