JPH09317787A - Joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically supply lubricant to a lubricating chamber by providing a lubricant supply chamber partitioned from the lubricating chamber by a partition member permeable of the lubricant. SOLUTION: A lubricant supply chamber 33 is partitioned from a lubricating chamber 22 by a partition film 32. The partition film 32 is composed of a material permeating oil content of grease 34 and rubber materials such as chloroprene rubber and silicon rubber, thermoplastic resin such as polyethylene and polyester, or thermoplastic elastomer can be cited as materials. During rotation of torque transmission, there is some possibility that the content of the grease 34 permeates through material particles in a booth 20 so as to leak outside the lubricating chamber 22 by operation of the centrifugal force due to rotation or the increase in the internal pressure of the lubricating chamber 22 by heat generation of a sliding part. However, the grease of the lubricant supply chamber 33 penetrates the partition film 32 so as to be automatically supplied in the lubricating chamber 22 and therefore the quantity of the grease 34 necessary for lubrication of the sliding part can be secured in the lubricating chamber 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint used for a part of a torque transmission device of a vehicle, such as a drive shaft or a propeller shaft.

[0002]

2. Description of the Related Art Generally, a part of a vehicle torque transmission device,
For example, constant velocity joints are used for drive shafts and propeller shafts. This constant velocity joint is configured so that the rotation speed is always kept the same even if the connecting angle between the driving side member and the driven side member changes, and an example thereof is described in Japanese Utility Model Publication No. 7-44969. Has been done.

The constant velocity joint described in this publication is
An outer race as a first component attached to the transmission and an inner race as a second component attached to the propeller shaft are provided. A plurality of ball grooves are formed on the inner circumference of the outer race at predetermined intervals in the circumferential direction, and a plurality of ball grooves are formed on the outer circumference of the inner race at predetermined intervals in the circumferential direction. Then, a plurality of balls that are immersed in both the ball groove of the outer race and the ball groove of the inner race are arranged, and the outer race and the inner race are coupled so that torque can be transmitted by the engaging force between the outer race and the inner race and the ball. ing.

A boot as a sealing device made of a flexible material is arranged on one side of the outer race and the inner race in the axial direction, and a disc-shaped end cover is arranged on the other side of the axial direction. ing. The outer peripheral side of the tubular boot is fixed to one side of the outer race,
The inner peripheral side of the boot is fixed to the propeller shaft.
The end cover is fixed to the other side surface of the outer race. In this way, the space including the sliding portion formed at the connecting portion of the outer race and the inner race is sealed with the boot and the end cover to form the lubrication chamber, and grease as the lubricant is filled in the lubrication chamber. ing.

In the constant velocity joint constructed as described above, the output torque of the transmission is transmitted to the propeller shaft via the outer race, the balls and the inner race.
When the connection angle between the transmission and the propeller shaft changes, the outer race and the inner race relatively move to absorb the change in the connection angle.

On the other hand, the sliding portion formed at the connecting portion between the outer race and the inner race is lubricated by the grease enclosed in the lubricating chamber. Further, when the coupling angle between the transmission and the propeller shaft varies, the variation is absorbed by the elastic deformation of the boot and the grease sealing function is maintained.

[0007]

However, in the constant velocity joint described in the above publication, the grease is applied to the inner surface of the boot due to the action of centrifugal force due to the rotation or the rise of the internal pressure of the lubricating chamber due to the heat generation of the sliding portion. When pressed or when the boot absorbs the oil component of the grease and swells, the oil component of the grease may penetrate between the material molecules of the boot and leak to the outside of the lubrication chamber, so-called permeation leakage may occur. is there.

Then, the amount of grease required for lubricating the sliding portion decreases with the lapse of time, and there is a risk of causing flaking phenomenon of the sliding portion due to poor lubrication.

The present invention has been made in view of the above circumstances, and provides a joint capable of automatically replenishing a lubricating chamber with the lubricant when the amount of the lubricant enclosed in the lubricating chamber decreases. Is intended.

