CN212251132U - Sealing device - Google Patents
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- CN212251132U CN212251132U CN202020470609.6U CN202020470609U CN212251132U CN 212251132 U CN212251132 U CN 212251132U CN 202020470609 U CN202020470609 U CN 202020470609U CN 212251132 U CN212251132 U CN 212251132U
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- cylindrical portion
- seal lip
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Abstract
The utility model provides a sealing device, the wearing and tearing of its lip are little, and the torque of applying to the rotating body is little. The sealing device seals a gap between the housing and the rotating body disposed in the hole of the housing, and separates an internal space of the housing from an atmosphere side. The sealing device has: an attachment cylindrical portion attached to the housing; a seal cylindrical portion disposed radially inward of the attachment cylindrical portion; a connection annular portion connecting the atmosphere side of the mounting cylindrical portion and the seal cylindrical portion; a primary seal lip; and a secondary seal lip. These seal lips project from the inner peripheral surface of the seal cylindrical portion. The main seal lip is always in slidable contact with the outer peripheral surface of the rotating body, and the sub seal lip is in slidable contact with the outer peripheral surface of the rotating body when pressure is applied from the outside to the seal cylindrical portion. The minimum thickness of the end portion on the atmosphere side of the seal cylindrical portion is 1/2 or less of the length from the connecting annular portion to the lip edge of the main seal lip in the axial direction of the seal device.
Description
Technical Field
The utility model relates to a sealing device.
Background
The links (e.g., arms) of the articulated robot may be rotated directly by the motor or may be rotated from the motor via a gear reducer. An oil seal used for a gear reducer for driving a link of an articulated robot is known (patent document 1). The oil seal seals a gap between a shaft that rotates and is disposed on the housing and the housing.
Documents of the prior art
Patent document
SUMMERY OF THE UTILITY MODEL
Problem to be solved by the utility model
For such an oil seal, it is preferable that the lip portion is less worn and the torque applied to the rotating body is small.
Therefore, the present invention provides a sealing device in which the wear of the lip portion is small and the torque applied to the rotating body is small.
Means for solving the problems
A certain aspect of the present invention relates to a sealing device for sealing a gap between a housing and a rotating body, and will the inner space of the housing is separated from the atmosphere side, the rotating body is disposed in a hole of the housing, the sealing device has: an attachment cylindrical portion attached to the housing; a seal cylindrical portion disposed radially inward of the attachment cylindrical portion; a connecting annular portion connecting an end portion of the attachment cylindrical portion on an atmosphere side and an end portion of the seal cylindrical portion on the atmosphere side in a radial direction; a main seal lip projecting from an inner peripheral surface of the seal cylindrical portion and slidably contacting an outer peripheral surface of the rotating body; and a sub seal lip protruding from an inner peripheral surface of the seal cylindrical portion and disposed on an atmospheric side of the main seal lip, wherein an inner diameter of the sub seal lip is larger than an inner diameter of the main seal lip. The secondary seal lip does not contact the outer peripheral surface of the rotating body when no pressure is applied thereto, and slidably contacts the outer peripheral surface of the rotating body when pressure is applied from the outside to the seal cylindrical portion. The seal cylinder portion, the primary seal lip, and the secondary seal lip are formed only of an elastic material. The mounting cylindrical portion and the coupling annular portion are formed of the elastic material and a rigid material. The minimum thickness of the end portion on the atmosphere side of the seal cylindrical portion is 1/2 or less of the length from the connecting annular portion to the lip edge of the main seal lip in the axial direction of the sealing device.
In this aspect, the secondary seal lip does not contact the outer peripheral surface of the rotating body when no pressure is applied, but slidably contacts the outer peripheral surface of the rotating body when pressure is applied to the seal cylindrical portion from the outside, and an increase in the tightening force applied to the rotating body by the primary seal lip that is always slidably in contact with the outer peripheral surface of the rotating body is suppressed. Therefore, wear of the main seal lip can be reduced, and an increase in torque applied to the rotating body can be suppressed. The coupling annular portion is formed of an elastic material and a rigid material and has high rigidity, but the seal cylindrical portion supported by the coupling annular portion is formed of only an elastic material and has low rigidity, and the thickness of the end portion on the atmosphere side of the seal cylindrical portion is small. Therefore, when pressure is applied to the seal cylindrical portion from the outside, the seal cylindrical portion is easily deformed radially inward together with the sub seal lip, and is easily brought into slidable contact with the outer peripheral surface of the rotating body. Therefore, an increase in the tightening force of the main seal lip applied to the rotary body can be effectively suppressed.
