JPS6220912A - Thrust bearing - Google Patents

Abstract

PURPOSE:To make improvements in load capacity so high, by housing a small ball between two discs and interposing a high viscous lubricant in between. CONSTITUTION:A bearing plate 1 consists of a ceramics disc where a lot of spiral grooves 2 are installed at both sides, and a sliding surface member 4 is installed in parallel with a sliding surface 3 of the bearing plate 1. In each center of opposite surfaces between the bearing plate 1 and the sliding surface member 4, there are provided with semispheric concave parts 7 and 8, and a small ball 6 is housed between these concave parts. In addition, in intervals between this small ball 6 and the bearing plate 1 and the sliding surface member 4, between these spiral grooves 2 of the bearing plate 1 and the sliding surface member 4 and between the sliding surface 3 of the bearing plate 1 and the sliding surface member 4, a high viscous lubricant 9 such like grease is sealed in.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] "Industrial Application Field" The present invention relates to a thrust bearing that is capable of forward and reverse rotation using dynamic pressure effects.

"Prior Art" As a conventional example, there is an invention disclosed in Japanese Patent Application No. 1G-/3 Dada No. 73. The invention provides a hard material having spiral grooves formed on the front surface in a direction that produces a dynamic pressure effect during forward rotation, and spiral grooves formed on the back surface in a direction that produces a hydrodynamic pressure effect during reverse rotation. A thrust bearing characterized by interposing an intermediate plate made of a material between opposing receiving plates, one of which rotates and the other of which is fixed, and is cheaper and compared to a tailing pad type floating thrust bearing. The power loss is less than /72.

In the above-mentioned known examples, the thrust bearings are used in lubricating and cooling fluids, such as thrust bearings in underwater motors, and tests on thrust bearings are conducted in liquids, and intermediate A member on the fixed side is provided to prevent the intermediate plate from moving in the radial direction so as not to come into contact with the outer periphery of the plate (hereinafter referred to as bearing plate).

"Problems to be Solved by the Invention" Since the above-mentioned thrust bearing is used by being immersed in liquid, it is necessary to construct a bearing chamber shaped like a container containing liquid, or to immerse it in liquid by constantly letting liquid flow down to the thrust bearing. It is necessary to do as follows.

In this way, it is practically difficult to equip a so-called dry structure electric motor with the thrust bearing of the above invention, and generally it must be used as a bearing device with a thrust bearing chamber, so the range of use is limited. Limited.

Further, in the thrust bearing of the above invention, when the bearing plate deviates in the radial direction, its outer periphery rubs against the member that prevents the radial deviation. Therefore, one horizontal machine is not used.

The object of the present invention is to provide a thrust bearing in which a bearing with spiral grooves on both sides is arranged so as to rub against a rotating side sliding surface member and a stationary side sliding surface member. It is an object of the present invention to provide a thrust bearing that can be applied to a bearing device and has a wide range of applications.

[Structure of the Invention] "Means for Solving the Problems" The present invention provides a ceramic disk having spiral grooves in opposite directions on both sides and a concave portion in the center of one or both sides, and one or both sides of the ceramic disk. A flat disk having a concave portion facing the concave portion of the ceramic disk is fitted together with a small ball accommodated across both concave portions of the ceramic disk and the flat disk, and the ceramic disk, the flat disk, and the small This is a thrust bearing with a high viscosity lubricant interposed between a ball, a ceramic disc, and a flat disc.

``Operation'' Since the ceramic disc and the flat disc are adsorbed by a high viscosity lubricant, they can be handled as a single unit thrust bearing. Once assembled, the ceramic disc or flat disc will not deviate in the radial direction. The bearing function is such that one side acts as a dynamic pressure fluid bearing due to the spiral groove, and the other side acts as an adsorption function, and either side slides in response to forward and reverse rotation.

"Example" Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view, and FIG. 1 is a plan view of FIG. 1.

/ is a bearing plate made of a ceramic disk with a large number of spiral grooves on both sides, and g is a bearing plate / with a sliding surface in contact with the sliding surface 3 of the bearing plate / through a liquid film of high viscosity lubricant. A disc-shaped sliding surface member with both sides precisely parallel, B is a hemispherical recess 7 provided at the center of the opposing surfaces of the bearing plate l and the sliding surface member group, respectively.
The small balls 9 housed in ゜g are between the small balls 6 and the bearing plate/and the sliding surface member DA, between the spiral groove of the bearing plate l and the sliding surface member DA, and between the sliding surface of the bearing plate l. A high viscosity lubricant such as grease is sealed between the moving surface 3 and the sliding surface member DA.

