JP2005054909A - Sealed anti-friction bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealed anti-friction bearing in which a contact condition of a seal groove with a lip scarcely changes even rotating it at high speed, and a good contact condition is maintained, and leakage of grease and invasion of a foreign substance from the outside can be securely prevented. <P>SOLUTION: An elastic body 22 of a sealing device 20 is provided with a neck 22b extended in the inner surface direction from a sealing cored bar 21, a first lip 22c slidably in contact with a side wall 12d of a sealing groove 12a of an inner ring 22 branched toward the axial inside, a second lip 22d slidably in contact with an opposite arrangement or circumferential surface 12e at a collar, and a third lip 22e arranged oppositely. The neck 22b is tilted. The length L in the radial direction is greater than the axial thickness W, and the first lip side cross sectional area S1 which is divided with a center line CL of the neck section is greater than the second lip side cross sectional area S2. An angle &theta;1 of a connected part of the neck 22b with first lip 22c is greater the axial direction inside angle &theta;2 of the neck collar. The third lip 22e does not contact the circumference 12b of an inner ring 12. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to a sealed rolling bearing, and more particularly to a sealed rolling bearing that includes a sealing device and prevents leakage of enclosed grease and entry of foreign matter such as dust, water, and the like from the outside.

  In an automobile engine room, auxiliary members such as an alternator and an air conditioner compressor, and pulleys for driving the auxiliary devices are rotatably supported by rolling bearings. . Such rolling bearings are used under bad conditions where foreign substances such as water, mud sand, and muddy water are likely to enter.If foreign substances enter the inside of the rolling bearing, the lubrication state deteriorates and the bearing performance may be deteriorated. there were.

  In addition, if the enclosed grease leaks to the outside, it not only interferes with the lubrication of the rolling bearing, but also adheres to nearby devices, parts, etc., causing a problem of functional degradation of those devices. . For example, if leaked grease adheres to the belt or pulley, belt slip occurs, causing abnormal wear, overheating, and the like. Moreover, when attached to the electromagnetic clutch, there is a concern about problems such as clutch slipping. Rolling bearings used in electromagnetic clutches and idle pulleys are generally used as outer ring rotating types, and rotate at high speeds depending on the engine speed and are used under severe conditions with large speed fluctuations. Is done.

Rolling bearings used in the environment as described above are provided with sealing devices on both sides of the rolling bearing, and a lubricant such as grease is sealed inside to prevent the entry of foreign matter from the outside. Sealed rolling bearings that prevent leakage of grease are used. As a conventional sealed-type rolling bearing, a sealed-type rolling bearing in which a sealing plate formed with three lips of an inner lip, an intermediate lip, and an outer lip is disposed on both sides of the rolling bearing is disclosed (for example, (See Patent Document 1).
Japanese Utility Model Publication No. 54-56050 (page 3-6, Fig. 1)

FIG. 5 is a longitudinal sectional view of an essential part of a conventional sealed rolling bearing disclosed in Patent Document 1. As shown in FIG.
As shown in FIG. 5, the sealing plate 2 disposed in the conventional sealed rolling bearing 1 has an inner lip 2a extending inward in the axial direction and an intermediate lip 2b having high flexibility extending in the radial direction. And an outer lip 2c branched from the intermediate lip 2b and extending outward in the axial direction.

  The inner lip 2a is disposed opposite to the peripheral surface 3a of the seal groove 3 with a gap t1, and the inner lip 2a and the peripheral surface 3a form a labyrinth packing to prevent grease leakage. The intermediate lip 2b is in contact with the inner wall 3b of the seal groove 3 to block the inside and outside of the sealed rolling bearing 1. The outer lip 2c is disposed opposite to the outer peripheral wall 3c of the seal groove 3 with a gap t2, and interlocks with the intermediate lip 2b to form a labyrinth packing between the outer lip 2c and the outer peripheral wall 3c. The wall 3c is brought into contact with the outside to prevent entry of foreign matter.

