JP7029893B2 - Sealing device - Google Patents

Description

The present invention relates to a sealing device, for example, used as a rotary seal in an automobile-related field, and particularly as an engine seal in which lubricating oil is present in the machine.

Conventionally, as a sealing device used as an engine seal, for example, it is installed between an engine housing and a crankshaft in order to prevent the lubricating oil sealed in the machine from leaking to the outside of the machine. In this sealing device, a screw portion provided on the flange portion of the slinger exerts a pumping action when the crankshaft rotates, and seals the lubricating oil in the machine (see, for example, Patent Document 1).

As shown in FIG. 8, as such a sealing device 100, the slinger 101 mounted on the outer peripheral surface of the crankshaft 201 as a rotating shaft and rotating together with the crankshaft 201, and the slinger 101 mounted on the inner peripheral surface of the housing 202. The seal portion 102 is provided.

The slinger 101 includes a cylindrical portion 105 mounted on the outer peripheral surface of the crankshaft 201, and a flange portion 103 extending from the end portion of the cylindrical portion 105 on the machine A side to the outer peripheral side. The flange portion 103 has a hollow disk-shaped bulging portion 103e that bulges toward the inside A side, and a hollow disk-shaped bulging portion 103e that is bent toward the outside B side from the end portion on the outer peripheral side of the bulging portion 103e and then expands toward the outer peripheral side. It is provided with a disk portion 103f of.

In this sealing device 100, the main lip 111 of the sealing portion 102 is slidably brought into close contact with the outer surface 103a, which is the end surface on the outer B side in the axial direction of the disk portion 103f of the flange portion 103, so that the inside of the machine is slidable. It prevents the lubricating oil (oil) existing in A from leaking to the outside B.

In this sealing device 100, a plurality of screw grooves 104 are provided on the outer surface 103a of the disk portion 103f of the flange portion 103 in which the main lip 111 is slidably close to each other.

The thread grooves 104 are quaternary spiral grooves that are independently arranged at regular intervals and rotate clockwise from the inner diameter side to the outer diameter side corresponding to the rotation direction of the crankshaft 201. The start and end points of the groove are different. The thread groove 104 is formed on the outer surface 103a of the disk portion 103f of the flange portion 103 in the slinger 101, and the lip tip 111a of the main lip 111 of the seal portion 102 is in contact within the range of the four screw grooves 104. ..

Therefore, in the sealing device 100, even when the lubricating oil seeps into the space S surrounded between the slinger 101 and the sealing member 110 of the sealing portion 102, the flange portion 103 when the slinger 101 rotates together with the crank shaft 201 The action of shaking off the lubricating oil from the space S to the inside of the machine A side due to the centrifugal force of the (Hereinafter, this is also referred to as "screw action"). The effect of returning the lubricating oil from the space S to the inside A side by both the shake-off action and the screw action is called a pumping effect.

Japanese Unexamined Patent Publication No. 2014-129837

In the above-mentioned sealing device 100, in the case of a diesel engine in which the rotation speed of the crankshaft 201 rotates at a low speed of, for example, about 5000 rpm (revolution per minute) or less, the flange portion 103 of the slinger 101 and the lip tip 111a of the main lip 111 Lubricating oil does not seep out from the gap to the space S.

However, when the sealing device 100 is applied to a gasoline engine in which the crankshaft 201 rotates at a high speed of, for example, about 6000 rpm or more, lubricating oil flows into the space S from the gap between the flange portion 103 of the slinger 101 and the lip tip 111a of the main lip 111. There was a risk that the lubricating oil would ooze out and accumulate in the space S.

The present invention has been made in view of the above problems, and an object thereof is that the lubricating oil inside the machine is used with the flange portion of the slinger and the main lip even when the rotation speed of the rotating shaft is at a high speed of a predetermined value or higher. It is an object of the present invention to provide a sealing device capable of preventing the oil from seeping out from the gap and finally leaking.

In order to achieve the above object, in the present invention, the cylindrical portion mounted on the outer peripheral surface of the rotating shaft that rotates with respect to the housing, and the inner end portion of the cylindrical portion are perpendicular to the axis of the rotating shaft. The lubricating oil is sealed to the inside of the housing by slidably contacting the slinger having an annular flange portion extending in the above direction and the flat outer surface of the flange portion of the slinger, which is mounted on the housing. The flange portion is provided with a sealing portion having a main lip, and the flange portion has a groove on the outer surface thereof in a portion in contact with the main lip to exert a draining action of returning the lubricating oil to the inside of the housing during rotation. The main lip is characterized by having a curved shape that is entirely curved from the lip base end portion of the main lip toward the lip tip portion in contact with the outer surface of the flange portion.

In the present invention, the lip tip portion of the main lip is in surface contact with the portion of the flange portion that is in contact with the outer surface, and is gently from the outer surface from the lip tip portion to the lip base end portion. It is characterized by being separated.