Drawings
Fig. 1 is a partial sectional view of a sealing device according to a first embodiment of the present invention.
Fig. 2 is an enlarged cross-sectional view of the seal cylinder portion, the primary seal lip, and the secondary seal lip of the sealing device of fig. 1 in an initial state.
Fig. 3 is an enlarged cross-sectional view of the seal cylinder portion, the primary seal lip, and the secondary seal lip in a pressure applied state.
Fig. 4 is a table showing parameters used in an analysis simulation for calculating a relationship between a position of the sub seal lip with respect to the main seal lip in an initial state and a contact width of the main seal lip with the rotary shaft in a pressure applied state, and a simulation result.
Fig. 5 is a graph showing the results of the analysis simulation.
Fig. 6 is a partial sectional view of a sealing device according to a second embodiment of the present invention.
1 sealing device
2 casing
2A hole
4 rotating shaft (rotating body)
10 cylindrical mounting part
12 sealing cylinder part
14 connecting ring part
16 primary sealing lip
16c lip
18 pairs of sealing lips
18c lip
22 hoop spring
30 sealing device
32 auxiliary seal
38 auxiliary lip
Detailed Description
Hereinafter, various embodiments according to the present invention will be described with reference to the drawings. The scale of the drawings is not necessarily exact, and some features may be exaggerated or omitted.
The sealing device according to an embodiment is used for sealing grease in a housing inner space of a gear reducer for driving a link of an articulated robot.
First embodiment
As shown in fig. 1, a sealing device 1 according to a first embodiment seals a gap between a housing 2 of a gear reducer and a rotary shaft (rotary body) 4 disposed in a hole 2A of the housing 2, and separates an internal space of the housing 2 from the atmosphere. The rotation shaft 4 is a shaft for driving a link (e.g., an arm) of the robot. The rotary shaft 4 is rotatably supported by a bearing, not shown, and is coaxially disposed in the hole 2A. The rotating shaft 4 may be the final output shaft of a gear reducer, but may be another rotating body.
The rotary shaft 4 is cylindrical, the bore 2A is circular in cross-section, and the seal 1 is annular, but only the left half of these are shown in fig. 1.
The housing 2 and the rotary shaft 4 are shown in dashed lines. In a use state in which the sealing device 1 is disposed in a gap between the housing 2 and the rotary shaft 4, the sealing device 1 is compressively deformed in a radial direction.
The sealing device 1 has a composite structure comprising an elastic ring 6 and a rigid ring 8. The elastic ring 6 is formed of an elastic material, such as an elastomer. The rigid ring 8 is formed of a rigid material, such as metal, to reinforce the elastic ring 6. The rigid ring 8 has an L-shaped cross section, and includes a sleeve 8A and an annular portion 8B extending radially inward from an end portion on the atmosphere side of the sleeve 8A.
The sealing device 1 includes an attachment cylindrical portion 10, a seal cylindrical portion 12, a connecting annular portion 14, a main seal lip 16, a sub seal lip 18, and a dust lip 20.
The mounting cylindrical portion 10 is mounted on the housing 2. The attachment method is not limited, and for example, the attachment cylindrical portion 10 may be interference-fitted into the hole 2A. The attachment cylindrical portion 10 includes an elastic ring 6 and a rigid ring 8. More specifically, in the attachment cylindrical portion 10, the elastic ring 6 is fixed to the entire outer peripheral surface of the sleeve 8A of the rigid ring 8, and is also fixed to the entire inner peripheral surface of the sleeve 8A of the rigid ring 8. Therefore, the attachment cylindrical portion 10 has an elastic portion 10A that covers the entire outer peripheral surface of the sleeve 8A and an elastic portion 10B that covers the entire inner peripheral surface of the sleeve 8A. However, it is not indispensable to cover the inner peripheral surface of the sleeve 8A with an elastic material.
The seal cylindrical portion 12 is constituted only by the elastic ring 6, and is disposed radially inward of the attachment cylindrical portion 10. The seal cylindrical portion 12 radially overlaps the attachment cylindrical portion 10.
