JP2021008944A - Sealing device - Google Patents

Abstract

To provide a sealing device capable of maintaining sealing performance over a long time.SOLUTION: A sealing device 1 includes: a main seal part 2 attached to a shaft hole; a dust seal part 3 fitted in the main seal part 2; and a slinger 4 attached to a shaft. The main seal part 2 has: a reinforcement ring 10; and an annular elastic body part 20 attached to the reinforcement ring 10. The elastic body part 20 has an annular main lip 21 which contacts with the slinger 4 from the outer periphery side. The slinger 4 has an annular flange part 41 extending to the outer periphery side. The dust seal part 3 is located at the outer side of the main lip 21 and has: an annular side lip 31 which contacts with the flange part 41 from the inner side; and a sealing ring 32 which contacts with the slinger 4 from the outer periphery side and is formed by an annular resin.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sealing device for sealing between a shaft and a hole into which the shaft is inserted, and more particularly to a sealing device used under conditions of use that are expected to be exposed to muddy water, dust, and the like.

For example, in agricultural machinery such as tractors and cultivators and construction machinery, a sealing device has been conventionally used to seal an annular space between an axle and a shaft hole into which the axle is inserted. Due to the usage environment of agricultural machines such as tractors and cultivators and construction machines, it is assumed that the sealing devices used in these machines will be exposed to foreign substances such as muddy water and dust, and foreign substances such as muddy water and dust will be exposed. There is a demand for foreign matter blocking performance that prevents foreign matter from entering the seal lip side. For this reason, some conventional sealing devices used in agricultural machinery such as tractors and cultivators and construction machinery aim to improve the blocking performance against foreign substances. Some of such conventional sealing devices aim to improve the blocking performance of foreign matter by increasing the number of dust strips contained in the elastic body portion (see, for example, Patent Document 1).

JP-A-2017-219176

In the conventional sealing device as described above, since the elastic body portion has a plurality of dust strips, it is possible to improve the foreign matter blocking performance. However, there is still a demand for a sealing device capable of maintaining the foreign matter blocking performance even after a longer period of use. As described above, the conventional sealing device used for agricultural machinery and construction machinery is required to have a configuration capable of maintaining the blocking performance of foreign matter for a long period of time.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a sealing device capable of maintaining a foreign matter blocking performance for a long period of time.

In order to achieve the above object, the sealing device according to the present invention is a sealing device for sealing an annular gap between a shaft and a hole into which the shaft is inserted, and is a main sealing device attached to the hole. The main seal portion includes a seal portion, a dust seal portion fitted to the main seal portion, and a slinger attached to the shaft, and the main seal portion has an annular reinforcing ring around the axis and elasticity attached to the reinforcing ring. It has an annular elastic body portion formed from the body around the axis, and the elastic body portion has a main lip which is an annular lip around the axis that contacts the slinger from the outer peripheral side. The slinger has a flange portion that is an annular portion around the axis extending toward the outer peripheral side, and the dust seal portion is located on one side of the main lip in the axial direction. The dust seal portion includes a side lip that is an annular lip around the axis that contacts the flange portion from the other side in the axial direction, and a resin that is annular around the axis that contacts the slinger from the outer peripheral side. It is characterized by having a seal ring formed from.

In the sealing device according to one aspect of the present invention, the outer peripheral edge of the flange portion faces the main seal portion from the inner peripheral side via an annular gap, and the gap forms a labyrinth seal. ing.

In the sealing device according to one aspect of the present invention, the dust seal portion has a backup ring which is an annular member around the axis that pushes the seal ring to the inner peripheral side.

In the sealing device according to one aspect of the present invention, the dust seal portion has a mounting ring which is an annular member around the axis, and the side lip is mounted on the mounting ring, and the reinforcing ring and the reinforcing ring The mounting ring has portions facing each other in the axial direction, the backup ring is provided between the reinforcing ring and the facing portions of the mounting ring, and the mounting ring is provided. It has a tubular portion that is a tubular portion extending along the axis, and an opposing portion that is an annular portion that is a portion facing the reinforcing ring that extends from the tubular portion toward the inner peripheral side. The dust seal portion can be fitted to the main seal portion via the tubular portion of the mounting ring, and the backup ring comes into contact with the tubular portion of the mounting ring from the inner peripheral side.

In the sealing device according to one aspect of the present invention, an elastic member is attached to the inner peripheral surface of the slinger.

According to the sealing device according to the present invention, it is possible to maintain the blocking performance of foreign matter for a long period of time.

It is sectional drawing which shows the schematic structure of the sealing device which concerns on embodiment of this invention in the cross section along the axis. FIG. 5 is a partially enlarged cross-sectional view showing an enlarged part of a cross section along an axis to show a schematic configuration of the sealing device shown in FIG. 1. FIG. 5 is a partially enlarged cross-sectional view of the sealing device in a used state in which the sealing device shown in FIG. 1 is attached to an attachment target.