  The intermediate lip 2b and the outer lip 2c are interlocked by the movement of the root of the intermediate lip 2b. For example, when the outer lip 2c is in contact with the outer peripheral wall 3c, the intermediate lip 2b is subjected to wear or contact pressure. When the reduction occurs, the contact pressure between the outer lip 2c and the outer peripheral wall 3c is increased. Further, when the outer lip 2c is not in contact with the outer peripheral wall 3c of the seal groove 3 and the gap t2 is provided, if the intermediate lip 2b wears or the contact pressure decreases, the outer lip 2c has the gap t2 By moving in the decreasing direction, the sealing performance of the outer lip 2c is improved, and the deterioration of the sealing performance as a whole is prevented.

  However, the sealed rolling bearing 1 disclosed in Patent Document 1 does not take into account the influence of centrifugal force caused by rotation, and cannot sufficiently exhibit satisfactory performance when the rolling bearing is rotated at a high speed. was there. In particular, the outer diameter portion of the sealing plate 2 is fixed to the outer ring rotating at a high speed, and the lips (the inner lip 2a, the intermediate lip 2b and the outer lip 2c) formed on the inner diameter portion of the sealing plate 2 are applied to the seal groove 3 with a predetermined pressure. In the sealed rolling bearing 1 that is sealed by contact with (tight force), the contact state between the lips 2a, 2b, 2c and the seal groove 3 is released by the centrifugal force acting on the lips 2a, 2b, 2c ( There is a concern that the sealing performance may be reduced due to a decrease in tightening force, and the enclosed grease may leak or foreign matter may enter from the outside and adversely affect the bearing life.

  The present invention has been made in view of the above-described problems, and its purpose is to achieve a good contact state with almost no change in the contact state between the seal groove and the lip even when the sealed-type rolling bearing rotates at a high speed. An object of the present invention is to provide a sealed type rolling bearing that can maintain and reliably prevent leakage of encapsulated grease and entry of foreign matter from the outside.

In order to achieve the above-described object, a sealed rolling bearing according to the present invention includes an outer ring having an outer ring raceway surface formed on an inner peripheral surface and a seal fixing groove provided on a side end, and an inner ring raceway on an outer peripheral surface. An inner ring having a surface formed with a seal groove at a side end, a plurality of rolling elements arranged to roll on the outer ring raceway surface and the inner ring raceway surface, and the seal fixing groove of the outer ring A sealing-type rolling bearing comprising: a sealing device having a sealing core metal and an annular elastic body fixed to the sealing core metal;
The elastic body includes a neck portion extending in an inner circumferential direction from the seal-shaped cored bar, a first lip branched from the neck portion toward the inner side in the axial direction and slidably in contact with a side wall of the seal groove of the inner ring, and the neck portion A second lip that is branched outward from the axial direction with a predetermined clearance from the outer peripheral surface of the mouth portion of the seal groove of the inner ring or that is slidably in contact with the outer peripheral surface of the mouth portion, and a base portion of the neck portion. A third lip disposed opposite to the outer peripheral surface of the inner ring with a predetermined gap;
The neck portion is inclined inward in the axial direction of the rolling bearing and has a radial length larger than an axial thickness, and a first lip side cross-sectional area divided by a center line of the neck cross section is a second lip side section. And the angle of the joint between the first lip and the neck is set to be larger than the axially inner angle of the neck base, and the third lip includes the first lip and the neck When the second lip is displaced in the axial direction, the second lip is not in contact with the outer peripheral surface of the inner ring.

  According to the sealed rolling bearing according to the present invention, the inner peripheral edge of the annular elastic body as a sealing device is extended in the inner peripheral direction, the neck is provided, and the neck is branched from the neck toward the inner side in the axial direction. The first lip is formed, the second lip is formed by branching from the neck portion toward the outer side in the axial direction of the inner ring, and the third lip is formed by branching from the root portion of the neck portion. The second lip is placed in sliding contact with the outer peripheral surface of the mouth part of the seal groove with a predetermined clearance, or is slidably contacted with the outer peripheral surface of the mouth part, and the third lip is placed on the outer periphery of the inner ring. Since the outer peripheral edge of the sealing device is fixed to the seal fixing groove of the outer ring with a predetermined clearance from the surface, the inside and outside of the sealed rolling bearing is shut off by the sealing device and sealed. Leakage of grease and invasion of foreign matter from outside It is possible to reliably prevented. This also makes it possible to maintain the lubrication condition of the sealed rolling bearing well over a long period of time and to prolong the life of the bearing.

