JP2005147356A - Sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize lowering of torque of a lip seal 6 constituting a main sealing part 2 while enough keeping the sealing function at the time of high speed rotation. <P>SOLUTION: This sealing device 1 is mounted between a housing 3 and a rotating shaft 5 passed through the housing 3 to perform sealing action. The sealing device has the main sealing part 2 including: a metal ring 4 fixed to the housing 3 side; and a lip seal 6 fixed to the rotating shaft 5 side to rotate with the rotating shaft 5 and having low torque specification so that it is brought into sliding contact with the metal ring 4 during low-speed rotation and separated from the metal ring 4 by centrifugal force during high speed rotation. In addition to the above, the sealing device has an auxiliary sealing part 14 acting as the complementary operation for the sealing operation of the main sealing part 2 during high-speed rotation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sealing device according to a sealing technique, and more particularly to a sealing device that realizes a reduction in torque of a lip seal that constitutes a main seal portion. The sealing device of the present invention is used, for example, in the field of automobiles, or used in other general industrial machines.

  As shown in FIG. 4, in a bearing mechanism 52 of a drive shaft 51 in a vehicle such as an automobile, for example, a housing (bearing housing) 54 and a rotary shaft (drive shaft) are sealed in order to seal a lubricating oil (not shown) that lubricates the bearing 53. ) 51 is mounted between the sealing devices 55 (see Patent Document 1).

  However, in this prior art, a lip seal (oil seal) 56 that constitutes a specific component of the sealing device 55 is fixed to the housing 54 side and is always slidably in close contact with the rotating shaft 51. The lowering of the torque of the lip seal 56 for enhancing the durability of the lip seal 56 is dealt with exclusively by a method of reducing the tension (lowering the surface pressure) by reducing the cross section of the lip seal 56.

  Therefore, according to this prior art, there is a disadvantage that the followability of the lip seal 56 at a low temperature is lowered or the sealing function becomes unstable at a high speed rotation, and the reduction of the surface pressure when the cross section is reduced ( Therefore, a fundamental review of the sealing mechanism is required.

  In addition, in order to examine a seal with a new mechanism, there are many restrictions including assemblability and axial movement, and these conditions need to be considered in the seal design.

Japanese Utility Model Publication No. 62-62069 (FIG. 1)

  In view of the above, the present invention provides a sealing device capable of realizing a reduction in torque of a lip seal constituting a main seal portion while sufficiently maintaining a sealing function, particularly a sealing function during high-speed rotation. For the purpose.

  To achieve the above object, a sealing device according to claim 1 of the present invention is a metal ring fixed to the housing side in a sealing device which is mounted between a housing and a rotating shaft inserted through the housing and performs a sealing action. And a lip seal that is fixed to the rotating shaft side and rotates with the rotating shaft, and is slidably in close contact with the metal ring during low-speed rotation and is separated from the metal ring by centrifugal force during high-speed rotation. And a sub seal portion provided between the metal ring and the rotating shaft and supplementing the seal operation by the main seal portion during high-speed rotation. .

  The sealing device according to claim 2 of the present invention is the sealing device according to claim 1, wherein the sub seal portion is set between the metal ring and the rotating shaft or a part fixed to the rotating shaft. It is a labyrinth structure of contact.

  According to a third aspect of the present invention, there is provided the sealing device according to the first aspect, wherein the sub seal portion is always slidable on the rotating shaft or a part fixed to the rotating shaft supported by the metal ring. It is characterized by being a lip seal closely in contact with.

  In the sealing device according to claim 1 of the present invention having the above-described configuration, the lip seal is fixed not to the housing side but to the rotating shaft side and rotates together with the rotating shaft. It is possible to reduce the torque of the lip seal using force. In other words, the lip seal is in contact with the metal ring that is the counterpart sliding part when the shaft rotates at a low speed, but since the centrifugal force acts even though it is relatively small, the contact surface pressure is reduced by this centrifugal force, Low torque is realized. Further, when the shaft rotates at a high speed, a relatively large centrifugal force acts, so that the centrifugal force separates the metal ring, and a further reduction in torque is realized. However, if the lip seal is kept away from the metal ring, the sealing function may be hindered. Therefore, in the present invention, the secondary seal portion that complements the seal operation by the lip seal (main seal portion) at the time of high speed rotation is also included. I decided to provide it.

