JP7203572B2 - sealing device - Google Patents

Description

The present invention relates to sealing devices.

For example, an automobile engine is provided with an oil seal (sealing device) that is arranged around a crankshaft (rotating shaft) to seal lubricating oil in a crankcase. One type of sealing device for an engine has a rotating seal member called a slinger attached to the crankshaft and a stationary seal member attached to the crankcase. The slinger has a cylindrical sleeve attached to the outer peripheral surface of the crankshaft and an annular flange extending radially outward from the sleeve. The stationary seal member has a main lip and a dust lip that slidably contact the slinger. The main lip contacts the flange and the dust lip contacts the outer peripheral surface of the sleeve (Patent Document 1).

JP 2018-91372 A

In this type of sealing device, lubricating oil may pass between the main lip and the flange of the slinger, for example, when the rotating shaft rotates at high speed. Lubricating oil that has passed through is desirably sent back to the outside of the main lip.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a sealing device capable of efficiently sending lubricating oil that has passed through the main lip back to the outside of the main lip.

A sealing device according to an aspect of the present invention includes a cylindrical sleeve, a slinger having an annular flange extending radially outwardly from the sleeve, and a stationary seal member attached to the housing and in contact with the slinger. have The stationary seal member has an annular main lip formed from a resilient material that slidably contacts the atmosphere side surface of the flange of the slinger and seals lubricating oil within the housing. The surface of the flange of the slinger is formed with an inclined portion located toward the atmosphere side toward the radially inner side, and the inclined portion has a spiral slope surface.

In this embodiment, when lubricating oil droplets floating past the main lip come into contact with the sloped portion of the slinger flange, they adhere to the spiral slope surface of the sloped portion. The slinger rotates together with the rotating shaft, and the oil droplets adhering to the spiral slope surface move radially outward along the spiral as the slinger rotates. Therefore, it is possible to efficiently send the oil droplets back to the radially outer side and thus to the outer side of the main lip as the slinger rotates.

1 is a partial cross-sectional view showing the sealing device according to the first embodiment of the invention in use; FIG. Figure 2 is an enlarged partial cross-sectional view of the closure of Figure 1 in use; Figure 2 is a front view of a slinger of the sealing device of Figure 1; Figure 4 is a perspective view of the slinger of Figure 3; 4 is an enlarged perspective view, partially broken away, of the slinger of FIG. 3; FIG.

Embodiments according to the present invention will be described below with reference to the accompanying drawings.

A sealing device according to an embodiment of the present invention is an oil seal arranged around a crankshaft to seal lubricating oil in a crankcase.

As shown in FIG. 1 , a sealing device 1 seals a gap between a crankcase (housing) 2 and a crankshaft (rotating shaft) 4 disposed in the crankcase 2 to lubricate the crankcase 2 . Prevent oil leakage. The sealing device 1 has an annular shape centered on the rotational axis Ax of the crankshaft 4, but only the upper part of the sealing device 1 is shown in FIG.

The sealing device 1 has a slinger 6 and a stationary sealing member 8 . A slinger 6 is a rotary seal member attached to the crankshaft 4 . The stationary seal member 8 is a stationary member attached to the crankcase 2 .

The slinger 6 is made of rigid material, for example metal. The slinger 6 has a cylindrical sleeve 10 and an annular flange 12 . The sleeve 10 is attached to the outer peripheral surface of the crankshaft 4 by, for example, an interference fit. The flange 12 extends radially outwardly from the lubricant-side end of the sleeve 10 . Since the slinger 6 is attached to the crankshaft 4 , it rotates together with the crankshaft 4 around the rotation axis Ax.

The stationary seal member 8 has a double structure having an elastic ring 14 made of an elastic material such as an elastomer and a single rigid ring 16 made of a rigid material such as metal that reinforces the elastic ring 14 . A part of the rigid ring 16 is embedded in the elastic ring 14 and is in close contact with the elastic ring 14 .

The rigid ring 16 has an outer annular portion 16a and a curved disk portion 16b extending radially inward from the air-side end of the annular portion. The annular portion 16a and the disc portion 16b are integrally formed.

