JP5048427B2 - SEALING DEVICE FOR ROLLING BEARING AND ROLLING BEARING - Google Patents

Description

  The present invention relates to a rolling bearing sealing device suitably used in a rolling bearing that supports a rotating shaft having a high-pressure lubricating oil passage therein, and a rolling bearing provided with such a sealing device.

In some motorcycles, for example, a lubricating oil passage is provided inside a crankshaft, a transmission shaft, etc., and the lubricating oil is pumped to each part. The bearing needs to withstand a large hydraulic pressure, and Patent Document 1 includes an annular cored bar and an elastic seal bonded thereto as a sealing device used in such a rolling bearing. Proposals have been made on the shape.
JP 2003-166548 A

  About the sealing device used for the said use, the required performance has become severe, The thing which can endure high rotation while improving pressure | voltage resistance is calculated | required.

  An object of the present invention is to provide a rolling bearing sealing device and a rolling bearing that have improved pressure resistance and durability.

A rolling bearing sealing device according to the present invention is a sealing device disposed between an inner ring and an outer ring of a rolling bearing, and includes an annular cored bar, an elastic seal bonded to the cored bar, and an axial direction of the cored bar. It consists of a backup ring provided on the inner side, and the cored bar is attached to the backup ring with the elastic seal adhered, and the inner diameter edge of the cored bar is between the cored bar and the backup ring. A gap that allows axial inward movement is formed, and a part of the elastic seal is interposed between the inner diameter edge of the core metal and the inner diameter edge of the backup ring so as to fill a part of the gap. It is characterized by that.

  The sealing device has an annular cored bar and an elastic seal bonded to the cored bar, with a backup ring added to the inner side in the axial direction of the cored bar. Thus, the axial displacement of the cored bar when the pressure of the lubricating oil is applied is suppressed. The backup ring is not brought into contact with the core metal over the entire surface, but a gap is formed between the core metal and the backup ring that allows the inner edge of the inner diameter of the core metal to move inward in the axial direction. Thereby, when the hydraulic pressure rises instantaneously, the cored bar is displaced by this gap, so that the deformation of the cored bar itself is suppressed.

  The elastic seal is bonded to the metal core, and the elastic seal has a lip formed so as to protrude radially inward from the inner peripheral edge of the metal core, and the outer peripheral edge of the metal core from the radially outer side. A covering portion is formed.

  The cored bar is attached to the backup ring with the elastic seal bonded thereto, and the outer peripheral edge of the cored bar is fitted into an annular groove provided in the outer ring with the cored bar attached to the backup ring.

  The metal core is, for example, a disc portion, an outer bent portion bent at a right angle inward in the axial direction at the outer peripheral edge portion of the disc portion, and an obtuse angle inward in the axial direction at the inner peripheral portion of the disc portion. An inner bent portion that is bent and further bent radially inward at an intermediate portion thereof is provided.

  The backup ring includes, for example, a disc portion, a short cylindrical portion and an outward flange that are bent at a right angle inward in the axial direction at the outer peripheral edge portion of the disc portion and further bent radially outward at an intermediate portion thereof. And an inner bent portion that is bent at an obtuse angle in the axially inward direction at the inner peripheral edge of the disc portion and further bent inward in the radial direction at an intermediate portion thereof. It is said.

  The plate thickness of the backup ring is approximately the same as the plate thickness of the cored bar, so that each of the backup ring and the cored bar can be easily processed and a shape with improved rigidity can be obtained.

  The core metal is attached to the backup ring by fitting the outer bent portion thereof to the outer periphery of the short cylindrical portion of the outer bent portion of the backup ring. At this time, the inner side surface in the axial direction of the disk part of the core metal and the outer side surface in the axial direction of the disk part of the backup ring come into contact with each other, and the bending amount of the inner bent part of the backup ring is larger than that of the core metal A large gap is formed between the inner bent portion (inner diameter edge portion) of the core metal and the inner bent portion of the backup ring.

  The sealing device is used in a state where a high hydraulic pressure is applied from the outside in the axial direction to the inside, and the displacement and deformation of the core metal are handled by the hydraulic pressure acting on the core metal by the core metal itself and the backup ring. As a result, the axial force acting on the lip of the elastic seal is suppressed, the lip friction is reduced, the lip wear is reduced, and the fuel efficiency of a motorcycle or the like can be improved. In addition, when excessive hydraulic pressure is applied instantaneously due to fluctuations in hydraulic pressure, the hydraulic pressure acting on the metal core is handled by the metal core itself and the backup ring, and the inner diameter edge of the metal core is axially inward. By displacing, the force acting on the core metal is absorbed, and this damper action reduces the load on the core metal. Thereby, the intensity | strength of a metal core and a backup ring is securable, without making the plate | board thickness of a metal core thick.