  Specific examples of the sub-seal portion include a non-contact labyrinth structure set between a metal ring and a rotating shaft or a part fixed to the rotating shaft (Claim 2), and rotation supported by the metal ring. A lip seal that is always slidably in close contact with a shaft or a component fixed to the rotary shaft is preferable.

  The present invention has the following effects.

  That is, in the sealing device according to claims 1 to 3 of the present invention having the above-described configuration, the lip seal constituting the main seal portion is fixed to the rotating shaft side instead of the housing side and rotates together with the rotating shaft. At low speed, it is slidably in close contact with the metal ring, and at high speed, it has a low torque specification that separates from the metal ring due to centrifugal force. It is possible to reduce the torque of the seal. Therefore, it is possible to prevent the lip seal from sliding and wearing at an early stage and improve its durability. In addition, a secondary seal part that complements the seal operation of the main seal part during high-speed rotation is also provided, so that the lip seal can be separated from the metal ring so that a sufficient sealing function can be achieved even during high-speed rotation. can do. Therefore, as described above, it is possible to provide a sealing device capable of reducing the torque of the lip seal while maintaining the sealing function during high-speed rotation as intended.

  The present invention includes the following embodiments.

1) As a basic content, low torque is achieved with a seal rotation type. The seal rotation mechanism ensures the sealing performance with the rubber lip at low rotation, and the lip opens by centrifugal force at high rotation, resulting in a low torque specification. Cover with labyrinth structure or secondary lip.
2) A seal rotation system is built by incorporating a seal on the shaft side and a metal ring as a mating sliding part on the housing side, and lowering the seal torque by lowering the surface pressure due to centrifugal force (lifting the lip). To do. Furthermore, by using a grooved slinger or a grooved shaft on the shaft side, the amount of oil reaching the seal during rotation is controlled, and both high sealing performance and low torque are achieved at high rotation.

3) As an incidental content, by fitting a seal on the shaft side and fitting a metal ring on the housing side, the direction of the lip is made to be a direction in which lip turning is unlikely to occur, and assembling is improved (details will be described later).
4) As an incidental content, a muddy water resistance and a seal guard property are provided by providing a deflector on the shaft side. Further, by providing a labyrinth structure between the deflector and the metal ring, the muddy water resistance is further improved (details will be described later).
5) As an incidental content, a straight portion larger than the sliding portion is provided on the metal ring fitted on the housing side so as to correspond to the axial movement of the shaft (details will be described later).

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

First embodiment ...
FIG. 1 is a half-sectional view showing a mounting state of the sealing device 1 according to the first embodiment of the present invention. The sealing device 1 according to the embodiment seals the lubricating oil inside the mechanism A for lubricating the bearing so that it does not leak to the outside B of the mechanism in the bearing mechanism of the drive shaft in the vehicle such as an automobile. This seals foreign matter such as muddy water and dust so as not to enter the mechanism interior A, and is configured as follows.

  That is, first, the sealing device 1 has a main seal portion 2 for sealing the lubricating oil inside the mechanism A, and the main seal portion 2 is connected to the metal ring 4 fitted on the housing 3 side. The combination with the lip seal 6 fitted on the rotating shaft 5 side.

  The metal ring 4 includes an outer peripheral cylindrical portion 4a fitted on the inner peripheral side of the housing 3 and one axial end portion thereof (the right end portion in the figure, the bearing inner A side, and hence the "axial inner end portion"). The annular flat portion 4b integrally formed radially inward from the inner peripheral end portion and the other end side in the axial direction (the left end side in the figure, the bearing outer B side). The inner peripheral cylindrical portion 4c integrally formed toward the outer side) and the other axial end portion of the outer peripheral cylindrical portion 4a (the left end portion in the drawing, the bearing outer B side). A flat flange portion 4d that is integrally formed radially outward from the outer peripheral end and an annular taper portion 4e that is integrally formed obliquely outward from its outer peripheral end. It is manufactured by sheet metal press molding or the like.

