JP6639556B2 - Sliding member and manufacturing method thereof - Google Patents

Description

  The present invention relates to a sliding member and a method for manufacturing the same.

  As one type of drainage pump, a preceding standby operation pump is known. In order to cope with a sudden increase in the amount of water such as a guerrilla downpour, the preparatory standby operation pump can be operated at full speed in advance in an anhydrous state (preliminary standby operation) or can perform drainage in a mixed gas-water state. Has become. A sliding member applicable to such a preceding standby operation pump is disclosed in, for example, Patent Document 1.

  Patent Document 1 discloses a pump shaft / bearing structure including a sliding member base and sliding particles. It is described that the sliding contact particles are scattered and fixed on the surface of the sliding member base, protrude from the surface of the sliding member base, and slide on the sliding member.

  A sliding member having sliding contact particles as a sliding surface as described in Patent Document 1 is excellent in response to thermal expansion of the sliding member and in heat dissipation due to a space formed between the sliding contact particles. It has features. Further, when the sliding member is used, for example, in a shaft / bearing structure of a pump, when the sliding member rotates, a liquid such as water is appropriately applied between the sliding particles and the sliding member from the interparticle region. Supplied, functions as a lubricant, and also has the effect of improving lubricity.

JP-A-2006-217727 (published on December 15, 2016)

  However, in the above-described conventional techniques, the performance of the obtained sliding member tends to vary depending on the manufacturing conditions. For example, the peeling resistance of the sliding contact particles constituting the sliding contact surface is an important performance in the sliding member, but manufacturing conditions for reliably manufacturing a sliding member including the sliding contact particles having excellent peeling resistance. Had room for further improvement.

  In addition, the sliding member as described above has a specific problem because the sliding surface is composed of a plurality of sliding particles. That is, if the fixed state of each sliding contact particle or the contact area with the sliding member varies, the fixing strength of the sliding contact particle and the pressure applied to the sliding contact particle vary depending on the sliding contact particle. There is a problem that this is one of the factors that lead to particle separation and uneven wear.

  In view of the above, there is a need for manufacturing conditions that provide sliding members capable of suppressing uneven wear while providing sliding contact particles having excellent peel resistance, and that the sliding members are stably provided. Was required.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a sliding member that includes sliding contact particles having excellent peel resistance and that can suppress uneven wear.

The inventors of the present application have conducted intensive studies in order to achieve the above object, and as a result, the particle size range of the raw material particles and the ratio of the area of the particle sliding contact surface of the sliding particles to the projected area are within a predetermined range. As a result, the present inventors have found that a sliding member capable of suppressing uneven wear can be easily provided while providing sliding contact particles having excellent peeling resistance, and the present invention has been completed. That is, the present invention includes the following inventions.
[1] A sliding member that slides relatively to a sliding member,
A sliding member base,
Sliding contact particles scattered and fixed on the surface of the sliding member base,
The sliding contact particles protrude from the surface of the sliding member base, and have a particle sliding contact surface that slides on the sliding member,
The raw material particles of the sliding contact particles have a particle size range within ± 20% of the average particle size of the raw material particles,
The sliding member, wherein a ratio of an area of the particle sliding contact surface to an area of a projected portion of the sliding particle is 0.6 or more and 0.95 or less.
[2] The sliding member according to [1], wherein the average particle diameter of the raw material particles is 10 μm or more and 250 μm or less.
[3] The sliding member according to [1] or [2], wherein the sliding particles have an embedding rate of 50% or more.
[4] The sliding particles are made of diamond, diamond-like carbon, cubic boron nitride, glassy carbon, alumina, zirconia, silicon carbide, boron carbide, tungsten carbide, silicon nitride, silicide, phosphide, and sulfide. The sliding member according to any one of [1] to [3], including at least one selected from the group consisting of:
[5] fixing the raw material particles of the sliding contact particles on the outer surface of the sliding member base;
Processing the raw material particles by a height of 20% or more and 30% or less with respect to the average particle diameter of the raw material particles to form a particle sliding contact surface,
The method for producing a sliding member, wherein the raw material particles have a particle size range of ± 20% of the average particle size of the raw material particles.
[6] The method for manufacturing a sliding member according to [5], wherein the average particle diameter of the raw material particles is 10 μm or more and 250 μm or less.
[7] The above-mentioned sliding contact particles are composed of diamond, diamond-like carbon, cubic boron nitride, glassy carbon, alumina, zirconia, silicon carbide, boron carbide, tungsten carbide, silicon nitride, silicide, phosphide, and sulfide. The method for producing a sliding member according to [5] or [6], comprising at least one member selected from the group consisting of:

  According to the sliding member of one embodiment of the present invention, it is possible to provide a sliding member including sliding contact particles having excellent peel resistance and capable of suppressing uneven wear.

