JP6417726B2 - Clutch release bearing device - Google Patents

Description

  The present invention relates to an improvement of a clutch release bearing device which is incorporated in a clutch mechanism of a manual transmission for an automobile and used for pressing or pulling a diaphragm spring when performing a shifting operation.

  The clutch mechanism attached to the manual transmission includes a flywheel that rotates together with the crankshaft of the engine, a clutch disk that faces the flywheel, a pressure plate that presses the clutch disk toward the flywheel, and a pressure plate. A diaphragm spring that presses against the clutch disc, and is movable along a power transmission shaft, and the inclination angle of the diaphragm spring is changed with the movement to control the connection / disconnection between the flywheel and the clutch disc. And a clutch release bearing device.

  Conventionally, when the clutch is disengaged as such a clutch mechanism (when the flywheel and the clutch disc are separated so that the rotational force of the crankshaft is not transmitted to the transmission via the shaft), the center of the diaphragm spring A so-called push type that presses the portion and a so-called pull type that pulls the central portion of the diaphragm spring when the clutch is disengaged are used.

  In any clutch mechanism, when the clutch is disengaged, the clutch release bearing device is displaced in the axial direction by a release fork that swings as the clutch pedal is depressed. Then, by engaging any one of the ring rings of the clutch release bearing constituting the clutch release bearing device with the central portion of the diaphragm spring directly or through another member, the central portion of the diaphragm spring Is pressed or pulled. In this state, the clutch release bearing device prevents each portion from sliding and frictioning regardless of the rotation of the diaphragm spring, based on the relative rotation between the one raceway and the other raceway.

3 to 5 show an example of a conventional structure of such a clutch release bearing device. The illustrated clutch release bearing device 1 is incorporated in a push-type clutch mechanism, and includes a clutch release bearing 2 and a bearing holder 3 that holds the clutch release bearing 2.
Of these, the clutch release bearing 2 includes an outer ring 5 that is a stationary ring having a deep groove type outer ring raceway 4 on an inner peripheral surface, and an inner ring 7 that is a rotating ring having an angular inner ring raceway 6 on an outer peripheral surface. The ball bearing includes a plurality of balls 8 and 8 provided between the outer ring raceway 4 and the inner ring raceway 6 so as to be freely rollable, and a pair of seal rings 9a and 9b. Thus, in the illustrated example, the outer ring raceway 4 is a deep groove type and the inner ring raceway 6 is an angular type. For this reason, the clutch release bearing 2 can support the rightward thrust load of FIG. 3 in addition to the radial load. The inner ring 7 is formed by pressing a steel plate, and one end portion in the axial direction (left end portion in FIG. 3) protrudes from the inner diameter side of the outer ring 5 in the axial direction, and the tip edge thereof. Is bent radially outward to form a pressing portion 10 for pressing a central portion of a diaphragm spring (not shown). The other end surface in the axial direction of the inner ring 7 (the right end surface in FIG. 3) is located on one side in the axial direction with respect to the other end surface in the axial direction of the outer ring 5.

  Each of the seal rings 9a and 9b is engaged with locking grooves 11 and 11 formed at both ends in the axial direction of the inner peripheral surface of the outer ring 5 at the outer peripheral edges thereof. In addition, contact lips 12a and 12b and non-contact lips 13a and 13b are provided at the inner diameter side ends of the seal rings 9a and 9b, respectively. Yes. Of the two seal rings 9a and 9b, with respect to the seal ring 9a on the other side in the axial direction (rear side, right side in FIGS. 3 and 5), the tip edge of the contact lip 12a provided on the inner peripheral edge is connected to the inner ring 7. The other end surface in the axial direction of the inner ring 7 is brought into contact with the entire circumference, and the leading edge of the non-contact lip 13a is closely opposed to the outer circumferential surface of the other end portion in the axial direction of the inner ring 7 over the entire circumference. On the other hand, regarding the seal ring 9b on one axial side (front side, left side in FIGS. 3 and 5) of the seal rings 9a and 9b, the tip edge of the contact lip 12b provided on the inner peripheral edge is The outer periphery of the inner ring 7 is in contact with the outer circumferential surface of the intermediate portion in the axial direction, and the tip edge of the non-contact lip 13b is closely opposed to the outer circumferential surface of the inner ring 7 in the axial direction of the intermediate portion.