  The lip seal 6 has a metal mounting ring 7 fitted on the outer peripheral side of the rotating shaft 5, and a lip seal body 8 made of rubber-like elastic material is attached to the tip of the mounting ring 7. Yes. The mounting ring 7 includes a cylindrical portion 7a fitted on the outer peripheral side of the large-diameter portion 5a of the rotating shaft 5, and a planar flange portion integrally formed from the axial inner end portion toward the radial inner side. 7b and the lip seal body 8 is vulcanized and bonded to the inner peripheral end of the flange portion 7b.

  The lip seal body 8 has a main seal lip 9 provided radially inward from the inner peripheral end of the flange portion 7b and obliquely outward in the axial direction, and in the same direction inward in the axial direction. The auxiliary seal lip 10 is integrally provided, and both the seal lips 9, 10 are slidably in close contact with the outer peripheral surface of the inner peripheral cylindrical portion 4 c in the metal ring 4 to seal the lubricating oil. It is configured. A garter spring 11 for adjusting the contact surface pressure is attached to the main seal lip 9. The main seal lip 9 is slidably in close contact with the outer peripheral surface of the inner peripheral cylindrical portion 4c of the metal ring 4 when the shaft 5 is rotated at a low speed. The metal ring 4 is configured to elastically expand outward in the radial direction by the generated centrifugal force and away from the outer peripheral surface of the inner peripheral cylindrical portion 4 c in the metal ring 4. The contact surface pressure with respect to the cylindrical portion 4c is set to a relatively low low torque specification.

  On the outer peripheral side of the cylindrical portion 7a or the flange portion 7b in the mounting ring 7, a dust strip 12 made of a rubber-like elastic material is provided diagonally outward in the radial direction and outward in the axial direction. The dust lip 12 is always slidably in close contact with the inner peripheral surface of the outer peripheral cylindrical portion 4a in the metal ring 4, and seals the foreign matter outside the mechanism B so as not to enter the mechanism inside A. The dust lip 12 is formed integrally with the lip seal body 8. Further, the outer peripheral surface of the cylindrical portion 7a in the mounting ring 7 is covered with a film portion 13 made of a rubber-like elastic material that is integrated with the dust strip 12 to protect the mounting ring 7 from external foreign matters, particularly muddy water. ing.

  Further, the sealing device 1 has a sub seal portion 14 for supplementing the seal operation by the main seal portion 2 during high-speed rotation, and the sub seal portion 14 rotates with the metal ring 4. It is comprised by the combination with the slinger 16 fixed to the axis | shaft 5 side. That is, a slinger 16 having a cylindrical shape is fitted to the outer peripheral side of the small diameter portion 5 b of the rotating shaft 5 on the inner peripheral side of the metal ring 4, and the outer peripheral surface of the slinger 16 and the inner peripheral cylindrical portion of the metal ring 4. Between the inner peripheral surface of 4c, a gap portion 17 formed of a minute radial gap is provided. A spiral groove 18 is provided on the outer peripheral surface of the slinger 16 to push the lubricating oil back to the mechanism interior A side by the pumping action when the shaft 5 is rotated. A contact labyrinth structure (labyrinth seal structure) 15 is configured.

  The sealing device 1 also includes a deflector 19 for protecting the sealing device 1 from muddy water, stepping stones, and the like. The deflector 19 is fitted to the outer peripheral side of the rotary shaft 5 together with the lip seal 6. ing. The deflector 19 includes a cylindrical portion 19a fitted on the outer peripheral side of the cylindrical portion 7a of the mounting ring 7 in the lip seal 6 on the outer peripheral side of the large-diameter portion 5a of the rotary shaft 5, and an inner end in the axial direction thereof. It integrally has a flange portion 19b formed integrally from the side toward the radially outward side, and is manufactured by sheet metal press molding or the like. Further, a labyrinth structure (labyrinth seal structure) 20 having a minute gap is also provided between the outer peripheral end portion of the flange portion 19a of the deflector 19 and the tapered portion 4e of the metal ring 4, and this labyrinth structure is also provided here. 20 makes it difficult for an external foreign object to enter.