  According to the manufacturing method of one embodiment of the present invention, the conditions for fixing the sliding particles can be made uniform, and the pressure (surface pressure) applied to the sliding particles can be made uniform. Therefore, it is possible to provide a sliding member including sliding contact particles having excellent peeling resistance and capable of reducing an excessive load applied to some of the sliding contact particles. Therefore, a sliding member capable of suppressing uneven wear can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is the cross-sectional schematic which shows the cross section perpendicular | vertical to an axial direction of the shaft / bearing structure in one Embodiment of this invention, and the shaft member as a sliding member. FIG. 2A is a schematic cross-sectional view of a sliding member manufactured using raw material particles having a wide particle size range. FIG. 2B is a schematic cross-sectional view of a sliding member manufactured using raw material particles having a narrow particle size range. FIG. 2 shows the raw material particles as approximate spherical particles for ease of explanation. FIG. 2 is a top view illustrating a configuration of the sliding member according to the embodiment of the present invention as viewed from an outer surface side. It is a longitudinal section of a pump concerning one embodiment of the present invention. It is a longitudinal section of a slide bearing device of a pump concerning one embodiment of the present invention.

  An embodiment of the present invention will be described below, but the present invention is not limited to this. The present invention is not limited to each configuration described below, and various modifications can be made within the scope shown in the claims, and technical means disclosed in different embodiments and examples, respectively. Embodiments and examples obtained by appropriately combining are also included in the technical scope of the present invention. In addition, all of the academic documents and patent documents described in this specification are incorporated herein by reference. Unless otherwise specified in this specification, “A to B” representing a numerical range means “A or more and B or less”.

[1. Sliding member)
A description will be given of a shaft member having a shaft / bearing structure in a rotating mechanism used in a pump capable of discharging a slurry liquid, as a sliding member that slides relatively to a member to be slid. In the present embodiment, a shaft member as a sliding member will be described, but the sliding member of the present invention is not necessarily limited to this. For example, the present invention can be applied to a bearing member in a shaft / bearing structure that slides relatively to a shaft member. Further, for example, the present invention can also be applied to a sliding member such as a thrust bearing that slides in a plane relative to a member to be slid.

  The configuration of the shaft member 10 as the sliding member of the present embodiment in the shaft / bearing structure 1A will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view showing a cross section perpendicular to the axial direction of a shaft / bearing structure 1A according to an embodiment of the present invention.

  As shown in FIG. 1, the shaft / bearing structure 1A includes a shaft member 10 as a sliding member and a bearing member 11 as a slidable member. The shaft member 10 is a cylindrical shaft sleeve. The shaft member 10 is not limited to the shaft sleeve, but may be a shaft. On the other hand, the bearing member 11 has a cylindrical shape in which the shaft member 10 is housed, and supports the shaft member 10.

  The bearing member 11 is made of, for example, a hard ceramic or a cemented carbide and has a hardness equal to or higher than that of silica sand, and thus has excellent wear resistance to silica sand and the like contained in the slurry liquid. Further, the covalent or ionic bonding ceramics, which are hard ceramics, have a low affinity for metal components such as metal scraps rarely contained in the slurry liquid, and therefore are contained in the slurry liquid to the bearing member 11. It is easy to prevent adhesion of metal components such as scrap metal. The surface of the bearing member 11 may be processed to form a film for lowering the friction coefficient or improving the wear resistance.

  As shown in FIG. 1, the shaft member 10 includes at least a sliding member base 10a and sliding contact particles 10b scattered and fixed on the surface of the sliding member base 10a. The sliding contact particles 10b protrude from the surface of the sliding member base 10a. In FIG. 1, only a part of the sliding contact particles 10b is shown. The sliding contact particles 10 b are formed by fixing and processing raw material particles of sliding contact particles (hereinafter, also referred to as “raw material particles”) at the base of the sliding member, and have a particle sliding contact surface 12. That is, “raw material particles” mean sliding particles before being fixed to the base of the sliding member. The particle sliding contact surface 12 forms a member sliding contact surface 13 which is a circumferential surface around the axis of the shaft member 10.