Hereinafter, the sealing device according to the embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view taken along the axis x for showing a schematic configuration of the sealing device 1 according to the embodiment of the present invention, and FIG. 2 is a partially enlarged cross-sectional view of the sealing device 1 shown in FIG. Is. The sealing device 1 according to the present embodiment is a sealing device for sealing an annular gap between a shaft and a hole into which the shaft is inserted, and is particularly exposed to foreign matter such as muddy water and dust. It is a sealing device used under the expected usage conditions. The sealing device 1 is used, for example, in agricultural machinery such as a tractor or a cultivator, or a construction machine to seal an annular space between an axle and a shaft hole. The object to which the sealing device 1 according to the embodiment of the present invention is applied is not limited to the above.

Hereinafter, for convenience of explanation, the side in the direction of the arrow a (see FIG. 1) is defined as the inside (the other side) in the axis x direction, and the side in the direction of the arrow b (see FIG. 1) is defined as the outside (one side) in the axis x direction. .. More specifically, the inside is the side of the space to be sealed (the side of the object to be sealed), the side of the space where the object to be sealed such as lubricating oil exists, and the outside is the side opposite to the inside. , On the atmospheric side. Further, in the direction orthogonal 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 approaches the axis x (arrow d in FIG. 1). Direction) is the inner circumference side.

The sealing device 1 according to the present embodiment is attached to a main seal portion 2 attached to a shaft hole to be attached to be described later, a dust seal portion 3 to be fitted to the main seal portion 2, and a shaft to be attached to be described later. It is equipped with a slinger 4 that can be used. The main seal portion 2 has an annular reinforcing ring 10 around the axis x and an annular elastic body portion 20 around the axis x formed from the elastic body attached to the reinforcing ring 10. The elastic body portion 20 has a main lip 21 which is an annular lip around an axis x that contacts the slinger 4 from the outer peripheral side. The slinger 4 has a flange portion 41 which is an annular portion around an axis x extending toward the outer peripheral side (side in the direction of arrow c). The dust seal portion 3 is located on one side (arrow b direction side, outside) of the main lip 21 in the axis x direction, and the dust seal portion 3 is located on the flange portion 41 on the other side (arrow a) in the axis x direction. It has a side lip 31 which is an annular lip around the axis x which comes into contact with the slinger 4 from the outer peripheral side, and a seal ring 32 formed of an annular resin around the axis x which comes into contact with the slinger 4 from the outer peripheral side. .. Hereinafter, the structure of the sealing device 1 will be specifically described.

As shown in FIGS. 1 and 2, the reinforcing ring 10 in the main seal portion 2 is an annular metal member centered on or substantially centered on the axis x, and the main seal portion 2 is press-fitted into the shaft hole of the housing described later. It is formed so that it can be fitted, fitted and attached. The reinforcing ring 10 has a facing portion 11 which is a portion facing the mounting ring 34 described later in the dust seal portion 3 in the axis x direction.

As shown in FIG. 1, the reinforcing ring 10 has, for example, a tubular portion 12 which is a tubular portion extending along an axis x located on the outer peripheral side, and an inner peripheral side and an outer side from an inner end portion of the tubular portion 12. It has a folded-back portion 13 which is a portion extending to. The facing portion 11 extends from the end portion on the inner peripheral side of the folded-back portion 13 to the inner peripheral side. More specifically, the tubular portion 12 of the reinforcing ring 10 is a cylindrical or substantially cylindrical portion having an axis x as a central axis. More specifically, the folded-back portion 13 has a curved portion 13a that bends and extends from the inner end portion of the tubular portion 12 to the region on the inner peripheral side, and the folded portion 13a along the axis x from the inner peripheral side end portion of the curved portion 13a. It has a tubular portion 13b extending outward. The curved portion 13a is a portion that changes the extending direction of the reinforcing ring 10, and is a portion that changes the extending direction of the reinforcing ring 10 extending inward in the axis x direction in the tubular portion 12 so as to be outward in the axis x direction. is there. As shown in FIGS. 1 and 2, the curved portion 13a is formed so that the shape of the cross section along the axis x (hereinafter, also simply referred to as a cross section) is substantially U-shaped. The shape of the curved portion 13a may be another shape. Further, the tubular portion 13b of the folded portion 13 is, for example, a cylindrical or substantially cylindrical portion with the axis x as the central axis, as shown in FIGS. 1 and 2. The tubular portion 13b may extend linearly in cross section, or may be bent and extended. The shape of the tubular portion 13b may be another shape. As shown in FIGS. 1 and 2, the facing portion 11 is, for example, an annular or substantially annular plate-shaped portion extending in the radial direction about the axis x. The facing portion 11 may be inclined with respect to the radial direction. The facing portion 11 may extend linearly in a cross section, or may be bent and extended. In the reinforcing ring 10, the facing portion 11 is located in a region on the inner peripheral side of the tubular portion 12.

