JP6890488B2 - 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. As this sealing device, a screw portion provided on the flange portion of the slinger exerts a pumping action when the crankshaft rotates to seal the lubricating oil in the machine (see, for example, Patent Document 1).

As shown in FIG. 9, such a sealing device 100 is mounted on the outer peripheral surface of the crankshaft 201 as a rotating shaft and is mounted on the slinger 101 that rotates together with the crankshaft 201 and 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 expands to the outer peripheral side after being bent from the outer peripheral side end of the bulging portion 103e to the outer peripheral B 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 of the flange portion 103 in the axial direction of the disk portion 103f, 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 screw 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 of 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 thread 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 crankshaft 201 The action of shaking off the lubricating oil from the space S to the inside of the machine A side by the centrifugal force of the above, and the action of returning the lubricating oil from the space S to the inside of the machine A side due to the influence of the screw groove 104 when the disk portion 103f of the flange portion 103 is rotating. (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 sealing device 100 described above, 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 into 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 of the present invention is to apply lubricating oil inside the machine to the flange portion of the slinger and the main lip even when the rotation speed of the rotating shaft is rotating 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 rotating with respect to the housing and the axis of the rotating shaft from the inner end of the cylindrical portion are perpendicular to the axis of the rotating shaft. The slinger having an annular flange portion extending in the above direction and the slinger mounted on the housing and slidably contacting the flat outer surface of the flange portion of the slinger seals the lubricating oil to the inside of the housing. A seal portion having a main lip is provided, and a groove is formed in a portion of the outer surface of the flange portion that comes into contact with the main lip to exert a draining action of returning the lubricating oil to the inside of the housing during rotation. The flange portion extending in a direction perpendicular to the axis is directed toward the inside so that the relative contact angle when the outer surface of the flange portion and the main lip come into contact with each other becomes smaller. It is characterized by being inclined.

In the present invention, the flange portion includes a vertical flange portion extending vertically from the inner end portion of the cylindrical portion in the outer peripheral direction, and an inclined flange portion inclined from the outer peripheral side end portion of the vertical flange portion. It is characterized by.

In the present invention, the flange portion is an L-shaped flange portion that is bent in an L shape from the inner end portion of the cylindrical portion, and includes a short portion and a longitudinal portion, and the contact angle becomes small. It is characterized in that it comes into contact with the main lip on the outer surface of the longitudinal portion so as to be inclined.

According to the present invention, even when the rotation speed of the rotating shaft is higher than a predetermined speed, 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 this.

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 lubricating oil according to the contact angle between the conventional main lip and the flange part of a slinger. FIG. 5 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. It is a graph which shows the relationship between the contact angle between the oil seal and a slinger which concerns on 1st Embodiment of this invention, and the air suction amount of the air containing lubricating oil. 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 device (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. This is to prevent the lubricating oil of A from leaking to the outside B and to prevent foreign matter such as dust from entering the inside A from the outside B.

The oil seal 1 is attached to the seal portion 10 mounted on the inner peripheral surface 202a, which is 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 (arrow c direction) of the crankshaft 201 as a rotating shaft that rotates with respect to the crankshaft 201, is provided, and these are combined to form a slinger 30.

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 mold, 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 inwardly with respect to 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 outer side (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 reinforcing ring 20.

The elastic body portion 21 covers the lip covering portion 21a that covers a part of the outer peripheral side (direction of arrow c) 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 (direction of arrow a). 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 on the inner peripheral side (arrow d direction) of the inner peripheral side disk portion 20d of the reinforcing ring 20, and is a portion located near the end portion of the reinforcing ring 20, the main lip 22, the dust strip 23, and , 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 (arrow b direction) end of the lip waist 21e toward the inner side (arrow b direction) and the outer peripheral side (arrow c direction). This is an annular lip portion, and the diameter increases from the inner peripheral side (arrow d direction) to the outer peripheral side (arrow c direction).

The main lip 22 is formed so that the thickness of the base portion 22r extending from the inner end (direction of arrow b) of the lip waist portion 21e is thinner than the thickness of the main body portion 22b. This is because, in the elastic body portion 21, the main lip 22 is easily bent from the root starting from the root portion 22r. This type of main lip 22 may be referred to as a thin-walled lip in the present specification.

