JP2017219120A - Bearing device for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel which has excellent performance, secures muddy water resistant performance of a sealing device and furthermore is inexpensive by materializing reduction in grinding cost of an outer ring.SOLUTION: A bearing device 10 for a wheel is provided in which a combined seal is assembled in an inner-side opening portion of an annular space 91 formed between an outer ring 14 and an inner shaft 83, the combined seal being obtained by combining: a seal ring 39 in which a core metal and a lip of an elastic body is formed as one body and which is fixed to the outer ring; and a slinger 40 fixed to the inner shaft 83. The outer ring 14 comprises a cylindrical faucet portion 27 projecting to an inner side from a flange portion 84 and fitted to a vehicle member, and an inner-side mounting face 29 is formed in an outer periphery of the faucet portion 27 by grinding the outer periphery. The seal ring 39 is externally fitted onto the inner-side seal mounting face 29, and the grinding work is not performed on an inner circumferential surface 32 radially opposed to a shoulder 36 of the inner ring, of the faucet portion 27.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hub unit type wheel bearing device.

In the vehicle, a wheel bearing device 80 as shown in FIG. 4 is used in order to rotatably support the wheel (Patent Document 1).
The wheel bearing device 80 includes an outer ring 82 fixed to the knuckle 81 and a rotatable inner shaft 83 that is disposed coaxially with the outer ring 82. The inner shaft 83 includes a hub shaft 85 and an inner ring 86 that is press-fitted into one of the shaft ends. A hub flange 87 for attaching a wheel (not shown) is attached to the other shaft end of the hub shaft 85. It is integrally formed. In the wheel bearing device 80, the side on which the wheel is attached is the outside of the vehicle, and in FIG. 4, the left side is called the outer side and the right side is called the inner side.

Double row outer raceway surfaces 88 and 88 are formed on the inner periphery of the outer ring 82, and double row inner raceway surfaces 89 a and 89 b are formed on the outer periphery of the inner shaft 83. A plurality of balls 90 are rotatably incorporated between the outer raceway surfaces 88 and 88 and the inner raceway surfaces 89a and 89b. Each raceway surface is finished into a smooth surface with a small surface roughness by grinding. Each raceway surface is filled with grease, and the inner shaft 83 can smoothly rotate with respect to the outer ring 82.
An annular space 91 formed between the inner periphery of the outer ring 82 and the outer periphery of the inner shaft 83 is open on both sides in the axial direction. Sealing devices 92 and 93 are attached to the respective openings to prevent foreign matters such as muddy water from entering the annular space 91.

A combination seal in which a slinger 94 and a seal ring 95 are combined as shown in FIG. 5 is used for the sealing device 93 mounted in the opening on the inner side of the vehicle. The slinger 94 is made of a stainless steel plate having an L-shaped axial section, and is fixed to the outer peripheral surface of the inner ring 86. In the seal ring 95, a cored bar 96 made of carbon steel plate and an elastic lip 97 are integrally formed, and the cored bar 96 is fitted into a seal mounting surface 99 formed on the inner periphery of the outer ring 82. It is fixed in the state.
By using a combination seal, the interference of the lip 97, particularly the interference in the axial direction, can be assembled accurately, and the sealing device 93 can appropriately prevent the entry of foreign matter.

  A single seal ring is incorporated in the sealing device 92 that is mounted in the opening on the outer side of the vehicle. The sealing device 92 includes a cored bar 98 having an L-shaped cross section in the axial direction (see FIG. 4), and a seal mounting surface 24 (hereinafter simply referred to as “outer side seal mounting”) formed on the outer circumference of the outer ring 82. It is fixed in a state of interference fit.