Further, as shown in FIG. 1, the reinforcing ring 10 has a labyrinth portion 14 extending from the outer end portion of the tubular portion 12 to the outer peripheral side and the outer side. The labyrinth portion 14 is a portion that forms a labyrinth seal together with the flange portion 41 of the slinger 4, as will be described later, and has a flange portion 14a that is an annular plate-shaped portion extending from the outer end portion of the tubular portion 12 to the outer peripheral side. It has a tubular portion 14b which is a tubular portion extending outward from an end portion on the outer peripheral side of the flange portion 14a. As shown in FIGS. 1 and 2, the flange portion 14a is, for example, an annular or substantially annular plate-shaped portion extending in the radial direction about the axis x. The flange portion 14a may be inclined with respect to the radial direction. The flange portion 14a may extend linearly or bend in cross section. As shown in FIGS. 1 and 2, the tubular portion 14b is, for example, a cylindrical or substantially cylindrical portion having an axis x as a central axis. The tubular portion 14b may extend linearly in cross section, or may be bent and extended. An elastic body portion 20 is attached to the reinforcing ring 10, and the elastic body portion 20 is reinforced.

As shown in FIGS. 1 and 2, the elastic body portion 20 is attached to the reinforcing ring 10 so as to cover the whole or a part of the reinforcing ring 10. The elastic body portion 20 has a main lip 21 as described above, and also has a gasket portion 22. Specifically, as shown in FIG. 2, the gasket portion 22 is a portion attached to the outer peripheral surface 12a, which is the outer peripheral surface of the tubular portion 12 of the reinforcing ring 10. The outer diameter of the gasket portion 22 is larger than the diameter of the inner peripheral surface of the shaft hole to which the sealing device 1 (main seal portion 2) is attached. Therefore, when the sealing device 1 is fitted into the shaft hole, the gasket portion 22 is compressed in the radial direction between the tubular portion 12 of the reinforcing ring 10 and the shaft hole, and the tubular portion of the shaft hole and the reinforcing ring 10 is compressed. Seal between 12 and 12. As a result, the space between the sealing device 1 and the shaft hole is sealed. The outer diameter of the gasket portion 22 does not have to be larger than the diameter of the inner peripheral surface of the shaft hole over the entire axis x direction, and the outer diameter of the gasket portion 22 is larger than the diameter of the inner peripheral surface of the shaft hole in some parts. It may be. For example, an annular convex portion whose tip diameter is larger than the diameter of the inner peripheral surface of the shaft hole may be formed on the outer peripheral surface of the gasket portion 22.

As shown in FIGS. 1 and 2, the main lip 21 extends in a tubular shape from the facing portion 11 on the inner peripheral side of the tubular portion 13b of the folded portion 13 of the reinforcing ring 10, and extends to the inner (tip side) portion. It has an annular lip tip 23. The lip tip portion 23 is a portion formed so as to come into contact with the tubular portion 42 of the slinger 4 described later with a predetermined tightening margin, and is, for example, a portion having a wedge-shaped cross-sectional shape that is convex toward the inner peripheral side. The main lip 21 may extend from the tubular portion 13b and the opposing portion 11 of the folded-back portion 13, or may extend from the tubular portion 13b of the folded-back portion 13.

Further, as shown in FIG. 2, an annular recess 24 is formed on the outer peripheral side of the main lip 21 at a position facing back to the lip tip 23, and a garter spring 25 is fitted in the recess 24. There is. The garter spring 25 pushes the lip tip 23 in the direction toward the axis x so that the lip tip 23 follows the displacement of the cylinder 42 of the slinger 4 due to the displacement of the shaft. Gives a predetermined amount of tension to the tubular portion 42 of the. As will be described later, the lip tip portion 23 comes into contact with the outer peripheral surface 42a of the tubular portion 42 of the slinger 4 to seal between the sealing device 1 (main lip portion 2) and the tubular portion 42 of the slinger 4.

As described above, the elastic body portion 20 has a portion that covers the main lip 21, the gasket portion 22, and the other reinforcing ring 10, and each portion is integrated, and the elastic body portion 20 is the same. It is integrally formed from the material.

The above-mentioned reinforcing ring 10 is formed of a metal material, and examples of the metal material include stainless steel and SPCC (cold rolled steel). Further, as the elastic body of the elastic body portion 20, 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 10 is manufactured by, for example, press working or forging, and the elastic body portion 20 is molded by cross-linking (vulcanization) molding using a molding die. At the time of this cross-linking molding, the reinforcing ring 10 is arranged in the molding die, the elastic body portion 20 is adhered to the reinforcing ring 10 by cross-linking adhesion, and the elastic body portion 20 and the reinforcing ring 10 are integrally molded. Will be done.

