JP5270329B2 - Thrust slide bearing and pump equipped with the thrust slide bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thrust sliding bearing which improves the contact condition of a slide-contacting surface, and reduces partial wear. <P>SOLUTION: The thrust sliding bearing is equipped with a rotating-side slide-contacting member 30 with a slide-contacting surface, a fixing side slide-contacting member 31 with a slide-contacting surface, a rotating side deforming member 40 contacting an end surface opposite to the slide-contacting surface of the rotating-side slide-contacting member 30, and a fixing side deforming member 41 contacting an end surface opposite to the slide-contacting surface of the fixing side slide-contacting member 31. When a thrust load is applied to the rotating-side slide-contacting member 30 and fixing-side slide-contacting member 31, the rotating-side deforming member 40 and fixing-side deforming member 41 are so deformed as to cause the slide-contacting surfaces to come into surface contact with each other. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a thrust slide bearing that receives an axial load, and a pump including the thrust slide bearing.

  The pump pressurizes the liquid by rotating the impeller and discharges the liquid from the discharge port. The impeller is rotationally driven by a driving source such as a motor through a shaft rotatably supported by a bearing. Generally, the bearing used for the pump includes a radial bearing that supports a radial load and a thrust bearing that supports a thrust load. As an example of the bearing, there is a sliding bearing using the dynamic pressure of the liquid sucked by the relative rotation of the bearing sliding contact surface accompanying the rotation of the impeller.

  FIG. 1 is a cross-sectional view schematically showing a thrust slide bearing. As shown in FIG. 1, the thrust sliding bearing has a rotation side sliding contact member 51 and a fixed side sliding contact member 52. The fixed-side slidable contact member 52 is held by a fixed base 55, while the rotation-side slidable contact member 51 is fixed to a rotating base 56 that rotates integrally with the shaft. 2A is a plan view showing the fixed-side sliding contact member 52, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A. As shown in FIG. 2A, a spiral groove 57 for generating a dynamic pressure of the liquid is formed on the sliding contact surface of the fixed-side sliding contact member 52. The spiral groove 57 is for facilitating the supply of the liquid used for lubrication to the sliding contact surface, and has a depth of about 10 μm. The spiral groove 57 is generally formed by laser processing.

  The sliding members 51 and 52 are generally formed of a ceramic such as SiC. However, when the liquid handled by the pump is ultrapure water, the sliding members 51 and 52 are corroded, and the life of the bearing is extremely shortened. Thus, when such a handling liquid is used, it has been proposed to improve durability by coating the sliding contact surfaces of the sliding contact members 51 and 52 with polycrystalline diamond (for example, Patent Document 1). reference). The polycrystalline diamond film is formed as a film having a thickness of several μm to several tens of μm because it is easily peeled off when the film thickness is too thin and is easily cracked when the film is too thick.

  By the way, when a thrust load is applied to the rotation side sliding contact member 51 and the fixed side sliding contact member 52, these sliding contact members 51 and 52 are finally restrained by the holding surfaces of the rotation base 56 and the fixed base 55, respectively. Is done. For this reason, depending on the work accuracy and the assembly accuracy, the sliding contact surfaces of the rotation-side sliding contact member 51 and the fixed-side sliding contact member 52 do not contact each other correctly, and one end portion contacts the other part. It becomes only. FIG. 3 is an exaggerated representation of the state in which the sliding contact surface is tilted.

  When the slidable contact surfaces are inclined with respect to each other in this manner, the contact point (actually, the slidable contact surface rotates relatively, so that one of the circles has a radius from the rotation center of the bearing to the contact point). The load is concentrated on the sliding surface and the sliding contact surface is unevenly worn. Since the diamond coating is thin, the ceramic of the base material is exposed earlier than expected due to uneven wear. And the exposed part contacts liquid (ultra pure water), the sliding contact members 51 and 52 corrode, and as a result, the lifetime of a bearing will become short. Such problems due to uneven wear can occur not only in the diamond coating but also in other coatings. Furthermore, even for a bearing without a coating, it is a problem that affects the reduction of the bearing life.

  In addition, when a diamond film is formed on the sliding contact surface in which the spiral groove 57 (see FIG. 2A) is formed, the sliding contact surface is corroded by ultrapure water despite the presence of the diamond coating. The phenomenon of cracking and peeling frequently occurs.