The dust strip 23 of the elastic body portion 21 extends diagonally from the end 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 increases from the outer peripheral side (arrow c direction) to the inner peripheral side (arrow d direction). 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 while 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 attached by press-fitting and fixing it to the outer peripheral surface 201a of the crankshaft 201 that rotates 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 includes a vertical flange portion 34 and an inclined flange portion 35. The vertical flange portion 34 has a hollow disk shape centered on the axis x, which extends from the inner end (arrow b direction) of the cylindrical portion 31 toward the outer peripheral side (arrow c direction) in the radial direction perpendicular to the axis x. Is the part of.

The height of the vertical flange portion 34 toward the outer circumference side (direction of arrow c) is higher than the position of the lip tip of the intermediate lip 24, and the vertical flange portion 34 and the lip tip of the intermediate lip 24 are arranged so as to face each other. ing. The vertical flange portion 34 of the flange portion 33 has a narrower distance from the intermediate lip 24 because the bulging portion 103e of the flange portion 103 in the conventional slinger 101 does not exist.

The inclined flange portion 35 is a hollow disk-shaped portion inclined at a predetermined angle from the end portion of the vertical flange portion 34 on the outer peripheral side (arrow c direction) toward the inside (arrow b direction) and the outer peripheral side (arrow c direction). It is formed integrally with the vertical flange portion 34.

The inclined flange portion 35 has an outer surface 35a which is a flat surface on the outer side (direction of arrow a). In the end region on the outer peripheral side (direction of arrow c) of the outer side surface 35a, four spiral groove-shaped screw grooves used for discharging the lubricating oil G1 (FIG. 6) that has entered the space S to the outside A. 36 is provided.

As shown in FIG. 3, these four screw grooves 36 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 36 is formed in a spiral shape for 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 36 are independently formed as quaternary grooves that gradually increase the radius in the clockwise direction (clockwise) from the inner diameter side to the outer diameter side of the inclined flange portion 35. .. However, the number of screw grooves 36 is not limited to this, and the number of screw grooves 36 may be various such as 2nd grade, 3rd grade, 6th grade 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 36.

However, the groove formed in the inclined flange portion 35 of the flange portion 33 of the slinger 30 does not necessarily have to be the screw groove 36. For example, as shown in FIG. 4A, in the slinger 30S, the slinger portion 33 has a radial shape extending from the inner diameter side to the outer diameter side of the inclined flange portion 35 of the flange portion 33, and is in a direction perpendicular to the axis of the slinger 30. It may be a radial groove 37 (37a to 37h) extending linearly. In this case, the lip tip of the main lip 22 slides on the outer surface 35a of the inclined flange portion 35 at, for example, the position POS1 substantially near the center of the radial groove 37.

Similarly, as shown in FIG. 4B, in the slinger 30V, the inclined flange portion 35 of the flange portion 33 extends from the inner diameter side toward the outer diameter side, but extends from the inner diameter side toward the outer 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 right side in the drawing. In this case, the lip tip of the main lip 22 slides with the outer surface 35a of the inclined flange portion 35 at the position POS2 slightly closer to the outer periphery than, for example, substantially 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 screw groove 36, 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 screw groove 36, a larger amount of lubricating oil G1 can be applied to the machine A side in a shorter time than the screw groove 36. It becomes possible to return to.

The inclined flange portion 35 has a conventional inclined flange portion 35 having a relative contact angle θ1 (FIGS. 2 and 6) when the lip tip of the main lip 22 of the elastic body portion 21 and the outer surface 35a come into contact with each other. The flange portion 103 is inclined to a predetermined angle for the purpose of making it smaller than the contact angle θ0 (FIG. 5) of the flange portion 103.

In this case, since the contact angle θ1 is smaller than the conventional contact angle θ0, the contact area between the lip tip of the main lip 22 and the outer surface 35a is increased, so that the sealing property can be easily maintained. Here, the contact angle θ1 is such that the lip tip of the main lip 22 is pressed against the outer surface 35a of the inclined flange portion 35, but the lip tip side of the main lip 22 is not bent. It is assumed that the outer surface 35a of the 35 is in contact with the outer surface 35a. However, the present invention is not limited to this, and the outer surface 35a of the inclined flange portion 35 and the tip of the lip may be in contact with each other with a allowance such that the tip end side of the main lip 22 is bent. In this case, it is assumed that the contact angle θ1 measured at the position on the tip side of the length from the lip tip to the base of the main lip 22 is shorter than the length of about 20% from the lip tip.