  The sealing device 1 having the above-described structure seals the drive shaft bearing mechanism in a vehicle such as an automobile as described above so that the lubricating oil inside the mechanism A for lubricating the bearing does not leak to the mechanism outside B, and This seals the foreign matter such as the muddy water and dust of B so as not to enter the mechanism interior A, and is characterized by the following effects.

  That is, first, in the sealing device 1 configured as described above, the lip seal 6 constituting the main seal portion 2 for sealing the lubricating oil is fixed not to the housing 3 side but to the rotating shaft 5 side so as to rotate together with the rotating shaft 5. And is slidably in close contact with the outer peripheral surface of the inner peripheral cylindrical portion 4c in the metal ring 4 during low-speed rotation, and is separated from the outer peripheral surface of the inner peripheral cylindrical portion 4c in the metal ring 4 by centrifugal force during high-speed rotation. Because of the construction, the lip seal 6 has a reduced torque. That is, when the shaft 5 rotates at a low speed, the lip seal 6 is in contact with the outer peripheral surface of the inner peripheral cylindrical portion 4c in the metal ring 4 which is the counterpart sliding part, but centrifugal force acts although it is relatively small. Moreover, the contact surface pressure is reduced by this centrifugal force, and a reduction in torque is realized. The lip seal 6 slides on the outer peripheral surface of the inner peripheral cylindrical portion 4c in the metal ring 4, but does not generate a large torque because of the low speed rotation. Further, when the shaft 5 rotates at a high speed, a relatively large centrifugal force acts, so that the centrifugal force separates from the outer peripheral surface of the inner peripheral cylindrical portion 4c in the metal ring 4 and a further reduction in torque is realized. Therefore, it is possible to prevent the occurrence of a situation in which the lip seal 6 slides under a high torque condition and slides and wears at an early stage, thereby improving the durability of the lip seal 6. it can. Further, since the auxiliary seal portion 14 made of the labyrinth structure 15 for supplementing the seal operation by the main seal portion 2 at the time of high-speed rotation is also provided, the lip seal 6 forming the main seal portion 2 is made of a metal ring. A sufficient sealing function can be exhibited even during high-speed rotation away from 4. Therefore, according to the intended purpose, it is possible to provide the sealing device 1 capable of realizing the reduction in torque of the lip seal 6 while maintaining the sealing function at the time of high-speed rotation and improving the durability thereof. it can.

  In addition, in the sealing device 1 having the above-described configuration, a dust lip 12 that is slidably in close contact with the inner peripheral surface of the outer peripheral cylindrical portion 4a in the metal ring 4 is provided, and further, the deflector 19 and the metal ring 4 are provided on the outer side. Since the labyrinth structure 20 made of the combination of the above is provided, it is possible to effectively prevent the entry of external foreign matters by these.

  In addition, in the sealing device 1 configured as described above, when the lip seal 6 is assembled into the metal ring 4 as indicated by an arrow in the figure, the direction of the lip seal 6 (the direction of the axial direction) is such that lip turning is unlikely to occur. It is said that. The same applies to the dust strip 12. Therefore, from these things, the sealing device 1 excellent in the assembly workability can be provided.

  Furthermore, in the sealing device 1 having the above-described configuration, the axial length of the inner peripheral cylindrical portion 4c in the metal ring 4 is sufficiently larger than the axial length of the lip seal body 8 in the lip seal 6 as shown in the figure. It is greatly formed. Therefore, it is possible to provide the sealing device 1 that can maintain the sealing function even when a situation occurs in which the rotating shaft 5 moves in the axial direction with respect to the housing 3 during some sealing operation of the sealing device 1.

Second embodiment ...
FIG. 2 is a half-cut sectional view showing a mounting state of the sealing device 1 according to the second embodiment of the present invention. The sealing device 1 according to this embodiment seals a drive shaft bearing mechanism in a vehicle such as an automobile so that the lubricating oil inside the mechanism A that lubricates the bearing does not leak to the outside B of the mechanism. The foreign matter such as muddy water and dust outside the mechanism B is sealed so as not to enter the mechanism inside A, and is configured as follows.

  That is, first, the sealing device 1 has a main seal portion 2 for sealing the lubricating oil inside the mechanism A, and the main seal portion 2 is connected to the metal ring 4 fitted on the housing 3 side. The combination with the lip seal 6 fitted on the rotating shaft 5 side.