The present invention is characterized in that the lip tip portion of the main lip is in contact with the grooved region of the flange portion.

According to the present invention, even when the rotation speed of the rotating shaft is at a high speed of a predetermined rotation speed or more, the lubricating oil inside the machine seeps out from the gap between the flange portion of the slinger and the main lip and finally leaks. It is possible to realize a sealing device that can prevent the slipping.

It is sectional drawing which shows the mounting state of the oil seal which concerns on 1st Embodiment of this invention. It is an enlarged sectional view which shows the structure of the single body of the oil seal which concerns on 1st Embodiment of this invention. It is a top view which shows the structure of the slinger which concerns on 1st Embodiment of this invention. It is a top view which shows the other structural example of the slinger which concerns on 1st Embodiment of this invention. It is sectional drawing which provides the explanation of the storage amount of the lubricating oil according to the contact angle between the conventional main lip and the flange part of a slinger. It is a top view which provides the explanation of the storage amount of the lubricating oil according to the contact angle between the main lip and the flange portion of the slinger in the oil seal which concerns on 1st Embodiment of this invention. It is an enlarged sectional view which shows the structure of the single body of the oil seal which concerns on 2nd Embodiment of this invention. It is an enlarged sectional view which shows the structure of the conventional sealing apparatus (oil seal).

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

<First Embodiment>
FIG. 1 is a cross-sectional view showing a mounted state of an oil seal according to the first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing the configuration of a single oil seal according to the first embodiment of the present invention. FIG. 3 is a plan view showing the configuration of the slinger according to the first embodiment of the present invention. FIG. 4 is a plan view showing another configuration example of the slinger according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view for explaining the amount of lubricating oil stored according to the contact angle between the conventional main lip and the flange portion of the slinger. FIG. 6 is a plan view for explaining the amount of lubricating oil stored according to the contact angle between the main lip and the flange portion of the slinger in the oil seal according to the first embodiment of the present invention.

Hereinafter, for convenience of explanation, the arrow a (see FIG. 1) direction is the outside in the axis x direction, and the arrow b (see FIG. 1) direction is the inside in the axis x direction. More specifically, the outside is the outside B side away from the engine, and the inside is the inside direction of the engine and the inside A side. Further, in the direction perpendicular to the axis x (hereinafter, also referred to as “diameter direction”), the direction away from the axis x (direction of arrow c in FIG. 1) is set as the outer peripheral side, and the direction closer to the axis x (arrow d in FIG. 1). Direction) is the inner circumference side.

<Oil seal configuration>
As shown in FIGS. 1 and 2, the oil seal 1 as a sealing device according to the embodiment of the present invention is used as a seal for an automobile engine (particularly a gasoline engine) in which lubricating oil is present in the cabin A, and is used in the cabin. The lubricating oil of A is prevented from leaking to the outside B, and foreign matter such as dust is prevented from entering from the outside B to the inside A.

The oil seal 1 is attached to the seal portion 10 mounted on the inner peripheral surface 202a, which is the surface on the inner peripheral side (direction of the arrow d) of the engine housing (hereinafter, also simply referred to as “housing”) 202, and the housing 202. A slinger 30 mounted on an outer peripheral surface 201a, which is a surface on the outer peripheral side (direction of arrow c) of the crankshaft 201 as a rotating shaft that rotates with respect to the crankshaft 201, is provided, and is configured by a combination thereof.

The seal portion 10 includes a reinforcing ring 20 and an elastic body portion 21 integrally formed with the reinforcing ring 20. The reinforcing ring 20 is made of an annular metal material centered on the axis x. Examples of the metal material of the reinforcing ring 20 include stainless steel and SPCC (cold rolled steel). On the other hand, as the elastic body of the elastic body portion 21, for example, there are various rubber materials. Examples of various rubber materials are synthetic rubbers such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluororubber (FKM).

The reinforcing ring 20 is manufactured by, for example, press working or forging, and the elastic body portion 21 is molded by cross-linking (vulcanization) molding using a molding die. At the time of this cross-linking molding, the reinforcing ring 20 is arranged in the molding die, the elastic body portion 21 is adhered to the reinforcing ring 20 by cross-linking (vulcanization) adhesion, and the elastic body portion 21 is integrated with the reinforcing ring 20. Is molded.

The reinforcing ring 20 has, for example, a substantially L-shaped cross section, includes a cylindrical portion 20a, an outer peripheral side disk portion 20b, a tapered portion 20c, and an inner peripheral side disk portion 20d, and has a cylindrical portion 20a and an outer peripheral side. The disk portion 20b, the tapered portion 20c, and the inner peripheral side disk portion 20d are all integrally formed.

In this case, the cylindrical portion 20a has a curved shape that bulges convexly toward the outer peripheral side (direction of arrow c). Further, the outer peripheral side disk portion 20b, the tapered portion 20c, and the inner peripheral side disk portion 20d form a substantially S-shaped flange portion as a whole.

