JPH10230752A - Sealing structure of center bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing structure of a center bearing, which is reduced in parts in number, simple in structure, and thereby excellent in assemblage. SOLUTION: In a center bearing supporting structure where an annular supporting member 20 connected with an inner annulus 21 and an outer annulus 22 by way of an elastic member 23, holds a center bearing 3 rotatably supporting a propeller shaft, in the inside of the inner annulus 21, a stopper piece 12 restricting the position of the center bearing 3 with respect to the propeller shaft, is formed out of a cylinder main body part 12a restricting the inner race 3a of the center bearing 3 engaged with the propeller shaft, and of a flange part 12b extended in the centrifugal direction from the cylinder main body part 12a, so that a labyrinth gap 40 is thereby formed up between the flange part 12b and the inner annulus 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure of a center bearing for supporting a propulsion shaft of an automobile.

[0002]

2. Description of the Related Art Usually, a center bearing is supported by an annular support member in which an inner ring and an outer ring are connected via an elastic member, and is fixed at a predetermined position inside the inner ring. In this way, the center bearing that supports the propulsion shaft supports the outer race with the inner ring of the annular support member, but if the front and rear openings of the inner ring are open, muddy water and foreign matter will enter the center bearing. Therefore, they are covered with a dust cover or the like.

FIG. 6 shows an example disclosed in Japanese Utility Model Laid-Open Publication No. Hei 7-2633. The propulsion shaft 01 is the inner race 02 of the center bearing 02 which is a radial ball bearing.
The center bearing 02 is fixedly supported by an annular support member 03 on the outer race 02b.

An annular support member 03 has an inner ring 04 and an outer ring 05 connected by an elastic member 06, and the inner ring 04 has a center bearing 02.
Seal portions 04b, 04b extend in the front-rear direction from the cylindrical portion 04a that is in pressure contact with the outer peripheral surface of the outer race 02b through the throttle steps that contact the front and rear end surfaces of the outer race 02b.

[0005] A labyrinth is formed by combining a dust cover 08 engaged with the outer periphery of an adapter 07 fitted to the propulsion shaft 01 so as to have a U-shaped cross section so as to insert the front seal portion 04b therein. On the other hand, a labyrinth is formed by inserting and combining a rear seal part 04b inside a dust cover 09 also having a U-shaped cross section engaged with the propulsion shaft 01.

The seal structure of the center bearing is disclosed in Japanese Patent Publication No. 4-63259 and Japanese Utility Model Publication No. 7-16510, etc., which are basically the same as the examples described in the above publications.

[0007]

In the above conventional example, the dust cover 08 is attached to the propulsion shaft 01 by the adapter 07.
Separate from the above, the assembly work of both is required, the shape of the dust cover 08 itself is complicated, and the dimensional accuracy is also required,
Poor assembly.

[0008] The present invention has been made in view of such a point,
The object of the present invention is to provide a center bearing seal structure having a simple structure with a small number of parts and excellent in assemblability.

[0009]

In order to achieve the above object, the present invention provides a center bearing in which an annular support member connecting an inner ring and an outer ring via an elastic member supports a propulsion shaft. In the center bearing support structure for holding the center bearing inside the inner ring, a stopper piece that regulates the position of the center bearing with respect to the propulsion shaft is fitted to the propulsion shaft and controls the inner race of the center bearing. A seal structure for a center bearing comprising a main body and a flange extending in a centrifugal direction from the cylindrical main body, and forming a labyrinth gap between the flange and the inner ring.

A stopper piece for regulating the position of the center bearing with respect to the propulsion shaft has a flange portion integrally with the cylindrical main body fitted to the propulsion shaft, and has a labyrinth gap between the stopper ring and the inner ring of the annular support member. Therefore, the gap between the stopper piece and the labyrinth prevents foreign matter and muddy water from entering the center bearing. Since the stopper piece also serves as a dust cover, and the labyrinth gap is formed using the inner ring of the annular support member, the number of parts is small, the structure is simple, and the assembling property is excellent.

According to a second aspect of the present invention, in the center bearing sealing structure according to the first aspect, the stopper piece is formed by integrally forming a cylindrical main body portion and a flange portion by press molding. It is. Therefore, the stopper piece can be easily formed and is inexpensive.

According to a third aspect of the present invention, in the center bearing seal structure according to the first or second aspect, an outer peripheral end surface of a flange portion of the stopper piece faces an inner peripheral surface of an inner ring of the annular support member. The labyrinth gap is formed between the two opposing surfaces. Since the entire stopper piece is housed in the inner ring of the annular support member, the axial width can be minimized, and the seal structure can be made compact.