[0010]

In order to achieve the above object, the present invention is directed to a first constituent member and a second constituent member, which are movably connected to each other, the first constituent member and the second constituent member. In a joint provided with a lubricating chamber formed by sealing the sliding portion of the connecting portion with the member with a sealing device made of a flexible material, and a lubricant enclosed in the lubricating chamber, A lubricant replenishing chamber separated from the lubrication chamber by a penetrating partition member, and a lubricant contained in the lubricant replenishing chamber are provided.

Examples of the flexible material used for the sealing device in the present invention include rubber materials such as chloroprene rubber and silicon rubber, and thermoplastic resins or thermoplastic elastomers such as polyethylene and polyester. Examples of the partition member into which the lubricant can permeate include rubber materials, thermoplastic resins, and thermoplastic elastomers used in the above sealing device. Here, the materials used for the sealing device and the partition member may be the same or different.

According to the present invention, when the lubricant in the lubrication chamber penetrates between the material molecules of the sealing device and leaks to the outside of the lubrication chamber, that is, when so-called permeation leakage occurs, the lubricant is stored in the lubricant replenishment chamber. Since the lubricant permeates the partition member and is automatically supplied to the lubrication chamber, the reduction of the lubricant in the lubrication chamber is suppressed.
Therefore, it is possible to prevent the flaking phenomenon from occurring.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a configuration example of a constant velocity joint used in a connecting portion between a transmission of a vehicle and a propeller shaft. The constant velocity joint is
An outer race 1 as a first component attached to a companion flange (not shown) of the transmission and an inner race 3 as a second component attached to the tip of the propeller shaft 2 are provided.

A plurality of protrusions 4 are formed on the outer periphery of the outer race 1 at predetermined intervals in the circumferential direction, and each protrusion 4 has a shaft hole 6 penetrating in the direction of the axis 5 of the propeller shaft 2. Each is provided. Screws (not shown) are inserted into the shaft holes 6, respectively, and the companion flange and the outer race 1 are fixed by tightening the screws. Further, on the inner circumference of the outer race 1, a plurality of guide surfaces 7 having an arcuate section and a ball groove 8 having an arcuate section are arranged alternately in the circumferential direction.

On the other hand, the shaft portion 9 at the tip of the propeller shaft 2
Outer teeth 10 are formed on the outer circumference of the inner race 3, and inner teeth 11 and outer teeth 10 formed on the inner circumference of the inner race 3 are spline-fitted. Further, on the outer peripheral surface of the shaft portion 9 closer to the base portion 12 of the propeller shaft 2 than the outer teeth 10, an annular bulging portion 13 having an outer diameter larger than the inner diameter of the inner tooth 11 of the inner race 3 is formed. Has been done.

Further, an annular mounting groove 14 is provided on the tip side of the outer teeth 10 of the shaft portion 9, and the mounting groove 14 is provided.
A snap ring 15 is attached to the. The propeller shaft 2 and the inner race 3 are positioned and fixed relative to each other in the axis 5 direction by the bulging portion 13 and the snap ring 15 contacting both side surfaces of the inner race 3.

On the outer circumference of the inner race 3, a plurality of ball grooves 16 having an arcuate cross section are formed at predetermined intervals in the circumferential direction. Each ball groove 16 of the inner race 3 and each ball groove of the outer race 1 are formed. 8 are arranged at positions facing each other. Then, the balls 17 are separately rotatably inserted into the ball grooves 8 and 16 facing each other, and the outer race 1 and the inner race 3 are separated from each other by the engaging force between the balls 17 and the outer race 1 and the inner race 3. It is configured to be connected so that torque can be transmitted.

Further, an annular cage 18 is arranged between the outer race 1 and the inner race 3, and a plurality of holding holes 19 penetrating in the radial direction are provided in the cage 18 at predetermined intervals in the circumferential direction. The balls 17 are held by the holding holes 19. The shape of the outer peripheral surface of the cage 18 has a curvature corresponding to the shape of the guide surface 7 of the outer race 1, while the inner peripheral shape of the cage 18 has a curvature corresponding to the outer circumference of the inner race 3. Then, the inner race 3 is inserted into the cage 18, the cage 18 is inserted into the outer race 1, and the rolling of each ball 17 causes the outer race 1, the cage 18, and the inner race 3 to move relative to each other. , Outer race 1
The fluctuation of the connection angle between the propeller shaft 12 and the propeller shaft 12 is absorbed.