The cylindrical portion 20a is a cylindrical portion extending substantially parallel to the axis x, and is fitted inside the inner peripheral surface 202a of the housing 202. The outer peripheral side disk portion 20b is a hollow disk-shaped portion extending in a direction substantially perpendicular to the axis x, that is, from the outer end (arrow a direction) of the cylindrical portion 20a toward the inner peripheral side (arrow d direction). .. The tapered portion 20c is a hollow disk-shaped portion extending diagonally from the end portion of the outer peripheral side disk portion 20b on the inner peripheral side (arrow d direction) toward the inner peripheral side (arrow d direction) and the inner side (arrow b direction). Is. The inner peripheral side disk portion 20d is a hollow disk-shaped portion extending further toward the inner peripheral side (arrow d direction) from the end portion of the tapered portion 20c on the inner peripheral side (arrow d direction).

In this case, the cylindrical portion 20a of the reinforcing ring 20 has a curved shape that bulges convexly toward the outer peripheral side (direction of arrow c), but is not limited to this, and is not limited to this, and is along the axis x. It may be a cylindrical portion that extends straight. Further, the reinforcing ring 20 is formed in a substantially S-shape by the outer peripheral side disk portion 20b, the tapered portion 20c, and the inner peripheral side disk portion 20d, but the outer peripheral side disk portion 20b, the tapered portion 20c, and the reinforcing ring 20 are formed in a substantially S shape. The inner peripheral side disk portion 20d may extend straight in a direction substantially perpendicular to the axis x.

The elastic body portion 21 is integrally attached to the reinforcing ring 20, and the reinforcing ring 20 is attached to the outside (direction of arrow a), a part of the outer peripheral side (direction of arrow c), and the inner peripheral side (direction of arrow d). Is integrally molded with the reinforcing ring 20 so as to cover the above.

The elastic body portion 21 covers the lip covering portion 21a that covers a part of the outer peripheral side (arrow c direction) of the cylindrical portion 20a of the reinforcing ring 20 and the outer peripheral side disk portion 20b of the reinforcing ring 20 from the outside (arrow a direction). The lip covering portion 21b, the lip covering portion 21c covering the tapered portion 20c of the reinforcing ring 20, the lip covering portion 21d covering the inner peripheral side disk portion 20d of the reinforcing ring 20 from the outside (direction of arrow a), and the lip covering portion 21d. It is provided with a lip waist portion 21e integrated with the main lip 22, a dust strip 23, and an intermediate lip 24 integrally formed with the lip waist portion 21e.

The lip waist portion 21e of the elastic body portion 21 is a portion located near the end portion of the inner peripheral side disk portion 20d of the reinforcing ring 20 on the inner peripheral side (direction of arrow d), and is a portion located near the end portion of the inner peripheral side disk portion 20, the main lip 22, the dust strip 23, and the elastic body portion 21. , The base of the intermediate lip 24.

The main lip 22 of the elastic body portion 21 is centered on an axis x extending diagonally from the inner end (arrow b direction) of the lip waist portion 21e toward the inner side (arrow b direction) and the outer peripheral side (arrow c direction). It is an annular lip portion, and the diameter is expanded from the inner peripheral side (arrow d direction) to the outer peripheral side (arrow c direction).

The width, that is, the thickness of the main lip 22 between the outer peripheral surface 22g, which is the outer peripheral side (direction of arrow c), and the inner peripheral surface 22u, which is the inner peripheral side (arrow d direction), is the lip waist portion 21e. It extends from the base end side to the tip end side with the same thickness. However, not limited to this, the outer peripheral surface 22g is not substantially parallel to the inner peripheral surface 22u, and the outer peripheral surface 22g is flat and inclined so that the width with the inner peripheral surface 22u gradually narrows toward the most advanced surface. It may be a surface. Similarly, the inner peripheral surface 22u may be a flat surface inclined so that the width of the inner peripheral surface 22u with the outer peripheral surface 22g gradually narrows toward the most advanced surface.

In this case, the main lip 22 is defined by an outer peripheral surface 22g, an inner peripheral surface 22u, and a cutting edge surface 22e. The most advanced surface 22e of the main lip 22 is the most advanced end surface of the main lip 22, and is a flat surface substantially perpendicular to the outer peripheral surface 22g and the inner peripheral surface 22u. However, the present invention is not limited to this, and the cutting edge surface 22e may be a rounded curved surface.

The lip base end side of the main lip 22 is provided with a lip base end portion 22n corresponding to a root portion protruding inward (in the direction of arrow b) from the lip waist portion 21e, and the lip tip end side of the main lip 22 is described later. It is provided with a lip tip portion 22p which is a portion in contact with the outer surface 33g of the flange portion 33 of the slinger 30.