  The sliding contact particles 10b include diamond, diamond-like carbon (hereinafter referred to as “DLC”), cubic boron nitride, glassy carbon, alumina, zirconia, silicon carbide, boron carbide, tungsten carbide, silicon nitride, It is preferable to include at least one selected from the group consisting of silicides, phosphides, and sulfides. These may be single crystal particles, polycrystalline particles, or sintered bodies. That is, the diamond includes single crystal particles of diamond, synthetic polycrystalline particles of diamond, and particles obtained by grinding a diamond sintered body. In addition, the DLC includes a granulated DLC powder using a binder and particles obtained by pulverizing a sintered body of the DLC powder. Also included are particles produced by cutting and firing or cutting after firing the ceramic green sheet, and molded particles obtained by solidifying ceramic powder such as alumina. The tungsten carbide includes WC, W2C, and a composite material of WC and W2C.

  The average particle diameter of the raw particles of the sliding contact particles 10b is preferably 10 μm or more and 250 μm or less. It is more preferably from 20 μm to 200 μm, further preferably from 30 μm to 160 μm, and particularly preferably from 50 μm to less than 125 μm. The average particle size is a D50 value measured by a laser diffraction type particle size distribution analyzer: SALD-2100, Shimadzu Corporation.

  In the present specification, the `` particle size range '' of the raw material particles is a range of the particle diameters represented by the minimum diameter particles and the maximum diameter particles in all the raw material particles scattered and fixed on the surface of the sliding member base. is there. The minimum particle size and the maximum particle size of the raw material particles are measured by a laser diffraction type particle size distribution measuring device: SALD-2100, Shimadzu Corporation. The particle size range of the raw material particles of the sliding contact particles 10b is within ± 20% of the average particle size of the raw material particles. For example, "the particle size range of the raw material particles is within ± 20% of the average particle size of the raw material particles" means that the particle size of the raw material particles is at least 0.8 times the average particle size of the raw material particles, It means that the average particle diameter of the raw material particles is 1.2 times or less. The reason why the particle size range of the raw material particles is preferably within the above range will be described with reference to FIG.

  FIG. 2A is a schematic cross-sectional view of a sliding member manufactured using raw material particles having a wide particle size range. FIG. 2B is a schematic cross-sectional view of a sliding member manufactured by a conventional method using raw material particles having a narrow particle size range. In FIG. 2, the raw material particles are described as being approximately spherical particles.

In FIG. 2A, for example, consider a case where the raw material particles have an average particle size of 100 μm and a particle size range of ± 50% of the average particle size. Raw material particles having a maximum particle diameter (hereinafter, also referred to as "maximum diameter particles") 10b ₁ is 150μm particle size, the raw material particles having an average particle size (hereinafter, "average diameter particle") 10b _2, the particles diameter of 100 [mu] m, the raw material particles having a minimum particle size (hereinafter, also referred to as "minimum diameter particles") 10b ₃ is a particle size is 50 [mu] m. The average plating as to fill 60% of the height of the particle size is subjected (i.e., plating thickness and a 60 [mu] m), the maximum size particles 10b ₁ is 40% of the height of the particle size is only embedded by plating Not so, the peel resistance is poor. On the other hand, the minimum diameter particles 10b ₃ is completely filled in the plating, it can not form particles sliding surface. As described above, when the raw material particles having a large particle size range are used, it is difficult to make the sliding contact area of each sliding contact particle within a predetermined range.

On the other hand, in FIG. 2B, for example, consider a case where the raw material particles have an average particle diameter of 100 μm and a particle size range of ± 20% of the average particle diameter. Maximum diameter particles 10b ₄ is 120μm particle size, the average diameter particle 10b ₅ is 100μm particle size, minimum diameter particles 10b _6, the particle size is 80 [mu] m. If plating as 60% of the height of the average particle diameter is filled to (i.e., plating thickness and a 60 [mu] m), the maximum diameter particles 10b ₄ 50% of the height of the particle size is fixed by plating minimum diameter particles 10b ₆ also 75% of the height of the particle size is fixed by plating. As described above, when the raw material particles having a narrow particle size range are used, the sliding contact area of each sliding contact particle can be easily adjusted to a predetermined range. Embedded ratio) can be easily ensured. Further, since the surface pressure applied to the sliding contact particles can be made uniform, the particle sliding contact surface can be formed by the sliding contact particles having excellent peel resistance.

  The size of the sliding contact area for each sliding contact particle is made uniform, and the ratio of the area of the particle sliding contact surface (hereinafter also referred to as the sliding contact area) to the area of the projected portion of the sliding contact particle (hereinafter also referred to as the projected area) ( If (sliding contact area / projected area) is 0.6 or more and 0.95 or less, the surface pressure on the sliding member when the sliding member slides on the sliding member is within a predetermined range. Can be. Thereby, it is possible to suppress uneven wear of the sliding contact particles when the sliding member and the sliding member are in sliding contact with each other, and it is possible to suppress the wear of the sliding member. In addition, when the sliding member is significantly worn, the sliding member is unevenly worn. With the above configuration, the uneven wearing can be suppressed.

