JP2000110842A - Rolling bearing with seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure sealing ability over a long period and to perform uniform rotation of a rotary shaft. SOLUTION: A rolling bearing 10 with a seal has a protrusion part 14 formed on an inner ring 11 and protruding toward the outer ring 12 side, and a rolling body 55 is arranged on a raceway 14a formed on the protrusion part 14. Further, seal members 57 extending toward the inner ring 11 is mounted on both sides between which the rolling body 55 of the outer ring 12 is nipped. A seal lip 57a is protruded from the tip of the seal part 57, and the seal lip is brought into contact with the side 14b of the protrusion part 14. The side 14b of the protrusion part 14 is formed on a slope having an inclination angle of 2-8 deg. with a direction extending orthogonal to the axial direction of the inner ring 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing with a seal, and more particularly, to a rolling bearing with a seal having a feature on a surface of an inner ring with which a seal lip abuts.

[0002]

2. Description of the Related Art Conventionally, in a rolling bearing, a race between an inner ring and an outer ring and a rolling element such as a ball or a roller is provided.
In order to maintain the lubrication of the raceway surface for a long period of time, a lubricant such as grease or lubricating oil is applied to the raceway surface. As one type of such rolling bearings, there is a rolling bearing with a seal provided with a sealing member for preventing leakage of a lubricant and preventing dust and dirt from adhering to a raceway surface.

FIG. 3 shows a single row deep groove ball bearing with a seal (hereinafter referred to as a rolling bearing with a seal) as an example of a rolling bearing with a seal. As shown in the drawing, the rolling bearing with seal 50 has a rolling element 55 held by a retainer 53 between an inner ring 51 and an outer ring 52. Then, on both sides of the rolling element 55 when viewed in the axial direction (left-right direction in the drawing) of the rotating shaft 60 inserted into the inner diameter surface of the inner ring 51, the outer ring 52 is provided upright on the inner diameter surface of the outer ring 52. A seal member 57 extending toward the radial surface is provided. A seal lip 57a made of an elastic material such as rubber is provided at a tip end of the seal member 57 made of rubber and the like.

[0004] The inner race 51 has a central portion of the outer diameter surface of the inner race formed on a protruding portion 54 protruding toward the outer race 52 from both ends sandwiching the central portion.
a is formed and the rolling elements 55 are arranged. Further, at positions adjacent to both sides of the protruding portion 54, concave grooves 56 are provided which are recessed radially inward of the inner ring from both ends of the outer diameter surface of the inner ring 51. Some small rolling bearings do not have such a groove 56.

In the rolling bearing 50 with seal shown in FIG. 3, the seal lip 57a is
Is in contact with Conventionally, the side surface 54b of the protruding portion 54 is formed as an inclined surface inclined at an inclination angle S with respect to a direction (vertical direction in the drawing) orthogonal to the axial direction of the inner race 51. The inclination angle S was set to about 30 ° so that chips were easily discharged when the side surface 54b was formed by cutting.

[0006]

However, when the inclination angle S of the side surface 54b is set to about 30 ° as in the rolling bearing with seal 50 shown in FIG. 3, the contact area where the seal lip 57a contacts the side surface 54b. And the sealing property tends to decrease. Also, the seal lip 57
If the contact area of the inner ring 51 is small, the inner ring 51 slides against the seal lip 57a due to rotation of the rotating shaft 60 or the like.
The load torque received from the seal lip 57a tends to be affected by the shape error of the seal lip 57a and the like, and the load torque applied to the outer periphery of the inner ring 51 tends to vary. When the load torque becomes non-uniform, uniform rotation of the rotating shaft 60 and the like is hindered. In order to solve these problems, the seal lip 57a is
It is conceivable that the seal lip 57a is extended, but it is not preferable to lengthen the seal lip 57a because the possibility that the seal lip is damaged increases.

[0007]

As a result of intensive studies, the present inventor has found that setting the inclination angle S within a specific range can solve the above-mentioned problems. That is, the rolling bearing with a seal of the present invention, on the outer diameter surface of the inner ring,
A protruding portion protruding toward the outer ring side is formed, a rolling element is disposed on a track formed on the protruding section, and seal members extending toward the inner ring are mounted on both sides of the outer ring with the rolling element therebetween. In a rolling bearing with a seal in which a seal lip at a tip of the seal member abuts a side surface of the protrusion, the side surface of the protrusion has an inclination angle of 2 to 8 ° with respect to a direction orthogonal to the axial direction of the inner ring. It is characterized by being formed on a certain inclined surface.