The elastic ring 14 has an annular portion 14a, a disk portion 14b, a block portion 14c, a main lip 18, a dust lip 20, and an intermediate lip 22. The annular portion 14a, disk portion 14b, block portion 14c, main lip 18, dust lip 20, and intermediate lip 22 are integrally formed. The annular portion 14a is fixed to the outer peripheral surface of the annular portion 16a of the rigid ring 16, and the disk portion 14b is fixed to the surface of the disk portion 16b of the rigid ring 16 on the atmosphere side. The block portion 14c is an annular portion arranged radially inside the disc portion 14b and fixed to the inner end of the disc portion 16b so as to cover the inner end thereof.

The circular ring portion 14 a of the elastic ring 14 and the circular ring portion 16 a of the rigid ring 16 constitute a mounting portion that is mounted on the crankcase 2 . Specifically, the annular portions 14a and 16a are attached to the shaft hole of the crankcase 2 by interference fit, for example. However, only the annular portion 14a may be fitted into the shaft hole of the crankcase 2 with an interference fit, or only the annular portion 16a may be fitted into the shaft hole of the crankcase 2 with an interference fit.

The main lip 18 is an annular ring extending obliquely from the block portion 14 c toward the radially outer side and toward the lubricating oil side. of lubricating oil.

The dust lip 20 is an annular ring extending obliquely from the block portion 14 c toward the radially inner side and toward the atmosphere side, and slidably contacts the outer peripheral surface of the sleeve 10 of the slinger 6 . The dust lip 20 prevents foreign matter (such as water and dust) from entering the lubricating oil side from the atmosphere side.

The intermediate lip 22 is an annular ring extending from the block portion 14c to the lubricating oil side. Lubricating oil may pass through the main lip 18 from the lubricating oil side and enter the space 24 defined by the main lip 18 , the dust lip 20 , the sleeve 10 and the flange 12 . Intermediate lip 22 collects oil droplets present in space 24 . Specifically, oil droplets splashed by the rotation of the slinger 6 adhere to the inner surface 18 a of the main lip 18 . Since the stationary seal member 8 and thus the main lip 18 and the intermediate lip 22 are stationary, oil droplets adhering to the inner surface 18a of the main lip 18 above the rotation axis Ax of the crankshaft 4 are deposited on the outer peripheral surface of the intermediate lip 22. 22a. The oil droplets received by the outer peripheral surface 22a of the intermediate lip 22 drop onto the inner surface 18a of the main lip 18 below the rotation axis Ax. Below the rotation axis Ax of the crankshaft 4, the oil droplets adhering to the inner surface 18a of the main lip 18 are splashed by the rotation of the slinger 6 and returned to the lubricating oil side space. The illustrated intermediate lip 22 extends parallel to the rotation axis Ax, but may be inclined or curved with respect to the rotation axis Ax. The illustrated intermediate lip 22 does not contact the slinger 6, but may.

As shown in FIGS. 2 to 5, two sets of spiral structures 30, 34 are formed on the air-side surface 12a of the flange 12 of the slinger 6. As shown in FIGS. A set of spiral structures 30 has a plurality of helical (spiral) grooves 31 disclosed in JP-A-2018-91372 and JP-A-2014-084934. Another set of spiral structures 34 are arranged radially inward of the spiral structures 30 .

In the drawings, the reduced scale does not necessarily represent the product of the embodiment accurately, and some dimensions may be exaggerated. In particular, the details of the spiral structures 30, 34 are not necessarily shown precisely in the drawings for ease of understanding.

As shown in FIG. 2 , the spiral groove 31 of the spiral structure 30 arranged radially outward of the atmosphere-side surface 12 a of the flange 12 includes the position where the tip of the main lip 18 contacts and the outer edge of the flange 12 . It is located in an area that extends to the vicinity. The spiral center of the groove 31 substantially coincides with the rotation axis Ax. The spiral groove 31 serves to send back the droplets D of lubricating oil that have passed through the main lip 18 and entered the space 24 from the space 24 to the outside of the main lip 18 in the radial direction as the slinger 6 rotates. . As shown in FIG. 3, when the slinger 6 rotates clockwise, each groove 31 is arranged on a spiral trajectory that progresses radially outward from the radially inner end 32 as it progresses counterclockwise. It is Although not shown, when the slinger 6 rotates counterclockwise, each groove 31 is arranged on a spiral trajectory that advances radially outward as it advances clockwise from the radially inner end. Therefore, as shown in FIG. 2, once the oil droplet D is caught in the spiral groove 31, the oil droplet D is conveyed radially outward as the slinger 6 rotates. The oil droplets D are also splashed outward in the radial direction by the airflow caused by the centrifugal force that accompanies the rotation of the slinger 6 .

