JP2002372131A - Bearing with resin pulley - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing with a resin pulley in which any creep can be prevented by the high bonding strength between the resin pulley and an outer ring of the bearing. SOLUTION: In the bearing with the resin pulley in which the resin pulley 1 is integrally injection-molded on an outer circumference of the outer ring 3 of the bearing 2, circumferential grooves 9 and 10 with groove extension lines inclined opposite to each other in the crossing direction outside the bearing are formed at two parts separated from each other in the axial direction of the outer circumferential surface of the outer ring 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing with a resin pulley for driving, for example, a cooling pump or a generator of an automobile,
In particular, the present invention relates to a bearing with a resin pulley that prevents creep between the outer ring of the bearing and the resin pulley.

[0002]

2. Description of the Related Art Conventionally, in a bearing with a resin pulley that drives a cooling pump or a generator of an automobile, the resin expands in an axial direction and a circumferential direction at a high temperature to cause a gap between the resin pulley and a bearing outer ring. Decrease in bonding strength, ie, creep, may be a problem. If the creep occurs, abnormal heat generation due to friction occurs, which may lead to resin melting and bearing damage.

Therefore, in order to prevent the above-mentioned problems,
Various measures have been taken. For example, as shown in FIG. 3, in a ball bearing 32 including an inner ring 34, an outer ring 33, and a ball 35 interposed between the inner and outer rings 34, 33 and held by a retainer 36, the outer ring 33 There is known a bearing with a resin pulley in which eccentric grooves 33a are formed at both ends of an outer peripheral surface and a resin pulley 31 is integrated with the outer peripheral surface of the outer ring by injection molding. In addition, as a material of this resin pulley 31,
Polyamide of nylon 66, polyacetal, or the like is used.

[0004] Further, the one described in Japanese Utility Model Laid-Open No. 58-173864 is also known. This is, as shown in FIGS. 4 and 5, an inner ring 44, an outer ring 43, and inner and outer rings 44, 4.
In the ball bearing 42 provided with a ball 45 interposed between the three and held by a cage 46 and a seal 47, the outer ring 43
An inclined circumferential groove 48 having an opening directed toward the other end is formed at one end of the outer peripheral surface of the outer ring, and a resin pulley 41 is integrated with the outer peripheral surface of the outer ring by injection molding.
In addition, as the material of the resin pulley 41, for example, the same material as that of FIG. 3 is used.

[0005]

In the conventional bearing with a resin pulley shown in FIG. 3, there is no problem at a low temperature, but at a high temperature, the resin expands in the axial direction and the circumferential direction between the resin pulley 31 and the outer ring 33. The bonding force may decrease, and creep may occur between the two.

Further, in the bearing with a resin pulley shown in FIGS. 4 and 5, if the axial pull-out force is strong when the resin expands in the axial and circumferential directions at a high temperature, the inclined circumferential groove 48 forms one end of the outer race. Since it is formed only in the portion, the bonding strength between the two may be reduced and creep may occur.

SUMMARY OF THE INVENTION The present invention addresses the above-mentioned problems, and has a high coupling strength between a resin pulley and a bearing outer ring.
It is an object of the present invention to provide a pulley with resin in which creep is prevented.

[0008]

According to a first aspect of the present invention, there is provided a bearing with a resin pulley in which a resin pulley is integrated with an outer periphery of an outer ring of the bearing by injection molding. Are formed at two locations spaced apart in the axial direction from each other so as to be inclined in directions opposite to each other in a direction in which the groove extension lines intersect outside the bearing.

Further, in the invention of claim 2, the above-mentioned 2
It is characterized in that the peripheral grooves at the locations are formed in symmetrical positions with respect to a vertical line passing through the center of the bearing.

Furthermore, in the invention of claim 3,
The angle between the two circumferential grooves and the outer peripheral surface of the outer ring is the same.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The contents of the present invention will be described with reference to FIGS. This resin pulley bearing is a ball bearing 2 provided with an outer ring 3, an inner ring 4, a ball 5 interposed between the inner and outer rings 4, 3 and held by a retainer 6, and a seal 7, the outer periphery of the outer ring 3 A resin pulley 1 having a surface provided with a groove 1a for hanging a belt (not shown) is integrated by resin molding. Reference numeral 8 denotes a rotating shaft that transmits torque from a power source such as an engine fitted and fixed to the inner ring 4. Further, as the resin material, for example, polyamide such as nylon 66, polyacetal, or the like is used as in the conventional case.

