Assembly structure of bearing unit for mounting rotary body to engine cover and assembly method therefor

Abstract

An assembly structure of a bearing unit for mounting a rotary body to an engine cover includes a fitting hole in the engine cover for mounting a housing of the bearing unit; a counter bore in the fitting hole, substantially coaxial with a rotating shaft of the bearing unit; and sealing means sealing the counter bore. An assembly method of a bearing unit for mounting a rotary body to an engine cover includes force-fitting a housing of the bearing unit into the engine cover; fitting a rotary body or a bracket of the rotary body over a rotating shaft of the bearing unit while the rotating shaft of the bearing unit is supported by a shaft jig through a counter bore; and sealing the counter bore.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the nature and objects of the present invention, reference should be made to the following detailed description with the accompanying drawings, in which:

FIG. 1 is a view showing a timing chain cover, a bearing unit and a bracket according to an embodiment of the present invention;

FIG. 2 is a detailed view showing a fitting hole formed in the timing chain cover of FIG. 1;

FIG. 3 is a view illustrating a process of fitting the bearing unit into the timing chain cover of FIG. 1;

FIG. 4 is a view illustrating a process of fitting the bracket over the bearing unit of FIG. 1; and

FIG. 5 is a view showing the bracket fitted over a rotating shaft of the bearing unit, which is fitted into the timing chain cover of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 through 5, an assembly structure according to an exemplary embodiment of the present invention includes a fitting hole 7 formed in a timing chain cover 5, into which a housing 3 of a bearing unit 1 is fitted; a counter bore 9, which is formed in the fitting hole 7 through the-timing chain cover 5 such that the counter bore 9 is coaxial with a rotating shaft of the bearing unit 1; and a sealing means 11, which seals the counter bore 9.

In some embodiments, the sealing means 11 includes a plug bolt 13, which is screwed to the counter bore 9; and a gasket 15, which is interposed between the plug bolt 13 and the timing chain cover 5. An internal thread is formed on the counter bore 9 such that the plug bolt 13 is screwed to the counter bore 9. Furthermore, the counter bore 9 has a diameter similar to that of the rotating shaft of the bearing unit 1 for easy and removable insertion of a shaft jig J1 into the counter bore 9. The shaft jig J1 will be described in detail below.

Referring to FIG. 2, a cooling groove 17, the shape of which is depressed from the circumferential inner surface of the fitting hole 7 to thus form a surface spaced apart from the housing 3 of the bearing unit 1, is longitudinally formed in the circumferential inner surface of the fitting hole 7 in the direction in which the housing 3 of the bearing unit 1 is fitted into the fitting hole 7.

A rotary body, such as a cooling fan (not shown), may be mounted to the rotating shaft of the bearing unit 1. The fan blows air toward the timing chain cover 5, drawing air into the cooling groove 17, thus cooling the bearing unit 1.

Furthermore, a support protrusion 19 protrudes from the front surface of the timing chain cover 5 around the entrance of the fitting hole 7. The support protrusion 19 is treated by caulking while surrounding the bearing unit 1, which is fitted into the fitting hole 7.

That is, after the bearing unit 1 has been fitted into the fitting hole 7, the support protrusion 19 is formed by roller-caulking. Then, the bearing unit 1 can reliably maintain its fitted state in the fitting hole 7 without being removed from the fitting hole 7.

Referring to FIG. 3, the housing 3 of the bearing unit 1 is force fit into the fitting hole 7 using a jig J.

The fitting process is conducted by pressing the housing 3 of the bearing unit 1, and the counter bore 9 is in an open state.

The support protrusion 19 is formed by roller-caulking such that the bearing unit 1 reliably maintains its fitted state in the fitting hole 7.

Thereafter, the rotating shaft of the bearing unit 1 is supported by the shaft jig J1 through the counter bore 9. In this state, as shown in FIG. 4, a rotary body, or a bracket 21 for the rotary body, is fitted over the rotating shaft 23 of the bearing unit 1.

At this time, the timing chain cover 5 is in an unrestricted, freely movable state. Therefore, even if a fitting load is applied to the rotary body or the bracket 21 of the rotary body, no relative load is applied between the rotating shaft 23 of the bearing unit 1 and the housing 3, thus preventing the bearing unit 1 from being deformed or damaged.

Here, for example, when it is desired to support a cooling fan on the bearing unit 1, the term “rotary body” means such a cooling fan. If the cooling fan is not directly fitted over the rotating shaft 23 of the bearing unit 1 but is fitted over the rotating shaft 23 using a bracket, the bracket 21 of the rotary body is the bracket used for mounting the cooling fan.

The counter bore 9 is sealed by the plug bolt 13 and the gasket 15, which are the sealing means 11 that prevents noise from escaping and prevents oil from leaking outside the timing chain cover 5.

As is apparent from the foregoing, in the present invention, the bearing unit is prevented from being deformed or damaged during a process of mounting a bearing unit having a rotating shaft to an engine cover and a process of fitting a rotary body or a bracket for mounting the rotary body over the rotating shaft of the bearing unit mounted to the engine cover, thus reducing noise generated by the bearing unit when the rotary body rotates, and preventing the durability of the bearing unit from being reduced.

Claims

1. An assembly structure of a bearing unit for mounting a rotary body to an engine cover, comprising: a fitting hole in the engine cover for mounting a housing of the bearing unit;a counter bore in the fitting hole, substantially coaxial with a rotating shaft of the bearing unit; andsealing means sealing the counter bore.

2. The assembly structure as defined in claim 1, wherein the sealing means comprises: a plug bolt screwed into the counter bore; anda gasket between the plug bolt and the engine cover.

3. The assembly structure as defined in claim 1, further comprising a cooling groove at an inner surface of the fitting hole, depressed from the inner surface of the fitting hole to form a surface spaced apart from the housing of the bearing unit.

4. The assembly structure as defined in claim 1, further comprising a support protrusion protruding from a surface of the engine cover around an entrance of the fitting hole, the support protrusion being treated by caulking while surrounding the bearing unit.

5. An assembly method of a bearing unit for mounting a rotary body to an engine cover, comprising: force-fitting a housing of the bearing unit into the engine cover;fitting a rotary body or a bracket of the rotary body over a rotating shaft of the bearing unit while the rotating shaft of the bearing unit is supported by a shaft jig through a counter bore; andsealing the counter bore.