JPH0227696Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a tripod type constant velocity universal joint used in automobile drive shafts or propeller shafts, and in particular, the invention relates to a tripod type constant velocity universal joint used in an automobile drive shaft or a propeller shaft. It relates to a structure that smoothes the relative movement of.

BACKGROUND OF THE INVENTION Tripod type universal joints are often used in automobiles and the like because they have both constant velocity and the functions of a slip joint. In a tripod type universal joint, a tripod having three radially extending trunnions is attached to one shaft, and a spherical roller is mounted on each trunnion. A housing surrounding the tripod is attached to the other shaft, and the housing is provided with a cylindrical recess extending in the axial direction of the other shaft for accommodating the spherical roller. Torque for rotating the shafts is transmitted from one shaft to the other through the three spherical rollers. In this case, if the two axes intersect at a small angle, the spherical roller reciprocates in the cylindrical recess in the axial direction of the cylinder each time the axes rotate once. with this. The spherical roller moves relative to the trunnion in the axial direction of the trunnion, and when the spherical roller reciprocates along the recess, only one side of the spherical roller receives force due to torque transmission, so the spherical roller moves due to frictional force. rotates about the axis of the trunnion relative to the trunnion. Regarding these two types of relative motion between the spherical roller and the trunnion, it is extremely important to keep the friction loss low in order to improve the transmission efficiency of the joint.

In order to reduce the friction associated with both relative movements, U.S. Pat. The needle axes are arranged perpendicular to the trunnion axis. That is, a hollow cylindrical race member is interposed between the trunnion and the spherical roller, and groups of needles with different axial directions are provided between the trunnion and the race member and between the race member and the spherical roller. It is placed. This structure achieves the objective of reducing frictional forces by separately arranging the needles in appropriate directions for rotational and linear motions. However, hollow cylindrical races require complicated machining, especially regarding the surface that supports the needles arranged perpendicular to the trunnion axis, and the race members are made in one piece, making it difficult to create gaps for arranging the needles. , it has the disadvantage of requiring precise processing.

Problems to be Solved by the Invention Therefore, an object of the present invention is to provide a tripod type constant velocity universal joint that has low friction loss and is easy to manufacture.

Means for Solving the Problems In order to achieve this purpose, in the present invention, as in the above example, the spherical roller and the trunnion are arranged in directions suitable for rotational motion and linear motion, respectively. By providing a separate needle group to reduce friction losses, and noting that the force acting between the trunnion and the spherical roller has a nearly constant direction with respect to the trunnion, the needle group is arranged with respect to linear motion. has been streamlined, and the structure of the race member has also been simplified. That is, a plane parallel to the plane containing the trunnion axis and the axis of the shaft to which the trunnion is attached is formed on the side surface of the trunnion, a group of needles for linear motion is arranged on this plane, and the race member opposes the plane. It is divided into areas and arranged. Moreover, the unsmoothness of the rotational movement that is expected to occur due to the division of the race member in this manner is prevented by providing a thin-walled hollow cylindrical ring inside the group of rotational movement needles.

Embodiment An embodiment of the present invention will be described with reference to the drawings.
In FIG. 3, a tripod-like member 4 is spline-coupled to one shaft 1, and the member 4
are radially extending 3 arranged at equal intervals in the circumferential direction.
It has trunnions 5. Each trunnion 5
The spherical roller 6 includes a group of needles as described below,
It is mounted via a thin ring. A housing 2 is flange-coupled to the other shaft (not shown), and the housing 2 is provided with cylindrical recesses 3 extending in the axial direction of the shaft in correspondence with the three spherical rollers 6. , a spherical roller 6 is housed so as to be slidable in the axial direction of the shaft. When both shafts intersect at a small angle, as described above, each spherical roller periodically reciprocates within the cylindrical recess as the shaft rotates, and at the same time rotates and rotates against each trunnion. Perform linear motion.

1 and 2, the trunnion 5, which originally has a cylindrical shape, extends in the axial direction of the shaft 1.
Both sides of the trunnion are milled symmetrically to form two flat surfaces 12. The spherical roller 6 has a spherical outer surface and a cylindrical through hole inside. Between the trunnion 5 and the spherical roller 6,
There is a cavity corresponding to the cut portion of the trunnion, and a racer member 10 having a drawn cross section is placed in each cavity. A large number of needles 7 having the same axial direction as the shaft 1 are arranged between the flat part 12 of the trunnion 5 and the flat part of the racer member 10 facing thereto, forming a group of linear motion needles. . When the trunnion 5 and the race member 10 are combined via the needle group 7, the curved side surface of the trunnion and the curved side surface of the race surface cooperate to form one cylindrical surface. A thin hollow cylindrical thin ring 9 is placed over the outer surface of this cylindrical surface. Between the thin ring 9 and the inner wall of the cylindrical hole of the spherical roller 6, a large number of needles 8 having the same axial direction as the trunnion 5 are arranged over the entire circumference, forming a group of rotating needles. There is.
Note that the two racer members 10 and both needle groups are restrained from moving in the axial direction of the rollers with respect to the spherical rollers by a retainer 11 fixed to the spherical rollers.

The reason why the linear movement needle group is provided only along a plane parallel to the axis of the shaft 1 is that the housing 2
This is because the force acting between the shaft 1 and the spherical roller 6 has a direction substantially perpendicular to the axis of the shaft 1. The reason why the thin ring 9 is provided is that although the trunnion 5 and the race member 10 are combined to form one cylindrical surface as described above, there is a slight gap between the trunnion and the race member on the cylindrical surface. If a gap exists and a thin ring is not provided, the rotational movement needle 8 will fall into the gap during rotation of the spherical roller, impeding the smooth rotational movement of the roller and damaging the corners of the trunnion and race member. This is because it causes wear and peeling.

Effects of the invention In the invention, relative rotational motion and linear motion between the spherical roller and the trunnion,
Due to the separate needle groups, there is less wear loss in the joints.

In addition, the racer member that separates both needle groups is not made into one piece, but is divided into two parts with a drawn cross section. Machining of the fastener, racer member, and trunnion is easy, and the required processing accuracy is also lower than that of a single piece. It is more relaxed than the case.

Furthermore, by providing a thin ring, the smooth rotation of the spherical roller and the long life of the joint are guaranteed with simple parts.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of Figure 2;
The trunnion and spherical roller portion of the present invention are shown. FIG. 3 is a cross-sectional view taken perpendicular to the shaft axis, and is a schematic diagram showing the entire tripod type universal joint.

Claims (1)

[Scope of utility model registration request] In a tripod type constant velocity universal joint in which a plurality of trunnions are formed on either the driving shaft or the driven shaft and a perforated spherical roller is mounted on the trunnion, between the trunnion and the spherical roller, A needle group for rotary motion that has a plurality of needles arranged in the same axial direction as the axial direction of the trunnion, and a needle group for linear motion that has a plurality of needles arranged in the same axial direction as the axial direction of the shaft to which the trunnion is attached. a race member interposed between both needle groups and divided in the trunnion circumferential direction; and a thin cylinder interposed between the rotary movement needle group and the race member and continuous in the trunnion circumferential direction. A tripod type constant velocity universal joint characterized by having.