JPH011677A - Non-contact sealing device for bearings - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a non-contact type sealing device for a bearing that is incorporated into a support hole of a casing, for example, a bicycle frame, via an intermediate bushing or the like.

[Conventional technology]

An angular contact ball bearing is already known from German Utility Model Registration No. 85 31 659, which is installed in a support bore of a housing via an intermediate bushing. The sealing of this known bearing is achieved by a flange of the intermediate bushing, which extends close to the outer circumference of the shaft.

[Problem to be solved by the invention]

However, this sealing device is not sufficient in many applications, especially when splashing water.

It is an object of the invention to provide a sealing device of the type mentioned at the outset, which seals well against splashing water and dirt and has very low friction between rotating and non-rotating parts. It is in.

[Means to solve the problem]

According to the invention, this object is such that the radially extending flange of the sealing element provided in the space between the shaft etc. and the intermediate bushing has a radial and axial clearance in the annular recess of the intermediate bushing etc. This is achieved by placing the axially extending portion of the sealing element on the shaft or the like with radial contact pressure.

Furthermore, the sealing element has at the free end of the axially extending portion a small flange that projects radially outwardly;
The flange may be configured to engage the inner radial surface of the intermediate bushing with an axial clearance in the assembled state.

Preferably, the flange of such a sealing element has an inclined surface at its free end.

The sealing element as described above has an annular recess formed in the inner circumferential surface of the axially extending part, the flange having an axially inwardly bent part at the free end; More preferably, the portion is arranged to fit into an annular recess of the intermediate bushing.

[Effect]

As a result of the rotation of the sealing element with the shaft, it produces a centrifugal disc action which increases the sealing of the labyrinth seal in the area of the flange.

Furthermore, if the sealing element has a small flange at the free end of the axially extending portion that engages with the inner radial surface of the intermediate bushing in the assembled state, the sealing element may be lost due to falling off, etc. It is unitized into an intermediate bush without any. In this case, when the flange has an inclined surface, the sealing element is guided by the inclined surface and receives deformation pressure when the sealing element is assembled into the intermediate bushing, so that it is elastically deformed and enters the intermediate bushing.

Furthermore, if an annular recess is formed in the circumferential surface of the axially extending portion of the sealing element, the force required for fitting the sealing element onto the shaft is reduced.

The labyrinth seal is also improved if the sealing flange of the sealing element is provided with a bent section at its free end, which fits into the annular recess of the intermediate bushing.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

The drawing shows a bearing for a pedal crankshaft of a bicycle, which is installed in a support hole of a frame 1, indicated by a dash-dot line. This bearing consists of a shaft 2 and a double-row ball bearing 3, the balls 4 of which rotate on the raceway surface 5 of the shaft 2 and the outer ring 6. The ball 4 is guided and held by a snap retainer 7.

The side rings of the retainer 7 are provided with radially inwardly and outwardly projecting flanges 8. This flange 8 is the shaft 2
It reaches close to the outer circumferential surface 9 of the bearing and the inner circumferential surface 10 of the outer ring 6, and seals the internal chamber of the bearing. Between the frame 1 and the outer ring 6, two intermediate bushings 11.11 made of synthetic resin, for example, are provided on both axial ends.

These intermediate bushings 11 surround the large diameter part 12 of the outer ring 6 and are press-fitted or screwed into the support bore 13 of the frame 1. The intermediate bushing 11 has a T-shaped cross section, and an annular recess 15 is formed in the outer end surface 14.

In that case, the inner diameter of the bore 16 of the intermediate bushing 11 is larger than the outer diameter 9 of the shaft 2.

A sealing element 1 is provided in the space between the shaft 2 and the intermediate bushing 11 in both axial bones so as to substantially fill the space.
7 are arranged. These sealing elements 17 consist of bushings, for example made of synthetic resin, which are L-shaped in cross section and have a radially outwardly extending flange 18.
is inserted into the annular recess 15 of the intermediate bush 11.

In this case, the sealing element 17 is formed in such a way that a labyrinth gap 19 is created between it and the intermediate bushing 1, which labyrinth gap 19 provides a good sealing of the bearing. In order to position the sealing element 17 axially relative to the intermediate bushing 11, the sealing element 17 has a small radially outwardly directed flange 20 at the free end of its axially extending section. This flange 2
0 has an inclined surface 21 on the side of the ball 4, so that the sealing element 17 is pushed into the hole 16 of the intermediate bushing 11 by elastically deforming the flange 20, and in the assembled state has an axial clearance. It comes to face the inner radial surface 22 of the intermediate bushing 11 and engages with said inner radial surface 22 when subjected to an axial force. Seal element 17
is arranged on the shaft 2 with a radial contact pressure in its axially extending part and rotates with the shaft 2. Thus, by means of the flange 18 of the rotating sealing element 17,
Creates a centrifugal disc effect that prevents dirt and water from entering.

Further, in order to prevent the push-in pressure necessary for fitting the seal element 17 onto the shaft 2 from becoming too large, an annular recess 23 is provided in the inner peripheral surface of the seal element 17.

The embodiment described above is only one example of a sealing device according to the invention. The structure of the individual parts can be easily modified within the scope of the invention. For example, the free end of the flange 18 enters a corresponding recess 25 in the intermediate bushing 11.
By providing the portion 24 bent radially inward, the labyrinth sealing effect can be further improved.

〔Effect of the invention〕

As described above, the present invention provides an extremely good labyrinth seal, so that even if there is sewage splashed outside, it will not enter the bearing, and the sealing element for this purpose has a simple structure. It is also easy to install and has the advantage of improved performance and handling.

BRIEF DESCRIPTION OF THE DRAWINGS The drawing is a sectional view of a non-contact sealing device for a bearing, which is shown as an embodiment of the present invention. 1... Frame 2... Axis 11... Intermediate bushing 15... Recess 17... ...... Seal element 18 ...... Flange 20 ...... Flange 21 ...... Slanted surface 22 ...... ...Inner radial surface 23...
......Annular recess 24...A portion 25 bent inward in the axial direction...Annular recess

Claims (5)

[Claims] (1) In a non-contact sealing device for a bearing that is installed in a support hole of a casing, for example, a bicycle frame, via an intermediate bushing, etc., the sealing device is installed in the space between the shaft (2) etc. and the intermediate bushing (11). The sealed sealing element (17) has a radially extending flange (18) fitted into an annular recess (such as an intermediate bushing (11)).
15, 25) with gaps in the radial and axial directions, and the axially extending portion is placed on the shaft (2) etc. with radial contact pressure. Non-contact sealing device. (2) The sealing element (17) has a small flange (20
), and the flange (20) is formed to engage with the inner radial surface (22) of the intermediate bush (11) with an axial clearance in the assembled state. Non-contact sealing device for bearings. (3) Claim (2), wherein the flange (20) of the sealing element (17) has an inclined surface (21) at its free end.
A non-contact sealing device for the bearing described. (4) According to any one of claims (1) to (3), the sealing element (17) has an annular recess (23) formed in the inner circumferential surface of the axially extending portion. Non-contact sealing device for bearings. (5) The flange (18) has a portion (24) bent axially inward at its free end, and is arranged so that this portion (24) fits into the annular recess (25) of the intermediate bush (17). Claims (1) to (4)
A non-contact sealing device for a bearing according to any one of the above.