JP3701732B2 - Oil seal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oil seal used for, for example, a sealed bearing of a work roll neck of a rolling mill.
[0002]
[Prior art]
Conventionally, there is a labyrinth seal as an oil seal of a work roll neck of a rolling mill. This labyrinth seal has a maze structure that is opposed to the peripheral surface of the shaft with a predetermined gap. According to this labyrinth seal, the grease that is excessively filled in the space inside the seal can be discharged from the predetermined gap, so that the temperature of the grease can be prevented from rising excessively, Prevents poor lubrication and bearing seizure.
[0003]
However, since this labyrinth seal has the said clearance gap between the surrounding surfaces of a shaft, there exists a problem that water penetrate | invades into the inside from the exterior of a seal | sticker.
[0004]
As another oil seal, there is a type in which an annular elastic body is in close contact with the peripheral surface of the shaft so that the elastic body does not lift from the peripheral surface of the shaft while the shaft is rotating. This type can prevent water from entering, but cannot discharge excess grease. On the other hand, in the type in which the elastic body is lifted during the rotation of the shaft, excess grease can be discharged, but there is a risk of water intrusion.
[0005]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide an oil seal capable of discharging excess grease from the inside to the outside and preventing water from entering from the outside to the inside.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an oil seal of the invention of claim 1 comprises a ring body,
A plurality of arc-shaped elastic division pieces arranged to be continuous in the circumferential direction along the ring body and fixed to the ring body so as to protrude radially inward from the ring body,
The radially inner edges of the plurality of arc-shaped divided pieces are in sliding contact with the peripheral surface of the shaft member ,
The circumferential edge of the arc-shaped segment is inclined in the rotational direction of the shaft member from the outside in the radial direction to the inside .
[0007]
According to the first aspect of the present invention, during the rotation of the shaft, excess grease in the axial direction can be discharged to the outside from the joint between the arc-shaped divided piece and the divided piece. Therefore, the temperature rise and deterioration of the grease can be prevented. Further, since the grease is clogged in the joint, it is possible to prevent water from entering the inside from the outside.
[0008]
Further, according to the first aspect of the present invention, since the sealing member is constituted by a plurality of divided pieces, the sealing member has low rigidity as compared with the conventional example having an annular integral sealing member. Therefore, the followability with respect to the eccentricity of the shaft can be improved. In addition, since the mold for producing the seal member can be reduced in size, the mold unit price can be reduced, and it is easy to cope with high-mix low-volume production, and the divided pieces can be cut out from the sheet-like material without waste. Cost can be reduced.
[0009]
The invention of claim 1, the circumferential edge of the upper Symbol arcuate split pieces comprises, from the outside of the radially inward, that are inclined in the rotational direction of the shaft member.
[0010]
According to invention of Claim 1 , compared with the case where the said edge is not inclined, the seam of the said arc-shaped division | segmentation piece and a division | segmentation piece can be lengthened. Accordingly, excessive grease inside can be easily discharged from the joint to the outside during the rotation of the shaft. Further, the inclination of the seam is an inclination in the rotation direction of the shaft member from the outer side in the radial direction to the inner side. Therefore, the seam can promote grease discharge by guiding the grease dragged by the rotation of the shaft member in the rotational direction and radially inward.
[0011]
The invention of claim 2 is characterized in that, in the oil seal according to claim 1, the end portion in the circumferential direction of the arc-shaped divided piece is overlapped with the end portion of the adjacent divided piece. .
[0012]
Therefore, according to the second aspect of the present invention, the ability to retain the grease at the end can be improved as compared with the case where the end and the end of the divided piece are just abutted with each other. it can. In addition, since the dimensional accuracy of the end portion can be relaxed compared to the case where the end portion and the end portion are abutted with each other, processing becomes easy.
[0013]
Further, the invention according to claim 3 is the oil seal according to claim 2 , wherein the axially outer end portion of the overlapped end portions is radially inward than the axially inner end portion. It is characterized by protruding.
[0014]
Therefore, according to the invention of claim 3 , when the axially outer end portion and the axially inner end portion of the overlapped divided pieces are bent outward in the axial direction, the axially outer end portion is It can be prevented from being lifted off the peripheral surface of the shaft by being pushed outward in the axial direction by the end portion on the inner side in the axial direction, and a decrease in the sealing ability of the overlapping portion can be prevented.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.
[0016]
FIG. 1 shows ten arc-shaped elastic division pieces 1 included in an embodiment of the oil seal of the present invention. FIG. 1 shows a state viewed from the outside in the axial direction toward the inside. The ten divided pieces 1 constitute a seal member 4. The segment 1 is made of Teflon, but may be made of synthetic rubber or synthetic resin. In FIG. 1, an arrow 6 indicates the rotation direction of the shaft 3 as the shaft member shown in FIG. FIG. 2A partially shows a state in which the seal member 4 is seen from the radially inner side to the radially outer side.
