JPH07113377B2 - Rolling bearing sealing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing sealing device, and more particularly to an improved rolling bearing seal structure and assemblability that are sealed by a multiple structure seal. .

[Conventional technology]

2. Description of the Related Art Conventionally, as a rolling bearing for a machine or device used in a place where a lot of foreign matter such as muddy water is present, a rolling bearing having a structure shown in FIG. 2 is known.

In the figure, balls 30 are arranged as rolling elements between an outer ring (fixed side race ring) 10 fitted to the housing 1 and an inner ring (rotating side race ring) 20 fitted to the shaft 2. It shows a deep groove ball bearing. A dual seal mechanism including a pair of external seals 4 and slinger 8 is provided on the outer side of the bearing in the axial direction.

A lip portion 6 composed of an inner lip portion 6a and an outer lip portion 6b is provided on the inner peripheral side of each outer seal 4, and a radial inner side of the inner lip portion 6a and a radial outer side of the outer lip portion 6b are Lips 7a, 7b are provided respectively, and both left and right sides are fitted and attached to the inner peripheral surface of the housing 1.

Each slinger 8 has a U-shaped cross section, and the left side slinger 8 is on the outer peripheral surface of the shoulder of the shaft 2 and the right slinger 8 is the shaft on both left and right sides with the opening side of the fixing part 8b facing inward in the axial direction. The inner ring retainer 2a fitted to the outer peripheral surface of the inner ring retainer 2a is fitted and attached.

The lip 7a of the inner lip portion 6a of the left outer seal 4 is the shaft 2
On the outer peripheral surface of the shoulder of the inner lip of the right outer seal 4
The lip 7a of 6a comes into contact with the outer peripheral surface of the inner ring presser 2a in the direction of the balls 30, and contacts the outer lip 6b of each outer seal 4.
The lips 7b contact the flat annular portions of the slinger 8 in the directions opposite to the balls 30 and outward in the radial direction, and contact-type seal portions are formed at two points. Grease is filled in the space 8d between the inner lip portion 6a and the outer lip portion 6b of each outer seal 4 so that the outer lip portion
It prevents muddy water and other foreign matter entering through the 6b from entering the inside of the bearing. In addition to this, grease is also enclosed between the pair of outer seals 4.

[Problems to be solved by the invention]

In the rolling bearing provided with the sealing mechanism as described above, muddy water or the like outside the bearing is protected by the outer lip portion of the outer seal 4.
Although it accumulates on the outer periphery of 6b, the lip of the outer lip 6b
Muddy water and the like that has passed through 7b and stays in the space 8d formed between the inner lip portion 6a and the outer lip portion 6b,
The muddy water or the like overflowing from the space 8d enters the bearing from the lip 7a of the inner lip portion 6a, which leads to damage of the bearing.

Further, in the above bearing, since the pair of outer seals 4 are attached to the housing 1 and the slinger 8 is attached to the shaft 2 and the inner ring retainer 2a, respectively, the structure around the bearings is complicated, and the bearing assembly is complicated. At times, a separate process from the bearing is required, increasing the number of assembly steps as a whole.

In addition, the pair of outer seals 4 is a lip of the inner lip portion 6a.
Since the 7a is brought into contact with the outer peripheral surface of the shoulder portion of the shaft 2 and the outer peripheral surface of the inner ring retainer 2a respectively, it is necessary to grind these slidable contact surfaces to finish them to a predetermined accuracy. Become.

Further, since the axial distance between the pair of outer seals 4 is large, the amount of grease enclosed in the outer seals 4 is large, which is one of the reasons for the high cost.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a sealing device that simplifies the sealing structure of a rolling bearing sealed by a multiple sealing mechanism and has a good assembling property.

[Means for solving problems]

The sealing device of the present invention includes an inner seal attached to the outer ring on at least one shaft end side of the rolling bearing and an outer seal attached to the inner ring.

The inner seal is mounted by fitting the outer peripheral mounting portion to the inner peripheral surface of the outer ring, and has a main lip portion made of an elastic body that extends axially outward and obliquely inward. A lip portion is provided so as to be connected to the mounting portion, and an elasticity is provided between the mounting portion on the outer peripheral side and the main lip portion on the inner peripheral side, extending from the inner seal, and having a lip portion on the outer side in the axial direction and on the outer side in the radial direction. An intermediate lip portion of the body is provided. The mounting portion of the inner seal is made of an elastic body, and is provided with an auxiliary lip that branches outward from the outer mounting portion in the axial direction and contacts the inner peripheral surface of the outer ring.