  The metal ring 4 has a cylindrical portion 4a fitted on the inner peripheral side of the housing 3 via an outer peripheral seal portion 21 made of rubber-like elastic material attached to the surface thereof, and a radial direction from the axial inner end thereof. It has a flat flange portion 4f that is integrally molded inward, and is manufactured by sheet metal press molding or the like.

  The lip seal 6 has a metal mounting ring 7 fitted on the outer peripheral side of the rotating shaft 5, and a lip seal body 8 made of rubber-like elastic material is attached to the tip of the mounting ring 7. Yes. The mounting ring 7 integrally includes a cylindrical portion 7a fitted on the outer peripheral side of the rotary shaft 5 and a planar flange portion 7b integrally formed from the inner end in the axial direction outward in the radial direction. The lip seal body 8 is vulcanized and bonded to the outer peripheral end of the flange portion 7b.

  The lip seal body 8 has a seal lip 9 that is provided radially outward from the outer peripheral end of the flange portion 7b and obliquely outward in the axial direction. The seal lip 9 is a metal ring. 4 is configured to be slidably in close contact with the end face (inner end face) of the flange portion 4f in order to seal the lubricating oil. The seal lip 9 is slidably in close contact with the end face of the flange portion 4f of the metal ring 4 when the shaft 5 rotates at a low speed. However, when the shaft 5 rotates at a high speed, a large centrifugal force is generated. The metal ring 4 is configured to elastically expand outwardly by force and away from the end face of the flange portion 4f in the metal ring 4, so that the contact surface pressure of the metal ring 4 with respect to the flange portion 4f is relatively low. It is set to a small low torque specification.

  Further, as shown in FIG. 3, the metal ring side end surface of the seal lip 9 is lubricated by a pumping action when the seal lip 9 is separated from the end surface of the flange portion 4f of the metal ring 4 when the shaft 5 rotates at high speed. A spiral rib 27 is provided to push oil back to the mechanism interior A side, and the rib 27 is configured to complement the seal operation during high-speed rotation. The rib 27 is not provided in the vicinity of the tip of the seal lip 9 so as not to prevent the seal lip 9 from contacting the metal ring 4 when the shaft 5 is stopped and rotated at a low speed. It is provided on the base side of the seal lip 9. In addition, as shown in FIG. 3 (A), a plurality of linear ribs 27 are arranged in a uniform arrangement, as shown in FIG. 3 (B), (C), or (D). The shape may be an arc shape or a crescent shape, and is not particularly limited.

  Further, an inner peripheral seal portion 22 made of a rubber-like elastic material that is always in contact with the peripheral surface of the rotating shaft 5 is provided on the end surface (inner end surface) of the flange portion 7 b in the mounting ring 7. The inner peripheral seal portion 22 forms a part of the lip seal body 8 and is formed integrally with the seal lip 9.

  Further, the sealing device 1 has a sub seal part 14 for supplementing the seal operation by the main seal part 2 during high-speed rotation, and the sub seal part 14 is supported by the metal ring 4. The lip seal 23 is slidably in close contact with the mounting ring 7 at all times. The lip seal 23 has a seal lip 24 which is vulcanized and bonded to the inner peripheral end portion of the flange portion 4f of the metal ring 4. The seal lip 24 has lip ends 25 and 26 having a two-stage structure in the axial direction. The two-stage lip ends 25 and 26 are in close contact with the outer peripheral surface of the cylindrical portion 7a of the mounting ring 7 so as to be always slidable.

  As described above, the sealing device 1 having the above-described structure seals the lubricating oil inside the mechanism A for lubricating the bearing so as not to leak to the outside B of the mechanism in the bearing mechanism of the drive shaft in the vehicle such as an automobile. In particular, a foreign matter such as muddy water or dust outside the mechanism B is sealed so as not to enter the mechanism inside A, and the above-described configuration has the following effects.