The connecting annular portion 14 radially connects the end of the attachment cylindrical portion 10 on the atmosphere side and the end of the seal cylindrical portion 12 on the atmosphere side. The connecting ring portion 14 includes an elastic ring 6 and a rigid ring 8. More specifically, in the connecting annular portion 14, the elastic ring 6 is fixed to the entire surface of the annular portion 8B of the rigid ring 8 on the atmosphere side, and is also fixed to a part of the surface of the rigid ring 8 on the internal space side of the annular portion 8B. Therefore, the connecting annular portion 14 includes an elastic portion 14a covering the entire atmosphere side of the annular portion 8B and an elastic portion 14B covering a part of the surface of the internal space side of the annular portion 8B.
The primary seal lip 16 is a protrusion protruding from the inner circumferential surface of the seal cylindrical portion 12, and includes: a grease-side inclined surface 16a disposed on the internal space side; an atmosphere-side inclined surface 16b disposed on the atmosphere side; and a lip 16c that is located at a boundary between the grease-side inclined surface 16a and the atmosphere-side inclined surface 16b and extends in the circumferential direction. The grease-side inclined surface 16a has a truncated-cone side shape, and is inclined away from the rotation axis 4 as the distance from the lip 16c increases. The atmosphere-side inclined surface 16b also has a truncated-cone side shape, and is inclined away from the rotation axis 4 as it goes away from the lip 16 c. In a use state in which the sealing device 1 is disposed in a gap between the housing 2 and the rotary shaft 4, the lip 16c of the main seal lip 16 and its vicinity are always in slidable contact with the outer peripheral surface of the rotary shaft 4.
The sub seal lip 18 is also a projection projecting from the inner peripheral surface of the seal cylindrical portion 12. The sub seal lip 18 is disposed on the atmospheric side of the main seal lip 16, and has an inner diameter larger than the inner diameter of the main seal lip 16. The sub seal lip 18 has: a grease-side inclined surface 18a disposed on the internal space side; an atmosphere-side inclined surface 18b disposed on the atmosphere side; and a lip 18c that is located at a boundary between the grease-side inclined surface 18a and the atmosphere-side inclined surface 18b, and extends in the circumferential direction. The grease-side inclined surface 18a has a truncated-cone side shape, and is inclined away from the rotation axis 4 as the distance from the lip 18c increases. The atmosphere-side inclined surface 18b also has a truncated-cone side shape, and is inclined away from the rotation axis 4 as it goes away from the lip 18 c. In a use state in which the sealing device 1 is disposed in the gap between the housing 2 and the rotary shaft 4, the sub seal lip 18 does not contact the outer peripheral surface of the rotary shaft 4 when no pressure is applied. That is, a gap is formed between the sub seal lip 18 and the outer peripheral surface of the rotary shaft 4. However, when pressure is applied to the seal cylindrical portion 12 from the outside, the lip edge 18c of the sub seal lip 18 and its vicinity slidably contact the outer peripheral surface of the rotary shaft 4.
The dust lip 20 is a truncated cone-shaped plate extending obliquely radially inward from the inner peripheral surface of the connecting annular portion 14 and toward the atmosphere. The dust lip 20 has a function of suppressing the intrusion of foreign matters (including water or dust) from the atmosphere side to the internal space side. In this embodiment, in order to reduce the torque applied to the rotating shaft 4 by the sealing device 1, the dust lip 20 does not contact the rotating shaft 4. However, in order to further reduce the intrusion of foreign matter, the tip of the dust lip 20 may be slidably brought into contact with the outer peripheral surface of the rotary shaft 4.
The primary seal lip 16, the secondary seal lip 18 and the dust lip 20 are constituted only by the elastic ring 6.
A circumferential groove 21 is formed in the outer circumferential surface of the seal cylindrical portion 12, and a garter spring 22 is disposed in the circumferential groove 21. The garter spring 22 presses the main seal lip 16 and the dust lip 20 radially inward.
Fig. 2 and 3 are enlarged sectional views of the seal cylinder portion 12, the primary seal lip 16, and the secondary seal lip 18, respectively. Fig. 2 shows an initial state in which the sealing device 1 is not disposed in the gap between the housing 2 and the rotary shaft 4 and no pressure is applied to the seal cylindrical portion 12 from the outside.