The bearing holder 3 is constituted by combining a resin molded body 14, a pair of holding springs 15 and 15, and an anvil 16.
Of these, the resin molded body 14 is made of a slippery synthetic resin and is formed in an annular shape as a whole. Such a resin molded body 14 includes a cylindrical sleeve 17 that is externally fitted to a guide shaft (not shown) disposed in the axial direction of the diaphragm spring so as to be movable along the guide shaft, and the sleeve. An annular flange portion 18 provided in a state of projecting radially outward from the outer peripheral surface of the intermediate portion 17 and two positions on the radially opposite side of the outer peripheral edge of the flange portion 18, respectively in the axial direction, etc. A pair of guide plate portions 19, 19 extending in parallel to each other are provided. The side surfaces of the two guide plate portions 19 and 19 that are opposed to each other are used as guide surfaces for guiding the tip of a release fork (not shown).

  Further, the pair of holding springs 15 and 15 are made of a metal plate having sufficient elasticity. The clutch release bearing 2 has one axial side surface of the flange portion 18 (on the left side in FIGS. 3 and 5) by the holding springs 15 and 15 assembled at two positions on the opposite side in the radial direction of the flange portion 18. Surface) is supported so as to be slightly displaceable in the radial direction. The reason why the clutch release bearing 2 is supported on the one side surface in the axial direction of the flange portion 18 so as to be slightly displaceable in the radial direction in this way is to allow the clutch release bearing 2 to have self-alignment with respect to the diaphragm spring. It is.

  As described above, in the state where the clutch release bearing 2 is supported by the bearing holder 3 (flange portion 18), the other axial end surface of the outer ring 5 of the clutch release bearing 2 (the right end surface in FIGS. 3 and 5). Is in contact with one side surface of the flange portion 18 in the axial direction. On the other hand, an axial clearance space 20 exists between the other axial end surface of the inner ring 7 and the other axial side surface of the seal ring 9 a on the other axial side, and one axial side surface of the flange portion 18. ing. The radially outer end portion of the axial clearance space 20 is blocked by a contact portion between the other axial end surface of the outer ring 5 and one axial side surface of the flange portion 18, and the radially inner end portion is It continues to the other axial end of a radial gap space 21 to be described later. Further, a radial clearance space 21 exists between the inner peripheral surface of the inner ring 7 and the outer peripheral surface of the half piece axial portion of the sleeve 17 facing the inner peripheral surface. One end portion in the axial direction of the radial clearance space 21 is open, and the other end portion in the axial direction is continuous with the radially inner end portion of the axial clearance space 20.

  The anvil 16 is made of a metal plate having sufficient rigidity, and is attached to the other axial side surface (the right side surface in FIG. 3) of the flange portion 18. The side surface (the right side surface in FIG. 3) opposite to the flange portion 18 of the anvil 16 is used as a pressed surface that is pressed by the distal end portion of the release fork.

  When the clutch release bearing device 1 configured as described above is assembled to the push-type clutch mechanism described above, the clutch release bearing device 1 is disposed between the center portion of the diaphragm spring and the tip portion of the release fork. The sleeve 17 is externally fitted to the guide shaft so as to be movable along the guide shaft. In this state, when the driver steps on the clutch pedal to perform a shifting operation, the side of the anvil 16 is pressed by the tip of the release fork as the release fork swings. As a result, the clutch release bearing device 1 moves to the diaphragm spring side along the guide shaft, and the front end surface of the pressing portion 10 comes into contact with the central portion of the diaphragm spring. The center part of the diaphragm spring is pressed. As a result, the clutch is disconnected based on the operation of a known mechanism.

  By the way, with the improvement of engine performance in recent years, the amount of heat generated by the engine tends to increase. For this reason, in order to prevent temperature rise around the engine, it is considered to provide a cooling air hole in the clutch housing covering the clutch device (see, for example, Patent Document 1). However, when such an air hole is provided, foreign matter typified by muddy water may enter from the outside through this air hole, and the clutch release bearing device disposed in the clutch housing may be muddy water or the like. May be exposed to foreign objects. For this reason, the request | requirement with respect to the sealing performance improvement of the clutch release bearing which comprises a clutch release bearing apparatus is increasing.