  As described above, in the sealing devices 92 and 93 attached to the wheel bearing device 80, the core bars 96 and 98 made of carbon steel plates are fitted to the carbon steel outer ring 82, and the fitting portions are It is a metal-to-metal fitting. For this reason, when the surface roughness of the fitting surface is large, there is a possibility that a slight gap is generated and water enters. For this reason, the seal mounting surfaces 24 and 99 on the inner periphery of the outer ring 82 are finished to smooth surfaces with small surface roughness by grinding.

JP 2002-227857 A

In the wheel bearing device 80, the raceway surfaces 88, 89a, and 89b are precisely finished to reduce noise during vehicle travel, and the muddy water resistance performance of the sealing devices 92 and 93 is ensured to be smooth over a long period of time. It is required to maintain rotation.
For this reason, in the outer ring 82, the double row outer raceway surfaces 88, 88 are ground simultaneously with a single grindstone, thereby ensuring mutual coaxiality with high accuracy. Also, the seal mounting surfaces 24 and 99 are ground at the same time as the outer raceway surface 88, and a highly accurate coaxiality is ensured. As a result, the interference between the slinger 94 and the lip 97 is uniform over the entire circumference, so that the muddy water resistance can be increased.

However, in the case where the seal mounting surfaces 24 and 99 and the outer raceway surfaces 88 and 88 respectively formed at the end portions in the axial direction are simultaneously ground with a single grindstone, the axial dimension of the grindstone must be increased. Without it, the cost of the grindstone increases. Further, since the inner peripheral shape of the outer ring 82 is complicated, an expensive rotary dress is required when the outer shape of the grindstone is formed, and the cost of grinding is further increased.
Thus, since the cost required for grinding the inner periphery of the outer ring is high, the manufacturing cost of the outer ring 82 is increased, and the manufacturing cost of the wheel bearing device 80 is high.

  An object of the present invention is to provide a wheel bearing device that is inexpensive and excellent in performance by reducing the grinding cost of the outer ring while securing the muddy water resistance of the sealing device.

  One aspect of the present invention includes an outer ring having double rows of outer raceways on the inner circumference and a flange portion on the outer circumference, which is fixed to the vehicle member and does not rotate, and one inner raceway on the outer circumference and at the shaft end. A hub flange for mounting a wheel and an inner ring having the other inner raceway surface on the outer periphery are integrally formed, and a rotatable inner shaft, the outer raceway surface facing each other in the radial direction, and the double row inner raceway surface A plurality of rolling elements disposed between the outer ring and the inner shaft, and an inner side opening of the annular space formed between the outer ring and the inner shaft has a core metal and a lip of an elastic body. Is a bearing device for a wheel incorporating a combination seal in which a seal ring that is integrally formed and fixed to the outer ring and a slinger that is fixed to the shoulder of the inner ring is incorporated, and the outer ring includes the flange portion Protrude more to the inner side, A cylindrical inner part fitted to the vehicle member is provided, and an inner side seal mounting surface is formed by grinding the outer periphery of the inner part, and the inner side seal mounting surface is formed on the inner side seal mounting surface. The seal ring has an outer casing, and in the spigot portion, the inner peripheral surface facing the shoulder of the inner ring in the radial direction is not ground.

  The present invention can reduce the grinding cost of the outer ring while ensuring the muddy water resistance of the sealing device, and thus can provide a wheel bearing device that is inexpensive and excellent in performance.

It is a principal part enlarged view of one Embodiment of the wheel bearing apparatus concerning this invention. It is a conceptual diagram explaining the method of grinding the inner periphery of the outer ring | wheel of this embodiment. It is a conceptual diagram explaining the method of grinding the inner periphery of the conventional outer ring | wheel. It is sectional drawing of the conventional wheel bearing apparatus. It is sectional drawing of the sealing device with which the inner side of the conventional wheel bearing apparatus is mounted | worn.

Embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an enlarged view of a main part of an embodiment (hereinafter, this embodiment) of a wheel bearing device 10 according to the present invention, and a sealing device 12 (hereinafter simply referred to as “inner side sealing device” mounted on the inner side). )). The wheel bearing device 10 of this embodiment is characterized by the form of the inner side sealing device 12 and the form of the outer ring 14 to which the inner side sealing device 12 is attached. Since other forms are the same as those of the conventional wheel bearing device 80, portions common to the conventional structure will be described with the same reference numerals with reference to FIG.
In the following description, the direction of the axis m is referred to as the axial direction, the direction orthogonal to the axial direction is referred to as the radial direction, and the direction of circling around the axis m is referred to as the circumferential direction.

  As shown in FIG. 4, the wheel bearing device 10 of this embodiment includes an outer ring 14, an inner shaft 83, a plurality of balls 90 that are rolling elements, and sealing devices 12 and 92.

The form of the outer ring 14 will be described with reference to FIG.
The outer ring 14 is manufactured by hot forging high carbon steel or the like, and a substantially cylindrical cylindrical portion 16 and a flange portion 84 formed on the outer periphery thereof are integrally formed. The flange portion 84 extends radially outward from approximately the center in the axial direction at a plurality of locations on the outer periphery of the cylindrical portion 16, and is connected to each other by ribs 17 in the circumferential direction.
A bolt hole 18 penetrating in the axial direction is formed in the flange portion 84, and a bolt (not shown) is inserted into the bolt hole 18 so that the outer ring 14 is fixed to a knuckle 81 that is a vehicle member. . The side surface of the flange portion 84 and the side surface of the rib 17 are formed flush with each other in a direction orthogonal to the axis m, and are in contact with the mounting surface of the knuckle 81.

Two rows of outer raceway surfaces 88 and 88 are formed on the inner periphery of the cylindrical portion 16 at substantially the center in the axial direction. The outer raceway surfaces 88 and 88 each have an arc cross section in the axial direction and are formed in an annular shape coaxial with the axis m.
The outer raceways 88 and 88 are connected to each other in the axial direction by a small-diameter shoulder 20, and large-diameter shoulders 21 and 22 are formed on the opposite side of the small-diameter shoulder 20, respectively. Each shoulder 20, 21, 22 is a cylindrical surface coaxial with the axis m. Thus, in the axial section, the positions of the centers of the outer raceways 88 and 88 (referred to as the center of the arc) with respect to the center of curvature (not shown) are inclined in a direction approaching each other radially outward.
The outer raceway surfaces 88 and 88 are heat treated to increase the surface hardness to about 60 HRC, and then subjected to grinding to finish the surfaces to be smooth.

An outer side seal mounting surface 24 is formed on the inner peripheral side of the outer side end of the cylindrical portion 16. The outer side seal mounting surface 24 is a cylindrical surface coaxial with the axis m, and is formed from the outer side end surface 25 of the cylindrical portion 16 to a predetermined depth. An outer side sealing device 92 is assembled to the outer side seal mounting surface 24. The outer side sealing device 92 has a cored bar 98 having an L-shaped cross section in the axial direction, and an elastic lip is formed integrally with the cored bar 98. The metal core 98 is fitted into the outer side seal mounting surface 24 in an interference fit state, and the outer side sealing device 92 is fixed.
The outer side seal mounting surface 24 is finished to a smooth surface with a small surface roughness by grinding. For this reason, infiltration of water or the like from the fitting portion between the cored bar 98 and the outer side seal mounting surface 24 can be prevented.

The form of the inner side end portion of the outer ring 14 will be described with reference to FIG.
In the outer ring 14, the cylindrical portion 16 protrudes from the flange portion 84 toward the inner side in the axial direction. Since the protruding portion 27 is fitted to the vehicle member when the hub unit is attached to the vehicle, it is referred to as an “inlay portion” in the following description.
The outer periphery of the inner part 27 is a cylindrical surface coaxial with the axis m, and is an inner side seal attachment surface 29 to which the inner side sealing device 12 is attached. The inner side seal mounting surface 29 is ground to be a smooth surface with a small surface roughness. For this reason, when the inner side sealing device 12 is fitted together, water or the like can be prevented from entering from the fitting surface. The form of the inner side sealing device 12 will be described later.

