JP2844791B2 - Constant velocity joint - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a constant velocity joint, and more particularly to a constant velocity joint called a “rebro” or “cross glove type” suitable for a drive system of a vehicle.

(Prior Art) As shown in FIG. 5, there is a constant velocity joint called a rebro or cross glove type.
No. 62-31724). The constant velocity joint includes a cylindrical outer ring 10 having a plurality of ball grooves 11 on an inner peripheral surface, and a ball groove 11.
An inner ring 12 having the same number of ball grooves 13 on the outer peripheral surface and connected to the first shaft 14, and a ball groove 11 of the outer ring which faces when the inner ring 12 is inserted into the outer ring 10.
And a plurality of balls 16 arranged one by one in a ball groove 13 of the inner ring, a cage 18 for holding the balls 16, a second shaft 20 having a flange 21 coupled to the outer ring 10,
And an end cover 22 attached to the end cover.

The end cover 22 is attached to the outer ring 10 on the side opposite to the side where the first shaft 14 extends, and the boot 24 is attached across the outer ring 10 and the first shaft 14. Grease for lubricating the ball 16 is held by the end cover 22 and the boot 24. Outer ring 10 and second shaft
20 are connected to each other by a plurality of bolts 26 which are screwed into the flange 21 through the outer ring.

In the constant velocity joint, a ball groove is formed on the inner peripheral surface of the outer ring 10.
Since the outer ring 10 is provided and the outer ring 10 and the flange 21 of the second shaft 20 are connected by the bolts 26 penetrating the part of the outer ring 10 that is out of the ball groove 11, the end cover 22 As shown in FIG. 6A, the bent outer peripheral portion 23 is directly pressed into the outer race 10, or as shown in FIG. 6B, the outer race 10 is cut by reducing the thickness corresponding to the thickness of the end cover 22. The diameter portion 9 is provided, and the outer peripheral portion 23 of the end cover 22 is press-fitted therein and attached to the outer ring 10.

On the other hand, there is also a constant velocity joint called a tripod type (for example, Japanese Utility Model Publication No. Sho 62-18742). In this constant velocity joint, the outer ring is formed to be relatively thin, and the outer ring and the second shaft are connected to each other. There is no space in the outer ring to insert bolts to connect Therefore, flanges projecting radially outward from the outer ring are provided at intervals in the circumferential direction, and the second shaft is provided with a flange projecting radially outward so as to face the flange, Bolts extend through these flanges. In this point, it is different from the above-mentioned REVLO type constant velocity joint.

(Problems to be Solved by the Invention) Since the first shaft 14 and the second shaft 20 must be located on the same axis, alignment is required prior to the connection between the outer ring and the flange of the second shaft. There is a need to. For this centering, it is conceivable to use the bolt 26 itself for connecting the outer ring 10 and the flange 21, use a separately driven knock pin, or use a wheel.

When aligning with the bolt itself, satisfactory alignment accuracy cannot be ensured unless the accuracy of the bolt hole and the bolt is made very high. However, increasing the accuracy of the bolt holes and bolts increases costs.

In centering using a knock pin, in the case of the REVLO type constant velocity joint, the outer ring is provided with a ball groove and a bolt hole, so there is little room for driving the knock pin, and a sufficient tightening force is ensured and high accuracy is achieved. It is difficult to align.

6 (a), the outer peripheral portion 23 of the end cover 22 and the bent end of the flange 21 are fitted together, or as shown in FIG. 6 (b). By fitting the end of the flange 21 extending beyond the bent end 23 of the cover and the outer ring 10,
Can be aligned. However, in the former case, since the end cover is interposed, alignment with high accuracy cannot be expected. In the latter case, since the end of the flange is longer than the end cover, the size of the flange is increased. Moreover, since the press-fitting depth is large, workability at the time of press-fitting is greatly reduced.

Therefore, an object of the present invention is to provide a constant velocity joint that enables highly accurate air-oil connection between the outer ring and the flange of the second shaft by attaching the end cover to an appropriate position of the outer ring. .