As described above, the dust seal portion 3 has a side lip 31 and a seal ring 32, and the dust seal portion 3 has a backup ring 33 and a mounting ring 34. As shown in FIG. 1, the backup ring 33 is an annular member around the axis x that pushes the seal ring 32 inward. As shown in FIG. 1, the mounting ring 34 is an annular member around the axis x, and a side lip 31 is attached to the mounting ring 34. The mounting ring 34 has a facing portion 35 which is a portion facing the facing portion 11 of the reinforcing ring 10 in the axial direction x direction, and the backup ring 33 has a facing portion 11 of the reinforcing ring 10 and a facing portion of the mounting ring 34. It is provided between 35.

Specifically, as shown in FIGS. 1 and 2, the mounting ring 34 has a tubular portion 34a which is a tubular portion extending along x along the axis and an opposing portion 35 extending from the tubular portion 34a toward the inner peripheral side. And have. As shown in FIGS. 1 and 2, the tubular portion 34a is, for example, a cylindrical or substantially cylindrical portion having an axis x as a central axis. The tubular portion 34a may extend in a straight line or may be bent in a cross section. As shown in FIGS. 1 and 2, the facing portion 35 is, for example, an annular plate-shaped portion extending in the radial direction about the axis x. The facing portion 35 may be inclined with respect to the radial direction. The facing portion 35 may extend linearly in a cross section, or may be bent and extended. In the mounting ring 34, the facing portion 35 extends from, for example, the outer end of the tubular portion 34a, and the cross-sectional shape of the mounting ring 34 is substantially L-shaped.

The mounting ring 34 can be fitted to the main lip portion 2 in the tubular portion 34a. Specifically, the tubular portion 34a is pressed against the main lip portion 2 toward the outer peripheral side at the portion of the tubular portion 12 of the reinforcing ring 10. As shown in FIGS. 1 and 2, the inner peripheral surface 12b of the reinforcing ring 10 facing the inner peripheral side of the tubular portion 12 is covered with the elastic body portion 20, and the tubular portion 34a is reinforced via the elastic body portion 20. It is pressed against the tubular portion 12 of the ring 10 from the inner peripheral side. The inner peripheral surface 12b of the cylindrical portion 12 of the reinforcing ring 10 is not covered by the elastic body portion 20, and the tubular portion 34a is directly pressed against the tubular portion 12 of the reinforcing ring 10 from the inner peripheral side without passing through the elastic body portion 20. You may be able to do it. Further, as will be described later, as shown in FIGS. 1 and 2, the outer peripheral surface 34b facing the outer peripheral side of the tubular portion 34a of the mounting ring 34 is covered with an elastic body forming the side lip 31, and the tubular portion 34a Is pressed against the main lip portion 2 from the outer peripheral side via this elastic body. Further, the outer peripheral surface 34b of the tubular portion 34a of the mounting ring 34 is not covered with the elastic body forming the side lip 31, and the tubular portion 34a is directly pressed against the main lip portion 2 from the outer peripheral side. May be good.

In the main seal portion 2 and the dust seal portion 3, for example, in a state where the mounting ring 34 is fitted to the main lip portion 2, the facing portions 35 of the mounting ring 34 are reinforced rings at predetermined intervals in the axis x direction. It faces the facing portion 11 of 10 from the outside. For example, the mounting ring 34 fitted to the main lip portion 2 comes into contact with the elastic body portion 20 or the facing portion 11 at the inner end of the tubular portion 34a, whereby the mounting ring 34 of the mounting ring 34 The distance between the reinforcing ring 10 of the facing portion 35 and the facing portion 11 in the axis x direction is determined.

The side lip 31 is formed of an elastic body and is attached to the mounting ring 34 as described above. As shown in FIG. 1, the front end surface 31a faces the inside of the flange portion 41 of the slinger 4. (Inner side surface 41a) is brought into contact with a predetermined tightening allowance.

Specifically, the side lip 31 is formed as a part of the side lip portion 30, and the side lip portion 30 has a mounting portion 30a which is a portion attached to the mounting ring 34. The mounting portion 30a is mounted so as to cover the outer peripheral surface 34b of the tubular portion 34a of the mounting ring 34 and the surface facing the outside of the facing portion 35 (outer surface 35a). The mounting portion 30a does not have to cover the outer peripheral surface 34b of the tubular portion 34a.

Further, the side lip 31 has a root portion 31b and a tip portion 31c. The root portion 31b is a portion extending from a portion of the mounting portion 30a that covers the outer surface 35a of the facing portion 35, and has, for example, a cross-sectional shape that is curved so as to be convex toward the inner peripheral side. The tip portion 31c extends outwardly from the root portion 31b so as to be inclined toward the outer peripheral side, and has, for example, a conical tubular shape whose diameter increases toward the outside in the axis x direction. A tip surface 31a is formed at the outer peripheral end of the tip 31c. The side lip 31 does not have a root portion 31b, and the tip portion 31c may extend from the mounting portion 30a.

