JP2022144001A - rolling bearing device - Google Patents

Abstract

To provide a rolling bearing device which can secure the sealing performance of a pair of inner-ring abutment parts, and can assure an axial clearance.SOLUTION: A seal member 20 having an outside-diameter side seal part 35 and an inside-diameter side seal part 36 is arranged at an ant groove-shaped seal holding groove 33 having a pair of groove inner faces 33b formed outside an abutment part 32 in a radial direction, the outside-diameter side seal part 35 is arranged outside the seal holding groove 33, and the inside-diameter side seal part 36 is arranged inside the seal holding groove 33. Internal peripheral faces of both-side parts of the outside-diameter side seal part 35 in an axial direction are made to abut on external peripheral faces of a pair of inner rings 18a, 18b, and a pair of inclination outer faces 38 constituting the inside-diameter side seal part 36 are made to abut on a pair of the groove inner faces 33b. A radial-direction clearance 40 is formed between an internal peripheral face of the inside-diameter side seal part 36 and a groove bottom face 33a of the seal holding groove 33.SELECTED DRAWING: Figure 3

Description

The present invention relates to rolling bearing devices.

Rolling bearing devices called hub unit bearings are used to rotatably support automobile wheels. 5 and 6 show an example of a rolling bearing device used to rotatably support and rotationally drive the wheels (driving wheels) of heavy vehicles such as trucks and buses. 1 shows a structure described in Japanese Patent Application Laid-Open Publication No. 2004-200012.

Rolling bearing device 100 rotatably supports hub wheel 102 around axle tube 101 . A drive shaft 103 is inserted through the inside of the axle tube 101 . A flange 104 is provided at the end of the drive shaft 103, and the hub wheel 102 is fixed to the flange 104. As shown in FIG. A driving wheel 105 and a braking rotor 106 are fixed to the hub wheel 102 . With such a configuration, the drive wheels 105 and the braking rotor 106 are rotatably supported with respect to the axle tube 101, and the torque from the drive shaft 103 can be transmitted to the drive wheels 105 and the braking rotor 106. there is

As shown in FIG. 6, the rolling bearing device 100 is a double-row tapered roller bearing comprising an outer ring 107 that rotates in use, a pair of inner rings 108a and 108b that do not rotate in use, and a plurality of rolling elements 109a. , 109 b , a sealing member 110 and a connecting ring 111 .
Regarding the rolling bearing device 100, the axially outer side is the left side in FIG. is the right side of FIG.

The outer ring 107 has double-row outer ring raceways 112a and 112b on its inner peripheral surface. The outer ring 107 is internally fitted to the hub ring 102 with an interference fit.

Each of the pair of inner rings 108a, 108b has a single-row inner ring raceway 113a, 113b on its outer peripheral surface. The pair of inner rings 108a and 108b are fitted onto the axle tube 101 with their opposing small-diameter end surfaces facing each other.

The rolling elements 109a and 109b are tapered rollers, and a plurality of rolling elements are arranged for each row between the outer ring raceways 112a and 112b and the inner ring raceways 113a and 113b so as to be free to roll.

The seal member 110 is composed of an O-ring, and is arranged radially inside a butted portion 114 between the pair of inner rings 108a and 108b. Seal member 110 prevents foreign matter such as differential oil and muddy water present inside axle tube 101 from entering the internal space of rolling bearing device 100 through butted portion 114 .

In the rolling bearing device 100 for rotatably supporting the hub wheel 102 around the axle tube 101, a pair of inner rings 108a and 108b are provided so that the rolling bearing device 100 can be attached to and detached from the axle tube 101. is fitted onto the axle tube 101 with a clearance fit. In addition, since the inner space of axle tube 101 communicates with the inner space of a differential case (not shown), the differential oil is present in the gap between the inner peripheral surfaces of inner rings 108 a and 108 b and the outer peripheral surface of axle tube 101 . intrusion is possible. Moreover, muddy water may flow into the gap between the inner peripheral surfaces of the inner rings 108 a and 108 b and the outer peripheral surface of the axle tube 101 from the outside. Therefore, the seal member 110 is arranged radially inward of the butted portion 114 to prevent foreign matter such as differential oil and muddy water from entering the internal space of the rolling bearing device 100 .

The connecting ring 111 is circular as a whole and has a U-shaped cross section. The connecting ring 111 has a cylindrical connecting portion 115 and a pair of outward flange-shaped locking portions 116 . The connecting ring 111 is provided with a pair of locking portions 116 on the inner peripheral surfaces of the pair of inner rings 108a and 108b, respectively, while the connecting portion 115 covers the seal member 110 from the inner side in the radial direction. It is locked to the locking concave grooves 117a and 117b. Thereby, the connecting ring 111 axially connects the pair of inner rings 108a and 108b. When the rolling bearing device 100 is assembled to the axle tube 101, the friction acting on the inner rings 108a and 108b causes the pair of inner rings 108a and 108b to separate from each other, or the inner ring 108a and the axle tube 101, which are arranged axially outwardly, separate from each other. This prevents the inner ring 108a from slipping out of the axle tube 101 in the axial direction due to collision with the inner ring 108a.

JP 2008-75837 A

The rolling bearing device 100 having the conventional structure described in Japanese Patent Application Laid-Open No. 2008-75837 has room for further improvement in the following aspects.

