JPH08284972A - Sealing device for universal joint - Google Patents

Abstract

PURPOSE: To prevent a boot from being damaged between a drive shaft and an adapter when the axis of the drive shaft is bent in a sealing device, and to prevent the boot from being damaged by being abutted on the adapter even when the boot is abnormally deformed. CONSTITUTION: A sealing device is provided with an adapter 15 having a connection part 12, and a boot 30 made of rubber-like elastic material having an adhered part one end of which is adhered to the connection part 12, and a buffer part 17 projected from a free end of the connection part 12 is provided on the adhered part 16. The adapter 15 having the connection part 12 and the boot 30 made of rubber-like elastic material having the adhered part 16 one end of which is adhered to the connection part 12 are provided, the adhered part 16 of the boot 30 is formed longer than the distance from the adhered part 16 of an intermediate flexible part 18 to the turning point, and formed to be thicker in wall thickness toward the turning point side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boot sealing device with an adapter for a universal joint. In particular, the present invention relates to a sealing device in which the joint between the adapter and the boot is improved to improve durability and pressure resistance.

[0002]

2. Description of the Related Art As a prior art relating to a universal joint sealing device of the present invention, there is Japanese Utility Model Laid-Open No. 2-56919.
This publication discloses the sealing device shown in FIG. FIG. 6 is a half sectional view of a sealing device for a universal joint. In FIG. 6, reference numeral 51 is a propeller shaft. The propeller shaft 51 is connected to the companion flange 5 via a joint 52.
3 are connected.

A spline is formed on a stub shaft 51A which is an end portion of the propeller shaft 51, and an inner race 52A of a joint 52 is fitted to the stub shaft 51A via the spline. Also,
A ball 54 held by a ball cage 55 is mounted in the opposing grooves of the outer race 52B of the joint 52 connected to the companion flange 53 and the inner race 52A of the joint 52 connected to the propeller shaft 51. . The outer race 52B, the companion flange 53, and the adapter 59 are fastened together by bolts 61.

One end of an adapter 59 attached to the joint 52 is connected to one end of a rubber boot 60 having a U-shaped cross section. The other end on the inside is fixed to the stub shaft 51A by a band 57. The boot 60 and the adapter 59 seal the joint 52 on the side of the propeller shaft 51, and seal the grease in the joint 52. Further, the cushioning member 58 is the adapter 5 of the boot 60.
It is provided along the inner peripheral side of the portion held by 9. The material is made of an elastic material such as rubber and is fixed to the above-mentioned position with an adhesive or the like.

Therefore, in the joint structure having such a structure, the inner race 52A and the outer race 52B are formed.
By keeping the balls 54 rotatably gripping each other, even if there is a bend between the shafts at the joint 52, they are rotated integrally at a constant rotation speed and power is transmitted.

Further, in connection with the boot 60, the cushioning member 5
By providing 8, it is possible to prevent the connecting portion 63 between the boot 60 and the adapter 59 from coming into contact with the portion of the boot 60 attached to the propeller shaft 51 even when extreme bending occurs between the shafts. The cushioning member 58 serves to cushion the flexible portion 56 of the boot 60 from damage.

However, since one end of the boot 60 is connected, the attachment portion thickened is connected so that one end of the adapter 59 surrounds it, so that it becomes thicker and the cushioning member 58 is attached to the inner peripheral side. It becomes thicker. Therefore,
When the propeller shaft 51 bends its axis through the ball 54, it comes into contact with the buffer member 58, so that the refraction angle of the propeller shaft 51 cannot be increased.

Further, as still another prior art relating to the universal joint sealing device of the present invention, there is Japanese Utility Model Laid-Open No. 3-69320. FIG. 7 is a sectional view of the sealing device for the universal joint. 7, the relationship between the joint 52 and the propeller shaft 51 is substantially the same as that of the universal joint shown in FIG.

Adapter 5 with one end attached to joint 52
The other end of 9 is connected to one end of the boot 60. The boot 60 has a U-shaped cross section, and the other end of the boot 60 is attached to the propeller shaft 51. The coupling side of the boot 60 coupled to the adapter 59 is the adapter 5
A certain width is in contact with the intervening portion 62 having a triangular cross-section that is adhered to 9. In this structure, in a normal operating state, the boot 60 is in contact with the interposition part 62, but if pressure is generated inside or abnormal rotation occurs, the pressure between the interposition part 62 and the boot 60 is rather increased. Or the action of external force makes it easier for the flexible portion 56 to flip outward. When this reversal occurs, the flexible portion 56 contacts the adapter 59, and the boot 60 is damaged.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior art as described above, and its purpose is to prevent the boot from coming into contact with the connecting portion of the adapter and being damaged. In addition, the pressure in the boot prevents the intermediate flexible portion of the boot from being flipped axially outward, and the flipped portion is prevented from being crimped between the drive shaft and the coupling portion of the adapter and being damaged. .

