JP2018168888A - Sealed rolling bearing - Google Patents

Abstract

To provide a sealed rolling bearing where a seal member can be attached to a seal groove without remaining edges while preventing an increase in the number of processes in attaching the seal member.SOLUTION: A sealed rolling bearing 1 includes: an outer ring 2; an inner ring 3; and a pair of seal members 10 having a fitting part 12a fittable to a pair of seal fitting grooves 8 provided in inner diameter surface both end parts of the outer ring 2, and seal lip parts 12e, 12d elastically coming into contact with a pair of sealing grooves 9 formed in outer diameter surface both end parts of the inner ring 3. A large diameter shoulder part 2ab of the outer ring 2 has surface roughness that is rougher than surface roughness of the sealing grooves 8.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a sealed type rolling bearing that is required to have water resistance and grease leakage resistance, such as an automobile transmission and an auxiliary machine for an automobile.

  In conventional sealed type rolling bearings, the openings of the inner ring and outer ring are sealed with a sealing member to prevent leakage of grease and other lubricants enclosed in the bearing and to prevent foreign substances (for example, muddy water) from flowing in. Has been.

  As shown in FIG. 9, the sealed roller bearing 100 of the conventional example includes a plurality of balls 106 interposed between raceway grooves 104 and 105 of the outer ring 102 and the inner ring 103 which are raceways, and the shafts of the outer ring 102 and the inner ring 103. An annular seal member 110 is fitted at both ends in the direction. The plurality of balls 106 are held at equal intervals in the circumferential direction by a cage 107.

  This seal member 110 is obtained by reinforcing a rubber portion 112 of synthetic rubber or the like with a core metal 111, and a fitting portion is fitted and fixed in a seal fitting groove 108 formed in the outer ring 102. A seal is formed between the inner end edges of the seal lips 113 and 114 provided on the seal lip and the seal surface of the seal groove 109 of the inner ring 103.

  The seal member 110 prevents the grease inside the bearing from leaking to the outside and prevents the inflow of foreign matter from the outside.

  By the way, as shown in FIG. 10, the sealing member 110 of the sealed rolling bearing 100 is attached to the seal fitting groove 108 by disposing the sealing member 110 on the end face of the outer ring 102 of the rolling bearing 100. The fitting portion is pressed against the side surface (surface facing in the axial direction) of the seal fitting groove 108 and press-fitted into the seal fitting groove 108 using a press-fitting jig (not shown). By this press-fitting, the seal member 110 is attached to the seal fitting groove 108.

  However, since the seal member 110 is formed by reinforcing the rubber portion 112 with the core metal 111, as shown in FIG. 9 and FIG. 11, the press-fitted fitting portion is properly fitted into the seal fitting groove 108 by the elastic restoring force. It does not fit and part of the circumference protrudes and remains. In this specification, the protruding portion where this part remains is referred to as a seal ear residue E. The same applies thereafter. In other words, the sealed rolling bearing 100 is industrially mass-produced, and the seal member 110 is attached to the seal fitting groove 108 by a machine. The shaft center of the outer ring 102 and the shaft center of the seal member 110 are When there is a deviation, or when the roundness of the inner diameter of the seal fitting groove 108 of the outer ring 102 or the roundness of the outer diameter of the fitting portion of the seal member 110 is broken, the fitted fitting portion is elastic. In some cases, the rest of the seal E may remain in the seal groove 108 due to the restoring force.

  When this seal ear residue E is generated, the fitting portion of the seal member 110 is not tightly fitted in the seal fitting groove 108, so that grease leaks from this portion. Further, when the pressure is extreme, the seal member 110 is inclined, and in this case, the contact between the seal lip 114 on the inner diameter side of the seal member 110 and the inner diameter seal groove 109 is not as designed, and the sealing performance is not good. Problems such as becoming stable occur. In addition, the seal member 110 may be detached from the seal fitting groove 108 during the bearing operation.