As described above, the seal ring 32 is an annular member around the axis x. For example, the inner peripheral surface 32a having a cylindrical surface or a substantially cylindrical surface with the axis x as the central axis and the axis x as the central axis. It has an outer peripheral surface 32b having a cylindrical surface shape or a substantially cylindrical surface shape. The inner peripheral surface 32a is a surface facing the inner peripheral side of the seal ring 32, and the outer peripheral surface 32b is a surface facing the outer peripheral side of the seal ring 32. The inner peripheral surface 32a of the seal ring 32 comes into contact with the tubular portion 42 of the slinger 4. As described above, the seal ring 32 is formed of a resin material, and examples of the resin material of the seal ring 32 include PTFE (polytetrafluoroethylene) and the like. The resin material of the seal ring 32 is not limited to PTFE.

As described above, the backup ring 33 is an annular member around the axis x, and as shown in FIG. 2, for example, an inner peripheral surface 33a having a cylindrical surface or a substantially cylindrical surface with the axis x as the central axis. Have. The inner peripheral surface 33a is a surface facing the inner peripheral side of the backup ring 33, and is formed so as to come into contact with the outer peripheral surface 32b of the seal ring 32. The backup ring 33 is an elastic body formed of an elastic material such as a rubber-like elastic material, is sandwiched and compressed in the radial direction between the tubular portion 34a of the mounting ring 34 and the seal ring 32, and is compressed in the axis x direction. The width in the radial direction is set so as to generate a repulsive force. The outer peripheral surface 33b facing the outer peripheral side of the backup ring 33 is formed so as to form, for example, an annular protrusion protruding toward the outer peripheral side. In the illustrated example, the outer peripheral surface 33b forms two protrusions. Due to this protrusion, the outer peripheral side of the backup ring 33 is easily elastically deformed, and the above-mentioned repulsive force can be increased.

The backup ring 33 is provided between the outer surface 11a of the facing portion 11 of the reinforcing ring 10 facing each other and the inner surface 35b facing the inside of the facing portion 35 of the mounting ring 34. The backup ring 33 may be provided so as to be sandwiched between the outer surface 11a of the facing portion 11 and the inner surface 35b of the facing portion 35, and may be provided on the outer surface 11a of the facing portion 11 and the inner surface 35b of the facing portion 35. It may be provided with a gap between them. In the sealing device 1, when the elastically deformed backup ring 33 comes into contact with the outer surface 11a of the facing portion 11 and the inner side surface 35b of the facing portion 35, the backup ring 33 is tightened in the axis x direction. The radial repulsive force of the backup ring 33 described above can be increased. The shape of the backup ring 33 is not limited to the shape shown in the figure, and may be another shape. For example, the backup ring 33 may be an X ring, an O ring, a D ring, or the like.

The side lip portion 30, that is, the side lip 31 is integrally formed of the same elastic material as the elastic body portion 20, and examples of the elastic material of the side lip 31 include 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). Further, the mounting ring 34 is formed of a metal material, and examples of the metal material include stainless steel and SPCC (cold rolled steel).

The mounting ring 34 is manufactured by, for example, press working or forging, and the side lip portion 30 is molded by cross-linking (vulcanization) molding using a molding die. At the time of this cross-linking molding, the mounting ring 34 is arranged in the molding die, the side lip portion 30 is adhered to the mounting ring 34 by cross-linking adhesion, and the side lip portion 30 and the mounting ring 34 are integrally molded. Will be done.

The slinger 4 is an annular member attached to a shaft in the state of use of the sealing device 1 described later, and is an annular member centered on or substantially centered on the axis x. As described above, the slinger 4 has a flange portion 41, and also has a tubular portion 42 and a connecting portion 43 connecting the flange portion 41 and the tubular portion 42.

Specifically, as shown in FIG. 2, the flange portion 41 is an annular or substantially annular plate-like portion extending in the radial direction from the outer end portion of the connecting portion 43. .. The inner side surface 41a, which is a surface facing the inside of the flange portion 41, extends in the radial direction so as to be parallel to or substantially parallel to the plane orthogonal to the axis x. The tip 31a of the side lip 31 of the dust seal portion 3 comes into contact with the inner side surface 41a of the flange portion 41. The flange portion 41 may be inclined in the radial direction.

Further, the edge 41b, which is the outer peripheral edge of the flange portion 41, faces the main seal portion 2 from the inner peripheral side via the annular gap g, and this gap g forms the labyrinth seal. It has become like. Specifically, the end edge 41b of the flange portion 41 faces the main seal portion 2 from the inner peripheral side through the gap g in the tubular portion 14b of the labyrinth portion 14 of the reinforcing ring 10. As shown in FIG. 2, when the tubular portion 14b of the labyrinth portion 14 is covered with the elastic body portion 20 from the inner peripheral side, the end edge 41b of the flange portion 41 is the elastic body portion 20 covering the tubular portion 14b. A gap g is formed between the and, and a labyrinth seal is formed. On the other hand, when the tubular portion 14b of the labyrinth portion 14 is not covered with the elastic body portion 20, the edge 41b of the flange portion 41 forms a gap g with the tubular portion 14b to form a labyrinth seal.

