JPH07301247A - Constant velocity joint - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a constant velocity joint which can contribute to improvement of lubricity around a ball fitted into a support hole of a cage member. [Structure] An annular cage member (10) slidably contacting the inner peripheral surface (3A) of the external connecting member (3) and the outer peripheral surface (7A) of the internal connecting member (7), and at circumferentially equally spaced positions A rolling groove (4) which is rotatably fitted in the provided support hole (11) and is provided on the inner peripheral surface (3A) and the outer peripheral surface (7A).
And a ball (5) rolling along (9),
A lubricating groove (lubricant holding groove) 20 was provided on at least the sliding contact surface of the support hole (11) of the cage member (10).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity joint, and more particularly to a constant velocity joint used as a universal joint for a drive shaft of a vehicle.

[0002]

2. Description of the Related Art In a vehicle drive shaft or the like, the rotation of the two shafts is transmitted at a constant speed even if the intersection angle (bending angle) between the drive shaft and the passive shaft (driven shaft) becomes large. A constant velocity universal joint (constant velocity joint) has been used for. Since constant velocity joints of this kind are exposed to severe operating conditions,
It is connected through a plurality of durable steel balls which are lubricated with grease, and one example thereof is JP-A-63-38.
Some are disclosed in Japanese Patent No. 718.

In this conventional example, a plurality of axial grooves are provided on both the inner ring (internal connecting member) and the outer ring (external connecting member), and the steel balls held in the cage can be driven in these grooves. In a constant velocity joint that is designed to be held,
The surface of the pocket provided in the cage for holding the steel balls is ground so that a solid lubricant film is formed on the pockets and the surfaces of the grooves and the steel balls are made relatively rough. By forming an appropriate lubricant film between the steel ball and the steel ball and between the steel ball and the cage pocket holding the steel ball, it is possible to suppress the temperature rise of the steel ball and prolong the life.

[0004]

However, in the above-mentioned conventional example, in order to maintain constant velocity, the above-mentioned steel balls are held in the cage so that they are always positioned on the bisector of the bending angle θ ° of the shaft. The cage pocket (steel ball support hole) and the steel ball are fitted together with a tight margin of several μm maintained to prevent play at that position. Therefore, the lubricant film formed in the cage pocket is peeled off during assembly of the steel balls, and not only the lubrication effect of the corner is lost, but also a process for forming a solid lubricant film in the cage pocket. Is required, which causes a cost increase.

An object of the present invention is to provide a constant velocity joint capable of improving the lubricity around a steel ball in order to solve such a conventional problem.

[0006]

In order to achieve the above object, the present invention provides an annular cage member which is in sliding contact with the spherical inner peripheral surface of the external connecting member and the spherical outer peripheral surface of the internal connecting member. Via balls that are rollably fitted into a plurality of support holes provided at equal circumferential positions of the cage member and that roll along the rolling grooves provided in the external connection member and the internal connection member. In a constant velocity joint that is flexibly connected,
A lubricating groove for guiding a lubricant is provided on at least a sliding contact surface of the cage member, which is in sliding contact with the ball, of the support hole.

[0007]

According to the present invention, since the lubricating groove for guiding the lubricant is provided on at least the sliding contact surface of the cage member in which the ball slides, the ball is prevented from having a bending angle between the rotating shafts. Is held in the support hole of the cage member and rolls in a state of sliding contact with the sliding contact surface, and the balls are provided on the spherical inner peripheral surface of the outer connecting member and the spherical outer peripheral surface of the inner connecting member. Although it rolls along the moving groove, it is generated at least between the ball and the supporting hole sliding contact surface because the lubricant is always guided to the lubricating groove provided on the sliding contact surface of the supporting hole. Prevent wear.

