JP2017219105A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device capable of properly cutting off between an inside and outside of a rolling bearing, and suppressing increase of torque applied to a rotational shaft.SOLUTION: A sealing device is arranged between an inside member and outside member of a rolling bearing, which relatively rotate to each other, and configured to seal a gap between the inside member and the outside member. The sealing device includes an annular body fixed to the outside member, a radial lip extending radially inward from the annular body, and two side lips extending laterally from the annular body so as to be parallel with each other. On a surface of one side lip opposite to the other side lip, formed is a projection or groove for preventing the two side lips from adhering to each other wholly in a circumferential direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sealing device that seals the inside of a rolling bearing.

  Rolling bearings, such as ball bearings, are well known and are used, for example, in automobile hubs. As a sealing device for sealing the inside of a rolling bearing, there is one described in Patent Document 1. The sealing device includes an annular body fixed to the outer ring of the rolling bearing, a radial lip extending radially inward from the annular body, and two side lips extending laterally from the annular body. The radial lip is in contact with the outer peripheral surface of the inner ring of the bearing or the outer peripheral surface of the component fixed to the inner ring, and has a function of sealing the lubricant inside the bearing, and the two side lips contact the flange of the inner ring. Thus, it has a function of sealing so that foreign matters such as muddy water and dust do not enter the inside of the bearing from the outside.

Japanese Patent No. 3991200

  For this type of sealing device, while the function of blocking the inside and the outside of the bearing is important, it is desirable that the sealing device itself provides as little torque as possible to the rotating shaft.

  Then, an object of this invention is to provide the sealing device which can suppress the raise of the torque given to a rotating shaft while interrupting | blocking the inside and outside of a rolling bearing appropriately.

  In order to solve the above problems, a sealing device according to the present invention is disposed between a relatively rotating inner member and an outer member of a rolling bearing, and seals a gap between the inner member and the outer member. An annular body fixed to the outer member, a radial lip extending radially inward from the annular body, and two side lips extending side by side laterally from the annular body, Projections or grooves for preventing the two side lips from sticking to each other in the entire circumferential direction are formed on the surface of one side lip facing the other side lip.

  If for some reason two side lips are closely attached and integrated over the entire circumferential direction, one side lip may maintain a desired contact state with respect to the inner member or a part fixed to the inner member. The other side lip cannot be applied to the inner member or the component fixed to the inner member. This causes an increase in torque applied to the rotating shaft. Then, this state continues when the space inside the two side lips becomes negative pressure. However, in the sealing device according to the present invention, a protrusion or a groove for preventing close contact of the two side lips in the entire circumferential direction is formed on the surface of the one side lip facing the other side lip. . Therefore, even if two side lips approach each other and some of them contact each other, the inside of the space between the two side lips communicates with the other part, and the two side lips can easily be separated. . For this reason, it is possible to suppress an increase in torque applied to the rotating shaft.

  It is preferable that a plurality of the protrusions or the grooves are provided discontinuously in the circumferential direction of the sealing device. Due to the discontinuity of the protrusions in the circumferential direction, even if the two side lips approach each other and the protrusions come into contact with the opposing side lips, the space inside the two side lips is formed through the part other than the protrusions. Communicate with other parts. In addition, by providing a plurality of discontinuous protrusions in the circumferential direction, compared to the case where a single protrusion is provided, the contact points between the two side lips are dispersed, so the inner member or the inner member is fixed. Variations in the circumferential direction of the contact pressure of both side lips with respect to the part to be processed are reduced. Due to the discontinuity of the groove in the circumferential direction, even if the two side lips approach each other and some of them come into contact with each other, the space inside the two side lips is separated from the other part via the groove. Communicate. Further, by providing a plurality of grooves discontinuously in the circumferential direction, the circumferential direction of the contact pressure of both side lips with respect to the inner member or a part fixed to the inner member as compared with the case where a single groove is provided. Variation is reduced.