According to a fourth aspect of the present invention, in the center bearing seal structure according to the first or second aspect, the outer peripheral end of the flange portion of the stopper piece is connected to the open end of the inner ring of the annular support member. The labyrinth gap is formed between both ends by wrapping around the outer peripheral surface side. The distance of the labyrinth gap configured while maintaining a simple structure can be increased, and more reliable sealing performance can be ensured.

According to a fifth aspect of the present invention, in the center bearing seal structure of the first aspect, the labyrinth gap is formed between a flange portion of the stopper piece and one end of the inner ring. The propulsion shaft has an enlarged diameter portion, and forms a labyrinth gap between the enlarged diameter portion and the other end of the inner ring. One end of the inner ring forms a labyrinth gap with the stopper piece and the other end forms a labyrinth gap with the enlarged diameter portion of the propulsion shaft, so that only one stopper piece is sufficient and the assembling work is easy.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment according to the present invention will be described with reference to FIGS. FIG. 1 shows a state in which a center bearing 3 that supports a connecting portion between a first propeller shaft 1 and a second propeller shaft 2 that is a propulsion shaft of an automobile is supported by a center bearing support structure according to the present embodiment. I have.

The first propeller shaft 1 and the second propeller shaft 2 are connected by a connecting member 6. The connecting member 6 includes an inner shaft portion 7, an intermediate shaft portion 8, and a rear cylindrical portion 9 rearward from the front side.
Are formed in order, and are supported by the center bearing 3 at the intermediate shaft portion 8.

The outer end 5a of the tripod universal joint 5 is formed at the rear end of the first propeller shaft 1, and the inner shaft 7 formed on the front side of the connecting member 6 is inserted into the outer 5a, and the inner periphery of the outer 5a is cylindrical. Three tripods 5b radially projecting from the inner shaft portion 7 are slidably fitted into three grooves formed on the surface so as to be oriented in the axial direction, and power is transmitted. The opening of the outer 5a is boots
10 are covered.

The center shaft 3 of the connecting member 6 is supported by the center bearing 3, the front end of the second propeller shaft 2 is connected to the rear cylindrical portion 9 by friction bonding, and the rear end of the second propeller shaft 2 is a universal joint. 15 is connected to the differential.

In such a propulsion shaft, the center bearing 3 which supports the intermediate shaft portion 8 of the connecting member 6 is a radial ball bearing, and the center race 8 is attached to the inner race 3a.
Are inserted and supported. The center bearing 3 has a structure supported by a bracket 25 fixed to the vehicle body via an annular support member 20.

This center bearing support structure will be described with reference to FIGS. 2 and 3. FIG. The bracket 25 is formed by processing a long plate member. Both ends of a semicircular arc portion 25a extend right and left to form mounting flange portions 25b, 25b, and the mounting flange portions 25b, 25b are mounted on the vehicle body side. Arc part 25a
An annular ring member 26 is fixed to the ring. The annular support member 20 is fitted and fixed inside the ring member 26.

The annular support member 20 includes a straight tubular inner ring 21 and an outer ring 22 connected to each other via a rubber 23.
Has an outer diameter and width equal to the inner diameter and width of the ring member 26 of the bracket 25, the inner ring 21 has a larger width than the outer ring 22, and particularly projects greatly rearward, and the inner diameter of the inner ring 21 is the outer diameter of the center bearing 3. It is equal to the outer diameter of the race 3b.

The rubber 23 is bent so that the inner peripheral surface is baked on the front half of the outer peripheral surface of the inner ring 21 and the outer peripheral surface is baked on the inner peripheral surface of the outer ring 22 so that the annular intermediate portion swells forward. ing. The front end of the inner ring 21 extends to a position where it bulges forward in the middle of the rubber 23, so that the front end of the inner ring 21 is accommodated in the rubber 23.

The annular support member 20 is first mounted on the bracket
The outer ring 22 is press-fitted and fixed to the inner peripheral surface of the 25 ring member 26. Thereafter, the center bearing 3 is pressed into the inner ring 21 of the annular support member 20 at a predetermined position. Then, dust seals 30, 30 as annular members are press-fitted from both sides of the inner ring 21.