Here, the inclination angle is 2 to 8 °, preferably 2
-5 °, particularly preferably 2-3 °. If the inclination angle is less than 2 °, chips are difficult to be discharged when forming the side surface of the protruding portion by cutting, chatter vibration occurs, and chips are welded to the cut surface. ,
Machinability is significantly reduced. On the other hand, if the inclination angle exceeds 8 °, the cutting work is facilitated, but the above-described problem occurs. According to the rolling bearing with a seal configured as described above, the sealing performance can be ensured for a long period, and the rotating shaft and the like can be uniformly rotated. In the cutting process, the workability does not decrease so much as to cause a problem.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, about the member already demonstrated, the description is simplified or abbreviate | omitted by attaching | subjecting the same code | symbol in a figure, or an equivalent code | symbol.

FIG. 1 shows a rolling bearing with a seal according to an embodiment of the present invention. Inner ring 11 of rolling bearing 10 with seal
Is formed on a protruding portion 14 in which a center portion of the outer surface of the inner ring protrudes toward the outer ring 12 from both ends sandwiching the center portion, and a rolling element 5a is formed on a track 14a formed on the protruding portion 14.
5 are arranged. Further, at positions adjacent to both sides of the protruding portion 14, concave grooves 16 are provided which are recessed radially inward of the inner race from both ends of the outer diameter surface of the inner race 11.

The side surface 14b of the protruding portion 14 is formed as an inclined surface inclined at an inclination angle S with respect to a direction perpendicular to the axial direction of the inner race 11 (vertical direction in the drawing). S is set to 2 to 8 °.

The material of the bearing can be appropriately selected in accordance with the application in addition to the bearing steel. Seal lip 5
As the material of 7a, NBR (synthetic rubber) or the like is used, but it is not particularly limited, and fluorine rubber or the like is appropriately selected depending on the application.

FIG. 2 shows that the inner ring 11 has a protrusion 14 and a groove 1.
6 shows a state when forming No. 6 by cutting. As shown in the figure, the projecting portion 14 and the concave groove 16 are
As a result, the inner ring 11 is formed at the same time by cutting the end portion of the outer diameter surface. The forming tool 30 is attached to the side surface 14 of the protrusion 14.
b and a convex portion 31 for cutting the concave groove 16. The side surface 31a of the projection 31 is formed on the same inclined surface as the side surface 14b so that the side surface 14b of the projection 14 can be formed.

Ideally, the inclination angle S is set to 0 °. However, in such a case, it becomes difficult to discharge chips from between the forming tool 30 and the inner ring 11, thereby generating chattering vibration or discharging. Uncut chips are deposited on the side surface 14b, which is the cutting surface. If the inclination angle S is 2 to 8 ° as in the present embodiment, such a processing problem does not occur.

Rolling bearing with seal 1 having the above structure
At 0, the seal lip 57a can be reliably brought into contact with the side surface 14b by setting the inclination angle S of the side surface 14b of the protrusion 14 to 2 to 8 °. Therefore, it is possible to obtain a sufficient contact area necessary for ensuring the sealing performance. In addition, the load torque applied to the outer periphery of the inner ring 11 does not vary, and the rotating shaft 60 and the like can be uniformly rotated.

The present invention is not limited to the above-described embodiment, and appropriate modifications and changes can be made. For example, in the above-described embodiment, the concave grooves 16 are formed on both sides of the protruding portion 14. However, the technical idea of the present invention is applied to a small-sized sealed bearing having no such concave grooves. May be.

[0017]

As described above, in the rolling bearing with seal of the present invention, the side surface of the protruding portion of the inner ring is formed with an inclined surface having an inclination angle of 2 to 8 degrees with respect to a direction perpendicular to the axial direction of the inner ring. Have been. Therefore, since the seal lip can be brought into close contact with the side surface, it is possible to ensure the sealing performance over a long period of time, and it is possible to uniformly rotate the rotating shaft and the like. And workability does not decrease so much as to cause a problem.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a state when the inner ring shown in FIG. 1 is formed by cutting.

FIG. 3 is a view showing a conventional rolling bearing with a seal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Rolling bearing with a seal 11 Inner ring 12 Outer ring 14 Projection part 14a Tip surface of a projection part 14b Side surface of a projection part 16 Concave groove S Inclined angle 53 Cage 55 Roller 57 Seal member 57a Seal lip

Claims (1)

[Claims] 1. A projection projecting toward an outer ring is formed on an outer diameter surface of an inner ring, and rolling elements are arranged on a track formed on the projection, and both sides of the outer ring sandwiching the rolling element. A seal member extending toward the inner ring is attached to the
In a rolling bearing with a seal in which a seal lip at a tip of the seal member abuts on a side surface of the protrusion, a side surface of the protrusion has an inclination angle of 2 to 8 ° with respect to a direction orthogonal to an axial direction of the inner ring. A rolling bearing with a seal formed on a surface.