In the conventional rolling bearing device 100, in order to sufficiently ensure the sealing performance of the abutting portion 114, the sealing member 110 composed of an O-ring is provided between the small-diameter side end surfaces of the pair of inner rings 108a and 108b to some extent. need to be crushed. However, since a certain amount of force is required to crush the seal member 110, before the rolling bearing device 100 is assembled to the vehicle, in a state where the pair of inner rings 108a and 108b are connected by the connection ring 111, the seal member Due to the resilience of 110 , gaps may occur in abutment 114 . For this reason, it becomes difficult to guarantee the axial clearance by conventionally known measuring methods.

Specifically, it is known to measure the axial clearance of a double-row rolling bearing by a method as shown in FIG. First, as shown in FIG. 7A, a pair of inner rings 108x and 108y are abutted against each other on the small-diameter side, and rolling elements 109x and 109y are arranged around the pair of inner rings 108x and 108y. , one inner ring 108x (or 108y) facing downward and the other inner ring 108y (or 108x) facing upward. Then, the axial height from the reference surface 118 to the large-diameter side end surface of the inner ring 108y (or 108x) arranged on the upper side is measured by a displacement meter 119 such as a dial gauge, and the measured value is used as a reference value ( dial to 0).

Next, as shown in FIG. 7B, the rolling elements 109x of one side row and the inner ring 108x are mounted on the outer ring 107x, and the inner ring 108x is placed on the reference surface 118 with the inner ring 108x facing upward. Then, the displacement meter 119 measures the axial height (Hout) from the reference surface 118 to the large-diameter side end surface of the inner ring 108x. Similarly, although illustration is omitted, the inner ring 108y is placed on the reference surface 118 with the inner ring 108y facing upward in a state in which the rolling elements 109y and the inner ring 108y of the other side row are assembled to the outer ring 107x. A displacement meter 119 measures the axial height (Hin) from the reference surface 118 to the large-diameter side end face of the inner ring 108y. Finally, the two axial dimensions (Hin, Hout) are totaled, and the total value [-(Hin+Hout)] is taken as the axial clearance.

In the method for measuring the axial clearance as described above, as shown in FIG. 7A, a pair of inner rings 108x and 108y are arranged above the reference plane 118 in a state in which the small-diameter side end faces of the pair of inner rings 108x and 108y are butted against each other. The axial height to the large-diameter side end surface of the inner ring 108y (or 108x) is used as a reference value. Therefore, if a clearance is generated in the butted portion 114 due to the elasticity of the seal member 110 as in the rolling bearing device 100 having the conventional structure, it becomes difficult to accurately measure the axial clearance, and the axial clearance is guaranteed. become unable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a rolling bearing device that can ensure the sealing performance of the abutted portion between a pair of inner rings and guarantee the axial clearance. intended to

A rolling bearing device according to one aspect of the present invention includes an outer ring, a pair of inner rings, a plurality of rolling elements, a sealing member, and a connecting ring.
The outer ring has a double-row outer ring raceway on its inner peripheral surface.
The pair of inner rings each have a single-row inner ring raceway on the outer peripheral surface.
The rolling elements are arranged between the outer ring raceway and the inner ring raceway.
The seal member seals the abutted portions of the pair of inner rings.
The connecting ring connects the pair of inner rings.
In the rolling bearing device according to one aspect of the present invention, the pair of inner rings includes a pair of groove inner surfaces that are inclined in a direction toward each other in the axial direction toward the radially outer side of the butted portion. It has a dovetail seal retaining groove.
The seal member is made of an elastic material and has an annular shape as a whole, and includes an outer diameter side seal portion arranged outside the seal holding groove, and an outer diameter side seal portion arranged inside the seal holding groove and radially outside the seal holding groove. an inner diameter side seal portion having a cross-sectional shape different from that of the outer diameter side seal portion, the inner diameter side seal portion including a pair of inclined outer surfaces inclined in directions that approach each other in the axial direction toward the outer diameter side seal portion.
The seal member abuts the inner peripheral surfaces on both sides in the axial direction of the outer diameter side seal portion against the outer peripheral surfaces of the pair of inner rings, and contacts the pair of inclined outer surfaces. , and a radial gap is formed between the inner peripheral surface of the inner diameter side seal portion and the bottom surface of the seal holding groove.

In one aspect of the rolling bearing device of the present invention, the inner diameter side seal portion may have a seal concave groove on the inner peripheral surface.

In one aspect of the rolling bearing device of the present invention, the hardness of the seal member can be Hs85 or more and Hs95 or less (Hs90±5).

ADVANTAGE OF THE INVENTION According to this invention, the rolling bearing apparatus which can ensure the sealing performance of the abutment part of a pair of inner rings, and can guarantee the axial gap can be realized.

FIG. 1 is a cross-sectional view showing a driving wheel support device incorporating a rolling bearing device according to a first embodiment. FIG. 2 is a partial cross-sectional view showing the rolling bearing device according to the first embodiment. 3 is a partially enlarged view of FIG. 2. FIG. FIG. 4 is a diagram corresponding to FIG. 3, showing a second example of the embodiment. FIG. 5 is a cross-sectional view showing a drive wheel support device incorporating a conventional rolling bearing device. FIG. 6 is a partial cross-sectional view showing a conventional rolling bearing device. 7(A) and 7(B) are cross-sectional views for explaining a conventionally known axial clearance measuring method in the order of steps.

[First example of embodiment]
A first example of the embodiment will be described with reference to FIGS. 1 to 3. FIG. In this example, the rolling bearing device of the present invention is applied to a driving wheel support device for a heavy heavy vehicle such as a truck or a bus.

[Overall Configuration of Driving Wheel Support Device]
The drive wheel support device 1 includes a rolling bearing device 2, an axle tube 3, a hub wheel 4, and a drive shaft 5, as shown in FIG. The driving wheel support device 1 rotatably supports a driving wheel 6 such as a rear wheel of a truck and a braking rotor 7, and transmits driving torque to the driving wheel 6 and the braking rotor 7. It has a floating configuration.

