JP2015232362A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of static leakage and suppress an increase of torque even if a seal lip is added in order to suppress the static leakage, in a sealing device which is formed by combining a slinger and a lip seal member.SOLUTION: There is arranged a static leakage suppression lip which suppresses that a sealed fluid leaks to the outside of a machine along a screw groove at a rotation stop of a rotating shaft. The static leakage suppression lip is a rotation-side lip which is held by a slinger and is in tight contact with a lip seal member. The static leakage suppression lip is joined to an external peripheral face of a cylindrical part in the slinger. Furthermore, the static leakage suppression lip comes into tight contact with the lip seal member at the rotation stop of the rotating shaft, and the static leakage suppression lip is elastically deformed by a centrifugal force and separated from the lip seal member at the rotation of the rotating shaft.

Description

  The present invention is a sealing device that prevents a fluid to be sealed in a machine from leaking out of the machine in an automobile, a general machine, an industrial machine, etc., and has a structure in which a non-rotating seal lip is slidably contacted to a rotary seal flange It is related with what comprises. The sealing device of the present invention is used, for example, as an oil seal for rotation that seals in-machine oil in the field of automobiles.

  Conventionally, as shown in FIGS. 6 (A) and 6 (B), the sealing fluid (oil) on the machine inner side A is between the housing 51 and the rotary shaft 61 inserted through the shaft hole 52 provided in the housing 51. A sealing device 101 that seals against leakage to the outside, and is formed by a combination of a slinger 111 mounted on the outer periphery of the rotary shaft 61 and a lip seal member 121 mounted on the inner periphery of the shaft hole 52 of the housing 51. It has been known.

  The slinger 111 is made of a rigid material such as metal, and integrally includes a sleeve portion 112 fixed to the outer peripheral surface of the rotary shaft 61 and a flange portion 113 provided at one end of the sleeve portion 112. A thread groove 114 that exhibits a pumping action by centrifugal force when the rotary shaft 61 rotates is provided on the machine end face 113a of the portion 113.

  On the other hand, the lip seal member 121 includes a mounting ring 122 fixed to the inner peripheral surface of the shaft hole 52 of the housing 51, and a rubber-like elastic body 123 attached to the mounting ring 122. 123, a seal lip (end surface lip) 124 that is slidably in close contact with the machine-side end surface 113a of the flange portion 113 of the slinger 111 is provided.

  By the way, in recent years, the development of fuel-efficient vehicles has been accelerated in the automobile industry due to environmental problems, and needs for engine oil seals include reduction of torque during rotation. Under such circumstances, the end face lip structure of FIG. According to the sealing device 101, a torque reduction of about 60% can be realized as compared with a general radial lip structure sealing device.

Japanese Utility Model Publication No. 3-57563 JP-A-2-113173

  However, for the sealing device 101 of FIG. 6 described above, further functional improvements are required for the following points.

  That is, in the sealing device 101, when the rotary shaft 61 rotates, the slinger 111 rotating together with the rotary shaft 61 exerts a fluid swinging action by the flange portion 113 and a fluid pumping action by the thread groove 114, thereby suppressing leakage of the sealing fluid. However, since the centrifugal force disappears when the rotation of the rotary shaft 61 stops, the sealing fluid may pass through the screw groove 114 and pass through the tip of the seal lip 124 and leak to the outside B. (Possibility of occurrence of so-called stationary leakage). This static leakage occurs when, for example, the vehicle is tilted on a slope and the vehicle body is inclined, and the amount of oil (oil level) in the shaft hole 52 of the engine exceeds the lower end 61a of the rotating shaft 61. It is especially likely to occur.

  In view of the above points, the present invention aims to provide a sealing device that can suppress the occurrence of static leakage in a sealing device that is a combination of a slinger and a lip seal member. It is an object of the present invention to provide a sealing device that can suppress an increase in torque even if a seal lip is added to suppress this.