[0008]

Embodiments of the present invention will now be described in detail and specifically with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. It should be noted that this example shows an example of application to a Barfield type constant velocity joint. Here, 1 is a constant velocity joint thereof, 2 is a drive shaft, 3 is an external connection member integrally formed with the drive shaft 2, and 4 is a spherical inner peripheral surface 3A of the external connection member 3 at equal positions in the circumferential direction. A concave curved groove (hereinafter referred to as a first rolling groove) formed to keep the steel ball 5 rolling in the direction along the paper surface, 6 is a driven shaft, 7 is a driven shaft 6 via a snap ring 8 The fixed internal connection member 9 is provided at a position corresponding to the first rolling groove 4 on the spherical outer peripheral surface 7A of the internal connection member 7, and is a convex curved groove for keeping the steel ball 5 rotatably ( Hereinafter referred to as the second rolling groove).

The steel ball 5 is rotatably held by being fitted into a steel ball support hole 11 formed in a radial direction at circumferentially equal positions of a cage member 10 formed in the shape of a drum body. . On the other hand, the first rolling groove 4 and the second rolling groove 9 have a substantially hemispherical cross section orthogonal to the rolling direction, and the bottoms of the first rolling groove 4 and the second rolling groove 9 have points A on the axes of the drive shaft 2 and the driven shaft 6, It is formed in an arc shape centered on B. Also, O
Is the outer peripheral surface 10A and the inner peripheral surface 10B of the cage member 10.
Indicates the arc center for.

Thus, in the cage member 10, the outer peripheral surface 10A of the cage member 10 is in sliding contact with the inner peripheral surface 3A of the outer connecting member 3, and the cage member inner peripheral surface 10B is the outer peripheral surface 7A of the inner connecting member 7.
Sliding contact with both the shafts 2 and 3 even if the bending angle θ ° maintained between the drive shaft 2 and the driven shaft 6 changes from 180 ° shown in FIG. 1 to that shown in FIG. Can always be kept in a bent state with the center of curvature O of the arc as the center.

As described above, the centers of curvature A and B of the arc formed by the bottom of the first rolling groove 4 and the bottom of the second rolling groove 9 are equidistant from the center O on the axis mn shown in FIG. It is in. Then, as the bending angle θ ° is generated, the steel ball 5
(In the case of this example, one for each rolling groove forming a pair, totaling 6)
Respectively roll along the first rolling groove 4 and the second rolling groove 9, but regardless of the bending angle θ °, the steel ball 5 has the center thereof as shown in FIG. It is located on a plane T orthogonal to the plane of the paper including the bisector of the bending angle θ °, and the rotational force is smoothly and uniformly transmitted from the drive shaft 2 to the driven shaft 6 via these steel balls 5. be able to.

FIG. 3 shows a structural example of the cage member 10 according to the present invention. The steel ball support hole 11 of the cage member is shown in FIGS.
As shown in FIG.
Is fitted with a slight press fit so that there is no play. 2
Reference numeral 0 denotes a plurality of lubricant holding grooves provided around the steel ball support hole 11 of the cage member 10. Although the four lubricant retaining grooves 20 are provided only on the surface of the steel ball 5 on the side orthogonal to the rolling direction in FIG. 3, the groove direction and the like are formed so that the lubricant can be easily guided. Any form may be used as long as it is provided, and it may be provided also on the surface on the side parallel to the rolling direction. In addition, the groove 20 is formed on the outer peripheral surface 10 of the cage member 10.
It is also possible to extend along A and the inner peripheral surface 10B at least to the drive shaft 2 side so as to communicate with the space S provided in the inner peripheral surface 3A forming bottom of the external connecting member 3 (see FIG. 1).

The space S is filled with a lubricant such as grease, and the filled lubricant is lubricated by rolling of the steel balls 5 through the first rolling groove 4 and the second rolling groove 9. It is possible to prevent the grease from running out between the steel ball 5 and the steel ball support hole 11 by guiding it to the agent holding groove 20. Further, by extending the lubricant holding groove 20 to the outer peripheral surface 10A or the inner peripheral surface 10B of the cage member 10 as described above, the lubricant can be supplied more smoothly through these grooves 20. It will be possible. The cross-sectional shape of the lubricant holding groove 20 is not limited to the V-shaped groove as shown in FIG. 3, but may be a semicircular circular groove, and the number of grooves 20 is the same as in the above embodiment. The number is not limited to.

