JP2001099172A - Drive wheel support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive wheel support device capable of preventing infiltration of muddy water and a leak of differential oil and capable of preventing also infiltration of the differential oil into the inside of a bearing. SOLUTION: An annular stepped part 17 is provided in an inner side end part of an inner ring 10 in a double-row rolling bearing 3 fitted on an external diametric step difference part of an axle pipe 1, a seal ring 18 is mounted in this annular stepped part 17, a clearance between the inner ring 10 and the axle pipe 1 is interrupted from the outside of a drive wheel support device, also by mounting a contact type rubber-made seal 16 in both ends of a bearing part and a seal ring 23 in an annular recessed part 22 provided in a but part external diametric surface respectively, infiltration of muddy water and a leak of differential oil are prevented, so that infiltration of differential oil in the bearing inside can also be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive wheel supporting device for supporting a drive wheel of an automobile by a double row rolling bearing.

[0002]

2. Description of the Related Art Many automobiles, such as trucks, having a frame-structured body adopt a full floating type as an axle structure of drive wheels. Also,
In recent years, unit bearings have been often used in driving wheel support devices for the purpose of improving the assemblability, reducing the size and weight, and the like.

FIG. 4 shows a driving wheel supporting device for a truck as an example. In this drive wheel supporting device, a pair of inner races 53 of a double row tapered roller bearing 52 as a unit bearing is fitted into an outer diameter step portion of an axle tube 51, and is fastened and fixed with a nut 54. The outer ring 55 of the double row tapered roller bearing 52 is fitted on the inner diameter surface of the hub wheel 56, and the axle tube 5
A hub wheel 56 is connected by bolts 59 to a flange 58 of a drive shaft 57 which passes through and is connected to the differential.

[0004] The outer side of the drive wheel supporting device is provided with a drive shaft 5.
7, and the inner side is covered by a seal member 60 mounted between the axle tube 51 and the hub wheel 56,
Dust and water are prevented from entering the support device. A seal member 61 is mounted between the outer axle tube 51 and the drive shaft 57, and a cover 62 is also mounted on the inner side.

[0005]

In the drive wheel supporting apparatus described above, the inner ring of the unit bearing is inserted into the outer diameter step portion of the axle tube so that it can be attached to and detached from the axle tube. There is a slight gap between the inner ring and the axle tube. Also, since the axle tube is in communication with the differential case, muddy water may enter the differential case through this gap,
Differential oil may leak to the outside. Since the unit bearing is formed by dividing the pair of inner rings, there is a possibility that the differential oil may enter into the bearing from the abutting portion of these inner rings.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a drive wheel supporting device which can prevent infiltration of muddy water and leakage of differential oil and also prevent infiltration of differential oil into the inside of a bearing.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is adapted to be fitted to an outer diameter step portion of an axle tube externally fitted to an axle to rotatably support a wheel mounting hub wheel. In a drive wheel supporting device provided with a double row rolling bearing, sealing devices are attached to both ends of a bearing portion of the double row rolling bearing, and a first end portion of a bearing inner ring abutting a shoulder of the axle pipe step portion is provided with a first This adopts a configuration in which a sealing ring is mounted.

That is, by attaching a sealing ring to the end of the inner race of the double row rolling bearing which is inserted into the outer diameter step portion of the axle tube, the sealing ring is mounted on the inner ring and the axle tube. The inside of the drive wheel support device with a slight gap between it and the outside is shielded from outside, preventing infiltration of muddy water and leakage of differential oil, and installing sealing devices at both ends of the bearing part,
This makes it possible to prevent infiltration of differential oil into the bearing.

Regarding the mounting of the first sealing ring,
At the end of the bearing inner ring that abuts the shoulder of the axle tube stepped portion, an annular stepped portion is provided by retreating, a first sealing ring is attached to the retreated annular stepped portion, and this is attached to the shoulder of the axle tube stepped portion. An elastic contact method can be employed.

When the inner race of the double row rolling bearing is formed of a pair of inner races which are abutted in the axial direction, a second sealing ring is straddled and mounted on the outer diameter surface of the abutment portion of the inner race. Thus, it is possible to prevent the differential oil from entering the inside of the bearing from the abutting portion of the inner ring.

