JPH0734253U - Pulley - Google Patents

Abstract

(57) [Summary] [Purpose] To use a rolling bearing that meets the general specifications, but not to deform the outer ring of the rolling bearing during insert molding of the pulley body made of synthetic resin. [Structure] A rolling bearing 2, a thick metal ring 3 press-fitted onto an outer ring of the rolling bearing 2, and a pulley body 4 made of synthetic resin insert-molded on the outer periphery of the ring 3.
And a pulley with. By interposing the thick ring 3 between the rolling bearing 2 and the pulley main body 4, the pressure of the synthetic resin material injected at the time of insert molding of the pulley main body 4 is absorbed by the ring 3, so that the rolling is performed. Unbalanced load does not act on the bearing 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pulley mainly used in a belt transmission system (a belt transmission system between a crank shaft and an auxiliary machine) around an engine of an automobile.

[0002]

[Prior art]

 In this type of conventional pulley, a synthetic resin pulley body is integrally formed on the outer circumference of the rolling bearing by insert molding.

[0003]

[Problems to be solved by the device]

 Generally, when the pulley main body is formed by insert molding, the molten synthetic resin material is injected from multiple injection gates provided in the insert mold, but the injection gates are arranged at several circumferential positions. In addition, since the pressure of the injected synthetic resin material is applied non-uniformly in the circumferential direction to the outer ring of the rolling bearing loaded in the insert mold, the outer ring is distorted and the circularity of the inner raceway surface is reduced. You will go crazy. This makes it impossible to achieve the performance and life as designed, such as the noise of rolling bearings becoming loud and premature peeling.

Although such a problem can be avoided by setting the thickness of the outer ring of the rolling bearing to be thicker than that of the general standard product, it is necessary to manufacture a dedicated rolling bearing that does not meet the general standard. Since rolling bearings within the general specifications cannot be used, the total cost must be increased.

In view of such circumstances, the present invention has an object to provide a structure that does not deform the outer ring raceway of the rolling bearing during insert molding of the pulley body made of synthetic resin, while using the rolling bearing within the general standard. I am trying.

[0006]

Means for Solving the Problems A pulley of the present invention comprises a rolling bearing, a thick metal ring that is press-fitted onto an outer ring of the rolling bearing, and a synthetic resin insert-molded around the outer periphery of the ring. It is equipped with the main body of.

[0007]

[Action]

 According to the present invention, when the pulley body is insert-molded, a metal ring is press-fitted onto the outer ring of the rolling bearing in the insert mold, and the molten synthetic resin material can be injected. Therefore, the pressure of the injected synthetic resin material is applied non-uniformly in the circumferential direction to the metal ring, but since the metal ring is thick, it does not adversely affect its inner peripheral surface such as deformation. Therefore, the unbalanced load does not act on the outer ring of the rolling bearing on the inner peripheral side.

As described above, the rolling bearing within the general standard can be used only by using the thick metal ring, which can contribute to the reduction of the total cost.

[0009]

【Example】

 Hereinafter, details of the present invention will be described based on an embodiment shown in FIGS. 1 to 3 relate to the first embodiment, FIG. 1 is a cross-sectional view taken along line (1)-(1) of FIG. 2, FIG. 2 is a front view of a pulley, and FIG. 3 is a pulley insert molding process. It is a schematic diagram showing the situation of.

In the figure, 1 indicates the entire pulley, 2 is a rolling bearing such as a deep groove type ball bearing, 3 is a metal ring, and 4 is a synthetic resin pulley body.

The rolling bearing 2 is made of a general standard product, and the inner and outer rings and rolling elements are made of steel. Although the cage is omitted in the drawing, a crown type, a machined type or a corrugated type cage may be used, or a full ball bearing structure without a cage may be used.

The metal ring 3 has a star-shaped outer shape in which projections are provided at six places on the circumference, and for example, when the inner diameter is 17 mm, the thickness of the protruding portion is 12 mm. The valley portion is made of thick-walled steel material having a thickness dimension of 6 mm. In short, the thickness of the ring 3 may be set so that the inner peripheral side is not distorted even when an unbalanced load is applied to the outer peripheral surface. Since the inner peripheral surface of the ring 3 serves as a press-fitting fitting surface for the outer ring of the rolling bearing 2, highly precise machining such as polishing is not required, and machining with appropriate precision such as grinding may be performed.

The pulley body 4 made of synthetic resin has an inner peripheral surface formed in a shape corresponding to the outer peripheral surface of the ring 3, and is provided with a peripheral groove 4 a serving as a belt transfer surface on the outer diameter portion, and The diametrical portion is provided with a diametrically inward flange 4b that covers a part of both axial side surfaces of the ring 3. The pulley main body 4 is made of a material in which reinforcing fibers (glass fibers) are mixed in an injection-moldable thermoplastic synthetic resin such as polyamide resin or polyacetal resin.