  The ratio between the sliding contact area and the projected area is intended to mean the average value of the ratio between the sliding contact area and the projected area on the unit surface of the sliding member base 10a. Specifically, on the unit surface of two or more sliding member bases 10a, the ratio of the sum of the sliding contact areas to the sum of the projected areas is calculated, and the average value is calculated based on the ratio. Hereinafter, the sliding contact area and the projected area will be described with reference to FIG.

  The “area of the particle sliding contact surface (sliding contact area)” is intended to mean the sum of the areas of the unit surfaces of the sliding member base 10a surrounded by the outer periphery of the particle sliding contact surface 12. The “area of the projected portion of the sliding contact particle (projected area)” means the sum of the areas of the projected portion 31 on the unit surface of the sliding member base 10a. The projection portion is a portion surrounded by the outer periphery of the sliding contact particle when viewed from the vertical direction on the surface of the sliding member base. For example, when the sliding contact particle is a rectangular parallelepiped, the sliding contact area and the projected area are the same (that is, the sliding contact area / projected area = 1). The sliding contact area and the projected area are measured based on a photomicrograph obtained by observing the unit surface of the sliding member base 10a with a laser microscope. Note that the measurement may be performed by excluding the sliding particles protruding from the unit area in the microscope observation range. Further, the outer periphery of the particle sliding contact surface 12 and the outer periphery of the projection portion 31 may be partially overlapped.

  The unit surface of the sliding member base 10a selected when obtaining the average value of the ratio between the sliding contact area and the projected area on the unit surface of the sliding member base 10a is at least two or more, and is 10 or more. Is preferably 20 or more, more preferably 40 or more, and particularly preferably 80 or more. Also, the unit surface of the sliding member base 10a selected when obtaining the average value of the sum of the areas of the particle sliding contact surfaces 12 is selected at random and without bias from the entire sliding member base 10a. Is preferred. The size of the unit surface is not particularly limited, and is appropriately set according to the size of the sliding member base 10a.

  For example, when the sliding member base 10a is a shaft sleeve of φ85 mm × 100 mmL, the unit surface of the sliding member base 10a selected when obtaining the average value of the sum of the areas of the particle sliding contact surfaces 12 is a circle. A total of 80 locations (10 × 8), 10 locations from the direction and 8 locations from the axial direction, can be selected. At this time, the unit surface of the sliding member base 10a may be 1 mm × 1 mm.

  The sliding member base 10a may be configured of a base. The base may be formed of a generally used material such as SUS304 or a resin. Further, the surface shape of the sliding member base 10a may be flat, may have an uneven structure, or may have a curved surface.

  Further, the sliding member base 10a may include a base and a metal film or a brazing material formed on the surface of the base. As will be described later, the fixing of the raw material particles of the sliding contact particles 10b on the outer surface of the sliding member base 10a uses electrodeposition, brazing, and Spark Plasma Sintering (hereinafter, referred to as SPS). The metal film or the brazing material functions as a fixing member for forming the sliding contact particles. Further, the metal film and the brazing material can prevent a situation in which the base material is worn due to contact with other particles.

  The average height (hereinafter, referred to as “projection height”) from the surface of the sliding member base 10a to the tip of the sliding contact particle 10b is preferably 0.8 μm or more, and more preferably 1.0 μm or more. More preferred. Note that the leading end of the sliding contact particle 10b at the protruding height is intended to be the leading end of the sliding contact particle 10b after the above-described processing, that is, the particle sliding contact surface 12.

  Further, the protrusion height is preferably 40% or less, more preferably 30% or less, of the average particle diameter of the raw material particles of the sliding contact particles 10b. That is, for example, when the average particle diameter of the raw material particles is 150 μm, the protrusion height is preferably 60 μm or less, and more preferably 45 μm or less. If the protruding height is the above configuration, the fixing strength of the sliding contact particles 10b tends to increase.