  In addition, the angle of the joint between the first lip and the neck is set to be larger than the angle inside the neck at the base of the neck, so the sealing device is mounted by sliding the first lip against the side wall of the seal groove of the inner ring. In this case, the stress generated at the base of the neck is greater than the stress generated at the joint between the first lip and the neck, and the neck can be bent from the base or the vicinity thereof. Furthermore, since the length of the neck in the radial direction is larger than the thickness in the axial direction, the neck can be easily bent in the axial direction by bending the neck from the base or the vicinity thereof. Therefore, the first lip can slide in contact with the side wall of the seal groove of the inner ring that rotates relative to each other, and can maintain a good sealing performance.

  Further, the neck portion is inclined toward the inner side in the axial direction of the sealed rolling bearing, and the first lip side sectional area divided by the center line of the neck section is larger than the second lip side sectional area. The urging force of the lip on the side wall of the seal groove does not change even when the sealed rolling bearing rotates at a high speed, or can be kept to a slight extent. Therefore, the sealing performance by the first lip can be favorably maintained regardless of the rotational speed of the sealed rolling bearing.

  Further, since the first lip and the second lip are formed by branching from the neck portion toward the inner side and the outer side in the axial direction of the inner ring, the second lip can be displaced in the reverse direction in conjunction with the displacement of the first lip. If the wear of the first lip or a decrease in the pressing force occurs, the second lip is displaced in a direction approaching the outer peripheral surface of the mouth portion of the seal groove. As a result, the sealing performance as a whole can be maintained in a good state for a long time, and the life of the bearing can be extended.

  In addition, the third lip is formed by branching from the base of the neck, and is disposed opposite to the outer peripheral surface of the inner ring with a predetermined gap. Therefore, even if the first lip and the second lip are displaced, , Almost no displacement. Therefore, regardless of the displacement of the first lip and the second lip, the gap between the third lip and the outer peripheral surface of the inner ring can be maintained constant, and the sealed lip bearing is sealed inside as the rotational speed increases. Even if the grease flows faster, it is possible to prevent the grease from leaking by preventing the grease from flowing in the first lip direction. Moreover, this can extend the life of the bearing.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view of a sealing device according to the present invention, FIG. 2 is a longitudinal sectional view of the sealing device in FIG. 1 overlaid on a rolling bearing, and FIG. 3 is a state in which the sealing device in FIG. 1 is mounted on the rolling bearing. FIG. 4 is a graph showing the change in the tightening force of the first lip with respect to the rotational speed of the outer ring in a dimensionless manner with reference to the tightening force when the sealing device is mounted.

  As shown in FIG. 1, the sealing device 20 has elasticity such as rubber, synthetic resin, etc. on a ring-shaped cored bar 21 in which a plate material having high rigidity such as metal, synthetic resin, etc. is formed in a ring shape. The elastic body 22 is integrally formed and fixed in an annular shape, and the mechanical strength of the elastic body 22 is reinforced by the ring-shaped cored bar 21. On the outer peripheral edge of the sealing device 20, a fixed portion 22 a is formed by wrapping an outer diameter portion 21 a of a ring-shaped cored bar 21 with an elastic body 22.

  An elastic body 22 extends in the inner circumferential direction to form an annular neck portion 22b on the inner circumferential side of the ring-shaped cored bar 21. A sealing member, which will be described later, is formed on the inner circumferential end of the neck portion 22b. When mounted on the shape rolling bearing 10, the first lip 22c is branched inward in the axial direction of the sealed rolling bearing 10, and the second lip 22d is branched in the axially outer side. The radial length L of the neck 22b is longer than the axial thickness W. Accordingly, the neck portion 22b can be easily bent from the root portion, and the first lip 22c and the second lip 22d are displaced in conjunction with each other when the neck portion 22b is bent from the root portion.

  Further, a third lip 22e is branched from the base portion of the neck portion 22b toward the inner side in the axial direction of the sealed rolling bearing 10. Since the third lip 22e branches off from the base of the neck portion 22b and is formed independently, the third lip 22e is hardly affected by the bending of the neck portion 22b, and is hardly affected even if the first lip 22c and the second lip 22d are displaced. There is no displacement.

