JPH04171319A - Constant-velocity universal joint that possesses vibration damping function - Google Patents

Abstract

PURPOSE:To obtain stabilized vibration damping effect and realize miniaturization and weight reduction by enclosing viscous fluid in the space between the fitting faces of an outer tube and an inner tube, and providing a rotation restricting system that restricts relative rotation of the outer tube and the inner tube due to elastic deformation of an elastic member at a fixed angle between the inner and outer tubes. CONSTITUTION:A torsion bar 7 as an elastic member is formed at the blocking end 3a of an inner tube 3. This torsion bar 7 is inserted into a bar inserting hole 5, and its front end part is fixed and brought to a stop by a joint stem 4. A pair of oil seals 10, 11 are built in at the both end parts in axial direction in the space between the fitting surfaces of the outer tube 2 and the inner tube 3, and viscous fluid is enclosed in the fitting surfaces sealed with the oil seals 10, 11. The outer tube 2 and the inner tube 3 perform relative rotation by the distortion of the torsion bar 7, and a rotation restricting system 20 that restricts that rotation angle at a fixed angle is provided between the facing surfaces at the blocking end 2a of the outer tube 2 and the blocking end 3a of the inner tube 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a constant-velocity diagonal with a vibration damping function that is incorporated into a drive shaft of an automobile.

[Conventional technology]

Japanese Patent Publication No. 60-25282 has been published as a means to solve the problem of noise and vibration in automobiles involving the drive system. Figures 4 and 5 show the drive shaft device described in the above publication. The joints 40 and 41 are connected by a torsion bar 42, and a torsion bar is attached to the outside of the torsion bar 42.
42, the first cylindrical body 43 and the second cylindrical body 44 having high torsional rigidity are inserted, and each cylinder 43, 44 is attached to the torsion bar 42.
A friction plate 48 is fixed to both ends of the cylindrical body 43 , 44 is connected to flanges 45 , 46 provided at opposite ends of each cylinder body 43 , 44 by bolts 47 , and is movable in the axial direction along the bolts 47 .
is brought into pressure contact with the flange 45 of the first cylindrical body 43 by the elasticity of the spring 49.

Further, the bolt insertion hole 50 formed in the flange 45 of the first cylindrical body 43 is made into an arc-shaped elongated hole 50, and the end of the elongated hole 50 and the bolt 47 are brought into contact with each other to connect the first cylindrical body 43 and the second cylinder. The relative rotation angle of the body 44 is limited.

According to the drive shaft device described above, when input torque is applied, the torsion bar 42 is significantly twisted and the first cylinder 43 and the second cylinder 44 rotate relative to each other. At this time, the rotational torque fluctuations acting on the drive shaft 50 can be alleviated by the twisting work of the torsion bar 42. If the torsion bar 42 generates torsional vibration due to its own torsional restoring force, this vibration is immediately attenuated by the frictional work performed between the flange 45 and the friction plate 48.

[Problems to be Solved by the Invention] Incidentally, the drive shaft device described above is configured to damp vibrations caused by torsion of the torsion bar 42 by using a dry friction mechanism formed by pressure contact between the flange 45 and the friction plate 48. However, there is a problem in that it is difficult to tune and stabilize the vibration damping performance.

Furthermore, since the shaft portion between the pair of constant velocity joints 40 and 41 has a double structure, an increase in the weight of the drive shaft assembly and an increase in the shaft diameter are unavoidable.

The technical object of the present invention is to solve the above problems, stabilize the vibration damping effect, and reduce the size and weight.

[Means for Solving the Problems] In order to solve the above problems, in the present invention, the joint outer ring is formed of an outer cylinder having a joint stem and an inner cylinder fitted inside the outer cylinder, and the outer cylinder A viscous fluid is sealed between the fitting surfaces of the inner cylinder and the outer cylinder, and the outer cylinder and the inner cylinder are connected by an elastic member that is elastically deformed by the relative rotation of the outer cylinder and the inner cylinder. A configuration was adopted in which a rotation limiting mechanism was provided between the inner and outer cylinders to limit the relative rotation of the outer and inner cylinders to a certain angle.

[Operation] When an input torque acts on the joint stem of the outer cylinder, the torsion bar is twisted and the outer cylinder and the inner cylinder rotate relative to each other. At this time, the torsion bar with low torsional rigidity can alleviate torque fluctuations acting on the drive shaft.

At this time, if vibrations occur due to the low torsional rigidity of the torsion bar, the vibrations are damped by the viscous resistance generated by the relative rotation of the two cylinders.

When the rotational torque is large, the rotation limiting function is engaged, and the rotational torque is transmitted from the retaining portion to the inner cylinder, and the rotational torque is also transmitted from the elastic member to the inner cylinder.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

As shown in FIG. 1, the outer ring 1 consists of an outer cylinder 2 and an inner cylinder 3 fitted inside the outer cylinder 2. The outer tube 2 and the inner tube 3 have closed ends 2a and 3a, respectively, and the closed end 2a of the outer tube 2 is provided with a joint stem 4, and the joint stem 4 is formed with an axial bar insertion hole 5. has been done.