In order to achieve the above object, the present invention employs the following means.
The sealing device of the present invention is a sealing device that seals a sealing fluid inside the machine from leaking to the outside of the machine between a housing and a rotary shaft that is inserted into a shaft hole provided in the housing. And a lip seal member attached to the inner periphery of the shaft hole of the housing, wherein the slinger is fixed to the outer peripheral surface of the rotating shaft, and one end of the sleeve portion. A flange portion provided on the outer peripheral surface of the flange portion, and a screw groove is provided on the outer end surface of the flange portion, and the lip seal member is fixed to the inner peripheral surface of the shaft hole of the housing; A sealing device provided with a seal lip that contacts the outer end surface of the flange portion of the slinger by the rubber-like elastic body. The stationary leakage suppression lip is provided to prevent the sealing fluid from leaking to the outside of the machine through the thread groove when the rotation shaft stops rotating, and the stationary leakage suppression lip is held by the slinger. The rotating lip is in close contact with the lip seal member (claim 1).

  According to the sealing device of the present invention, since a thread groove is provided on the machine outer end face of the flange portion of the slinger and the seal lip contacts the machine outer end face, there is a concern that stationary leakage may occur when the rotation of the rotary shaft is stopped. However, since there is a static leak suppression lip that is held by the slinger and is in close contact with the lip seal member, this static leak suppression lip exhibits a sealing action, thereby suppressing the occurrence of static leaks. It becomes possible to do.

  The stationary leak suppressing lip is a lip on the rotating side that is held by the slinger and is in close contact with the lip seal member. Therefore, the lip seal member is provided as a lip dedicated for static leakage suppression, separately from the stationary lip (non-rotating side) seal lip provided on the lip seal member.

In order to achieve the above object, the present invention may further employ the following means.
In the sealing device (Claim 1), the static leakage suppression lip is joined to an outer peripheral surface of the sleeve portion of the slinger (Claim 2).

  According to the sealing device of the present invention (Claim 2), the stationary leak suppression lip is attached to the outer periphery of the rotating shaft and joined to the outer peripheral surface of the sleeve portion located immediately below the lower end of the rotating shaft. The height position at which the leakage suppression lip portion is provided is a high position that can easily cope with a high water level (high oil level). This effectively suppresses the occurrence of static leakage even when the vehicle is tilted, for example, when the vehicle stops on a slope, and the amount of oil in the shaft hole of the engine exceeds the lower end of the rotating shaft. Is possible.

  In the sealing device (Claim 1 or 2), the lip for static leakage suppression is in close contact with the lip seal member when the rotation shaft is stopped, and is elastically deformed by centrifugal force when the rotation shaft is rotated. It is separated from the lip seal member (Claim 3).

  According to the sealing device of the present invention (Claim 3), if a static leakage suppression lip is provided separately from the seal lip provided on the lip seal member, there is a concern that the sliding torque of the entire sealing device increases during rotation. Is done. However, as a result, the stationary leak suppressing lip is elastically deformed by centrifugal force during rotation and is separated from the lip seal member, and the rotation torque becomes non-contact with the lip seal member during rotation. It becomes possible to suppress. The static leak suppression lip is a lip dedicated for static leak suppression. Since the static leak occurs when the rotating shaft is stationary, it can sufficiently fulfill its role as non-contact at the time of rotation.

  The present invention has the following effects.

  As described above, since the static leak suppression lip that is held by the slinger and is in close contact with the lip seal member is provided, it is possible to suppress the occurrence of static leak by the sealing action exhibited by the static leak suppression lip. can do. In addition, since the height position in the shaft hole is set high by joining the static leak suppressing lip to the outer peripheral surface of the sleeve portion of the slinger, it is possible to suppress static leak more effectively. In addition, when the stationary leak suppression lip is elastically deformed by centrifugal force during rotation and separated from the lip seal member, an increase in sliding torque can be suppressed even if a static leak suppression lip is provided. .