[0017]
The ten arc-shaped divided pieces 1 shown in FIG. 1 are arranged so as to be continuous in the circumferential direction along the cored bar 2 as a ring body partially shown in FIG. FIG. 4 shows the state of assembly when viewed from the axially inner side toward the axially outer side. The cored bar 2 is bent in an L shape, and a plurality of through holes 11 are formed in the bent part 10 at predetermined intervals in the circumferential direction. On the other hand, four through-holes 12 are also formed in the divided piece 1 in the circumferential direction at a predetermined interval. As shown in FIG. 3, the split piece 1 is overlapped on the bent portion 10 of the core metal 2 via a rubber covering material 13, and the pressing member 15 is sandwiched between the split pieces 1 from the inner side in the axial direction. Overlaid. The divided piece 1 is fixed to the cored bar 2 with a rivet 16 that penetrates the through hole 15 A of the pressing member 15, the through hole 12 of the divided piece 1, and the through hole 11 of the cored bar 2.
[0018]
Further, as shown in FIG. 3, the inner edge 1 </ b> A in the radial direction of the arc-shaped divided pieces 1 arranged in an annular shape is in sliding contact with the peripheral surface 3 </ b> A of the shaft 3 as a shaft member and protrudes from the core metal 2. The portion 5 is curved from the inner side to the outer side in the axial direction.
[0019]
As shown in FIG. 1, the inner edge 7 </ b> A of the rear portion 7 in the divided piece 1 is inclined in the rotational direction of the shaft 3 from the radially outer side toward the radially inner side. Further, the rear portion 7 of the divided piece 1 is overlapped inside the front portion 8 of the divided piece 1 adjacent to the rear in the rotation direction. Further, as shown in FIG. 1, the axially outer front part 8 of the overlapped rear part 7 and front part 8 protrudes inward in the radial direction from the axially inner rear part 7. It has a protruding portion 8A.
[0020]
The oil seal having the above configuration can discharge excess grease in the axial direction to the outside from the joint 17 between the arc-shaped divided piece 1 and the divided piece 1 while the shaft 3 is rotating. Therefore, the temperature rise and deterioration of the grease can be prevented. Further, since the seam 17 is clogged with grease, it is possible to prevent water from entering the inside from the outside.
[0021]
Further, according to this oil seal, since the seal member 4 is constituted by the plurality of divided pieces 1, the seal member has low rigidity as compared with the conventional annular integral seal member. Therefore, the followability to the eccentricity of the shaft 3 can be improved. In addition, since the mold for producing the seal member can be reduced in size, the unit price of the mold can be reduced, and it is easy to cope with a variety of small-quantity production, and the divided pieces 1 can be cut out from the sheet-like raw material without waste. Cost reduction can be achieved.
[0022]
Further, according to this oil seal, the inner edge 7A of the rear part 7 in the divided piece 1 in the rotational direction is inclined in the rotational direction of the shaft 3 from the radially outer side toward the inner side, Compared to the case where the inner edge 7A is not inclined, the joint 17 between the divided piece 1 and the divided piece 1 can be lengthened. Therefore, it becomes easy to discharge excess grease from the seam 17 to the outside. Further, since the inclination of the seam 17 is an inclination from the radially outer side to the inner side in the rotation direction of the shaft 3, the seam 17 is dragged during the rotation of the shaft 3 during the rotation of the shaft 3. Can be guided in the rotational direction and radially inward to facilitate the discharge of grease.
[0023]
Further, in the oil seal, since the rear portion 7 of the divided piece 1 is superimposed on the inner side of the front portion 8 of the divided piece 1 adjacent to the rear in the rotation direction, the rear portion 7 and the front portion 8 are simply abutted against each other. Compared to the above, it is possible to improve the grease holding ability at the rear portion 7 and the front portion 8. Therefore, waterproof performance can be improved. Further, as compared with the case where the rear portion 7 and the front portion 8 are abutted, an annular seal member can be configured with a loose dimensional accuracy, so that the processing of the divided piece 1 is simplified.
[0024]
The oil seal includes an inward protruding portion in which the axially outer front portion 8 of the overlapped rear portion 7 and front portion 8 protrudes radially inward from the axially inner rear portion 7. 8A. Therefore, as shown in FIG. 2 (B), when the front part 8 is in sliding contact with the circumferential surface 3A of the shaft 3 and the front part 8 and the rear part 7 are bent outward in the axial direction, the front part 8 8A can be brought into sliding contact with the peripheral surface 3A of the shaft 3. Therefore, it is possible to prevent a decrease in the sealing ability of the overlapping portion. On the other hand, when the front part 8 does not protrude radially inward from the rear part 7, the front part 8 is pushed axially outward by the rear part 7 as shown in FIG. Since it floats up from 3 A of surrounding surfaces of the shaft 3, sealing performance will fall.
[0025]
In the above embodiment, the seal member 4 is composed of ten divided pieces 1. However, the number of divisions may be set according to the shaft diameter or the like. Moreover, in the said embodiment, although the front part 8 and the rear part 7 of the division | segmentation piece 1 were piled up, even if it makes several division | segmentation pieces continue in the circumferential direction so that the front end and rear end of a division | segmentation piece may be faced | matched Good. However, the waterproof performance can be improved by superimposing the front and rear portions of the split pieces as in the above embodiment.
