JPS61223320A - Thrust bearing - Google Patents

Abstract

PURPOSE:To improve the erosion resistance of a thrust bearing part by making the slidable surface which slides in opposition to a spiral groove from martensite stainless steel. CONSTITUTION:Water is introduced into the center part along a spiral groove from the peripheral part of a plate 10 by the upper receiving plate 12 as the slidable member which rolls in contact with the spiral groove, and a dynamic pressure effect is generated between the plate 10 and the upper receiving plate 12. Since the plate 10 is made ceramic material, and the upper receiving plate 12 is made of martensite stainless steel, the erosion resistance of the thrust bearing pat can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thrust bearing that utilizes a dynamic pressure effect and is used in pumps, ice motors, and the like.

[Prior art]

An example of a conventional thrust bearing of this type is shown in FIG. Third
The figure shows a tilting paddle type thrust bearing of an underwater motor, in which a disk 3 is fixed to an upper support 2 that rotates together with a rotating shaft 1, and a fixed shaft 4 is placed opposite the disk 3.
A pad 8 is attached so as not to rotate on the upper part of a lower support body 7 which is supported by a spherical surface 5 and engaged with a bottle 6 so as not to rotate.

In addition, as other conventional techniques, for example, Japanese Patent Publication No. 41-121
An example is the spiral thrust bearing disclosed in Japanese Patent No. 21.

[Problem that the invention seeks to solve]

However, in the conventional device as described above, for example in the one shown in FIG. 3, when unevenness occurs on both surfaces of the disk 3 and the pad 8 that slide against each other due to wear during use or due to the intrusion of foreign matter, the unevenness may occur. Heat is generated in the
This heat tends to cause materials to stick together, which is called pseudo-wear.Also, a lubricant with high viscosity is required to exert a large lubricating effect, and the sealing and cooling methods of this lubricant, as well as the deterioration of the lubricant, tend to occur. There is a problem with hot spring 1.
However, there were drawbacks such as the inability to use high-temperature liquids such as geothermal water. Also, in order to increase the thrust load capacity, a larger one was required.

Furthermore, the method disclosed in Japanese Patent Publication No. 41-12121 has the following problems. That is, when driving a pump or submersible motor, the impeller shaft may be rotated in the opposite direction due to a wiring error. In the case of a spindle-type pump, etc., the bearing may rotate with the thrust load of its own weight being applied to the bearing.

The above-mentioned bearing has the disadvantage that, depending on the operating point, if the shaft rotates in the opposite direction, no dynamic pressure is generated at all, and depending on the material, seizure may occur.

In addition, as a thrust bearing that eliminates these drawbacks, there is a ceramic spiral group bearing that was previously proposed by the inventor of the present application, but the bearing part is not suitable for use in river water, seawater, groundwater, geothermal water, or brush water. If the sliding surface facing the spiral grooved ceramic surface is made of FC (cast iron), corrosion will occur, or if the sliding surface is immersed in water for a long period of time, such as austite stainless steel T1M (
SUS304) does not cause corrosion, but it has drawbacks such as low thrust load capacity (Japanese Patent Application No. 59-2210).
No. 78).

The present invention solves the above-mentioned disadvantages of the conventional ones, has a simple and small-sized configuration, has a large thrust load capacity, and has low wear loss. The purpose of the present invention is to provide a thrust bearing that is free from corrosion even when immersed in so-called water such as water or a corrosive aqueous solution, and is free from abrasion accidents.

A second object of the present invention is to provide a thrust bearing that has a large thrust load capacity V regardless of whether the shaft rotates in the normal or reverse direction.

[Means for solving problems]

As a means of solving the above-mentioned problems, the present invention provides a sliding member made of ceramic material having spiral grooves formed on its surface, and martensitic stainless steel having a sliding portion facing the surface on which the spiral grooves are formed. and a moving member;
It consists of a surface on which the spiral groove is formed and the sliding surface. A thrust bearing characterized in that the sliding part is supported so as to perform a relative rotational movement in a state submerged in water, and the thrust is supported by the dynamic pressure generated by the relative rotational movement, and the front and back surfaces thereof are , a ceramic disk in which spiral grooves are formed in the same direction on the projection plane of the axial gyrus, and two martensitic stainless steels having opposing sliding surfaces on the front and back surfaces of the ceramic disk, respectively. and a sliding member consisting of the ceramic disk, and the two sliding parts consisting of the front and back surfaces of the ceramic disk and the two sliding surfaces facing the ceramic disk are subjected to relative rotational movement while immersed in water. The relative figure 1
．． The present invention provides a thrust bearing characterized in that it is configured to support thrust by dynamic pressure generated by rolling motion.

[Effect].

In the thrust bearing of the present invention, a sliding portion is formed by the surface of the ceramic on which the spiral groove is formed and the surface facing this, but since this sliding portion is submerged in water, It can slide with small power loss even under extremely large thrust loads.