In the inlay portion 27, a concave portion 31 that accommodates a part of the inner side sealing device 12 is formed on the inner periphery. The recess 31 has a cylindrical shape coaxial with the axis m. The inner peripheral surface 32 is formed to a predetermined depth from the inner side end surface 26 of the cylindrical portion 16, and is connected to the large-diameter shoulder 22 of the outer raceway surface 88 at the radial side surface 33.
In the recessed part 31, the inner side sealing device 12 is accommodated with a gap. Since the inner side sealing device 12 is fixed to the outer ring 14 on the outer peripheral side of the spigot portion 27, the inner peripheral surface 32 of the recess 31 does not contact the inner side sealing device 12. For this reason, it is not necessary to grind the inner peripheral surface 32, and the inner peripheral surface 32 may be a forged skin when it is forged, or may be turned.

The description will be given with reference to FIGS. 4 and 5 again.
As shown in FIG. 4, the inner shaft 83 has a configuration in which a hub shaft 85 and an inner ring 86 are combined together. The form of the inner shaft 83 is the same as that of the conventional structure, and will be described briefly.

The hub shaft 85 is manufactured by hot forging high carbon steel, and has a stepped cylindrical shaft portion 78 extending in the direction of the axis m, and a direction perpendicular to the axis m connected to the shaft end. A disk-shaped hub flange 87 extending in the direction is integrally formed. One inner raceway surface 89a is formed on the shaft portion 78 at the axial center of the outer periphery. The inner raceway surface 89a has an arc-shaped cross section in the axial direction and is formed in an annular shape coaxial with the axis m. A large-diameter shoulder 35 is formed on the outer side of the inner raceway surface 89a, and the axial cross section is connected to the hub flange 87 through an R-shaped surface. A small-diameter stepped portion is formed at the inner side end of the shaft portion 78, and the inner ring 86 is assembled in a state of an interference fit.
The inner raceway surface 89a is heat treated to increase the surface hardness to about 60 HRC and then finished to a smooth surface with a small surface roughness by grinding.

The inner ring 86 is made of bearing steel, and the other inner raceway surface 89b is formed at substantially the center in the axial direction of the outer periphery. The inner raceway surface 89b has an arc cross section in the axial direction and is formed in an annular shape coaxial with the axis m. A large-diameter shoulder 36 is formed on the inner side of the inner raceway surface 89b (see FIG. 5). The shoulder 36 has a cylindrical shape coaxial with the axis m, and its inner end is connected to the large end surface 77 of the inner ring 86.
The inner raceway surface 89b and the large-diameter shoulder 36 are heat-treated to increase the surface hardness to about 60 HRC, and then finished to a smooth surface with a small surface roughness by grinding.

A plurality of balls 90 are rotatably integrated between the double-row outer raceway surfaces 88 and 88 and the double-row inner raceway surfaces 89a and 89b that are opposed to each other in the radial direction. The balls 90 in each row are arranged at equal intervals in the circumferential direction by the cage 100. Grease is enclosed in an annular space 91 formed between the outer ring 14 and the inner shaft 83 in order to lubricate each raceway surface. Thus, the wheel attached to the hub flange 87 is rotatably supported by the wheel bearing device 10.
The annular space 91 is open on both sides in the axial direction, and the sealing devices 12 and 92 are attached to the respective openings.

  The inner side sealing device 12 will be described with reference to FIG. The inner side sealing device 12 includes a seal ring 39 and a slinger 40.

