JPH09210080A - Boot for joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent excessive deformation of the shape of a boot for joint when it rotates. SOLUTION: A boot for joint 22 is provided with a bellow part 42, a small diameter mounting part 44 which is fitted in an outer peripheral part of a follow-up shaft 18, a large diameter mounting part 46 which is fitted in an outer peripheral part of an outer cup 16, and a plurality of tongue pieces 56 which are divided and formed through a plurality of slits 54 which surround the outer peripheral face of the follow-up shaft 18 and are extended along the direction of axial line and are provided in such a manner that they can come into contact with an inner wall face 58 of the bellow part 42 by expanding one end part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint boot having one end fitted to an outer member constituting a joint and the other end fitted to a shaft of a drive shaft or a driven shaft.

[0002]

2. Description of the Related Art For example, in a vehicle such as an automobile, in order to transmit power (rotational driving force) from a drive shaft to a driven shaft,
A constant velocity joint as a joint is generally used. A bellows-shaped boot is attached to this constant velocity joint in order to ensure liquid tightness inside.

Specifically, one end of the boot is fitted so as to close an opening of a housing (outer cup) which constitutes a constant velocity joint, and the other end of the boot surrounds an outer peripheral portion of a driven side shaft. It is fitted to do.

[0004]

By the way, when the rotational driving force is transmitted from the drive shaft to the driven shaft side, the boot integrally rotates under the rotating action of the constant velocity joint. At that time, the boot is inflated by the centrifugal force generated by the rotation, or the drive shaft or the driven shaft is inclined by a predetermined angle, and the drive shaft and the driven shaft rotate in an eccentric state not on the same axis. The shape of the boot is excessively deformed. Due to such excessive deformation of the boot, the rotational balance of the boot itself is deteriorated and the efficiency of transmission of the rotational driving force transmitted from the drive shaft to the driven shaft is reduced.

The present invention has been made in order to overcome the above-mentioned inconvenience, and prevents the shape of the joint from excessively deforming with the rotation of the joint boot, and maintains a predetermined shape even at high speed rotation. An object of the present invention is to provide a boot for joints that can be made.

[0006]

In order to achieve the above object, the present invention has a shaft, one end of which is fitted to an outer peripheral portion of an outer member forming a joint, and the other end of which is a drive shaft or a driven shaft. A boot for a joint fitted to the outer peripheral part of the bellows part formed in a bellows shape, a small-diameter mounting part formed at one end of the bellows part and fitted to the outer peripheral part of the shaft, Via a large-diameter mounting portion formed at the other end of the bellows portion and fitted to the outer peripheral portion of the outer member, and a plurality of slits that surround the outer peripheral surface of the shaft and extend along the axial direction. A plurality of tongue pieces that are formed in a divided manner and are provided so as to be in contact with the inner wall surface of the bellows portion by expanding the diameter of one end portion.

In this case, the plurality of tongue pieces are integrally connected to the small-diameter attachment portion, and the small-diameter attachment portion, the bellows portion and the large-diameter attachment portion including the plurality of tongue pieces are integrally formed, or the plurality of tongue pieces are formed. It is preferable that the tongue piece is formed separately from the small-diameter mounting portion, the bellows portion, and the large-diameter mounting portion, and the plurality of tongue pieces are held on the outer peripheral portion of the shaft separated from the small-diameter mounting portion by a predetermined distance via a tightening member. .

According to the present invention, when the rotational driving force is transmitted from the drive shaft to the driven shaft in a state where one of the drive shaft and the driven shaft is inclined by a predetermined angle, one end of the tongue piece is moved under the action of centrifugal force. The diameter gradually increases, and finally one end of the tongue comes into contact with the inner wall surface of the bellows portion. As a result, deviation of the bellows portion is prevented, and excessive deformation of the shape of the joint boot can be prevented.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, preferred embodiments of a joint boot according to the present invention will be given and described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a constant velocity joint in which a joint boot 22 according to the first embodiment of the present invention is assembled.

The constant velocity joint 10 has a cylindrical outer cup 16 integrally connected to one end of the drive shaft 12 and having an opening 14, and a fixed outer end of the driven shaft 18 in the hole of the outer cup 16. Inner member 20 stored in
And a joint boot 22 having one end fitted to the outer peripheral portion of the outer cup 16 and the other end fitted to the outer peripheral portion of the driven shaft 18.

On the inner peripheral surface of the outer cup 16, three track grooves extending along the axial direction are formed at intervals of 120 degrees around the axis, and each track groove is an outer side. It has a roller guide groove 26 in which the roller 24 rolls.

