JP3965559B2 - Sealing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device, and more particularly to a sealing device mounted on a device that supplies grease to a sealed space between a housing and a shaft. The device is, for example, a universal joint in a propeller shaft of an automobile drive system.
[0002]
[Prior art]
In the universal joint of the propeller shaft, the grease lip shape of the sealing device mounted and used on this joint varies depending on whether or not the lubricating grease is supplied.
[0003]
That is, first, as shown in FIG. 4 (A), the grease lip 51 has an inward shape in a sealing device that is mounted and used on one of the non-greased type (non-greased type) joints. Since the lip is not turned up (reversed) due to the greasing pressure, the inward lip having a relatively high sealing performance can be used as the grease lip 51.
[0004]
Moreover, as shown in FIG. 4 (B), the grease lip 52 has an outward shape in the sealing device that is mounted and used in the other greasing type (greasing type) joint. This is because the inward lip causes lip turning due to the lubrication pressure and the sealing action cannot be maintained, so the inward lip cannot be used. Use a low outward lip.
[0005]
Therefore, according to the above prior art, when the joint is of a greasing type, an outward lip having a relatively low sealing performance must be used as the grease lip, so that the sealing performance against grease may be insufficient. There is an inconvenience.
[0006]
[Problems to be solved by the invention]
In view of the above points, the present invention does not cause turning of the lip even when an inward lip having a relatively high sealing performance is used as a grease lip when a device such as a joint is a greasing type. It aims at providing the sealing device which can improve sealing performance.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a sealing device according to claim 1 of the present invention is a sealing device attached to a device for supplying grease to a sealed space between a housing and a shaft, and is press-fitted into the inner peripheral side of the housing. And an elastic body made of a rubber-like elastic material vulcanized and bonded to the mounting ring , slidably in close contact with the shaft, and external leakage of the grease An inwardly-shaped grease lip, a flange portion of the mounting ring, and an elastic body made of rubber-like elastic material vulcanized and bonded to the mounting ring, and a housing end surface arranged outside the end surface of the housing a contact portion, and a relief channel of the mounting cylindrical portion a groove-shaped greasing pressure provided on the outer peripheral surface of the ring, the relief is provided between the end surface of the housing the housing end face contact portion The extension path of the road, is molded by an elastic body of the housing end face contacting portion, in close contact with the end surface of the housing, a pressure relief lip outward shape to open the lubrication pressure to open by the lubrication pressure It is characterized by having.
[0008]
A sealing device according to claim 2 of the present invention is a sealing device mounted on a device for supplying grease to a sealed space between a housing and a shaft, and includes a cylindrical portion press-fitted to the inner peripheral side of the housing , and A mounting ring integrally formed with a flange portion, and an elastic body made of a rubber-like elastic material vulcanized and bonded to the mounting ring, are slidably in close contact with the shaft, and foreign matters such as external muddy water and dust are It consists of an outwardly shaped main lip that prevents entry into the sealed space, and an elastic body made of rubber-like elastic material vulcanized and bonded to the mounting ring, and is slidable on the shaft inside the main lip The end face of the housing is made of an inwardly-shaped grease lip that closely contacts and prevents external leakage of the grease, a flange portion of the mounting ring, and an elastic body made of a rubber-like elastic material vulcanized and bonded to the mounting ring Placed outside A housing end face contact portion that is provided between the and the relief channel of the mounting cylindrical portion a groove-shaped greasing pressure provided on the outer peripheral surface of the ring, with the end face of the housing the housing end face contact portion An outwardly shaped pressure that is formed by the extension passage of the escape passage and the elastic body of the housing end surface contact portion, is in close contact with the end surface of the housing, and opens the grease supply pressure to open the grease supply pressure. Formed by a relief lip, a slinger attached to the shaft and forming a labyrinth seal structure with the housing, and an elastic body of the housing end surface contact portion, and slidably in close contact with the inner peripheral surface of the cylindrical portion of the slinger And a cylindrical abutment lip.
[0009]
The sealing device according to claim 3 of the present invention is the sealing device according to claim 1 or 2, wherein the device is specifically a universal joint.
[0010]
When the sealing device according to the first aspect of the present invention having the above configuration is mounted and used in a grease supply type device, a grease supply pressure generated during grease supply is provided on the outer peripheral surface of the cylindrical portion of the mounting ring. The pressure relief lip is reached from the groove-shaped relief passage formed through the extension passage of the relief passage provided between the housing end face and the housing end face contact portion, and the lip is opened to be opened. become. Therefore, since the grease supply pressure is not released to the outside and the grease lip is not turned over, it is possible to use an inwardly shaped lip having a relatively high sealing performance as the grease lip.