As shown in FIG. 2, the tubular portion 42 of the slinger 4 is a tubular portion extending along the axis x, and is an outer periphery facing the outer peripheral side of a cylindrical surface or a substantially cylindrical surface with the axis x as the central axis. It has a surface 42a. The lip tip portion 23 of the main lip 21 and the inner peripheral surface 32a of the seal ring 32 are in contact with the outer peripheral surface 42a over the entire circumference.

The connecting portion 43 of the slinger 4 is connected to the tubular portion 42 at the inner end portion, is connected to the flange portion 41 at the outer end portion, and is connected to the tubular portion 42 and the flange portion 41. As shown in FIG. 2, for example, the connecting portion 43 has a shape in which the diameter increases toward the outside in the axis x direction.

Further, an elastic member 44 is attached to the inner peripheral surface 4a facing the inner peripheral side of the slinger 4. The elastic member 44 is formed of an elastic material such as a rubber elastic material and covers the inner peripheral surface 4a. In the inner peripheral surface 4a of the slinger 4 and the elastic member 44, when the shaft to be mounted is inserted into the slinger 4, the elastic member 44 is compressed in the radial direction between the shaft and the inner peripheral surface 4a of the slinger 4. , The elastic member 4 is in close contact with the outer peripheral surface of the shaft over the entire circumference. As a result, the sealing performance between the slinger 4 and the shaft can be improved in the state of use of the sealing device 1. The elastic member 44 does not have to be provided on the entire inner peripheral surface 4a of the slinger 4, and may be provided at least in a part range in the axial x direction of the tubular portion 42. Further, the slinger 4 does not have to have the elastic member 44 on the inner peripheral surface 4a. In this case, the tubular portion 42 of the slinger 4 is formed so as to be fitted to the shaft. That is, the inner diameter of the tubular portion 42 is smaller than the diameter of the outer peripheral surface of the shaft so that the tubular portion 42 can be tightened and fitted to the shaft. The slinger 4 is not limited to the one fixed by the elastic member 44 or the tubular portion 42 being fastened to the shaft, and may be fixed by being adhered to the shaft in the tubular portion 42, and other known ones. It may be fixed to the shaft by the fixing method of.

The slinger 4 is made of a metal material. For example, the slinger 4 is made of SPCC (cold rolled steel) as a base material, and the SPCC is subjected to a phosphate film treatment to prevent rust. Examples of the phosphate film treatment include zinc phosphate film treatment. The slinger 4 having high rust prevention performance can suppress the generation of rust on the flange portion 41 which is a sliding portion with respect to the side lip 31, and can maintain the sealing function and sealing performance of the side lip 31 for a long time. .. As the base material of the slinger 4, another metal having excellent rust resistance and rust prevention such as stainless steel may be used. Further, the rust preventive treatment of the base material of the slinger 4 may be another treatment such as metal plating.

As shown in FIG. 2, in the sealing device 1, the sealing ring 32 may be positioned in the axis x direction. Specifically, the inner side surface 32c facing the inside of the seal ring 32 contacts the outer surface 11a of the facing portion 11 of the reinforcing ring 10, and the outer surface 32d facing the outside of the seal ring 32 is the side lip portion 30. It comes into contact with the inner side surface 35b of the mounting portion 30a or the facing portion 35 of the mounting ring 34. The inner side surface 32c of the seal ring 32 may face the outer side surface 11a of the facing portion 11 of the reinforcing ring 10 in the axis x direction with a space. Further, the outer surface 32d of the seal ring 32 may face the mounting portion 30a of the side lip portion 30 or the inner side surface 35b of the facing portion 35 of the mounting ring 34 in the axis x direction with a space. This structure that allows the seal ring 32 to be positioned in the x-axis direction makes it possible to simplify the shape of the seal ring 32 and simplify the manufacture of the seal ring 32.

Next, the operation of the sealing device 1 having the above-described configuration will be described. FIG. 3 is a partially enlarged cross-sectional view of the sealing device 1 in a used state in which the sealing device 1 is attached to the housing 50 to be attached and the shaft 52 inserted into the shaft hole 51 which is a hole formed in the housing 50. is there. The axle 52 is, for example, the axle of a tractor which is an agricultural machine. The housing 50 internally houses a support mechanism or the like for supporting the axle 52, and the axle 52 supported in the housing 50 is the housing 50. It penetrates the shaft hole 51 of the housing 50 and protrudes to the outside of the housing 50.