The depth of the spiral groove is 3 to 30 μm, and its width is narrower than the width of the sliding surface 3. Both surfaces of the sliding surface 3 and the sliding surface member 3 are finished with a highly accurate so-called mirror finish with a flatness/μm per surface roughness of about 0.3 μm. Normally, both sides of the sliding surface member Hiroshi are super-finished, but depending on the application, only one side on the side in contact with the bearing plate 1 may be super-finished.

Recess 7. The gap between t and the small ball 6 is such that when the bearing plate 1 and the sliding surface member are in solid contact, there is a very small gap or they are in contact with each other.

The material for the bearing plate should be one that has good thermal conductivity, one that can ensure surface processing accuracy, and one that has high compressive strength. Ceramic materials, such as silicon carbide (Sin!), are recommended. , silicon nitride 5i5
N4 is used, and SIC porous materials are preferred, but dense materials may also be used. The material of the sliding surface member is SiC, alumina ceramics, cemented carbide, high lead bronze, ordinary cast iron, 73
% chromium stainless steel, etc., and dense or porous materials are used. The small ball 6 is made of SiO and impregnated with a highly viscous lubricant, but it may also be a steel ball made of bearing steel.

Porous bodies may be used for the bearing plate/and the small balls 6,
The combinations of porous bodies and dense bodies for the above materials are as follows.

Combination A B C bearing plate/
Porous body Dense body Dense body sliding surface member y Dense body Dense body Dense body small sphere 6
Dense body Porous body Dense body In this thrust bearing, the liquid film on the sliding surface is as small as about 1.!μm when the surface pressure is 0Q(ν).

Therefore, the total amount of lubricating fluid in the spiral groove, the small ball 6, and the area around the small ball 6 is as small as 0.00 jcc, where the outer diameter of the bearing plate 1 is SO mm.

In the case of combination B above, the outer diameter! The small ball 6 used for the bearing plate l of rOmiIJ meter is S1C with a diameter of commimeter and a porosity of bo%.

FIG. 3 shows an example of application using the thrust bearing of the present invention. The sliding surface member DA is adhesively fixed to a leveling block 13 in which the hemispherical tip of an adjustment screw L/ screwed into the fixed portion is floatingly supported in contact with the concave surface /J at its center. A detent pin /Q provided at the fixed portion is loosely fitted into a hole provided in the axial direction of the end surface near the outer periphery of the leveling block 13. The opposite surface that does not contact the sliding surface of the bearing plate / is connected to the rotating shaft /j with the key 16.
The high viscosity lubricant 1 is in contact with the rotary side receiving plate 17 which is press-fitted and fixed via the high viscosity lubricant 1. This high viscosity lubricant is applied during assembly, or is obtained by caulking the bearing plate l in advance and covering it with a synthetic resin coating, and then removing the coating during assembly. Since the rotating side receiving plate 7 contacts the bearing plate 1 as a sliding surface member, its material is the same as that of the sliding surface member DA, and the sliding surface is super-finished like the sliding surface member DA.

When the rotating shaft 13 rotates in the counterclockwise direction indicated by the arrow in FIG. It becomes high at the end, forming a hydrodynamic bearing. bearing plate l
Between the sliding surface member DA and the bearing plate 1, the bearing plate 1 is energized to be rotated counterclockwise, and the lubricant 1 is energized toward the outer periphery, but vacuum pressure is immediately generated and the bearing plate 1 is rotated counterclockwise. Video parts are attracted.

Contrary to the above, when the rotating shaft /3 rotates clockwise, the bearing plate /
The lubricant between the bearing plate L and the rotating side receiving plate L is urged toward the outer periphery by the spiral groove, and the bearing plate L and the rotating side receiving plate L are immediately vacuum-adsorbed, and the bearing plate L is attached to the rotating side receiving plate L. It rotates clockwise together with 17. As the bearing plate l rotates in the clockwise direction, the lubricant 9 between the bearing plate l and the sliding surface member 9 is directed toward the center by the action of the spiral groove, and a high-pressure liquid flow is generated in the center, and the bearing plate l moves toward the sliding surface. It rotates while bearing a thrust load while being in fluid lubrication with the member.

If the thrust load on the rotating shaft 13 is directed downward rather than upward in FIG. Even if the bearing plate/and sliding surface member da,
Since a suction force acts between the bearing plate 1 and the rotating side bearing plate 17, it can withstand thrust loads in a direction opposite to the main thrust direction.

The forward and reverse special number ζ bearing plate of the rotating shaft /3 becomes unstable in the radial direction, but in this case the small ball 6 and the recess 7. ff J The center is maintained.