The outer seal is mounted by fitting the inner peripheral side mounting part to the outer peripheral surface of the inner ring, and is connected to the outer side in the axial direction of the mounting part between the inner peripheral side and the outer peripheral side so as to be radially outward. There is an intermediate step portion that is located radially outward of the intermediate lip portion of the inner seal and extends inward in the axial direction through an annular portion that extends to the inside. An inclined portion formed of an elastic body that extends obliquely outward and having a lip portion, and a lip portion formed of an elastic body that bends radially outward from the end edge of the middle step portion and forms an inner peripheral surface of the outer ring and a seal portion. And are provided.

The lip portion of the main lip portion of the inner seal contacts the outer peripheral surface of the inner ring to form the inner seal portion, and the lip portion of the middle lip portion forms the middle seal portion with a slight clearance from the outer seal. However, the lip part of the inclined part of the outer seal is
It makes contact with the inner peripheral surface of the outer ring to form an outer peripheral seal portion.

Of the space surrounded by the inner seal and the outer seal and partitioned between the outer ring and the inner ring, grease is sealed in at least the space on the inner peripheral side of the intermediate lip of the inner seal.

[Action]

In the sealing device of the present invention, muddy water outside the bearing is prevented from entering the inside by the outer peripheral side seal portion formed between the lip portion of the inclined portion of the outer seal and the inner peripheral surface of the outer ring. .

The muddy water that has entered through the outer peripheral side seal part is prevented from leaking to the inner peripheral side by the seal part formed between the lip part of the middle part of the outer seal and the inner peripheral surface of the outer ring. In addition, since the auxiliary lip of the inner seal mounting portion is in contact with the inner peripheral surface of the outer ring, the inner seal mounting portion is prevented from entering the bearing and the middle lip portion of the inner seal and the middle stage of the outer seal are blocked. The muddy water accumulated in the space formed between the inner part and the inner part is prevented from entering the inside by the intermediate seal part formed between the intermediate lip part of the inner seal and the middle part of the outer seal. It

Even if muddy water staying in this space passes through the intermediate seal part and enters, the inner seal part between the main seal lip part of the inner seal and the inner ring seals the inside. Is prevented from entering.

Since grease is filled in the space on the inner peripheral side of the intermediate lip of the inner seal, the amount of muddy water that can pass through the intermediate seal and enter the space on the inner peripheral side of the intermediate lip is limited to a very small amount. It

Further, the muddy water accumulated on the outer peripheral side of the intermediate lip portion easily flows toward the outer peripheral side seal portion because the intermediate lip portion functions as a gutter.

〔Example〕

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

FIG. 1 is a vertical sectional side view of an upper half portion showing an embodiment of the present invention.

The bearing in this embodiment is a wide bearing in which both end portions in the axial direction of the outer ring 10 and the inner ring 20 respectively extend outward in the axial direction, and the bearing itself has a pair of inner seal 40 and outer seal, respectively. 50 and is assembled.

In the figure, reference numeral 1 is a housing, 1a is a retaining ring for fixing an outer ring, 2 is a shaft, 2a is an inner ring retainer, 30 is a ball, and 31 is a cage, respectively.

A peripheral groove 11 for mounting an inner seal is formed on the inner peripheral surface axially inward of both end surfaces of the outer ring 10, and an inner seal sliding contact is formed on an outer peripheral surface axially inner than both end surfaces of the inner ring 20. Is formed with a slope 21.

On the inner peripheral surface of the outer ring 10 axially outside the peripheral groove 11,
A large diameter portion 13 for sliding contact with the outer seal is formed as a cylindrical surface through 12, and a small diameter portion 23 for mounting the outer seal is formed as a cylindrical surface on the outer peripheral surface axially outside of the inclined surface portion 21 of the inner ring 20. Has been done.

The inner seal 40 includes a mounting portion 42 made of an elastic body such as rubber or synthetic resin, a main lip portion 44, and an intermediate portion on an outer peripheral side, an inner peripheral side and an intermediate portion of an annular portion (core bar) 41 made of a metal body. The lip portion 47 is integrally formed.

