JP2003148495A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely prevent invasion of oil dropping to a side surface of a rolling bearing installed on a shaft in a vertical attitude into a bearing inner surface. SOLUTION: On the upper side of this rolling bearing installed on the shaft in the vertical attitude, a seal member 9 to contactlessly seal the inside of the bearing is disposed. An outer diameter end of the seal member 9 is fixed to an outer ring on the rotating side. A first protruded part 15 is provided on a side surface of the seal member 9, and the inner diameter side of an oil sump part 13 is parted by the first protruded part 15 in a circular direction. The oil sump part 13 is thus formed on a side surface 9c of the seal member 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing used for a shaft in a vertical posture, and is particularly suitable as a bearing used for a film stretching machine for processing a thermoplastic resin into a film by injection molding.

[0002]

2. Description of the Related Art A film stretching machine comprises an extruder, a die head, a cooling device, a longitudinal stretching device, a transverse stretching device, and a take-up winder, which are successively arranged on a processing line.
The molten resin discharged from the die head via the extruder is cooled and formed into a sheet by a cooling device. Then, it is stretched in the longitudinal direction by a multi-stage roll and further stretched in the transverse direction by a tenter clip of a transverse stretching device. The stretched film is wound on a roll after heat treatment.

Of these devices, the transverse stretching apparatus is an apparatus for cooling a sheet into a sheet and then stretching the film stretched in the machine direction by a multi-stage roll further in the transverse direction. The transverse stretching device is connected to each of the guide rails, which are arranged on both the left and right sides of the film being fed, and in which the distance between the guides is gradually widened in the traveling direction of the line, and which are connected in a roller chain shape. A plurality of tenter clips circulate on the rail in the traveling direction of the line.

As shown in FIG. 3, the tenter clip 30 has a grip portion 32 for gripping the end portion of the film 31, and guide bearings 35, 36 rolling on guide rails 33, 34 formed of a closed loop. . In the transverse stretching device, the tenter clip 30 has the clip portion 32 and the film 31.
With both ends of the film being held, it has a role of advancing in the traveling direction along the guide rails 33 and 34 and stretching the film 31 in the lateral direction. There are two types of guide rails 33 and 34, one having its guide surface oriented in the horizontal direction and one having its guide surface oriented in the vertical direction. The guide bearings 35 and 36 of the tenter clip 30 have a role of rolling and guiding the tenter clip 30 along the guide rails 33 and 34, and roll the horizontal guide surface of the guide bearings 35 and 36. The guide bearing 35 is a fixed shaft 37 in the horizontal direction (sideways posture).
Further, the guide bearings 36 rolling on the vertical guide surface are mounted on the fixed shafts 38 in the vertical direction (vertical posture), respectively.

As the guide bearings 35, 36, deep groove ball bearings and double row angular contact ball bearings are often used. Figure 4
Is an example of a deep groove ball bearing as a guide bearing, and shows a guide bearing 36 attached to a fixed shaft 38 in a vertical posture. The guide bearing 36 has a structure in which the inner ring 41 is attached to the fixed shaft 38 and the outer ring 43 is brought into rolling contact with the guide rail 34.

Sealing members 49 are provided at both axial ends of the rolling bearing from the viewpoints of preventing leakage of the lubricant enclosed inside and preventing dust and water from entering the bearing. There are contact type and non-contact type seal members 49 for general rolling bearings.
Then, since the outer ring 43 rotates at a high speed, a non-contact type seal member 49 is used in which the temperature rise of the seal member and the wear of the seal lip are not a problem. Guide bearing 35,
As the lubricant of No. 36, a fluorine-based lubricant that withstands a use temperature of 200 ° C. or higher is often used.

[0007]

By the way, of the two types of guide bearings 35 and 36, the guide bearing 36 used for the vertical fixed shaft 38 is attached to the upper guide rail 32 and the tenter clip 31. General lubricating oil drops on the side surface of the bearing (the surface perpendicular to the center axis of the bearing). The dropped oil enters the inside of the bearing through the seal clearance between the seal member 49 and the inner ring 41, so that the fluorine-based lubricant inside the bearing, which has a higher specific gravity than general oil, may flow out of the bearing. However, such a situation is not preferable because it causes deterioration of the bearing performance.