That is, the main lip 22 includes a lip base end 22n, a lip tip 22p, and a lip curved portion 22w that connects the lip base 22n and the lip tip 22p with a smooth curve. In this case, the lip curved portion 22w of the main lip 22 is entirely curved so as to be concave on the inner peripheral side (direction of arrow d) from the lip base end portion 22n to the lip tip portion 22p. However, there is practically no clear boundary between the lip base end portion 22n, the lip tip portion 22p, and the lip curved portion 22w of the main lip 22.

The inner peripheral surface 22u of the main lip 22 is a contact surface that comes into contact with the outer surface 33g, which is the outer surface (direction of arrow a) of the flange portion 33 of the slinger 30, which will be described later. However, not all of the inner peripheral surface 22u comes into contact with the outer surface 33g of the flange portion 33, but a part of the inner peripheral surface 22u on the tip end side of the lip tip portion 22p comes into surface contact with the outer surface 33g. ..

The outer peripheral surface 22g of the main lip 22 is a non-contact surface that does not come into contact with the outer surface 33g, which is the outer surface (direction of arrow a) of the flange portion 33 of the slinger 30, which will be described later. The outer peripheral surface 22g of the main lip 22 is not limited to the outer surface 33g of the flange portion 33, and does not come into contact with any portion.

The lip base end portion 22n of the main lip 22 is a root portion of the main lip 22 protruding inward (in the direction of arrow b) from the lip waist portion 21e, and is curved from the lip base end portion 22n to the lip tip portion 22p. This is the starting point of.

The lip tip portion 22p of the main lip 22 is a portion that comes into contact with the outer surface 33g of the flange portion 33, and is a portion that becomes an end point when bending from the lip base end portion 22n to the lip tip portion 22p. Further, the lip tip portion 22p comes into surface contact with the outer surface 33g when the main lip 22 is pressed against the outer surface 33g of the flange portion 33 with a predetermined squeeze margin, and the lubricating oil (oil) present in the machine A is present. ) Is a part that prevents the space S from seeping out.

The lip curved portion 22w of the main lip 22 is the main curved portion that is most bent because the lip base end portion 22n and the lip tip portion 22p are connected by a smooth curve and the main lip 22 has an overall curved shape. be. That is, when the main lip 22 is pressed against the outer surface 33g of the flange portion 33 with a predetermined shrinkage, the lip curved portion 22w is mainly bent.

The dust strip 23 of the elastic body portion 21 extends diagonally from the end portion of the lip waist portion 21e on the inner peripheral side (arrow d direction) toward the outer side (arrow a direction) and the inner peripheral side (arrow d direction). It is an annular lip portion centered on the above, and the diameter is expanded from the outer peripheral side (direction of arrow c) to the inner peripheral side (direction of arrow d). The extending direction of the dust strip 23 is substantially opposite to the extending direction of the main lip 22.

The intermediate lip 24 of the elastic body portion 21 is located on the inner peripheral side (arrow d direction) of the main lip 22 and inside (arrow b direction) of the dust strip 23 in the lip waist portion 21e, and is located on the lip waist portion. It is an annular lip portion centered on the axis x that slightly extends inward (in the direction of arrow b) from the end on the inner peripheral side (direction of arrow d) of 21e. The intermediate lip 24 has a short lip length, and the tip of the lip does not come into contact with the slinger 30.

The slinger 30 is, for example, a metal plate-shaped member that rotates with the rotation of the crankshaft 201 in a state of being mounted on the outer peripheral surface 201a of the crankshaft 201, and includes a cylindrical portion 31 and a flange portion 33. .. The slinger 30 can be formed, for example, by bending a plate-shaped member.

The cylindrical portion 31 of the slinger 30 is a cylindrical portion extending substantially parallel to the axis x, and is mounted by being press-fitted and fixed to the outer peripheral surface 201a of the crankshaft 201 rotating with respect to the housing 202. The cylindrical portion 31 of the slinger 30 has an outer peripheral surface 31a which is a surface on the outer peripheral side (direction of arrow c), and the lip tip of the dust strip 23 of the elastic body portion 21 is slidable with respect to the outer peripheral surface 31a. Contact. This prevents foreign matter such as dust from entering the inside A from the outside B.

The flange portion 33 of the slinger 30 has a hollow disk-shaped bulging portion 33b bulging toward the inside A side and an outer peripheral side (arrow c) after being bent from the end portion of the bulging portion 33b on the outer peripheral side to the outer peripheral side B side. It is provided with a hollow disk-shaped disk portion 33a that extends in the direction).

The height of the bulging portion 33b of the flange portion 33 toward the outer peripheral side (direction of arrow c) is higher than the position of the lip tip of the intermediate lip 24, and the bulging portion 33b and the lip tip of the intermediate lip 24 face each other. It is arranged like this.

