JP2014109297A - Sealing device and rolling bearing unit equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device capable of improving sealing performance and reducing torque, and to provide a rolling bearing unit equipped therewith.SOLUTION: A sealing device 16 includes: a slinger 23 approximately L-shaped in cross section, fixed to an inner ring 11, and having a first cylindrical part 31 and a first annular part 32; a core metal 24 approximately L-shaped in cross section, fixed to an outer ring 13, and having a second cylindrical part 36 and a second annular part 37; and a seal section 25 having an inside seal lip 46, an intermediate seal lip 47 and an outside seal lip 48 branching from a branch portion 41b of a trunk part 41 which is anchored to the core metal 24 and extends from an end face 37a of the second annular part 37 in the approximately radial direction, and extending toward the first cylindrical part and the first annular part 32 to come in slide contact with the first cylindrical part or the first annular part throughout its periphery. The trunk part has a trunk part minimum thickness portion 41c whose thickness is minimum, between the side of the end face 37a and the side of the outside seal lip 48. The outside seal lip 48 is formed so that its thickness is gradually greater as extending from the side of the trunk part 41 toward the side of the first annular part.

Description

  The present invention relates to a sealing device and a rolling bearing unit including the sealing device.

  A rolling bearing used for a wheel support portion of a vehicle is provided with a sealing device in order to prevent foreign matter from entering from outside and leakage of lubricant from inside. Conventionally, as such a sealing device, a cored bar that is fitted and fixed to one of a rotating member and a stationary member, a sealing member that is fixed to the cored bar and made of an elastic body, and opposed to the sealing member A sealing device is known that includes a slinger fitted and fixed to the other member of the rotating member and the stationary member (see, for example, Patent Document 1).

  Specifically, as shown in FIG. 2, the sealing device 116 of Patent Document 1 includes a slinger 123 that is externally fixed to the end portion of the inner ring 111 by an interference fit, and an internal fit by an interference fit to the end portion of the outer ring 113. A fixed cored bar 124 and a seal part 125 fixed to the cored bar 124 are provided. The slinger 123 is a member having an L-shaped cross section composed of a slinger cylindrical portion 131 and a slinger annular portion 132, and the core metal 124 is also an L-shaped cross section composed of a core metal cylindrical portion 136 and a core metal annular portion 137. It is a member.

  The seal portion 125 is formed of an elastic material and has three seal lips branched from a portion fixed to the core metal ring portion 137. The three seal lips include an inner seal lip 146 and an intermediate seal lip 147 that are in sliding contact with the slinger cylindrical portion 131 of the slinger 123, and an outer seal lip 148 that is in sliding contact with the slinger annular portion 132 of the slinger 123. The bearing space is sealed by the inner seal lip 146, the intermediate seal lip 147, and the outer seal lip 148.

  Here, a minimum thickness portion 148 a is provided on the base side of the outer seal lip 148. With the minimum thickness portion 148a, the tip end portion of the outer seal lip 148 can be slid along the slinger ring portion 132 efficiently. Further, even when the tightening margin of the outer seal lip 148 changes, it is possible to suppress a change in the contact load at the front end portion of the outer seal lip 148.

JP 2005-16603 A

  However, Patent Document 1 does not describe any means for suppressing changes in the tightening allowance of the inner seal lip 146 and the intermediate seal lip 147 and changes in contact load.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sealing device and a rolling bearing unit with the sealing device capable of improving the sealing performance and reducing the torque.

The above object of the present invention can be achieved by the following constitution.
(1) A rotary device disposed concentrically and rotatably relative to each other, and a sealing device for sealing between stationary members,
A slinger having a substantially L-shaped cross section fixed to one of the rotating member and the stationary member and having a first cylindrical portion and a first annular portion;
A cored bar having a substantially L-shaped cross section fixed to the other of the rotating member and the stationary member and having a second cylindrical portion and a second annular portion;
A backbone portion fixed to the core metal and extending in a substantially radial direction from an end surface of the second annular portion, and branched from a distal end of the backbone portion toward the first cylindrical portion and the first annular portion. A plurality of seal lips that extend and slidably contact the first cylindrical portion and the first annular portion over the entire circumference, and a seal portion,
The trunk portion has a minimum thickness portion having a smallest thickness between the end face side and the seal lip side,
The sealing device, wherein the seal lip that is in sliding contact with the first annular portion is formed so that the thickness increases from the trunk portion side toward the first annular portion side.
(2) A rolling bearing unit comprising the sealing device according to (1).