It is principal part sectional drawing which shows the state at the time of the shaft rotation stop of the sealing device which concerns on 1st Example of this invention. It is explanatory drawing of the thread groove with which the sealing device is equipped. It is principal part sectional drawing which shows the state at the time of the shaft rotation of the sealing device. It is principal part sectional drawing which shows the state at the time of the shaft rotation stop of the sealing device which concerns on 2nd Example of this invention. It is principal part sectional drawing which shows the state at the time of the shaft rotation of the sealing device. It is a figure which shows a prior art example, (A) is principal part sectional drawing of the sealing device which concerns on a prior art example, (B) is explanatory drawing of the screw groove with which the sealing device is equipped.

The present invention includes the following embodiments.
(1) An oil leakage prevention lip (static leakage suppression lip) is joined (vulcanized) to the slinger (rotating side).
(2) According to this configuration, the oil leakage prevention lip is pressed against the oil recovery lip or the like by the reaction force (tightening allowance) of the oil leakage prevention lip made of an elastic body, so that the sealing performance is secured and maintained even when stationary. be able to. Also, during the rotation, oil leaking from the main lip can be collected due to the thread groove of the slinger and the swing-off effect. In addition, by reducing the rigidity of the base of the oil leakage prevention lip joined to the slinger, a clearance is generated between the oil recovery lip and the oil leakage prevention lip due to the centrifugal force of rotation, thereby preventing an increase in friction. (FIG. 3). As for the oil leakage prevention lip to be joined to the slinger, the sealing property at the time of stationary can be ensured even if it is disposed on the atmosphere side (FIGS. 4 to 5).

  Next, embodiments of the present invention will be described with reference to the drawings.

First embodiment
FIG. 1 shows a cross section of a main part of a sealing device 1 according to an embodiment of the present invention.

  In the sealing device 1 according to this embodiment, the sealing fluid (oil) on the machine inner side (oil side) A is between the housing (seal housing) 51 and the rotating shaft 61 inserted through the shaft hole 52 provided in the housing 51. A sealing device (engine oil seal) 1 for sealing so as not to leak to the outside (atmosphere side) B of the machine, attached to the outer periphery of the rotary shaft 61 and the inner periphery of the shaft hole 52 of the housing 51 The lip seal member 21 is used in combination.

  The slinger 11 is made of a rigid material such as metal and has a sleeve portion 12 fixed (fitted) to the outer peripheral surface of the rotary shaft 61 and a flange provided at one end of the sleeve portion 12 (an inner end portion). 2 and the end portion 13a of the flange portion 13 in the annular region indicated by the symbol d in FIG. 1, due to centrifugal force when the rotating shaft 61 is rotated as shown in FIG. A thread groove 14 is provided that exerts an action of pushing back the sealing fluid toward the outer peripheral side (machine inner side A) by exerting a pumping action. An arrow e indicates the rotation direction of the rotation shaft 61. The screw groove 14 is depicted as a four-thread screw in the figure.

  On the other hand, the lip seal member 21 is attached (vulcanized and bonded) to the mounting ring 22 made of a rigid material such as metal that is fixed (fitted) to the inner peripheral surface of the shaft hole 52 of the housing 51. A rubber-like elastic body 23, and by this rubber-like elastic body 23, a seal lip (end-face lip) 24 slidably in close contact with the machine-side end surface 13 a of the flange portion 13 of the slinger 11, and the slinger 11 A non-contact oil recovery lip 25 and a dust lip 26 slidably in close contact with the outer peripheral surface of the cylindrical portion 12 of the slinger 11 are integrally provided. The oil recovery lip 25 is disposed on the outside B of the seal lip 24, and the dust lip 26 is further disposed on the outside B of the oil recovery lip 25.