The dust seal 30 includes a metal seal ring 31.
Has an outer diameter slightly larger than the inner diameter of the inner ring 21.
a and an annular side plate portion 31b bent inward from the end edge thereof, and a rubber seal ripple 32 is fixed to the inner peripheral edge of the annular plate portion 31b. The dust seal 30 is press-fitted into the inner ring 21 with the annular side plate portion 31b of the seal ring 31 facing inward, and the annular side plate portion 31b abuts against the end face of the outer race 3b of the center bearing 3 already press-fitted at a predetermined position. .

The dust seals 30, 30 are press-fitted from both sides of the inner ring 21, and come into contact with both end surfaces of the outer race 3b of the center bearing 3 to sandwich the center bearing 3. Therefore, the center bearing 3 is positioned at a predetermined position on the inner ring 21 of the annular support member 20 and is prevented from falling off.

The intermediate shaft portion 8 of the connecting member 6 of the propulsion shaft is fitted into the center bearing 3 supported by the annular support member 20 as described above, and is pivotally supported as shown in FIG. The diameter of the intermediate shaft portion 8 is increased stepwise from the base diameter portion 8a on which the center bearing 3 is supported, to the first enlarged diameter portion 8b and the second enlarged diameter portion 8b.
The enlarged diameter portion 8c and the third enlarged diameter portion 8d are sequentially formed, and the diameter is further enlarged from the third enlarged diameter portion 8d to form the rear cylindrical portion 9,
The first enlarged diameter portion 8 b is supported by the center bearing 3.

Inner race 3 of center bearing 3
a first enlarged diameter portion 8b of the intermediate shaft 8 is fitted into the rear end face of the inner race 3a.
Positioning is performed by contacting the end faces of c. Then, the third enlarged diameter portion 8 d approaches the inner peripheral surface at the end of the inner ring 21, and the end surface of the rear cylindrical portion 9 approaches the end surface of the inner ring 21, thereby forming a labyrinth gap 40 therebetween.

On the other hand, from the front of the center bearing 3, a stopper piece 12 is fitted into the first enlarged diameter portion 8b of the intermediate shaft 8. The stopper piece 12 has a shape in which one end of a cylindrical main body portion 12a expands in a centrifugal direction and a circular flange portion 12b is integrally formed, and the outer diameter of the flange portion 12b is the inner diameter of the annular support member 20. Slightly smaller than the inside diameter of 21.

The cylindrical body 12a and the flange 12b are integrally formed by press molding. The stopper piece 12 has a cylindrical body with the flange 12b facing forward.
12a is fitted into the first enlarged diameter portion 8b from the front, and the cylindrical main body portion
The rear end face of 12a is brought into contact with the end face of the inner race 3a of the center bearing 3.

Thus, the center bearing 3 is sandwiched by the stopper piece 12 and the second enlarged diameter portion 8c of the intermediate shaft portion 8, and the center bearing 3 pivotally supports the connecting member 6 at a predetermined position. The flange portion 12b of the stopper piece 12 is accommodated in the inner ring 21, and a labyrinth gap 41 is formed between the outer peripheral end surface of the flange portion 12b and the inner peripheral surface of the inner ring 21.

The seal ripple 32 of the dust seal 30 on the front side of the center bearing 3 is in contact with the outer peripheral surface of the cylindrical body 12a of the stopper piece 12, while the seal ripple 32 of the dust seal 30 on the rear side is the second part of the intermediate shaft 8. Large diameter section 8c
And the dust seals 30, 30 on both sides shield the center bearing 3 from the outside. By making the outer diameter of the cylindrical body portion 12a of the stopper piece 12 and the outer diameter of the second enlarged diameter portion 8c of the intermediate shaft portion 8 the same, the left and right dust seals 30, 30 can be shared.

As described above, both sides of the center bearing 3 are covered with the dust seals 30, 30, and the flange portion 12 b of the stopper piece 12 also covers the front as a dust cover. 8d, rear cylindrical part 9
Covers the labyrinth gap 4
Since only 0 and 41 are in communication with the outside, it is possible to almost completely prevent foreign matter, muddy water and the like from entering the center bearing 3.

Since the stopper piece 12 also serves as a dust cover, and the labyrinth gap 41 utilizes the inner ring 21 of the annular support member 20, the number of parts is small, the structure is simple and the assembling property is excellent. The stopper piece 12 has a simple shape, and the cylindrical body portion 12a and the flange portion 12b are integrally formed by press molding to reduce the manufacturing cost.