On the other hand, a boot 20 as a sealing device made of a flexible material and an end cover 21 made of metal are arranged on both sides of the outer race 1 and the inner race 3 in the direction of the axis 5. There is. With the boots 20 and the end covers 21, the outer race 1
And a sliding portion formed at the connecting portion between the inner race 3 and
For example, the sliding surface between the outer race 1 and the cage 18, the sliding surface between the cage 18 and the inner race 3, the outer race 1 and the inner race 3, and the cage 18 and the ball 1.
A lubrication chamber 22 including a sliding surface with 7 and the like is formed.

Examples of the flexible material used for the boot 20 include rubber materials such as chloroprene rubber and silicon rubber, and thermoplastic resins or thermoplastic elastomers such as polyethylene and polyester.

The boot 20 is integrally formed in a tubular shape, and is formed from an inner cylindrical portion 23 mounted on the outer periphery of the shaft portion 9 of the propeller shaft 2 and an end of the inner cylindrical portion 23 on the inner race 3 side. The curved portion 24 that is curved to the outside, and the outer tubular portion 2 that extends from the outer peripheral end of the curved portion 24 to the base portion 12 side of the propeller shaft 2.
5 is provided.

Then, the end portion of the inner cylindrical portion 23 is clamped by the clamp 26.
On the other hand, the end portion of the outer tubular portion 25 is sandwiched by an annular metal fitting 27, and the metal fitting 27 is fixed to the outer circumference of a sleeve 28 provided on the side surface of the outer race 1 on the propeller shaft 2 side. An O-ring 29 is attached between the metal fitting 27 and the sleeve 28. An annular projecting portion 30 centering on the axis 5 is formed on the side surface of the outer race 1 on the transmission side.

The end cover 21 is integrally formed of a metal plate, and has an outer cylindrical portion 21A and an annular flat portion 21B arranged at a right angle to the axis 5 from the inner peripheral end of the outer cylindrical portion 21A.
And a first taper portion 21C having a taper that reduces in diameter from the inner peripheral end of the flat portion 21B toward the transmission side, and extends from the inner peripheral end of the first tapered portion 21C toward the transmission side, and then the cage 18 A bent portion 21D that is bent in a U-shape in a direction that is reversed to the side, and a second tapered portion 21E that has a taper that reduces in diameter from the inner peripheral end of the bent portion 21D toward the transmission side,
The second taper portion 21E includes a disk portion 21F that closes the opening end on the small diameter side. The inner surface of the second taper portion 21E is inclined at a predetermined angle θ1 with respect to a line segment parallel to the axis 5.

The end cover 21 has its outer cylinder portion 21A fitted and fixed to the inner periphery of the protruding portion 30 of the outer race 1 so that its center coincides with the axis 5. Further, the outer periphery of a disc-shaped partition film 32 as a partition member is fitted and fixed in an annular mounting groove 31 formed inside the bent portion 21D. Therefore, the center of the partition film 32 coincides with the axis 5.

In this way, the second end cover 21
A lubricant replenishment chamber 33 surrounded by the taper portion 21E, the disc portion 21F and the partition film 32 is formed. The lubricant replenishment chamber 33 is separated from the lubrication chamber 22 by the partition film 32.

The partition film 32 is made of a material that allows the oil component of grease to permeate therethrough. Specific examples of the material include rubber materials such as chloroprene rubber and silicon rubber, thermoplastic resins such as polyethylene and polyester, and thermoplastic resins. An example is an elastomer. The material used for the partition film 32 may be the same as or different from the material used for the boot 20.

The lubricant replenishing chamber 33 and the lubricating chamber 22 are filled with grease 34 as a lubricant. This grease is obtained by using a lubricating oil as a base oil and uniformly dispersing a thickener into a semi-solid or solid state. The initial filling amount of the grease 34 in the lubricating chamber 22 is such that the filling radius r1 of the grease 34 at the time of the action of the centrifugal force is a circle (not shown) connecting the contact points of the balls 17 and the ball grooves 16 with each other. It is set to be less than or equal to the radius.
Further, the maximum radius r2 of the lubricant replenishment chamber 33 is
Is set to a value smaller than the enclosing radius r1 of the grease 34.