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the sealing device which can improve a sealing performance, and can reduce a torque, and a rolling bearing unit with a sealing device.

It is an expanded sectional view of a 1st embodiment of a sealing device concerning the present invention. It is an expanded sectional view of the conventional sealing device.

  Hereinafter, a sealing device according to a first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the sealing device 16 of this embodiment includes a slinger 23 that is press-fitted and fixed to the outer peripheral surface 11 a of the end of the inner ring 11, and a core that is press-fitted and fixed to the inner peripheral surface 13 a of the end of the outer ring 13. A gold 24 and a seal portion 25 fixed to the core metal 24 and having three seal lips to be described later are provided.

  The slinger 23 is a member having a substantially L-shaped cross section composed of a first cylindrical portion 31 and a first annular portion 32 formed from a metal plate, and the first cylindrical portion 31 is formed on the outer peripheral surface 11 a of the end portion of the inner ring 11. By being press-fitted, the inner ring 11 is fixed.

  The metal core 24 is a member having a substantially L-shaped cross section composed of a second cylindrical portion 36 and a second annular portion 37 formed from a metal plate, and the second cylindrical portion 36 is an inner peripheral surface of an end portion of the outer ring 13. It is fixed to the outer ring 13 by being press-fitted into 13a. The slinger 23 and the cored bar 24 are disposed such that the first annular portion 32 and the second annular portion 37 are opposed to each other in the axial direction.

  The seal part 25 is formed of an elastic material such as rubber. The seal portion 25 is fixed to the core metal 24 with an adhesive or the like along the inner peripheral surface of the second annular portion 37 and the side surface of the second annular portion 37 of the core metal 24. A trunk portion 41 extending substantially in the radial direction from the end surface 37a is provided. The trunk portion 41 extends substantially linearly from the end portion 41a fixed to the end surface 37a of the second annular portion 37 to the branch portion 41b located at the tip in the substantially radial direction. Here, when the axial dimension D of the second annular portion 37 of the core metal 24 is E, the seal width between the outer peripheral surface 11a at the end of the inner ring 11 and the inner peripheral surface 13a at the end of the outer ring 13 is E. It is set so as to satisfy the relationship of 0.3 ≦ D / E ≦ 0.5.

  Three branch lips, an inner seal lip 46, an intermediate seal lip 47, and an outer seal lip 48, are integrally connected to the branch portion 41b. The inner seal lip 46 extends radially inward and axially inward from the branch portion 41 b and is in sliding contact with the first cylindrical portion 31 of the slinger 23 over the entire circumference. Further, the intermediate seal lip 47 extends radially inward and axially outward from the branch portion 41b, and is in sliding contact with the first cylindrical portion 31 of the slinger 23 over the entire circumference. Further, the outer seal lip 48 extends radially outward and axially outward from the branch portion 41b, and slidably contacts the first annular portion 32 of the slinger 23 over the entire circumference. As a result, the space between the inner ring 11 and the outer ring 13 is sealed, and entry of foreign matter from the outside and leakage of the lubricant from the inside are prevented.