  In Patent Document 1, in order to prevent the seal member from coming off from the seal fitting groove, a fitting portion that fits with the seal fitting groove of the bearing outer ring is provided on the outer peripheral portion of the plastic seal member. When attaching a laser beam receiving surface to the fitting part and attaching this seal member, the laser beam receiving surface is irradiated with laser light, and the irradiated part is heated to the moldable temperature of the plastic and immediately pressurized. It is disclosed to fit into a seal fitting groove while locally deforming.

JP-A-9-177801

  In the above-mentioned Patent Document 1, since the fitting portion of the seal member is softened by local heating by laser light irradiation and crimped by press-fitting into the seal fitting groove, the sealing member is firmly fitted into the seal fitting groove. Thus, the seal member is prevented from falling off from the seal fitting groove.

  However, in the above, it is necessary to heat the fitting portion of the seal member locally by laser beam irradiation and immediately crimp the fitting portion into the seal fitting groove. For this reason, when attaching the sealing member, a laser beam irradiation process and a press-fitting process are required, which increases the number of processes. Further, in the press-fitting process, there is a problem that the outer ring is deformed and the accuracy of the bearing is affected because the fitting portion of the seal member is caulked in the seal fitting groove.

  SUMMARY OF THE INVENTION Accordingly, the present invention provides a sealed type rolling bearing capable of attaching a seal member to a seal fitting groove without leaving a seal ear without increasing the number of steps when the seal member is attached. Is an issue.

  In order to solve the above-described problems, the present invention provides an outer ring, an inner ring, a fitting portion that fits into a pair of seal fitting grooves provided at both ends of the inner diameter surface of the outer ring, and an outer diameter surface of the inner ring. In a sealed type rolling bearing comprising a pair of seal members having a seal lip portion elastically contacting a pair of seal grooves formed at both ends, an outer ring large-diameter shoulder provided on the outer side in the axial direction of the seal fitting groove The surface roughness of the inner diameter surface of the portion is made rougher than the surface roughness of the seal fitting groove.

  And the surface roughness of the inner diameter surface of the outer ring large-diameter shoulder may be in the range of 0.5 μm to 1.0 μm in terms of arithmetic average roughness (Ra).

  Further, the seal member is composed of a cored bar and a rubber part formed integrally with the cored bar, and the fitting part head of the rubber part fitted in the seal fitting groove of the seal member What is necessary is just to make the surface roughness into 2.5 micrometers or less by arithmetic mean roughness (Ra).

  What is necessary is just to use the said seal | sticker type rolling bearing for the rolling bearing for motor vehicle accessories or a transmission.

  The sealed rolling bearing according to the present invention has a surface roughness of the large-diameter shoulder portion of the outer ring that is made rougher than the surface roughness of the seal fitting groove, so that when the fitting portion of the seal member is press-fitted into the seal groove, The frictional resistance between the joint and the large-diameter shoulder that is the inlet portion of the seal is lowered, the insertion performance of the fitting portion into the seal fitting groove is improved, and the occurrence of the seal ear residue of the seal member can be prevented. .

It is a longitudinal front view which expands and shows a part of sealed-type rolling bearing which concerns on embodiment of this invention. It is sectional drawing which expands and shows the sealing member of FIG. It is typical sectional drawing which shows the state which press-fits a sealing member in the seal fitting groove | channel of the sealing type rolling bearing of this invention. It is typical sectional drawing which shows the seal fitting part part of the sealing type rolling bearing which concerns on embodiment of this invention. It is a figure which shows the frictional force when putting a rubber sheet on a metal flat plate whose arithmetic mean roughness (Ra) is 0.1 μm and pulling the rubber sheet. It is a figure which shows the frictional force when putting a rubber sheet on a metal flat plate whose arithmetic mean roughness (Ra) is 1.0 μm and pulling the rubber sheet. It is sectional drawing which showed the pulley using the sealing type rolling bearing shown in FIG. It is the schematic which shows the example which used the sealed rolling bearing shown in FIG. 1 for the transmission. It is a vertical front view which expands and shows a part of sealed type rolling bearing of a prior art example. It is typical sectional drawing which shows the state which press-fits a sealing member to the seal fitting groove | channel of the sealed rolling bearing of a prior art example. It is typical sectional drawing which shows the seal fitting part part of the sealing type rolling bearing of a prior art example.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 1, the sealed rolling bearing 1 includes an outer ring 2, an inner ring 3, a raceway groove 4 formed on the inner diameter surface of the outer ring 2, and a raceway groove 5 formed on the outer diameter surface of the inner ring 3. And a pair of sealing members 10 provided at both ends for sealing the internal space. The outer ring 2, the inner ring 3, the ball 6 and the cage 7 are metal members. In the present embodiment, the cage 7 is made of iron, but may be made of resin. The sealed rolling bearing 1 of the present embodiment is a deep groove ball bearing.