  The embedding rate of the sliding particles 10b is preferably at least 50% of the particle diameter of the raw material particles of the sliding particles 10b. If the embedding ratio is the above-described configuration, the fixing strength of the sliding contact particles 10b tends to increase. The embedding ratio is intended to mean the ratio of the height of the portion embedded in the sliding member base 10a to the particle diameter of the raw material particles of the sliding contact particles 10b in the height of the sliding contact particles 10b. I do. The particle diameter of the raw material particles of the sliding contact particles means the major diameter of each sliding contact particle before being fixed to the base of the sliding member. The particle size is measured by a laser diffraction type particle size distribution measuring device: SALD-2100, Shimadzu Corporation. The height of the portion embedded in the sliding member base 10a is, for example, the deepest portion of the portion of the sliding contact particle 10b embedded in the sliding member base 10a in FIG. When a perpendicular is dropped from the surface, it can be obtained by measuring the length of the perpendicular. Note that the “surface of the sliding member base 10a” in FIG. 1 refers to a surface of the sliding member base 10a that is parallel to and opposed to the inter-member sliding contact surface 13. .

  When the sliding particles are fixed to the outer peripheral surface of the shaft member, the particle sliding contact surface 12, that is, the end on the bearing member 11 side is centered on the axis of the shaft member 10 when viewed from the axial direction of the shaft member 10. And on the same circumference. That is, as shown in FIG. 1, the inter-member sliding contact surface 13 which is a circumferential surface around the axis of the shaft member 10 is formed by the particle sliding contact surface 12. The inter-member sliding contact surface 13 is a surface that comes into sliding contact with the bearing member 11 that is a slidable member when the shaft member 10 rotates.

  When the sliding particles 10b are fixed in the thrust bearing, the tips of the sliding particles 10b, that is, the ends on the bearing member 11 side are in the same plane when viewed from the vertical direction of the surface of the sliding member base 10a. It is in.

  According to the above configuration, when the shaft member 10 rotates, only the sliding contact particles 10b are in sliding contact with the bearing member 11. Therefore, the shaft member 10 has a low coefficient of friction and suppresses the generation of heat due to friction, so that the durability is further improved.

<Sliding particles with coating>
In one embodiment of the present invention, the sliding particles may be at least partially covered with a coating. According to the above configuration, the sliding surface of the sliding particles and / or the corners around the sliding surface of the particles can be covered with the coating so that the surface becomes a smooth surface. The surface can be made smooth.

  The coating may cover at least a corner portion of a peripheral portion of the sliding contact surface of the sliding contact particles, and may be formed of a diamond-like carbon film or a glassy carbon film. According to the above configuration, the sliding surface of the shaft member can be made more smooth.

  The coating is formed of a diamond-like carbon film or a glassy carbon film covering the periphery of the sliding contact surface, and the outer surface of the coating at a portion corresponding to a corner from the peripheral portion of the sliding contact surface to the side surface has a curved surface. May be adopted.

  According to the above configuration, the diamond-like carbon film or the glass-like carbon film covers the periphery of the sliding surface of the sliding particles, and the corners from the peripheral portion of the sliding surface to the side surfaces of the sliding particles. The outer surface of the portion corresponding to is curved. Therefore, the smoothness of the sliding contact surface of the sliding member can be further improved, and the aggressiveness of the corner to the slidable member can be reduced.

  The thickness of the coating is preferably 5 μm to 10 μm in order to sufficiently exert the effect of the coating.

  In the case where at least a part of the sliding particles is covered with the coating, and when the tip of the sliding particles, that is, at least a part of the particle sliding surface is covered with the coating, the sliding contact is performed. The protrusion height of the particles is the height from the surface of the fixed layer to the tip of the coating.

<Method of forming coating>
The sliding particles in which at least a part of the sliding particles are coated with a diamond-like carbon film (hereinafter, also referred to as a DLC film) can be adjusted by coating the sliding particles with a DLC film. Known methods for coating the DLC film include a method using a deposition technique using plasma at a vacuum or atmospheric pressure, and a method for electrically depositing a carbon film from a liquid such as an organic solvent. At present, a coating method by a vapor deposition method using a vacuum device is mainly used.

A method of coating a DLC film by a vapor deposition method using a vacuum device is roughly classified into a method using solid carbon as a carbon supply source and a method using a hydrocarbon-based material. As a method of using solid carbon (graphite) as a carbon source, arc ion plating, non-equilibrium magnetron sputtering, and filtered arc ion plating are known. As a method of using a hydrocarbon-based gas (CH ₄ , C ₆ H ₆ , C ₂ H _2, etc.) as a carbon supply source, high-frequency plasma CVD, pulse DC plasma CVD, ionization deposition, plasma ion implantation / film formation. It has been known.

  The sliding contact particles, in which at least a part of the sliding contact particles are coated with the glassy carbon film, are obtained by applying a glass-like carbon resin composition having a thermosetting resin as a main component to the sliding contact particles, and then curing. It can be adjusted by firing and carbonizing in an inert atmosphere or under vacuum.