  The outer seal lip 48 has a minimum thickness portion 48a in which the thickness is minimum in the vicinity of the root portion connected to the branch portion 41b of the trunk portion 41. The thickness B of the minimum thickness portion 48a is set so as to satisfy the relationship of 0.08 ≦ B / A ≦ 0.12, where A is the distance from the root portion of the outer seal lip 48 to the tip portion 48b. Is done. As described above, when the outer seal lip 48 is provided with the minimum thickness portion 48a, the outer seal lip 48 is changed when the tightening margin of the outer seal lip 48 is changed due to dimensional error, assembly error, vibration, eccentricity, or the like. 48 followability can be secured. Further, the outer seal lip 48 has a substantially increased thickness from the root portion toward the tip portion 48b, and is thicker at the portion in the vicinity of the tip portion 48b that is in sliding contact with the first annular portion 32 of the slinger 23. Has a maximum thickness portion 48c where the maximum is. The thickness C of the maximum thickness portion 48c is set so as to satisfy the relationship of C ≧ 2B with respect to the thickness B of the minimum thickness portion 48a. Thereby, the excessive deformation | transformation in the front-end | tip part 48b can be prevented, and while being able to ensure sealing performance, torque can be reduced. Moreover, since the change of the contact area between the front-end | tip part 48b and the 1st annular ring part 32 is suppressed by preventing the excessive deformation | transformation in the front-end | tip part 48b, the change of a contact load can fully be suppressed. . Further, since the rigidity of the distal end portion 48b of the outer seal lip 48 is large, the rigidity can be ensured, so that the distal end portion 48b is not greatly deformed by wear, and the sealing performance can be secured and low torque can be realized.

  Further, the trunk portion 41 has a thickness that changes from the end portion 41a toward the branch portion 41b, and has a trunk portion minimum thickness portion 41c that has the smallest thickness at a substantially intermediate portion. The thickness F of the trunk minimum thickness portion 41c is 0.06 ≦ F / E with respect to the seal width E between the outer peripheral surface 11a at the end of the inner ring 11 and the inner peripheral surface 13a at the end of the outer ring 13. It is set so as to satisfy the relationship of ≦ 0.15. This ensures follow-up of the inner seal lip 46 and the intermediate seal lip 47 when the tightening allowance of the inner seal lip 46 and the intermediate seal lip 47 changes due to dimensional errors, assembly errors, vibration, eccentricity, etc. As a result, sealing performance can be secured. Further, the contact load on the inner seal lip 46 and the intermediate seal lip 47 can be suppressed, and the torque can be reduced.

  As described above, according to the sealing device 16 of the present embodiment, the followability of the inner seal lip 46, the intermediate seal lip 47, and the outer seal lip 48 can be secured, and the inner seal lip 46, the intermediate seal lip 47, And since the change of the contact load between the outer seal lip 48 and the slinger 23 can be sufficiently suppressed, the sealing performance can be ensured and the low torque can be realized.

  In addition, this invention is not limited to embodiment mentioned above, A change, improvement, etc. are possible suitably.

16 Sealing device 23 Slinger 24 Core 25 Seal part 31 1st cylindrical part 32 1st annular part 36 2nd cylindrical part 37 2nd annular part 37a End face 41 Basic part 41a End part 41b Branch part 41c Basic part minimum thickness Part 48 outer seal lip 48a minimum thickness part 48b tip part

Claims (2)

A rotating device that is concentrically arranged and rotatable relative to each other, and a sealing device that seals between stationary members,
A slinger having a substantially L-shaped cross section fixed to one of the rotating member and the stationary member and having a first cylindrical portion and a first annular portion;
A cored bar having a substantially L-shaped cross section fixed to the other of the rotating member and the stationary member and having a second cylindrical portion and a second annular portion;
A backbone portion fixed to the core metal and extending in a substantially radial direction from an end surface of the second annular portion, and branched from a distal end of the backbone portion toward the first cylindrical portion and the first annular portion. A plurality of seal lips that extend and slidably contact the first cylindrical portion and the first annular portion over the entire circumference, and a seal portion,
The trunk portion has a minimum thickness portion having a smallest thickness between the end face side and the seal lip side,
The sealing device, wherein the seal lip that is in sliding contact with the first annular portion is formed so that the thickness increases from the trunk portion side toward the first annular portion side.   A rolling bearing unit comprising the sealing device according to claim 1.

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