JP 2006-275286 A WO2008 / 133197A1

The present invention has been made in view of the above-described problems, and a first object thereof is to provide a thrust sliding bearing that improves the contact state of the sliding contact surface and reduces uneven wear.
It is a second object of the present invention to provide a thrust slide bearing having a polycrystalline material coating which has improved the conventional problems.

In order to achieve the above-described object, one aspect of the present invention is a thrust slide bearing that receives an axial load, and includes a rotation side sliding contact member having a sliding contact surface, and a fixed side sliding contact having a sliding contact surface. A member, a rotation-side deformation member that contacts the end surface of the rotation-side sliding contact member opposite to the sliding contact surface, and a fixed contact of the fixed-side sliding contact member that contacts the end surface opposite to the sliding contact surface. The rotation side deformation member and the fixed side deformation member are made of a material that is plastically deformed by sliding contact between the sliding contact surfaces .

In a preferred aspect of the present invention, a groove for supplying a liquid used for lubrication to the sliding contact surface is provided on at least one of the sliding contact surface of the rotation side sliding contact member and the sliding contact surface of the fixed side sliding contact member. The sliding contact surface on which the groove is formed is covered with a crystalline material .

A preferred embodiment of the present invention, prior Symbol groove, Ri radial grooves der of U-shaped cross section extending in the radial direction,
The sliding contact surface which radial grooves are formed, characterized in that the front surface shape changing portion is configured curved or external angle is equal to or less than 30 degrees.
In a preferred aspect of the present invention, the thicknesses of the rotating side deformable member and the fixed side deformable member are within a range of 0.1 mm to 0.5 mm.

In a preferred aspect of the present invention, the crystalline material is polycrystalline diamond .
In a preferred aspect of the present invention, the sliding contact surface of the rotation side sliding contact member and the sliding contact surface of the fixed side sliding contact member are made of SiC (silicon carbide).

In a preferred aspect of the present invention, the rotating side deformable member and the fixed side deformable member are made of fluororesin or polyethylene .

In another aspect of the present invention, a casing, an impeller housed in the casing, a shaft that rotates integrally with the impeller, a motor that rotates the shaft, and the shaft are rotatably supported. and a plurality of bearings, pumped fluid is a ultra-pure water der Ru pump, at least one of said plurality of bearing is characterized in that a said thrust sliding bearing.

  According to the present invention, even if the sliding contact surface of the sliding contact member is tilted when the thrust bearing is assembled, the sliding member is rotated while pressing each other, whereby the deformable member is deformed and the tilt of the sliding contact surface is improved. Is done. In addition, according to the present invention, since the entire sliding contact surface is formed of a smooth surface, a coating of a crystalline material (for example, diamond) is coated on the sliding contact surface without forming pinholes or exposed portions. be able to.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 4 is a cross-sectional view of an all-around flow type canned motor pump provided with a thrust bearing device according to an embodiment of the present invention. As shown in FIG. 4, the pump is fixed to a pump casing 10, a canned motor 11 accommodated in the pump casing 10, a shaft 12 rotated by the canned motor 11, and an end portion of the shaft 12. And an impeller 15. The pump casing 10 has a casing outer cylinder 10A, and a suction casing 10B and a discharge casing 10C connected to both ends of the casing outer cylinder 10A. The suction casing 10B and the discharge casing 10C have a suction port 10a and a discharge port 10b, respectively.

  The canned motor 11 includes a rotor 11A fixed to the outer peripheral surface of the shaft 12, a stator 11B disposed so as to surround the rotor 11A, a motor outer body 11C to which the stator 11B is fixed, a motor A motor side plate 11D that closes both open ends of the outer cylinder 11C, and a cylindrical can 11E disposed between the rotor 11A and the stator 11B are provided. The stator 11B is sealed in a space formed by the motor outer body 11C, the can 11E, and the motor side plate 11D. A cylindrical liquid flow path 17 is formed between the motor outer cylinder 11C and the casing outer cylinder 10A. The flow path 17 communicates with the suction port 10a and the discharge port 10b. In such a configuration, when the impeller 15 is rotated, the liquid is sucked into the pump casing 10 from the suction port 10 a and is pressurized by the rotating impeller 15. The pressurized liquid is discharged from the discharge port 10 b through the flow path 17.