  The neck portion 22 b is formed so as to incline toward the inner side in the axial direction of the sealed rolling bearing 10. Further, the first lip side sectional area S1 divided by the center line CL of the neck section is larger than the second lip side sectional area S2. Further, the angle θ1 of the joint portion between the first lip 22c and the neck portion 22b is set to be larger than the axial inner angle θ2 of the root portion of the neck portion 22b.

  As shown in FIG. 2, the sealed rolling bearing 10 includes an outer ring 11, an inner ring 12, a plurality of balls 13 that are rolling elements, a cage 14 that rotatably holds the plurality of balls 13, and a sealing device 20. A deep groove ball bearing provided. The outer ring 11 has an outer ring raceway surface 11c formed on the inner peripheral surface 11b and a seal fixing groove 11a provided on the side end. The inner ring 12 has an inner ring raceway surface 12c formed on the outer peripheral surface 12b and a seal groove 12a provided at a side end. The plurality of balls 13 are aligned at a predetermined interval in the circumferential direction by a cage 14, are rotatably held, and are rotatably arranged on the outer ring raceway surface 11c and the inner ring raceway surface 12c.

  As shown in FIG. 2, in the sealing device 20, the fixing portion 22a is press-fitted and fixed in the seal fixing groove 11a of the outer ring 11, and is mounted on the sealed rolling bearing 10, but the elastic body 22, particularly the neck portion 22b is deformed. In the free state, the first lip 22c interferes with the side wall 12d of the seal groove 12a by a distance X. That is, the distance X acts as a fastening allowance X when the sealing device 20 is mounted on the sealed rolling bearing 10. The second lip 22d interferes with the outer peripheral surface 12e of the mouth portion of the seal groove 12a by a distance Y.

  As shown in FIG. 3, when the fixing portion 22a of the sealing device 20 is press-fitted into the seal fixing groove 11a and fixed to the outer ring 11, the neck portion 22b is bent outward in the axial direction from the root portion, and the first lip 22c is formed. The side wall 12d of the seal groove 12a is brought into contact with the contact pressure of the tightening margin X. Further, the second lip 22d is disposed oppositely with a slight clearance C1 formed between the neck portion 22b and the outer peripheral surface 12e of the mouth portion of the seal groove 12a by bending the neck portion 22b outward from the root portion. The lip 22d and the mouth portion outer peripheral surface 12e of the seal groove 12a constitute a labyrinth packing to perform a sealing action. Or you may make it the 2nd lip 22d lightly contact the mouth part outer peripheral surface 12e. The third lip 22e is disposed opposite to the outer peripheral surface 12b of the inner ring 12 with a slight clearance C2 to constitute a labyrinth packing.

Next, the operation of this embodiment will be described.
As shown in FIG. 3, the sealed rolling bearing 10 of the present invention is sealed at both ends by a sealing device 20, and grease (not shown) is sealed in the internal space to lubricate the balls 13. The first lip 22c is formed on the side wall of the seal groove 12a by bending the neck 22b outward in the axial direction around the intersection A between the center line CL of the neck cross section and the inner peripheral surface of the ring-shaped cored bar 21 from the base and its vicinity. 12d is contacted with a tightening allowance X and sealed.

  The second lip 22d is disposed to face the outer peripheral surface 12e of the mouth portion with a slight clearance C1 and acts as a labyrinth packing to prevent foreign matters from entering mainly from the outside of the sealed rolling bearing 10. The second lip 22d is displaced in conjunction with the first lip 22c when the neck portion 22b is bent. For example, the first lip 22c is worn or a pressing force to the side wall 12d of the seal groove 12a. 3 is reduced, the neck portion 22b is pivotally displaced about the intersection point A in the clockwise direction in FIG. This rotational displacement is based on the elastic force of the neck 22b. As a result, the first lip 22c comes into contact with the side wall 12d of the seal groove 12a or maintains a tight force, and the second lip 22d is displaced in a direction approaching the outer peripheral surface 12e of the mouth portion to narrow the clearance C1, The sealing function is maintained.