  Accordingly, the present inventors have conducted numerous experiments in order to clarify the intrusion route of muddy water into the clutch release bearing before the present invention is completed. As a result, as shown by an arrow α in FIG. 5, the muddy water is released from the clutch release in the use state in the radial clearance space 21 existing between the outer peripheral surface of the sleeve 17 and the inner peripheral surface of the inner ring 7. It turned out that it penetrate | invades in the part located in the lower end of the bearing apparatus 1. FIG. Then, the muddy water stays in the axial gap space 20 between the seal ring 9a on the other side in the axial direction and the flange portion 18, and as shown in the figure, when the water level becomes high, the contact lip 12a and the inner ring 7 Since the sliding contact portion 22 with the other axial end surface is immersed in the muddy water, it has been found that the muddy water easily enters the inside of the clutch release bearing 2 through the sliding contact portion 22.

  Based on the above experimental results, it is effective to improve the sealing performance of the clutch release bearing 2 to improve the sealing performance (muddy water resistance) of the seal ring 9a on the other side in the axial direction. Therefore, it is conceivable to increase the tightening margin of the contact lip 12a constituting the seal ring 9a. In this case, although the sealing performance can be improved, the starting torque and the rotational torque of the clutch release bearing 2 are excessive. This creates a new problem. It is also possible to add a seal ring to improve the sealing performance. In this case, however, the clutch release bearing 2 has increased bearing dimensions, weight, number of parts, and cost. It will cause problems.

JP 2001-280367 A

  In view of the circumstances as described above, the present invention can suppress an increase in starting torque and rotational torque, and can improve sealing performance without increasing any of bearing size, weight, number of parts, and cost. A release bearing device is realized.

The clutch release bearing device of the present invention includes a bearing holder and a clutch release bearing.
Of these, the bearing holder includes a cylindrical sleeve slidable along the shaft, and an annular flange projecting radially outward from the outer peripheral surface of the sleeve.
The clutch release bearing is supported on one axial side of the flange portion. Such a clutch release bearing can freely roll between an outer ring that is a stationary ring having an outer ring raceway on an inner peripheral surface, an inner ring that is a rotating ring having an inner ring raceway on an outer peripheral surface, and the outer ring raceway and the inner ring raceway. A plurality of rolling elements (for example, balls or rollers) provided on the outer ring, and outer peripheral edge portions of the outer ring are engaged with inner peripheral surfaces of both axial ends of the outer ring, and an inner peripheral surface of the outer ring and an outer peripheral surface of the inner ring And a pair of seal rings that closes both ends in the axial direction of the rolling element installation space between which the rolling elements are installed.

In particular, in the case of the clutch release bearing device of the present invention, of the two seal rings , the radially inner end of the seal ring on the other axial side opposite to the flange portion is radially inward. The lip base that is inclined in the direction toward one side in the axial direction as it goes, and the inner edge of the lip base extend from the inner peripheral edge , and the tip edge thereof is slidably contacted with the outer peripheral surface of the other end in the axial direction of the inner ring over the entire circumference. and a contact lip is provided was.
Further, of the one side surface in the axial direction of the flange portion, the portion located at the lower end in use is between the one side surface in the axial direction of the flange portion and the other side surface in the axial direction of the seal ring on the other side in the axial direction. A substantially L-shaped drainage ditch is provided that communicates between the gap space that is formed and an external space that exists radially outward (downward) of the outer ring.
Further, when carrying out the present invention, preferably, as in the invention described in claim 2, it extends from the inner peripheral edge of the lip base , and its tip edge is on the outer peripheral surface of the other end in the axial direction of the inner ring. A non-contact lip is provided that is closely opposed over the entire circumference.

When the present invention is carried out, it is preferable that, as in the invention described in claim 3 , of the two seal rings, the outer side of the seal ring on one axial side that does not face the flange portion in the axial direction. A locking portion for locking to the inner peripheral surface of one end portion in the axial direction of the outer ring is formed on the peripheral edge, and in the other axial end portion of the outer ring on the outer peripheral edge portion of the seal ring on the other side in the axial direction . A locking portion for locking to the peripheral surface is formed. Then, before the Kiten body installation space and the through-hole communicating with the outside space, the shaft without forming the engaging portion in a direction other side of the seal ring, the locking portion of the axial one side of the seal ring Form .

