JP2016070306A - Sealed roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed roller bearing showing a superior anti-slurry characteristic and having an axial compact size.SOLUTION: This invention enables an entire axial size of a bearing to be compact by an arrangement in which a seal part of an inner seal 6 extending from an outer ring 2 toward an inner ring 1 is inclined toward a base end side, a location (a fitting surface 1b) where an outer seal 7 at an outer peripheral surface of the inner ring 1 is attached is arranged at more inside of a bearing space 5 than that of a seal type rolling bearing having the prior art double seal structure, the seal part of an outer seal 7 is applied as one forming a labyrinth gap 9 extending relatively long along a radial direction between it and the outer surface of the seal part of the inner seal 6 along a radial direction, the inner peripheral surface of the outer ring 2 does not require any labyrinth gap forming surface that forms a labyrinth gap between it and the seal part of the outer seal 7, width sizes of the inner ring 1 and the outer ring 2 are made smaller than that of the seal type rolling bearing having the prior art double seal structure while assuring a superior anti-slurry characteristic.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sealed type rolling bearing having a double seal structure in which a bearing space between inner and outer races (inner ring and outer ring) is sealed with two inner and outer seals in the axial direction.

  Rolling bearings used in harsh environments subject to splashes such as muddy water, for example, located in the under-floor part of an automobile and supporting a drive shaft connection part divided into a plurality of parts and a propeller shaft connection part divided into a plurality of parts In order to prevent foreign matter such as muddy water from entering the bearing space between the inner ring and the outer ring, the bearing space is sealed with two inner and outer seals in the intermediate bearing (so-called center bearing). Sealed rolling bearings with a double seal structure are often used.

  The above-mentioned double-sealed sealed rolling bearings include those in which both the inner seal and the outer seal are contact seals, and the inner seal is a contact seal and the outer seal is a non-contact slinger (for example, (See Patent Document 1). Among them, an example in which the outer seal is not contacted is shown in FIG. In the rolling bearing shown in FIG. 4, a ball 53 is held by a cage 54 between an inner ring 51 and an outer ring 52, and a bearing space 55 between the inner and outer rings 51, 52 is axially sealed inside 56 and outside seal. The inner seal 56 is fitted in the fitting groove 52a on the inner periphery of the outer ring 52, and the seal lip 56a formed of an elastic member such as a rubber material is attached to the sliding contact surface on the outer periphery of the inner ring 51. The outer seal 57 that is brought into sliding contact with 51a is fitted to the fitting surface 51b on the outer periphery of the inner ring 51 to form a labyrinth gap 58 with the inner peripheral surface of the outer ring 52.

Japanese Utility Model Publication 2-93571

  By the way, among the above-mentioned double-sealed sealed rolling bearings, both the inner and outer seals are contact seals, and usually one of the inner and outer seals is fitted to the outer ring and the other is fitted to the inner ring. Therefore, the sliding contact surface of the inner ring that is in sliding contact with the seal lip of one seal and the sliding contact surface of the outer ring that is in sliding contact with the sealing lip of the other seal must be provided so as to be aligned in the axial direction. There is a problem that it is difficult to make the entire bearing compact in the axial direction because the ring width dimension (axial dimension) becomes large.

  Even if the inner seal of the double seal structure is a contact seal and the outer seal is not contacted, for example, as shown in FIG. 4, the inner ring 51 has an inner cylindrical portion (fitting portion) of the outer seal 57. The labyrinth forming surface 52b that forms the labyrinth gap 58 between the outer ring 52 and the outer peripheral cylindrical portion 57b of the outer seal 57 is in sliding contact with the seal lip 56a of the inner seal 56, respectively. Since it is necessary to provide the inner ring 51 on the outer side in the axial direction than the sliding contact surface 51a, the width of the inner and outer rings 51 and 52 becomes large, and it is difficult to make the entire bearing axially compact.

  On the other hand, in Japanese Patent Application Laid-Open No. 2008-281072, the inner periphery of one seal fixed to the inner peripheral surface of the outer ring as a rolling bearing capable of simultaneously improving grease leakage resistance and dust resistance and space saving. The part is provided with a main lip extending radially inward and a sub lip extending axially inward, and the main lip serves as a contact seal slidably contacting the outer groove wall of the seal groove formed on the outer peripheral surface of the inner ring, and the tip of the sub lip The thing which formed the labyrinth clearance gap between the part and the inner side groove wall of the seal groove is proposed.

