JP2001146954A - Pulley unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten the joining strength between the inner ring of a pulley unit and a bracket. SOLUTION: The pulley unit is composed of a pulley 11, a rolling bearing 12 to support the pulley 11 rotatably, an inner ring 13 fitted integrally in the inside surface of the rolling bearing 12, and a bracket 14 coupled with the inner ring 13, wherein the bracket 14 and inner ring 13 are integrated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pulley unit, and more particularly, to a pulley unit used for an automobile engine or the like.

[0002]

2. Description of the Related Art As shown in FIG. 3, a pulley unit conventionally used for an automobile engine or the like has a pulley 1, a rolling bearing 2 for rotatably supporting the pulley 1, and an integral inner surface of the rolling bearing 2. And a bracket 4 connected to the connecting member 3. The connection between the connecting member 3 and the bracket 4 is performed by passing a protrusion provided on the connecting member 3 through a hole provided on the bracket 4 and caulking the connecting portion.

[0003]

The above connecting member 3
Since the and the bracket 4 are connected by caulking, they usually have a strong joint strength. However, since the pulley unit generates vibration, the above-described caulking may be loosened due to the vibration. This looseness causes abnormal noise of the pulley unit, and eventually lowers the strength of the pulley unit.

Accordingly, an object of the present invention is to improve the joining strength between a connecting member of a pulley unit and a bracket.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a pulley unit formed of a pulley, a rolling bearing rotatably supporting the pulley, and a bracket connected to an inner ring of the rolling bearing. Has solved the above-mentioned problem.

[0006] Since the bracket and the inner ring are integrated, the joining strength between them can be increased, and generation of abnormal noise can be suppressed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a pulley unit according to the present invention has a pulley 11, a rolling bearing 12 rotatably supporting the pulley 11, and a rolling bearing 1 as shown in FIG.
It is formed from a bracket 14 connected to the second inner ring 13. The bracket 14 has an inner surface on which an engine is mounted, and has an insertion hole 15 for a fixing bolt for fixing the engine.

The inner race 13 and the bracket 14 are connected so as to be integrated with each other. This inner ring 13 is S
It can be manufactured by forging carburized steel such as CM415, or forging or shaving from a shaft member of high carbon chrome steel such as SUJ2.

As shown in FIG. 1, the inner ring 13 has a concave portion for accommodating the head of the connecting bolt 16 or the nut 17, and forms a cup with a bottom. At this time, a rolling surface is formed on the outer peripheral surface of the inner ring 13.

As a specific connecting means between the inner ring 13 and the bracket 14, as shown in FIG. 1, a fixing bolt 16 and a nut 17 are used to connect the inner ring 13 and the bracket 1.
4 and a method of connecting them so as to be integrated by fastening them. At this time, the concave portion 2 is
When 1 is formed, the head of the fixing bolt 16 or the nut 17 can be housed in the recess 21. In this case, no protrusion is formed on the inner surface of the bracket 14, and the mounting of the engine is not affected. The bottom of the inner ring 13 is
It is more preferable that both the fixing bolt 16 and the head of the nut 17 are accommodated when the bottom of the recess 21 is brought into contact.

At this time, the bottom of the inner ring 13 and the bracket 1
A hole for loosely fitting the fixing bolt 16 is formed at the bottom of the base 4. By tightening the fixing bolt 16 and the nut 17 through this hole, the inner ring 13 and the bracket 14 can be connected so as to be integrated.

When the fixing bolt 16 is provided with a head having a wrench hole, the weight and the size can be reduced.

[0013] The bracket 14 is composed of S10C to S20.
A low carbon steel sheet of C, or a rolled steel sheet such as SPCC or SPHC is generally used, and is formed into a desired shape by press forming. Also, as described above, the bracket 14
In order to receive a moment load from a belt (not shown) on the outer periphery of the pulley 11 via the rolling bearing 12, the plate may be thickened, or may be subjected to a heat treatment such as carburizing and quenching.