  Further, the sealed rolling bearing 1 is used, for example, for an automobile auxiliary machine such as an idler pulley described later and a pulley bearing and a transmission bearing used for a timing belt. In the following description, a direction along the central axis of the sealed rolling bearing 1 is referred to as an “axial direction”, and a direction orthogonal to the central axis is referred to as a “radial direction”.

  Grease (not shown) is sealed in the bearing internal space S1 of the sealed rolling bearing 1. Here, the bearing inner space S <b> 1 means a space between the inner diameter surface of the outer ring 2 and the outer diameter surface of the inner ring 3. The consistency of the grease is preferably 200 to 350, for example. When the consistency is less than 200, there is a possibility that oil separation is small and lubrication is poor. When the consistency exceeds 350, the grease becomes soft and easily leaks to the outside of the bearing S2.

  A pair of seal fitting grooves 8 are formed at both ends in the axial direction on the inner diameter surface 2a of the outer ring 2, while the outer diameter surface 3a of the inner ring 3 is formed radially with the pair of seal fitting grooves 8 in the radial direction. A pair of opposed seal grooves 9 are formed.

  The inner surface 2a of the outer ring 2 has a small diameter shoulder 2aa and a large diameter shoulder 2ab. The small-diameter shoulder 2aa is located on the outer side in the axial direction than the raceway groove 4 of the outer ring 2 and on both sides thereof. The large-diameter shoulder 2ab is located outside the pair of seal fitting grooves 8 in the axial direction, has a larger diameter than the small-diameter shoulder 2aa, and has an inner diameter surface located on the outer diameter side of the small-diameter shoulder 2aa. Yes. The seal fitting groove 8 is provided between the small diameter shoulder 2aa and the large diameter shoulder 2ab. This large-diameter shoulder 2ab serves as an inlet when the seal member 10 is press-fitted into the seal fitting groove 8.

  The outer diameter surface 3a of the inner ring 3 has a large diameter shoulder 3aa and a small diameter shoulder 3ab. The large-diameter shoulder 3aa is located on the outer side in the axial direction than the raceway groove 5 of the inner ring 3 and on both sides thereof. The small-diameter shoulder 3ab is positioned outside the pair of seal grooves 9 in the axial direction, the small-diameter shoulder 3ab is smaller in diameter than the large-diameter shoulder 3aa, and its outer diameter surface is closer to the inner diameter than the large-diameter shoulder 3aa. positioned. The seal groove 9 is provided between the large-diameter shoulder 3aa and the small-diameter shoulder 3ab.

  In each of the pair of seal fitting grooves 8 formed in the outer ring 2, a fitting portion 12 a of the seal member 10 is fitted. The seal member 10 includes a metal core 11 and a rubber portion 12 formed integrally with the metal core 11.

  As shown in FIGS. 1 and 2, the cored bar 11 is made of metal and has an annular shape when viewed from the axial direction. The radially outer end 11a of the cored bar 11 is bent toward the inner side in the axial direction. The radially outer end portion 11a of the cored bar 11 faces the seal fitting groove 8 in the axial direction. The radially inner end portion 11b of the cored bar 11 is located below the inner diameter surface 7a of the cage 7 and above the constricted portion 12c of the rubber portion 12 described later.

