JP2518875Y2 - bush - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement of a bush that rotatably or reciprocally supports a shaft.

[Conventional technology]

2. Description of the Related Art Conventionally, as shown in FIG. 2, a synthetic resin is molded into an annular body having a rectangular cross section, and is fitted into an inner wall of a shaft hole (3) of a housing (2) so as to freely rotate or reciprocate the shaft (4). Bushings (1) which are movably supported are known. In many cases, this type of bush (1) is juxtaposed with the oil seal (5) and is arranged on the side opposite to the sealed fluid of the oil seal (5). The oil seal (5) has a seal lip (6) in close contact with the shaft (4), and a backup ring (7) is fitted on the back side of the seal lip (6). The backup ring (7) suppresses the deformation of the seal lip (6) so that the seal lip (6) does not excessively bend when subjected to a large sealing pressure.
It is sometimes called a "retainer" as shown in Fig. 4 and its description on the microfilm of Japanese Utility Model Application No. Sho 53-180534 (No. Sho 55-94916).

[Problems to be solved by the device]

The following problems are pointed out with respect to the above conventional techniques.
That is, when the sealing pressure is large, the pressure is transmitted to the backup ring (7) through the seal lip (6) and the backup ring (7) is largely deformed, so that a part of the backup ring (7) is formed by the bush ( The problem that the backup ring (7) is damaged or the sliding resistance due to the rotation of the shaft (4) becomes excessive due to erosion into the bearing gap (8) between the shaft (1) and the shaft (4). There is.

[Means for solving the problem]

In view of the above points, the present invention has an object to solve the problems found in the above-mentioned prior art, and in order to achieve this object, it is fixed to the inner circumference of the shaft hole of the housing and inserted into the shaft hole. A backup ring portion that supports the seal lip is provided at one axial end of an annular bearing portion that is axially aligned with an oil seal that includes a seal lip that slidably contacts the outer peripheral surface of the shaft. It was decided to integrally mold.

[Action]

The backup ring part, which is integrally molded at one axial end of the bearing part, does not erode into the bearing gap between the bearing part and the shaft even if it is deformed by a large pressure during operation, and the adverse effects caused by this It can be prevented.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the bush (1) has one axial end of a bearing portion (9) formed of synthetic resin into an annular body having a rectangular cross section. A backup ring portion (10) is integrally formed on the shaft, and the bearing (9) supports the shaft (4) rotatably or reciprocally, and the backup ring portion (10) seals a lip (6) of the oil seal (5). ) Is supported, the backup ring portion (10) is elastically deformed even if a large sealing pressure is applied during operation, and the backup ring portion (10) does not protrude between the bearing portion (9) and the shaft (4). The backup ring portion (10) has one end in the axial direction integrally connected to the bearing portion (9) and has a lip shape, and has an appropriate spring property substantially in the radial direction. Elastically supports the sealing lip (6). Further, the backup ring portion (10) does not come into full contact with the shaft (4) on the inner peripheral surface thereof even if it receives a large sealing pressure, and does not cling to the shaft (4), whereby the sliding resistance can be suppressed to be small.

[Effect of device]

As described above, the bush of the present invention is axially aligned with an oil seal fixed to the inner circumference of the shaft hole of the housing and provided with a seal lip that slidably seals the outer peripheral surface of the shaft inserted through the shaft hole. A backup ring portion that supports the seal lip is integrally formed with one end in the axial direction of an annular bearing portion that supports the shaft, and the deformation of the oil seal is suppressed so that the seal lip does not excessively bend. A backup function is provided, the number of parts can be reduced as compared with the conventional technique, and it is possible to prevent the backup ring portion from being eroded into the bearing gap even when it is deformed by receiving a large sealing pressure. Therefore, it is possible to prevent the backup ring portion from being damaged or the sliding resistance from becoming excessive due to the protrusion.

[Brief description of drawings]

FIG. 1 is a half-cut sectional view showing a mounted state of a bush according to an embodiment of the present invention, and FIG. 2 is a half-cut sectional view showing a mounted state of a bush according to a conventional technique. (1) Bush, (2) Housing, (3) Shaft hole (4) Shaft, (5) Oil seal (6) Seal lip, (7) Backup ring (8) Bearing gap, (9) Bearing part (10) Backup ring section

Claims (1)

(57) [Scope of utility model registration request] 1. A seal lip (6) fixed to an inner circumference of a shaft hole (3) of a housing (2) and slidably in contact with an outer peripheral surface of a shaft (4) inserted through the shaft hole (3). A backup ring portion (10) that supports the seal lip (6) at one axial end of an annular bearing portion (9) that supports the shaft (4) and that is axially aligned with the provided oil seal (5). A bush characterized by being integrally molded.