In this oil seal 1, the lip tip portion 22p of the main lip 22 of the elastic body portion 21 is slidable with respect to the outer surface 33g, which is the end surface on the outer B side in the axial direction of the disk portion 33a of the flange portion 33. The close contact prevents the lubricating oil (oil) existing in the machine A from leaking to the outside B.

In this oil seal 1, the lubricating oil G1 (FIG. 6) that has entered the space S is discharged to the outside A in the end region of the outer surface 33 g where the lip tip portion 22p of the main lip 22 is slidably close to each other. There are four spiral groove-shaped threaded grooves 34 used for this purpose.

The screw grooves 34 are independently arranged at regular intervals, and are four-equal spiral grooves that rotate clockwise from the inner diameter side to the outer diameter side corresponding to the rotation direction of the crankshaft 201. The start and end points of the groove are different. The thread groove 34 is formed on the outer surface 33g of the disk portion 33a of the flange portion 33 in the slinger 30, and the thin-walled tip portion 22p of the main lip 22 of the elastic body portion 21 comes into contact with each other within the range of the four screw grooves 34. ing.

As shown in FIG. 3, these four screw grooves 34 are formed at positions where their start points st are separated from each other by 90 degrees, and their end points et are also formed at positions separated from each other by 90 degrees. ing. The screw groove 34 is formed in a spiral shape of about one round from the start point st to the end point et, but is not limited to this, and may be one round or less, such as about half a turn or about 3/4 turn. It may be formed in a spiral shape of one or more laps such as one and a half laps or two laps.

Further, the screw grooves 34 are independently formed as four equal-order grooves that gradually increase in radius in the clockwise direction (clockwise) from the inner diameter side to the outer diameter side of the flange portion 33. However, the number of screw grooves 34 is not limited to this, and the number of screw grooves 34 may be various, such as 2nd class, 3rd class, 6th class, and the like. In this case, the slinger 30 rotates counterclockwise (counterclockwise) as shown by an arrow in the figure, contrary to the screw groove 34.

However, the groove formed on the outer surface 33g of the flange portion 33 of the slinger 30 does not necessarily have to be the screw groove 34. For example, as shown in FIG. 4A, in the slinger 30s, the slinger 30s has a radial shape extending from the inner diameter side to the outer diameter side of the outer surface 33g of the flange portion 33, and is linear in a direction perpendicular to the axis of the slinger 30. It may be a radial groove 37 (37a to 37h) extending in. In this case, the lip tip portion 22p of the main lip 22 slides on the outer surface 33g of the flange portion 33 at, for example, the position POS1 near the center of the radial groove 37.

Similarly, as shown in FIG. 4B, in the slinger 30v, the outer surface 33g of the flange portion 33 extends from the inner diameter side to the outer diameter side, but is shown from the inner diameter side toward the outer diameter side. It may be an inclined groove 38 (38a to 38h) extending linearly so as to be inclined to the middle right side. In this case, the lip tip portion 22p of the main lip 22 slides with the outer surface 33g of the flange portion 33 at a position POS2 slightly closer to, for example, near the center of the inclined groove 38.

In this case, the radial groove 37 and the inclined groove 38 have a much shorter length from the start point st to the end point et than the threaded groove 34, and the lubricating oil G1 is shortened along the radial groove 37 and the inclined groove 38. It will be possible to shake off in time and return to the A side of the cabin. Further, since the radial groove 37 and the inclined groove 38 can form a larger number of grooves than the threaded groove 34, a larger amount of the lubricating oil G1 can be applied to the machine A side in a shorter time than the threaded groove 34. It becomes possible to return to.

As described above, since the main lip 22 is formed in an overall curved shape from the lip base end 22n toward the lip tip 22p, the lip tip 22p is designated on the outer surface 33g of the flange 33. It is possible to make the relative contact angle θ1 (FIGS. 2 and 6) with the outer surface 33 g when pressed by the flange to be smaller than the conventional contact angle θ0 (FIG. 5). ..

In this case, as the contact angle θ1 becomes smaller than the conventional contact angle θ0, the contact area between the lip tip portion 22p of the main lip 22 and the outer surface 33g of the flange portion 33 increases, so that it becomes easier to maintain the sealing property. .. In this case, the lip tip portion 22p of the main lip 22 is in surface contact with the portion in contact with the outer surface 33g of the flange portion 33, and is gently from the outer surface 33g from the lip tip portion 22p to the lip base end portion 22n. It is separated. Here, the contact angle θ1 is such that when the lip tip portion 22p of the main lip 22 is pressed against the outer surface 33g of the flange portion 33, the lip bending portion 22w of the main lip 22 is not bent. It is assumed that the flange portion 33 is in contact with the outer surface 33 g of the flange portion 33.

As described above, in the oil seal 1, the main lip 22 of the elastic body portion 21 in contact with the outer surface 33 g of the flange portion 33 of the slinger 30 is arranged on the A side in the machine to prevent the lubricating oil from seeping out, and the slinger is prevented. The dust strip 23 of the elastic body portion 21 in contact with the outer peripheral surface 31a of the cylindrical portion 31 of the 30 is arranged on the outside B side to prevent dust from entering and the lubricating oil from leaking to the outside B side. is doing.