  The rubber portion 12 is annular when viewed from the axial direction. The rubber portion 12 is made of rubber having excellent oil resistance and heat resistance, such as nitrile rubber, heat-resistant nitrile rubber, hydrogenated nitrile rubber, acrylic rubber, and fluorine rubber. The rubber portion 12 is integrally formed by vulcanization molding on the core metal 11.

  As shown in FIGS. 1 and 2, the rubber portion 12 has a fitting portion 12a, a main body portion 12b, a constricted portion 12c, an inward lip portion 12d, and an outward lip portion 12e. . The fitting portion 12 a is a portion that is fitted in the seal fitting groove 8 and covers the radially outer end portion of the core metal 11. The main body portion 12b is a portion that is located on the inner diameter side of the fitting portion 12a and covers a portion of the core metal 11 excluding the radially outer end portion.

  The constricted portion 12c is a portion located on the inner diameter side with respect to the radially inner end portion of the main body portion 12b. That is, the constricted portion 12 c is located on the inner diameter side with respect to the radially inner end portion of the core metal 11. The constricted portion 12 c is located between the inner diameter surface 7 a of the cage 7 and the outer diameter surface 3 a of the inner ring 3.

  An inward lip portion 12d and an outward lip portion 12e are provided on the inner diameter side of the constricted portion 12c. The inward lip portion 12 d is in contact with the inner surface of the seal groove 9. The outward lip portion 12e is provided on the axially outer side than the inward lip portion 12d, and forms a labyrinth with the small-diameter shoulder portion 3ab formed on the axially outward side of the seal groove 9.

  The seal member 10 is fixed by press-fitting the fitting portion 12 a into the seal fitting groove 8 of the outer ring 2. As described above, there is a case where a seal ear residue is generated in which the press-fitted fitting portion 12a does not properly fit in the seal fitting groove 8 due to the elastic restoring force. Therefore, in the present invention, when the fitting portion 12a of the seal member 10 is press-fitted so as not to generate the seal ear residue, the large-diameter shoulder portion serving as the inlet of the fitting portion 12a and the seal fitting groove 8 is used. The friction resistance of 2ab part is made low and the insertion performance to the seal fitting groove 8 of the fitting part 12a is improved.

  5 and 6 show the results of measuring the frictional force between the metal flat plate and the rubber sheet. A metal flat plate with different surface roughness is prepared, a rubber sheet is placed on the metal sheet, and the frictional force when the rubber sheet is pulled is measured. The rubber sheet used is made of acrylic and has a hardness of HS70. In addition, metal flat plates having arithmetic average roughness (Ra) of 1.0 μm and 0.1 μm were prepared.

  FIG. 5 shows a case where the arithmetic average roughness (Ra) is 0.1 μm, and FIG. 6 shows a case where the arithmetic average roughness (Ra) is 1.0 μm. Usually, the inner diameter surface 2a of the outer ring 2 is finished with an arithmetic average roughness (Ra) of less than 0.1 μm. It is considered that the frictional force shown in FIG. 5 is obtained when the normal inner surface 2a and the fitting portion 12a of the rubber portion 12 come into contact with each other.

  As shown in FIG. 5, when the arithmetic average roughness (Ra) is 0.1 μm, the frictional force is close to 50 N, and the fluctuation of the frictional force is large due to the restoring force of rubber. On the other hand, when the arithmetic average roughness (Ra) is 1.0 μm, the frictional force is smaller than 25N, and the fluctuation of the frictional force is small. From these results, it can be seen that the rougher the surface of the metal on the rubber contact side, the smaller the frictional force and the smaller the fluctuation.

  Therefore, the surface roughness of the large-diameter shoulder 2ab that is the inlet portion of the seal fitting groove 8 is made rougher than the surface roughness of the other inner diameter surface 2a including the seal fitting groove 8, thereby reducing the frictional force. Thereby, the insertability of the seal member 10 can be improved.