  The shaft 12 is rotatably supported by radial bearings 20 and 21 disposed at both ends thereof, and is supported by a thrust bearing 22 and an auxiliary thrust bearing 23. The thrust bearing 22, the radial bearings 20, 21 and the auxiliary thrust bearing 23 are all sliding bearings. The thrust bearing 22 is for receiving a thrust load generated during operation of the pump. Since the liquid is pressurized by the rotation of the impeller 15 during the operation of the pump, the pressure received by the discharge side surface of the impeller 15 is higher than the pressure received by the suction side surface. A thrust load is generated by imbalance of pressure acting on the impeller 15. The thrust bearing 22 is for receiving a thrust load generated in a direction from the discharge port 10b toward the suction port 10a. On the other hand, the auxiliary thrust bearing 23 is for receiving a thrust load in the opposite direction (direction from the suction port 10a to the discharge port 10b) at the time of starting the pump or the like. The thrust bearing 22, the radial bearings 20, 21 and the auxiliary thrust bearing 23 are infiltrated with the liquid taken into the pump casing 10, and are lubricated by the liquid.

  FIG. 5 is a cross-sectional view showing the thrust bearing 22 and the radial bearing 21 shown in FIG. 6 is a cross-sectional view taken along line BB shown in FIG. The radial bearing 21 has a rotation-side radial sliding contact member 26 fixed to the outer peripheral surface of the shaft 12 and a fixed-side radial sliding contact member 28 fixed to a fixed base (fixed-side bearing bracket) 27. . The thrust bearing 22 includes a rotation-side thrust sliding contact member 30 that rotates integrally with the shaft 12, and a fixed-side thrust sliding contact member 31 that is disposed to face the rotation-side thrust sliding contact member 30. The rotation-side thrust sliding contact member 30 and the fixed-side thrust sliding contact member 31 have annular sliding contact surfaces that face each other. The rotation side thrust sliding contact member 30 and the fixed side thrust sliding contact member 31 are made of a ceramic such as SiC (silicon carbide).

  The rotation side thrust sliding contact member 30 is held by a rotation base (rotation side bearing bracket) 33 fixed to the shaft 12. An annular edge 33a is formed on the rotation base 33, and the rotation-side thrust sliding contact member 30 is disposed inside the edge 33a. A bearing pressing ring 34 formed of an elastic material such as rubber is disposed between the edge 33 a and the rotation side thrust sliding contact member 30, and the bearing pressing ring 34 allows the rotation side thrust sliding contact member 30 to move. The radial position is fixed.

  The fixed-side thrust sliding contact member 31 is held on the fixed base 27. The position of the fixed base 27 is fixed. An annular edge portion 27a is formed on the fixed base 27, and a fixed-side thrust sliding contact member 31 is disposed inside the edge portion 27a. A bearing pressing ring 36 made of an elastic material such as rubber is disposed between the edge portion 27 a and the fixed-side thrust sliding contact member 31. The radial position is fixed.

  A sheet (rotation side deformation member) 40 is disposed adjacent to the rotation side thrust sliding contact member 30. The sheet 40 is in contact with the end surface on the opposite side to the sliding contact surface of the rotation side thrust sliding contact member 30. The sheet 40 is sandwiched between the rotation-side thrust sliding contact member 30 and the rotation base 33, and the thrust load between the rotation-side thrust sliding contact member 30 and the rotation base 33 is transmitted via the sheet 40. The Similarly, a sheet (fixed side deformation member) 41 is disposed adjacent to the fixed side thrust sliding contact member 31. The sheet 41 is in contact with the end surface of the fixed-side thrust sliding contact member 31 opposite to the sliding contact surface. The sheet 41 is sandwiched between the fixed-side thrust sliding contact member 31 and the fixed base 27, and the thrust load between the fixed-side thrust sliding contact member 31 and the fixed base 27 is transmitted via the sheet 41. The Thus, the rotation side thrust sliding contact member 30 and the fixed side thrust sliding contact member 31 are sandwiched between the two sheets 40 and 41.