  A rolling bearing according to the present invention is a rolling bearing that has an inner ring, an outer ring, and a plurality of rolling elements, and that supports a rotating shaft having a lubricating oil passage therein. A sealing device is provided to prevent intrusion into the bearing, and the sealing device is as described above, and no step portion is formed on the outer peripheral surface of the inner ring where the lip of the elastic seal is in sliding contact. It is characterized by.

  In the conventional sealing device, an annular groove is provided in the inner ring to receive a force from the outside in the axial direction, and the lip of the elastic seal is received by the side surface (stepped portion) of the annular groove. That is, the lip of the conventional sealing device is a lip in the axial direction. For this reason, in the conventional sealing device, when the core bar is deformed inside the bearing by hydraulic pressure, the reaction force of the lip increases, and wear of the lip increases at excessive hydraulic pressure or high rotation, and sufficient sealing performance is secured. It may not be possible.

  On the other hand, according to the rolling bearing to which the above-described sealing device is applied, the force acting on the sealing device is handled by the core metal itself and the backup ring, so that it is not necessary for the lip itself to handle the axial force. Eliminating the step on the outer peripheral surface reduces the burden on the lip, and it is easier to reduce the roughness of the outer peripheral surface of the inner ring than the stepped portion, thus simplifying the turning to the inner ring. And lip friction can be further reduced.

  According to the rolling bearing sealing device and the rolling bearing of the present invention, the force acting on the sealing device is handled by the cored bar itself and the backup ring, so that the movement of the lip is suppressed to be small and the friction is reduced. When the inner diameter edge of the core bar is displaced inward in the axial direction, the force acting on the core bar due to the change in hydraulic pressure is absorbed, and the pressure resistance is improved and the durability is also improved.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the left and right refer to the left and right in FIG.

  1 and 2 show a rolling bearing and a sealing device according to the present invention.

  As shown in FIG. 1, the rolling bearing (1) is composed of an inner ring (2), an outer ring (3), a plurality of balls (rolling elements) (4), a cage (5) and a sealing device (6). Suitable for supporting rotating shafts (8) such as crankshafts and transmission shafts. In this type of rotating shaft (8), a lubricating oil passage (8a) is provided inside, and the lubricating oil passage (8a) is forcibly lubricated in the direction indicated by the arrow by an oil pump (not shown). Supply and send lubricating oil to each part. For this reason, high-pressure lubricating oil is present at one end (right end) of the rolling bearing (1) supported by the housing (9), and the sealing device (6) can withstand this high pressure. It is required to be.

  The rolling bearing (1) is asymmetric in right and left, the raceway grooves of the inner ring (2) and outer ring (3) are provided on the left side of the center in the axial direction, and the sealing device (6) is provided only at the right end. Is provided. An annular groove (7) for mounting the sealing device (6) is provided at the right end of the outer ring (3), and such an annular groove is not provided at the right end of the inner ring (2). . The annular groove (7) of the outer ring (3) is provided with an annular protrusion (7a) that prevents the sealing device (6) once attached from easily slipping out in the axial direction. The annular groove (7) for attaching the sealing device (6) provided on the outer ring (3) can be obtained by the same turning process as in the prior art.

  As shown in the enlarged view of FIG. 2, the sealing device (6) includes an annular metal core (11), an elastic seal (12) bonded to the metal core (11), and the axial direction of the metal core (11). It consists of a backup ring (13) provided on the inner side.

  The metal core (11) includes a disk part (21), an outer bent part (22) bent at right angles in the axial direction at the outer peripheral edge part of the disk part (21), and the disk part (21). And an inner bent portion (23) bent at an obtuse angle inward in the axial direction at the inner peripheral edge and further bent inward in the radial direction at an intermediate portion thereof.

  The disc portion (21) has an outer diameter substantially equal to the inner diameter of the outer ring (3), and has an inner diameter smaller than the intermediate diameter between the inner diameter of the outer ring (3) and the outer diameter of the inner ring (2). . The outer bent portion (22) has a short cylindrical shape, and its inner diameter is equal to the inner diameter of the outer ring (3). The inner bent portion (23) has an inner diameter larger than the outer diameter of the inner ring (2), and a lip (32) described later is provided on the inner edge portion.

  The elastic seal (12) has a U-shaped section (31) in close contact with the inner edge of the inner bent section (23) of the core metal (11) and a bottom surface of the U-shaped section (31). A lip (32) extending obliquely outward in the axial direction, a cover part (33) in close contact with the outer bent part (22) of the metal core (11), and the right side of the U-shaped section (31) And a connecting portion (34) that extends from the cover portion (33) to the disc portion (21) of the cored bar (11). The inner diameter of the lip (32) is smaller than the outer diameter of the inner ring (2), so that the lip (32) is in sliding contact with the outer peripheral surface of the inner ring (2). (33a) and its outer diameter is made larger than the outer diameter of the annular groove (7) of the outer ring (3), so that it can be elastically deformed and fit in the annular groove (7). Yes.