A spider 28 is fitted on the driven shaft 18,
On the outer peripheral surface of the spider 28, swelling toward the track groove is provided at intervals of 120 degrees around the axis.
Book spider shafts 30a to 30c are fixed. A ring-shaped inner roller 32 is externally fitted to each of the spider shafts 30a (30b, 30c), and a holder 34 is externally fitted to the inner roller 32.

The outer roller 24 is fitted onto the outer peripheral portion of the holder 34 via a plurality of needle bearings 36. The needle bearing 36 is held by a guide washer 38 attached to the holder 34, and the guide washer 38 is locked by a circlip 40 fitted in an annular groove of the holder 34.

The joint boot 22 according to the first embodiment.
Has a bellows portion 42 formed in a bellows shape of a predetermined length, a small diameter mounting portion 44 is formed at one end of the bellows portion 42, and a large diameter mounting portion 46 is formed at the other end of the bellows portion 42. Is formed. The small-diameter mounting portion 44 is fitted in a first annular groove 48 formed in the outer peripheral surface of the driven shaft 18, and the large-diameter mounting portion 46 is in a second annular groove 50 formed in the outer peripheral surface of the outer cup 16. Be fitted. The small-diameter mounting portion 44 and the large-diameter mounting portion 4 are attached to the bellows portion 42 formed thinly.
6 is formed to be slightly thick.

The small-diameter mounting portion 44 is integrally formed with a cylindrical portion 52 projecting toward the large-diameter mounting portion 46, and the cylindrical portion 52 has a predetermined length from one end thereof along the axial direction. A plurality of slits 54 are formed so as to extend around the axis and are spaced at a predetermined angle. The cylindrical portion 52 is divided into a plurality of tongue pieces 56 by a plurality of slits 54, and one end portion of the tongue piece 56 is expanded in the direction of arrow A so that the bellows portion 4 is formed.
It is formed so as to be able to contact the inner wall surface 58 of the second. A predetermined amount of lubricating grease (not shown) is sealed in the space 60 that is liquid-tightly closed by the joint boot 22. In addition, it is preferable that the entire boot 22 for joints including the bellows portion 42, the small diameter mounting portion 44, the large diameter mounting portion 46, and the cylindrical portion 52 is integrally formed of a rubber material.

The constant velocity joint 10 to which the joint boot 22 according to the first embodiment of the present invention is assembled is basically constructed as described above. Will be described.

First, the case where the constant velocity joint 10 is assembled so that the axis C of the driven shaft 18 is inclined at a predetermined angle with respect to the axis B of the drive shaft 12 in a normal state will be described below as an example. At that time, the axis B of the drive shaft 12 and the driven shaft 1
Since the axis C of 8 is not on the same axis, the joint boot 2
The center of gravity O of 2 and the axis C of the driven shaft 18 are separated by a distance L (see FIG. 3). Even when the constant velocity joint 10 is assembled so that the drive shaft 12 and the driven shaft 18 are coaxial with each other, the center of gravity of the joint boot 22 is caused by the inclination of the driven shaft 18 with respect to the drive shaft 12 by a predetermined angle. The O and the axis C of the driven shaft 18 are separated by the distance L.

In such a state, when the drive shaft 12 rotates in a predetermined direction, the rotational driving force is generated by the outer cup 1.
6 is transmitted to the inner member 20 through the spider shaft 30.
The driven shaft 18 rotates in a predetermined direction via a to 30c, and the rotational driving force is transmitted from the drive shaft 12 to the driven shaft 18 side.

The rotational driving force is transmitted from the drive shaft 12 to the driven shaft 1
8 is transmitted to the outer cup 16 and the driven shaft 18
The joint boot 22 rotates in a predetermined direction integrally with. At that time, the tongue piece 56 of the cylindrical portion 52 gradually expands in diameter toward the inner wall surface 58 of the bellows portion 42 under the action of centrifugal force, and finally, as shown in FIG. The piece 56 contacts the inner wall surface 58 of the bellows portion 42. Therefore, the joint boot 22 tries to be displaced in the direction of the arrow D by rotating with the axis B of the drive shaft 12 and the axis C of the driven shaft 18 inclined by a predetermined angle (eccentric state). Since 56 contacts the inner wall surface 58 of the bellows portion 42, the deviation of the bellows portion 42 in the direction of the arrow D is prevented. As a result, it is possible to prevent the shape of the joint boot 22 from being excessively deformed.

Further, as the tongue piece 56 expands in diameter or returns to the initial shape under the action of increasing / decreasing centrifugal force, the lubricating grease accumulated near the small-diameter mounting portion 44 of the joint boot 22 is removed from the inner member 20 side. Push back to. As a result, it is possible to obtain the effect of preventing the shortage of the lubricating grease that is caused by the long-term use of the constant velocity joint 10.