The seal ring 39 includes a metal core 41 and a plurality of seal lips 43, 44, and 45 made of an elastic body.
The core metal 41 is formed in an annular shape by press-molding a rolled steel plate made of a non-rusting metal material such as stainless steel. The cored bar 41 is a cylindrical part 47 fitted into the outer ring 14 in a cylindrical shape, a first step part 48 in which an inner side end part of the cylindrical part 47 is bent radially inward, The second step portion 49 is further bent toward the cylindrical portion 47 at a substantially inner peripheral end position. The seal lips 43, 44 and 45 are bonded to the second step portion 49. In this way, the seal lips 43, 44, 45 can be arranged on the inner side (the side closer to the outer raceway surface 88) of the inner side end surface 26 of the outer ring 14, so that an increase in axial dimension is suppressed and the wheel bearing device 10 is suppressed. Can be made compact. For this reason, the mounting property to a vehicle becomes favorable.
The second step portion 49 has an axial cross-sectional shape that is inclined in a direction of reducing the diameter from the inner side toward the outer side, but is not limited thereto, and is a cylindrical surface formed in parallel with the axis m. There may be. In this case, there is a gap between the outer periphery of the cylindrical surface and the inner peripheral surface 32 of the recess 31.

In the seal ring 39, reference numeral 43 denotes a grease lip, which is in contact with the outer periphery of the slinger 40 with a small interference to prevent the grease sealed in the annular space 91 from flowing out.
A radial lip 44 is in sliding contact with the outer periphery of the slinger 40 and prevents foreign matter from entering the annular space 91 and prevents the grease from flowing out of the annular space 91.
Reference numeral 45 denotes an axial lip that is in sliding contact with the flange portion 42 of the slinger 40 to prevent foreign matters such as muddy water and dust from reaching the radial lip 44 directly.
A rubber material such as nitrile rubber or acrylic rubber is used as the material of each seal lip 43, 44, 45. Each of the seal lips 43, 44, 45 is vulcanized with a high-temperature mold and is vulcanized and bonded to the core metal 41.

The slinger 40 is formed in an annular shape by press-molding a cold-rolled steel plate such as SPCC. The slinger 40 is L-shaped in cross section, and is integrally formed with a fixed portion extending in a cylindrical shape in the axial direction and a flange portion 42 whose one end in the axial direction is bent at a right angle and expands radially outward. Yes.
An encoder 51 formed of a rubber magnet is affixed to the collar portion 42. The encoder 51 is disc-shaped and is coaxially attached to the side surface of the flange 42 opposite to the fixed portion by vulcanization adhesion or the like. The surface of the encoder 51 is magnetized, and S poles and N poles are alternately formed in the circumferential direction.

When assembling the inner side sealing device 12 to the wheel bearing device 10, the seal ring 39 and the slinger 40 with the encoder 51 attached are simultaneously assembled in the combined state as shown in FIG. At this time, although not shown, using a jig having a plane orthogonal to the axis m, the first step portion 48 of the seal ring 39 and the inner side surface of the encoder 51 are simultaneously pressed in the axial direction. .
The inner diameter dimension of the cylindrical portion 47 of the seal ring 39 is slightly smaller than the outer diameter dimension of the inner side seal mounting surface 29 formed on the outer periphery of the inner portion 27 of the outer ring 14. For this reason, the cylindrical part 47 is assembled | attached in the state of interference fit. In addition, the slinger 40 is assembled to the large-diameter shoulder 36 of the inner ring 86 in an interference fit state.
The inner side seal mounting surface 29 and the large-diameter shoulder 36 are ground. For this reason, it is possible to prevent intrusion of water or the like from the fitting portion between the seal ring 39 and the inner-side seal mounting surface 29 and the fitting portion between the slinger 40 and the large-diameter shoulder 36.

  Thus, in the wheel bearing device 10 of the present embodiment, a combination seal in which the seal ring 39 and the slinger 40 are combined is mounted as an inner side sealing device. However, since the seal ring 39 is fixed on the outer periphery of the spigot portion 27, the inner peripheral surface 32 of the recess 31 formed on the inner periphery of the spigot portion 27 does not contact the inner side sealing device 12. For this reason, in the inlay part 27, the grinding process is not given to the internal peripheral surface 32 which opposes the shoulder 36 where the slinger 40 is fixed to radial direction.