Next, the operation of the constant velocity joint configured as described above will be described. First, when the output torque of the transmission is transmitted to the outer race 1, this torque is transmitted to the propeller shaft 2 via the balls 17 and the inner race 3, and the vehicle runs. If the connection angle between the transmission and the propeller shaft 2 changes while the vehicle is running, the ball 17
And the outer race 1, the cage 18, and the inner race 3 move relative to each other in the direction of the axis 5 to absorb the change in the connecting angle between the transmission and the propeller shaft 2, thereby absorbing the outer race 1 and the propeller shaft 2. Constant speed rotation is maintained.

Further, a sliding portion of a connecting portion between the outer race 1 and the inner race 3, for example, a sliding surface between the outer race 1 and the cage 18, a sliding surface between the cage 18 and the inner race 3, a ball 17 and a ball. Groove 8 and ball groove 16
The sliding surface with the cage 18 and the like are lubricated by the grease 34 enclosed in the lubrication chamber 22. If there is a change in the connection angle between the transmission and the propeller shaft 2,
The boot 20 is elastically deformed to maintain its sealing function.

By the way, during transmission of torque, the grease 34 is pressed against the inner surface of the boot 20 or the boot 20 does not contact the grease 34 due to the action of centrifugal force due to rotation or the rise of the internal pressure of the lubricating chamber 22 due to the heat generation of the sliding portion. When the oil component absorbs and swells, the oil component of the grease 34 may penetrate between the material molecules of the boot 20 and leak to the outside of the lubricating chamber 22, so-called permeation leakage may occur.

However, according to this embodiment, the grease 34 enclosed in the lubricant replenishing chamber 33 permeates the partition film 32 and is automatically replenished to the lubricating chamber 22.
Thus, the amount of grease 34 required for lubricating the sliding portion can be secured. Further, in this embodiment, since the end cover 21 forming the lubricant replenishment chamber 33 is made of a metal into which the grease 34 cannot penetrate, the grease 34 does not permeate and leak from the end cover 21.

FIG. 2 is a diagram exemplifying a change with time of the grease 34 in the lubrication chamber 22 with respect to the vehicle travel distance in the vehicle equipped with the constant velocity joint. In FIG. 2, the lower limit of the amount of grease 34 filled in the lubrication chamber 22 during rotation, in other words, the upper limit of the filled radius r1 is larger than the radius of the circle connecting the contact points between each ball 17 and the ball groove 16 of the inner race 3. Set to a small value. Further, the upper limit of the amount of grease 34 enclosed, in other words, the lower limit of the enclosed radius r1 is, even when the load of grease 34 is applied to the inner surface of boot 20 by the centrifugal force acting on grease 34 during rotation.
The load is set to a value that does not reduce the durability of the boot 20.

In the example of FIG. 2, the amount of the grease 34 in the lubrication chamber 22 initially filled, that is, the radius r1 is set between the upper limit and the lower limit, and permeation leakage occurs as the traveling distance of the vehicle increases. However, from the lubricant supply chamber 33 to the lubrication chamber 2
2 is automatically replenished with grease 34, so that the amount of grease 34 filled in the lubrication chamber 22 should be maintained between the upper limit and the lower limit of the filling radius r1 even when the running distance of the vehicle exceeds a predetermined distance. It is possible to maintain good lubrication performance of the sliding part.

Therefore, the flaking phenomenon of the sliding portion formed at the connecting portion between the outer race 1 and the inner race 3 can be prevented in advance, and the torque transmission can be reliably performed to maintain the running performance of the vehicle. Further, since the grease 34 is automatically replenished in the lubrication chamber 22 due to the material characteristics of the partition film 32, maintenance is unnecessary.