[0011]

The present invention has been made to solve the above-mentioned problems, and its technical means is configured as follows. That is, claim 1
A sealing device for a universal joint, which covers a sliding side where a joint and a shaft are connected to each other, is a tubular adapter having a mounting portion which is connected to the joint on one end side and a connecting portion on the other end side, and Fitting in which one end side is bonded to the coupling part of the adapter and also an intermediate flexible part is projected from the adhesive part and folded back into the adapter, and the other end side of the intermediate flexible part is fitted to the shaft. Equipped with a rubber-like elastic material boot having a portion,
The adhesive portion has a buffer portion protruding from the free end of the connecting portion. Claim 2 is a sealing device for a universal joint, which covers the sliding side where the joint and the shaft are connected. A cylindrical adapter having a mounting part for coupling with a joint and a connecting part on the other end side, and an adhesive part with one end side adhered to the connecting part of the adapter, and an intermediate part projecting from the adhesive part into the adapter and folded back A boot made of a rubber-like elastic material having a flexible portion, and the other end side of the intermediate flexible portion having a fitting portion fitted to the shaft is provided, and the adhesive portion of the boot is folded back from the adhesive portion of the intermediate flexible portion. The length is longer than the length up to and the thickness is increased toward the folding side.

[0012]

According to the sealing device for a universal joint of the present invention, when the shaft is bent and rotated through the balls of the joint and the angle of the shaft becomes large, the intermediate flexible portion comes into contact with the free end of the adapter.
Since a cushioning portion made of a rubber-like elastic material projects from the free end, the cushioning portion protects from damage. or,
Since the free end of the adapter and the boot are bonded by adhesion, the free end of the adapter becomes thin and can be easily processed into a tapered shape. Therefore, the free end of the adapter can be tapered so as not to abut the intermediate flexible portion.

Furthermore, since the adhesive portion of the boot is formed longer than the length from the adhesive portion of the intermediate flexible portion to the folded back portion, even if the intermediate flexible portion expands outward, the intermediate flexible portion will have the adapter. Does not expand until it abuts the free end of the. or,
Since the intermediate flexible portion is held by the thick elastic adhesive portion, an unreasonable force does not act on the adhesive portion side of the intermediate flexible portion.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a sealing device for a universal joint according to the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a sealing device for a universal joint according to an embodiment of the present invention. In FIG. 1, 1 is an outer ring. The outer ring 1 is provided with a bolt hole 4 so as to be connected to a flange (not shown) via a bolt.
An inner groove 5 is provided on the inner circumference of the outer ring 1, and a ball 2 is slidably engaged with the inner groove 5. An inner ring 3 provided with an outer groove 6 for engaging the ball 2 on the inner peripheral side of the ball 2.
Is fitted on the drive shaft 8. The inner ring 3 and the drive shaft 8 are engaged with each other at the spline portion. In addition, the ball 2 is a retainer 9
It is placed in the hole and is held so as not to move.

In the universal joint 10 thus constructed, the outer ring 1 side and the drive shaft 8 can be rotated by bending the shaft center via the ball 2. Therefore, the sealing device must seal the ball 2 side of the universal joint 10 and be elastically deformable to correspond to the displacement angle.

The sealing device 40 has an attaching portion 11 on one side which is fitted to the outer ring 1 as a whole, and an adapter 15 having a connecting portion 12 on the other side, and the connecting portion 12 of the adapter 15.
The boot 30 has an adhesive portion 16 for adhering to the one end and the other end fitted to the drive shaft 8.

The adapter 15 is made of a metal plate and has a stepped mounting portion 11 which is fitted to one end of the outer race 1. The mounting portion 11 has a mounting hole 1 corresponding to the same position as the bolt hole 4.
4 are provided. Then, it is formed in a tubular shape from the mounting portion 11 and has a connecting portion 12 on the free end side.

The adapter 15 includes an iron plate, a stainless plate,
It can be formed from a copper plate or the like. Also, a resin material can be used if necessary.