  That is, in the sealing device 1 configured as described above, the lip seal 6 constituting the main seal portion 2 for sealing the lubricating oil is fixed not to the housing 3 side but to the rotating shaft 5 side and rotates together with the rotating shaft 5. This lip seal is arranged and configured to elastically expand outwardly and obliquely outward by centrifugal force when the shaft 5 rotates at a high speed and away from the end face of the flange portion 4f of the metal ring 4. The torque reduction of 6 is realized. When the shaft 5 rotates at a low speed, the lip seal 6 slides on the end face of the flange portion 4f in the metal ring 4, but a large torque is not generated because of the low-speed rotation. Therefore, it is possible to prevent the occurrence of a situation in which the lip seal 6 slides under a high torque condition and slides and wears at an early stage, thereby improving the durability of the lip seal 6. it can. Further, since the auxiliary seal portion 14 composed of the lip seal 23 for supplementing the seal operation by the main seal portion 2 at the time of high-speed rotation is also provided, the lip seal 6 forming the main seal portion 2 is made of a metal ring. A sufficient sealing function can be exhibited even during high-speed rotation away from 4. Therefore, according to the intended purpose, it is possible to provide the sealing device 1 capable of realizing the reduction in torque of the lip seal 6 while maintaining the sealing function at the time of high-speed rotation and improving the durability thereof. it can. Note that the lip seal 23 of the sub seal portion 14 has a secondary sealing action, so that the contact surface pressure against the mounting ring 7 can be set relatively small. It is possible to ensure the durability.

  In addition, since the sealing device 1 having the above-described configuration is provided with a spiral rib 27 on the end face of the metal ring of the seal lip 9, the rib 27 also complements the sealing operation of the main seal portion 2 during high-speed rotation. can do.

  Each of the sealing devices 1 according to the first or second embodiment can be modified in the technical scope of the present invention. For example, in the first embodiment, the sub seal portion 14 is configured by a combination of the metal ring 4 and the slinger 16, but may be a combination of the metal ring 4 and the rotating shaft 5. In this case, the groove portion 18 is formed on the outer peripheral surface of the rotating shaft 5. Similarly, the lip seal 23 in the second embodiment may be slidably brought into close contact with the outer peripheral surface of the rotary shaft 5.

Sectional drawing which shows the mounting state of the sealing device which concerns on 1st Example of this invention. Sectional drawing which shows the mounting state of the sealing device which concerns on 2nd Example of this invention. (A) (B) (C) and (D) are explanatory views of spiral ribs, respectively. Sectional drawing which shows the mounting state of the sealing device which concerns on a prior art example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sealing device 2 Main seal part 3 Housing 4 Metal ring 4a Outer peripheral cylinder part 4b Plane part 4c Inner peripheral cylinder part 4d, 4f, 7b Flange part 4e Taper part 5 Rotating shaft 5a Large diameter part 5b Small diameter part 6, 23 Lip seal 7 Mounting ring 7a Cylindrical part 8 Lip seal body 9 Main seal lip 10 Sub seal lip 11 Garter spring 12 Dustrip 13 Film part 14 Sub seal part 15, 20 Labyrinth structure 16 Slinger 17 Gap part 18 Groove part 19 Deflector 21 Outer peripheral seal part 22 Inner seal 25, 26 Lip end 27 Rib A Bearing mechanism inside B Bearing mechanism outside

Claims (3)

In the sealing device (1) mounted between the housing (3) and the rotating shaft (5) inserted through the housing (3) and performing a sealing action,
A metal ring (4) fixed to the housing (3) side, and fixed to the rotating shaft (5) side, rotates with the rotating shaft (5), and slides on the metal ring (4) during low-speed rotation. A main seal portion (2) provided with a lip seal (6) which is in close contact freely and has a low torque specification which is separated from the metal ring (4) by centrifugal force during high-speed rotation;
It has a sub seal part (14) provided between the metal ring (4) and the rotating shaft (5), and performing an action of complementing the seal operation by the main seal part (2) during high speed rotation. Sealing device. The sealing device of claim 1.
The sub seal portion (14) is a non-contact labyrinth structure (15) set between the metal ring (4) and the rotating shaft (5) or the component (16) fixed to the rotating shaft (5). A sealing device characterized by being. The sealing device of claim 1.
The sub seal part (14) is supported by the metal ring (4) and is always slidably in close contact with the rotating shaft (5) or the part (7) fixed to the rotating shaft (5). The sealing device characterized by being.

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