JPH0654921U - Roller bearing cage - Google Patents

Abstract

(57) [Summary] [Purpose] In a cage made of resin, it is possible to secure a pocket gap in the vicinity of the gate portion and the weld portion so that smooth rotation can be performed. A pocket gap d1 between the pockets 3A and 3B near the gate portion 1a of the cage body 1 and near the weld portion 1b is made larger than the pocket gap d of another pocket 3. As a result, a necessary movable range of the rolling element 2 can be secured against molding shrinkage that tends to occur near the gate portion 1a and the weld portion 1b.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a resin-made rolling bearing cage made by injection molding.

[0002]

[Prior art]

 As shown in FIG. 6, the cage of the rolling bearing has a ring-shaped cage main body 51 provided with a large number of pockets 52 for accommodating the rolling elements. When such a cage is molded by injection molding, the gate 53 for injecting the resin material into the cavity of the molding die is made to face a part of the cage body 51 as shown in FIG. . The resin material injected from the gate 53 is divided into left and right in an annular cavity provided in the mold, flows to the opposite side, and joins and joins on the diameter line L passing through the gate 53. This joint portion is called a weld portion 51b.

[0003]

[Problems to be solved by the device]

 In the retainer injection-molded as described above, the gate portion 51a and the weld portion 51b, in which the gate 53 is arranged, have a larger molding shrinkage ratio than other portions, so that the dimension of the portion becomes smaller after molding. Roundness breaks. For example, in the one-point gate retainer shown in FIG. 6, the gate portion 51a and the weld portion 51b tend to have a shape protruding toward the inner diameter side, as emphasized in the figure. When the circularity of the retainer collapses in this way, as shown in FIG. 7, when the rolling element 54 is accommodated in the pocket 52 and is installed between the inner ring 55 and the outer ring 56, the gate portion 51a and the weld portion 51b are formed. In the pocket 52A, since the pocket width D2 portion on the outer diameter surface of the cage main body 51 approaches the inner diameter side (being closer to the center of the rolling element 54), the inner circumference of the pocket on the rolling element 52 and the outer diameter surface is There may be almost no pocket gap between them. Therefore, smooth rotation of the bearing may be hindered.

An object of the present invention is to provide a cage for rolling bearings in which pocket gaps of the entire pocket can be secured and smooth rotation can be achieved.

[0005]

[Means for Solving the Problems]

 The cage for rolling bearings according to the present invention is a resin cage having a large number of pockets for accommodating the rolling elements of the rolling bearing, and is provided between the inner surface of the pocket and the rolling element in the vicinity of the gate portion and the weld portion. The pocket gap of the pocket is larger than the pocket gap of other pockets.

[0006]

[Action]

 The mold shrinkage of the cage is larger in the vicinity of the gate and the weld than in other parts. However, as described above, the pocket gaps in the pockets near the gate and welds are set to be larger than those in other pockets in advance, so even if the circularity of the cage collapses due to molding shrinkage, it is necessary. The pocket clearance of various sizes is secured. That is, by preliminarily increasing the pocket gaps in the vicinity of the gate portion and the weld portion by the effect of mold shrinkage, the pocket gaps of the required dimensions are secured.

[0007]

【Example】

 An embodiment of the present invention will be described with reference to FIGS. This embodiment is an example applied to a cage of a ball bearing, and a large number of pockets 3 for accommodating each of the spherical rolling elements 2 are provided in a ring-shaped cage body 1 made of resin. The inner surface of each pocket 3 is formed into a spherical shape having a diameter slightly larger than that of the rolling element 2, and each pocket 3 is open on one side in the axial direction as shown in FIG. 2, and the side shape of the cage body 1 is comb-shaped. Has become.

The cage body 1 is made of an injection-molded product with a one-point gate, and the gate 4 for injecting the resin material into the cavity of the molding die has the pocket body 1 of the pocket body 1 as shown in FIGS. It is exposed to a part of the outer circumference. A portion on the diameter line L of the retainer body 1 passing through the gate 4 on the side opposite to the gate 4 is the weld portion 1b. In this embodiment, the number of pockets 3 is even, and pockets 3A and 3B are located in the gate portion 1a and the weld portion 1b, respectively.

The pockets 3A and 3B of the gate portion 1a and the weld portion 1b have the pocket inner diameter dimension D1 slightly larger than the inner diameter dimension D of each of the other pockets 3. Since each rolling element 2 has the same diameter, the gap d1 between the inner surface of the pocket in the pockets 3A and 3B of the gate portion 1a and the weld portion 1b and the rolling element 2 is larger than the gap d in the other pockets 3. Largely formed. The pocket gaps d and d1 are the difference between the pocket radius and the rolling element radius.

The operation of the above configuration will be described. Molding contraction of the retainer body 1 occurs more in the vicinity of the gate portion 1a and the weld portion 1b than in other portions. However, as described above, the pocket gap d1 between the pockets 3A and 3B of the gate portion 1a and the weld portion 1b is set to be larger than the other pocket gaps d in advance. Even if the circularity is lost, the necessary clearance between the pockets 3A, 3B and the rolling element 2 is secured even in the outer diameter portion of the cage.

That is, the extent to which the inner diameter dimension D1 of the pockets 3A and 3B is made larger than the inner diameter dimension D of the other portion is, even if there is variation in the molding shrinkage, if the molding shrinkage is within the allowable range, the outer diameter portion Make sure that the size of the pocket gap is sufficient. Although the pocket gap d1 between the gate portion 1a and the weld portion 1b may become larger than necessary, even if the gap d1 becomes large, the movable range of the rolling element 2 only widens, and the gap d1 also increases. The number of pockets for enlarging is small, so there is no practical problem.

In the above embodiment, the case where the gate portion 1a is located in the pocket 3 has been described, but the gate portion 1a may be located between the adjacent pockets 3 and 3 as shown in FIG. In that case, the pocket gaps of the pockets 3 and 3 on both sides of the gate portion 1a are made larger than those of the other pockets as described above. Even when the weld portion is located in the middle of the two pockets 3 and 3, the pocket gap is similarly increased for the two pockets on both sides of the weld portion.

Further, although the above embodiment has been described with respect to the case of being applied to the cage of the ball bearing, this idea can be applied to the cage of the roller bearing as shown in FIG. it can.

[0014]

[Effect of device]

 In the cage for rolling bearings according to the present invention, the pocket pocket gaps near the gate portion and the weld portion are set to be large in advance in consideration of the influence of molding shrinkage. A pocket gap can be secured and smooth rotation can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cutaway perspective view thereof.

FIG. 3 is a partially enlarged side view of the cage.

FIG. 4 is a partial side view of a cage according to another embodiment.

FIG. 5 is a perspective view of a cage according to still another embodiment.

FIG. 6 is a sectional view of a conventional example.

FIG. 7 is a partial cross-sectional view of a bearing incorporating the retainer.

[Explanation of symbols]

1 ... Retainer body, 1a ... Gate part, 1b ... Weld part,
2 ... rolling element, 3, 3A, 3B ... pocket, D, D1 ... pocket inner diameter, d, d1 ... pocket gap

Claims (1)

[Scope of utility model registration request] 1. A resin cage having a large number of pockets for accommodating rolling elements of a rolling bearing, wherein a pocket gap between the rolling element and the inner surface of the pocket near the gate portion and the weld portion is The cage for rolling bearings is characterized in that it is made larger than the pocket gap of the pocket.