  In the present invention, adhesion of the two side lips over the entire circumferential direction is prevented. For this reason, the situation where only one side lip contacts the inner member or a component fixed to the inner member is reduced, and an increase in torque can be suppressed. In addition, since the period during which each of the two side lips contacts the inner member or a part fixed to the inner member is longer, the function of the side lip that prevents the entry of foreign matter from the outside is appropriately maintained.

It is a fragmentary sectional view of an example of the rolling bearing in which the sealing device concerning the embodiment of the present invention is used. It is a fragmentary sectional view of the sealing device concerning a 1st embodiment of the present invention. FIG. 3 is an enlarged sectional view of a part of the sealing device of FIG. 2. FIG. 3 is an enlarged perspective view of a part of the sealing device of FIG. 2. It is a partial expanded sectional view of the sealing device of a comparative example. It is a partial expanded sectional view of the sealing device of the comparative example which shows the disadvantageous situation which may occur with a sealing device. It is the schematic for demonstrating one cause of the disadvantageous situation which can occur in a sealing device. It is a partial expanded sectional view of the sealing device which concerns on 2nd Embodiment of this invention. It is a partial expanded sectional view of the sealing device which concerns on 3rd Embodiment of this invention. It is a partial expanded sectional view of the sealing device which concerns on 4th Embodiment of this invention. It is a fragmentary sectional view of the sealing device concerning a 5th embodiment of the present invention.

Hereinafter, various embodiments according to the present invention will be described with reference to the accompanying drawings.
1st Embodiment FIG. 1: shows the hub bearing for motor vehicles which is an example of the rolling bearing in which the sealing device which concerns on embodiment of this invention is used. However, the application of the present invention is not limited to the hub bearing, and the present invention can also be applied to other rolling bearings. In the following description, the hub bearing is a ball bearing. However, the application of the present invention is not limited to the ball bearing, and other rolling bearings such as roller bearings and needle bearings having other types of rolling elements. In addition, the present invention is applicable.

  The hub bearing 1 is disposed outside a hub (inner member) 4 having a hole 2 into which a spindle (not shown) is inserted, an inner ring (inner member) 6 attached to the hub 4, and an outer side thereof. The outer ring (outer member) 8, the balls 10 arranged in a line between the hub 4 and the outer ring 8, the balls 12 arranged in a line between the inner ring 6 and the outer ring 8, and these balls are fixed. A plurality of retainers 14 and 15 are held in position.

  A common axis of the spindle and the hub bearing 1 extends in the vertical direction of FIG. In FIG. 1, only the left side with respect to the common axis is shown. Although not shown, the upper side in FIG. 1 is the outer side (outboard side) where the wheels of the automobile are arranged, and the lower side is the inner side (inboard side) where the differential gears are arranged. The outer ring 8 of the hub bearing 1 is fixed to the hub knuckle 16. The hub 4 has an outboard side flange 18 for attaching a wheel.

  A sealing device 20 that seals the gap between the outer ring 8 and the hub 4 is disposed inside the end portion of the outer ring 8 on the outboard side, and inside the end portion of the outer ring 8 on the inboard side. A sealing device 22 for sealing the gap between the outer ring 8 and the inner ring 6 is arranged. By the action of these sealing devices 20 and 22, the grease, that is, the lubricant from the inside of the hub bearing 1 is prevented from flowing out, and the inflow of foreign matter from the outside to the inside of the hub bearing 1 is prevented.

  As shown in FIG. 2, the sealing device 20 includes an end on the outboard side of the outer ring 8 of the hub bearing 1, an outer peripheral surface 23 near the ball 10 of the hub 4 of the hub bearing 1, and an outer peripheral surface 23 of the hub 4. It is arranged in a space surrounded by a flange surface 24 that spreads outward and an arc surface 25 that connects the outer peripheral surface 23 and the flange surface 24. Although the sealing device 20 has an annular shape, only the left side portion is shown in FIG.