[0008] Therefore, an object of the present invention is to provide a rolling bearing which can surely prevent the oil that has dropped from entering the inner space of the bearing.

[0009]

[Means for Solving the Problems] To achieve the above object,
The present invention relates to a rolling bearing having a seal member that is mounted on a shaft in a vertical posture and seals the inside of the bearing at least at the upper portion, and one end of the seal member is fixed to a rotating side member. Is formed.

By forming such an oil reservoir, the oil dropped on the upper seal member is retained by the oil reservoir formed on the outer side surface thereof. Further, since the seal member rotates with the rotation of the rotary member, the oil retained in the oil sump is shaken off toward the outer diameter side by the centrifugal force. From the above, it is possible to avoid the situation where oil enters the inside of the bearing through the seal portion between the seal member and the fixed member regardless of whether the bearing is stopped or in operation. In this case, if the outer diameter end of the seal member is fixed to the rotation side member and the seal portion is formed on the inner diameter side of the seal member, the oil shaken off to the outer diameter side will not pass through the seal portion, It is possible to more reliably prevent the intrusion into the bearing.

If a first projection is provided on the side surface of the seal member and the inner diameter side of the oil sump is partitioned by the first projection in the circumferential direction, the oil will flow into the inner diameter side by the first projection. Since it is blocked, it is possible to prevent the oil from flowing into the seal portion.

If a second protrusion is provided on the side surface of the seal member and the outer diameter side of the oil sump is partitioned by the second protrusion in the circumferential direction, the seal member moves to the outer diameter side by centrifugal force due to rotation of the seal member. The oil thus formed is guided by the second protrusions and scattered outward in the oblique direction rather than in the radial direction, so that the effect of shaking off the oil is enhanced.

The rolling bearing described above is rotatably supported by the guided member of the film stretching machine, and rolls on the guide rail of the film stretching machine to guide the guided member along the guide rail. It can be used as a guide bearing. This prevents the oil dropped from the guide rails from entering the guide bearing, so that the function of the bearing can be prevented from deteriorating and the guiding function of the guided member can be stably maintained for a long period of time.

If the seal member is a non-contact type and a gap (seal gap) is formed in the seal portion between the other end side of the seal member and the fixed side member, the seal member and the fixed side member come into contact with each other. It is possible to avoid the temperature rise of the seal member and the wear of the seal lip.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.
It will be described with reference to FIG.

FIG. 1 is a sectional view of a rolling bearing used in the transverse stretching device of the film stretching machine described above. This rolling bearing is used as a guide bearing mounted on a tenter clip as a guided member of a lateral stretching device. Specifically, the rolling bearing is mounted on a fixed shaft 38 of the tenter clip 30 in a vertical posture shown in FIG. To be done. This rolling bearing is shown in FIG.
Inner ring 1 having raceway surface on the outer circumference, as in the conventional product shown in
An outer ring 3 having a raceway surface on the inner circumference, and balls 5 as a plurality of rolling elements incorporated between the raceway surfaces of the inner and outer races 1, 3.
And a retainer 7 that holds each ball 5 at equal positions in the circumferential direction are the main constituent elements. In the present embodiment, the inner ring 1 is a fixed side member that is fitted and inserted into a shaft 38 (fixed shaft) in a vertical posture, and the outer ring 3 is a rotating side member that rolls on a guide rail 34 of the lateral stretching device.

The inner space of the bearing is a pair of seal members 9 arranged on both sides in the axial direction of the bearing, that is, on the upper and lower parts of the drawing (in FIG. 1, only the seal member arranged on the upper part is shown).
It is contactlessly sealed by. The seal member 9 has a disc shape, and its outer diameter end is fixed to a seal groove 1a formed on the inner circumference of the end portion of the outer ring 3. Groove 2 is formed in the shoulder of inner ring 1.
a is formed, and the seal member 9 is inserted into the groove 2a.
The labyrinth seal is formed by the inner diameter ends of the two facing each other through the minute seal gap 11. As the sealing member 9, as shown in the drawing, a metal core 9a is made of rubber 9
In addition to the rubber seal covered with b, a metal seal made of a metal plate can be used.