  Moreover, since the axial direction dimension of the inlay part 27 is set comparatively large, the axial direction dimension of the inner side seal attachment surface 29 formed in the outer periphery can be enlarged. Thereby, the area which the metal core 41 and the inner side seal attachment surface 29 fit can be enlarged. For this reason, infiltration of water or the like from the mating surface can be effectively prevented.

  The wheel bearing device 10 of this embodiment is fitted to a knuckle 81 made of carbon steel in a state where the inner side sealing device 12 is fitted to the inner side end of the outer ring 14. Since the spigot part 27 of the outer ring 14 is covered with the cored bar 41 made of a non-rusting metal material, the attachment hole of the knuckle 81 and the spigot part 27 of the outer ring 14 do not directly contact each other. For this reason, even if it is used over a long period of time, rust does not occur in the fitting portion.

In the conventional wheel bearing device 80, the spigot portion 27 of the outer ring 14 is directly fitted into the mounting hole of the knuckle 81. For this reason, muddy water or the like enters the fitting portion and rusts. Therefore, when used for a long time, the fitting surface is fixed by rust, and it becomes difficult to remove the wheel bearing device 80 during vehicle maintenance. there were.
On the other hand, in the wheel bearing device 10 of the present embodiment, since such a problem does not occur, there is an advantage that vehicle maintenance becomes easy.

Next, the grinding method of the outer ring 14 of this embodiment will be described.
FIG. 2 is a conceptual diagram illustrating a method for grinding the inner periphery of the outer ring 14.
In the outer ring 14 of the present embodiment, the double row outer raceway surfaces 88 and 88 and the outer side seal mounting surface 24 are simultaneously ground by a single grindstone 53. By processing simultaneously with the single grindstone 53, the mutual coaxiality of the double-row outer raceway surfaces 88 and 88 and the outer side seal mounting surface 24 can be ensured with high accuracy.
As a result, it is possible to reduce abnormal noise during traveling of the vehicle and increase the muddy water resistance of the outer side sealing device 92.

  At the time of grinding, the outer ring 14 is mounted on the grinding machine. At this time, the outer side end face 25 of the outer ring 14 is attracted to the magnet flange 67 of the grinding machine. The grinding machine operates and the outer ring 14 rotates together with the magnet flange 67. The outer ring 14 is guided by a shoe 68 that contacts the outer periphery of the spigot portion 27. Although not shown, the shoes 68 are installed in two different directions in the circumferential direction and are in contact with the outer periphery of the spigot portion 27, respectively. As a result, the outer ring rotates accurately around a predetermined axis. That is, the inner side seal attachment surface 29 formed on the outer periphery of the spigot portion 27 is a reference surface for grinding. In this state, the grindstone 53 is inserted into the inner peripheral side of the outer ring 14 and brought into contact in the radial direction for grinding.

  The grindstone 53 is integrally formed with an arc-shaped track grinding portion 54 for grinding the outer raceway surfaces 88, 88 and a cylindrical outer side mounting surface grinding portion 55 for grinding the outer side seal mounting surface 24. . At this time, only the track grinding portion 54 and the outer side mounting surface grinding portion 55 are in contact with the inner periphery of the outer ring 14, and other portions, for example, the cylindrical portion 56 that connects the two track grinding portions 54 are the inner periphery of the outer ring 14. Do not touch. Thus, the outer side seal mounting surface 24 and the outer raceway surfaces 88 and 88 are ground simultaneously.

  As can be understood from the above description, in the grindstone 53 used for grinding the inner periphery of the outer ring 14 of the present embodiment, the axial dimension L1 is generally from the outer side end surface 25 to the outer raceway surface 88 and the recess 31. It is equivalent to the dimension of the axial direction to the side surface 33 which connects.