An auxiliary lip 43 is provided on the outer peripheral surface of the mounting portion 42 of the inner seal 40 so as to be branched outward in the axial direction via an annular groove. The main lip portion 44 has an axially outer slanting inner side at its inner peripheral edge, that is, a lip portion 45 extending in a direction that prevents intrusion of muddy water, and an axial inner side branching from the outer peripheral side of the main lip portion 44. An auxiliary lip 46 extending obliquely inward is provided. Further, in the intermediate lip portion 47, a cylindrical or conical tubular portion 48 that extends axially outward from the inner seal 40, and a lip portion 49 that bends radially outward from an axial outer end edge thereof.
And are provided.

The outer seal 50 includes a cylindrical mounting portion 52 on the inner peripheral side and the mounting portion 52.
An annular portion 53 that is connected to the axially outer end edge of 52 and is bent outward in the radial direction is formed of a metal body, and an intermediate step portion 54 made of an elastic body such as rubber or synthetic resin is provided on the outer peripheral side of the annular portion 53 and the inclination The part (main lip part) 57 is integrally formed. A portion of the outer seal 50 that faces the inner seal 40 in the axial direction is located outside in the axial direction.

The middle portion 54 of the outer seal 50 has a tubular portion 55 extending obliquely outward in the axial direction from the outer peripheral edge of the annular portion 53, and a lip portion 56 bending outward in the radial direction from the axial inner end edge. It is provided. The inclined portion 57 has a lip portion on the outer peripheral edge that extends outward in the axial direction through a bent portion that extends radially outward from the intermediate position of the middle step portion 54, that is, the outer peripheral edge that is extended by turning in a direction that prevents intrusion of muddy water and the like. 58 are provided.

The inner seal 40 and the outer seal 50 have their respective mounting portions 42 and 52 fitted into the circumferential groove 11 of the outer ring 10 and the small diameter portion 23 of the inner ring 20 so that the respective constituent parts have a predetermined relationship with each other. It will be assembled with the position maintained.

Auxiliary lip 43 of the mounting portion 42 of the assembled inner seal 40
Is a contact-type seal portion on the outer peripheral side in contact with the medium diameter portion 12 of the outer ring 10 toward the outer side in the axial direction, and the lip portion 45 of the main lip portion 44 has the lip portion 45 of the inner ring 20 toward the outer side in the axial direction. It contacts the sloped part 21 to form a contact type inner peripheral side seal part, and the main lip part
The auxiliary lips 46 of 44 form a non-contact type seal portion in the axial direction inwardly close to the shoulder of the inner ring 20 with a slight gap therebetween, and the intermediate lip portion 47 forms the middle step portion 54 of the outer seal 50. Located on the inner peripheral side of the outer seal 50
It is close to the inner peripheral surface of the intermediate step portion 54 with a slight gap therebetween, and constitutes a non-contact type intermediate seal portion between the outer peripheral side and the inner peripheral side.

Further, the lip portion 58 of the inclined portion 57 of the outer seal 50 contacts the large diameter portion 13 of the outer ring 10 toward the axially outer side to form a contact-type outer peripheral side seal portion, and the lip portion 56 of the middle step portion 54. Is
A non-contact type seal portion is formed in close proximity to the medium diameter portion 12 of the outer ring 10 with a slight clearance.

Between the outer ring 10 and the inner ring 20 that are sealed by the inner seal 40 and the outer seal 50 that form the above-described seal portion, a middle step portion 54 of the outer seal 50 and an intermediate lip portion 47 of the inner seal 40 are provided. Space sections 60, 61, 62 divided into three sections are formed so as to communicate with each other. Grease is filled in these space portions 60, 61, 62, and this grease is applied to the large diameter portion 13 of the outer ring 10.
The contact-type outer peripheral side seal portion between the outer seal 50 and the inclined portion 57 of the outer seal 50 prevents leakage to the outside of the bearing.

The middle step portion 54 of the outer seal 50 and the intermediate lip portion 47 of the inner seal 40 in the space portions 61 and 62 also have a function as a foreign matter reservoir for muddy water or the like.