(Means for Solving the Problems) According to the present invention, a cylindrical outer race having a plurality of ball grooves on an inner peripheral surface is connected to a first shaft having the same number of ball grooves on the outer peripheral surface as the ball grooves. An inner ring, a plurality of balls arranged one by one in the ball groove of the outer ring and the ball groove of the inner ring which are respectively opposed to each other when inserted into the inner ring and the outer ring; and a cage holding these balls. A constant velocity joint including a second shaft having a flange coupled to the outer ring by coupling means penetrating the outer ring, and an end cover attached to the outer ring. The outer race and the flange are joined together by fitting the outer race to the flange. The outer ring has a recess capable of press-fitting the end cover, and the recess is provided on an end surface of the outer ring facing the flange, and extends radially outward from an inner peripheral surface of the outer ring. , Extending from the outer peripheral surface of the outer race to a portion spaced inward in the radial direction. The end cover has a contact portion that maintains liquid tightness with the outer race, and a press-fit portion that protrudes from the contact portion and is press-fitted into the recess.

In a preferred aspect, a seal member is provided between the contact portion of the end cover and the outer ring. In another preferred aspect, the press-fitting portion of the end cover is formed such that there is a clearance between the press-fitting portion and the outer peripheral wall surface of the recess before the press-fitting into the recess, and the press-fitting portion is formed when the press-fitting is performed. It is formed so that it may be pressed against the wall surface.

(Operation and Effect) By press-fitting the end cover into a recess provided on one end surface of the outer ring, the grease filling the outer ring is prevented from leaking on the end cover side. Thereafter, the outer ring and the flange of the second shaft are connected by bolts or other connecting means.

Since the outer peripheral surface of the outer ring and the flange of the second shaft are connected by air heating, alignment of the two shafts is possible. In this case, the joining is accurate because no end cover is interposed. And since the length of the wax may be short, the labor for processing the wax is small.

Since the centering of the two shafts can be performed without using the coupling means itself, it is not necessary to increase the accuracy of, for example, a single bolt hole or a bolt itself, and it is possible to suppress an increase in cost associated therewith. On the other hand, machining for the outer peripheral surface of the outer race and the flange of the second shaft can be made relatively inexpensively, so that the cost can be reduced as a whole.

With the end cover assembled with the constant velocity joint,
Since it is not exposed to the outside, surface treatment such as painting of the end cover becomes unnecessary, and in this regard, cost can be reduced.

The end cover has different functions depending on the part, such as maintaining the liquid tightness between the end ring and the outer ring at the abutment part and press-fitting into the recess of the outer ring at the press-fit part. Can be processed. Thereby, maintenance of liquid tightness and fixing by press fitting can be easily performed.

According to a preferred aspect, since the sealing material is arranged between the contact portion of the end cover and the outer ring, the sealing performance can be further improved without increasing the processing accuracy of the contact portion.

According to another preferred aspect, since the press-fitting portion has a clearance from the outer peripheral wall surface of the recess, the size of the clearance is predetermined, whereby the positioning of the end cover prior to the press-fitting is performed by the press-fitting portion. This makes it easy to position the end cover. Also, when press-fitting the end cover, even if the press-fitted portion expands outward and is strongly pressed against the wall surface of the recess, the deformation distortion to the contact portion can be suppressed as much as possible, and a very good Liquid tightness can be ensured.

(Embodiment) The basic structure of the constant velocity joint shown in FIG. 1 is the same as the conventional one shown in FIG. That is, the constant velocity joint includes a cylindrical outer race 10 having a plurality of ball grooves 11 on the inner peripheral surface, and an inner race coupled to the first shaft 14 having the same number of ball grooves 13 as the ball grooves 11 on the outer peripheral surface. When the inner ring 12 is inserted into the outer ring 10, the ball groove 11 of the outer ring 10 and the ball groove 13 of the inner ring 12 which are opposed to each other,
It includes duplicate balls 16 arranged individually, a cage 18 for holding the balls 16, a second shaft 20 having a flange 21 coupled to the outer ring 10, and an end cover 30 attached to the outer ring 10.

As shown in FIG. 2, the outer race 10 is formed of a cylinder having a relatively short length in the axial direction, and has six ball grooves 11 on the inner peripheral surface. The ball groove 11 is inclined at a predetermined angle with respect to the rotation axis of the outer ring 10. Outer ring 10 out of ball groove 11
Is provided with a hole 27 through which a bolt 26 as a coupling means passes.