According to the present invention having the above-described configuration, a clutch release bearing that can suppress an increase in rotational torque and can improve sealing performance without increasing any of the bearing size, weight, number of parts, and cost. A device can be realized.
That is, in the case of the present invention, of a pair of seal rings that closes both axial opening portions of the rolling element installation space, the inner diameter side end of the seal ring on the other axial side facing the flange portion in the axial direction. The tip edge of the contact lip provided in the portion is in sliding contact with the outer peripheral surface of the other end in the axial direction of the inner ring. Therefore, likely to become entry pathway of mud present in the interstitial spaces in the axial direction the other side of the seal ring of the axially other side, the sliding contact portion between the inner ring and the axial direction other side of the seal ring, FIG. 5 Compared with the conventional structure shown in (1), the muddy water can be arranged at a position where it is difficult to enter the rolling element installation space (a position where muddy water is difficult to directly hit). As a result, the sealing performance higher than that of the conventional structure can be obtained without increasing the contact margin of the contact lip, so that the starting torque and rotational torque of the clutch release bearing do not increase. Further, since the sealing performance can be improved without newly providing other members (such as a seal ring), the bearing size, weight, number of parts, and cost are not increased.
In addition, according to the present invention, foreign matter that has entered the gap space can be discharged into the external space (downward) without being retained by the drainage ditch formed on one side surface in the axial direction of the flange portion. Therefore, as in the conventional structure shown in FIG. 5, the sliding contact portion between the tip edge of the contact lip and the other axial end surface of the inner ring is immersed in the foreign matter as the water level of the foreign matter rises. Can be effectively prevented. Therefore, the sealing performance of the release bearing can be further improved.

In the case of the present invention, the labyrinth is provided between the non-contact lip and the inner ring by providing the non-contact lip in addition to the contact lip on the seal ring on the other side in the axial direction. A seal can be formed. For this reason, it can prevent more effectively that muddy water etc. penetrate | invade in the said rolling-element installation space, without the starting torque and rotational torque of a clutch release bearing rising .
Further, in the case of the invention described in claim 3, the locking portion formed on the outer peripheral edge of the seal ring of the axial other side, forming a through-hole communicating with the said rolling element installation space outside space It is configured not to. For this reason, mud etc. do not penetrate | invade in the said rolling element installation space through a through-hole.

Sectional drawing of the part located in a lower end part in use condition which shows the 1st example of embodiment of this invention. The figure similar to FIG. 1 which shows the 2nd example. FIG. 5 is a cross-sectional view taken along the line B-OB in FIG. The figure seen from the right side of FIG. Similarly the expanded sectional view of the part located in a lower end part in use condition.

[First example of embodiment]
A first example of the embodiment of the present invention will be described with reference to FIG. The feature of this example is the structure of the seal ring 23 arranged on the other side in the axial direction (the right side and the rear side in FIG. 1) of the clutch release bearing 2a constituting the clutch release bearing device 1a, and the bearing holder. It is in the structure of the flange part 18a which comprises 3a. The structure and operational effects of the other parts are basically the same as those of the conventional structure shown in FIGS. For this reason, the description and illustration of the overlapping parts are omitted or simplified, and hereinafter, the characteristic part of this example and the part not described above will be mainly described. In addition, about each example of embodiment including this example, although it demonstrates for the muddy water which is a typical foreign material, it does not exclude including other foreign materials other than a muddy water.

  The clutch release bearing 2a of the present example is also supported on one side (left side in FIG. 1) of the annular flange portion 18a constituting the bearing holder 3a, and includes an outer ring 5, an inner ring 7, and a plurality of balls. 8, a cage 24, and a pair of seal rings 23 and 9 b. Of these, the outer ring 5 is a stationary ring having a deep groove type outer ring raceway 4 on the inner peripheral surface, and a pair of locking grooves 25a and 25b are formed on the inner peripheral surface of both end portions in the axial direction over the entire periphery. The inner ring 7 is a rotating wheel having an angular inner ring raceway 6 on the outer peripheral surface. Each ball 8 is provided between the outer ring raceway 4 and the inner ring raceway 6 so as to be able to roll while being held by the cage 24.