[0011]
Further, when the sealing device according to claim 2 of the present invention having the above-described configuration is mounted and used in a grease supply type device, the grease supply pressure generated during the grease supply is also the outer periphery of the cylindrical portion of the mounting ring. The pressure relief lip is reached from the groove-like escape passage provided on the surface through the extension passage of the escape passage provided between the housing end face and the housing end face contact portion, and the lip is opened to open. Will be. Therefore, since the grease supply pressure is not released to the outside and the grease lip is not turned over, it is possible to use an inwardly shaped lip having a relatively high sealing performance as the grease lip. In addition to this, according to the sealing device of claim 2, since the labyrinth seal structure and the cylindrical abutment lip seal structure are provided together with the main lip, it is possible to further improve the sealing performance, particularly the mud water resistance. It becomes.
[0012]
The sealing device of the present invention having the above configuration is preferably used for a universal joint (Claim 3), but can also be used for other devices. The housing includes all parts that can be fitted with the sealing device regardless of its name, and the shaft includes all parts that can slide with the lip regardless of its name.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention are as follows.
[0014]
That is, first, by providing a pressure relief channel (groove) in the mounting ring (seal metal ring part) and further providing a pressure relief lip (rubber lip) at the end surface contact part with the housing (mating housing), only when grease is supplied The structure is designed to release pressure and prevent dust from entering from outside at other times. In addition, the grease lip is changed to an inward shape (grease-free lip shape).
[0015]
The shape of the mounting ring may be any shape (such as a uniform groove or a petal ring), but it must have such a detaching force that the sealing device (seal) does not come out of the housing during use. Since there is a concern about the omission of the seal in the outer peripheral rubber type, it is preferable to use a metal ring for the outer periphery. Since the pressure relief lip does not slide, it does not wear and may have any shape as long as it has a pressing force that opens only when an internal pressure is generated during lubrication. Here, the pressing force of the pressure relief lip is greatly influenced by the seal driving position, so by providing evenly spaced protrusions at the end surface contact with the housing, the displacement of the driving height is suppressed and the pressure releasing lip is pressed. A structure that stabilizes the force.
[0016]
Further, the slinger fitted to the shaft extends to a position that slightly covers the housing to form a labyrinth structure. Further, on the seal side, a lip that is in radial contact with the slinger is provided. This lip has a cylindrical lip type lip shape which is conventionally used for a differential side or the like.
[0017]
According to the above configuration, since the pressure can be released at the time of lubrication, the direction of the grease lip can be directed inward, and the sealing performance (grease retention and grease leak resistance) is improved. Further, by making the slinger and the housing into a labyrinth structure and adding a lip (cylindrical abutment lip) that contacts the slinger, the muddy water resistance and the grease leak resistance can be further improved.
[0018]
【Example】
Next, embodiments of the present invention will be described with reference to the drawings.
[0019]
FIG. 1 shows a cross-section of the main part in a state where the sealing device 1 according to the embodiment of the present invention is mounted on a greasing type universal joint 21. 2 is a view of the sealing device 1 as viewed in the direction of arrow A in FIG.
[0020]
The sealing device 1 is configured as follows.
[0021]
That is, first, a mounting ring 2 made of a rigid material such as a metal fitted to the inner periphery of the housing 22 is provided, and an elastic body 3 made of a rubber-like elastic material is vulcanized and bonded to the mounting ring 2. A plurality of lips are integrally formed on the elastic body 3, and the plurality of lips are provided on the inner peripheral side of the mounting ring 2 and are slidably in close contact with the peripheral surface of the shaft 23, so that external muddy water and dust The main lip 4 and the sub lip 5 having an outward shape for preventing foreign matters such as foreign matter from entering the sealed space 24 between the housing 22 and the shaft 23, and the main lip 4 and the sub lip 5 are provided inside the main lip 4 and the shaft 23. An inwardly-shaped grease lip 6 that is slidably in close contact with the peripheral surface of the housing and prevents the grease supplied to the sealed space 24 from leaking to the outside, and an elastic body of the housing end surface contact portion 7 of the sealing device 1. 3 is formed integrally with the housing end surface 22a. Away freely closely, it is constituted by a pressure relief lip 8 of the outward shape of opening the surplus of greasing pressure and opened by lubrication pressure. A cylindrical portion 2 a that is press-fitted into the inner peripheral side of the housing 22 and a flange portion 2 b that is disposed outside the housing end surface 22 a and forms part of the end surface contact portion 7 are integrally formed on the mounting ring 2. .