Regarding the driving wheel support device 1, the axially outer side is the left side in FIG. It is the right side of FIG. 1, which is the center side.

The rolling bearing device 2 rotatably supports the wheel hub 4 around the outer end in the axial direction of the axle tube 3 . The rolling bearing device 2 is arranged between the outer peripheral surface of the axle tube 3 and the inner peripheral surface of the hub wheel 4 .

The axle tube 3 is also called an axle housing, has a cylindrical shape, and has an axially inner end connected to a differential case (not shown). Therefore, the axle tube 3 does not rotate during use. The internal space of the axle tube 3 communicates with the internal space of the differential case. The axle tube 3 has a cylindrical surface portion 8 on the axially outer portion of the outer peripheral surface. Further, the axle tube 3 has a stepped surface 9 facing axially outward at a portion of the outer peripheral surface adjacent to the axially inner side of the cylindrical surface portion 8, and a portion adjacent to the axially outwardly of the cylindrical surface portion 8, It has a male screw portion 10 having a diameter smaller than that of the cylindrical surface portion 8 . A nut 11 for applying preload to the rolling bearing device 2 is screwed onto the male threaded portion 10 .

The drive shaft 5 , also called an axle shaft, is solid and passes through the inside of the axle tube 3 . The drive shaft 5 is arranged coaxially with the axle tube 3 . An axially inner end of the drive shaft 5 is connected to a differential gear (not shown). Therefore, the drive shaft 5 rotates during use. The drive shaft 5 has an outward flange-like flange 12 at its axially outer end projecting from the axle tube 3 . A hub wheel 4 is fixed to the flange 12 with a plurality of bolts 13 .

The hub wheel 4 has an annular shape. The hub wheel 4 has a cylindrical fitting surface 14 on its inner peripheral surface, and a rotary flange 15 on an axially intermediate portion of its outer peripheral surface. A driving wheel 6 is fixed to the rotating flange 15 by a connecting member 16 such as a hub bolt or a stud. A braking rotor 7 is fixed to the inner side of the hub wheel 4 in the axial direction by bolts 13 .

The driving wheel support device 1 rotatably supports the driving wheels 6 and the braking rotating body 7 with respect to the axle tube 3, and transmits torque from the driving shaft 5 to the driving wheels 6 and the braking rotating body. 7 can be transmitted. Further, in the fully floating drive wheel support device 1 , the load of the vehicle is supported not by the drive shaft 5 but by the axle tube 3 . The drive shaft 5 only bears the transmission of torque.

A specific structure of the rolling bearing device 2 of this example will be described below with reference to FIGS. 2 and 3. FIG.
Regarding the rolling bearing device 2, the axially outer side is the left side in FIGS. It is the right side of FIG.2 and FIG.3 which becomes the width direction center side.

<Rolling bearing device>
The rolling bearing device 2 is a back-to-back type double-row tapered roller bearing, and is of a rotating outer ring type. The rolling bearing device 2 includes an outer ring 17 that rotates in use, a pair of inner rings 18a and 18b that do not rotate in use, a plurality of rolling elements 19a and 19b, a seal member 20, and a connecting ring 21. .

《Outer ring》
The outer ring 17 is made of bearing steel, for example, and has an annular shape. The outer ring 17 has a cylindrical surface on its outer peripheral surface, and has outer ring raceways 22a and 22b in a conical concave double-row shape on its inner peripheral surface. The outer ring 17 is internally fitted and fixed to the fitting surface 14 provided on the inner peripheral surface of the hub wheel 4 by an interference fit when the rolling bearing device 2 is assembled to the vehicle. Therefore, the outer ring 17 rotates together with the hub wheel 4 .

《Inner ring》
Each of the pair of inner rings 18a, 18b is made of, for example, bearing steel and has an annular shape. Each of the pair of inner rings 18a, 18b has a conical convex single-row inner ring raceway 23a, 23b in the axially intermediate portion of the outer peripheral surface. Each of the pair of inner rings 18a, 18b has large flanges 24a, 24b and small flanges 25a, 25b on both axial sides of the inner ring raceways 23a, 23b. For this reason, each of the pair of inner rings 18a, 18b has an outer diameter at the large-diameter end provided with the large flanges 24a, 24b larger than the outer diameter at the small-diameter end provided with the small flanges 25a, 25b. is also getting bigger.

Each of the pair of inner rings 18a, 18b has engaging recessed grooves 26a, 26b having a substantially triangular cross-sectional shape on the inner peripheral surface of the small-diameter side end. The locking recessed grooves 26a, 26b are opened only on the inner peripheral surfaces of the inner rings 18a, 18b, respectively, and are provided over the entire circumferences of the inner rings 18a, 18b. The inner peripheral surfaces of the inner rings 18a and 18b have cylindrical small-diameter surface portions 27a and 27b at portions axially deviating from the locking grooves 26a and 26b toward the large-diameter end surfaces. Cylindrical large-diameter surface portions 28a and 28b having an inner diameter larger than that of the small-diameter surface portions 27a and 27b are provided at portions off the locking grooves 26a and 26b toward the small-diameter side end surfaces.

The pair of inner rings 18a and 18b are arranged coaxially with the outer ring 17 radially inward of the outer ring 17 with their small diameter side end surfaces facing each other. The pair of inner ring raceways 23a and 23b are arranged in double rows at positions facing the double row outer ring raceways 22a and 22b in the radial direction.