Regarding the mounting of the second sealing ring,
A method can be adopted in which an annular concave portion is provided on the outer diameter surface of the butted portion of the pair of inner rings, and the second sealing ring is straddled over the annular concave portion.

A plurality of annular ridges are provided on the inner periphery of the second sealing ring, and at least one annular ridge is formed on the outer diameter surface of each inner ring on both sides of the butted portion of the pair of inner rings.
The airtightness of the inner ring butting portion can be further enhanced by the abutment.

As the double row rolling bearing, an outer ring having a double row rolling surface on the inner periphery, an inner ring having a rolling surface facing each of these rolling surfaces on the outer periphery, and an inner ring facing the inner and outer rings are provided. A double-row tapered roller bearing composed of double-row tapered rollers interposed between the rolling surfaces can be employed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. This drive wheel support device is for a truck, and a drive shaft 2 connected to a differential is passed through an axle tube 1 as shown in FIG.
A hub wheel 4 supported on the outer diameter surface of the axle tube 1 by double row tapered roller bearings 3 is connected to a flange 6 of the drive shaft 2 by bolts 5. A drive wheel 7 is attached to the hub wheel 4 by bolts 8, and a brake rotor 9 is also attached to the inner side of the hub wheel 4 by bolts 5.

The inner ring 10 of the double row tapered roller bearing 3 as the unit bearing is connected to a pair of left and right inner rings by a connecting ring 11 so that an outer diameter step portion of the axle tube 1 has a radial gap of about 20 μm. And is fixedly fastened by a nut 12. The integral outer ring 13 is tightly fitted to the inner diameter surface of the hub wheel 4 with a margin of about 50 μm, and both ends thereof are fixed by the flange 6 and the brake rotor 9.

By mounting the connecting ring 11, when the unit bearing is mounted, the bearing is smoothly inserted into the outer diameter surface of the axle tube 1 without inclining between the inner ring 10 on the inboard side and the inner ring 10 on the outboard side. it can. In addition, even when fretting occurs on the inner race 10 on the inboard side, the inner race 10 on the inboard side, which is to remain on the axle tube 1, can be easily removed, and the bearing can be easily attached and detached.

In the annular space between the inner and outer rings 10 and 13, double row tapered rollers 14 are held by a holder 15,
Contact-type rubber seals 16 are attached to both ends of the annular space in which the grease forming the bearing portion is sealed, and the inside of the bearing is sealed.

The inner and outer rings 10, 13 and the tapered rollers 14
Are manufactured using case hardened steel SCM435, and on their surface, a carbonitrided layer having a carbon content of 0.8% by weight or more and a Rockwell hardness of HRC 58 to 64 is provided with a carbonitrided layer of 1.0 to 1.8.
mm, and the amount of retained austenite in the surface layer from the surface to a depth of 0.4 mm or more is 25 to 35.
% By volume. Also, on the inner diameter surface of each inner ring 10,
A manganese phosphate film is formed as a lubricating film to prevent seizure with the outer diameter surface of the axle tube 1 due to relative sliding with the axle tube 1.

FIG. 2 shows the inner ring 10 at the inner end thereof.
As shown in (a), an annular step 17 is provided to retreat, and a seal ring 18 as a first sealing ring is mounted on the annular step 17. This seal ring 18
Is formed by a cored bar 18a and an elastic member 18b, and the elastic member 18b is brought into contact with the corner radius of the shoulder 19 of the outer diameter step portion of the axle tube 1 so that a slight gap between the inner ring 10 and the axle tube 1 is formed. Is blocked. As a result, it is possible to prevent muddy water from entering through the slight gap and leakage of the differential oil to the outside.

Instead of the seal ring 18, FIG.
As shown in (b) and (c), an O-ring 20 and an X-ring 21 each formed of an elastic member can be attached. These first sealing rings are elastically mounted on the inner race 10 to form a unit, thereby improving the assemblability.