A grinding method of the outer ring 82 (hereinafter simply referred to as “conventional outer ring”) used in the conventional wheel bearing device 80 will be described in comparison with the grinding method of the present embodiment. FIG. 3 is a conceptual diagram illustrating a conventional method for grinding the inner periphery of the outer ring 82. In FIG. 3, the same reference numerals are given to the structures common to FIG. 5.
In the conventional wheel bearing device 80, a combination seal is used as the inner side sealing device 93 (see FIG. 5). For this reason, in the conventional outer ring 82, unlike the outer ring 14 of the present embodiment, the seal mounting surface 99 is formed also on the inner periphery on the inner side.
As shown in FIG. 3, in the conventional outer ring 82, it is necessary to ensure the coaxiality between the outer race surfaces 88, 88 of the double row and the outer and inner seal mounting surfaces 24, 99 with high accuracy. For this reason, these surfaces are ground simultaneously with a single grindstone 60.

  At the time of grinding, the conventional outer ring 82 is mounted on a grinding machine in the same manner as the outer ring 14 of the present embodiment. When the magnet flange 67 of the grinding machine rotates, the conventional outer ring 82 is guided by a shoe 68 that abuts the outer periphery of the spigot portion 27 and rotates accurately around a predetermined axis. In this state, the grindstone 60 is inserted into the inner peripheral side of the conventional outer ring 82 and brought into contact in the radial direction for grinding.

  The grindstone 60 is integrally formed with a track grinding portion 54, an outer side mounting surface grinding portion 55, and an inner side mounting surface grinding portion 61. The track grinding portion 54 is an arc-shaped portion that grinds the outer track surfaces 88 and 88. The outer side mounting surface grinding portion 55 is a cylindrical portion that grinds the outer side seal mounting surface 24. The inner side mounting surface grinding part 61 is a cylindrical part that grinds the inner seal mounting surface 99. Thus, both the seal mounting surfaces 24 and 99 and the outer raceway surfaces 88 and 88 are ground simultaneously.

  As can be understood from the above description, in the grindstone 60 used for grinding the inner periphery of the conventional outer ring 82, the axial dimension L2 is approximately the axial dimension from the outer side end face 25 to the inner side end face 26. It is equivalent to the dimension.

On the other hand, in the wheel bearing device 10 of the present embodiment, as shown in FIG. 2, the dimension in the axial direction of the grindstone 53 used for grinding the outer ring 14 is L1, and the dimension in the axial direction is the grindstone. It is smaller than 60. This is because, in this embodiment, it is possible to eliminate the need for forming a seal mounting surface on the inner side inner periphery of the outer ring 14.
That is, in the conventional wheel bearing device 80, a sealing device 93 (see FIG. 5) in the form of a combination seal is used as a sealing device on the inner side. In this case, since the slinger 94 is fitted on the shoulder 36 of the inner ring 86, it is necessary to fix the seal ring 95 to the inner periphery of the outer ring 82 that faces the shoulder 36 in the radial direction. However, in this embodiment (see FIG. 1), the inner seal ring 39 is fitted to the outer periphery of the spigot portion 27, so that no seal mounting surface is required on the inner peripheral side of the spigot portion 27.
In addition, since the shoe 68 abuts on the outer periphery of the inlay portion 27 at the time of grinding of the inner periphery of the outer ring 14, the conventional outer ring 82 is similarly ground. Therefore, in the outer ring 14 of this embodiment, a new process is not required for assembling the seal ring 39, and the manufacturing cost does not increase.

Thus, in this embodiment, since the size of the grindstone 53 can be reduced, the cost of the grindstone 53 can be reduced, and the cost required for grinding can be reduced.
Furthermore, the grindstone 53 does not require the inner side mounting surface grinding portion 61 formed on the grindstone 60 that grinds the conventional outer ring 82, so that the shape of the outer periphery can be simplified. For this reason, since the manufacturing cost of a rotary dress can be reduced, the expense required for grinding can be further reduced.

