JPH1113770A - Sealing device for rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve rigidity without increasing the thickness of the core of a seal sheet. SOLUTION: A sealing device for a rolling bearing comprises an inner ring; an outer ring; a rolling body located between the inner and outer rings; and a seal sheet fixed at one orbit ring and sealing between the inner and outer rings by a seal part formed between the other orbit rings. The seal sheet 7 consists of a core 9 made of a metal and a rubber seal body 8 having a lip 8b forming a seal part, and soft nitriding treatment is applied on the core 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device for a rolling bearing, and more particularly to a sealing device for a rolling bearing of a crankshaft of an engine on which pressure is applied.

[0002]

2. Description of the Related Art A conventional rolling bearing sealing device includes an inner ring, an outer ring, a rolling element interposed between the inner and outer rings, and a circumferential groove formed on an inner circumferential surface at an end of the outer ring. A sealing plate having a lip forming a sealing portion between them, and a metal core is embedded in a rubber sealing body in the sealing plate to improve pressure resistance. The lip is in light contact with the side wall of the seal groove formed on the outer peripheral surface of the end of the inner ring. The contact pressure of the lip hardly changes because of a pressure-resistant structure in which an external pressure acts on the seal plate to receive the pressure, particularly at the core.

[0003]

Conventionally, when used in a part where the external pressure is relatively large, such as a crankshaft of an engine, a seal plate in the sealing device of the rolling bearing is made of a metal core and has pressure resistance. (4) The deformation of the seal plate is inevitably increased, the contact pressure of the lip against the inner ring is increased, and the problem of increased lip wear is likely to occur. Furthermore, in order to prevent the deformation of the sealing plate, the thickness of the core metal is increased.However, if the thickness is increased, the dimension of the sealing plate in the axial direction is increased by design. In some cases, the shape of the seal fitting groove of the outer ring to be fixed must be made a special shape, which makes the processing complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rolling bearing sealing device capable of improving rigidity without increasing the thickness of a core of a sealing plate.

[0005]

Means for Solving the Problems As means for solving the above-mentioned problems, an inner race, an outer race, a rolling element interposed between the inner and outer races, and one of the races fixed to one race and the other race. In a sealing device for a rolling bearing having a sealing plate that seals between inner and outer rings with a sealing portion formed therebetween, the sealing plate includes a metal core and a lip that covers the core and forms the sealing portion. And a soft nitriding treatment of the core metal.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment according to the present invention, in which a ball 4 held by a retainer 3 is interposed between an inner ring 1 and an outer ring 2. A peripheral groove 5 for fitting a seal plate 7 to be described later is formed on an inner peripheral surface 2 a of one end of the outer ring 2, and an outer peripheral surface 1 a of one end of the inner ring 1 on a side corresponding to the peripheral groove 5 of the outer ring 2 has a peripheral surface. A step 6 is formed. As shown in FIG. 2, the seal plate 7 is composed of a seal body 8 made of rubber having an outer peripheral projection 8a having a substantially triangular cross section and an inner peripheral lip 8b, an outer cylindrical portion 9a embedded in the seal body 8, and a radial flange 9b. Carbon steel plate (for example, SPCC)
And a metal core 9 having a substantially L-shaped cross section. The outer peripheral projection 8a of the seal plate 7 is press-fitted into the peripheral groove 5 of the outer ring 2 so that the seal plate 7 is fitted and fixed to the outer ring 2. Also,
The lip 8b protrudes from a side surface of the flange 9b of the metal core 9 on the inner side of the bearing, and is lightly brought into contact with the side surface 6a of the peripheral step portion 6 of the inner ring 1.

The core metal is embedded in the seal body so that a part of the flange 9b on the inner side of the bearing is exposed. Further, the material of the core metal 9 may be, for example, a stainless steel material other than the carbon steel plate. Further, the seal plate 7 includes inner and outer rings 1 and 2.
Although the case where the seal plate is disposed at one end is described, a seal plate having the same structure may be disposed at the other end of the inner and outer rings 1 and 2.

The metal core 9 is subjected to a soft nitriding treatment such as a tuftride treatment or a gas nitrocarburizing treatment in order to increase the surface hardness and improve the rigidity. Thereby, the hardness of the core metal 9 is increased only on the surface.

[0009]

As described above in detail, the stiffness can be improved without increasing the thickness of the core metal of the seal plate by subjecting the metal core of the seal plate to the soft nitriding treatment. Even when external pressure acts, the amount of deformation of the seal plate is small and the wear of the lip can be reduced, and the conventional circumferential groove for fitting the seal can be used, so that special processing of the circumferential groove for fitting the seal plate becomes unnecessary.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a rolling bearing sealing device of the present invention.

FIG. 2 is a sectional view of the seal body of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 4 Rolling element 5 Peripheral groove 6 Peripheral step part 7 Seal plate 8 Seal body 9 Core metal

Claims (1)

[Claims] An inner ring, an outer ring, a rolling element interposed between the inner and outer rings, and a sealing portion formed between the inner ring and the inner ring and a rolling element fixed to one of the ring rings and sealed between the inner and outer rings. In a sealing device for a rolling bearing having a seal plate, the seal plate is formed of a metal core and a rubber seal body having a lip that covers the core and forms the sealing portion. A sealing device for a rolling bearing, which is subjected to a soft nitriding treatment.