On the other hand, fig. 3 shows a state in which the sealing device 1 is disposed in a gap between the housing 2 and the rotating shaft 4 and a pressure is applied to the sealing cylinder portion 12 from the outside (hereinafter, this state is referred to as a "pressure application state"). Specifically, in fig. 3, the seal cylindrical portion 12, the primary seal lip 16, and the secondary seal lip 18 in the initial state (the state of fig. 2) are indicated by broken lines, and the seal cylindrical portion 12, the primary seal lip 16, and the secondary seal lip 18 in the state of being displaced radially inward by the pressure P are indicated by solid lines. If the pressure of the grease in the internal space increases, a pressure P is applied to the seal cylindrical portion 12 from the outside. Specifically, when grease exists around the seal cylindrical portion 12, the grease applies a pressure P to the seal cylindrical portion 12. Even when grease is not present around the seal cylindrical portion 12, the pressure P is applied to the seal cylindrical portion 12 from the air around the seal cylindrical portion 12 pressed by the grease.
When the seal device 1 is disposed in the gap between the housing 2 and the rotary shaft 4, the main seal lip 16 is always in contact with the outer peripheral surface of the rotary shaft 4, and therefore deforms as compared with the initial state even in the absence of the pressure P. The main seal lip 16 is pressed against the outer peripheral surface of the rotary shaft 4 by the pressure P and is largely deformed. Therefore, the tightening force of the primary seal lip 16 on the rotary shaft 4 increases. The sub seal lip 18 does not contact the outer peripheral surface of the rotary shaft 4 even when the pressure P is not applied in the use state, but slidably contacts the outer peripheral surface of the rotary shaft 4 when the pressure P is applied to the seal cylindrical portion 12 from the outside, so that the increase in the tightening force applied to the rotary shaft 4 by the main seal lip 16 is suppressed. Therefore, wear of the main seal lip 16 can be reduced, and an increase in torque applied to the rotary shaft 4 can be suppressed.
As shown in fig. 2, the minimum thickness a of the atmospheric-side end portion of the seal cylinder portion 12 is 1/2 or less of the length B from the connecting annular portion 14 (specifically, the elastic portion 14B) to the lip edge 16c of the main seal lip 16 in the axial direction of the sealing device 1. The connecting annular portion 14 is formed of an elastic material and a rigid material and has high rigidity, but the seal cylindrical portion 12 supported by the connecting annular portion 14 is formed of only an elastic material and has low rigidity, and the minimum thickness a of the end portion on the atmosphere side of the seal cylindrical portion 12 is small. Therefore, when the pressure P is applied to the seal cylindrical portion 12 from the outside, the seal cylindrical portion 12 is easily deformed radially inward together with the sub seal lip 18, and is easily brought into slidable contact with the outer peripheral surface of the rotary shaft 4. Therefore, an increase in the tightening force of the main seal lip 16 to the rotary shaft 4 can be effectively suppressed.
As shown in fig. 2 and 3, the sub seal lip 18 is disposed in a region overlapping the garter spring 22 in the radial direction. In fig. 2, a region C overlaps the tension spring 22 in the radial direction, and a lip 18C of the sub seal lip 18 is disposed in the region C. As compared with the case where the sub seal lip 18 is not disposed in the region overlapping the garter spring 22 in the radial direction, the sub seal lip 18 is easily brought into slidable contact with the outer peripheral surface of the rotary shaft 4 by the compression force of the garter spring 22. Therefore, an increase in the tightening force of the main seal lip 16 to the rotary shaft 4 can be effectively suppressed.
In order to investigate an appropriate positional relationship of the sub seal lip 18 with respect to the main seal lip 16, the inventors calculated a relationship between a position of the sub seal lip 18 with respect to the main seal lip 16 in an initial state (the state of fig. 2) and a contact width W of the main seal lip 16 with the rotary shaft 4 in a pressure applied state (the state of fig. 3) by an analytical simulation using a Finite Element Method (FEM). The contact width W is preferably small in consideration of the torque applied to the rotary shaft 4 by the seal device 1 and the wear of the main seal lip 16.
In the analysis simulation, the pressure P in the pressure applied state was set to 0.04 MPa. The outer diameter D of the rotary shaft 4 was set to 49.8 mm. Inner diameter d of lip 16c of main seal lip 16 in initial state1Set to be smaller than 49.4mm of the outer diameter D of the rotary shaft 4.