  Both the seal rings 23, 9b are present between the inner peripheral surface of the outer ring 5 and the outer peripheral surface of the inner ring 7, and close both ends in the axial direction of the rolling element installation space 26 in which the balls 8 are installed. It is out. Among such seal rings 23 and 9b, the seal ring 23 on the other axial side (rear side) arranged in a state facing the one axial side surface of the flange portion 18a in the axial direction is a metal such as a steel plate. A cored bar 27 formed by forming a plate into an annular shape, and a sealing material 28 made of an elastic material such as an elastomer such as rubber, which is integrally coupled to the cored bar 27, are provided. A locking portion 29 provided at a portion projecting radially outward (downward in FIG. 1) from the outer peripheral edge portion of the core metal 27 at the outer peripheral edge portion of the sealing material 28 is provided on the shaft of the outer ring 5. It is locked in a locking groove 25a formed on the inner peripheral surface of the other end in the direction. Further, a portion of the sealing material 28 that protrudes radially inward (upward in FIG. 1) from the inner peripheral edge of the cored bar 27 has a lip base 30, a non-contact lip 31, and a contact lip 32. Are formed.

Of these, the lip base portion 30 is formed so as to be inclined from the inner peripheral edge portion of the cored bar 27 in a direction toward one axial side as it goes radially inward. In this way, of the axial clearance space 20 existing between the one axial side surface of the flange portion 18a and the other axial end surface of the outer ring 5 and the other axial side surface of the seal ring 23, the usage state Thus, the muddy water that has entered the portion located at the lower end of the clutch release bearing device 1a (the portion above the lip base portion 30) is easily guided downward (to the drainage ditch 40 described later).
The non-contact lip 31 is formed on the inner peripheral edge of the lip base 30 so as to be inclined in a direction toward one axial side as it goes radially inward from the inner peripheral edge. The leading edge (inner peripheral edge) of the non-contact lip 31 is made to face and oppose the outer peripheral surface of the other end in the axial direction of the inner ring 7 over the entire periphery, and a labyrinth seal 33 is formed at that portion.

  The contact lip 32 is formed in a substantially triangular cross section in a state of extending from the inner peripheral edge portion of the lip base portion 30 (the radially outer end portion of the non-contact lip 31) to the other axial direction. The inner peripheral edge of the contact lip 32 is more axial than the portion of the outer peripheral surface of the other end portion in the axial direction of the inner ring 7 where the non-contact lip 31 is closely opposed (portion where the labyrinth seal 33 is formed). The other side of the direction (the side opposite to the rolling element installation space 26) is slid over the entire circumference. The size of the fastening margin of the contact lip 32 is the same as that of the conventional structure shown in FIGS.

  On the other hand, the seal ring 9b on one axial side (front side) is made of a cored bar 34 formed by forming a metal plate such as a steel plate into an annular shape, and an elastic material such as an elastomer such as rubber that is integrally coupled to the cored bar 34. And a sealing material 35 made of a material. Then, an engaging portion 36 provided at a portion projecting radially outward from the outer peripheral edge portion of the core metal 34 at the outer peripheral edge portion of the sealing material 35 is provided on the inner peripheral surface of one end portion in the axial direction of the outer ring 5. It is locked in the formed locking groove 25b. Further, a contact lip 12b and a non-contact lip 13b are respectively formed at the inner diameter side end portion of the sealing material 35 at a portion protruding radially inward from the inner peripheral edge portion of the cored bar 34. . Of these, the tip edge of the contact lip 12b is brought into contact with the outer peripheral surface of the axially intermediate portion of the inner ring 7 over the entire circumference, and the non-contact lip 13b disposed on one axial side of the contact lip 12b. The tip edge of the inner ring 7 is opposed to the outer peripheral surface of the intermediate portion in the axial direction over the entire circumference. In the case of this example, the rolling element installation space 26 in which the balls 8 are installed and the external space 37 existing around the clutch release bearing 2a are communicated with the locking portion 36, and this rolling part 36 is connected. One or more air holes 38 are formed to prevent the internal pressure of the moving body installation space 26 from increasing. In addition, such an air hole is not formed in the latching | locking part 29 which comprises the said seal ring 23 of the axial direction other side (rear side).

Further, in the case of this example, of the inner peripheral surface of the cover portion 39 provided in a state of projecting toward one axial side from the outer peripheral edge portion of the flange portion 18a and the outer peripheral edge portion of the flange portion 18a. The axial gap space 20 existing between the one axial side surface of the flange portion 18a and the other axial side surface of the seal ring 23 and the external space 37 are communicated with a portion located at the lower end in use. A substantially L-shaped drainage ditch 40 is formed. The radially inner end of the drainage ditch 40 has a position facing the outer diameter side portion of the seal ring 23 in the axial direction (a position radially inward of the other end surface in the axial direction of the outer ring 5). It opens to the space 20.
Since the clutch release bearing device can be mounted in a state of being rotated 180 degrees with respect to the guide shaft, the drainage recess is improved in order to improve the assembly property of the clutch release bearing device (to prevent assembly errors). The grooves 40 may be provided at two positions (upper and lower ends in use) on the opposite side in the diameter direction of the flange portion 18a and the cover portion 39.