As described above, in the oil seal 1, the main lip 22 of the elastic body portion 21 in contact with the outer surface 35a of the inclined flange portion 35 in the flange portion 33 of the slinger 30 is arranged on the A side in the machine, and the lubricating oil exudes. In addition to preventing this, 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 slinger 30 is arranged on the outside B side to prevent dust from entering and the lubricating oil from leaking to the outside B side. It has a structure to prevent it.

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 in 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 opposite and the role thereof is also opposite to that of the hub seal used for the hub bearing. It has a fundamentally different sealing structure.

In the oil seal 1 having such a configuration, 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 vertical flange portion 34 and the inclined flange portion of the flange portion 33. An annular closed space S (FIG. 6) centered on the axis x is formed by 35.

This space S is the lubricating oil G1 that has exuded into the space S from the inside of the machine A side along the gap between the outer surface 35a of the inclined flange portion 35 in the flange portion 33 of the slinger 30 and the lip tip of the main lip 22 (FIG. 6). ) Is a storage space. 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 to be 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 shrinkage, and the main lip 22 of the elastic body portion 21 is brought into contact with the flange of the slinger 30. The outer surface 35a of the inclined flange portion 35 of the portion 33 is brought into contact with the outer surface 35a with a predetermined tightening margin. In this case, since the thickness of the base portion 22r of the main lip 22 is thinner than that of the main body portion 22b, even if the main lip 22 bends from the base, the lip tip does not bend.

At this time, the lip tip of the main lip 22 of the elastic body portion 21 is combined with the seal portion 10 and the slinger 30 so that any one of the four screw grooves 36 and the lip tip of the main lip 22 always come into contact with each other.

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 36 formed in the end region on the outer peripheral side (direction of arrow c) 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 35a of the inclined flange portion 35 of the flange portion 33 and the lip tip of the main lip 22 and discharged. (Screw action) is possible. That is, the screw groove 36 has a function of sucking and discharging the lubricating oil G1 from the space S to the inside A side of the machine.

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, thus 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 35a of the inclined flange portion 35 of the flange portion 33 and the lip tip of the main lip 22 toward the inside A side while shaking off (shaking off action).

That is, the oil seal 1 has a space due to the screwing action of the space S on the lubricating oil G1 due to the influence of the screw groove 36 and the shaking action of the space S on the lubricating oil G1 by the centrifugal force of the inclined flange portion 35 of the flange portion 33. The pumping effect of sucking the lubricating oil G1 existing in S into the machine A and discharging it can be exerted.

By the way, as shown in FIG. 5, the conventional sealing device 100 (FIG. 9) 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. In comparison, as shown in FIG. 6, in the oil seal 1 of the present invention, the relative contact angle θ1 between the inner surface 22u of the main lip 22 and the outer surface 35a of the inclined flange portion 35 is larger than the contact angle θ0. Is also smaller (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, the relative contact angle θ1 between the main lip 22 and the inclined flange portion 35 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 side surface 22u of the main lip 22 and the outer surface 35a of the inclined flange portion 35 due to surface tension is larger than before.

That is, the adhesion area of the lubricating oil G1 adhering to the inner side surface 22u of the main lip 22 and the outer surface 35a of the inclined flange portion 35 is larger than that of the conventional one. Specifically, the adhesion width W1 of the lubricating oil G1 adhering to the inner side surface 22u of the main lip 22 and the outer surface 35a of the inclined flange portion 35 is larger than that of the conventional sealing device 100 (FIG. 5).

For this reason, all the lubricating oil G1 adhering due to surface tension between the inner side surface 22u of the main lip 22 and the outer surface 35a of the inclined flange portion 35 is efficiently discharged to the inside A side by the pumping action as it is, so that space is provided. It is possible to prevent the lubricating oil G1 from remaining in S.

By the way, in the conventional flange portion 103, the velocity vector toward the outer peripheral side (direction of arrow c) when the lubricating oil G0 adhering to the outer surface 103a of the flange portion 103 is shaken off by centrifugal force is large.

On the other hand, in the oil seal 1 of the present invention, since the inclined flange portion 35 is inclined, the outer peripheral side when the lubricating oil G1 adhering to the outer surface 35a of the inclined flange portion 35 is shaken off by centrifugal force. The velocity vector toward (arrow c direction) becomes smaller than that of the conventional flange portion 103.