  These sheets 40 and 41 have the same shape and are formed of the same material. Therefore, hereinafter, the sheet 40 in contact with the rotation side thrust sliding contact member 30 will be described. FIG. 7 is a perspective view showing the seat 40. As shown in FIG. 7, the sheet 40 has an annular shape. The sheet 40 has a shape that is larger than the area of the sliding contact surface and covers the entire end surface (surface opposite to the sliding contact surface) of the sliding contact member. The thickness of the sheet 40 is preferably in the range of 0.1 mm to 0.5 mm. The material of the sheet 40 is preferably a material that can be deformed with a low load, and a resin material is suitable. For example, a fluororesin (such as polytetrafluoroethylene) is preferably used.

  Since the sliding contact members 30 and 31 are respectively installed on the deformable sheets 40 and 41, even if the sliding contact surfaces of the sliding contact members 30 and 31 are inclined during the assembly of the thrust bearing 22, the sliding contact members are provided. By rotating 30 and 31 while pressing each other, the sheets 40 and 41 are deformed, and the inclination of the sliding contact surface is improved. As a result, the sliding contact surfaces of the sliding contact members 30 and 31 are in surface contact with each other. FIG. 8A is a schematic diagram showing a state in which the sliding contact surfaces 30 and 31 are in contact with each other while the sliding contact members 30 and 31 are inclined, and FIG. It is a schematic diagram which shows the state which has received. As can be seen from FIG. 8B, the sliding surfaces of the sliding members 30 and 31 are corrected to a plane perpendicular to the rotating shaft 12 (indicated by a one-dot chain line) by deformation of the sheets 40 and 41. Thereby, the partial wear of the sliding contact members 30 and 31 can be suppressed, and the life of the thrust bearing 22 can be extended.

  As the material of the sheets 40 and 41, an elastomer such as rubber can be used. However, in the case of elastic deformation, a load is applied to the slidable contact members 30 and 31 according to the amount of deformation, so that the contact pressure in the slidable contact surface becomes nonuniform. Therefore, it is preferable that the deformation of the sheets 40 and 41 is mainly plastic deformation, and the sheets 40 and 41 are made of a material that is plastically deformed by the sliding contact of the sliding members 30 and 31 due to the thrust load generated during the pump operation. Is preferably formed. Specifically, a material having a small compressive strength and compressive yield stress is preferable, and a material having a compressive strength of 50 MPa or less and a compressive yield stress of 30 MPa or less is particularly preferable. Furthermore, a material having high stability with respect to the handling liquid and low water absorption is preferable. Examples of such a material include polyethylene in addition to the fluororesin.

  FIG. 9A is a plan view of the fixed-side thrust sliding contact member 31, and FIG. 9B is a longitudinal sectional view of the fixed-side thrust sliding contact member 31. A plurality of radial grooves 45 extending in the radial direction are formed on the sliding contact surface 31 a of the fixed-side thrust sliding contact member 31. The radial groove 45 has a U-shaped cross-sectional shape, and the radial groove 45 and the sliding contact surface 31a are connected by a smooth curved surface. The entire sliding contact surface 31a including the radial groove 45 is covered with polycrystalline diamond. The diamond coating method is not particularly limited, but the method described in Patent Document 1 (Japanese Patent Laid-Open No. 2006-275286) can be applied.

  When the diamond film is formed on the sliding contact surface including the spiral groove as shown in FIG. 2A, problems such as corrosion by ultrapure water and peeling due to cracking of the diamond film occur as described above. The cause is thought to be the following mechanism. The groove formed by laser processing on the sliding contact member made of SiC has a width of about 1 mm and a depth of about 10 μm. FIG. 10 shows a state in which this slidable contact member is coated with polycrystalline diamond. As shown in FIG. 10, a sharp edge portion is formed on the surface of the sliding contact member by laser processing. The diamond crystal cannot follow the change in the surface shape of the diamond crystal, so that a pinhole is formed or the edge portion is left uncovered. When the handling liquid is ultrapure water, the ultrapure water enters from the pinhole and the surface of the sliding contact member is corroded or the exposed edge portion is corroded.

  Further, if there is a part having a large change in surface shape such as an edge part, even if the parts are coated with diamond, when the sliding members come into sliding contact with each other, stress concentrates on the part. Since the diamond film is brittle, it cannot withstand such stress concentration and cracks and peels off from the sliding contact member.

  On the other hand, as shown in FIG. 11, if the sliding contact surface does not have a sharp shape change and has a gentle shape, the diamond crystal can follow the surface shape change and form a pinhole or the like. There is no. Further, since the stress concentration is relaxed, the stress concentration enough to peel off the diamond film does not occur.