  Therefore, as shown in FIGS. 3 and 4, in the present invention, the surface portion 20a of the large-diameter shoulder 2ab of the outer ring 2 is made rougher than the surface roughness of the seal fitting groove 8 to form a low friction region. Yes. The surface roughness of the seal fitting groove 8 is an arithmetic average roughness (Ra) of less than 0.1 μm, and the surface portion 20a of the large-diameter shoulder 2ab is rougher than the roughness of the seal fitting groove 8. The roughness (Ra) is in the range of 0.5 μm to 1.0 μm. Here, when the arithmetic surface roughness (Ra) of the surface portion 20a exceeds 1.0 μm, the head portion 12aa of the seal member 10 is shaved and the sealing performance is deteriorated, so that grease may leak to the outside of the bearing. is there. In addition, when the arithmetic surface roughness (Ra) of the surface portion 20a is less than 0.5 μm, the roughness becomes equivalent to the conventional one, and no superiority can be found.

  The surface roughness of the outer ring seal groove inlet can be made rough by roughening the cutting tool at the time of cutting by the large diameter shoulder 2ab. Further, the large-diameter shoulder portion 2ab may be roughened by coating.

  If the surface of the seal fitting groove 8 is made rough, grease may leak from this portion. Therefore, the surface of the seal fitting groove 8 is set to an arithmetic average roughness (Ra) of less than 0.1 μm.

  Furthermore, in this embodiment, in order to improve the insertability, the arithmetic average roughness (Ra) of 1.5 μm or more of the roughness of the head portion 12aa of the fitting portion 12a of the rubber portion 12 of the seal member 10 is used. It is roughened to be 5 μm or less. Here, the roughness on the side of the seal member 10 that is easy to process is roughened as in the above-described range. By roughening the surface roughness of the seal molding die, the roughness of the head portion 12aa of the fitting portion 12a can be roughened. When the roughness of the head portion 12aa of the fitting portion 12a exceeds 2.5 μm, the sealing performance is deteriorated, and grease may leak out from this portion. Further, when the arithmetic average roughness (Ra) of the head portion 12aa of the seal member 10 is less than 1.5 μm, the roughness of the raceway ring (here, the roughness of the surface portion 20a of the large-diameter shoulder portion 2ab of the outer ring 2). : 1.0 μm), the surface of the head portion 12aa of the seal member 10 and the surface of the surface portion 20a of the large-diameter shoulder portion 2ab easily overlap, and the seal insertion property is not improved.

  As shown in FIG. 3, when the seal member 10 is press-fitted in conformity with the large-diameter shoulder 2ab, the fitting portion 12a and the large-diameter shoulder 2ab come into contact with each other. As shown in FIG. 4, the fitting portion 12a of the seal member 10 smoothly enters the seal fitting groove 8, and the occurrence of the seal ear residue of the seal member 10 can be prevented.

  In this embodiment, both the surface of the large-diameter shoulder 2ab and the surface of the head of the fitting portion 12a are roughened. However, even if the surface of the large-diameter shoulder 2ab is roughened, both are roughened. Although the insertability is slightly reduced, the occurrence of the seal ear residue can be suppressed.

  The sealed rolling bearing 1 of the present embodiment is used as a rolling bearing for an automobile auxiliary machine. As an example of an automobile accessory, an idler pulley (hereinafter simply referred to as a pulley) used as a belt tensioner for a drive belt of an automobile accessory is shown in FIG. FIG. 7 is a sectional view of the structure of the idler pulley. The idler pulley guides a drive belt of an automobile auxiliary machine such as an alternator or a compressor.

  As shown in FIG. 7, the pulley is composed of a pulley body 51 made of steel plate and a sealed rolling bearing 1 fitted to the inner diameter of the pulley body 51. The pulley body 51 is an annular body. The pulley body 51 includes an inner diameter cylindrical portion 51a, a flange portion 51b extending outward from one end of the inner diameter cylindrical portion 51a, an outer diameter cylindrical portion 51c extending in the axial direction from the flange portion 51b, and the other end of the inner diameter cylindrical portion 51a. And a flange portion 51d extending to the inner diameter side. The outer ring 2 of the sealed rolling bearing 1 is fitted to the inner diameter of the inner diameter cylindrical portion 51a, and the outer peripheral diameter of the outer diameter cylindrical portion 51c is provided with a pulley peripheral surface 51e that contacts a belt driven by the engine. . By bringing the pulley peripheral surface 51e into contact with the belt, the pulley serves as an idler.

