Sealing device, and rolling bearing and hub unit incorporating the sealing unit

Abstract

A seal member with its base end connected to a metal core has three seal lips. The thickness of the tip end of the intermediate seal lip in the intermediate position is d1, and the thickness of the base end is d2. The thickness of the tip end of the innermost inner seal lip is D1 and that thickness of the base end is D2. In this case, at least part of the base end of the intermediate seal lip and inner seal lip has its thickness regulated to be 0.2·d1≦d2≦0.8·d1, and 0.5·D1≦D2<D1. The tip edge of the inner seal lip is fitted onto the outer peripheral surface of the radially inside cylindrical portion of a slinger with substantially zero interference. Consequently, even if the slinger and metal core are displaced relative to each other, excellent seal performance is secured while increase of torque is inhibited.

Description

TECHNICAL FIELD [0001] The seal assembly, the rolling bearing and the hub unit in accordance with the present invention are related, for example, to an improvement of the seal assembly for rolling bearing to be incorporated into the rotatable supporting structure of the support device etc. for the wheels of an automobile or the like. BACKGROUND OF THE INVENTION [0002] The rotatable supporting structures of various types of mechanical devices are assembled with a rolling bearing such as a ball bearing, a cylindrical roller bearing, a tapered roller bearing or the like. This kind of a rolling bearing is provided with a seal assembly for the purpose of preventing the grease applied inside of this rolling bearing from leaking out of the rolling bearing, and also preventing various types of foreign objects such as rain water, mud, dust and the like from entering the inside of the rolling bearing. FIGS. 25 to 27 show three exemplary structures of the seal assembly provided at the opening ...

AI Technical Summary

Benefits of technology

The present invention provides seal assemblies for a rolling bearing with inner and outer races. The seal assemblies include a support member, a sealing member, and an axially oriented seal lip and a radially oriented seal lip. The sealing members are fixed to the inner and outer races, and the seals are designed to prevent leakage between the races. The seals are installed in the rolling bearing to seal the outer peripheral surface of the end portion of the inner race and the inner peripheral surface of the end portion of the outer race or the member supported by the outer race. The seals are designed to have minimal interference with the movement of the parts they are in contact with and to provide a high degree of sealing. The seal assemblies can be used in various applications such as industrial machines and vehicles.

Problems solved by technology

In this manner, also in the case where the pressing force is excessively decreased, the sealing performance is degraded at the respective slidably contacting regions.

However, in this case, it becomes difficult to secure the sealing performance when the above slinger 6 moves apart from the above sealing member 7.

However, in this case, the abrasion of the tip edge of the outer seal lips 14 and 14a is even more likely to make it difficult to secure a sufficient sealing performance.

However, the provision of such another seal lip may increase the torque of the rolling bearing and substantially raise the cost of the seal assembly for the rolling bearing.

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