The pair of inner rings 18a and 18b are loosely fitted to the cylindrical surface portion 8 provided on the outer peripheral surface of the axle tube 3 when the rolling bearing device 2 is assembled to the vehicle. The pair of inner rings 18 a and 18 b are axially sandwiched between a stepped surface 9 provided on the outer peripheral surface of the axle tube 3 and a nut 11 . Thereby, a predetermined preload is applied to the rolling bearing device 2 . For example, the screwing amount (screwing position) of the nut 11 is set so that the internal clearance in the axial direction of the rolling bearing device 2 is zero or a slightly positive or negative value.

In this example, the pair of inner rings 18a and 18b are made of the same member and arranged in opposite directions with respect to the axial direction. For this reason, the pair of inner rings 18a and 18b have the same shape and dimensions, except that they are oriented in the opposite axial direction. However, when carrying out the present invention, it is also possible to use members having different shapes and sizes for each part as a pair of inner rings.

As shown in FIG. 3, of the pair of inner rings 18a and 18b, the inner ring 18a arranged on the outer side in the axial direction has a first abutting surface 29a and a first annular ring on the small diameter end face, which is the inner end face in the axial direction. and grooves 30a.

The first butting surface 29a is a flat surface that exists on a virtual plane perpendicular to the central axis of the inner ring 18a, and is provided on the radially inner half of the axially inner end surface of the inner ring 18a.

The first annular recessed groove 30a is positioned radially outward of the first abutment surface 29a and is provided in the radially outer half of the axially inner end surface of the inner ring 18a. The first annular recessed groove 30a is open to both the outer peripheral surface and the axially inner end surface of the inner ring 18a, and has a substantially trapezoidal cross-sectional shape. In the illustrated example, the radial bottom surface, which is the outer peripheral surface of the first annular groove 30a, is composed of a cylindrical surface and a tapered portion arranged axially inward of the cylindrical surface, the outer diameter of which decreases toward the axially inner side. It is composed of a surface and

The axial bottom surface, which is the axial side surface of the first annular groove 30a, is a conical cylindrical surface that is inclined with respect to an imaginary plane orthogonal to the central axis of the inner ring 18a. Specifically, the axial bottom surface of the first annular recessed groove 30a is inclined inward in the axial direction as it extends radially outward. In the illustrated example, the axial bottom surface of the first annular groove 30a is inclined at about 45° with respect to the central axis of the inner ring 18a. The radial bottom surface and the axial bottom surface of the first annular recessed groove 30a are connected via a corner portion having an arcuate cross section.

The inner ring 18a arranged on the axially outer side has a first annular recessed groove 30a formed therein, so that a first ridge portion 31a having a triangular cross-sectional shape is formed on the radially outer portion of the axially inner end portion. Prepare. The inner peripheral surface of the first ridge portion 31a is composed of the axial bottom surface of the first annular groove 30a.

Of the pair of inner rings 18a and 18b, the inner ring 18b arranged on the inner side in the axial direction has a second butting surface 29b and a second annular recessed groove 30b on the small-diameter side end face, which is the outer end face in the axial direction. .

The second butting surface 29b is a flat surface that exists on a virtual plane perpendicular to the central axis of the inner ring 18b, and is provided on the radially inner half of the axially outer end surface of the inner ring 18b. The outer and inner diameter dimensions of the second butting surface 29b are the same as the outer and inner diameter dimensions of the first butting surface 29a.

The second annular recessed groove 30b is positioned radially outward of the second abutment surface 29b and is provided in the radially outer half of the axially outer end surface of the inner ring 18b. The second annular recessed groove 30b opens to the outer peripheral surface and the axially outer end surface of the inner ring 18b, and has a substantially trapezoidal cross-sectional shape. The radial bottom surface, which is the outer peripheral surface of the second annular groove 30b, is composed of a cylindrical surface and a tapered surface arranged on the axially outer side of the cylindrical surface, the outer diameter of which decreases toward the axially outer side. ing.

The axial bottom surface, which is the axial side surface of the second annular groove 30b, is a conical cylindrical surface that is inclined with respect to a virtual plane perpendicular to the central axis of the inner ring 18b. Specifically, the axial bottom surface of the second annular groove 30b is inclined in the axially outward direction toward the radially outward side. In the illustrated example, the axial bottom surface of the second annular groove 30b is inclined at about 45° with respect to the central axis of the inner ring 18b. The radial depth and axial depth of the second annular groove 30b are the same as the radial depth and axial depth of the first annular groove 30a. The radial bottom surface and the axial bottom surface of the second annular recessed groove 30b are connected via a corner portion having an arcuate cross section. When carrying out the present invention, the radial depth and axial depth of the first annular groove and the radial depth and axial depth of the second annular groove can be made different from each other. Further, the radial bottom surfaces of the first annular groove and the second annular groove may be formed only of cylindrical surfaces or tapered surfaces, or may be formed of surfaces having other generatrix shapes.

A second annular groove 30b is formed in the inner ring 18b arranged on the inner side in the axial direction, so that a second ridge portion 31b having a triangular cross-sectional shape is formed on the radially outer portion of the axially outer end portion. Prepare. The inner peripheral surface of the second ridge portion 31b is composed of the axial bottom surface of the second annular groove 30b.

In the rolling bearing device 2, the first abutting surface 29a of the inner ring 18a arranged axially outside and the second abutting surface 29b of the inner ring 18b arranged axially inward are axially abutted so as to be in surface contact with each other. By doing so, the matching section 32 is configured. Further, in the state where the butted portion 32 is formed, the first annular groove 30a and the second annular groove 30b are connected in the axial direction to form a seal holding groove 33 that opens only radially outward. For this reason, the pair of inner rings 18a, 18b has a seal holding groove 33 extending across the inner rings 18a, 18b in the axial direction.