  In the present embodiment, based on such reasons, a radial groove 45 having a U-shaped cross section that is wider than the spiral groove shown in FIG. 2A is formed on the sliding contact surface 31a. FIG. 12 is a cross-sectional view along a plane perpendicular to the extending direction of the radial groove 45. The radial groove 45 has a size that can be transferred to the sliding contact member 31 as a shape of a mold for forming the sliding contact member 31 and can be formed by grinding. As shown in FIG. 12, the entire radial groove 45 has a shape that draws a gentle arc, and the connecting portion between the radial groove 45 and the sliding contact surface 31a is also formed as a smooth curved surface R1.

  FIG. 13 is a cross-sectional view taken along line CC shown in FIG. As shown in FIG. 13, the inner peripheral edge and the outer peripheral edge of the sliding contact surface 31a are formed with a smooth curved surface R2. Similarly, the inner peripheral edge and the outer peripheral edge of the sliding contact surface of the rotation-side thrust sliding contact member 30 are also formed with smooth curved surfaces. In the embodiment shown in FIG. 13, the inner peripheral edge and the outer peripheral edge of the end surface opposite to the sliding contact surface 31a are also formed as the curved surface R2, but only both peripheral portions of the sliding contact surface 31a are formed as curved surfaces. May be.

  In the present embodiment, the groove width W is about 2 mm, and the groove depth D is about 0.2 mm. Considering the accuracy and ease of forming the rotation side sliding contact member with a mold, it is preferable that the width W is in the range of 2 to 3.5 mm and the depth D is in the range of 0.2 to 0.25 mm.

  As described above, since all of the slidable contact surfaces to be diamond-coated are composed of smooth surfaces including a flat surface, there is no portion having a large surface shape change. Therefore, it is possible to suppress the formation of pinholes and exposed portions in the diamond coating, and to reduce stress concentration. As a result, corrosion of the sliding contact member by ultrapure water and peeling of the diamond coating are suppressed, and the life of the thrust sliding bearing is extended.

  In the present embodiment, all the surface shape change portions in the sliding contact surface are configured by curved surfaces. However, if the surface shape change locations are large obtuse angles, they may not be configured by a curved surface. For example, as shown in FIG. 14, if the outer angle of the surface shape change portion (corner portion) is 30 degrees or less, pinhole formation can be suppressed and stress concentration can be reduced. However, it is most preferable to form the surface shape change portion with a curved surface, and particularly to form the surface shape change portion so that the cross section has an arc shape. In this embodiment, the radial groove is formed on the fixed-side thrust sliding contact member. However, the radial groove may be formed on the rotation-side thrust sliding contact member, or the radial groove may be formed on both sliding contact members. Also good. However, it is more preferable that the radial groove is provided only in one of the fixed side thrust sliding contact member and the rotation side thrust sliding contact member. In addition, the radial groove may not be parallel to the radial direction but may have a shape inclined with respect to the radial direction, and the entire cross section of the radial groove changes gently, and the radial groove and the slidable contact surface The connection part should just be formed in the shape which changes gently.

  The material for covering such a sliding member having an improved surface shape is not limited to polycrystalline diamond, but may be a crystalline material, particularly a polycrystalline material that is a hard and brittle material film. It is possible to exert the same effect. Polycrystalline diamond is particularly effective because of its remarkable properties (polycrystalline, hard and brittle).

  In the present embodiment, the life of the thrust sliding bearing can be greatly extended by the synergistic effect of the improvement of the bearing per piece and the improvement of the surface shape in the sliding contact surface of the bearing. Further, since the surface shape of the slidable contact surfaces is smooth, the contact pressure between the slidable contact surfaces is hardly changed, and uneven wear can be further suppressed.

  The above two improvements (deformation member and coating) are sufficiently effective even when each of them is used alone. For example, the deformable members (sheets 40 and 41) can be applied to a thrust sliding bearing without a coating, and the same effect can be obtained. Further, the deformable member can also be applied to a thrust slide bearing that is coated with a material other than diamond. The deformable member is particularly effective in the case of a thin and easily damaged film such as a diamond coating. The sliding surface of the auxiliary thrust bearing 23 may be coated with a diamond coating in the same manner, or a deformable member may be applied.

