JPH08303472A - Grease drop preventing device - Google Patents

Abstract

PURPOSE: To provide a grease drop preventing device having the small leakage of grease by a simple and inexpensive means. CONSTITUTION: A grease drop preventing device is provided with a vertical two-way thrust bearing 8 attached on a vertical shaft 4, a bearing casing 2 provided with the space for housing the thrust bearing, a seal ring 15 mounted between the lower surface of the thrust bearing and the bearing supporting surface 12a of the bearing casing so as to cover the grease space in the bearing, and an elastic bouncing member 17 mounted between the seal ring and the bearing supporting surface, and for energizing the seal ring upward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grease drop preventing method in a vertical thrust bearing device.

[0002]

2. Description of the Related Art FIG. 4 shows a bearing device for supporting a vertical shaft 30 which may be subject to axial thrust from either the upper or lower direction. The bearing casing 3 has a through hole.
The bidirectional thrust bearing 32 is housed in the housing 1, and the cover 33, which is bolted to the casing, holds the bidirectional thrust bearing 32. The oil seal 3 is provided to prevent the lubricating grease inside the thrust bearing 32 from dropping.
4 is used.

Further, in the above conventional bearing device, the shaft 3
In order to suppress the movement of 0 in the vertical direction, it is necessary to adjust the related dimensions so as to eliminate the gap A between the upper surface of the thrust bearing 32 and the cover 33. However, the gap in part A is
2. The adjustment is difficult because it depends on the processing accuracy of the related dimensions of the bearing casing 31 and the cover 33. Casing 3
Since it is not preferable in terms of strength to form a gap between B and the cover 1 between the cover 1 and the cover 32, in reality, the dimensions and the processing accuracy are set so that a minute gap that can be practically allowed is formed in A.

[0004]

However, in the prior art as described above, since the oil seal is in contact with the rotating shaft, the shaft side corresponding portion may be worn and cause grease leakage. However, there was a problem that it was necessary to replenish grease in a timely manner. In order to prevent abrasion of the shaft, there is a method of subjecting the shaft sliding portion to a surface hardening treatment or attaching a replaceable sleeve, but the cost increase cannot be denied. The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a grease drop prevention device with less grease leakage by a simple and inexpensive means.

[0005]

According to a first aspect of the present invention, there is provided a vertical bidirectional thrust bearing mounted on a vertical shaft, a bearing casing having a space for accommodating the thrust bearing, and a lower surface of the thrust bearing. And a bearing ring between the bearing casing and the bearing support surface of the bearing casing so as to cover the grease space in the bearing, and a bullet that is attached between the seal ring and the bearing support surface to urge the seal ring upward. It is a grease fall prevention device characterized by having a starting member. The invention according to claim 2 is the grease drop prevention device according to claim 1, wherein the elastic member uses an elastic force based on elastic deformation of a metal.

According to a third aspect of the invention, there is provided the grease drop prevention device according to the first or second aspect, wherein the elastic member is a metal ring deformed in the axial direction. According to a fourth aspect of the present invention, the seal ring includes a flat plate-shaped edge portion that is sandwiched between a lower surface of the outer ring of the thrust bearing and a bearing support surface of a bearing casing.
The grease drop prevention device according to any one of claims 1 to 3, further comprising an inner edge portion that faces a lower surface of the inner ring of the thrust bearing with a minute gap therebetween. The invention according to claim 5 is the grease drop prevention device according to any one of claims 1 to 4, characterized in that the seal ring is provided with a concave portion for accumulating grease on the upper surface thereof.

[0007]

According to the first aspect of the invention, the seal ring is mounted between the lower surface of the thrust bearing and the bearing support surface of the bearing casing so as to cover the grease space in the bearing, and prevents the grease from falling. When an upward thrust is applied to the shaft, an elastic member mounted between the seal ring and the bearing support surface urges the seal ring upward to bring it into close contact with the bearing, thus preventing grease leakage. In the invention according to claim 2, since the elastic member urges the seal ring by the elastic force based on the elastic deformation of the metal, a stable structure having high durability and strength can be obtained with a simple structure and an inexpensive material. be able to.

According to the third aspect of the invention, the metal ring is deformed in the axial direction by wavy or twisting.
By pressing and deforming the lower surface of the bearing, a force that urges the bearing upward is generated. In the invention according to claim 4, the seal ring is firmly sandwiched at its edge portion between the lower surface of the outer ring of the thrust bearing and the bearing supporting surface of the bearing casing, and the inner edge portion is the inner portion of the thrust bearing. Grease leakage is prevented by facing the lower surface of the ring with a minute gap. According to the fifth aspect of the invention, the grease that has fallen is stored in the concave portion on the upper surface of the seal ring.

[0009]

Embodiments of the present invention will be described below with reference to FIGS.
Will be described with reference to. FIG. 1 is a sectional view of the bearing device of the present invention. Here, a cylindrical recess 1 is formed in a part of the casing of, for example, a pump or a motor to form a bearing casing 2. A through hole 5 for inserting the shaft 4 is formed in the bottom 3 of the recess 1, and the upper side of the recess 1 is covered with a cover 6 fixed to the upper surface of the bearing casing 2 by bolts.