The seal holding groove 33 is formed in the shape of a dovetail groove having a substantially isosceles trapezoidal cross-sectional shape, and is arranged radially outside the butted portion 32 . The seal holding groove 33 has a groove bottom surface 33a composed of the radial bottom surface of the first annular groove 30a and the radial bottom surface of the second annular groove 30b. The seal holding groove 33 also has a pair of groove inner surfaces 33b, which are composed of the axial bottom surface of the first annular groove 30a and the axial bottom surface of the second annular groove 30b. The pair of groove inner surfaces 33b are inclined toward each other in the axial direction toward the radially outer side.

《Rolling element》
Each of the plurality of rolling elements 19a, 19b is a tapered roller made of bearing steel or ceramic, for example. Each of the plurality of rolling elements 19a, 19b is arranged between the outer ring raceways 22a, 22b and the inner ring raceways 23a, 23b so as to be rollably held by cages 34a, 34b. In addition, each of the rolling elements 19a in the axially outer row has a portion of the axially outer end surface that contacts and faces the large flange portion 24a, and a portion of the axially inner end surface that closely faces the small flange portion 25a. I am letting Each of the rolling elements 19b in the axially inner row has a portion of the axially inner end surface that contacts and faces the large flange portion 24b, and a portion of the axially outer end surface that closely faces the small flange portion 25b. there is

《Seal member》
The seal member 20 is for sealing the butted portion 32 between the pair of inner rings 18a and 18b, and is arranged radially outside the butted portion 32. As shown in FIG.

As shown in FIG. 3, in the rolling bearing device 2 of this embodiment, the cross-sectional contour shape of the seal member 20 is not circular as described in Japanese Patent Laid-Open No. 2008-75837, but is constricted in the radially intermediate portion. It has an approximately eight-character shape.

The seal member 20 is made of an elastic material and is formed in an annular shape as a whole. The seal member 20 is made of acrylonitrile-butadiene rubber (NBR, high-hardness nitrile) having a hardness of Hs 85 or more and Hs 95 or less (HS 90±5) so as to retain its annular shape to some extent before being mounted in the seal holding groove 33 . Made of material. In this example, the hardness of the sealing member 20 is about Hs90.

The seal member 20 includes an outer diameter side seal portion 35 and an inner diameter side seal portion 36 .

The radially outer seal portion 35 constitutes the radially outer half portion of the seal member 20 and has a substantially rectangular cross-sectional shape. The outer diameter side seal portion 35 is arranged outside the seal holding groove 33 with the seal member 20 mounted in the seal holding groove 33 . In other words, the outer diameter side seal portion 35 protrudes radially outward from the seal holding groove 33 .

The axial width of the outer diameter side seal portion 35 is larger than the axial width of the opening of the seal holding groove 33 . In addition, the outer diameter side seal portion 35 has cylindrical inner peripheral surfaces on both sides in the axial direction. In the state where the seal member 20 is mounted in the seal holding groove 33, the outer diameter side seal portion 35 is configured such that the inner peripheral surfaces of both sides in the axial direction are attached to the small flange portions 25a and 25b of the pair of inner rings 18a and 18b, respectively. It is in contact (surface contact) with the outer peripheral surface of the entire circumference. As a result, the radial positioning of the seal member 20 is achieved, and the opening of the seal holding groove 33 is covered over the entire circumference.

In this example, the radial width of the outer seal portion 35 is substantially the same as the radial width of the seal holding groove 33 and the radial width of the inner seal portion 36, and has a certain thickness. This prevents the outer diameter side seal portion 35 from being twisted. The outer diameter side seal portion 35 has chamfered portions on both sides in the axial direction of the outer peripheral surface.

The inner diameter side seal portion 36 constitutes the radially inner half portion of the seal member 20 and has a substantially isosceles trapezoidal cross-sectional shape that is substantially the same as the cross-sectional shape of the seal holding groove 33 . The inner diameter side seal portion 36 is arranged inside the seal holding groove 33 in a state in which the seal member 20 is mounted in the seal holding groove 33 . Specifically, the inner diameter side seal portion 36 is held inside the seal holding groove 33 without looseness.

The inner diameter side seal portion 36 has a cylindrical inner peripheral surface 37 . In addition, the inner diameter side seal portion 36 has a pair of inclined outer surfaces 38 on both sides in the axial direction. Therefore, the axial width of the inner diameter side seal portion 36 becomes smaller toward the radially outer side. The axial width of the portion of the inner diameter side seal portion 36 that has the largest axial width is substantially the same as the axial width of the outer diameter side seal portion 35 . The inclination angle of the inclined outer surface 38 with respect to the central axis of the seal member 20 is slightly smaller than the inclination angle of the groove inner surface 33b with respect to the central axis of the inner rings 18a, 18b. In the illustrated example, the inclined outer surface 38 is inclined about 40° with respect to the central axis of the seal member 20 . Each of the pair of inclined outer surfaces 38 and the inner peripheral surface 37 are not directly connected, but are connected via a chamfered portion.

In the free state of the seal member 20, the axial spacing between the pair of inclined outer surfaces 38 is greater than the axial spacing between the pair of groove inner surfaces 33b when the pair of inner rings 18a and 18b are connected by the connecting ring 21. , at least at a portion of the oblique outer surface 38 is slightly larger. In the illustrated example, the axial spacing between the pair of inclined outer surfaces 38 at the radially inner portion of the inclined outer surfaces 38 is slightly larger than the axial spacing between the pair of groove inner surfaces 33b. The axial interval between the pair of inclined outer surfaces 38 from the radial outer portion to the radial intermediate portion of the inclined outer surface 38 is slightly smaller than the axial interval between the pair of groove inner surfaces 33b.