Further, in the oil seal 1, since the inclined flange portion 35 is inclined, the lubricating oil G1 adhering to the outer surface 35a of the inclined flange portion 35 is more adhering to the conventional flange portion 103 than the lubricating oil G0. It is in a state where it is harder to separate than. Therefore, in the oil seal 1, since the inclined flange portion 35 is inclined, the lubricating oil G1 adhering to the inclined flange portion 35 is inside the machine along the outer surface 35a of the inclined flange portion 35 due to centrifugal force and surface tension. Efficiently discharged to the A side.

Thus, in the oil seal 1, even when the engine speed becomes higher than the predetermined 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 36. 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 space S to the space S from the space S to the machine A side in a short time can be sufficiently exhibited. Thus, in the oil seal 1, even if the lubricating oil G1 in the machine A seeps into the space S, it 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 distance between the vertical flange portion 34 of the slinger 30 and the intermediate lip 24 is narrower than that of the conventional sealing device 100 (FIG. 10). It is possible to prevent dust from entering more effectively than before.

Further, in the oil seal 1, since the relative contact angle θ1 between the lip tip of the main lip 22 and the outer surface 35a of the inclined flange portion 35 is smaller than before, the inner side surface 22u of the main lip 22 and the inclined flange portion 35 Since the degree of adhesion to the outer side surface 35a is increased as compared with the conventional case and many screw grooves 36 are closed, static leakage can be suppressed as compared with the conventional case.

<Example>
In the oil seal 1 of the present invention, when the engine speed is, for example, 8000 rpm, the relative contact angle θ1 when the main lip 22 and the inclined flange portion 35 of the flange portion 33 come into contact is about 30 degrees. When the angle was gradually reduced from a large angle to a small angle of about 0 degrees, the change in the amount of air sucked into the machine A side of the air containing the lubricating oil G1 existing in the space S was measured. FIG. 7 is a graph showing the relationship between the contact angle θ1 and the air suction amount.

Here, as the main lip 22 used for the slinger 30 of the oil seal 1, not only the thin-walled lip as described above, but also the thickness of the base portion 22r is substantially the same as or greater than the thickness of the main body portion 22b. It may be a thick lip having a thick lip, and in the following description, the thin lip 220n and the thick lip 220k are distinguished. As a comparison target, the thin-walled lip used for the slinger (slinger having a shape corresponding to the slinger 30 of the present invention) in which the thread groove 36 is not formed is distinguished as the thin-walled lip 220x.

According to this measurement result, when the contact angle θ1 is large, the air suction amount is 0 [ml / min] in any of the thin-walled lip 220n, the thick-walled lip 220k, and the thin-walled lip 220x, but the contact angle θ1 becomes smaller. It is shown that the amount of air suction increases almost linearly. Regarding the thin-walled lip 220x in which the screw groove 36 is not formed, the air suction amount is 0 [ml / min] even if the contact angle θ1 becomes small because the screw groove 36 is not provided, and the space S is lubricated. It is predicted that the oil G1 is likely to seep out.

As described above, in the oil seal 1, when the engine speed is 8000 rpm, the relative contact angle θ1 between the main lip 22 and the inclined flange portion 35 of the flange portion 33 becomes small, and the inclined flange of the lubricating oil G1 becomes small. It was found that when the adhesion width W1 to the outer surface 35a of the portion 35 is increased, the amount of air sucked into the machine A side of the air containing the lubricating oil G1 existing in the space S is significantly increased.

That is, the oil seal 1 has a relative contact angle between the main lip 22 and the inclined flange portion 35 of the flange portion 33 even when the rotation speed of the crankshaft 201 is higher than a predetermined value as compared with the conventional case. It has been found that when θ1 becomes smaller, the lubricating oil G1 that has exuded from the cabin A side into the space S can be efficiently returned to the cabin A side, and the lubricating oil G1 can be prevented from being stored in the space S.

<Second embodiment>
FIG. 8 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. 8 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 10 and a slinger 230 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 is characterized in that the slinger 230 is used instead of the slinger 30 of the oil seal 1 in the first embodiment.

The slinger 230 includes a cylindrical portion 231 and a curved portion 232, and an L-shaped flange portion 233. The cylindrical portion 231 has the same configuration as the cylindrical portion 31 in the first embodiment, but is formed longer than the cylindrical portion 31 inward (in the direction of arrow b) in the axis x direction. The curved portion 232 is an annular portion centered on the axis x that is curved like a U shape from the inner end (direction of arrow b) of the cylindrical portion 231.