Next, FIGS. 4 and 5 show a state in which the joint boot 62 according to the second embodiment of the present invention is assembled to the constant velocity joint 64. The same components as those of the joint boot 22 according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The joint boot 62 according to the present embodiment is
This is different from the joint boot 22 according to the first embodiment in that the cylindrical portion 66 is formed separately from the small-diameter mounting portion 44, instead of being integrally formed.

The cylindrical portion 66 is formed along the outer peripheral portion of the driven shaft 18 which is separated from the small-diameter mounting portion 44 by a predetermined distance, and a plurality of slits 54 are defined around the shaft center by a predetermined angle. The cylindrical portion 66 is positioned and held by a snap ring (tightening member) 68 fitted to one end of the cylindrical portion 66 via an annular groove 70 formed in the driven shaft 18.

The joint boot 62 is preferably made of a rubber material or a synthetic resin such as urethane.
4 and 5, a joint boot made of synthetic resin is shown.

The joint boot 6 according to the present embodiment.
The constant velocity joint 64 in which 2 is assembled is the drive shaft 12
Outer race 7 that is integrally connected to and has an opening 72
4 and a ball 78 arranged in the outer race 74 via a ball cage 76.
The inner peripheral surface of the outer race 74 and the outer peripheral surface of the inner race 80 are in sliding contact with each other.

The operation and effects of the joint boot 62 according to this embodiment are the same as those of the joint boot 22 according to the first embodiment, as shown in FIG. Is omitted.

[0028]

According to the present invention, the following effects can be obtained.

That is, since one end of the tongue piece contacts the inner wall surface of the bellows portion, the deviation of the bellows portion is prevented and the shape of the joint boot can be prevented from being excessively deformed.

Further, by expanding and contracting one end of the tongue piece, the lubricating grease accumulated in the small-diameter mounting portion in the joint boot can be pushed back to the constant velocity joint side. There is an advantage of preventing the lack of lubricating grease.

[Brief description of drawings]

FIG. 1 is a sectional view of a constant velocity joint in which a joint boot according to a first embodiment of the present invention is assembled.

FIG. 2A is a cross-sectional view of the joint boot shown in FIG. 1, and FIG. 2B is a view taken in the direction of arrow X in FIG. 2A.

FIG. 3 is an operation explanatory view showing a state in which the tongue piece expands in diameter and abuts against the inner wall surface of the bellows portion under the action of centrifugal force in the joint boot shown in FIG. 1;

FIG. 4 is a sectional view of a constant velocity joint in which a joint boot according to a second embodiment of the present invention is assembled.

FIG. 5 is an operation explanatory view showing a state in which the tongue piece expands in diameter and abuts against the inner wall surface of the bellows portion under the action of centrifugal force in the joint boot shown in FIG. 4;

[Explanation of symbols]

10, 64 ... Constant velocity joint 12 ... Drive shaft 18 ... Driven shaft 22, 62
... Boots for joint 42 ... Bellows 44 ... Small diameter mounting 46 ... Large diameter mounting 48,5
0, 70 ... Annular groove 52, 66 ... Cylindrical portion 54 ... Slit 56 ... Tongue piece 58 ... Inner wall surface 60 ... Space portion 68 ... Snap ring

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuro Kariyama 19 Matsuyama-cho, Moka-shi, Tochigi Prefecture Honda Motor Co., Ltd. Tochigi Works

Claims (3)

[Claims] 1. A joint boot, one end of which is fitted to an outer peripheral portion of an outer member constituting a joint, and the other end of which is fitted to an outer peripheral portion of a shaft of a drive shaft or a driven shaft, the bellows-shaped boot. A bellows portion formed on the outer surface of the outer member, a small-diameter mounting portion formed on one end portion of the bellows portion and fitted on the outer peripheral portion of the shaft, and formed on the other end portion of the bellows portion on the outer peripheral portion of the outer member. A large-diameter mounting portion to be fitted and a plurality of slits surrounding the outer peripheral surface of the shaft and extending along the axial direction are formed separately, and one end portion of the bellow portion is expanded by expanding the diameter. A boot for a joint, comprising: a plurality of tongue pieces provided so as to be capable of contacting a wall surface. 2. The joint boot according to claim 1, wherein a plurality of tongue pieces are integrally coupled to the small diameter mounting portion, and the small diameter mounting portion, the bellows portion and the large diameter mounting portion including the plurality of tongue pieces are integrated. Boots for joints, which are characterized by being formed in a uniform manner. 3. The joint boot according to claim 1, wherein the plurality of tongue pieces are formed separately from the small diameter mounting portion, the bellows portion and the large diameter mounting portion, and the plurality of tongue pieces are separated from the small diameter mounting portion by a predetermined distance. A boot for a joint, characterized in that it is held on the outer peripheral portion of a shaft that is separated from the shaft via a tightening member.