For mounting the engine on the bracket 14, first, the fixing bolt is temporarily fixed to the fixing bolt insertion hole 15 with the fixing bolt. At this time, the pulley unit swings and rotates together with the bracket 14 around the fixing bolt.
A hook portion (not shown) is formed on a part of the bracket 14 to hold a tension setting coil spring or the like (not shown). The hook portion runs on the outer peripheral surface of the pulley 11 and the tension setting spring. At the position where the tension of the belt (not shown) is balanced, the fixing bolt is fastened and the bracket 1 is attached to the engine.
4 is attached. At this time, the flatness of the mounting surface of the bracket 14 to the engine, the mounting surface and the bracket 1
4 and the flatness of the bottom surface affect the inclination of the pulley, and this inclination affects whether or not a belt (not shown) running on the outer peripheral surface of the pulley 11 runs laterally. Therefore, the flatness and parallelism described above are strictly managed.

The mounting surface of the inner ring 13 of the rolling bearing 12 serves as a reference surface for grinding the rolling surface, and the flatness of the mounting surface, the perpendicularity to the hole, and the parallelism with the bottom bolt seat surface. Is managed.

As another method of connecting the inner ring 13 and the bracket 14 so as to be integrated with each other, as shown in FIG. 2, a bottomless cylindrical shape is formed on the inner ring 13 ', and the bracket 14 is pressed. The bottomed cylindrical part 22
Is formed, and the cylindrical portion 22 of the bracket 14 is inserted into the inner peripheral portion of the inner ring 13 ′. The cylindrical portion 22 allows the bracket 14 to also serve as a rotation axis. A stepped portion 23 is formed in the cylindrical portion 22 of the bracket 14.
The inner ring 13 'is sandwiched between 3 and a separate washer. By this sandwiching, the inner race 13 and the bracket 14 can be integrated.

At this time, it is preferable that the outer surface of the bottom of the cylindrical portion 22 and the one end surface of the inner ring 13 'are aligned on substantially the same plane. In this way, the fixed plate 18 that covers the bottom outer surface of the cylindrical portion 22 and is larger than the bottom outer surface is attached to the inner race 1.
3 ′, the bottom of the recess 21 and the fixing plate 1
The inner ring 13 and the bracket 14 can be further integrated by forming a hole for loosely fitting the fixing bolt 16 in the 8 and tightening the fixing bolt 16 and the nut 17 through this hole.

In this case, a standard inner ring can be used as the inner ring 13 ', which is compatible with conventional products.

[0019]

According to the present invention, since the bracket and the inner ring are integrated without connecting members, the joining strength and rigidity of the unit can be increased, and a highly accurate and highly rigid pulley unit can be obtained.

Further, since the bracket has a concave shape instead of a flat shape, the rigidity of the bracket itself is improved.

Further, if a wrench hole is provided in the head of the fixing bolt, the fixing bolt and the nut can be reduced in size, so that the burry unit can be made compact and light.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a pulley unit according to the present invention.

FIG. 2 is a sectional view showing another example of the pulley unit according to the present invention.

FIG. 3 is a sectional view showing an example of a conventional pulley unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pulley 2 Rolling bearing 3 Connecting member 4 Bracket 11 Pulley 12 Rolling bearing 13 Inner ring 14 Bracket 15 Insertion hole 16 Fixing bolt 17 Nut 18 Fixing plate 21 Recess 22 Cylindrical part 23 Stepped part

Claims (5)

[Claims] 1. A pulley unit comprising a pulley, a rolling bearing rotatably supporting the pulley, and a bracket connected to an inner ring of the rolling bearing, wherein the bracket and the inner ring are integrated. Pulley unit. 2. The pulley unit according to claim 1, wherein the bracket and the inner race are integrated by fastening with a fixing bolt and a nut. 3. The pulley unit according to claim 2, wherein a recess is formed in the bracket, and a head of the fixing bolt or the nut is housed in the recess. 4. The pulley unit according to claim 2, wherein the inner race has a cup shape with a bottom, and a hole for loosely fitting the fixing bolt is formed in the bottom portion. 5. The pulley unit according to claim 1, wherein a bottomed cylindrical portion is formed on the bracket, and the cylindrical portion is inserted into an inner ring of the rolling bearing.