On the other hand, a torsion bar 7 as an elastic member is formed at the closed end 3a of the inner cylinder 3. This torsion bar 7 is inserted into the bar insertion hole 5, and its tip end is prevented from rotating by the joint stem 4. In order to prevent the torsion bar from rotating, serrations 8 are formed on the outer periphery of the tip of the torsion bar 7 and the inner circumference on the back side of the bar insertion hole 5, but instead of the serrations 8, the tip of the torsion bar 7 is It may be pinned to the tostem 4.

A pair of oil seals 10.11 are fitted at both ends in the axial direction between the fitting surfaces of the outer cylinder 2 and the inner cylinder 3, and a viscous A fluid 12 is enclosed.

The outer cylinder 2 and the inner cylinder 3 rotate relative to each other due to the torsion of the torsion bar 7, and a rotation limiting mechanism 20 that limits the rotation angle to a certain angle is connected to the closed end 2a of the outer cylinder 2 and the closed end 3a of the inner cylinder 3.
It is provided between the opposing surfaces of.

As shown in FIG. 2, the rotation limiting mechanism 20 includes a plurality of four parts 21 provided at the closed end of the inner cylinder 3 at required intervals in the circumferential direction, and a plurality of recesses 21 provided at the closed end 2a of the outer cylinder 2. In this example, a plurality of protrusions 22 are formed to be inserted into the recess 2, and a rotational clearance A is provided between the protrusions 22 and the recess 21.
The formation positions of the protrusions 1 and 22 may be reversed.

A plurality of ball grooves 1 in the axial direction are formed on the cylindrical inner surface of the inner cylinder 3.
3 is formed, and a plurality of ball grooves 15 are provided on the outer diameter surface of the inner ring 14 incorporated inside the inner cylinder 3, and the balls 16 can be freely moved between the ball grooves 13 and 15 facing each other in the radial direction. The pole 16 is held by a retainer 17.

Figure 3 shows a constant velocity joint CV J having the above configuration.
A drive shaft device is shown in which the inner ring 14 of a fixed type constant velocity joint (CVJ) is connected by a transmission shaft 30.

Constant velocity join of one of the above drive shaft devices) CV J +
When rotational torque is input to the joint stem 4, the torsion bar 7 is twisted greatly, and the rotational torque fluctuation input to the joint stem 4 is alleviated by the twisting. Further, the torsion of the torsion half causes the outer cylinder 2 and the inner cylinder 3 to rotate relative to each other, and due to the relative rotation, the viscous fluid 12 sealed between the outer cylinder 2 and the inner cylinder 3 is sheared, and the viscous fluid 12 is sheared. Vibrations caused by torsion of the torsion bar 7 are damped by the shear resistance.

When the torsion of the torsion bar 7 further increases and the outer cylinder 2 and the inner cylinder 3 rotate largely, the protrusion 22 engages with the side surface of the recess 21. This retention prevents excessive twisting of the torsion bar 7.

In addition, the rotational torque input to the joint stem 4 is
The power is transmitted from the above-mentioned retaining portion to the inner cylinder 3 and also from the torsion bar 7 to the inner cylinder 3.

As mentioned above, the joint stem 4 is twisted by the torsion bar 7 incorporated inside the constant velocity joint CVJ.
Since it is configured so that fluctuations in the rotational torque input to the torsion bar 7 can be alleviated, and the vibrations caused by the torsion of the torsion bar 7 are attenuated by the viscous fluid 12 sealed between the inner and outer cylinders 2 and 3, the joint with the other joint can be reduced. A normal small-diameter shaft could be used for the shaft.

〔Effect of the invention〕

As described above, according to the constant velocity joint □ of the present invention, the vibration caused by the torsion of the elastic member is attenuated by the shear resistance of the viscous fluid sealed between the outer cylinder and the inner cylinder, so that stable vibration can be achieved. A damping effect can be obtained.

Furthermore, an elastic member is incorporated inside the joint to alleviate rotational torque, and vibrations caused by the torsion of the elastic member are attenuated by the shear resistance of the viscous fluid sealed between the fitting surfaces of the inner and outer cylinders. The shaft portion formed by incorporating the diq indium can be made smaller and lighter.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing one embodiment of the constant velocity joint according to the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing a conventional drive shaft device, and FIG. 5 is a cross-sectional view taken along line V-V in FIG. 4. 1...Joint outer ring, 2...Outer cylinder,
3... Inner cylinder, 7... Torsion bar, 12... Viscous fluid, 20...
... Rotation limiting mechanism. Patent applicant NT Co., Ltd.

Claims (1)

[Claims] (1) The joint outer ring is formed by an outer cylinder having a joint stem and an inner cylinder fitted inside the outer cylinder, and a viscous fluid is sealed between the fitting surfaces of the outer cylinder and the inner cylinder, and the outer cylinder and the inner cylinder are The outer cylinder and the inner cylinder are connected by an elastic member that is elastically deformed by relative rotation, and a rotation restriction mechanism that limits the relative rotation of the outer cylinder and the inner cylinder to a certain angle due to the elastic deformation of the elastic member is installed inside and outside. Constant velocity joint with vibration damping function installed between cylinders.