  In the rolling bearing proposed in Japanese Patent Application Laid-Open No. 2008-281072, the number of seals is small as compared with a sealed rolling bearing having a double seal structure, so that space saving, that is, axial compactness is possible. However, the secondary lip of the seal extends inward in the axial direction and is opposed to the inner groove wall of the seal groove on the outer peripheral surface of the inner ring at the front end portion, and a labyrinth gap formed between the front end portion of the secondary lip and the seal groove. When the main lip is deformed by mud contained in the muddy water, it passes between the main lip and the outer groove wall of the seal groove when used in an environment where muddy water is scattered. There is a risk that it will not be possible to prevent the incoming muddy water from entering the bearing.

  Accordingly, an object of the present invention is to provide a sealed rolling bearing that is excellent in mud water resistance and is compact in the axial direction.

  In order to solve the above-described problems, the present invention provides a sealed type rolling bearing having a double seal structure in which a bearing space between inner and outer races (inner and outer rings) is sealed with two inner and outer seals in the axial direction. The inner seal is composed of a fitting portion fitted to one of the two race rings, and a seal portion extending from one end of the fitting portion toward the other race ring, It is assumed that at least a part of the base end side of the seal portion is inclined in a direction in which the tip of the seal portion approaches the axial center of the bearing space, and the outer seal is fitted to the other race ring. A labyrinth gap formed between the joint portion and a seal portion extending from one end of the fitting portion toward the one raceway, and between the seal portion and the outer surface of the seal portion of the inner seal; The configuration was adopted.

  According to the above configuration, the seal portion of the inner seal is closer to the axial center of the bearing space than the sealed roller bearing having the conventional double seal structure in the vicinity of the other race ring. Since the part to be attached is provided inside the bearing space more than before, the seal part of the outer seal forms a labyrinth gap extending along the radial direction between the outer surface of the seal part of the inner seal. Thus, it is not necessary to provide a labyrinth forming surface that forms a labyrinth gap with the seal portion of the outer seal on one of the race rings. As a result, the width of both race rings can be made smaller than the conventional rolling bearing having a double seal structure while ensuring good mud water resistance, and the entire bearing can be made compact in the axial direction.

  Here, the inner seal may be a contact seal whose seal portion is in sliding contact with the other race ring, and the outer seal may be a non-contact slinger with the one race ring. At this time, the inner seal may be formed by vulcanizing a rubber material on the whole or a part of the core metal, or may be formed entirely of a synthetic resin. On the other hand, the outer seal may be formed of metal or synthetic resin.

  The above-described sealed rolling bearing according to the present invention is particularly effective as an intermediate bearing that supports a connection portion of a drive shaft of an automobile divided into a plurality of parts or an intermediate bearing that supports a connection portion of a propeller shaft of an automobile divided into a plurality of parts. Can be used.

  As described above, the sealed type rolling bearing of the present invention is configured such that the seal portion of the inner seal extending from one side of the inner and outer races toward the other side is inclined on the base end side, and the seal portion of the outer seal is the seal portion of the inner seal. Since a labyrinth gap extending along the radial direction is formed between the outer surface and the outer side surface, it can be made compact in the axial direction while ensuring good mud water resistance.

Longitudinal sectional view of the main part of the sealed rolling bearing of the embodiment FIG. 1 is an enlarged sectional view of the vicinity of the inner seal and the outer seal of the sealed rolling bearing of FIG. The state which used the sealed type rolling bearing of embodiment as an intermediate bearing which supports the connection part of the drive shaft of the vehicle divided | segmented into several or the intermediate part which supports the connection part of the propeller shaft of the vehicle divided | segmented into several is shown Longitudinal section Longitudinal sectional view of the main part of a conventional rolling bearing with a double seal structure

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3. This sealed type rolling bearing is used as an intermediate bearing that supports a drive shaft connection part of an automobile divided into a plurality of parts or an intermediate bearing (so-called center bearing) that supports a connection part of an automobile propeller shaft divided into a plurality of parts. The For example, as shown in FIG. 3, a plurality of drive shafts 40 that transmit rotation from a differential gear of an automobile to left and right wheels are connected via a constant velocity joint 41 on the wheel side and a constant velocity joint 42 on the differential gear side. The split shafts 43, 44, 45 are used as intermediate bearings 46 that support the split shaft 45 on the differential gear side in the vicinity of the constant velocity joint 42.