In the bearing having the above configuration, the auxiliary lip 46 on the inner peripheral side of the inner seal 40 has an action of guiding the lubricating grease enclosed in the inner seal 40 to the ball 30 side and flowing the grease to the outside of the bearing. The leakage of this grease to the outside of the bearing is also prevented by the contact-type inner peripheral seal portion between the main lip portion 44 and the inner ring 20.

When the above bearing is used, for example, in a place where a large amount of muddy water is present, this muddy water has a shaking action due to the centrifugal force of the inclined portion 57 of the outer seal 50 that extends obliquely outward in the axial direction, and the outer ring.
The outer peripheral side seal portion of the lip portion 58 of the inclined portion 57 which is in sliding contact with the large diameter portion 13 of 10 prevents entry into the bearing.

Even if muddy water tries to pass through this outer peripheral side seal part, the space 60, 61, 62 between the outer seal 50 and the inner seal 40 is filled with grease, so the amount of muddy water that can enter is very small. The muddy water that has entered and stays in the space portion (reservoir portion) 60 formed by the middle step portion 54 of the outer seal 50. Since the lip portion 56 of the middle step portion 54 constitutes a non-contact type seal portion with the middle diameter portion 12 of the outer ring 10, the accumulated mud water leaks to the inner peripheral side through the seal portion. Since it is prevented from entering and the auxiliary lip 43 of the mounting portion 42 of the inner seal 40 is in sliding contact with the medium diameter portion 12 of the outer ring 10 to form a seal portion, this seal portion prevents intrusion into the bearing interior. Be blocked.

Even if this accumulated muddy water passes through the seal portion formed by the middle portion 54 of the outer seal 50, a space portion (collection portion) 61 formed by the intermediate lip portion 47 of the inner seal 40 on the inner peripheral side thereof.
Since it is formed, it will be retained again in this space portion (reservoir portion) 61, and further, the lip portion 49 of the intermediate lip portion 47 and the middle step portion 54 of the outer seal 50 will be a non-contact type intermediate portion. Since the seal portion is configured, it is prevented from leaking into the inner peripheral side through the intermediate seal portion.

In addition, the accumulated mud collects in the middle lip portion 47 of the inner seal 40.
The main lip portion 44 of the inner seal 40, even when it passes through the intermediate seal portion and leaks into the space portion 62 on the inner peripheral side thereof.
Since the contact-type inner peripheral side seal portion is formed between the inner ring 20 and the inner ring 20, the intrusion into the bearing is prevented.

In the above-described embodiment, the case where the double-sided seal mechanism in which the inner seal and the outer seal are combined is provided at the shaft ends on the left and right sides of the bearing is described. Depending on the type, the mounting position of the bearing, etc., only one of the shaft end sides may have the double seal structure according to the present invention.

Further, the present invention is not limited to the deep groove ball bearing described in the above embodiment, but can be applied to other rolling bearings in the same manner as described above.

Furthermore, a metal body portion of the inner seal having a front surface coated with rubber or synthetic resin can also be used.

〔The invention's effect〕

As described above, in the sealing device of the present invention, the inner seal having the main lip portion, the intermediate lip portion, and the auxiliary lip is attached to the outer ring on the shaft end side of at least one of the rolling bearings, and the inner ring has the middle step portion and the inclined portion. A main seal of the inner seal, the inner seal on the inner peripheral side is in contact with the inner ring, and the middle lip is a non-contact intermediate seal on the outer seal. , The auxiliary lip forms a seal part with the outer ring, the inclined part of the outer seal forms a contact type outer seal part with the outer ring, and the middle part forms a seal part with the outer ring. The grease is sealed in at least the space on the inner peripheral side of the space defined by the inner and outer rings and surrounded by the inner seal and the outer seal.

In the present invention, as the seal portion for the bearing outer ring, there are two seal portions by the lip portion of the inclined portion of the outer seal and the middle step portion, and further, the seal portion by the auxiliary lip is provided at the attachment portion of the inner seal. Because there is
At the inner seal mounting location on the outer peripheral side of the bearing close to the atmosphere,
It is possible to reliably prevent muddy water that passes between the inner seal and the outer ring and enters the bearing.

In addition, the bearing has seal portions at three locations, namely, the inner circumference and the outer circumference, and the middle between the inner circumference and the inner circumference. Since it faces the direction of preventing the intrusion of muddy water, the intrusion of muddy water into the bearing is reduced.