  In addition to the lips 24, 25, and 26, the static leakage that exhibits the action of suppressing the sealing fluid on the machine inner side A from leaking to the machine outer side B through the screw groove 14 when the rotation of the rotary shaft 61 is stopped. The restraining lip 31 is provided, and the stationary leak suppressing lip 31 is held by the slinger 11 and is in close contact with the lip seal member 21. More specifically, the base end of the lip 31 is a sleeve in the slinger 11. It is joined (vulcanized and bonded) to the outer peripheral surface of the portion 12, and its distal end is in close contact with the distal end of the oil recovery lip 25. Accordingly, the stationary leak suppressing lip 31 is disposed on the machine outside B of the seal lip 24 and on the machine inside A of the oil recovery lip 25, that is, between the seal lip 24 and the oil recovery lip 25.

  Further, when the rotation of the rotation shaft 61 is stopped, the stationary leak suppression lip 31 is in close contact with the lip seal member 21 (the tip of the oil recovery lip 25) as shown in the figure, but the rotation shaft 61 rotates. When the predetermined number of rotations is reached, as shown in FIG. 3, it is elastically deformed by centrifugal force to move away from the lip seal member 21 (the front end portion of the oil recovery lip 25), and the lip seal member 21 (the front end portion of the oil recovery lip 25) An annular gap c is formed between the two.

  In the sealing device 1 having the above-described configuration, the seal lip 24 is slidably brought into close contact with the flange portion 13 of the slinger 11 when the rotary shaft 61 rotates. Since the rotating slinger 11 exerts a fluid swinging action by the flange portion 13 and a fluid pumping action by the thread groove 14, even if there is a fluid passing between the seal lip 24 and the flange portion 13, this is treated on the outer peripheral side (inside A). Therefore, an excellent sealing function is exhibited.

  Further, when the rotation of the rotating shaft 61 stops, the centrifugal force disappears, and the fluid swinging action and the fluid pumping action are temporarily stopped along with this, so that a part of the sealing fluid travels through the screw groove 14 from the machine inner side A. The space 41 between the seal lip 24 and the oil recovery lip 25 flows out into the space 41. The space 41 between the lips is blocked by the stationary leak suppression lip 31 being in close contact with the tip of the oil recovery lip 25. Has been. Therefore, the sealing function by the stationary leak suppressing lip 31 is exhibited, and thereby the sealing fluid is prevented from flowing out from the space 41 between the seal lip 24 and the oil recovery lip 25 to the space 52 between the oil recovery lip 25 and the dust lip 26. Therefore, leakage of the sealing fluid to the outside B can be suppressed.

  In addition, stationary leakage occurs particularly when the vehicle is tilted due to the vehicle stopping on a slope or the like, and the amount of oil (oil level) in the shaft hole 52 of the engine exceeds the lower end 61a of the rotating shaft 61. In the sealing device 1 having the above configuration, the stationary leak suppressing lip 31 is joined to the outer peripheral surface of the sleeve portion 12 of the slinger 11, and the height position thereof excluding the thickness of the sleeve portion 12 of the slinger 11, It is substantially the same as the lower end 61 a of the rotating shaft 61. Therefore, if the oil amount (oil level) does not increase significantly, the sealing fluid does not reach the height position of the stationary leak suppression lip 31. When the oil amount (oil level) is small, the sealing fluid remains stationary. Since it does not reach the height position of the leakage suppression lip 31, stationary leakage can be reliably suppressed, and even if the amount of oil (oil level) increases, the height of the leakage suppression lip can be suppressed to a height position that can cope with this. Since the lip 31 is provided, the occurrence of static leakage can be suppressed by the sealing action exhibited by the static leakage suppressing lip 31. In addition, the fact that the height of the stationary leak suppressing lip 31 is high means that the stationary leak suppressing lip 31 is provided at the radially inner position as much as possible. .