Further, in the usual case, when the steel ball support hole 11 is bored, press working and broaching are generally carried out. However, the tool used during such working is preliminarily formed with the lubricant retaining groove as described above. By providing a possible blade mold, it is possible to suppress the cost for forming the groove.

The driving force transmission operation by the constant velocity joint 1 thus constructed is not different from that of the conventional one of this kind, and is independent of the driving shaft 2 regardless of the bending angle θ °. The driven shaft 3 and the driven shaft 3 are kept bent at a point O and rotate at a constant speed. Then, each steel ball 5 performs a turning motion about the point O on the surface T shown in FIGS. 1 and 2, and both axes 2 and 3 are 360 °.
While rotating, it makes one reciprocal movement along the first rolling groove 4 and the second rolling groove 9 by the amount corresponding to the bending angle θ °. During this time, the steel balls 5 are held in the steel ball support holes 11 of the cage member 10 in a play-free state, but when rolling, a lubricant film is formed between the steel balls 5 and the support holes 11 via the lubricant holding grooves 20. Since it is maintained, abrasion and seizure due to running out of grease can be prevented, and seizure on the inner connecting member inner peripheral surface 3A and the outer connecting member outer peripheral surface 7A of the cage member 10 itself can be prevented.

In the embodiment described above, the application example to the Barfield type constant velocity joint has been described as a suitable example, but the application of the present invention is not limited to this, and the internal connection member and the external connection member are It is needless to say that the present invention can be widely applied to constant velocity joints in which steel balls and cage members are connected to each other.

Further, although steel balls are used as the balls, the present invention is not limited to this and may be made of a material having high hardness and low rolling resistance.

[0019]

As described above, according to the present invention, since the lubricating groove for guiding the lubricant is provided on at least the sliding contact surface of the cage member, which is in sliding contact with the ball, the cage member is supported. Between the hole and the ball, between the ball and the first rolling groove and the second rolling groove, between the inner peripheral surface of the cage member and the outer peripheral surface of the internal connecting member, the inner peripheral surface of the external connecting member and the outer peripheral surface of the cage member. It is possible to maintain a good lubrication state between each of the surfaces and the surface, and especially contributes to prevention of early wear between the ball and the cage, and scratches on the first rolling groove and the second rolling groove due to damage of the ball. It is possible to prevent adverse effects such as constant velocity joints and prolong the life of the constant velocity joint itself.

Further, in forming the lubricant retaining groove in the steel ball supporting hole of the cage, it is possible to carry out it with a slight modification to the conventional machining tool, which may cause a large increase in cost. Absent.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structural example of a constant velocity joint of the present invention.

FIG. 2 is a sectional view showing a bent state by the constant velocity joint of the present invention.

FIG. 3 is an explanatory view showing a configuration of a cage member according to the present invention by a side view (A) and a view (B) taken along the line AA in (A).

[Explanation of symbols]

 1 constant velocity joint 2 drive shaft 3 external connection member 3A inner peripheral surface 4 concave curved groove (first rolling groove) 5 steel ball (ball) 6 driven shaft 7 internal connecting member 7A outer peripheral surface 8 snap ring 9 convex curved Groove (second rolling groove) 10 Cage member 10A (Cage) outer peripheral surface 10B (Cage) inner peripheral surface 11 Steel ball support hole 20 Lubricant holding groove S Space A, B, O Arc center

Claims (3)

[Claims] 1. An annular cage member slidably contacting a spherical inner peripheral surface of an external connecting member and a spherical outer peripheral surface of an internal connecting member, and a plurality of support holes provided at equal positions in the circumferential direction of the cage member. In a constant velocity joint that is rotatably fitted to and is bendably connected via balls that roll along rolling grooves provided in the external connection member and the internal connection member. A constant velocity joint characterized in that a lubricating groove for guiding a lubricant is provided on at least a sliding contact surface of the support hole with which the ball slides. 2. The constant velocity joint according to claim 1, wherein the lubricating groove is formed in a direction in which the support hole is formed. 3. The constant velocity joint according to claim 1, wherein the ball is fitted in the support hole in the cage member axial direction without play.