  As shown in FIG. 1, this sealed type rolling bearing has a ball 3 held by a cage 4 between inner and outer races, that is, an inner ring 1 and an outer ring 2, and a bearing space 5 between the inner ring 1 and the outer ring 2 is formed. The ball bearing has a double seal structure sealed with an inner seal 6 and an outer seal 7 in the axial direction.

  As shown in FIG. 2, the inner seal 6 includes an outer peripheral edge portion 11 fitted in a fitting groove 2 a provided on an inner peripheral surface of the outer ring 2 (one raceway ring), and an axis of the outer peripheral edge portion 11. A rising portion 12 extending radially inward from the outer end in the direction perpendicular to the axial direction, a first inclined portion 13 extending inclined inward in the axial direction from the radially inner end of the rising portion 12, and a diameter of the first inclined portion 13. A central portion 14 extending radially inward from the inner end in the direction perpendicular to the axial direction, a second inclined portion 15 extending obliquely inward from the radial inner end of the central portion 14 in the axial direction, and a diameter of the second inclined portion 15 This is a contact seal having a seal lip 16 extending from the inner end in the axial direction to the outer side in the axial direction and in sliding contact with the sliding contact surface 1a formed on the outer periphery of the inner ring 1 (the other race ring).

  That is, in the inner seal 6, the outer peripheral edge portion 11 becomes a fitting portion to be fitted to the outer ring 2, and the rising portion 12, the first inclined portion 13, the central portion 14, the second inclined portion 15, and the seal lip 16 are The seal portion extends from one end of the fitting portion toward the inner ring 1. The distal end side and a part of the proximal end side of the seal portion (the first inclined portion 13 and the second inclined portion 15) are the directions in which the distal end (seal lip 16) of the seal portion approaches the axial center of the bearing space 5. It is inclined to.

  The inner seal 6 is formed by vulcanizing and molding a rubber material (for example, nitrile rubber) on the surface of the annular cored bar 8. In the example shown in FIGS. 1 and 2, the rubber material is not vulcanized on the inner surfaces of the rising portion 12, the first inclined portion 13, and the central portion 14, but the rubber material is entirely applied to the surface of the cored bar 8. May be vulcanized and molded. Moreover, you may make it form the inner side seal 6 whole with a synthetic resin.

  The outer seal 7 includes a cylindrical portion 17 fitted and fixed to a small-diameter fitting surface 1b formed in the vicinity of the axial end surface of the inner ring 1, and a seal sliding contact surface 1a and a fitting surface 1b of the inner ring 1. A flange portion 18 that abuts against the stepped surface 1c therebetween and extends radially outward from the inner end in the axial direction of the cylindrical portion 17 at right angles to the axial direction, and extends obliquely outward in the axial direction from the radially outer end of the flange portion 18. The slinger has an inclined portion 19 and is not in contact with the outer ring 2.

  That is, in the outer seal 7, the cylindrical portion 17 is a fitting portion that is fitted to the inner ring 1, and the flange portion 18 and the inclined portion 19 are sealing portions that extend from one end of the fitting portion toward the outer ring 2. .

  The outer seal 7 is made of a metal such as a steel plate, but can also be made of a synthetic resin.

  The flange portion 18 of the outer seal 7 is arranged on the same plane perpendicular to the axial direction and radially inward of the rising portion 12 of the inner seal 6 and extends along the central portion 14 of the inner seal 6. 7 of the inner seal 6 extends obliquely with respect to the axial direction so as to follow the first inclined portion 13 of the inner seal 6, whereby the inner surface of the outer seal 7 and the outer seal portion of the inner seal 6 are removed. A labyrinth gap 9 extending in the radial direction is formed between the side surfaces.

  Here, the inclined portion 19 of the outer seal 7 is formed so that the angle formed with the axial direction is slightly larger than that of the first inclined portion 13 of the inner seal 6, whereby the inclined portion 19 of the outer seal 7 and the inner seal 6 The labyrinth gap 9 between the first inclined portion 13 is formed narrower toward the inlet side when viewed from the outside of the bearing, and can effectively prevent intrusion of mud or the like in the muddy water into the bearing. .