  The sealing device 20 includes an elastic ring 30 made of an elastic body, for example, an elastomer, and a rigid body that reinforces the elastic ring 30, for example, a reinforcing ring 32 having a substantially L-shaped cross section made of metal. A part of the reinforcing ring 32 is embedded in the elastic ring 30 and is in close contact with the elastic ring 30.

  The sealing device 20 includes a main annular body 26 fixed to the outer ring 8, a radial lip 34 extending radially inward from the main annular body 26, and two side lips 36 extending side by side from the main annular body 26. 38.

  The main annular body 26 is a portion composed of an elastic ring 30 and a reinforcing ring 32. The radial lip 34 and the side lips 36, 38 are formed of only an elastic body, and are thin plate-like rings extending from the elastic ring 30.

  The main annular body 26 is an outer seal portion fixed to the inner peripheral surface of the inner space at the end of the outer ring 8. The fixing method is not limited, but may be an interference fit, for example. A portion extending vertically in FIG. 2 of the reinforcing ring 32, that is, a cylindrical portion is inserted into the internal space at the end of the outer ring 8. A part of the elastic ring 30 is disposed outside the reinforcing ring 32, and the reinforcing ring 32 firmly presses the part against the inner peripheral surface of the inner space at the end of the outer ring 8.

  The radial lip 34 extends radially inward from the main annular body 26 toward the ball 10 that is the rolling element to be sealed, and contacts the outer peripheral surface 23 of the hub 4 in the vicinity of the ball 10. The radial lip 34 plays a role of mainly preventing the lubricant from flowing out from the inside of the hub bearing 1.

  The side lips 36, 38 extend from the main annular body 26 to the side (outboard side in this embodiment) and radially outward. The side lip 36 contacts the flange surface 24 of the hub 4, and the side lip 38 contacts the flange surface 24 or the arc surface 25. The side lips 36 and 38 mainly serve to prevent foreign matters from flowing into the hub bearing 1 from the outside. Compared with the side lip 38, the side lip 36 disposed on the atmosphere side is long, and thus has a high ability to prevent foreign matter. The side lip 38 has a backup function that prevents foreign matter that has flown through the side lip 36. Since the side lip 38 exists between the radial lip 34 and the side lip 36, it can also be called an intermediate lip.

  In the drawing, the radial lip 34 and the side lips 36, 38 when the sealing device 20 is not disposed on the hub bearing 1 are shown. At this time, the radial lip 34 and the side lips 36, 38 are not subjected to external force and are in a straight state. However, in reality, when the sealing device 20 is disposed on the hub bearing 1, these lips contact the hub 4 and are deformed by receiving a reaction force.

  As shown in an enlarged view in FIG. 3, a protrusion 40 is formed on the surface of one side lip 36 that faces the other side lip 38 to prevent the two side lips 36, 38 from closely contacting each other in the circumferential direction. Has been. As shown in FIG. 4, a plurality of protrusions 40 are provided discontinuously in the circumferential direction of the side lip 36 (that is, the circumferential direction of the sealing device 20). As is clear from comparison with FIG. 6, the protrusion 40 is disposed at a position where the tip of the side lip 38 can contact.

  The effect of the protrusion 40 will be described below. Assume a sealing device as shown in FIG. For such a sealing device of the comparative example, as shown in FIG. 6, the two side lips 36 and 38 may be in close contact with each other in the entire circumferential direction for some reason. Possible causes are as follows.

  As shown in FIG. 7, a spiral minute groove may be left on the outer surface of the hub 4 with which the side lips 36 and 38 are in contact with each other by cutting or polishing during manufacture of the hub 4 (processing accuracy). Is low). If such a spiral groove remains when the hub bearing 1 is used, an air current (indicated by an arrow in the figure) is generated by the groove along with the rotation of the spindle and the hub 4, and this air current is shorter. There is a possibility that the side lip 38 is brought closer to the side lip 36 and finally the side lip 38 is brought into contact with the side lip 36 over the entire circumferential direction. Further, as the spindle and the hub 4 rotate, the groove acts as if it is a feed screw. In some cases, the shorter side lip 38 is moved closer to the side lip 36, and finally the side lip 38 is moved in the circumferential direction. There is a possibility of contact with the side lip 36 throughout.