Although two grooves 31 are shown in FIG. 3, the number of grooves 31 may be one or three or more. The interval and the number of turns of the grooves 31 are not limited to the illustrated example. Also, the outer spiral structure 30 is not absolutely essential.

As shown in FIGS. 2 and 5, the spiral structure 34 disposed radially inward of the air-side surface 12a of the flange 12 is formed on an inclined portion 36 formed on the air-side surface 12a of the flange 12. there is The inclined portion 36 is formed so as to be located closer to the atmosphere side toward the inner side in the radial direction.

The spiral structure 34 and thus the ramp 36 is a spiral sloped surface 38 that connects adjacent turns of the spiral on the sloped surface 38 (turns 38a and 38b are illustrated in FIGS. 2, 4 and 5). and a connecting surface 40 of . The center of the spiral of the slope surface 38 and the connecting surface 40 substantially coincides with the rotation axis Ax.

The spiral sloped surface 38 is substantially flat, but is slightly inclined in the circumferential direction so that the radially inward portion is closer to the atmosphere, so that between adjacent turns of the spiral sloped surface 38 has a step. The spiral connection surface 40 is this step, and is greatly inclined in the radial direction and slightly inclined in the circumferential direction.

As shown in FIG. 3 , when the slinger 6 rotates clockwise, the sloped surface 38 extends radially outward as it progresses counterclockwise from the radially inner end 42 to the radially outer end 44 . It is placed on an advancing spiral trajectory. Although not shown, when the slinger 6 rotates counterclockwise, the slope surface 38 follows a spiral locus that progresses radially outward as it progresses clockwise from the radially inner end to the radially outer end. placed above. That is, the spiral direction of the slope surface 38 is the same as the spiral direction of the spiral groove 31 . As shown in FIG. 2, once the oil droplets D adhere to the spiral slope surface 38, the oil droplets D are conveyed radially outward as the slinger 6 rotates.

Although one spiral slope surface 38 is shown in FIG. 3, the number of slope surfaces 38 may be two or more. The width and number of turns of the slope surface 38 are not limited to the illustrated example.

As shown in FIG. 2 , when droplets D of lubricating oil floating in the space 24 after passing through the main lip 18 come into contact with the inclined portion 36 of the flange 12 of the slinger 6 , the spiral slope surface 38 of the inclined portion 36 . Adhere to. The slinger 6 rotates together with the crankshaft 4, and the oil droplets D adhering to the spiral slope surface 38 move radially outward along the spiral as the slinger 6 rotates. Therefore, it is possible to efficiently send the oil droplets D back to the outside of the main lip 18 in the radial direction as the slinger 6 rotates.

In this embodiment, since the spiral groove 31 is provided on the radially outer side of the spiral slope surface 38, most of the oil droplets D conveyed radially outward on the slope surface 38 flow into the spiral groove. 31 and is transported outwards more efficiently by the spiral grooves 31 .

Although there are some oil droplets D that do not adhere to the slope surface 38 , the oil droplets D are splashed radially outward by the airflow caused by the centrifugal force associated with the rotation of the slinger 6 , and most of the oil droplets D remain on the main lip 18 . sent back to the outside of the

Modifications Although the embodiments of the present invention have been described above, the above description does not limit the present invention, and various modifications including deletion, addition, and replacement of constituent elements can be made within the technical scope of the present invention. Conceivable.

For example, the inner surface 18a of the main lip 18 may be formed with a plurality of screw projections disclosed in Japanese Patent No. 6196408. Such a threaded projection plays a role of returning the droplets of lubricating oil that have entered the space 24 to the outside of the main lip 18 in the radial direction from the space 24 as the slinger 6 rotates.

A plurality of protrusions for suppressing excessive deformation of the dust lip 20 disclosed in Japanese Patent Application Laid-Open No. 2014-084934 may be formed on the inner peripheral surface of the dust lip 20 . Such projections temporarily contact the outer peripheral surface of the sleeve 10 of the slinger 6 to temporarily create a gap between the tip of the dust lip 20 and the outer peripheral surface of the sleeve 10 when the interior of the space 24 becomes negative pressure. to occur.