  In rolling bearings (outer ring rotation bearings) used for pulley bearings as shown in FIG. 7, water resistance requirements are increasing in preparation for a case where an automobile travels on a rough road.

  In the pulley bearing used for the pulley, a seal member 10 is provided between the outer ring 2 and the inner ring 3 in order to prevent foreign matter (here, water such as muddy water) from entering the bearing internal space S1. . Thereby, the water resistance of the pulley bearing can be increased.

  In the above-described embodiment, the sealed rolling bearing 1 is a bearing that supports an idler pulley, but is not limited thereto, and may be a bearing that supports another belt transmission, and is pressed by a hydraulic auto tensioner. Thus, it may be a bearing that supports a tension pulley that absorbs fluctuations in belt tension. Further, the sealed rolling bearing 1 may be used in other automobile auxiliary machines. For example, the sealed rolling bearing 1 may be used for a fan coupling device for an automobile engine, an alternator, a flywheel damper for an automobile engine, a car air conditioner, a water pump, and the like.

  FIG. 8 is a schematic view showing an example in which the sealed rolling bearing 1 according to the embodiment of the present invention is incorporated in a transmission of an automobile. The figure is an example of an automatic transmission. The outer rings 2 of the sealed rolling bearings 1 and 1 are fitted to both ends in the axial direction of the case 23, and both ends of the main shaft 24 are rotatably supported by the inner rings 3 of the bearings 1 and 1, respectively. A counter shaft 25 is provided in the case 23 in parallel with the main shaft 24. The counter shaft 25 has a gear portion that meshes with the gear portion of the main shaft 24, and is rotatably supported by the case 23 via a bearing.

  As described above, when the sealed rolling bearings 1 and 1 are incorporated in a transmission of an automobile, foreign matters such as gear wear powder in the transmission can be reliably prevented from flowing into the bearing.

  In addition, you may use the rolling bearing which concerns on either embodiment for a continuously variable transmission or a manual transmission.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

1: Sealed type rolling bearing 2: Outer ring 2a: Inner diameter surface 2aa: Small diameter shoulder 2ab: Large diameter shoulder 3: Inner ring 3a: Outer diameter surface 3aa: Large diameter shoulder 3ab: Small diameter shoulder 4 and 5: Track groove 6 : Ball 7: Cage 7a: Inner diameter surface 8: Seal fitting groove 9: Seal groove 10: Seal member 11: Core metal 11a: Radial outer end 11b: Radial inner end 12: Rubber portion 12a: Fitting Joint portion 12aa: Head portion 12b: Body portion 12c: Constricted portion 12d: Inward lip portion 12e: Outward lip portion

Claims (5)

Elastic contact with an outer ring, an inner ring, a fitting portion that fits into a pair of seal fitting grooves provided at both ends of the inner ring surface of the outer ring, and a pair of seal grooves formed at both ends of the outer ring surface of the inner ring In a sealed rolling bearing provided with a pair of seal members having a seal lip portion to be
A sealed type rolling bearing characterized in that the surface roughness of the inner diameter surface of the outer ring large-diameter shoulder provided on the outer side in the axial direction of the seal fitting groove is made rougher than the surface roughness of the seal fitting groove.   2. The sealed rolling bearing according to claim 1, wherein the surface roughness of the inner diameter surface of the outer ring large-diameter shoulder is in the range of 0.5 μm to 1.0 μm in terms of arithmetic average roughness (Ra).   The sealed rolling bearing according to claim 1 or 2, wherein the seal member includes a cored bar and a rubber part formed integrally with the cored bar.   The roughness of the surface of the fitting portion head of the rubber portion fitted in the seal fitting groove of the seal member is set to an arithmetic average roughness (Ra) of 2.5 μm or less. 3. A sealed rolling bearing according to 3.   The sealed type rolling bearing according to any one of claims 1 to 4, which is used for a rolling bearing for an automobile auxiliary machine or a transmission.

Images