  According to the clutch release bearing device 1a of the present example having the above-described configuration, with respect to the clutch release bearing 2a constituting the clutch release bearing device 1a, an increase in rotational torque can be suppressed and the bearing size, weight, and number of parts can be reduced. The sealing performance can be improved without increasing both the cost and the cost.

That is, in the case of this example, the tip edge of the contact lip 32 provided at the inner diameter side end of the seal ring 23 on the other axial side constituting the clutch release bearing 2a is used as the other axial end of the inner ring 7. It is in sliding contact with the outer peripheral surface of the part. For this reason, the foreign matter is used as the sliding contact portion 22 a between the seal ring 23 and the inner ring 7, which tends to be an entry path for foreign matters such as muddy water existing in the axial gap space 20 during use. Can be disposed at a position where it is difficult to enter (a position where muddy water entering the axial gap space 20 is difficult to directly contact). As a result, even if the tightening margin of the contact lip 32 is not increased, a sealing performance higher than that of the conventional structure shown in FIG. 5 can be obtained, so that the starting torque and rotational torque of the clutch release bearing 2a are increased. There is nothing. Further, since the sealing performance can be improved without newly providing other members (such as a seal ring), the bearing size, weight, number of parts, and cost are not increased.

  Further, in the case of this example, in addition to the contact lip 32, the non-contact lip 31 is provided on the seal ring 23, so that the seal ring 23 and the inner ring 7 are more slidable than the sliding contact portion 22a. The labyrinth seal 33 can be formed on the rolling element installation space 26 side. For this reason, it can prevent more effectively that foreign materials, such as muddy water, penetrate | invade into the said rolling element installation space 26. FIG.

  Furthermore, in the case of this example, the muddy water that has entered the axial gap space 20 is removed by the drainage ditch 40 formed in a range extending over one axial side surface of the flange portion 18a and the inner peripheral surface of the cover portion 39. Without being retained in the axial gap space 20, it can be discharged to the external space 37. For this reason, it is possible to effectively prevent the sliding contact portion 22a between the seal ring 23 and the inner ring 7 from being immersed in the muddy water as the muddy water level rises.

As described above, in the case of this example, the structure of the contact lip 32 constituting the seal ring 23 is devised, and the drainage is disposed on one axial side surface of the flange portion 18a and the inner peripheral surface of the cover portion 39. By forming the concave groove 40, the sealing performance of the clutch release bearing 2a can be improved.
In addition, in the case of this example, in order to improve the sealing performance in this way, it is not necessary to change the size of the tightening margin of the contact lip 32, so that the starting torque and rotational torque of the clutch release bearing 2a are increased. There is nothing to do. Further, since no new seal ring is provided, the bearing size, weight, number of parts, and cost are not increased.
Other configurations and operational effects are the same as those of the conventional structure described above.

[Second Example of Embodiment]
A second example of the embodiment of the present invention will be described with reference to FIG. The feature of this example is that the arrangement relationship in the axial direction between the non-contact lip 31a and the contact lip 32a constituting the seal ring 23a is opposite to that in the first example of the embodiment described above.
Specifically, in the case of the clutch release bearing device 1b of the present example, the non-contact lip 31a is directed radially inward from the inner peripheral edge of the lip base 30 (the other axial end of the contact lip 32a described later). It is formed in a state inclined in the direction toward the other axial direction. The leading edge (inner peripheral edge) of the non-contact lip 31a is made to face and oppose the outer peripheral surface of the other end portion in the axial direction of the inner ring 7 over the entire periphery, and a labyrinth seal 33a is formed at that portion.

  On the other hand, the contact lip 32a is formed on the inner peripheral edge of the lip base 30 so as to have a substantially triangular cross section in a state extending from the inner peripheral edge to one axial direction. Then, the inner peripheral edge of the contact lip 32a is more axial than the portion of the outer peripheral surface of the other end portion in the axial direction of the inner ring 7 where the non-contact lip 31a is closely opposed (portion where the labyrinth seal 33a is formed). One side of the direction (the rolling element installation space 26 side) is in sliding contact with the entire circumference. The size of the fastening margin of the contact lip 32a is the same as that of the conventional structure shown in FIGS. 3 to 5 and the first example of the embodiment described above.