Further, in the above embodiment, the lubricant replenishing chamber 33
The maximum radius r2 of the lubricating chamber 22 is set smaller than the enclosing radius r1 of the grease 34 in the lubricating chamber 22, and a centrifugal force acts on the grease 34 in the lubricating chamber 22. It is possible to prevent backflow to the 33 side.

Further, in the above embodiment, the lubricant replenishing chamber 3
Since the second taper portion 21E is located on the outer periphery of the grease 3, the grease 34 pressed against the inner surface of the second taper portion 21E by the action of the centrifugal force is separated from the grease 34 by the inclination of the second taper portion 21E. Since the grease 34 is pressed against, the penetration efficiency of the grease 34 is improved, and the function of supplying the grease 34 to the lubrication chamber 22 is further improved. Even if the angle θ1 of the inner surface of the second taper portion 21E is set to 0 degree, the function of replenishing the grease 34 is sufficiently maintained.

Further, in the above embodiment, the boot 20 is used.
The material of the partition film 32 and the material of the partition film 32 may be different, but if the same material is selected, the boot 20 to the lubricating chamber 22 can be selected.
Of grease 34 that permeates and leaks to the outside of the
Since the amount of the grease 34 that passes through 2 and is replenished to the lubrication chamber 22 becomes substantially the same, it becomes easier to maintain the proper amount of the grease 34 in the lubrication chamber 22 and the lubrication performance improves.

In this case, if the contact area between the grease 34 and the boot 20, that is, the permeation leakage area and the contact area between the partition film 32 and the grease 34, that is, the replenishment area are set to be the same, the lubrication chamber 22 The function of adjusting the amount of the grease 34 is further improved. Further, the wall thickness t1 of the partition film 32 can be set so that the amount of the grease 34 that permeates and leaks from the boot 20 and the amount of the grease 34 that permeates the partition film 32 and is replenished are substantially equal. is there.

Further, in this embodiment, since the partition film 32 is formed in a disc shape and the partition film 32 is arranged around the axis 5, the weight balance in the circumferential direction of the entire constant velocity joint is improved. It is maintained evenly, the inertial force is stable, and the torque transmission function can be favorably maintained. Further, since the partition film 32 is arranged inside the end cover 21, the partition film 32 does not contact the parts around the constant velocity joint, and abnormal noise and damage due to the contact are prevented.

Further, in the above embodiment, the outer race 1
And the inner race 3 are separately provided with a ball groove 8 having an arc-shaped cross section.
Although a fixed type constant velocity joint provided with a ball groove 16 and a ball groove 16 is shown, a linear type ball groove is provided in the outer race and the inner race, and a slide type constant velocity joint in which the balls are housed in this ball groove. It can also be applied to joints. Further, the constant velocity joint can be applied to a differential of a vehicle or a connecting portion between a wheel and a drive shaft. Furthermore, the boot that seals the lubrication chamber may be formed in a bellows shape.

[0041]

As described above, according to the present invention, the lubricant is replenished when the lubricant in the lubrication chamber penetrates between the material molecules of the sealing device and leaks to the outside of the lubrication chamber. The lubricant enclosed in the chamber penetrates the partition member and is automatically replenished in the lubricating chamber. Therefore, the lubrication performance of the sliding portion is maintained well, and the occurrence of flaking phenomenon can be suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a fixed type constant velocity joint according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a change over time in the grease in the lubricating chamber with respect to the traveling distance of the vehicle in the vehicle equipped with the constant velocity joint of FIG.

[Explanation of symbols]

 1 Outer Race (First Constituent Member) 2 Propeller Shaft 3 Inner Race (Second Constituent Member) 20 Boot (Sealing Device) 22 Lubrication Chamber 32 Partition Film (Partition Member) 33 Lubricant Supply Chamber 34 Grease (Lubricant)

Claims (1)

[Claims] 1. A sealing member made of a flexible material for a first constituent member and a second constituent member that are movably connected to each other, and a sliding portion of a connecting portion between the first constituent member and the second constituent member. In a joint provided with a lubrication chamber sealed by the device and a lubricant enclosed in the lubrication chamber, a lubricant replenishment chamber separated from the lubrication chamber by a partition member into which the lubricant can penetrate. And a lubricant housed in the lubricant replenishing chamber.