Further, a distance (inter-lip distance) L between the lip 16c of the main seal lip 16 and the lip 18c of the sub seal lip 18 in the axial direction of the seal device 1 in the initial state and an inner diameter d of the lip 18c of the sub seal lip 18 in the initial state are changed2. The inner diameter d of the valley portion 24, which is the boundary between the atmospheric-side inclined surface 16b of the primary seal lip 16 and the grease-side inclined surface 18a of the secondary seal lip 18 in the initial state3Changed to be larger than the inner diameter d of the lip 18c2Is large.
Fig. 4 shows parameters used in the analysis simulation and the simulation result. Following the inner diameter d of the lip 18c in the initial state2The radial distance G between the lip 16c and the lip 18c in the initial state changes, and the gap G between the lip 18c and the rotary shaft 4 in the initial state also changes. Tan θ, which is the ratio of the radial distance g between the lips 16c and 18c in the initial state to the inter-lip distance L in the axial direction, also changes. θ is an inclination angle of an imaginary conical generatrix connecting the lip 16c and the lip 18c in the initial state with respect to the axis of the sealing device 1.
As is apparent from fig. 4, the contact width W of the main seal lip 16 and the rotary shaft 4 in the pressure applied state increases as the distance L between the lips in the axial direction in the initial state increases. the relationship between the change in tan θ and the contact width W is not significant.
Fig. 5 shows a relationship between the distance L between lips in the axial direction in the initial state and the contact width W in the pressure applied state. As is clear from fig. 5, the rate of increase in the contact width W is small when the inter-lip distance L is 0.8mm to 1.2mm, but is large when the inter-lip distance L exceeds 1.2 mm. That is, if the inter-lip distance L exceeds 1.2mm, the contact width W of the main seal lip 16 and the rotary shaft 4 in the use state becomes significantly large, and the torque applied to the rotary shaft 4 and the wear of the main seal lip 16 increase significantly. If the inter-lip distance L is 1.2mm or less, an increase in torque applied to the rotary shaft 4 and wear of the main seal lip 16 can be suppressed. Therefore, the distance from the lip 16c of the main seal lip 16 to the lip 18c of the sub seal lip 18 in the axial direction of the sealing device 1 in the initial state is preferably 1.2mm or less.
Second embodiment
Fig. 6 is a partial sectional view of a sealing device 30 according to a second embodiment of the present invention. In fig. 6, the same reference numerals are used to indicate the components already described, and the detailed description of these components will not be repeated.
The sealing device 30 has an auxiliary seal 32 in addition to having a similar basic structure to the sealing device 1 according to the first embodiment. The auxiliary seal 32 is detachable from the basic structure and is disposed inside the mounting cylindrical portion 10 of the basic structure.
The secondary seal 32 has a composite structure including an elastomeric ring 34 and a rigid ring 36. The elastic ring 34 is formed of an elastic material, such as an elastomer. Rigid ring 36 is formed of a rigid material, such as metal, to reinforce elastomeric ring 34. The rigid ring 36 has a substantially L-shaped cross section, and includes a sleeve 36A and an annular portion 36B extending radially inward from an end portion of the sleeve 36A on the inner space side. The sleeve 36A of the rigid ring 36 is fitted into the elastic portion 10B of the attachment cylindrical portion 10 by interference fit.
The elastic ring 34 has an auxiliary lip 38, and the auxiliary lip 38 is disposed radially inward of the annular portion 36B of the rigid ring 36. The auxiliary lip 38 is disposed on the inner space side of the primary seal lip 16 of the basic structure. The front end of the auxiliary lip 38 slidably contacts the outer peripheral surface of the rotary shaft 4.
According to this embodiment, the auxiliary seal 32 can prevent the grease disposed in the internal space from leaking to the atmosphere. However, since there may be a slight gap between the auxiliary lip 38 and the outer peripheral surface of the rotary shaft 4, when the pressure of the grease in the internal space increases, the pressure P can be applied to the seal cylindrical portion 12 from the outside. Further, since the grease in the internal space can flow over the auxiliary lip 38 and enter the atmosphere as the auxiliary lip 38 wears, the pressure P can be applied to the seal cylindrical portion 12 from the outside in this case as well. As in the first embodiment, by forming the seal cylindrical portion 12, the primary seal lip 16, and the secondary seal lip 18, it is possible to suppress an increase in the tightening force applied to the rotary shaft 4 by the primary seal lip 16, reduce wear of the primary seal lip 16, and suppress an increase in the torque applied to the rotary shaft 4.