With the seal member 20 mounted in the seal holding groove 33 , the inner diameter side seal portion 36 has a pair of inclined outer surfaces 38 (in the illustrated example, the radially inner portion) of the inner diameter side seal portion 36 that is aligned with the seal holding groove 33 . It is brought into contact with each of the pair of groove inner surfaces 33b over the entire circumference. In this example, the pair of inclined outer surfaces 38 (the inner diameter side seal portion 36) is slightly displaced in the axial and radial directions while the pair of inclined outer surfaces 38 are in contact with the pair of groove inner surfaces 33b, respectively. elastically deformed.

In the sealing member 20, the cross-sectional shape of the outer diameter side seal portion 35 and the cross-sectional shape of the inner diameter side seal portion 36 are different from each other. As a result, the seal member 20 can be opened in a state in which the seal member 20 is reversed in the radial direction, that is, in a state in which the outer diameter side seal portion 35 is directed radially inward and the inner diameter side seal portion 36 is directed radially outward. cannot be attached to the seal holding groove 33. Specifically, the outer diameter side seal portion 35 is prevented from being arranged inside the seal holding groove 33 .

The seal member 20 has an engagement concave groove 39a having a triangular cross-section in a portion (diameter intermediate portion) between the outer diameter side seal portion 35 and the inner diameter side seal portion 36 in the axial direction side portion. 39b is provided.

In the seal member 20 of this example, in a state in which it is mounted in the seal holding groove 33, the inner peripheral surfaces of both axial side portions of the outer diameter side seal portion 35 are aligned with the small flange portions 25a and 25a of the pair of inner rings 18a and 18b. 25 b in the radial direction (surface contact), and the pair of inclined outer surfaces 38 of the inner diameter side seal portion 36 respectively contact the pair of groove inner surfaces 33 b of the seal holding groove 33 . abut. In other words, when the seal member 20 of this example is mounted in the seal holding groove 33, the first ridge portion 31a and the second ridge portion 31b are aligned with the engagement concave grooves 39a and 39b. Each engages without radial and axial play. As a result, the sealing member 20 is positioned with respect to the pair of inner rings 18a and 18b. That is, the seal member 20 is prevented from moving radially and axially with respect to the pair of inner rings 18a and 18b.

A radial gap 40, which is a minute gap, is formed over the entire circumference between the inner peripheral surface 37 of the inner diameter side seal portion 36 and the groove bottom surface 33a of the seal holding groove 33 in a state in which the seal member 20 is positioned. be done. In this example, since the groove bottom surface 33a is composed of the radial bottom surface of the first annular groove 30a and the radial bottom surface of the second annular groove 30b, each of which has a cylindrical surface and a tapered surface, the radial gap 40 is not constant with respect to the axial direction and is greatest in the central portion in the axial direction.

In this example, with the seal member 20 attached, the inner peripheral surfaces of both sides in the axial direction of the outer diameter side seal portion 35 are brought into contact with the outer peripheral surfaces of the small flange portions 25a and 25b over the entire circumference. Moreover, each of the pair of inclined outer surfaces 38 is brought into contact with each of the pair of groove inner surfaces 33b over the entire circumference. Therefore, according to the rolling bearing device 2 of this embodiment, foreign matter such as differential oil existing inside the axle tube 3 and muddy water from the external space can be removed from the outer peripheral surface of the axle tube 3 and the inner peripheral surfaces of the inner rings 18a and 18b. can be prevented from entering the internal space of the rolling bearing device 2 through the abutting portion 32 after entering the gap between. Therefore, deterioration of the grease sealed inside the rolling bearing device 2 can be prevented.

《Connecting ring》
The connecting ring 21 is for axially connecting the pair of inner rings 18a and 18b, and is made of a metal plate. The connecting ring 21 is annular as a whole and has a substantially U-shaped cross section. The connecting ring 21 has a connecting portion 41 having a cylindrical shape in the middle portion in the axial direction, and a pair of locking portions 42a and 42b each having a substantially L-shaped cross-sectional shape at both ends in the axial direction. have.

The connecting ring 21 is internally fitted in the pair of inner rings 18a and 18b so as to straddle the pair of inner rings 18a and 18b in the axial direction. The connecting ring 21 locks the pair of locking portions 42a and 42b respectively to the locking grooves 26a and 26b provided on the inner peripheral surfaces of the pair of inner rings 18a and 18b. there is Specifically, the outer surface of the locking portion 42a on the axially outer side is brought into contact with the inner surface of the locking groove 26a of the inner ring 18a on the axially outer side without axial play. In addition, the outer surface of the locking portion 42b on the inner side in the axial direction is brought into contact with the inner surface of the locking groove 26b of the inner ring 18b on the inner side in the axial direction without axial play. Thereby, the connecting ring 21 axially connects the pair of inner rings 18a and 18b. Therefore, according to the rolling bearing device 2 of the present embodiment, the friction acting on the inner rings 18a and 18b when the rolling bearing device 2 is assembled to the axle tube 3 causes the pair of inner rings 18a and 18b to separate from each other or to separate in the axial direction. It is possible to prevent the inner ring 18a from slipping out of the axle tube 3 in the axial direction due to collision between the outer ring 18a and the axle tube 3.