In addition, in the second invention, spiral grooves are formed in the same direction in the axial projection plane on the front and back surfaces of the ceramic interposed between the rotating shaft and the fixed member, and the spiral grooves are opposite to each other. A sliding part (however, one becomes a fixed part depending on the direction of rotation of the shaft) is formed between the shaft and the surface, so that even if the rotating shaft rotates in the forward or reverse direction,
A sliding part with extremely low sliding resistance is formed on one side of the ceramic disc, and a force that fixes the ceramic disc is generated on the other side, so that it can be rotated in either the forward or reverse direction. Also, an extremely good sliding portion is formed.

In the present invention, the number of spiral grooves formed on the surface of the ceramic is an arbitrary integer of 2 or more, but in order to generate high dynamic pressure, it is desirable to have 10 or more, and the number of spiral grooves formed on the surface of the ceramic is The pressure tends to be saturated when the number of spiral grooves is 30 or more. Also, the shape of this spiral groove is shown in polar coordinates (r・θ) as r = 1,
661va11g It is preferable to use the one shown above, but it is not strictly necessary to go with this.

Furthermore, here rl: inner diameter, α: Angle between the sliding direction and the tangential direction of the groove.

〔Example〕

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, in which an upper support plate 12 is fixed via a filler to an upper support 2 that rotates together with a rotating shaft 1, and a fixed shaft 4 A lower support plate 13 is fixed to the lower support body 7 supported by the spherical surface 5 via a filler, and a plate 10 which is a ceramic member is further fixed. Spiral grooves are formed on the surface of the ceramic temporary 10, and these are housed in a bearing chamber 14 filled with water. Further, 6 is a pin.

As the front view of the ceramic plate 10 is shown in FIG. 2, a spiral groove 11 (black part in the figure) is provided on the surface of the ceramic plate 10. Water is removed from the plate 10 by the upper receiving plate 12 as a sliding member having a sliding surface that rotates in contact with the groove 11.
The plate 10 is guided from the periphery of the board 10 along the spiral 1s11 to the central part (the black part in the figure forms a concave part).
and the upper receiving plate 12 in a direction that produces a dynamic pressure effect.

In this embodiment, the ceramic material constituting the plate 10 is S i C,, S i 3 N4, and the upper receiving plate 12 is made of martensitic stainless steel @ (
JIS standard 5US420J2) is used.

Although this ceramic material has excellent corrosion resistance, it has poor workability, so it is not easy to process extremely shallow spiral grooves of 3 to 50 μm on its surface. The surface of the workpiece is covered with a spiral resin mask of a predetermined shape, and then a spiral groove is formed in an extremely short time using a shot blasting method in which fine alumina abrasive material is sprayed onto the resin mask. I can do it. Laser processing is also possible. The spiral-shaped resin mask mentioned above is made by exposing and curing polyester-based liquid photosensitive resin with ultraviolet light.
As for the manufacturing method, first, a negative film with spiral grooves is created, this is placed on a glass plate, a transparent cover film is placed on top of this, and a photosensitive liquid resin is poured. Further, a base film is further laminated on top of this resin using a roll.

Next, the mask is exposed to ultraviolet light for a few seconds, passed through a negative film, and the exposed area of the resin hardens, creating a resin mask with the same spiral groove shape as the film.

The resin mask used in this bearing consists of a two-layer base film, an adhesive resin with a spiral groove pattern, and a protective paper. When performing shot processing, the protective paper is removed and pasted onto the surface of the workpiece, and one layer of the base film is peeled off.

The ceramic plate used here was a pressureless sintered type 5iC (silicon carbide) with a thickness of 2 mm, S i 3 N4
(Silicon nitride), a spiral groove with a depth of 10 μm was machined using the shot blasting described above.

According to this embodiment, when the rotating shaft 1 is rotated with a load applied to it, the spiral groove 11 on the surface of the plate 100 becomes
Dynamic pressure is generated as water is forcibly moved from the periphery toward the center, and a liquid film of the required thickness is formed between the opposing surfaces to support the thrust load. Since the sliding resistance at this time is extremely small, the amount of heat generated due to power loss is extremely small. Therefore, even if the plate 10 is bonded to the receiving plate of the housing, there is no fear of cracking due to the difference in thermal expansion, and the plate 10 can also be used as a high-temperature bearing. Moreover, on the contrary, even if the ceramic viIO is fixed on the rotating side, the effect is exactly the same.

In addition, in this embodiment, since the spiral groove 11 of the ceramic plate 10 exhibits sufficient bearing capacity with a depth of 3 to 50 II m, the material ceramic,
Tux also has an economical wall thickness, for example 1 to 2 mm for SiC.
It is convenient for high-temperature use because it can be manufactured at low cost as described above, and there is no fear of cracking due to the difference in thermal expansion caused by adhesion.