The sealing device according to the above embodiment is an oil seal that is arranged around the crankshaft and seals lubricating oil in the crankcase. However, the present invention is not limited to the embodiments, for example an oil seal arranged around the shaft of the transmission to seal the lubricating oil in the housing of the transmission, an oil seal arranged around the shaft of the differential gear mechanism. It can also be used as an oil seal to seal the lubricating oil in the housing of the differential gear mechanism, and an oil seal that is arranged around the shaft of the motor and seals the lubricating oil in the housing of the motor.

Aspects of the invention are also described in the following numbered clauses.

Clause 1. A slinger having a cylindrical sleeve attached to the outer peripheral surface of a rotating shaft arranged in a housing, and an annular flange extending radially outward from the sleeve;
a stationary seal member attached to the housing and contacting the slinger;
The fixed sealing member is
an annular main lip formed of a resilient material slidably contacting the air-side surface of the flange of the slinger and sealing lubricating oil within the housing;
A sealing device according to claim 1, wherein the surface of the flange of the slinger is formed with an inclined portion located toward the atmosphere side toward the radially inner side, and the inclined portion has a spiral slope surface.

Clause 2. The inclined portion is arranged radially inward of a position where the main lip of the surface of the flange contacts,
The sealing device according to Clause 1, wherein at least one spiral groove is formed in the portion of the face of the flange where the main lip contacts.

In this case, since the spiral groove is provided radially outward of the spiral slope surface, most of the oil droplets conveyed radially outward on the slope surface are delivered to the spiral groove. , are conveyed outward more efficiently by the spiral grooves.

Article 3. The spiral direction of the slope surface is the same as the spiral direction of the groove.

1 sealing device 2 crankcase (housing)
4 crankshaft (rotating shaft)
6 Slinger 8 Fixed seal member 10 Sleeve 12 Flange 12a Air side surface 30 Spiral structure 31 Spiral groove 34 Spiral structure 36 Inclined portion 38 Spiral slope surface 40 Spiral connecting surface

Claims (5)

A slinger having a cylindrical sleeve attached to the outer peripheral surface of a rotating shaft arranged in a housing, and an annular flange extending radially outward from the sleeve;
a stationary seal member attached to the housing and contacting the slinger;
The fixed sealing member is
an annular main lip formed of a resilient material slidably contacting the air-side surface of the flange of the slinger and sealing lubricating oil within the housing;
The atmosphere-side surface of the flange of the slinger is formed with an inclined portion positioned toward the atmosphere side toward the radially inner side, the inclined portion having a spiral slope surface, and the spiral slope No circumferentially extending grooves or circumferentially extending protrusions are formed between adjacent turns of the face.
A sealing device characterized by: A slinger having a cylindrical sleeve attached to the outer peripheral surface of a rotating shaft arranged in a housing, and an annular flange extending radially outward from the sleeve;
a stationary seal member attached to the housing and contacting the slinger;
The fixed sealing member is
an annular main lip formed of a resilient material slidably contacting the air-side surface of the flange of the slinger and sealing lubricating oil within the housing;
The atmosphere-side surface of the flange of the slinger is formed with an inclined portion positioned toward the atmosphere side toward the radially inner side, the inclined portion having a spiral slope surface,
In a cross section including the central axis of the slinger, the plurality of windings of the spiral slope surface are formed stepwise so that the radially inner side is positioned closer to the atmosphere.
A sealing device characterized by: The inclined portion having the spiral slope surface is arranged radially inward from a position where the tip of the main lip of the atmosphere-side surface of the flange contacts.
The sealing device according to claim 1 or 2, characterized in that: A slinger having a cylindrical sleeve attached to the outer peripheral surface of a rotating shaft arranged in a housing, and an annular flange extending radially outward from the sleeve;
a stationary seal member attached to the housing and contacting the slinger;
The fixed sealing member is
an annular main lip formed of a resilient material slidably contacting the air-side surface of the flange of the slinger and sealing lubricating oil within the housing;
The atmosphere-side surface of the flange of the slinger is formed with an inclined portion positioned toward the atmosphere side toward the radially inner side, the inclined portion having a spiral slope surface,
The inclined portion having the spiral slope surface is arranged radially inward from a position where the tip of the main lip of the atmosphere-side surface of the flange contacts.
A sealing device characterized by: At least one spiral groove is formed at a position where the tip of the main lip contacts the air-side surface of the flange,
The spiral direction of the slope surface is the same as the spiral direction of the groove
The sealing device according to claim 3 or 4, characterized in that:

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