[0026]
【The invention's effect】
As is clear from the above, the oil seal of the invention of claim 1 is arranged so as to be continuous in the circumferential direction along the ring body and protrudes radially inward from the ring body. And a plurality of arc-shaped elastic segment pieces fixed to the ring body, and radially inner edges of the plurality of arc-shaped segment pieces are in sliding contact with the peripheral surface of the shaft member.
[0027]
According to the first aspect of the present invention, during the rotation of the shaft, excess grease in the axial direction can be discharged to the outside from the joint between the arc-shaped divided piece and the divided piece. Therefore, the temperature rise and deterioration of the grease can be prevented. Further, since the grease is clogged in the joint, it is possible to prevent water from entering the inside from the outside. Further, according to the first aspect of the present invention, since the sealing member is constituted by a plurality of divided pieces, the sealing member has low rigidity as compared with the conventional example having an annular integral sealing member. Therefore, the followability with respect to the eccentricity of the shaft can be improved. In addition, since the mold for producing the seal member can be reduced in size, the mold unit price can be reduced, and it is easy to cope with high-mix low-volume production, and the divided pieces can be cut out from the sheet-like material without waste. Cost can be reduced.
[0028]
According to a first aspect of the present invention, the circumferential edge of the arc-shaped segmented piece is inclined in the rotational direction of the shaft member from the outside in the radial direction to the inside.
[0029]
According to invention of Claim 1 , compared with the case where the said edge is not inclined, the seam of the said arc-shaped division | segmentation piece and a division | segmentation piece can be lengthened. Accordingly, excessive grease inside can be easily discharged from the joint to the outside during the rotation of the shaft. Further, the inclination of the seam is an inclination in the rotation direction of the shaft member from the outer side in the radial direction to the inner side. Therefore, the seam can promote grease discharge by guiding the grease dragged by the rotation of the shaft member in the rotational direction and radially inward.
[0030]
According to a second aspect of the present invention, in the oil seal according to the first aspect, an end portion in the circumferential direction of the arc-shaped divided piece is overlapped with an end portion of an adjacent divided piece.
[0031]
Therefore, according to the second aspect of the present invention, the ability to retain the grease at the end can be improved as compared with the case where the end and the end of the divided piece are just abutted with each other. it can. In addition, since the dimensional accuracy of the end portion can be relaxed compared to the case where the end portion and the end portion are abutted with each other, processing becomes easy.
[0032]
Further, the invention according to claim 3 is the oil seal according to claim 2 , wherein the axially outer end portion of the overlapped end portions is radially inward than the axially inner end portion. Sticks out.
[0033]
Therefore, according to the invention of claim 3 , when the axially outer end portion and the axially inner end portion of the overlapped divided pieces are bent outward in the axial direction, the axially outer end portion is It can be prevented from being lifted off the peripheral surface of the shaft by being pushed outward in the axial direction by the end portion on the inner side in the axial direction, and a decrease in the sealing ability of the overlapping portion can be prevented.
[Brief description of the drawings]
FIG. 1 is a view showing a state where an oil seal according to an embodiment of the present invention is viewed from the outside in an axial direction.
FIG. 2 (A) is a partial view showing the seal member as viewed from the inside in the radial direction to the outside, and FIG. 2 (B) shows the overlapped portion of the seal member in sliding contact with the shaft. FIG. 2C is a diagram showing a state where another overlapping portion is in sliding contact with the shaft and bent outward in the axial direction.
FIG. 3 is a cross-sectional view showing a state in which a seal member is fixed to a metal core in the oil seal.
FIG. 4 is a diagram for explaining the assembly procedure of the oil seal.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Divided piece, 1A ... Inner edge, 2 ... Core metal, 3 ... Shaft, 3A ... Circumferential surface,
4 ... sealing member, 5 ... protruding part, 7 ... rear part, 7A ... inner edge,
8 ... front part, 8A ... inward projecting part, 10 ... bent part, 11 ... through hole,
12 ... Through hole, 13 ... Coating material, 15 ... Presser material, 15A ... Through hole,
16 ... Rivet, 17 ... Seam.

Claims (3)

An annulus,
A plurality of arc-shaped elastic division pieces arranged to be continuous in the circumferential direction along the ring body and fixed to the ring body so as to protrude radially inward from the ring body,
The radially inner edges of the plurality of arc-shaped divided pieces are in sliding contact with the peripheral surface of the shaft member ,
The oil seal according to claim 1, wherein an edge in a circumferential direction of the arc-shaped divided piece is inclined in a rotation direction of the shaft member from an outer side in a radial direction to an inner side . The oil seal according to claim 1,
An oil seal, wherein an end portion in the circumferential direction of the arc-shaped divided piece is overlapped with an end portion of an adjacent divided piece. The oil seal according to claim 2 ,
An oil seal characterized in that an axially outer end portion of the overlapped end portions protrudes radially inward from an axially inner end portion.

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