Figure 7 shows a recess t on both sides of the bearing plate l with small balls 6 interposed therebetween.
FIG. FIG. 5 shows a longitudinal sectional view of an embodiment in which such an embodiment is provided between the rotating shaft end and the stationary side. The sliding surface member may be disposed on either the rotating shaft or the fixed shaft side.

The upper sliding surface member DA is adhesively fixed to the thrust disk/1 which is fixed to the end of the rotating shaft IS via a key 16. The other configurations are the same as in FIG. 3. In this embodiment, the thrust disk /1 and the upper sliding surface member abutment correspond to the rotating side bearing plate 17, but the sliding surface member 1.4' on both sides of the bearing plate l is radially moved by the small balls 6, 6. can move and has a thrust disk/1. Since it is fixed to the leveling block 13, it becomes a sliding bearing between the small ball 6 and the recesses 7 and 1.
Although the load capacity is small, it can carry a moderate radial load.

Experiments have shown that in both the embodiments shown in Figures 3 and 5, when the forward and reverse rotations were performed 10,000 times without stopping, there was no damage to the sliding surfaces. The lubricant grease was not reduced at all. The above experiment was also conducted in the air and underwater. However, when used underwater, it is necessary to seal in a water-insoluble lubricant. Further, in an experiment similar to the above in a slurry liquid, no penetration of the slurry into the spaces between the sliding surfaces was observed.

In FIGS. 1 and 9, the bearing plate l and the sliding surface member l are not aligned along the sliding surface, and even if you try to do so, the bearing plate l and the sliding surface member l are not aligned along the sliding surface.
The sliding surface member 1 cannot be moved, and even if the bearing plate 1 and the sliding surface member 1 are pulled in the axial direction, they remain in a vacuum suction state, and can withstand a considerable thrust load in the direction of separating them. Of course, it won't separate during handling, and the lubricating oil film will also be removed! Since the size is on the order of μm, there is no practical problem with the intrusion of foreign matter.

In the example, one bearing plate and one sliding surface member are stacked, and one bearing plate and sliding surface members are stacked on both sides. When the sliding surface members of 2 are stacked with recesses on both sides of the center for the small balls to be placed, the bearing plates and the sliding surface members overlap alternately, creating a multi-plate thrust bearing. It becomes an element member of.

From this point of view, it is desirable from the standpoint of flexibility to provide recesses into which the small balls can fit on both surfaces of the bearing plate and the sliding surface member.

〔Effect of the invention〕

The present invention provides spiral grooves in opposite directions on both sides,
A ceramic disc having a recess in the center of one or both sides, and a flat disc having a recess opposite to the recess in the ceramic disc on one or both sides, are combined over both the recesses of the ceramic disc and the flat disc. Since the thrust bearing contains small balls and has a high viscosity lubricant interposed between the ceramic disc and the flat disc, and between the small ball and the ceramic disc and the flat disc, the bearing plate and the sliding surface member are Since they are in an adsorbed state and do not come apart even when handled, by supplying these components in an assembled state, they can be handled as if they were sealed ball bearings.

Therefore, there is no need to design the thrust bearing device with special consideration for lubrication, and it can be used both in the air and in liquid. The load capacity is extremely large (it has a considerable load capacity even for thrust loads in the direction of separating the bearing plate and the sliding surface member.Friction loss is small, and no cooling means is required.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of an embodiment of the present invention, Fig. 1 is a plan view of a bearing plate, Fig. 3 is a longitudinal sectional view showing an application example of Fig. 1, and Fig. 7
The figure is a longitudinal sectional view of another embodiment, and FIG. S is a longitudinal sectional view showing an application example of FIG. /0. Bearing plate 3. Spiral groove. . Sliding surface da...Sliding surface member 6...Small ball 7. t...Concave D...High viscosity lubricant //...Adjustment screw /K--Concave /, 7--Leveling block /
4'...Stopping pin /j...Rotation axis /6...Key
17...Rotating side receiving plate 1g...Thrust disk. Patent applicant Ebara Research Institute, Ltd. Ebara Corporation

Claims (1)

[Claims] 1. A ceramic disc with spiral grooves in opposite directions on both sides and a recess in the center of one or both sides, and a flat disc with a recess opposite to the recess of the ceramic disc on one or both sides. The small balls are accommodated in the recesses of the ceramic disc and the flat disc, and high viscosity lubrication is applied between the ceramic disc and the flat disc, the small ball and the ceramic disc, and the flat disc. Thrust bearing with agent in between.