  The backup ring (13) is a disk part (41) and an outer bent part which is bent at a right angle inward in the axial direction at the outer peripheral edge part of the disk part (41) and is further bent outward in the radial direction at an intermediate part thereof. Part (42), and an inner bent part (43) bent at an obtuse angle in the axial direction inward at the inner peripheral edge of the disk part (41) and further bent inward in the radial direction at an intermediate part thereof. ing.

  The disc part (41) has an outer diameter smaller than the outer diameter of the disc part (21) of the core metal (11), and has an inner diameter larger than the inner diameter. The outer bent portion (42) includes a short cylindrical portion (42a) continuous with the disc portion (41) and an outward flange portion (42b) continuous with the axially inner end of the short cylindrical portion (42a). The outer diameter of the short cylindrical part (42a) is slightly smaller than the inner diameter of the outer bent part (22) of the metal core (11), and the outer diameter of the outward flange part (42b) is the outer ring (3 ) Is slightly smaller than the annular groove (7). The inner bent portion (43) includes an inclined portion (43a) connected to the disc portion (41), an inward flange portion (43b) connected to a lower end of the inclined portion (43a), and an inner diameter edge of the inward flange portion (43b). And a bent edge portion (43c) which is bent inward in the axial direction and is in contact with the lip (32) from the inner side in the axial direction.

  The core metal (11) has its outer bent part (22) fitted to the outer periphery of the short cylindrical part (42a) of the outer bent part (42) of the backup ring (13), so that the backup ring (13 ). At this time, the left surface (axial inner surface) of the disk portion (21) of the core metal (11) and the right surface (axial outer surface) of the disk portion (41) of the backup ring (13) are in contact with each other. A predetermined gap (G) is formed between the inner bent portion (23) of the gold (11) and the inner bent portion (43) of the backup ring (13). The predetermined gap (G) is the amount of bending of the inner bent portion (43) of the backup ring (13) (the amount protruding inward in the axial direction with respect to the disc portion (41)) is the core metal (11) It is obtained by being taken larger than the amount of bending of the inner bent portion (23) (the amount projecting inward in the axial direction with respect to the disc portion (21)).

  The metal core (11) is attached to the backup ring (13) with the elastic seal (12) adhered, and the metal core (11) is attached to the backup ring (13). ) Outer bent portion (outer peripheral edge portion) (22) is fitted into an annular groove (7) provided in the outer ring (3). At this time, the outward flange portion (42b) of the backup ring (13) contacts the side surface (step portion) of the annular groove (7), so that the sealing device (6) is positioned and the cover of the elastic seal (12) The sealing device (6) is prevented from coming off by the elastic deformation of the portion (33) and being forcedly accommodated in the annular groove (7) and the annular convex portion (7a).

  According to this sealing device (6), when used under a hydraulic action as shown in FIG. 1, the hydraulic pressure acting on the core metal (11) is the same as the core metal (11) and the backup ring in contact with the core metal (11). 13) and the displacement and deformation of the cored bar (11) can be suppressed. As a result, the elastic seal (12) does not deform so as to come into contact with the cage (5), the axial force acting on the lip (32) is kept small, and the lip (32) friction is reduced. Thus, the wear of the lip (32) is reduced and the sealing performance is maintained. When excessive hydraulic pressure is instantaneously applied due to fluctuations in hydraulic pressure, the hydraulic pressure acting on the core metal (11) is caused by the core metal (11) and the backup ring (13) in contact with the core metal (11). In addition to being able to handle it, a gap (G) is formed between the inner bent portion (23) of the core metal (11) and the inner bent portion (43) of the backup ring (13). The inner bent portion (23) of the core metal (11) can be displaced inward in the axial direction. The axially inward displacement of the inner bent portion (23) absorbs the force acting on the core metal (11), and the damper action reduces the load on the core metal (11). Thereby, the strength of the core metal (11) and the backup ring (13) can be ensured without increasing the plate thickness of the core metal (11).

  The results of comparing the sealing device (6) of the present invention (hereinafter referred to as “invention product”) and a conventional sealing device (hereinafter referred to as “conventional product”) are shown in FIGS.

  As shown in FIG. 6, the conventional sealing device (50) includes an annular cored bar (51) and an elastic seal (52) bonded to the cored bar (51). The annular groove (60) is formed, and the lip (53) of the elastic seal (52) is brought into sliding contact with the side surface (stepped portion) (60a) of the annular groove (60) from the outside in the axial direction (Axial Lip).