And as explained above, by processing simultaneously with the single grindstone 53, it is possible to ensure the mutual coaxiality of the double-row outer raceway surfaces 88 and 88 and the outer side seal mounting surface 24 with high accuracy. it can. Further, since the outer raceway surfaces 88 and 88 and the outer side seal attachment surface 24 are processed on the basis of the inner side seal attachment surface 29, the coaxiality between the inner side seal attachment surface 29 and the outer raceway surfaces 88 and 88 is also improved. It is secured.
For this reason, in the wheel bearing device 10 of this embodiment, the muddy water resistance performance of the sealing devices 12 and 93 can be secured, and smooth rotation can be maintained over a long period of time.

As described above, in the wheel bearing device 10 of the present embodiment, the cost required for grinding the inner periphery of the outer ring 14 can be significantly reduced, and therefore the manufacturing cost of the outer ring 14 is reduced. As a result, it is possible to provide a wheel bearing device that is inexpensive and excellent in performance while ensuring the muddy water resistance of the sealing device.

(This embodiment) 10: Wheel bearing device, 12: Sealing device (inner), 14: Outer ring, 16: Cylindrical part, 24: Outer side seal mounting surface, 27: Inner part, 29: Inner side seal mounting surface, 31: recessed portion, 39: seal ring, 40: slinger, 47: cylindrical portion, 48: first step portion, 49: second step portion, 51: encoder, 53: grinding wheel, 54: orbit grinding portion, 55: outer Side mounting surface grinding part,
(Conventional structure) 60: Grinding wheel, 61: Inner side mounting surface grinding part, 68: Shoe, 80: Wheel bearing device, 81: Knuckle, 82: Outer ring, 83: Inner shaft, 84: Flange part, 85: Hub shaft 86: inner ring, 87: hub flange, 88: outer raceway surface, 89a, 89b: inner raceway surface, 90: ball, 91: annular space, 92: sealing device (outer), 93: sealing device (inner), 94 : Slinger, 95: Seal ring, 99: Seal mounting surface (inner)

Claims (4)

An outer ring having a double-row outer raceway surface on the inner periphery and having a flange portion on the outer periphery and fixed to a vehicle member;
A hub flange having one inner raceway surface on the outer periphery and attaching a wheel to the shaft end and an inner ring having the other inner raceway surface on the outer periphery are integrally formed, and a rotatable inner shaft.
A plurality of rolling elements arranged in a freely rollable manner between the outer raceway surfaces and the double row inner raceway surfaces facing each other in the radial direction;
An inner side opening of an annular space formed between the outer ring and the inner shaft has a seal ring integrally formed with a core metal and a lip of an elastic body and fixed to the outer ring, and a shoulder of the inner ring A bearing device for a wheel incorporating a combination seal in combination with a slinger fixed to
The outer ring includes a cylindrical inlay portion that protrudes toward the inner side from the flange portion and is fitted to the vehicle member,
An inner side seal mounting surface is formed by grinding on the outer periphery of the inner part, and the seal ring is externally provided on the inner side seal mounting surface,
In the spigot portion, the wheel bearing device is characterized in that the inner peripheral surface facing the shoulder of the inner ring in the radial direction is not ground.   2. The wheel bearing device according to claim 1, wherein the inner seal mounting surface is a reference surface that abuts a shoe when the outer raceway surface is ground. 3. In the outer ring, a recess formed from the inner side end surface to a predetermined depth is provided inward of the inner portion,
3. The wheel bearing device according to claim 1, wherein the metal core is bent at an inner peripheral end of the inlay portion, and the lip is accommodated in the recess. 4.   The wheel bearing device according to any one of claims 1 to 3, wherein the core metal is made of a non-rusting metal.

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