By the way, in the hub seal generally used for the hub bearing, the side lip (corresponding to the main lip 22) of the elastic body portion that comes into contact with the flange portion of the slinger is arranged on the B side outside the machine to prevent dust from entering and at the same time. A radial lip (corresponding to dust strip 23) that comes into contact with the cylindrical portion of the slinger is arranged on the A side of the machine to prevent leakage of lubricating oil.

That is, the oil seal 1 of the present invention is different from the hub seal because the arrangement of the main lip 22 in contact with the slinger 30 is exactly the opposite and the role thereof is also opposite to that of the hub seal used for the hub bearing. It has a radically different sealing structure.

In the oil seal 1 having such a configuration, the axis x is centered by the main lip 22 of the elastic body portion 21, the dust strip 23, the outer peripheral surface 31a of the cylindrical portion 31 of the slinger 30, and the outer surface 33g of the flange portion 33. An annular closed space S (FIG. 6) is formed.

This space S stores the lubricating oil G1 (FIG. 6) that has exuded from the cabin A side into the space S along the gap between the outer surface 33 g of the flange portion 33 of the slinger 30 and the lip tip portion 22p of the main lip 22. It is a space to do. The lubricating oil G1 stored in the space S is suppressed from leaking to the outside B side due to the presence of the dust strip 23.

<Action and effect>
In the above configuration, in the oil seal 1 according to the first embodiment, the seal portion 10 is press-fitted into the inner peripheral surface 202a of the housing 202 and fixed, and the slinger 30 is press-fitted into the outer peripheral surface 201a of the crankshaft 201. It is attached by being fixed.

At this time, the dust strip 23 of the elastic body portion 21 in the seal portion 10 is brought into contact with the outer peripheral surface 31a of the cylindrical portion 31 of the slinger 30 with a predetermined flange, and the lip tip portion 22p of the main lip 22 of the elastic body portion 21 is brought into contact with the slinger 30. And 33 g of the outer surface of the flange portion 33 of the slinger 30 are brought into contact with each other with a predetermined shrinkage margin.

In the oil seal 1 composed of the seal portion 10 and the slinger 30 which are combined and attached as described above, the slinger 30 rotates counterclockwise as the crankshaft 201 rotates.

At this time, the oil seal 1 has the lubricating oil G1 exuded into the space S on the inner peripheral side due to the influence of the four screw grooves 34 formed in the end region on the outer peripheral side (arrow c direction) of the flange portion 33. It is moved from (arrow d direction) toward the outer peripheral side (arrow c direction), and is sucked into the machine A side through the gap between the outer surface 33 g of the flange portion 33 and the inner peripheral surface 22u of the lip tip portion 22p of the main lip 22. Can be discharged (screw action). That is, the screw groove 34 has an oil discharging action of sucking and discharging the lubricating oil G1 from the space S to the inside A side.

In the oil seal 1, the presence of the intermediate lip 24 of the elastic body portion 21 can catch the lubricating oil G1 that has exuded into the space S, thereby preventing the lubricating oil G1 from directly reaching the dust strip 23. However, the lubricating oil G1 that has entered the space S can be sucked out to the cabin A side.

Further, the oil seal 1 moves the lubricating oil G1 in the space S from the inner peripheral side (arrow d direction) to the outer peripheral side (arrow c direction) by the centrifugal force accompanying the rotation of the flange portion 33 of the slinger 30. Lubricating oil G1 can be discharged from the gap between the outer surface 33g of the flange portion 33 and the inner peripheral surface 22u of the lip tip portion 22p of the main lip 22 toward the machine A side while shaking off (shaking action).

That is, the oil seal 1 is lubricated in the space S by the screwing action of the space S on the lubricating oil G1 due to the influence of the screw groove 34 and the shaking action of the space S on the lubricating oil G1 by the centrifugal force of the flange portion 33. The pumping effect of sucking the oil G1 into the cabin A and discharging it can be exerted.

By the way, as shown in FIG. 5, the conventional sealing device 100 (FIG. 8) has a relative contact angle θ0 between the inner surface 111u, which is the inner surface of the main lip 111, and the outer surface 103a of the flange portion 103. Compared to this, as shown in FIG. 6, in the oil seal 1 of the present invention, the relative contact angle θ1 between the inner peripheral surface 22u of the lip tip portion 22p of the main lip 22 and the outer surface 33g of the flange portion 33 Is smaller than the contact angle θ0 (θ0> θ1).

In the conventional sealing device 100, since the contact angle θ0 between the main lip 111 and the flange portion 103 is large, lubrication adhered between the inner side surface 111u of the main lip 111 and the outer surface 103a of the flange portion 103 by surface tension. The amount of oil G0 is small. Therefore, even if the pumping effect works, all the lubricating oil G0 that has entered the space S is not efficiently discharged to the A side in the machine, so that a part of the lubricating oil G0 remains.