  When the sealing device 20 is eccentric with respect to the hub 4, a part of the tip of the side lip 38 is strongly pressed toward the side lip 36 and moves, and the movement of the hub 4 as the hub 4 rotates. As a result, the side lip 38 may eventually be brought into contact with the side lip 36 over the entire circumferential direction.

  Whatever the cause, if the two side lips 36, 38 are integrated, one side lip (particularly the shorter side lip 38) can maintain the desired contact state with the hub 4. The other side lip (especially the longer side lip 36) gives a large force to the hub 4. This causes an increase in torque applied to the rotating spindle.

  And when the inside of the space between the two side lips 36, 38 becomes negative pressure, this state continues. When the sealing device 20 is used, heat is generated and the temperature rises when the spindle and thus the hub 4 rotates, and the temperature drops when the rotation stops. When the temperature inside the space defined by the two side lips 36 and 38 that come into contact with each other decreases, the inside of the space becomes negative pressure, and the side lips 36 and 38 are kept in close contact with each other. Therefore, when the rotation of the spindle is resumed, the two side lips 36 and 38 are in close contact with each other, and the torque at that time becomes high.

  However, in the sealing device 20, as shown in FIGS. 3 and 4, the surface of the one side lip 36 facing the other side lip 38 is closely adhered to the entire circumferential direction of the two side lips 36, 38. A protrusion 40 is formed to prevent this. Therefore, even if the two side lips 36 and 38 come close to each other and a part of the two lips come into contact with each other, the space inside the two side lips 36 and 38 is connected to the other part via the part other than the protrusion 40. The two side lips 36 and 38 are easily separated from each other. For this reason, the situation where only one side lip contacts the hub 4 is reduced, and it is possible to suppress an increase in torque applied to the spindle.

  In addition, since each of the two side lips 36 and 38 is in contact with the hub 4 for a longer period, the function of the side lips 36 and 38 that prevent entry of foreign matter from the outside is appropriately maintained.

  From the above viewpoint, the number of the protrusions 40 may be one. Even if the two side lips 36 and 38 come close to each other and the projection 40 contacts the opposite side lip 38, the space inside the two side lips 36 and 38 is not connected to the other side through the portion other than the projection 40. Communicate with the part.

  However, as shown in FIG. 4, it is preferable that a plurality of protrusions 40 be provided discontinuously in the circumferential direction of the side lip 36 (that is, the circumferential direction of the sealing device 20). Due to the discontinuity of the protrusion 40 in the circumferential direction, even if the two side lips 36 and 38 come close to each other and a part of the two lips 36 and 38 come into contact with each other, , 38 communicate with other portions. Further, since the plurality of protrusions 40 are discontinuously provided in the circumferential direction, the contact points between the two side lips 36 and 38 are dispersed as compared with the case where a single protrusion is provided. Variations in the circumferential direction of the contact pressure between both side lips 36 and 38 are reduced.

  Although not limited, it is preferable that the heights h (see FIG. 3) of these protrusions 40 are equal, and it is preferable that the intervals in the circumferential direction of the protrusions 40 are also equal. In these cases, the variation in the circumferential direction of the contact pressure between the side lips 36 and 38 with respect to the hub 4 is further reduced.

Second Embodiment FIG. 8 is an enlarged sectional view of a part of a sealing device according to a second embodiment of the present invention. FIG. 9 is an enlarged cross-sectional view of a part of the sealing device according to the third embodiment of the present invention. FIG. 10 is an enlarged cross-sectional view of a part of the sealing device according to the fourth embodiment of the present invention. In FIG. 8 and the subsequent drawings, the same reference numerals are used to show the components common to the first embodiment, and the components will not be described in detail.