Also, since the inner seal and the outer seal can be handled as a bearing with multiple seals that are integrally assembled inside the bearing, the process of assembling the bearing can be simplified and the assembly man-hours can be significantly reduced. Becomes

Further, since the main lip portion of the inner seal or the lip portion of the inclined portion of the outer seal constitutes the seal portion with the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring, respectively, the bearing of this type of conventional bearing is The process of specially grinding the shoulder of the shaft, the inner ring retainer, etc. is also unnecessary.

Further, since the inner seal and the outer seal are assembled integrally with the bearing, not only the space of the space between these seals is narrowed but also the space between the pair of inner seals can be shortened. A small amount of grease is filled in these spaces, and the sealing device becomes a low cost.

Therefore, according to the present invention, the rolling bearing sealing device has an excellent sealing function due to the multiple structure, does not require maintenance management such as replenishment of lubricating grease, and has a simple structure and good assemblability. Is obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an upper half of an embodiment of the present invention,
FIG. 2 is a vertical cross-sectional side view showing an upper half portion of a conventional deep groove ball bearing sealing device. In the figure, 10 is an outer ring, 20 is an inner ring, 40 is an inner seal, 42 is an inner seal attachment portion, 43 is an auxiliary lip of an inner seal attachment portion, 44 is a main lip portion of the inner seal, 45 is a lip portion thereof, 47 is an intermediate lip portion of the inner seal, 49 is a lip portion thereof, 50 is an outer seal, 52 and 53 are attachment portions of outer seals respectively, an annular portion, 54 is a middle portion of the outer seal, 56 is a lip portion thereof, and 57 is a lip portion. The outer seal slope, 58 is its lip,
Reference numerals 61 and 62 respectively denote an outer peripheral side space portion and an inner peripheral side space portion of the intermediate lip portion of the inner seal.

 ─────────────────────────────────────────────────── ───Continued from the front page (56) References Shou 49-124444 (JP, U) Seki 61-81013 (JP, U) Seki 60-77818 (JP, U) Seki 59- 67624 (JP, U) Actual public 54-39547 (JP, Y2) Actual public 53-41641 (JP, Y2)

Claims (2)

[Claims] 1. A sealing device in which at least one shaft end side of a rolling bearing containing lubricating grease is hermetically sealed, and an inner seal of an inner seal attached to a shaft end side portion of an outer ring has an axial outer side. A main lip portion is provided that has a lip portion made of an elastic body that extends obliquely inward, and between the main lip portion and the mounting portion on the outer peripheral side, the main lip portion extends from the inner seal and is axially outer and radial. An intermediate lip portion made of an elastic body having a lip portion on the outer side is provided, and the mounting portion of the inner seal is made of an elastic body, and is branched from the mounting portion to the oblique outer side in the axially outer direction to the inner peripheral surface of the outer ring. The outer seal, which is provided with an auxiliary lip that comes into contact with the inner ring and is located axially outside of the inner seal, is attached to the inner ring. Axially inward through A lip that is formed of an elastic body that has a middle step portion that extends once is located radially outside of the intermediate lip portion of the inner seal, and that turns outward from the middle step portion and extends obliquely outward in the axial direction on the outer peripheral side. The main lip portion of the inner seal is provided with an inclined portion having a portion and a lip portion made of an elastic body that bends outward in the radial direction from the end edge of the middle step portion and constitutes the inner peripheral surface of the outer ring and the seal portion. The lip portion of the inner ring contacts the outer peripheral surface of the inner ring to form the inner peripheral side seal portion, and the lip portion of the intermediate lip portion forms the intermediate seal portion with a slight clearance from the outer seal. The lip portion of the portion makes contact with the inner peripheral surface of the outer ring to form an outer peripheral side seal portion, and at least the inner side of the space portion surrounded by the inner seal and the outer seal and partitioned between the outer ring and the inner ring. Within the middle lip of the seal Sealing device of the rolling bearing, characterized in that encapsulating grease to the space portion side. 2. An auxiliary lip which is branched from the main lip portion of the inner seal inwardly inward in the axial direction and is close to the outer peripheral surface of the inner ring with a slight gap therebetween. Rolling bearing sealing device.