  Further, the third lip 22e is disposed opposite to the outer peripheral surface 12b of the inner ring 12 with a clearance C2, and acts as a labyrinth packing, mainly preventing the enclosed grease from leaking to the outside. The third lip 22e branches off from the base of the neck 22b and is formed independently of the first lip 22c and the second lip 22d. For example, the first lip 22c is worn or the side wall of the seal groove 12a Even if the tightening force to 12d is reduced and the neck portion 22b is rotationally displaced about the root portion, it is hardly affected. That is, the clearance C2 between the third lip 22e and the outer peripheral surface 12b of the inner ring 12 is equal to or slightly smaller than the clearance C3 in FIG. Therefore, the leakage of grease to the outside is stably prevented.

  Since the third lip 22e is non-contacted, an increase in rotational torque can be avoided, and furthermore, the first lip 22c and the seal groove 12a are passed through the clearance C2 with a very small amount of the base oil of the enclosed grease. Is supplied and lubricated to the sliding contact surface with the side wall 12d.

  When the sealing device 20 rotates with the outer ring 11, a centrifugal force acts on the sealing device 20 along with this, and affects the elastic body 22. In particular, the first lip 22c and the second lip 22d formed by branching from the tip of the neck portion 22b having a long and easy bending shape are sealed rolling bearings at the center of gravity G of the neck portion 22b, the first lip 22c and the second lip 22d. The centrifugal force F acts greatly outwardly in the direction perpendicular to the ten rotation axes.

  At this time, the first lip side sectional area S1 divided by the center line CL of the neck section is larger than the second lip side sectional area S2, and the neck 22b is inclined inward in the axial direction when the sealing device is mounted. Therefore, the center of gravity G of the neck portion 22b, the first lip 22c, and the second lip 22d is rotated from the intersection A of the center line CL of the neck section and the inner peripheral surface of the ring-shaped cored bar 21. It is located on the virtual straight line PL drawn in the direction perpendicular to the vertical axis or on the inner side in the axial direction by a slight distance r from the virtual straight line L.

  When the center of gravity G of the neck 22b, the first lip 22c, and the second lip 22d is located on the virtual straight line PL, the centrifugal force F only acts to compress the neck 22b, and the first lip 22c There is no change in the tightening force and the clearance C1 of the second lip 22d. When the center of gravity G of the neck 22b, the first lip 22c, and the second lip 22d is located inward in the axial direction by a distance r from the virtual straight line PL, the centrifugal force F acts as a bending moment F × r, and the neck 22b It acts to bend in the clockwise direction in FIG.

  As a result, the first lip 22c is pressed against the side wall 12d of the seal groove 12a, and the tightening force of the first lip 22c is increased. At the same time, the second lip 22d approaches the mouth portion outer peripheral surface 12e and the clearance C1 is narrowed. However, since the distance r is a slight distance, the bending moment F × r is also small, and the amount of increase in the tension force and the amount of decrease in the clearance C1 are extremely small and hardly change. Therefore, it is possible to always maintain a substantially constant good sealing performance regardless of the rotation speed of the outer ring 11.

  Note that it is preferable that the center of gravity G is positioned on the virtual straight line PL by examining the shape, weight, and the like of the neck portion 22b, the first lip 22c, and the second lip 22d in detail. Accordingly, it is possible to obtain a stable sealing performance by keeping constant the tension of the first lip 22c and the clearance C1 between the second lip 22d and the outer peripheral surface 12e of the mouth portion irrespective of the rotation speed of the outer ring 11. It becomes.

  Further, since the first lip side sectional area S1 divided by the center line CL of the neck section is set larger than the second lip side sectional area S2, the center of gravity G of the neck part 22b, the first lip 22c and the second lip 22d. However, it is not positioned on the outside in the axial direction from the virtual straight line PL. Therefore, the contact between the first lip 22c and the side wall 12d of the seal groove 12a is released by the centrifugal force F, and the sealing performance is not deteriorated.

  Further, as shown in FIG. 1, the angle θ1 of the joint portion between the first lip 22c and the neck portion 22b is larger than the axial inner angle θ2 of the neck base portion, and the first lip 22c is the side wall of the seal groove 12a. 12d, the stress generated at the base of the neck becomes larger than the stress generated at the joint between the first lip 22c and the neck 22b, and the neck 22b It is easily bent from the root portion or its vicinity with A as the center. Accordingly, the first lip 22c can reliably follow the side wall 12d of the seal groove 12a of the inner ring 12 that rotates at a relatively high speed, and maintain good sealing performance.