The connecting portion 41 has a constant outer diameter and inner diameter along the axial direction, and in the free state of the connecting ring 21, the outer diameter is the same as or slightly larger than the inner diameter of the large diameter surface portions 28a and 28b. have dimensions. Therefore, when the connecting ring 21 is attached (internally fitted) to the pair of inner rings 18a and 18b, the outer peripheral surface of the connecting portion 41 is in contact with the inner peripheral surfaces of the large diameter surface portions 28a and 28b.

《Sealing device》
As shown in FIGS. 1 and 2, the rolling bearing device 2 of this example has openings on both sides in the axial direction of an internal space existing between the inner peripheral surface of the outer ring 17 and the outer peripheral surfaces of the pair of inner rings 18a and 18b. A pair of sealing devices 43a, 43b are further provided to seal the part. One sealing device 43a is arranged between the axially outer portion of the inner peripheral surface of the outer ring 17 and the outer peripheral surface of the large collar portion 24a that constitutes the inner ring 18a arranged axially outside. The other sealing device 43b is arranged between the axially inner portion of the inner peripheral surface of the outer ring 17 and the outer peripheral surface of the large collar portion 24b forming the inner ring 18b arranged axially inward. Such sealing devices 43a and 43b prevent the grease sealed in the internal space of the rolling bearing device 2 from leaking to the external space, and prevent foreign matter such as muddy water existing in the external space from entering the internal space. are preventing.

According to the rolling bearing device 2 of this embodiment as described above, it is possible to ensure the sealing performance of the abutting portion 32 between the pair of inner rings 18a and 18b, and to guarantee the axial clearance.
That is, in this example, in a state in which the seal member 20 is mounted in the seal holding groove 33 provided on the radially outer side of the butted portion 32, the inner peripheral surfaces of both axial side portions of the outer diameter side seal portion 35 are The outer peripheral surfaces of the small flange portions 25a and 25b of the pair of inner rings 18a and 18b are brought into contact with each other, and the pair of inclined outer surfaces 38 of the inner diameter side seal portion 36 are aligned with the pair of seal holding grooves 33. It is brought into contact with each of the groove inner surfaces 33b. Therefore, the seal member 20 can ensure the sealing performance of the butted portion 32 .

Moreover, according to the structure of this example, it is possible to ensure the sealing performance of the butted portion 32 only by slightly elastically deforming each of the pair of inclined outer surfaces 38. Unlike the conventional structure described, it is not necessary to crush the sealing member and elastically deform the sealing member to a large extent in order to ensure the sealability of the abutting portion. Therefore, it is possible to prevent the contact pressure (surface pressure) between the pair of inclined outer surfaces 38 and the pair of groove inner surfaces 33b from increasing. Therefore, according to the structure of this example, the axial elastic force (component of force) acting from the seal member 20 on the pair of inner rings 18a and 18b can be sufficiently reduced. As a result, it is possible to prevent the occurrence of gaps in the butted portion 32 .

Further, in this example, a radial gap 40 is formed between the inner peripheral surface 37 of the inner diameter side seal portion 36 and the groove bottom surface 33 a of the seal holding groove 33 . Therefore, it is possible to prevent a part (diameter direction inner portion) of the seal member 20 from being caught in the abutting portion 32 . In this example, the groove bottom surface 33a of the seal holding groove 33 is composed of the radial bottom surface of the first annular groove 30a and the radial bottom surface of the second annular groove 30b, each of which has a cylindrical surface and a tapered surface. Therefore, a large radial distance (the size of the radial gap 40) from the butted portion 32 to the inner peripheral surface 37 can be ensured. Therefore, it is possible to effectively prevent a portion of the sealing member 20 from being caught between the butted portions 32 .

As a result, according to the rolling bearing device 2 of this embodiment, the pair of inner rings 18a and 18b are connected by the connecting ring 21 to measure the axial clearance by the conventionally known measuring method as shown in FIG. Even in the connected state, it is possible to prevent gaps from forming in the butted portion 32 due to the elasticity of the sealing member 20 or the sealing member 20 being sandwiched between the butted portions 32 . Therefore, the rolling bearing device 2 of this embodiment can accurately measure the reference value of the axial clearance by a conventionally known measuring method. Therefore, it is possible to accurately measure the axial clearance and guarantee the axial clearance. Moreover, this also makes it possible to apply an appropriate preload to the rolling bearing device 2 .

[Second example of embodiment]
A second example of the embodiment will be described with reference to FIG.

A rolling bearing device 2a of this example differs from the structure of the first example of the embodiment only in the structure of a seal member 20a for sealing abutting portion 32 between a pair of inner rings 18a and 18b.

The seal member 20a of this example has an outer diameter side seal portion 35 arranged outside the seal holding groove 33 and an outer diameter side seal portion 35 arranged inside the seal holding groove 33 in a state in which the seal member 20a is mounted in the seal holding groove 33. and an inner diameter side seal portion 36a. The structure of the outer diameter side seal portion 35 is the same as the structure of the outer diameter side seal portion 35 that constitutes the seal member 20 of the first example of the embodiment.

The inner diameter side seal portion 36a has, on both sides in the axial direction, a pair of inclined outer surfaces 38 in the shape of a conical cylinder, which are inclined in directions that approach each other in the axial direction toward the radially outer side. The inner peripheral surface 37a of the inner diameter side seal portion 36a does not have a cylindrical surface shape, and has a seal groove 44 that is recessed radially outward over the entire circumference in an axially intermediate portion. The seal groove 44 has a substantially isosceles trapezoidal cross-sectional shape. Thus, the inner diameter side seal portion 36 a has a pair of fin-shaped (thin-walled) lip portions 45 on both sides of the seal groove 44 in the axial direction. The seal groove 44 is located radially outside the butted portion 32 . Each of the pair of lip portions 45 is positioned axially off the butted portion 32 . When carrying out the present invention, the cross-sectional shape of the seal groove is not limited to a trapezoidal shape, and other shapes such as a triangular shape and a semicircular shape can also be adopted. Moreover, the number of seal grooves formed on the inner peripheral surface of the inner diameter side seal portion is not limited to one, and a plurality of seal grooves may be formed.