Modification example
While the present invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the present invention as defined by the appended claims. Such alterations, changes, and modifications are intended to be included within the scope of the invention.
For example, in the above embodiment, the sealing device seals the gap between the housing 2 of the gear reducer and the rotating shaft 4 disposed in the hole 2A provided in the housing 2 in order to seal grease in the internal space of the housing of the gear reducer for driving the link of the articulated robot. However, the sealing device may also be used to seal grease in the interior space of the housing of other gear reducers.
The sealing device may be used to seal a gap between the housing and a rotating body rotating at a low speed in a hole provided in the housing in order to seal grease in an internal space of the housing of a device other than the gear reducer. For example, the sealing device may be used to seal a gap between a rotating shaft of a turntable of a precision machine and a housing of the rotating shaft. Alternatively, the sealing device may be used to seal a gap between the rotation shaft of the rotary camera or the rotary blower and the housing of the rotation shaft.
Another member (for example, a sleeve) may be disposed around the rotary shaft 4 such that the main seal lip 16 slidably contacts the outer peripheral surface of the member, the sub seal lip 18 does not contact the outer peripheral surface of the member when no pressure is applied thereto, and the sub seal lip slidably contacts the outer peripheral surface of the member when pressure is applied from the outside to the seal cylindrical portion 12. In this case, the combination of the rotary shaft 4 and the member may be regarded as a rotating body.
The manner of the present invention is also described in the following numbered schemes.
the sealing device has:
an attachment cylindrical portion attached to the housing;
a seal cylindrical portion disposed radially inward of the attachment cylindrical portion;
a connecting annular portion connecting an end portion of the attachment cylindrical portion on an atmosphere side and an end portion of the seal cylindrical portion on the atmosphere side in a radial direction;
a main seal lip projecting from an inner peripheral surface of the seal cylindrical portion and slidably contacting an outer peripheral surface of the rotating body; and
a sub seal lip protruding from an inner peripheral surface of the seal cylindrical portion and disposed on an atmospheric side of the main seal lip, an inner diameter of the sub seal lip being larger than an inner diameter of the main seal lip,
the sub seal lip does not contact the outer peripheral surface of the rotating body when no pressure is applied, and slidably contacts the outer peripheral surface of the rotating body when pressure is applied to the seal cylindrical portion from the outside,
the seal cylinder portion, the primary seal lip, and the secondary seal lip are formed only of an elastic material,
the mounting cylindrical portion and the coupling annular portion are formed of the elastic material and a rigid material,
the minimum thickness of the end portion on the atmosphere side of the seal cylindrical portion is 1/2 or less of the length from the connecting annular portion to the lip edge of the main seal lip in the axial direction of the sealing device.
further comprising a garter spring disposed around the seal cylinder portion,
the secondary seal lip is disposed in a region overlapping the tension spring in a radial direction.
According to this aspect, the secondary seal lip is more likely to slidably contact the outer peripheral surface of the rotating body by the compression force of the garter spring than when the secondary seal lip is not disposed in the region overlapping the garter spring in the radial direction. Therefore, an increase in the tightening force of the main seal lip applied to the rotary body can be effectively suppressed.
Scheme 3. the sealing device according to scheme 1 or 2, characterized in that,
the distance from the lip edge of the main seal lip to the lip edge of the auxiliary seal lip in the axial direction of the seal device is 1.2mm or less.
If the distance exceeds 1.2mm, the contact width of the main seal lip with the rotating body in the use state becomes significantly large, and the torque applied to the rotating body and the abrasion of the main seal lip are significantly increased. If the distance is 1.2mm or less, an increase in torque applied to the rotating body and wear of the main seal lip can be suppressed.
further comprising an auxiliary seal disposed inside the mounting cylindrical portion,
the auxiliary seal member has: a sleeve fitted into the mounting cylindrical portion; and an auxiliary lip which is disposed radially inward of the sleeve and radially inward of the main seal lip and on the inner space side of the main seal lip, and which slidably contacts the outer peripheral surface of the rotating body.
According to this aspect, the auxiliary seal can suppress leakage of the grease disposed in the internal space to the atmosphere.