  When the outer ring 11 is rotated at a high speed using the sealed rolling bearing 10 shown in FIG. 3, the result of numerical analysis of the change in the contact pressure (stressing force) between the first lip 22c and the side wall 12d of the seal groove 12a is shown. As shown in FIG. The tension force is shown as a dimensionless tension force ratio based on the tension force when the outer ring 11 is stopped.

The conditions used for the numerical analysis are as follows.
Rolling bearing size and type: inner diameter 35 mm, outer diameter 52 mm, width 20 mm. Double row angular contact ball bearing first lip tightening margin: 150 μm
Radial load: 200N
Rotational speed: 0 to 12000 rpm

  Note that the clearance C3 between the third lip 22e and the outer peripheral surface 12b when the sealing device 20 shown in FIG. 2 is in a free state and the neck device 22b shown in FIG. The rate of change between the third lip 22e and the clearance C2 between the outer peripheral surface 12b was 16%. This means that even if the first lip 22c and the second lip 22d are displaced in the axial direction by 150 μm for the fastening allowance and the sealing device 20 is mounted, the influence on the displacement of the third lip 22e is small. Yes.

  As shown in FIG. 4, the tension force ratio gradually increases slightly as the rotational speed of the outer ring 11 increases, and is approximately 1.17 at a rotational speed of 12000 rpm. This means that the neck portion 22b is displaced around the intersection A due to the influence of the centrifugal force F, and the first lip 22c is pressed more strongly against the side wall 12d of the seal groove 12a. Therefore, it can be seen that even when the outer ring 11 rotates at a high speed, the sealing performance does not deteriorate, but rather is strengthened and maintained well.

  For confirmation, the sealed rolling bearing 10 having the above specifications was manufactured and subjected to a rotation test. As a result, contact between the first lip 22c and the side wall 12d of the seal groove 12a was not released even during high-speed rotation. Further, there was no evidence that the third lip 22e was in contact with the outer peripheral surface 12b, and there was no leakage of grease or entry of foreign matter from the outside.

  According to the sealed rolling bearing according to the present invention, the inner peripheral edge of the annular elastic body as a sealing device is extended in the inner peripheral direction, the neck is provided, and the neck is branched from the neck toward the inner side in the axial direction. A first lip is formed, and a second lip is formed by branching from the neck portion toward the axially outer side. Further, a third lip is formed by branching from the base portion of the neck portion, and the first lip is formed in the seal groove of the inner ring. The second lip is slidably contacted with the outer peripheral surface of the mouth part of the seal groove with a predetermined gap or is slidably contacted with the outer peripheral surface of the mouth part, and the third lip is further in contact with the outer peripheral surface of the inner ring. Since the outer peripheral edge of the sealing device is fixed in the seal fixing groove of the outer ring, the inside and outside of the sealed rolling bearing is blocked by the sealing device, and the sealed grease leaks, and Reliably prevent foreign material from entering Rukoto can. This also makes it possible to maintain the lubrication condition of the sealed rolling bearing well over a long period of time and to prolong the life of the bearing.

  In addition, the angle of the joint between the first lip and the neck is set to be larger than the angle inside the neck at the base of the neck, so the sealing device is mounted by sliding the first lip against the side wall of the seal groove of the inner ring. In this case, the stress generated at the base of the neck is greater than the stress generated at the joint between the first lip and the neck, and the neck can be bent from the base or the vicinity thereof. Furthermore, since the length in the radial direction of the neck is larger than the thickness in the axial direction, the neck can be easily bent in the axial direction by bending from the root or the vicinity thereof. Therefore, the first lip can reliably follow the seal groove side wall of the inner ring that rotates relative to the first ring, and maintain good sealing performance.