  As shown in FIG. 8, in the second embodiment, a groove 42 is formed in the side lip 36 instead of the protrusion 40. As is clear from comparison with FIG. 6, the groove 42 is disposed at a position where the tip of the side lip 38 can come into contact without the groove 42. Although not shown, a plurality of grooves 42 are provided discontinuously in the circumferential direction of the side lip 36 (that is, the circumferential direction of the sealing device 20).

  Also in the second embodiment, even if the two side lips 36 and 38 are close to each other and a part of them is in contact with each other, the space inside the two side lips 36 and 38 is not connected to the other side via the groove 42. It is easy to separate the two side lips 36, 38 in communication with the part. For this reason, the situation where only one side lip contacts the hub 4 is reduced, and it is possible to suppress an increase in torque applied to the spindle. In addition, since each of the two side lips 36 and 38 is in contact with the hub 4 for a longer period, the function of the side lips 36 and 38 that prevent entry of foreign matter from the outside is appropriately maintained.

  From the above viewpoint, the number of the grooves 42 may be one. Even if the two side lips 36 and 38 come close to each other and the protrusion 40 comes into contact with the opposite side lip 38, the space inside the two side lips 36 and 38 communicates with other parts via the groove 42. To do.

  However, it is preferable that a plurality of the grooves 42 be provided discontinuously in the circumferential direction of the side lip 36 (that is, the circumferential direction of the sealing device 20). Since the groove 42 is discontinuous in the circumferential direction, even if the two side lips 36 and 38 come close to each other and a part of them comes into contact with each other, the gap 42 is interposed between the two side lips 36 and 38. The interior of the space communicates with other parts. Further, by providing a plurality of grooves 42 discontinuously in the circumferential direction, variation in contact pressure between the side lips 36 and 38 with respect to the hub 4 in the circumferential direction is reduced as compared with the case where a single groove is provided. Is done.

  Although not limited, it is preferable that the depths d of these grooves 42 are equal, and it is preferable that the circumferential intervals of the grooves 42 are also equal. In these cases, the variation in the circumferential direction of the contact pressure between the side lips 36 and 38 with respect to the hub 4 is further reduced.

Third Embodiment In the first embodiment, the protrusion 40 is formed on the side lip 36. However, for the same purpose, the side lip 36 is opposed to the tip of the side lip 38 as in the third embodiment shown in FIG. A protrusion 44 may be formed on the surface to be processed.

  For the same reason as described above with respect to the first embodiment, the number of the protrusions 44 may be one, but when a plurality of discontinuities are provided in the circumferential direction of the side lip 38 (that is, the circumferential direction of the sealing device 20). preferable. Moreover, although not limited, it is preferable that the heights h of the plurality of protrusions 44 are equal, and it is preferable that the circumferential intervals of the protrusions 44 are also equal. In these cases, the variation in the circumferential direction of the contact pressure between the side lips 36 and 38 with respect to the hub 4 is further reduced.

Fourth Embodiment In the second embodiment, a groove 42 is formed in the side lip 36. However, for the same purpose, the side lip 36 is opposed to the tip of the side lip 38 as in the fourth embodiment shown in FIG. A groove 46 may be formed on the surface to be processed.

  For the same reason as described above with respect to the second embodiment, the number of the grooves 46 may be one. However, when a plurality of grooves 46 are provided discontinuously in the circumferential direction of the side lip 38 (that is, the circumferential direction of the sealing device 20). preferable. Further, although not limited, the depths d of the plurality of grooves 42 are preferably uniform, and the circumferential intervals of the grooves 42 are also preferably uniform. In these cases, the variation in the circumferential direction of the contact pressure between the side lips 36 and 38 with respect to the hub 4 is further reduced.

Fifth Embodiment FIG. 11 is a partial cross-sectional view of a sealing device 50 according to a fifth embodiment of the present invention. In the sealing device 50 and the sealing device 20 of the first embodiment shown in FIG. 2, the shape and direction of the reinforcing ring 32 are different.