The inner ring 12 is formed in a substantially spherical shape as a whole, and has six ball grooves 13 on the outer peripheral surface. Inner ring 12 to outer ring 10
When inserted, the ball groove 13 of the inner ring 12 faces the ball groove 11 of the outer ring 10, but the ball groove 13 of the inner ring 12 intersects the ball groove 11 of the outer ring 10 so as to intersect with the rotation axis. At a predetermined angle. This configuration is known as a rebro joint. The shaft 14 is spline-coupled to the inner race 12 and is prevented from falling off by a snap ring 32.

The flange 21 integral with the second shaft 20 has a hole 21a slightly hollowed out from the end face facing the outer race 10. The outer ring 10 is soldered and fitted into the hole 21a, and the two shafts 14, 20 are aligned.

The outer race 10 has a recess 34 on the end face 21b facing the flange 21. The depth of the recess 34 is determined by a sealing material interposed between the end cover 30 and the outer ring 10. That is, when the sealing material is liquid, the depth of the recess 34 is
In the case where the sealing material is a plate made of rubber or synthetic resin, the depth is set such that an appropriate interference is given to the sealing material after assembly. This recess 34
The ball grooves 11 extend outward in the radial direction of the ten ball grooves 11 and to radially inward portions of the outer peripheral surface. That is, the recess 34
Extends radially outward from the inner peripheral surface of the outer ring 10 and radially inwardly spaced from the outer peripheral surface of the outer ring 10.

The end cover 30 is pressed into the recess 34 of the outer race 10. Third
In the embodiment shown in the figure, the end cover 30 has a contact portion 31a facing the outer ring 10 via a sealing material in the recess 34.
And a plurality of press-fitting portions 31b protruding from the contact portion 31a and provided in the circumferential direction, and a cover portion 31c recessed from the contact portion 31a. A portion of the contact portion 31a corresponding to the bolt hole 27 of the outer ring 10 is a semicircular notch 31d.

The end cover 30 is, as shown in FIG.
Is applied to the sealing material 40, and the outer ring 10 is
Press-fit. As described above, a plate-like material of rubber or synthetic resin, a liquid material, or the like can be used as the sealing material 40.

As described above, by press-fitting the end cover 30 into the outer race 10 with the seal material 40 interposed therebetween, liquid tightness can be obtained by the seal material 40.
Only needs to be firmly attached to the outer ring 10, and there is no need to secure liquid tightness by the press-fitting portion. That is, the function of fixing by press fitting and the function of maintaining liquid tightness can be separated. As a result, as shown in FIG. 3, press-fitting by a plurality of press-fitting portions 31b arranged in the circumferential direction of the end cover 30 becomes possible, and a notch 31d may be provided in a portion corresponding to the bolt hole 27. ,
Liquid tightness can be secured. This is because the concave portion 34 of the outer ring 10 can be formed substantially circular regardless of the presence or absence of the bolt hole 27, which is an excellent advantage in processing the concave portion 34.

Also, if the end cover 30 is press-fitted while the contact portion 31a of the end cover 30 is in contact with the seal material 40, the contact portion 31a is strongly pressed against the seal material 40 by press-fitting the end cover 30. , A sufficient sealing surface can be secured. This means that, in other words, the thickness of the sealing material 40 can be made as thin as possible even when the sealing material 40 is formed of a plate-like material. Therefore, the depth of the recess 34 provided in the outer ring 10 can be reduced.

To press-fit the end cover 30 into the recess 34 of the outer ring 10,
As shown in FIG. 4, it is preferable that the press-fitting portion 31b is formed by being slightly bent so that a clearance between the wall surface 35 of the recess 34 and the end cover 30 can be formed. This is not only the case where the end cover 30 is press-fitted with only the plurality of press-fitting portions 31b as in the embodiment, but also the case where the end cover 30 is press-fitted into the recess 34 by a press-fitting portion provided on the outer peripheral edge. apply. In this way, the end cover prior to press fitting
The positioning within the recess 34 of the 30 is easy.

When the end cover 30 is arranged at a predetermined position in the recess 34 of the outer ring 10 and the press-fit portion 31b and the contact portion 31a are pressed by a press, the press-fit portion 31b spreads outward, and the end of the press-fit portion 31b Wall 35
Pressing strongly to complete the press fit.