The L-shaped flange portion 233 is formed in an L-shape as a whole, and is an annular portion centered on the axis x, which is integrally connected to the end portion of the curved portion 232 on the outer peripheral side (direction of arrow c). .. The L-shaped flange portion 233 has an integral configuration including a short portion 234 and a longitudinal portion 235, and has an inner end (arrow b direction) of the short portion 234 and an outer peripheral side (arrow) of the curved portion 232. The end in the c direction) is connected. The longitudinal portion 235 of the L-shaped flange portion 233 has an outer surface 235a which is an outer surface (direction of arrow a), and a screw groove 36 is formed on the outer surface 235a.

The longitudinal portion 235 of the L-shaped flange portion 233 has a relative contact angle θ1 between the lip tip of the main lip 22 of the elastic body portion 21 and the outer surface 235a as compared with the conventional case as in the first embodiment. I'm making it smaller.

In the oil seal 200 having such a configuration, the same effect as that of the first embodiment can be obtained. Specifically, in the oil seal 200, the shearing action of the lubricating oil G1 due to the centrifugal force of the longitudinal portion 235 of the L-shaped flange portion 233 and the screwing action of returning the lubricating oil G1 to the A side in the machine by the screw groove 36 are performed. It works effectively and can fully exert the pumping effect. That is, the oil seal 200 efficiently returns the lubricating oil G1 that has exuded from the cabin A side into the space S to the cabin A side even when the engine is rotating at high speed, and the lubricating oil G1 is stored in the space S. Since it can be prevented, it is possible to significantly reduce the leakage of the lubricating oil G1 in the machine A to the outside B through the space S.

Further, in the oil seal 200, since the cylindrical portion 231 of the slinger 230 is longer in the axis x direction than the cylindrical portion 31 of the first embodiment, the fitting area of the crankshaft 201 with the outer peripheral surface 201a becomes large. The misalignment of the slinger 230 in the x-axis direction can be suppressed by that amount.

<Other embodiments>
In the first and second embodiments described above, the case where a thin-walled lip having a thickness of the base portion 22r thinner than the thickness of the main body portion 22b is used as the main lip 22 has been described. The present invention is not limited to this, and the thickness of the base portion 22r may be equal to or thicker than the thickness of the main body portion 22b.

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. 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.

1,200 ... oil seal, 10,102 ... seal part, 20 ... reinforcing ring, 21 ... elastic body part, 22,111 ... main lip, 23 ... dust strip, 24 ... intermediate lip, 30,101,230 ... slinger, 31, 231 ... Cylindrical part, 31a ... Outer surface, 33, 103 ... Flange part, 34 ... Vertical flange part, 35 ... Inclined flange part, 35a, 235a ... Outer surface, 36 ... Screw groove (groove), 37 ... Radial groove (Groove), 38 ... Inclined groove (groove), 201 ... Crankshaft (rotating shaft), 202 ... Housing, 232 ... Curved part, 233 ... L-shaped flange part, 234 ... Short part, 235 ... Longitudinal part, S ... space, A ... in-flight, B ... out-of-flight

Claims (3)

A cylindrical portion mounted on the outer peripheral surface of a 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 that has
A sealing portion that is mounted on the housing and has 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.
A groove is formed on the outer surface of the flange 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, and the outside of the flange portion. It extends in a direction perpendicular to the axis so that the relative contact angle when the side surface and the main lip come into contact with each other becomes smaller and the contact area between the main lip and the outer surface of the flange portion increases. sealing device, wherein the flange portion to the line is inclined toward the outer circumferential side away from the inboard side and the axis of the housing. The flange portion is formed from a vertical flange portion extending perpendicularly to the axis in the outer peripheral direction away from the axis from the inner end of the housing in the cylindrical portion, and from the outer peripheral end of the vertical flange portion. The sealing device according to claim 1, further comprising an inclined flange portion inclined toward the inside of the housing and the outer peripheral side away from the axis with respect to a line extending in a direction perpendicular to the axis. The flange portion is an L-shaped flange portion that is bent in an L shape from the inner end of the housing in the cylindrical portion via a curved portion that is curved in a U shape, and is on the outer side of the housing and on the outside of the machine. It is provided with a short portion extending toward the outer peripheral side away from the axis and a longitudinal portion extending from the outer peripheral side end portion of the short portion toward the inside and the outer peripheral side of the housing so that the contact angle becomes small. The sealing device according to claim 1, wherein the sealing device comes into contact with the main lip on the outer surface of the longitudinal portion inclined to.

Images