  FIG. 3 shows the FEM analysis result on the relationship between the hydraulic pressure and the lip reaction force. According to this, the reaction force of the lip (32) of the invention is about the reaction force of the lip (53) of the conventional product. It is suppressed to 30%. Further, according to the FEM analysis, the axial displacement of the inventive metal core (11) is suppressed to about 40% of the axial displacement of the conventional metal core (51). From these results, it can be seen that lip wear, lip deformation, and friction can be reduced by using the invention.

  Fig. 4 compares the relationship between the hydraulic pressure and the starting torque with the actual measurement value and the calculated value derived from the FEM analysis result. The inventive product has a starting torque reduced to about 1/3 compared to the conventional product. It can be seen that the effect of reducing friction is great. Moreover, in FIG. 4, since the calculated value derived from the FEM analysis result and the actual measurement value almost coincide, it is possible to predict the sealing performance by obtaining the lip reaction force and the core metal deformation by the FEM analysis. I understand that there is.

  FIG. 5 shows the results of the durability test (oil leakage test). The test conditions were: oil pressure: 0.7 MPa, rotation speed: 7000 r / min, time 100 hr, oil temperature 140 ° C. According to this, it can be seen that the oil leakage amount and the lip wear amount are both within the criterion for the invention product and have sufficient performance even after 100 hours.

Thus, according to the sealing device (6) and the rolling bearing (1) described above, the pressure resistance of the conventional device is 0.49 MPa or less, whereas this is 0.7 MPa or more (test time 100 hours). With regard to sealing performance, oil leakage can be reduced to 0.1 cm ³ / min or less, and durability against high rotation can be up to 20 m / s at the peripheral speed of the elastic seal (12). The friction can be reduced to 30% of the conventional product.

FIG. 1 is a longitudinal sectional view showing an embodiment of a rolling bearing and a sealing device according to the present invention. FIG. 2 is an enlarged longitudinal sectional view of the sealing device. FIG. 3 is a graph showing the relationship between the hydraulic pressure of the sealing device and the lip reaction force. FIG. 4 is a graph showing the relationship between the hydraulic pressure of the sealing device and the starting torque. FIG. 5 is a graph showing the change over time in the amount of oil leakage per minute of the sealing device. FIG. 6 is a longitudinal sectional view showing a conventional sealing device.

Explanation of symbols

(1) Rolling bearing
(2) Inner ring
(3) Outer ring
(4) Ball (rolling element)
(6) Sealing device
(11) Core
(12) Elastic seal
(13) Backup ring
(23) Inside bent part (inner diameter edge)
(32) Lip
(G) Gap

Claims (4)

A sealing device disposed between an inner ring and an outer ring of a rolling bearing, an annular cored bar, an elastic seal bonded to the cored bar, and a backup ring provided on the inner side in the axial direction of the cored bar The cored bar is attached to the backup ring with the elastic seal adhered, and allows the inner side edge of the cored bar to move inward in the axial direction between the cored bar and the backup ring. A rolling bearing characterized in that a gap is formed and a part of the elastic seal is interposed between the inner diameter edge of the cored bar and the inner diameter edge of the backup ring so as to fill a part of the gap . Sealing device. The cored bar is bent at an obtuse angle inward in the axial direction at the inner peripheral edge of the disk portion, the outer bent portion bent at a right angle inward in the axial direction at the outer peripheral edge portion of the disk portion. Further, the intermediate portion has an inner bent portion bent radially inward, and the backup ring is bent at a right angle axially inward at the outer peripheral edge portion of the disc portion and the disc portion, and An outer bent portion composed of a short cylindrical portion and an outward flange portion that is bent radially outward at the intermediate portion, and an intermediate portion that is bent at an obtuse angle axially inward at the inner peripheral edge of the disc portion. The inner bent portion bent inward in the radial direction, and the core metal is backed up by fitting the outer bent portion to the outer periphery of the short cylindrical portion of the outer bent portion of the backup ring. Take the ring The axial inner surface of the disk part of the metal core and the axial outer surface of the disk part of the backup ring are in contact with each other, and the amount of bending of the inner bent part of the backup ring is the same as that of the metal core. The rolling bearing sealing device according to claim 1, wherein the gap is formed between the inner bent portion of the core metal and the inner bent portion of the backup ring. A rolling bearing that has an inner ring, an outer ring, and a plurality of rolling elements and that supports a rotating shaft having a lubricating oil passage therein, and injects lubricating oil into the bearing at one of the ends. preventing the sealing device is provided which, together with the sealing device is that of claim 1 or 2 of the rolling bearing sealing device, on the outer peripheral surface of the inner ring lip of the elastic seal in sliding contact with no stepped portion is formed A rolling bearing characterized by that. The outer peripheral edge of the metal core is fitted into an annular groove provided in the outer ring, and at this time, the outward flange portion provided in the backup ring contacts the side surface of the annular groove, thereby positioning the sealing device. The rolling bearing according to claim 3 .

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