Claims (4)
1. A sealing device for sealing a gap between a housing and a rotating body disposed in a hole provided in the housing and separating an internal space of the housing from an atmosphere side,
the sealing device has:
an attachment cylindrical portion attached to the housing;
a seal cylindrical portion disposed radially inward of the attachment cylindrical portion;
a connecting annular portion connecting an end portion of the attachment cylindrical portion on an atmosphere side and an end portion of the seal cylindrical portion on the atmosphere side in a radial direction;
a main seal lip projecting from an inner peripheral surface of the seal cylindrical portion and slidably contacting an outer peripheral surface of the rotating body; and
a sub seal lip protruding from an inner peripheral surface of the seal cylindrical portion and disposed on an atmospheric side of the main seal lip, an inner diameter of the sub seal lip being larger than an inner diameter of the main seal lip,
the sub seal lip does not contact the outer peripheral surface of the rotating body when no pressure is applied, and slidably contacts the outer peripheral surface of the rotating body when pressure is applied to the seal cylindrical portion from the outside,
the seal cylinder portion, the primary seal lip, and the secondary seal lip are formed only of an elastic material,
the mounting cylindrical portion and the coupling annular portion are formed of the elastic material and a rigid material,
the minimum thickness of the end portion on the atmosphere side of the seal cylindrical portion is 1/2 or less of the length from the connecting annular portion to the lip edge of the main seal lip in the axial direction of the sealing device.
2. The sealing device of claim 1,
further comprising a garter spring disposed around the seal cylinder portion,
the secondary seal lip is disposed in a region overlapping the tension spring in a radial direction.
3. Sealing device according to claim 1 or 2,
the distance from the lip edge of the main seal lip to the lip edge of the auxiliary seal lip in the axial direction of the seal device is 1.2mm or less.
4. Sealing device according to claim 1 or 2,
further comprising an auxiliary seal disposed inside the mounting cylindrical portion,
the auxiliary seal member has: a sleeve fitted into the mounting cylindrical portion; and an auxiliary lip which is disposed radially inward of the sleeve and radially inward of the main seal lip and on the inner space side of the main seal lip, and which slidably contacts the outer peripheral surface of the rotating body.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019-087419 | 2019-05-07 | ||
| JP2019087419A JP7378958B2 (en) | 2019-05-07 | 2019-05-07 | sealing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212251132U true CN212251132U (en) | 2020-12-29 |
Family
ID=73044927
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020470609.6U Active CN212251132U (en) | 2019-05-07 | 2020-04-02 | Sealing device |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP7378958B2 (en) |
| CN (1) | CN212251132U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117052905A (en) * | 2023-10-11 | 2023-11-14 | 万向钱潮股份公司 | Sealing device for universal joint |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2526784Y2 (en) * | 1993-03-31 | 1997-02-19 | 株式会社荒井製作所 | Oil seal with auxiliary lip |
| JPH1194093A (en) * | 1997-09-19 | 1999-04-09 | Nok Corp | Sealing device |
| JP2003240126A (en) | 2002-02-15 | 2003-08-27 | Koyo Sealing Techno Co Ltd | Seal ring |
| JP2006083955A (en) | 2004-09-16 | 2006-03-30 | Arai Pump Mfg Co Ltd | Sealing device |
| CN202612644U (en) | 2012-05-07 | 2012-12-19 | 李加宝 | Oil seal ring of high-pressure plunger pump |
| JP2015048855A (en) | 2013-08-29 | 2015-03-16 | 光洋シーリングテクノ株式会社 | Seal member |
| JP6290657B2 (en) | 2014-03-07 | 2018-03-07 | 光洋シーリングテクノ株式会社 | Sealing device |
-
2019
- 2019-05-07 JP JP2019087419A patent/JP7378958B2/en active Active
-
2020
- 2020-04-02 CN CN202020470609.6U patent/CN212251132U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117052905A (en) * | 2023-10-11 | 2023-11-14 | 万向钱潮股份公司 | Sealing device for universal joint |
| CN117052905B (en) * | 2023-10-11 | 2023-12-29 | 万向钱潮股份公司 | Sealing device for universal joint |
Also Published As
| Publication number | Publication date |
|---|---|
| JP7378958B2 (en) | 2023-11-14 |
| JP2020183776A (en) | 2020-11-12 |
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