On the other hand, in the oil seal 1 of the present invention, since the lip tip portion 22p is gently separated from the outer surface 33g of the flange portion 33 from the lip base end portion 22n to the inside of the lip tip portion 22p of the main lip 22. The relative contact angle θ1 between the peripheral surface 22u and the outer surface 33g of the flange portion 33 is smaller than the conventional contact angle θ0. Therefore, the amount of lubricating oil G1 that adheres and is stored between the inner peripheral surface 22u of the lip tip portion 22p of the main lip 22 and the outer surface 33g of the flange portion 33 due to surface tension is larger than before.

That is, the adhesion area of the lubricating oil G1 adhering to the inner peripheral surface 22u of the lip tip portion 22p of the main lip 22 and the outer surface 33g of the flange portion 33 is larger than before. Specifically, the adhesion width W1 of the lubricating oil G1 adhered to the inner peripheral surface 22u of the lip tip portion 22p of the main lip 22 and the outer surface 33g of the flange portion 33 is larger than that of the conventional sealing device 100 (FIG. 5). ..

Therefore, the lubricating oil G1 adhering due to surface tension between the inner peripheral surface 22u of the lip tip portion 22p of the main lip 22 and the outer surface 33g of the flange portion 33 is efficiently discharged to the inside A side by the pumping action as it is. Therefore, it is possible to prevent the lubricating oil G1 from remaining in the space S.

Thus, in the oil seal 1, even when the engine rotation speed becomes higher than the predetermined rotation speed, the lubricating oil G1 is shaken off by the centrifugal force of the flange portion 33 and the lubricating oil G1 is provided in the machine by the screw groove 34. The screwing action to return to the A side works effectively.

That is, in the oil seal 1, the pumping effect of efficiently returning the lubricating oil G1 exuded from the cabin A side to the space S from the space S to the cabin A side can be sufficiently exerted. Thus, even if the lubricating oil G1 in the machine A seeps into the space S, the oil seal 1 remains in the space S, and the leakage of the lubricating oil G1 from the space S to the outside B is greatly reduced. can do.

Further, in the oil seal 1, the main lip 22 is formed in a curved shape as a whole from the lip base end portion 22n to the lip tip portion 22p via the lip bending portion 22w, so that the amount of the main lip 22 is smaller than that of the conventional one. The relative contact angle θ1 between the lip tip portion 22p and the outer surface 33g of the flange portion 33 can be made smaller than the conventional contact angle θ0. As a result, the inner peripheral surface 22u of the lip tip portion 22p comes into close contact with the outer surface 33g of the flange portion 33 and closes the screw groove 34, so that static leakage is suppressed and the sliding resistance of the main lip 22 is also increased. It can be reduced.

<Second embodiment>
FIG. 7 is an enlarged cross-sectional view showing the configuration of a single unit of the oil seal 200 according to the second embodiment of the present invention. As shown in FIG. 7 in which the corresponding portions corresponding to those in FIG. 2 are designated by the same reference numerals, the oil seal 200 includes a seal portion 220 and a slinger 30 mounted on the outer peripheral surface 201a of the crankshaft 201, and these are combined. It is composed of.

That is, the oil seal 200 has a seal portion 220 instead of the seal portion 10, and the seal portion 220 includes a reinforcing ring 20 and an elastic body portion 221 integrally formed with the reinforcing ring 20. In this case, the main lip 232 of the elastic body portion 221 is used instead of the main lip 22 of the elastic body portion 21 in the first embodiment.

The main lip 232 has a lip arm portion 232r extending inward (arrow b direction) from the lip waist portion 221e and an outer peripheral side (arrow c direction) from the tip of the inside (arrow b direction) of the lip arm portion 232r. It is provided with a lip standing portion 232t extending inward (in the direction of arrow b) with a slight inclination. That is, in FIG. 7, the main lip 232 is formed in a substantially inverted L-shape in cross section as a whole.

The lip arm portion 232r of the main lip 232 is a cylindrical portion extending from the lip waist portion 221e with a certain thickness, and has an inner peripheral surface 232ru which is a surface on the inner peripheral side (arrow d direction) and an outer peripheral side (arrow c direction). It is defined by the outer peripheral surface 232 rg, which is the surface of the above. However, the present invention is not limited to this, and may extend from the lip waist portion 221e while becoming thinner, or may extend with an uneven thickness. It can be said that the lip arm portion 232r is a lip base end portion corresponding to a root portion protruding inward (in the direction of arrow b) from the lip waist portion 221e.