[0022]
On the outer peripheral surface of the cylindrical portion 2a of the mounting ring 2, a plurality of groove-like pressure relief passages 9 are provided in a uniform manner along the axial direction in order to release the grease supply pressure in the sealed space 24. . Further, when the sealing device 1 is pressed into the housing 22 from one side in the axial direction, the elastic member 3 of the end surface contact portion 7 is in contact with the housing end surface 22a to specify the press-fitting position (depth), and In order to secure the extension path 10 of the pressure relief flow path 9 between the housing end surface 22a and the end surface contact portion 7, the projections 11 are arranged in a plurality of uniform shapes (preferably 4 to 6 or more are preferable). It may be provided. The extension passage 10 is disposed between the pressure relief passage 9 and the pressure relief lip 8 so as to communicate the both 8 and 9. By providing the extension passage 10, the pressure in the sealed space 24 is supplied. The pressure relief lip 8 is reached while being increased by the oil pressure, and when the pressure reaches a certain level, the lip 8 is opened to release the internal pressure to the outside. By doing so, it can prevent that lubrication becomes difficult by the increase in internal pressure. When the protrusion 11 is used for positioning, the height of the protrusion 11 can also be used for adjusting the valve opening pressure of the lip 8.
[0023]
Further, the sealing device 1 is provided with an annular slinger 12 that is fitted to the outer periphery of the shaft 23, and a cylindrical abutment lip 13 that is slidably in close contact with the slinger 12.
[0024]
Among these, the former slinger 12 has a tip 12b of the outer peripheral cylindrical portion 12a positioned on the outer peripheral side of the housing 22, and a minute amount between the inner peripheral surface of the front end 12b of the outer peripheral cylindrical portion 12a and the outer peripheral surface of the housing 22. The labyrinth seal structure 15 is formed by forming the gap 14. As shown in FIG. 3, an annular concave step 25 is provided on the outer peripheral edge of the housing 22, and the tip 12 b of the outer peripheral cylindrical portion 12 a is connected to the concave step 25. In this case, the gap 14 is formed in an L-shaped cross section having a radial portion and an axial portion.
[0025]
The latter cylindrical abutting lip 13 is integrally formed as a relatively large lip that expands in a trumpet shape on the back side of the elastic body 3 of the end surface contact portion 7, and is formed with respect to the inner peripheral surface of the outer peripheral cylindrical portion 12 a of the slinger 12. And slidably close.
[0026]
The sealing device 1 configured as described above first prevents foreign matter such as external muddy water and dust from entering the sealed space 24 at the main lip 4 and the sub lip 5, and further, the labyrinth seal structure 15 and the cylinder abutment are disposed on the front side thereof. Since the lip 13 is provided in series, foreign substances can be sealed more effectively.
[0027]
Further, the grease lip 6 seals the leakage of the grease in the sealed space 24 to the outside. Since the grease lip 6 is a lip having an inward shape with a relatively high sealing performance, the grease is effectively used. Can be sealed. In spite of the universal joint 21 being a greasing type, the inwardly shaped lip can be used as the grease lip 6 as described above, because the surplus of the greasing pressure generated at the time of grease greasing is released. This is because the pressure relief lip 8 is released via the flow path 9 and the extension path 10, and thus the grease lip 6 is not turned up.
[0028]
The pressure relief lip 8 is closed except when the pressure is released, so that no external foreign matter enters from the lip seal portion.
[0029]
【The invention's effect】
The present invention has the following effects.
[0030]
That is, in the sealing device according to the first aspect of the present invention having the above-described configuration, when the sealing device is mounted and used in a grease lubrication type device, the grease supply pressure generated during grease lubrication is reduced. A pressure relief lip is reached from a groove-like escape passage provided on the outer peripheral surface of the cylindrical portion via an extension passage of the escape passage provided between the housing end surface and the housing end surface contact portion. Since the valve is opened for opening, it is possible to prevent the grease lip from being turned up by the grease supply pressure. Therefore, along with this, even if the apparatus is a greasing type, it is possible to use an inward lip having a relatively high sealing performance as a grease lip, so that the sealing performance can be improved.
[0031]
Further, in the sealing device according to claim 2 of the present invention having the above-described configuration, when the sealing device is mounted and used in a grease supply type device, the grease supply pressure generated during the grease supply is also reduced. The pressure relief lip is reached from the groove-like escape passage provided on the outer peripheral surface of the cylindrical portion of the cylindrical portion through the extension passage of the escape passage provided between the end face of the housing and the housing end face contact portion. Therefore, the grease lip can be prevented from turning up due to the grease supply pressure. Therefore, along with this, even if the apparatus is a greasing type, it is possible to use an inward lip having a relatively high sealing performance as a grease lip, so that the sealing performance can be improved. In addition, since the labyrinth seal structure and the cylindrical abutment lip seal structure are provided together with the main lip in the sealing device of claim 2, the sealing performance, in particular, the mud water resistance can be further improved. .