  The thrust sliding bearing of the present embodiment can be applied not only to the pump shown in FIG. 4 but also to other rotating machines that generate a thrust load.

  The embodiment described above is described for the purpose of enabling the person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention should not be limited to the described embodiments, but should be the widest scope according to the technical idea defined by the claims.

It is sectional drawing which shows a thrust sliding bearing typically. FIG. 2A is a plan view showing the fixed sliding member, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. It is a figure which shows the state which the sliding contact surface inclines. 1 is a cross-sectional view of an all-around-flow canned motor pump including a thrust bearing device according to an embodiment of the present invention. It is sectional drawing which shows the thrust bearing and radial bearing which are shown in FIG. FIG. 6 is a sectional view taken along line B-B shown in FIG. 5. It is a perspective view which shows a sheet | seat. FIG. 8A is a schematic view showing a state in which the sliding contact surfaces are in contact with each other while the sliding contact member is tilted, and FIG. 8B shows a state in which the sliding contact member receives a thrust load. It is a schematic diagram. 9A is a plan view of the fixed-side thrust sliding contact member, and FIG. 9B is a longitudinal sectional view of the fixed-side thrust sliding contact member. It is a figure which shows the state by which the polycrystalline diamond coating was made | formed by the conventional sliding contact member. It is a figure which shows the state by which the polycrystalline diamond coating was made | formed on the smooth sliding contact surface. It is sectional drawing along the surface perpendicular | vertical with respect to the direction where a radial groove is extended. It is CC sectional view taken on the line shown to Fig.9 (a). It is sectional drawing which shows the surface shape change location (corner part) whose outside angle is 30 degrees or less.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pump casing 11 Canned motor 12 Shaft 15 Impeller 20, 21 Radial bearing 22 Thrust bearing 23 Auxiliary thrust bearing 26 Rotation side radial sliding contact member 27 Fixed base 28 Fixed side radial sliding contact member 30 Rotation side thrust sliding contact member 31 Fixed Side thrust sliding contact member 33 Rotating base 34, 36 Shaft pressing ring 40, 41 Sheet (deformable member)
45 Radial groove

Claims (8)

A thrust slide bearing that receives an axial load,
A rotation side sliding contact member having a sliding contact surface;
A fixed sliding contact member having a sliding contact surface;
A rotation-side deformation member in contact with an end surface of the rotation-side sliding contact member opposite to the sliding contact surface;
A fixed-side deformation member in contact with an end surface of the fixed-side sliding contact member opposite to the sliding contact surface ;
The thrust sliding bearing, wherein the rotation side deformation member and the fixed side deformation member are made of a material that is plastically deformed by sliding contact between the sliding contact surfaces . A groove for supplying a liquid used for lubrication to the sliding contact surface is formed on at least one of the sliding contact surface of the rotating side sliding contact member and the sliding contact surface of the fixed side sliding contact member,
  The thrust sliding bearing according to claim 1, wherein the sliding contact surface in which the groove is formed is covered with a crystalline material. Before SL groove, Ri radial grooves der of U-shaped cross section extending in the radial direction,
The sliding contact surface which radial grooves are formed, the thrust sliding bearing according to claim 2, characterized in that the table surface shape changing portion is configured curved or external angle is equal to or less than 30 degrees. 4. The thrust bearing according to claim 1, wherein thicknesses of the rotation-side deformation member and the fixed-side deformation member are in a range of 0.1 mm to 0.5 mm. 5. 4. The thrust slide bearing according to claim 2, wherein the crystalline material is polycrystalline diamond. The thrust sliding bearing according to any one of claims 1 to 5, wherein the sliding contact surface of the rotation side sliding contact member and the sliding contact surface of the fixed side sliding contact member are made of silicon carbide. The thrust sliding bearing according to any one of claims 1 to 6, wherein the rotating side deforming member and the fixed side deforming member are made of fluororesin or polyethylene. A casing,
An impeller housed in the casing;
A shaft that rotates integrally with the impeller;
A motor for rotating the shaft;
And a plurality of bearings for rotatably supporting the shaft, the pumped fluid is a ultra-pure water der Ru pump,
The pump according to claim 1, wherein at least one of the plurality of bearings is a thrust sliding bearing according to claim 1.

Images