Since the entire stopper piece 12 is accommodated in the inner ring 21 of the annular support member 20, the width in the axial direction can be minimized, and the sealing structure can be made compact. The connecting member 6 is behind the center bearing 3.
Since the third enlarged diameter portion 8d and the rear cylindrical portion 9 also serve as a dust cover to form the labyrinth gap 40, the stopper piece
12 is enough to constitute the labyrinth gap 41 in front,
Assembly work can also be easily performed.

Next, another embodiment which is a modification of the stopper piece will be described with reference to FIG. All other members except for the stopper piece are the same as those in the above-described embodiment, so the same members are denoted by the same reference numerals.

The stopper piece 50 includes a cylindrical main body portion 51 fitted to the base diameter portion 8a and the first enlarged diameter portion 8b of the intermediate shaft portion 8 of the propulsion shaft connecting member 6, and a base diameter portion of the cylindrical main body portion 51. 8a, a hollow disk-shaped flange portion 52 extending in the centrifugal direction from a portion fitted with 8a, and an outer circumferential edge of the flange portion 52 is bent to form an annular ridge 53 concentric with the cylindrical main body portion 51. .

When the cylindrical main body portion 51 of the stopper piece 50 is fitted to the base diameter portion 8a and the first enlarged diameter portion 8b of the intermediate shaft portion 8,
The flange portion 52 covers the opening of the inner ring 21 of the annular support member 20 from the front, and the ridge 53 covers the outer periphery of the front end of the inner ring 21. That is, in the stopper piece 50, the ridge 53 on the outer peripheral edge of the flange portion 52 wraps around the open end of the inner ring 21 toward the outer peripheral surface side, and the stopper piece 50 projects between the flange portion 52 and the front end surface of the inner ring 21 and projects. Article 53
A labyrinth gap 60 is formed between the inner ring 21 and the outer peripheral surface of the front end.

Although the number of parts is small and the seal structure is simple and compact, the distance of the labyrinth gap 60 can be secured long, the sealing property is improved, and foreign matter and muddy water can more reliably enter the center bearing 3. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a partial plan view partially showing a support state of a propulsion shaft according to an embodiment of the present invention.

FIG. 2 is a front view showing a seal structure of a center bearing.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is an enlarged sectional view of a main part of FIG.

FIG. 5 is a cross-sectional view of a main part showing a seal structure of a center bearing according to another embodiment.

FIG. 6 is a partially sectional side view showing a conventional center bearing support structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st propeller shaft, 2 ... 2nd propeller shaft, 3 ... Center bearing, 5 ... Tripod universal joint, 6 ... Connecting member, 7 ... Inner shaft part, 8 ... Intermediate shaft part,
9: Rear cylindrical part, 10: Boots, 12: Stopper piece,
15 ... universal joint, 20 ... annular support member, 21 ... inner ring, 22 ... outer ring, 23 ... rubber, 25 ... bracket, 26 ... ring member, 30
... dust seal, 31 ... seal ring, 32 ... seal ripple. 40, 41… Labyrinth gap, 50… Stopper piece, 5
1 ... cylindrical body, 52 ... flange, 53 ... ridge, 60 ... labyrinth gap.

Claims (5)

[Claims] 1. A center bearing support structure in which an annular support member connecting an inner ring and an outer ring via an elastic member holds a center bearing that supports a propulsion shaft inside the inner ring. In contrast, a stopper piece that regulates the position of the center bearing includes a cylindrical body that fits into the propulsion shaft and regulates an inner race of the center bearing, and a flange that extends in a centrifugal direction from the cylindrical body. Wherein a labyrinth gap is formed between the flange portion and the inner ring. 2. The center bearing sealing structure according to claim 1, wherein said stopper piece is formed by press-forming a cylindrical main body portion and a flange portion. 3. The labyrinth gap between the outer peripheral end surface of the flange portion of the stopper piece and the inner peripheral surface of the inner ring of the annular support member. The center bearing support structure according to claim 1 or 2. 4. The labyrinth gap is formed between both ends by an outer peripheral end of a flange portion of the stopper piece wrapping around an open end of an inner ring of the annular support member toward an outer peripheral surface side. The center bearing support structure according to claim 1 or 2, wherein 5. The labyrinth gap is defined between a flange portion of the stopper piece and one end of the inner ring, wherein the propulsion shaft has an enlarged diameter portion, wherein the enlarged diameter portion and the inner ring are provided. 2. A seal structure for a center bearing according to claim 1, wherein a labyrinth gap is formed between said labyrinth and said other end.