As shown in FIG. 3, in the state of use of the sealing device 1, the sealing device 1 is press-fitted into the shaft hole 51 and fitted into the shaft hole 51, and the slinger 4 is tightened and fitted to the shaft 52 and attached to the shaft 52. Has been done. Specifically, the tubular portion 12 of the reinforcing ring 10 of the main seal portion 2 is press-fitted into the shaft hole 51, and the gasket portion 22 of the elastic body portion 20 is formed on the inner peripheral surface 51a of the shaft hole 51 and the reinforcing ring 10. It is compressed in the radial direction with the tubular portion 12, and the main seal portion 2 is fixed to the shaft hole 51 by the radial repulsive force of the gasket portion 22. In this state, the gasket portion 22 is in close contact with the inner peripheral surface 51a of the shaft hole 51, whereby the sealing device 1 and the shaft hole 51 are sealed. Further, the shaft 52 is press-fitted into the hollow portion of the slinger 4, and the elastic member 44 attached to the inner peripheral surface 4a of the slinger 4 is radially between the tubular portion 42 of the slinger 4 and the outer peripheral surface 52a of the shaft 52. The slinger 44 is fixed to the shaft 52 by the compressive and radial repulsive force of the elastic member 44. In this state, the elastic member 44 is in close contact with the outer peripheral surface 52a of the shaft 52, whereby the sealing device 1 and the shaft 52 are sealed.

As shown in FIG. 2, the main seal portion 2 protrudes from the outer peripheral side of the gasket portion 22 in the labyrinth seal portion 14 of the reinforcing ring 10. Therefore, when the main seal portion 2 is press-fitted into the shaft hole 51 as described above, the flange portion 14a of the labyrinth seal portion 14 comes into direct contact with the outer surface 50a of the housing 50 via the elastic body portion 20. The position of the main seal portion 2 in the housing 50 in the axis x direction is determined by the contact of the flange portion 14a of the labyrinth seal portion 14.

In the above-mentioned usage state in which the sealing device 1 is attached to the shaft 52 and the shaft hole 51, the lip tip portion 23 of the main lip 21 of the main sealing portion 2 comes into contact with the outer peripheral surface 42a of the tubular portion 42 of the slinger 4. The relative position in the axis x direction between the main seal portion 2 and the slinger 4 is determined. In addition, the axis x direction between the main seal portion 2 and the dust seal portion 3 and the slinger 4 so that the tip surface 31a of the side lip 31 of the dust seal portion 3 contacts the inner side surface 41a of the flange portion 41 of the slinger 4. The relative position in is determined. Further, in the used state, the above-mentioned gap g is formed between the end edge 41b of the flange portion 41 of the slinger 4 and the tubular portion 14b of the labyrinth seal portion 14 of the main seal portion 2 to form the labyrinth seal. As described above, the relative position between the main seal portion 2 and the slinger 4 in the axial x direction is determined.

As described above, in the state of use of the sealing device 1, the outer peripheral side and the inner peripheral side of the sealing device 1 are sealed by the gasket portion 22 of the elastic body portion 20 and the elastic member 44 of the slinger 4. Further, the lip tip portion 23 of the main lip 21 is in slidable contact with the outer peripheral surface 42a of the tubular portion 42 of the slinger 4 with respect to the main lip 21, and the main lip 21 and the slinger 4 are in contact with each other. There is a seal between them. As a result, leakage of grease or the like inside the housing 50 to the outside of the housing 50 is prevented. Further, foreign matter such as muddy water and dust is prevented from entering the housing 50 from the outside.

Further, the seal ring 32 is in sliding contact with the outer peripheral surface 42a of the tubular portion 42 of the slinger 4 with respect to the seal ring 32, and the seal between the seal ring 32 and the slinger 4 is shown in the drawing. Has been done. Further, the tip surface 31a of the side lip 31 is in slidable contact with the inner side surface 41a of the flange portion 41 of the slinger 4 with respect to the side lip 31, and between the side lip 31 and the slinger 4. Is sealed. As a result, it is possible to prevent foreign matter from entering the portion where the main lip 21 and the slinger 4 come into contact with each other from the outside. Further, the labyrinth seal formed between the edge 41b of the flange portion 41 and the labyrinth seal portion 14 of the main lip portion 2 can prevent foreign matter from entering the side lip 31 and the seal ring 32 side, and is external. It is possible to further prevent foreign matter from entering the portion where the main lip 21 and the slinger 4 come into contact with each other. Therefore, it is possible to prevent the main lip 21 from being damaged by biting foreign matter into the main lip 21, and it is possible to maintain the sealing performance of the main lip 21 for a long period of time.

Further, since the seal ring 32 is formed of a resin material, the wear of the seal ring 32 due to sliding can be reduced as compared with the wear due to sliding of the conventional rubber lip. Therefore, the blocking performance of the foreign matter that prevents the foreign matter from entering the seal ring 32 can be maintained longer than before. Further, the seal ring 32 is pushed to the inner peripheral side by the backup ring 33, and the foreign matter blocking performance of the seal ring 32 can be further improved.