FIG. 4 is a schematic diagram of the thrust bearing testing apparatus, in which test bearing members 2jA and 21B forming the thrust bearing 21 are shown.
One bearing 21A is connected to a variable speed motor (10 to 5000
r p m) 24 via a pulley 25; The other bearing 21B is attached to the end of the thrust shaft 27 via a hydraulic cylinder (~10000k100O0) and a load cell 30. In the figure, 22 is a bearing, 25 is a pulley, 26 is a torque meter, 2
9 indicates a hydraulic pump.

Table 1 shows the results of testing the thrust bearing of this example in water using the thrust bearing testing apparatus shown in FIG. Illustrate.

Table 1. Here, the limit bearing surface pressure is the load at 4 points during seizure divided by the bearing area. Is it clear from Table 1? β to
The combination of -3iC and 5US42QJ2 gave a greater result than the combination of β-8iC and Fe12. Moreover, the former has excellent corrosion resistance even when wet in ice (1) Underwater binding is desirable.

In Table 1, the outer diameter of the ceramic deck is 86 mm, and the rotation speed Lj 2. , Q, 0(l r p m
T: Yes.

Further, the surface roughness of the spiral grooves 1 and 6 to 8 .mu.m is 0.3 .mu.m or less by lapping.

Further, as an example corresponding to the second aspect of the present invention, a similar test was conducted using the same as shown in FIG.

That is, in FIG. 5, the ceramic plate 10 of the embodiment shown in FIG. Is it true that the spiral guiding sound is formed now, and therefore the front and back sides of the female Rami and Soku board 1.0 are both 1.0 and 1.0? In addition, the directions of the spirals are the same in the axial projection plane. , .

In addition, 15 is a drill 1 when the rotating direction of the rotating shaft is reversed.
0 force 5 receiving plate 12. ．． ．． This is a protrusion provided to prevent it from jumping out from between 13.

In this case, no matter which direction the rotating shaft rotated, the same sliding characteristics as before were exhibited.

[Blooming effect]

, In the present invention, river water, seawater, Blackwater,
For a spiral group type thrust bearing that operates s7 immersed in ground water, geothermal water (corrosive aqueous solution, etc.), a ceramic plate with a spiral groove formed thereon is used, and the ceramic plate is slid facing the spiral groove. Since the thrust bearing is constructed using martensitic stainless steel as the material for the sliding surface that moves, the corrosion resistance of the Ni-thrust bearing part is improved, and its sliding characteristics (limit load surface pressure) are improved. Improved. When the thrust bearing of the present invention is applied to an underwater motor or pump, the structure becomes simple and compact, and it can be said to be extremely useful in practice.

In addition, by providing spiral grooves on both sides of the ceramic disc that are oriented in the same direction in the axial projection plane and forming sliding surfaces on each side, a large thrust can be generated whether the shaft rotates forward or backward. It has a large capacity and can exhibit excellent sliding properties.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a plan view showing a ceramic spiral plate used therein, and Fig. 3 is a sectional view of a conventional tilting path type thrust bearing. FIG. 4 is a schematic diagram showing a test apparatus according to the present invention, and FIG. 5 is a sectional view of another embodiment. 1-rotating shaft, 2-upper support, 3-disc, 4-fixed shaft, 5-spherical surface, 6-pin, 7-lower support, 8-hasod, ]〇-plate, 11-spiral groove, 12 -1 part receiving plate, 13-lower receiving plate, 14-bearing chamber, 15-=-protrusion, 2
1.-Thrust bearing, 21A, 21B---Bearing member,
22-bearing, 23-rotating shaft, 24-variable speed motor, 25
-Pulley, 26-l-Lux meter, 27-thrust shaft, 28
-Hydraulic cylinder, 29-Hydraulic pump, 30-Low 1-''
cell. Patent Applicant: Ebara Research Institute, Inc. Patent Applicant: Ebara Corporation, Representative Patent Attorney Takashi
Masayuki Ki, Patent Attorney, Pharmacist
Minoru, Patent Attorney 1) Takatsugu, Part 4) Figure 4

Claims (1)

[Scope of Claims] 1. A ceramic member having spiral grooves formed on its surface, and a sliding member made of martensitic stainless steel having a sliding surface facing the surface forming the spiral grooves, A sliding part consisting of a surface formed with a spiral groove and the sliding surface is supported so as to perform relative rotational movement while submerged in water, and thrust is supported by dynamic pressure generated by the relative rotational movement. A thrust bearing characterized by being configured as follows. 2. A ceramic disc with spiral grooves formed in the same direction on the axial projection plane on the front and back surfaces, and two sliding slides having opposing sliding surfaces on the front and back surfaces of the ceramic disc, respectively. and a moving member, and performs a relative rotational movement in a state in which two sliding parts consisting of the front and back surfaces of the ceramic disc and the two sliding surfaces opposing these are immersed in water. What is claimed is: 1. A thrust bearing characterized in that the thrust bearing is configured to support the thrust by dynamic pressure generated by the relative rotational motion.