The outer peripheral surface 3a of the outer race 3 of the ball bearing 2
Peripheral grooves 9 and 10 that are inclined in opposite directions are formed at the locations. That is, the extension line Y1-Y1 of the circumferential groove 9
And the extension line Y2-Y2 of the circumferential groove 10 is inclined to intersect at a point P outside the bearing. Therefore, the angles θ1 and θ2 between the circumferential grooves 9 and 10 and the outer peripheral surface 3a of the outer race 3 are 90
Less than degrees. The circumferential grooves 9 and 10 which are opposite to each other
Due to the shape, even if the resin expands in the axial direction and the circumferential direction at a high temperature, the resin expands in opposite directions to each other.
The surface pressure on the side surface 9a on the bearing outside side and the surface pressure on the side surface 10a on the bearing outside side of the circumferential groove 10 increase. As a result, the coupling strength between the outer race 3 and the resin pulley 1 increases, and creep between the two is prevented. In consideration of the amount of resin expansion in the axial direction, that is, the surface pressure, the axial distance L between the two circumferential grooves 9 and 10 is as long as possible. It is better to form each. The groove depth from the outer peripheral surface of the outer ring 3 is also set appropriately so as to obtain an appropriate coupling strength without impairing the strength of the outer ring 3.

Further, when the two peripheral grooves 9 and 10 are formed at symmetrical positions with respect to a vertical line XX passing through the center of the bearing, the respective side surfaces 9a and 10a of the peripheral grooves 9 and 10 are formed.
Are balanced in the axial direction of the bearing, leading to a stable coupling force between the resin pulley 1 and the outer ring 3, and a further anti-creep effect can be obtained.

Further, the angles of the two circumferential grooves with respect to the outer peripheral surface of the outer ring are the same, so that the two circumferential grooves 9,
The surface pressures on the side surfaces 9a and 10a of the ten can be made substantially the same, and in this case also, the coupling force between the resin pulley 1 and the outer ring 3 is stabilized, and the creep preventing effect can be further obtained. In particular, the circumferential grooves 9 and 10 have an angle θ1,
It is preferable that θ2 is 45 degrees. It is for the following reasons. That is, when the direction of the resultant force of the axial force generated by the expansion of the resin in the axial direction and the radial force generated by the expansion of the resin in the circumferential direction is perpendicular to the side surfaces 9a and 10a, the surface pressure becomes the highest. As a result, the coupling strength between the outer ring 3 and the resin pulley 1 becomes highest. Therefore, from this point, each side 9
When the angle between a and 10a is set to 45 degrees, the resultant force is perpendicular to the side surfaces 9a and 10a, which is the most preferable.

Although a bearing with a resin pulley using a ball bearing has been described as an embodiment of the present invention, a bearing with a resin pulley using a rolling bearing such as a cylindrical roller may be used. May be used as a bearing with a resin pulley.

[0016]

According to the first aspect of the present invention, in a bearing with a resin pulley integrated with a resin pulley on the outer periphery of the outer ring of the bearing by injection molding, the groove is extended to two axially separated positions on the outer peripheral surface of the outer ring. Since the circumferential grooves are formed so that they slant in the direction in which the wires intersect outside the bearing, they will expand in the opposite directions even if the resin expands in the axial and circumferential directions at high temperatures. Thus, the surface pressure on the outer side surface of the peripheral groove in the bearing and the surface pressure on the outer side surface of the peripheral groove in the peripheral groove are increased. As a result, the coupling strength between the outer ring and the resin pulley increases, and creep between the two is prevented.

Further, in the invention of claim 2, the above-mentioned 2
Since the circumferential grooves at the locations are formed at symmetrical positions with respect to a vertical line passing through the center of the bearing, the surface pressure acting positions on the respective side surfaces of the circumferential grooves can be balanced in the axial direction of the bearing. This leads to stabilization of the coupling force between the outer rings, and a further anti-creep effect can be obtained.

Further, in the invention of claim 3,
Since the two peripheral grooves have the same angle with respect to the outer peripheral surface of the outer ring, the surface pressure on each side surface of the two peripheral grooves can be made substantially the same. , And the creep preventing effect is further obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a bearing with a resin pulley according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a waist of the outer race of FIG. 1;

FIG. 3 is a sectional view of a conventional bearing with a resin pulley.

FIG. 4 is a sectional view of another conventional bearing with a resin pulley.

FIG. 5 is an enlarged sectional view of a waist of the outer race of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin pulley 2 Ball bearing 3 Outer ring 4 Inner ring 5 Ball 6 Cage 7 Seal 8 Rotation shaft 9 Circumferential groove 10 Circumferential groove

Claims (3)

[Claims] In a bearing with a resin pulley, wherein a resin pulley is integrated with an outer periphery of an outer ring of a bearing by injection molding, a groove extension line intersects outside the bearing at two axially spaced locations on an outer peripheral surface of the outer ring. A bearing with a resin pulley, wherein circumferential grooves inclined in opposite directions to each other are formed. 2. The bearing with a resin pulley according to claim 1, wherein the two circumferential grooves are formed at left-right symmetric positions with respect to a vertical line passing through the center of the bearing. 3. The bearing with a resin pulley according to claim 1, wherein the angles of the two circumferential grooves with respect to the outer peripheral surface of the outer ring are the same.