  Further, in the sealing device 1 configured as described above, the stationary leak suppressing lip 31 is elastically deformed by centrifugal force as shown in FIG. 3 when the rotating shaft 61 rotates, and the lip seal member 21 (the tip of the oil recovery lip 25). And an annular gap c is formed between the lip seal member 21 and the tip of the oil recovery lip 25. Therefore, even if the static leakage suppressing lip 31 is provided in addition to the stationary lips 24, 25, 26, it is possible to suppress an increase in the sliding torque of the sealing device 1 as a whole.

Second embodiment ...
In the first embodiment, regarding the disposition of the stationary leak suppressing lip 31, it is joined to the outer peripheral surface of the sleeve portion 12 of the slinger 11 and is in close contact with the tip of the oil recovery lip 25. The invention is not limited to this, and the arrangement is not particularly limited.

  For example, in FIG. 4 shown as the second embodiment, the stationary leak suppressing lip 31 is joined to the outer peripheral surface of the sleeve portion 12 in the slinger 11 and is in close contact with the machine outer end surface 27 of the lip seal member 21. The restraining lip 31 is disposed further on the outboard side B of the dust lip 26.

  As with the slinger 11, the mounting ring 22 of the lip seal member 21 has a flange portion 29 integrally formed at one end of the sleeve portion 28, and a part of the rubber-like elastic body 23 is formed on the machine end face of the flange portion 29. Since it is attached (vulcanized and bonded) as 30, the stationary leak suppressing lip 31 is in close contact with the coating portion 30.

  Further, as in the first embodiment, the stationary leak suppression lip 31 is in close contact with the machine end surface 27 of the lip seal member 21 when the rotation shaft 61 stops rotating, but the rotation shaft 61 rotates. When the predetermined number of rotations is reached, as shown in FIG. 5, it is elastically deformed by a centrifugal force to move away from the machine outer end surface 27 of the lip seal member 21, and an annular gap is formed between the lip seal member 21 and the machine outer end surface 27. c is formed.

  Therefore, also by the sealing device 1 according to the second embodiment, an operational effect equivalent to that of the first embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 Sealing device 11 Slinger 12, 28 Sleeve part 13, 29 Flange part 13a Machine outer side end face 14 Thread groove 21 Lip seal member 22 Mounting ring 23 Rubber-like elastic body 24 Seal lip 25 Oil recovery lip 26 Dustrip 27 Machine outer side end face 30 Coating Part 31 Lip for restraint of static leakage 41, 42 Space between lips 51 Housing 52 Shaft hole 61 Rotating shaft 61a Lower end A Machine inside B Machine outside

Claims (3)

A sealing device for sealing so that a sealing fluid inside the machine does not leak to the outside of the machine between a housing and a rotary shaft inserted through a shaft hole provided in the housing,
It consists of a combination of a slinger attached to the outer periphery of the rotating shaft and a lip seal member attached to the inner periphery of the shaft hole of the housing, and the slinger is a sleeve portion fixed to the outer peripheral surface of the rotating shaft; A flange portion provided at one end of the sleeve portion, a screw groove is provided on an outer end surface of the flange portion, and the lip seal member is fixed to an inner peripheral surface of the shaft hole of the housing. And a rubber-like elastic body attached to the mounting ring, wherein the rubber-like elastic body is provided with a seal lip that comes into contact with the outer end surface of the flange portion of the slinger.
A static leakage suppression lip is provided to suppress leakage of sealing fluid along the screw groove to the outside of the machine when rotation of the rotary shaft is stopped.
The stationary leakage suppressing lip is a rotating lip held by the slinger and in close contact with the lip seal member. The sealing device according to claim 1.
The sealing device according to claim 1, wherein the lip for static leakage suppression is joined to an outer peripheral surface of the sleeve portion of the slinger. The sealing device according to claim 1 or 2,
The stationary leak suppressing lip is in close contact with the lip seal member when the rotation of the rotating shaft is stopped, and is elastically deformed by a centrifugal force when the rotating shaft is rotated to separate from the lip seal member. apparatus.

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