  In the fifth embodiment, the sealing device 50 is used together with a rotary seal member 52 called a slinger. The sealing device 50 and the rotary seal member 52 can also be considered as a combined assembly. The sealing device 50 and the rotary seal member 52 cooperate to prevent the lubricant from flowing out of the hub bearing 1.

  The rotary seal member 52 includes a sleeve 54 that is fixed to the outer peripheral surface of the hub 4 and a flange 56 that is integrally connected to an end portion on the outboard side of the sleeve 54 and radially spreads outward. The method of fixing the hub 4 and the sleeve 54 is not limited, but may be an interference fit, for example.

  The flange 56 has a function of reducing entry of foreign matter from the outboard side. In particular, when the hub 4 rotates, the flange 56 jumps off foreign matter.

  The radial lip 34 of the sealing device 50 contacts the outer peripheral surface of the sleeve 54 of the rotary seal member 52. The radial lip 34 plays a role of mainly preventing the lubricant from flowing out from the inside of the hub bearing 1. The side lips 36, 38 are in contact with the flange 56 of the rotary seal member 52, and play a role of mainly preventing foreign matters from flowing into the hub bearing 1 from the outside as in the first embodiment. In the drawing, the radial lip 34 and the side lips 36 and 38 when the sealing device 50 is not disposed on the hub bearing 1 are shown. At this time, the radial lip 34 and the side lips 36, 38 are not subjected to external force and are in a straight state. However, in reality, when the sealing device 50 is disposed on the hub bearing 1, these lips contact the hub 4 and are deformed by receiving a reaction force.

  Also in the sealing device 50 of the fifth embodiment, as in the first to fourth embodiments, the surface of one side lip facing the other side lip is closely attached to the entire circumferential direction of these two side lips. A protrusion 40 or 44 or a groove 42 or 46 for preventing the above can be formed.

  The sealing device 50 of the fifth embodiment may be used as the sealing device 22 shown in FIG. In this case, the outboard side and the inboard side in FIG. 11 are reversed.

Other Modifications While various embodiments of the present invention have been described above, the above description is not intended to limit the present invention, and various modifications including deletion, addition, and replacement of components are included within the technical scope of the present invention. Variations are possible.

  For example, both the protrusion and the groove may be formed on the side lip 36 or the side lip 38.

  Further, a protrusion may be formed on the side lip 36 and a groove may be formed at a position where the protrusion does not mesh with the protrusion of the side lip 38. Conversely, a protrusion is formed on the side lip 38 and the protrusion does not mesh with the protrusion of the side lip 36. You may form a groove | channel in this. In these cases, since the protrusions that are discontinuous in the circumferential direction can prevent the two side lips 36 and 38 from sticking over the entire circumferential direction, the grooves may be continuous in the circumferential direction.

  The grooves or protrusions described above are not limited to grooves or protrusions that are intentionally formed, and may be unevenness that appears due to the roughness of the surface of the side lip, for example, unevenness due to a satin finish on the surface. .

1 Hub bearing 2 Hole 4 Hub (inner member)
6 Inner ring (inner member)
8 Outer ring (outer member)
10, 12 Balls 14, 15 Cage 16 Hub knuckle 18 Outboard side flange 20, 22, 50 Sealing device 23 Outer peripheral surface 24 Flange surface 25 Arc surface 26 Main annular body (annular body)
30 Elastic ring 32 Reinforcement ring 34 Radial lip 36, 38 Side lip 40, 44 Protrusion 42, 46 Groove 52 Rotating seal member 54 Sleeve 56 Flange

Claims (2)

A sealing device that is disposed between a relatively rotating inner member and an outer member of a rolling bearing and seals a gap between the inner member and the outer member,
An annular body fixed to the outer member;
A radial lip extending radially inward from the annular body;
Two side lips extending side by side from the annular body,
A sealing device, wherein a protrusion or a groove for preventing close contact of the two side lips in the entire circumferential direction is formed on a surface of the one side lip facing the other side lip.   The sealing device according to claim 1, wherein a plurality of the protrusions or the grooves are provided discontinuously in the circumferential direction of the sealing device.

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