The lip standing portion 232t of the main lip 232 is a flange-shaped portion extending from the tip of the inside (arrow b direction) of the lip arm portion 232r toward the outer peripheral side (arrow c direction), and has an outer surface 232tout, an inner side surface 232tin, and an inner side surface 232tin. It is defined by the tip surface 232ttip. The inner side surface 232 tin of the lip standing portion 232 t is a contact surface that comes into contact with the outer surface 33 g of the flange portion 33. The outer surface 232tout of the lip standing portion 232t is a non-contact surface that does not come into contact with the outer surface 33g of the flange portion 33. The outer surface 232tout is not limited to the outer surface 33g of the flange portion 33, and does not come into contact with any portion.

The lip erecting portion 232t has a lip tip portion 232tp in which the width, that is, the thickness between the outer surface 232tout and the inner side surface 232tin is constant and is in close contact with the outer surface 33g of the flange portion 33. However, not limited to this, the outer surface 232tout is not substantially parallel to the inner surface 232ttin, and is a flat surface inclined so that the width with the inner surface 232ttip gradually narrows toward the tip surface 232ttip of the lip tip portion 232tp. It may be a flat surface in which the inner side surface 232 tin is inclined so that the width with the outer surface 232 ton is gradually narrowed toward the tip surface 232 tin.

The lip standing portion 232t extends slightly inclined inward (arrow c direction) and inward (arrow b direction) from the tip end side of the lip arm portion 232r approaching the outer surface 33g of the flange portion 33. Therefore, when the lip tip portion 232 tp is pressed against the outer surface 33 g of the flange portion 33, the relative contact angle θ1 with the outer surface 33 g is made smaller than the conventional contact angle θ0 (FIG. 5). It is possible.

Also in this case, as the contact angle θ1 becomes smaller than the conventional contact angle θ0, the contact area between the lip tip portion 232 tp of the lip standing portion 232 t of the main lip 232 and the outer surface 33 g of the flange portion 33 increases and is sealed. It becomes easier to maintain the sex. As a result, even in the second embodiment, the same action and effect as in the first embodiment can be obtained.

<Other embodiments>
Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the oil seals 1 and 200 according to the first and second embodiments described above, and the concept and the patent of the present invention are not limited to the above. Includes all aspects included in the claims. In addition, each configuration may be selectively combined as appropriate so as to achieve at least a part of the above-mentioned problems and effects. For example, the shape, material, arrangement, size, etc. of each component in the above embodiment can be appropriately changed depending on the specific usage mode of the present invention.

Further, although the oil seals 1 and 200 as the sealing device according to the present embodiment are used as a seal for an automobile engine, the application target of the sealing device according to the present invention is not limited to this. The present invention is applicable to all configurations that can utilize the effects of the present invention, such as other general-purpose machines and industrial machines.

1,100,200 ... Oil seal, 10,102,221 ... Seal part, 20 ... Reinforcing ring, 21,221 ... Elastic body part, 22,111,232 ... Main lip, 22p, 232p ... Lip tip part, 23 ... Dustrip, 24 ... Intermediate lip, 30 ... Slinger, 31 ... Cylindrical part, 31a ... Outer surface, 33, 103 ... Flange part, 33g ... Outer surface, 34, 104 ... Screw groove (groove), 37 ... Radial groove (groove) ), 38 ... Inclined groove (groove), 201 ... Crankshaft (rotating shaft), 202 ... Housing, S ... Space, A ... Inside the machine, B ... Outside the machine

Claims (2)

A cylindrical portion mounted on the outer peripheral surface of the rotating shaft that rotates with respect to the housing, and an annular flange portion extending from the inner end of the housing in the cylindrical portion in a direction perpendicular to the axis of the rotating shaft. With a slinger,
A sealing portion mounted on the housing and having a main lip that seals lubricating oil to the inside of the housing by slidably contacting the flat outer surface of the flange portion of the slinger.
The flange portion has a groove on the outer surface thereof in a portion in contact with the main lip to exert a draining action of returning the lubricating oil to the inside of the machine during rotation.
The main lip has a smaller relative contact angle when the outer surface of the flange portion and the main lip come into contact with each other, and the contact area between the main lip and the outer surface of the flange portion increases. In addition, it has a curved lip curved portion that is entirely curved from the lip base end portion of the main lip toward the lip tip portion that contacts the outer surface of the flange portion.
The contact angle is such that when the lip tip portion of the main lip is pressed against the outer surface of the flange portion, the lip curved portion of the main lip is not bent, and the flange portion is said to have a margin. A sealing device characterized by an angle of contact with the outer surface. The seal portion is
A dust strip that contacts the outer peripheral surface of the cylindrical portion of the slinger to prevent the lubricating oil from leaking to the outside of the machine of the housing and prevents dust from entering from the outside of the machine.
With an intermediate lip provided between the main lip and the dust strip,
The intermediate lip receives the lubricating oil that has entered from between the main lip and the outer surface of the flange portion, and prevents the lubricating oil from directly reaching the dust strip. The sealing device according to 1.

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