[2. Manufacturing method of sliding member]
A method for manufacturing a sliding member according to an embodiment of the present invention (hereinafter, also simply referred to as “manufacturing method”) includes a step of fixing raw material particles of sliding contact particles on an outer surface of a base of the sliding member; Processing the raw material particles by a height of 20% or more and 30% or less with respect to the average particle diameter of the particles to form a particle sliding contact surface. Is within ± 20% of the average particle size. According to the above configuration, since the particle diameters of the raw material particles are uniform, it is possible to provide a sliding member including sliding contact particles having excellent peel resistance. Further, since the sliding contact area and the embedding ratio of each sliding contact particle can be made uniform, the surface pressure on the sliding member when the sliding member comes into sliding contact with the sliding member is within a predetermined range. Thereby, it is possible to suppress uneven wear of the sliding contact particles when the sliding member and the sliding member are in sliding contact with each other, and it is possible to suppress the wear of the sliding member.

<Method for fixing raw particles of sliding contact particles>
In one embodiment of the present invention, the fixing of the raw material particles of the sliding contact particles 10b on the outer surface of the sliding member base 10a includes electrodeposition, brazing, and spark plasma sintering (SPS). ) Can be performed. Each fixing method will be described below.

(Fixing method using electrodeposition)
The fixing of the raw material particles of the sliding contact particles 10b on the surface of the sliding member base 10a can be performed by a well-known electrodeposition method. For example, raw material particles of the sliding contact particles 10b are arranged on the surface of the sliding member base 10a. Thereafter, a nickel plating solution is poured so as to obtain a desired filling ratio, and current is supplied in the nickel plating solution. Nickel plating is applied to the surface of the sliding member base 10a, and accordingly, raw material particles of the sliding contact particles 10b are embedded to some extent in the nickel plating film and fixed on the sliding member base 10a.

  Alternatively, for example, the sliding member base 10a whose surface other than the outer surface is masked is arranged in a nickel plating solution containing raw material particles of the sliding contact particles 10b. Thereafter, by energizing in a nickel plating solution by an electrolytic method, a nickel plating film is formed on the outer surface of the sliding member base 10a, and the raw material particles of the sliding contact particles 10b in the nickel plating solution are formed on the nickel plating film. It is embedded to some extent and fixed on the sliding member base 10a. As a plating solution used for electrodeposition, a plating solution made of another metal or alloy may be used.

(Fixing method by brazing)
The fixing of the raw material particles of the sliding contact particles 10b on the surface of the sliding member base 10a can be performed by well-known brazing.

  For example, first, the raw material particles of the sliding contact particles 10b are arranged on the surface of the sliding member base 10a. Next, the raw material particles of the sliding contact particles 10b are spotted and fixed by nickel plating or the like. Thereafter, a paste of a brazing material powder made of Ni-Cr-B-Si or Cu-Ag-In-Ti or the like is applied and heated to a temperature equal to or higher than the melting point of the brazing material. Thereby, the raw material particles of the sliding contact particles 10b are embedded in the brazing material and fixed on the sliding member base 10a.

(Fixing method using SPS)
First, the raw material particles of the sliding contact particles 10b are arranged on the sliding member base 10a, and thereafter, pressure molding is performed by an SPS device at, for example, 950 ° C. and 30 MPa. The raw material particles of the other sliding contact particles 10b that are not held on the sliding member base 10a can be fixed on the sliding member base 10a by removing after removing the pressure.

<Processing method of raw particles of sliding contact particles>
In one embodiment of the present invention, the raw material particles of the sliding contact particles 10b fixed on the sliding member base 10a are processed by a height of 20% or more and 30% or less with respect to the average particle diameter of the raw material particles, A particle sliding contact surface 12 is formed.

  When the sliding contact particles 10b are formed on the outer peripheral surface of the shaft member, the raw material particles are processed so that the particle sliding contact surfaces 12 of the sliding contact particles 10b are on the same circumference. It is formed. That is, the distance from the rotation center axis of the sliding member base 10a to the outermost particle sliding contact surface 12 is made equal so that the particle sliding contact surfaces 12 of the sliding contact particles 10b are on the same circumference. .

  When the sliding particles 10b are formed in the thrust bearing, the raw material particles are processed so that the particle sliding surfaces 12 are coplanar when viewed from the vertical direction of the surface of the sliding member base 10a. , A member sliding contact surface 13 is formed.

  As a method of processing the raw material particles in this manner, a method of grinding with a grindstone such as diamond or silicon carbide, grinding by electric discharge machining, or grinding with an abrasive can be used. An appropriate method may be selected as a method for processing a high-hardness material such as the raw material particles of the sliding contact particles 10b in one embodiment of the present invention.