In such a pulley 1, the rolling bearing 2 and the ring 3 are prevented from rotating by press fitting, and the ring 3 and the pulley body 4 are prevented from rotating by forming a fitting shape in which they are caught in the circumferential direction. ing.

Next, a procedure for assembling the pulley 1 will be described. First, the ring 3 is press-fitted onto the outer ring of the rolling bearing 2 which is a standard product. The fitting interference at this time is such that the outer ring of the rolling bearing 2 is not significantly distorted. As shown in FIG. 3, this is positioned and loaded in the insert mold 5. At this time, the protruding portion of the star-shaped ring 3 is arranged between the injection gates 5a adjacent to each other in the circumferential direction in the plurality of injection gates 5a provided in the insert mold 5. Then, the molten synthetic resin material is injected from the plurality of injection gates 5a and hardened. In this injection process, the synthetic resin material injected from the injection gate 5a is made into a turbulent flow by the protrusions of the star-shaped ring 3, and the direction of the reinforcing fibers mixed in the synthetic resin material is disturbed, so that the so-called orientation Will be able to prevent the occurrence of. Therefore, properties such as strength and expansion coefficient of the synthetic resin forming the pulley 1 can be made uniform in all directions.

Moreover, when the synthetic resin material is injected, the pressure of the injected synthetic resin material is applied to the ring 3 in a non-uniform manner in the circumferential direction, but since the ring 3 is thick, there is a bad influence such as deformation. It is not necessary to receive it, and it is possible to prevent an unbalanced load from acting on the outer ring of the rolling bearing 2 on the inner peripheral side. Therefore, even if the rolling bearing 2 which is a general standard product is used, the roundness of the outer ring raceway is not deteriorated, noise and premature peeling do not occur, and the performance and life as designed can be achieved.

The present invention is not limited to the above embodiment. In the above embodiment, the ring 3 is in the shape of a hexagonal star, but the shape is not particularly limited. Furthermore, as for the rotation stopper between the ring 3 and the pulley body 4, as shown in FIG. 4, for example, the outer and inner circumferences of the ring 3 are concentric circles, and the outer peripheral surface is simply roughened, or a knurled pattern is formed. Concavities and convexities may be formed, and as shown in FIG. 5, the outer circumference of the ring 3 is a circle, and the axis O ₂ of its inner hole is eccentric with respect to the axis O ₁ of the rolling bearing 2. You may allow it. In addition, although not shown, the outer circumference and the inner circumference of the ring 3 may be concentric circles, and an eccentric groove may be provided on the outer peripheral surface of the ring 3 so as to be eccentric with respect to the axis O ₁ of the rolling bearing 2.

Further, in the above embodiment, the pulley body 4 is injection-molded after the ring 3 is press-fitted into the outer ring of the rolling bearing 2. However, instead of this, after the pulley body 4 is injection-molded beforehand on the ring 3, This unit may be press-fitted to the outer ring of the rolling bearing 2. In this case, the wall thickness of the ring 3 can be made thinner than that in the above-mentioned embodiment. It is desirable that this thickness be such that a sufficient press-fitting margin can be obtained and a reliable anti-rotation effect for the outer ring can be expected. Even if the inner peripheral surface is slightly distorted during injection molding by making the thickness of the ring 3 thin, it is offset as a press-fitting margin when press-fitting to the outer ring, so that the pulley 1 can be made lighter and smaller. Furthermore, although a thermoplastic synthetic resin is used as the synthetic resin in the above embodiments, a thermosetting synthetic resin such as a phenol resin may be used.

[0019]

EFFECTS OF THE INVENTION In the present invention, by using a thick metal ring, the pressure of the synthetic resin material injected during insert molding of the synthetic resin pulley body is prevented from acting as an eccentric load on the rolling bearing. Therefore, it is possible to prevent the outer ring of the rolling bearing from being deformed, and as a result, it becomes possible to use the rolling bearing within the general specifications, and it is possible to reduce the total cost.

[Brief description of drawings]

1 is a first embodiment of the pulley of the present invention, which is shown in FIG.
-A sectional view taken along line (1).

FIG. 2 is a front view of the pulley.

FIG. 3 is a schematic diagram showing a situation at the time of insert molding of the pulley.

FIG. 4 is a front view of a second embodiment of the pulley of the present invention.

FIG. 5 is a front view of a third embodiment of the pulley of the present invention.

[Explanation of symbols]

 1 Pulley 2 Rolling bearing 3 Ring 4 Pulley body

Claims (1)

[Scope of utility model registration request] 1. A rolling bearing, a thick metal ring that is press-fitted onto an outer ring of the rolling bearing, and a pulley main body made of synthetic resin that is insert-molded on the outer periphery of the ring. A pulley characterized by.