After being press-fitted into the outer ring 10 of the end cover 30, the flange 21 of the second shaft 30 and the outer ring 10 are joined by means of soldering, and the two shafts 14 and 20 are aligned.
A bolt 26 is inserted into the flange 21 and screwed into the flange 21 to assemble a constant velocity joint. After or prior to assembling, the boot 24 is wrapped around the outer race 10 and the first shaft 14.

When the end cover 30 includes a plurality of press-fit portions 31b as in the above-described embodiment, the following effects can be obtained.

When press-fitting the end cover 30, even if the press-fitting portion 31b spreads outward and is strongly pressed against the wall surface 35 of the recess 34, the contact portion 31b
The deformation strain to 31a can be minimized, and the contact part 31a
A very good sealing property can be secured.

If the deformation of the press-fitting portion 31b at the time of press-fitting is designed to be within the elastic displacement, the end cover can be reused.

Since the end cover 30 is attached by a plurality of press-fitting portions 31b, the contact portion 31a of the end cover corresponds to a value obtained by subtracting the depth of the recess 34 from the sum of the thickness of the sealing material and the thickness of the end cover. , Can protrude from the outer ring 10. When the flange 21 of the second shaft 20 is coupled to the outer race 10 in this state, the sealing material receives a force via the protruding portion, so that the sealing performance is further improved, and the flange 21
When the is removed, the protrusion returns to the initial state due to the elasticity of the end cover and the sealing pressure. Therefore, before the flange 21 is joined, even if the force to be applied at the time of press-fitting is determined so that a sealing pressure that does not allow grease to leak to the sealing material 40, it is possible to secure a sufficient sealing pressure at the time of use. it can. This makes it possible to reduce the force to be applied at the time of press-fitting.

[Brief description of the drawings]

FIG. 1 is a sectional view of a constant velocity joint according to the present invention, FIG. 2 shows an outer ring, (a) is a sectional view, (b) is a left side view showing a half, and FIG. 3 is an end cover. It indicates
(A) is a sectional view taken along the line AA of (b), (b)
Is a right side view showing a right half, FIG. 4 is an enlarged sectional view showing a state before press-fitting an end cover and an outer ring, FIG. 5 is a sectional view of a conventional constant velocity joint, FIGS. b) is an enlarged cross-sectional view of the solder joint. 10: Outer ring, 11: Ball groove, 12: Inner ring, 13: Ball groove, 14: First shaft, 16: Ball, 18: Cage, 20: Second shaft, 21: Flange, 21a: Hole 21b: End face 26: Bolt, 30: Ent cover, 31a: Contact part 31b: Press-fit part 34: Concave part.

Continued on the front page (56) References Japanese Utility Model Sho 58-30029 (JP, U) Japanese Utility Model Sho 57-3132 (JP, U) Japanese Utility Model Sho 58-7927 (JP, U) Japanese Utility Model Sho 62-18742 (JP) , Y2) (58) Field surveyed (Int.Cl. ⁶ , DB name) F16D 3/20-3/229 F16D 3/84

Claims (3)

(57) [Claims] A cylindrical outer ring having a plurality of ball grooves on an inner peripheral surface thereof; an inner ring coupled to a first shaft having the same number of ball grooves on the outer peripheral surface; A plurality of balls arranged one by one in the ball groove of the outer ring and the ball groove of the inner ring which are opposed to each other when inserted into the outer ring, a cage holding the balls, and a connection penetrating the outer ring A constant velocity joint comprising: a second shaft having a flange coupled to the outer ring by means; and an end cover attached to the outer ring, wherein the outer ring and the flange fit the outer ring into the flange. The outer ring has a recess capable of press-fitting the end cover, the recess is provided on an end surface of the outer ring facing the flange, and The end cover extends radially outward from the inner peripheral surface of the outer ring to a portion radially inward from the outer peripheral surface of the outer ring, and the end cover has a liquid tightness between the outer ring and the outer ring. A constant-velocity joint, comprising: a contact portion for maintaining the pressure; and a press-fit portion protruding from the contact portion and being press-fitted into the recess. 2. The constant velocity joint according to claim 1, further comprising a seal member disposed between said contact portion of said end cover and said outer race. 3. The press-fit portion of the end cover has a clearance between the press-fit portion and the outer peripheral wall of the recess before press-fitting into the recess, and the press-fit portion of the recess when press-fit into the recess. The constant velocity joint according to claim 1, wherein the constant velocity joint is formed so as to be pressed against a wall surface.