Further, in the sealing device 1, the dust seal portion 3 is provided alongside the main lip 21 in the axis x direction, and the dust seal portion 3 can be provided within the radial width of the main seal portion 2. Therefore, the addition of the dust seal (side lip 31 and the seal ring 32) prevents or suppresses the radial width of the sealing device 1 from becoming larger than the radial width of the main seal portion 2. As a result, the mounting space of the sealing device 1 in the mounting target can be reduced in the radial direction. Therefore, even if the mounting space of the sealing device is limited in the radial direction, the sealing device can be mounted depending on the mounting target. Further, when the sealing device 1 is applied, the sealing device 1 can be applied to the mounting target without changing the shape of the mounting target or without significantly changing the shape of the mounting target.

As described above, the sealing device 1 according to the embodiment of the present invention can maintain the foreign matter blocking performance for a long period of time.

Although the embodiment of the present invention has been described above, the present invention is not limited to the sealing device 1 according to the embodiment of the present invention, and all aspects included in the concept of the present invention and the scope of claims. including. 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 configuration in the above embodiment can be appropriately changed depending on the specific usage mode of the present invention.

The sealing device 1 according to the embodiment of the present invention is applied to the axle and the shaft hole of the tractor, but the application target of the sealing device according to the present invention is not limited to this, and other agricultural machines. The present invention is applicable to all configurations that can utilize the effects of the present invention, such as construction machines, vehicles, general-purpose machines, and industrial machines.

1 ... Sealing device, 2 ... Main seal part, 3 ... Dust seal part, 4 ... Slinger, 4a ... Inner peripheral surface, 10 ... Reinforcing ring, 11 ... Opposing part, 11a ... Outer surface, 12 ... Cylinder part, 12a ... Outer peripheral surface , 12b ... Inner peripheral surface, 13 ... Folded part, 13a ... Curved part, 13b ... Cylinder part, 14 ... Labyrinth part, 14a ... Flange part, 14b ... Cylinder part, 20 ... Elastic body part, 21 ... Main lip, 22 ... Gasket part, 23 ... lip tip part, 24 ... concave part, 25 ... garter spring, 30 ... side lip part, 30a ... mounting part, 31 ... side lip, 31a ... tip surface, 31b ... root part, 31c ... tip part, 32 ... Seal ring, 32a ... Inner peripheral surface, 32b ... Outer surface, 32c ... Inner surface, 32d ... Outer surface, 33 ... Backup ring, 33a ... Inner peripheral surface, 33b ... Outer surface, 34 ... Mounting ring, 34a ... Cylinder , 34b ... outer peripheral surface, 35 ... opposed portion, 35a ... outer surface, 35b ... inner surface surface, 41 ... flange portion, 41a ... inner surface surface, 41b ... edge edge, 42 ... tubular portion, 42a ... outer peripheral surface, 43 ... connection portion , 44 ... elastic member, 50 ... housing, 50a ... outer surface, 51 ... shaft hole, 51a ... inner peripheral surface, 52 ... shaft, 52 ... outer peripheral surface, g ... gap, x ... axis

Claims (5)

A sealing device for sealing an annular gap between a shaft and a hole into which the shaft is inserted.
The main seal part attached to the hole and
The dust seal portion fitted to the main seal portion and
With a slinger attached to the shaft
The main seal portion has an annular reinforcing ring around the axis and an annular elastic body around the axis formed from an elastic body attached to the reinforcing ring.
The elastic body portion has a main lip which is an annular lip around the axis that contacts the slinger from the outer peripheral side.
The slinger has a flange portion which is an annular portion around the axis extending toward the outer peripheral side.
The dust seal portion is located on one side of the main lip in the axial direction, and the dust seal portion is an annular lip around the axis that contacts the flange portion from the other side in the axial direction. A sealing device comprising a side lip and a sealing ring formed of an annular resin around the axis that contacts the slinger from the outer peripheral side. The first aspect of the present invention, wherein the edge on the outer peripheral side of the flange portion faces the main seal portion from the inner peripheral side via an annular gap, and the gap forms a labyrinth seal. Sealing device. The sealing device according to claim 1 or 2, wherein the dust sealing portion has a backup ring which is an annular member around the axis that pushes the sealing ring to the inner peripheral side. The dust seal portion has a mounting ring which is an annular member around the axis, and the side lip is mounted on the mounting ring.
The reinforcing ring and the mounting ring have portions facing each other in the axial direction.
The backup ring is provided between the reinforcing ring and the mounting ring so as to face each other.
The mounting ring has a tubular portion that is a tubular portion extending along the axis and an opposing portion that is an annular portion that is a portion facing the reinforcing ring that extends from the tubular portion toward the inner peripheral side. Have and
The dust seal portion can be fitted to the main seal portion via the tubular portion of the mounting ring.
The sealing device according to claim 3, wherein the backup ring comes into contact with the tubular portion of the mounting ring from the inner peripheral side. The sealing device according to any one of claims 1 to 4, wherein an elastic member is attached to the inner peripheral surface of the slinger.

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