The boot 30 includes the connecting portion 12 of the adapter 15.
It has the adhesion part 16 adhered to. The adhesive portion 16 covers the free end of the connecting portion 12 and protrudes to form a buffer portion 17. The buffer portion 17 may have a lip shape that is inclined inward. The intermediate flexible portion 18 side of the adhesive portion 16 is formed thick so that the intermediate flexible portion 18 is prevented from being reversed (abnormally deformed). Furthermore, the adhesive portion 1
The outer peripheral portion 19 of 6 adheres to the outer peripheral surface of the connecting portion 12 to firmly hold the adhesive portion 16. This adhesion is performed by vulcanization adhesion or adhesive at the time of molding.

Furthermore, the boot 30 is formed in a taper shape from the adhesive portion 16 toward the inner peripheral side of the adapter 15, and is folded back to project outwardly in a taper shape to be close to the drive shaft 8. It has a section 18. The intermediate flexible portion 18 is
There are various types such as one having substantially the same thickness, or one having a thickness that increases toward both ends.

Further, at one end of the intermediate flexible portion 18 which is close to the drive shaft 8, there is a fitting portion 20 which is fitted to the drive shaft 8. An attachment groove 21 is formed on the outer periphery of the fitting portion 20, and a band 22 is attached to the attachment groove 21 to fasten the fitting portion 20 to the drive shaft 8.

Further, the vent hole 2 is formed in the inner peripheral surface of the fitting portion 20.
3 is formed between itself and the drive shaft 8. Also, the fitting portion 20
A thin film portion 24 that fits with the drive shaft 8 is provided outside. The film portion 24 is expanded by the pressure that has passed through the ventilation hole 23 when the internal pressure in the boot 30 rises, and forms a gap with the drive shaft 8.

The material of the boot 30 is selected as required, such as a rubber material or a resin material.

FIG. 2 is a half sectional view of a sealing device for a universal joint according to another embodiment of the present invention.

2 is different from the sealing device shown in FIG. 1 in that a connecting hole 25 penetrating inward and outward is provided in the connecting portion 12 of the adapter 15, and the adhesive portion 16 passes through the outer peripheral portion 19 and the inside of the connecting hole 25. The point is that they are integrally formed.
Further, the inside of the connecting portion 12 of the adhesive portion 16 is formed in a substantially triangular cross section toward the intermediate flexible portion 18 side. Other configurations are similar to the sealing device of FIG. The material is
Made of resin material.

FIG. 3 is a half sectional view of a sealing device for a universal joint according to still another embodiment of the present invention. 3 is different from the sealing device of FIG. 1 in that the adapter 15 is made of a resin material. This structure is for strengthening the adhesion between the adapter 15 and the boot 30. Moreover, even if the intermediate flexible portion 18 contacts the cushioning portion 17, the cushioning effect is exerted.

FIG. 4 is a half sectional view of a sealing device according to still another embodiment. 4 is different from FIG. 1 in that the connecting portion 12 of the adapter 15 is tapered outwardly. The adapter 15 is made of a metal material. The boot 30 is made of rubber.

In this adapter 15, the diameter can be increased in a taper shape from the mounting portion 11 to the free end instead of from the connecting portion 12. The refraction angle θ of the drive shaft 8 can be increased by enlarging the taper shape.

FIG. 5 is a half sectional view of a sealing device according to still another embodiment. 5 is different from the sealing device of FIG. 1 in that a part of the inner peripheral side of the adhesive portion 16 is not adhered with a certain width and is in a non-adhesive A state, and is formed on the lip portion 28. Is. The connecting hole 25 is provided in the connecting portion 12, and a part of the connecting hole 25 is not filled with the adhesive portion 16 and is formed in the communication hole 29.

The lip portion 28 is normally joined to the connecting portion 12 side, but when the pressure inside the boot 30 rises and the intermediate flexible portion 18 tries to expand outward, the intermediate flexible portion 1 is formed.
The pulling force of 8 separates the lip portion 28 from the connecting portion 12. Therefore, the pressure inside the boot 30 can be released to the outside through the communication hole 29.

As a result, the pressure in the boot 30 drops, and the expansion of the intermediate flexible portion 18 is prevented. Further, since the intermediate flexible portion 18 does not expand, it is possible to prevent the intermediate flexible portion 18 from coming into contact with the free end side of the adapter 15 and being damaged.