  This sealed rolling bearing has the above-described configuration, and the seal portion of the inner seal 6 has a bearing space 5 in the vicinity of the outer peripheral surface of the inner ring 1 as compared with the conventional double-sealed sealed rolling bearing shown in FIG. Therefore, a portion (fitting surface 1 b) to which the outer seal 7 on the outer peripheral surface of the inner ring 1 is attached is provided inside the bearing space 5, and the seal portion of the outer seal 7 is the seal portion of the inner seal 6. Since the labyrinth gap 9 extending relatively long along the radial direction is formed between the outer circumferential surface of the outer ring 2 and the outer circumferential surface of the outer ring 2, a labyrinth forming surface that forms a labyrinth clearance with the seal portion of the outer seal is provided. There is no need. Therefore, the entire bearing can be made compact in the axial direction by reducing the width dimension of the inner ring 1 and the outer ring 2 as compared with a conventional double-sealed sealed rolling bearing while ensuring good mud water resistance.

  In the above-described embodiment, the inner seal 6 is a contact seal attached to the outer ring 2 and the outer seal 7 is a non-contact slinger attached to the inner ring 1. However, the outer seal may be a contact seal, The attachment of the seal may be reversed, and the inner seal may be attached to the inner ring and the outer seal may be attached to the outer ring.

  In the above-described embodiment, the sealed rolling bearing of the present invention is used as an intermediate bearing (center bearing) 46 that supports a connecting portion of a drive shaft 40 of an automobile divided into a plurality of parts as shown in FIG. As described above, the sealed rolling bearing of the present invention can also be used as an intermediate bearing (center bearing) that supports a connection portion of a propeller shaft of an automobile divided into a plurality of parts. For example, when a propeller shaft 40 that transmits rotation from an automobile engine to a differential gear is composed of a plurality of split shafts 43, 44, 45 connected via constant velocity joints 41, 42, the propeller shaft 40 is It can be used as an intermediate bearing 46 that is supported in the vicinity of the speed joint 41 or 42.

  Further, the present invention is not limited to the ball bearing used as an intermediate bearing of the drive shaft and propeller shaft of the automobile as in the embodiment, but is a sealed type with a double seal structure used in a severe environment subject to scattering of muddy water and the like. If it is a rolling bearing, it can be effectively applied to other types of rolling bearings such as roller bearings.

DESCRIPTION OF SYMBOLS 1 Inner ring 1a Sliding contact surface 1b Fitting surface 2 Outer ring 2a Fitting groove 3 Ball 4 Cage 5 Bearing space 6 Inner seal 7 Outer seal 8 Core metal 9 Labyrinth gap 11 Outer peripheral edge 12 Rising part 13 First inclined part 14 Center Part 15 Second inclined part 16 Seal lip 17 Cylindrical part 18 Flange part 19 Inclined part

Claims (6)

In a sealed type rolling bearing with a double seal structure in which the bearing space between the inner and outer races is sealed with an inner seal and an outer seal in the axial direction,
The inner seal includes a fitting portion that is fitted to one of the two race rings, and a seal portion that extends from one end of the fitting portion toward the other race ring, and the seal portion. And at least a part of the base end side is inclined in a direction in which the tip of the seal portion approaches the axial center of the bearing space,
The outer seal includes a fitting portion that is fitted to the other raceway ring, and a seal portion that extends from one end of the fitting portion toward the one raceway ring. A sealed rolling bearing characterized in that a labyrinth gap is formed between an outer surface of a seal portion.   2. The sealing according to claim 1, wherein the inner seal is a contact seal whose seal portion is in sliding contact with the other race ring, and the outer seal is a slinger that is not in contact with the one race ring. Type rolling bearing.   The sealed roller bearing according to claim 2, wherein the inner seal is formed by vulcanizing and molding a rubber material on the whole or a part of the core metal.   The hermetic rolling bearing according to claim 2, wherein the inner seal is made of a synthetic resin.   5. The sealed type rolling bearing according to claim 2, wherein the outer seal is made of metal or synthetic resin.   6. The intermediate bearing for supporting a connection portion of a drive shaft of a vehicle divided into a plurality of parts or an intermediate bearing for supporting a connection portion of a propeller shaft of a vehicle divided into a plurality of parts. The sealed rolling bearing according to any one of the above.

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