[0032]
In the sealing device according to the third aspect of the present invention having the above-described configuration, the above-described effects can be obtained using the universal joint as a product, and the quality of the universal joint can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a sealing device according to an embodiment of the present invention. FIG. 2 is a view taken along the direction A in FIG. Cross-sectional view of essential parts [FIG. 4] (A) and (B) are cross-sectional views of essential parts of the sealing device according to the conventional example [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sealing device 2 Mounting ring 2a Tubular part 2b Flange part 3 Elastic body 4 Main lip 5 Sub lip 6 Grease lip 7 Housing end surface contact part 8 Pressure relief lip 9 Pressure relief channel 10 Extension path 11 Projection 12 Slinger 12a Outer cylinder part (Cylindrical part)
12b Tip 13 Cylindrical abutment lip 14 Gap 15 Labyrinth seal structure 21 Universal joint (device)
22 Housing 23 Shaft 24 Sealed space 25 Concave step

Claims (3)

A sealing device (1) mounted on a device (21) for supplying grease to a sealed space (24) between a housing (22) and a shaft (23),
A mounting ring (2) integrally formed with a cylindrical part (2a) and a flange part (2b) which are press-fitted into the inner peripheral side of the housing (22);
An inward shape formed of an elastic body (3) made of a rubber-like elastic material vulcanized and bonded to the mounting ring (2), and slidably in close contact with the shaft (23) to prevent external leakage of the grease Grease lip (6),
The flange portion (2b) of the mounting ring (2) and an elastic body (3) made of a rubber-like elastic material vulcanized and bonded to the mounting ring (2), the end surface (22a) of the housing (22) A housing end surface contact portion (7) disposed on the outside;
A groove-shaped grease supply pressure relief passage (9) provided on the outer peripheral surface of the cylindrical portion (2a) of the mounting ring (2) ;
An extension path (10) of the escape passage (9) provided between the end face (22a) of the housing (22) and the housing end face contact portion (7);
An outward direction which is formed by the elastic body (3) of the housing end surface contact portion (7), is in close contact with the end surface (22a) of the housing (22), and is opened by the greasing pressure to release the greasing pressure. Sealing device characterized by having a pressure relief lip (8) in the shape. A sealing device (1) mounted on a device (21) for supplying grease to a sealed space (24) between a housing (22) and a shaft (23),
A mounting ring (2) integrally formed with a cylindrical part (2a) and a flange part (2b) which are press-fitted into the inner peripheral side of the housing (22);
It consists of an elastic body (3) made of rubber-like elastic material that is vulcanized and bonded to the mounting ring (2), and is slidably in close contact with the shaft (23), so that foreign matters such as external muddy water and dust are sealed. An outwardly shaped main lip (4) that prevents entry into the space (24);
The elastic body (3) made of a rubber-like elastic material bonded to the mounting ring (2) by vulcanization , is slidably in close contact with the shaft (23) inside the main lip (4), and the grease An inwardly-shaped grease lip (6) that prevents external leakage of
The flange portion (2b) of the mounting ring (2) and an elastic body (3) made of a rubber-like elastic material vulcanized and bonded to the mounting ring (2), the end surface (22a) of the housing (22) A housing end surface contact portion (7) disposed on the outside;
A groove-shaped grease supply pressure relief passage (9) provided on the outer peripheral surface of the cylindrical portion (2a) of the mounting ring (2) ;
An extension path (10) of the escape passage (9) provided between the end face (22a) of the housing (22) and the housing end face contact portion (7);
An outward direction which is formed by the elastic body (3) of the housing end surface contact portion (7), is in close contact with the end surface (22a) of the housing (22), and is opened by the greasing pressure to release the greasing pressure. Shaped pressure relief lip (8);
A slinger (12) attached to the shaft (23) and forming a labyrinth seal structure (15) with the housing (22);
A cylindrical abutment lip (13) formed by an elastic body (3) of the housing end surface contact portion (7) and slidably in close contact with the inner peripheral surface of the cylindrical portion (12a) of the slinger (12); Sealing device characterized. The sealing device according to claim 1 or 2,
A sealing device, characterized in that the device (21) is specifically a universal joint.

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