An oil sump 13 is formed in the seal member 9 of the seal member 9 on the upper side of the bearing. The oil sump 13 has a function of storing oil that has dropped from above, and is formed on the outer side surface 9c (a surface perpendicular to the bearing center) of the seal member 9. For example, as shown in FIG. 1, the oil sump portion 13 is partitioned and formed by providing an annular first protrusion 15 extending in the circumferential direction on the inner diameter portion of the side surface 9c of the seal member 9.

By forming such an oil reservoir 13, the upper guide rail 33 and the tenter clip 30 are formed.
Even if the oil dripped from the oil drops on the side surface 9c of the upper seal member 9 of the rolling bearing, this oil is retained in the oil sump 13 and does not flow into the bearing through the seal gap 11. Further, the oil retained in the oil reservoir 13 is shaken off toward the outer diameter side by the rotation of the seal member 9 during the rotation of the bearing, so that the function of the oil reservoir 13 is sequentially restored. Therefore, according to the present invention, it is possible to stably prevent oil from entering the inside of the bearing for a long period of time with a simple structure.

In the above description, the upper sealing member 9
The case where the oil sump 13 is formed only on the side surface 9c of the above is illustrated, but in addition to this, if a similar oil sump is formed on the side surface of the lower seal member (not shown), both seal members can be formed. Cost can be reduced by using the same shape.

FIG. 2 shows another embodiment of the present invention. An annular second projecting portion 17 extending in the circumferential direction is provided on the outer diameter side of the side surface 9c of the sealing member 9, and the second projecting portion 17 is provided. Part 1
7 is an example in which the inner diameter side and the outer diameter side of the oil sump 13 are sectioned and formed in the circumferential direction by the cooperation of 7 and the first protrusion 15. By forming such a second protrusion 17,
The oil that has moved to the outer diameter side due to the centrifugal force acts on the second protrusion 17
And is blown away in an oblique direction outside the radial direction (arrow A in the figure). Therefore, the oil does not stay in the mounting portion B of the seal member 9 or the like, and the effect of shaking off the oil can be enhanced. In order to obtain a sufficient swing-off effect, it is desirable that the inner diameter side surface of the second protrusion 17 (the surface defining the oil reservoir 13) be tapered so that the inner side of the bearing is reduced in diameter.

[0022]

According to the present invention, the oil dropped from above is held by the oil collecting portion on the side surface of the seal member, and is further blown to the outer diameter side by the rotation of the seal member. Therefore, it is possible to prevent the oil from flowing into the bearing from the seal portion between the seal member and the stationary member.

[Brief description of drawings]

FIG. 1 is a sectional view of a rolling bearing according to the present invention.

FIG. 2 is a cross-sectional view showing another embodiment.

FIG. 3 is a cross-sectional view of a transverse stretching device of a film stretching machine.

FIG. 4 is a sectional view of a conventional rolling bearing used in the transverse stretching device.

[Explanation of symbols] 1 Inner ring (fixed side member) 3 Outer ring (rotating side member) 5 balls (rolling elements) 7 cage 9 Seal member 11 Seal gap 13 Oil sump 15 First protrusion 17 Second protrusion

Claims (4)

[Claims] 1. A rolling bearing having a seal member which is mounted on a shaft in a vertical posture and seals the inside of the bearing at least at an upper portion, and one end of the seal member is fixed to a member on a rotating side. A rolling bearing characterized by having a reservoir portion formed therein. 2. A first protrusion is provided on a side surface of the seal member,
The rolling bearing according to claim 1, wherein the inner diameter side of the oil sump portion is partitioned in the circumferential direction by the first protrusion portion. 3. A second protrusion is provided on a side surface of the seal member,
The rolling bearing according to claim 2, wherein the outer diameter side of the oil sump is partitioned by the second protrusion in the circumferential direction. 4. A guide bearing which is rotatably supported by a guided member of a film stretching machine and rolls on a guide rail of the film stretching machine to guide the guided member along the guide rail. The rolling bearing according to claim 1.