[0033]

According to the first aspect of the present invention, in the sealing device for a universal joint of the present invention, since the buffer portion is provided on the free end side of the connecting portion of the adapter, the drive shaft has a refraction angle θ via a ball.
It is possible to effectively prevent the intermediate flexible portion of the boot from being damaged even if the maximum contact angle is brought into contact with the free end of the adapter. Further, since the connecting portion of the adapter is adhered to the adhesive portion of the boot, the connecting portion does not become thick in the radial direction as in the conventional example, and the contact with the intermediate flexible portion can be reduced. Can be expected. At the same time, the refraction angle θ of the drive shaft can be increased correspondingly, and as a result, the size of the entire universal joint can be reduced. Further, the adhesive structure of the connecting portion of the adapter and the adhesive portion of the boot allows the free end side, which is the connecting portion side of the adapter, to be bent freely in a taper shape, so that it can be brought into contact with the intermediate flexible portion of the boot. It is possible to form a shape that can prevent contact.

According to the second aspect of the present invention, since the length of the adhesive portion is formed to be larger than the length of the intermediate flexible portion from the adhesive portion to the folded back portion, even if the intermediate flexible portion expands outward, The expansion part of the intermediate flexible part is not damaged by the adapter. Further, since the adhesive portion of the boot is formed longer than the adhesive portion side of the intermediate flexible portion and is formed thicker toward the intermediate flexible portion side, the intermediate flexible portion is elastic. It is expected that the intermediate flexible portion will be effectively prevented from expanding outward at the same time.

[Brief description of drawings]

FIG. 1 is a sectional view of a sealing device for a universal joint according to an embodiment of the present invention.

FIG. 2 is a half sectional view of a sealing device for a universal joint according to another embodiment of the present invention.

FIG. 3 is a half sectional view of a universal joint sealing device according to still another embodiment of the present invention.

FIG. 4 is a half sectional view of a sealing device according to still another embodiment of the present invention.

FIG. 5 is a half sectional view of a sealing device for a universal joint according to still another embodiment of the present invention.

FIG. 6 is a cross-sectional view of a conventional universal joint sealing device.

FIG. 7 is a cross-sectional view of a conventional constant velocity joint sealing device.

[Explanation of symbols]

 1 …… Outer ring 2,54 …… Ball 3,7 …… Inner ring 4 …… Bolt hole 5 …… Inner groove 6 …… Outer groove 8 …… Drive shaft 9 …… Cage 10 …… Universal joint 11 …… Mounting Part 12 ...... Connection part 13 ...... Spline part 14 ...... Mounting hole 15, 59 ...... Adapter 16 ...... Adhesive part 17 ...... Buffer part 18 ...... Intermediate flexible part 19 ...... Outer peripheral part 20 ...... Fitting part 21 ... Mounting groove 22,57 ... Band 23 ... Vent hole 24 ... Membrane part 25 ... Connection hole 26 ... Folding part 28 ... Lip part 29 ... Communication hole 30,60 ... Boots 40 ... Sealing device 50 ... Sealing device (sealing device) 51 ... Propeller shaft 51A ... Stub shaft 52 ... Joint 52A ... Inner race 52B ... Outer race 53 ... Companion flange 55 ... Ball cage 56 ... Flexible part 58 ... loose Member 61 ...... bolts 62 ...... interposed section 63 ...... connecting portion

Claims (2)

[Claims] 1. A sealing device for a universal joint, which covers a sliding side where a joint (1) and a shaft (8) are connected to each other, and a mounting portion (11) which is connected to the joint (1) at one end side. A cylindrical adapter (15) having a connecting part (12) on the other end side, and an adhesive part (16) having one end adhered to the connecting part (12) of the adapter (15) and the adhesive part Fitting that has an intermediate flexible portion (18) projecting from (16) into the adapter (15) and folded back, and the other end side of the intermediate flexible portion (18) is fitted to the shaft (8). A boot (30) made of a rubber-like elastic material having a wearing part (20) is provided, and the adhesive part (16) has a buffer part (17) protruding from a free end of the connecting part (12). Sealing device for universal joints. 2. A sealing device for a universal joint, which covers a sliding side where the joint (1) and a shaft (8) are connected to each other, and a mounting portion (11) which is connected to the joint (1) at one end side. A cylindrical adapter (15) having a connecting part (12) on the other end side, and an adhesive part (16) having one end adhered to the connecting part (12) of the adapter (15) and the adhesive part Fitting that has an intermediate flexible portion (18) projecting from (16) into the adapter (15) and folded back, and the other end side of the intermediate flexible portion (18) is fitted to the shaft (8). A boot (30) made of a rubber-like elastic material having a wearing part (20) is provided, and the adhesive part (16) of the boot (30) is from the adhesive part (16) of the intermediate flexible part (18) to the folding back. Is formed longer than the length of the Sealing device for universal joints.