A step 7 having a small diameter on the lower side is formed on the shaft 4, and an inner ring 9 of a bidirectional thrust bearing (rolling bearing) 8 is fitted around the small diameter portion. The inner ring 9 is fastened by a fastening member 11 via a pressing ring 10 and is sandwiched between the inner ring 9 and the step 7. The thrust bearing 8 is mounted in the space above the step portions 12a and 12b formed in the middle of the recess 1 as a whole. A ring-shaped protrusion 13 is formed on the lower surface of the cover 6, and the lower surface of the protrusion 13 and the outer ring 1 of the bearing are formed.
A small gap is allowed between the upper surfaces of 4 by design.

In this bearing device, the oil seal as shown in FIG. 4 is not adopted, but the grease drop prevention device of the present invention is installed instead. In other words, this grease drop prevention device includes a metal seal ring 15 in contact with the lower surface of the thrust bearing 8 and a bearing seat 16 below the metal seal ring 15.
And the elastic member 17 on the lower side thereof.

As shown in FIG. 2, the metallic seal ring 15 is formed with a cylindrical body 18 through which the pressing ring 10 is inserted, a concave portion 19 serving as a grease reservoir is formed on the outer side thereof, and the outer side thereof is It is a flat plate ring-shaped edge portion 20 that contacts the lower surface of the outer ring 14 of the bearing. The bearing seat 16 has its upper surface in contact with the edge portion 20 of the seal ring 15,
The lower surface is in contact with the first step surface 12a of the recess 1. The elastic member 17 is, for example, a ring with a notch 21 that has undergone a corrugated deformation process as shown in FIG. 3, and is in contact with the lower surface of the bearing seat 16 and the second step surface 12b of the recess 1. The height of the step is smaller than the unloaded thickness of the elastic member 17,
Therefore, normally, thrust such as gravity applied to the shaft 4 is received via the bearing seat 16 and compressed. In addition to this, a coil spring, a disc spring, or the like can be applied as the elastic member. The bearing seat 16 is an auxiliary component for transmitting the repulsive force of the elastic member 17 to the seal ring 15 and the thrust bearing 8.

The operation of the bearing device having the above structure will be described. As described above, between the casing 2 and the cover 6 B
Since it is not preferable in terms of strength to form a gap in A, the dimensions are set so that a minute gap can be formed in A. When a downward load is applied to the shaft 4, the seal ring 15 receives a force from the lower surface of the outer ring 14 of the thrust bearing 8 at its edge portion 20, and the first step surface 1 through the bearing seat 16.
It is pressed against 2a and fixed.

The cylindrical body 18 of the seal ring 15 has an upper end on the lower surface of the inner ring 9 and an inner peripheral surface on the pressing ring 10.
Facing the outer peripheral surface of each with a small gap,
It slides as the shaft 4 rotates. The grease that falls from the inside of the bearing 8 collects in the grease reservoir 19, and this gap prevents further dropping.

When an upward thrust is applied to the shaft 4, the thrust bearing 8 moves upward until its outer ring 14 contacts the ridge 13 of the cover 6. Here, the elastic member 17
Since the bearing seat 16 and the seal ring 15 are urged upward by the elastic force of the seal ring 15, the seal ring 15 is always brought into close contact with the lower surface of the thrust bearing 8, and thus the gap between the seal ring 15 and the thrust bearing 8 is increased. Prevents grease from leaking.

[0016]

According to the present invention, no matter which direction the thrust is applied to the vertical shaft, the elastic member mounted between the seal ring and the bearing support surface urges the seal ring upward, Keep the seal ring in close contact with the bearing to prevent grease leakage. Therefore, unlike the case of the conventional oil seal, the shaft is not worn, grease is not leaked and dropped into the bearing casing, and it is not necessary to replenish the grease.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a bearing device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of main components of the bearing device of the present invention.

3 (a) is a plan view and FIG. 3 (b) is a sectional view of main components of the bearing device of the present invention.

FIG. 4 is a cross-sectional view showing a conventional bearing device.

[Explanation of symbols]

 2 Bearing casing 4 Vertical axis 8 Thrust bearing 9 Inner ring 12a Bearing support surface (step) 14 Outer ring 15 Seal ring 17 Repulsive member 18 Cylindrical body 19 Recess 20 Edge

Claims (5)

[Claims] 1. A vertical bidirectional thrust bearing attached to a vertical shaft, a bearing casing having a space for accommodating the thrust bearing, and a bearing inside the bearing between a lower surface of the thrust bearing and a bearing support surface of the bearing casing. Preventing grease drop, comprising: a seal ring mounted so as to cover the grease space; and an elastic member mounted between the seal ring and the bearing support surface to urge the seal ring upward. apparatus. 2. The grease drop prevention device according to claim 1, wherein the elastic member uses an elastic force based on elastic deformation of metal. 3. The elastic member is formed by axially deforming a metal ring.
The grease drop prevention device described in. 4. The seal ring comprises a flat plate-shaped edge portion sandwiched between a lower surface of an outer ring of the thrust bearing and a bearing support surface of a bearing casing, and a minute gap between a lower surface of an inner ring of the thrust bearing. The grease drop prevention device according to any one of claims 1 to 3, further comprising inner edge portions facing each other. 5. The grease drop prevention device according to claim 1, wherein the seal ring has a recess formed in an upper surface thereof for accumulating grease.