As shown in FIG. 3, an annular recess 22 is provided on the outer diameter surface of the butted portion of the pair of inner rings 10, and a seal ring 23 as a second sealing ring is mounted in the annular recess 22. I have. This seal ring 23 is also formed of a core bar 23a and an elastic member 23b,
Are provided on the inner periphery with two annular ridges 24 straddling and abutting on both sides of the butted portion.

In the above-described embodiment, a double-row tapered roller bearing having a split inner ring is used as the double-row rolling bearing. However, other rolling bearings such as a double-row ball bearing may be used.

[0023]

As described above, according to the drive wheel supporting device of the present invention, the end of the inner race of the double row rolling bearing inserted into the outer diameter step of the axle tube is in contact with the shoulder of the outer diameter step of the axle tube. A sealing ring is attached to the abutting part to block the slight gap between the inner ring and the axle tube from the outside, and sealing devices are installed at both ends of the bearing part, preventing infiltration of muddy water and leakage of differential oil, and In addition, infiltration of the differential oil into the bearing can be prevented.

When the inner race of the double row rolling bearing is formed of a pair of inner races butted in the axial direction, a sealing ring is straddled and mounted on the outer diameter surface of the butted portion of the inner race, so that the butted portion of the inner race is mounted. The differential oil can be prevented from entering the bearing from inside. In addition, the unitization of the bearing can improve the assemblability of the driving wheel support device, and the number of parts can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a driving wheel support device.

2A is an enlarged cross-sectional view showing a sealing ring mounted on an annular step portion of the inner ring of FIG. 1, and FIGS. 2B and 2C are cross-sectional views each showing a modified example of a.

FIG. 3 is an enlarged sectional view showing a sealing ring mounted in an annular concave portion of the inner ring of FIG. 1;

FIG. 4 is a longitudinal sectional view showing a conventional driving wheel support device.

[Explanation of symbols]

 Reference Signs List 1 axle tube 2 drive shaft 3 tapered roller bearing 4 hub wheel 5 bolt 6 flange 7 drive wheel 8 bolt 9 brake rotor 10 inner ring 11 connecting ring 12 nut 13 outer ring 14 tapered roller 15 retainer 16 rubber seal 17 annular step 18 seal Ring 18a Core 18b Elastic member 19 Shoulder 20 O-ring 21 X ring 22 Annular recess 23 Seal ring 23a Core 23b Elastic member 24 Annular ridge

Claims (6)

[Claims] 1. A drive wheel support device comprising a double row rolling bearing which is inserted into an outer diameter step portion of an axle tube which is externally fitted on an axle and rotatably supports a wheel mounting hub wheel.
A sealing device is attached to both ends of the bearing portion of the double row rolling bearing,
A driving wheel support device, wherein a first sealing ring is mounted on an end of a bearing inner ring that abuts a shoulder of the axle tube stepped portion. 2. The axle tube according to claim 1, wherein an annular step portion is provided at an end of the bearing inner ring in contact with a shoulder of the axle tube step portion, and the first sealing ring is attached to the retreated annular step portion. The drive wheel supporting device according to claim 1, wherein the shoulder of the step portion is elastically abutted. 3. An inner ring of the double-row rolling bearing is formed of a pair of inner rings butted in the axial direction, and a second sealing ring is mounted on an outer diameter surface of the butted portion of the inner ring. 3. The driving wheel support device according to 1 or 2. 4. The drive wheel supporting device according to claim 3, wherein an annular concave portion is provided on an outer diameter surface of a butt portion of the pair of inner rings, and the second sealing ring is mounted in the annular concave portion. 5. A plurality of annular ridges are provided on the inner periphery of the second sealing ring, and these annular ridges are provided at least on the outer diameter surface of each inner ring on both sides of the butting portion of the pair of inner rings. The drive wheel support device according to claim 3 or 4, wherein the drive wheel support device is abutted by one. 6. The double-row rolling bearing comprises an outer ring having a double-row rolling surface on an inner periphery, an inner ring having a rolling surface opposed to each of the rolling surfaces on an outer periphery, and opposing the inner and outer rings. The drive wheel supporting device according to any one of claims 1 to 5, comprising a double-row tapered roller bearing comprising a double-row tapered roller interposed between each of the rolling surfaces.