In the present example as described above, the seal groove 44 is formed in the axially intermediate portion of the inner peripheral surface 37a of the inner diameter side seal portion 36a, and the fin-shaped lip portions 45 are formed on both sides of the inner diameter side seal portion 36 in the axial direction. is provided, each of the pair of inclined outer surfaces 38 can be easily elastically deformed. Therefore, the contact pressure between the pair of inclined outer surfaces 38 and the pair of groove inner surfaces 33b can be made even lower than in the structure of the first example of the embodiment. Further, since the seal groove 44 is formed on the inner peripheral surface 37a of the inner diameter side seal portion 36a, the radial gap 40a formed between the bottom surface of the seal groove 44 and the groove bottom surface 33a can be increased. Therefore, it is possible to effectively prevent a portion of the seal member 20a from being caught in the butted portion 32. As shown in FIG.
Other configurations and effects are the same as those of the first embodiment.

Although the embodiment of the present invention has been described above, the present invention is not limited to this and can be modified as appropriate without departing from the technical idea of the invention. In addition, the structures of the respective examples of the embodiments can be implemented in combination as appropriate as long as there is no contradiction.

When carrying out the present invention, the respective shapes of the outer diameter side seal portion and the inner diameter side seal portion that constitute the seal member are not limited to the shapes shown in the respective examples of the embodiments, and can be changed as appropriate. . Moreover, when carrying out the present invention, the structure of the connecting ring is not limited to the structure of each example of the embodiment, and can be changed as appropriate. Furthermore, the rolling bearing device of the present invention is not limited to the drive wheel support device, and can be used by being incorporated in the rotation support portion of various mechanical devices.

Reference Signs List 1 drive wheel support device 2, 2a rolling bearing device 3 axle tube 4 hub wheel 5 drive shaft 6 drive wheel 7 braking rotor 8 cylindrical surface portion 9 step surface 10 male screw portion 11 nut 12 flange 13 bolt 14 fitting surface 15 rotating flange 16 Coupling member 17 Outer rings 18a, 18b Inner rings 19a, 19b Rolling elements 20, 20a Sealing members 21, 21a Connecting rings 22a, 22b Outer ring raceways 23a, 23b Inner ring raceways 24a, 24b Large flanges 25a, 25b Small flanges 26a, 26b Engagement Lock grooves 27a, 27b Small diameter surface portions 28a, 28b Large diameter surface portion 29a First abutment surface 29b Second abutment surface 30a First annular groove 30b Second annular groove 31a First ridge portion 31b Second ridge portion 32 Abutment Part 33 Seal holding groove 33a Groove bottom surface 33b Groove inner surface 34a, 34b Cage 35 Outer diameter side seal portion 36, 36a Inner diameter side seal portion 37, 37a Inner peripheral surface 38 Inclined outer surface 39a, 39b Engagement concave groove 40, 40a Radial direction Gap 41 Connecting portion 42a, 42b Locking portion 43a, 43b Sealing device 44 Seal concave groove 100 Rolling bearing device 101 Axle tube 102 Hub wheel 103 Drive shaft 104 Flange 105 Drive wheel 106 Braking rotor 107, 107x Outer ring 108a, 108b, 108x, 108y Inner ring 109a, 109b, 109x, 109y Rolling element 110 Sealing member 111 Connecting ring 112a, 112b Outer ring raceway 113a, 113b Inner ring raceway 114 Matching portion 115 Joint portion 116 Locking portion 117a, 117b Concave locking groove 118 Reference surface 119 Displacement meter

Claims (3)

an outer ring having a double-row outer ring raceway on its inner peripheral surface;
a pair of inner rings each having a single-row inner ring raceway on the outer peripheral surface;
a plurality of rolling elements arranged between the outer ring raceway and the inner ring raceway;
a sealing member that seals the butted portion between the pair of inner rings;
A connecting ring that connects the pair of inner rings,
The pair of inner rings has dovetail-shaped seal holding grooves provided on the radially outer side of the abutting portion and provided with a pair of groove inner surfaces that are inclined in a direction toward each other in the axial direction toward the radially outer side. ,
The seal member is made of an elastic material and has an annular shape as a whole, and includes an outer diameter side seal portion arranged outside the seal holding groove, and an outer diameter side seal portion arranged inside the seal holding groove and radially outside the seal holding groove. an inner diameter side seal portion having a cross-sectional shape different from that of the outer diameter side seal portion, each having a pair of inclined outer surfaces inclined in directions that approach each other in the axial direction toward the
The sealing member abuts the inner peripheral surfaces on both sides in the axial direction of the outer diameter side seal portion against the outer peripheral surfaces of the pair of inner rings, and contacts the pair of inclined outer surfaces. , which are in contact with the pair of groove inner surfaces, respectively, and have a radial gap between the inner peripheral surface of the inner diameter side seal portion and the groove bottom surface of the seal holding groove;
Rolling bearing device. 2. The rolling bearing device according to claim 1, wherein said inner diameter side seal portion has a seal concave groove on its inner peripheral surface. 3. The rolling bearing device according to claim 1, wherein said seal member has a hardness of Hs85 or more and Hs95 or less.

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