  In the case of this example having the above-described configuration, the non-contact lip 31a is provided on the other side in the axial direction (opposite to the rolling element installation space 26) than the contact lip 32a. The labyrinth seal 33 can be formed on the other axial side of the sliding contact portion 22b with the inner ring 7. For this reason, it is possible to effectively prevent foreign matters such as muddy water from reaching the sliding contact portion 22b. About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment.

When implementing the present invention, the shapes of the contact lip and the non-contact lip are not limited to the illustrated structure, and various shapes can be adopted. Further, the position and shape of the drainage ditch are not limited to the structure shown in the figure, and can be changed as appropriate. Deviate from the scope of the present invention, the drainage groove, the inner peripheral surface of the cover portion is not formed, may be formed only on one axial side surface of the flange portion.

DESCRIPTION OF SYMBOLS 1, 1a, 1b Clutch release bearing device 2, 2a Clutch release bearing 3, 3a Bearing holder 4 Outer ring raceway 5 Outer ring 6 Inner ring raceway 7 Inner ring 8 Ball 9a, 9b Seal ring 10 Pressing part 11 Locking groove 12a, 12b Contact lip 13a, 13b Non-contact lip 14 Resin molded body 15 Holding spring 16 Anvil 17 Sleeve 18, 18a Flange 19 Guide plate 20 Axial clearance space 21 Radial clearance space 22, 22a, 22b Sliding contact 23, 23a Seal ring 24 Cage 25a, 25b Locking groove 26 Rolling element installation space 27 Core metal 28 Sealing material 29 Locking portion 30 Lip base 31, 31a Non-contact lip 32, 32a Contact lip 33, 33a Labyrinth seal 34 Core metal 35 Sealing material 36 Engagement Stop part 37 External space 38 Air hole 39 Cover part 4 Drainage groove

Claims (3)

A bearing holder having a cylindrical sleeve slidable along the shaft, and an annular flange provided in a state of projecting radially outward from the outer peripheral surface of the sleeve, and a shaft of the flange A clutch release bearing supported on one side of the direction,
This clutch release bearing is provided between an outer ring, which is a stationary ring having an outer ring raceway on an inner peripheral surface, an inner ring, which is a rotating ring having an inner ring raceway on an outer peripheral surface, and the outer ring raceway and the inner ring raceway. The outer peripheral edge portions of the plurality of rolling elements and the inner peripheral surfaces of both end portions in the axial direction of the outer ring are locked, and each of the rolling elements exists between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. A clutch release bearing device comprising a pair of seal rings that close both axial opening portions of the rolling element installation space in which
Of the two seal rings, the lip base portion that is inclined in the direction toward one axial side toward the inner side in the radial direction at the inner diameter side end of the seal ring on the other axial side opposite to the flange portion in the axial direction. And a contact lip extending from the inner peripheral edge of the lip base and having its tip edge slidably contacted with the outer peripheral surface of the other end in the axial direction of the inner ring over the entire circumference ,
A gap that exists between the one axial side surface of the flange portion and the other axial side surface of the seal ring on the other side in the axial direction at a portion located at the lower end in the use state on one side surface of the flange portion. A clutch release bearing device, characterized in that a substantially L-shaped drainage ditch is formed to communicate the space and an external space existing radially outward of the outer ring . 2. The clutch according to claim 1, wherein a non-contact lip is provided that extends from an inner peripheral edge of the lip base and has a tip edge thereof closely opposed to the outer peripheral surface of the other end in the axial direction of the inner ring over the entire circumference. Release bearing device. A locking portion for locking to the inner peripheral surface of one end portion in the axial direction of the outer ring is formed on the outer peripheral edge of the seal ring on one side in the axial direction that does not face the flange portion in the axial direction, of the two seal rings. A locking portion for locking to the inner peripheral surface of the other end in the axial direction of the outer ring is formed on the outer peripheral edge of the seal ring on the other side in the axial direction ,
Before Kiten body installation space and the through hole communicating with the external space, wherein the shaft is not formed on the engagement portion of the direction the other side of the seal ring, the locking portion of the axial one side of the seal ring clutch release bearing device according to any one of the being formed, it claims 1-2 in.

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