  Further, the neck portion is inclined toward the inner side in the axial direction of the sealed rolling bearing, and the first lip side sectional area divided by the center line of the neck section is larger than the second lip side sectional area. The urging force of the lip on the side wall of the seal groove does not change even when the sealed rolling bearing rotates at a high speed, or can be kept to a slight extent. Therefore, the sealing performance by the first lip can be favorably maintained regardless of the rotational speed of the sealed rolling bearing.

  Further, since the first lip and the second lip are formed by branching from the neck portion toward the inner side and the outer side in the axial direction of the inner ring, the second lip can be displaced in the reverse direction in conjunction with the displacement of the first lip. If the wear and tightening force of the first lip are reduced, the second lip is displaced in a direction approaching the outer peripheral surface of the mouth portion of the seal groove. As a result, the sealing performance as a whole can be maintained in a good state for a long time, and the life of the bearing can be extended.

  In addition, the third lip is formed by branching from the base of the neck, and is disposed opposite to the outer peripheral surface of the inner ring with a predetermined gap. Therefore, even if the first lip and the second lip are displaced, , Almost no displacement. Therefore, regardless of the displacement of the first lip and the second lip, the gap between the third lip and the outer peripheral surface of the inner ring can be maintained constant, and the sealed lip bearing is sealed inside as the rotational speed increases. Even if the grease flows faster, it is possible to prevent the grease from leaking by preventing the grease from flowing in the first lip direction. Moreover, this can extend the life of the bearing.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

  In the present invention, the rolling bearing using the sealing device has been described as a deep groove ball bearing. However, the present invention is not limited to this, and other types of rolling bearings such as angular ball bearings and various roller bearings are also used. The same effect can be obtained.

It is a principal part longitudinal cross-sectional view of the sealing device which concerns on this invention. It is the principal part longitudinal cross-sectional view which drew the sealing device in FIG. 1 on the rolling bearing. It is a principal part longitudinal cross-sectional view of the sealing type rolling bearing which shows the state with which the sealing device in FIG. 1 was mounted | worn with the rolling bearing. It is a graph which shows the change of the compression force of the 1st lip with respect to the rotation speed of an outer ring | wheel, making it dimensionless on the basis of the compression force at the time of an outer ring | wheel stop. It is a principal part longitudinal cross-sectional view of the sealing-type rolling bearing disclosed by patent document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Sealing type rolling bearing 11 Outer ring 11a Seal fixing groove 11b Inner peripheral surface 11c Outer ring raceway surface 12 Inner ring 12a Seal groove 12b Outer peripheral surface 12c Inner ring raceway surface 12d Seal groove side wall 12e Seal groove mouth outer peripheral surface 13 Ball (rolling element)
20 Sealing device 21 Ring-shaped metal core 22 Elastic body 22a Outer peripheral edge 22b Neck portion 22c First lip 22d Second lip 22e Third lip

Claims (1)

An outer ring in which an outer ring raceway surface is formed on the inner peripheral surface and a seal fixing groove is provided on a side end; an inner ring in which an inner ring raceway surface is formed on the outer peripheral surface and a seal groove is provided on a side end; A plurality of rolling elements arranged on the outer ring raceway surface and the inner ring raceway surface so as to be freely rollable, a circle fixed to the seal-fixing groove of the outer ring and fixed to the seal-type metal core A sealed rolling bearing provided with a sealing device having an annular elastic body,
The elastic body includes a neck portion extending in an inner circumferential direction from the seal-shaped cored bar, a first lip branched from the neck portion toward the inner side in the axial direction and slidably in contact with a side wall of the seal groove of the inner ring, and the neck portion A second lip that is branched outward from the axial direction with a predetermined clearance from the outer peripheral surface of the mouth portion of the seal groove of the inner ring or that is slidably in contact with the outer peripheral surface of the mouth portion, and a base portion of the neck portion. A third lip disposed opposite to the outer peripheral surface of the inner ring with a predetermined gap;
The neck portion is inclined inward in the axial direction of the rolling bearing and has a radial length larger than an axial thickness, and a first lip side cross-sectional area divided by a center line of the neck cross section is a second lip side section. And the angle of the joint between the first lip and the neck is set to be larger than the axially inner angle of the neck base, and the third lip includes the first lip and the neck A sealed rolling bearing, wherein the second lip is not in contact with the outer peripheral surface of the inner ring when displaced in the axial direction.

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