  The manufacturing method according to one embodiment of the present invention includes a step other than the step of fixing the raw material particles of the sliding particles on the outer surface of the sliding member base and the step of processing the raw material particles to form the particle sliding surface. For example, a step of performing additional plating for adjusting the burying ratio, a step of processing the buried portion, a step of performing a surface treatment, and the like may be included.

[3. pump〕
A pump according to one embodiment of the present invention includes the sliding member according to one embodiment of the present invention. Since the sliding member according to one embodiment of the present invention includes sliding contact particles having excellent peel resistance, the pump according to one embodiment of the present invention can be stably operated for a long time.

  As the pump, for example, a vertical mixed-flow pump device capable of discharging a slurry liquid as shown in FIG. 4 is exemplified. The vertical mixed flow pump device 81 has a suction port 83 at a lower end of a casing 82. A rotatable main shaft 84 is inserted into the casing 82, and an impeller 85 is provided at a lower end of the main shaft 84. At an upper portion of the casing 82, a driving device 86 (electric motor) for driving the main shaft 84 to rotate is provided. The main shaft 84 is rotatably supported by a slide bearing device 87.

  As shown in FIGS. 4 and 5, the main shaft 84 includes a shaft main body 84a and a cylindrical sleeve 84b (an example of a sliding member) that is fitted around the shaft main body 84a at a bearing location. , A bearing 88 slidably in contact with the outer peripheral surface of the sleeve 84b, a housing 89 provided around the bearing 88, and a cylindrical cushioning rubber 90 provided between the bearing 88 and the housing 89. . The housing 89 is a metal cylindrical member, and is fixed to a fixing member 91 provided in the casing 82.

  The bearing 88 includes a cylindrical bearing shell 93 and a bearing body 94 (an example of a slidable member). The inner peripheral surface of the sliding contact particle 94 and the outer peripheral surface of the sleeve 84b are in sliding contact. The sleeve 84b is provided with the fixing layer and the base material according to the embodiment of the present invention.

  According to this, when the main shaft 84 rotates in a predetermined rotation direction, the outer peripheral surface of the sleeve 84b comes into sliding contact with the inner peripheral surface of the bearing body 94. At this time, the slide bearing device 87 is prevented from rotating, and does not rotate together with the main shaft 84.

  The vertical mixed-flow pump device 81 performs a preliminary standby operation, and is switchable between a pumping operation for pumping water and a standby operation for not pumping water. The sliding member according to one embodiment of the present invention does not exhibit a lubricating effect by self-pumping water, and exhibits an effect during standby operation in a dry state in which the sliding resistance of the main shaft 84 with respect to the slide bearing device 87 increases. is there.

  The present invention is not limited to the embodiments described above, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

(Peeling resistance test)
An electrodeposited diamond test piece of 50 mm × 50 mm × 5 mm was cut out from the sliding member manufactured by the method described below. Using the electrodeposited diamond test piece and a high-speed steel pin of φ5 mm × 5 mmL (the sliding tip is φ3 mm), a rotation test was performed for 30 minutes under the conditions of a pressure of 20 kg / mm ² and a peripheral speed of 0.1 m / sec. The surface of the test piece after the friction test was confirmed. "O" indicates that the plurality of sliding contact particles formed by electrodeposition did not fall off the surface of the test piece, and "x" indicates that the plurality of sliding contact particles formed by electrodeposition dropped off the surface of the test piece. It was evaluated. The friction and abrasion tester used was EFM-3-H manufactured by A & D Corporation.

(Example 1)
After the diamond particles (1) described in Table 1 are electrodeposited and fixed on a surface of a SUS304 substrate of 100 mm × 50 mm × 5 mmt with Ni, Ni—P or the like, the tip of the particles is set to a height of 20% of the average particle diameter. Min. After the processing, the embedding rate and the ratio between the sliding contact area and the projected area (hereinafter, also referred to as “A value”) were measured using a laser microscope.

"Evaluation of embedding rate"
A unit surface was set at eight locations in the same manner as in the calculation of the A value described later, the protruding height was measured in a 1 mm × 1 mm square visual field, and the average value of the measured values obtained at eight locations was calculated. Then, the minimum value and the maximum value of the embedding rate were calculated using the maximum particle diameter and the minimum particle diameter and the numerical value of the grinding amount.

"Evaluation of the ratio between sliding contact area and projected area"
Eight unit surfaces (1 mm x 1 mm) were set evenly from the 100 x 50 mm surface of the manufactured sliding member, and each unit surface was observed using a laser microscope (product name: VK-9700, manufactured by Keyence Corporation). , Micrographs were taken. The A value was calculated based on the photograph, and the average of the A values calculated at eight locations was obtained.

(Example 2)
A sliding member was manufactured in the same manner as in Example 1 except that the grinding amount was set to 30% of the average particle diameter.

(Comparative Example 1)
A sliding member was manufactured in the same manner as in Example 1 except that the grinding amount was set to 40% of the average particle diameter.

(Example 3)
A sliding member was manufactured in the same manner as in Example 1 except that the diamond particles (4) shown in Table 1 were used.

(Example 4)
A sliding member was manufactured in the same manner as in Example 3 except that the grinding amount was set to 30% of the average particle diameter.

(Comparative Example 2)
A sliding member was manufactured in the same manner as in Example 1 except that the diamond particles (2) described in Table 1 were used.

(Comparative Example 3)
A sliding member was manufactured in the same manner as in Comparative Example 2 except that the grinding amount was set to 30% of the average particle diameter.

(Comparative Example 4)
A sliding member was manufactured in the same manner as in Example 1 except that the diamond particles (3) shown in Table 1 were used.

(Comparative Example 5)
A sliding member was manufactured in the same manner as in Comparative Example 4, except that the grinding amount was set to 30% of the average particle diameter.

  Table 2 shows the manufacturing conditions of the sliding member, the calculated A value, and the results of the peeling resistance evaluation.

  As described in Table 1, the particles (1) and (2) have a particle size range within ± 20% of the average particle diameter of the raw material particles, but the particles (3) and (4) have The particle size range exceeds ± 20% of the average particle size of the raw material particles. As shown in Table 2, from Examples 1 to 4, the particle size range of the raw material particles is within ± 20% of the average particle size of the raw material particles, and the A value is 0.6 to 0.95. It can be seen that a certain sliding member has sliding contact particles having excellent peel resistance. On the other hand, from Comparative Example 1, even if the particle size range of the raw material particles is within ± 20% of the average particle size of the raw material particles, a sliding member having an A value exceeding 0.95 has poor sliding resistance. It can be seen that the particles have tangent particles. Furthermore, from Comparative Examples 2 to 5, even if the A value is 0.6 or more and 0.95 or less, the sliding member in which the particle diameter range of the raw material particles exceeds ± 20% of the average particle diameter of the raw material particles is not obtained. It can be seen that the particles had sliding contact particles having inferior peel resistance.

  INDUSTRIAL APPLICATION This invention can be utilized suitably for a pump, for example, a preceding standby operation pump.

1A Shaft / bearing structure 10 Shaft member 10a Sliding member base 10b Sliding particles 11 Bearing member 12 Particle sliding surface 13 Sliding surface between members 31 Projection portion

Claims (7)

A sliding member that slides relative to the member to be slid,
A sliding member base,
Sliding contact particles scattered and fixed on the surface of the sliding member base,
The sliding contact particles protrude from the surface of the sliding member base, and have a particle sliding contact surface that slides on the sliding member,
The raw material particles of the sliding contact particles have a particle size range within ± 20% of the average particle size of the raw material particles,
The sliding member, wherein the ratio of the area of the particle sliding contact surface to the area of the projected portion of the sliding particle is 0.6 or more and 0.95 or less.   The sliding member according to claim 1, wherein the average particle diameter of the raw material particles is 10 μm or more and 250 μm or less.   The sliding member according to claim 1, wherein the sliding contact particles have an embedding rate of 50% or more.   The above-mentioned sliding contact particles, from the group consisting of diamond, diamond-like carbon, cubic boron nitride, glassy carbon, alumina, zirconia, silicon carbide, boron carbide, tungsten carbide, silicon nitride, silicide, phosphide, and sulfide The sliding member according to any one of claims 1 to 3, comprising one or more selected members. Fixing raw material particles of sliding contact particles on the outer surface of the sliding member base,
Processing the raw material particles by a height of 20% or more and 30% or less with respect to the average particle diameter of the raw material particles to form a particle sliding contact surface,
The method for producing a sliding member, wherein the raw material particles have a particle size range of ± 20% of the average particle size of the raw material particles.   The method for manufacturing a sliding member according to claim 5, wherein the average particle diameter of the raw material particles is 10 µm or more and 250 µm or less.   The above-mentioned sliding contact particles, from the group consisting of diamond, diamond-like carbon, cubic boron nitride, glassy carbon, alumina, zirconia, silicon carbide, boron carbide, tungsten carbide, silicon nitride, silicide, phosphide, and sulfide The method for producing a sliding member according to claim 5, comprising one or more selected members.

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