JP6382147B2 - Sliding bearing device and pump equipped with the same - Google Patents

Description

  The present invention relates to a sliding bearing device using a resin material and a pump including the same, and more particularly to a sliding bearing device suitably used as a radial bearing of a rotary machine such as a pump and a pump including the same.

  In recent years, with the progress of urbanization, the heat island phenomenon has occurred due to the reduction of green spaces, the road surface becoming concrete, and the expansion of asphalt, and so-called guerrilla heavy rains frequently occur in urban areas. A large amount of local rainfall is introduced into the waterway without being absorbed into the ground on concrete and asphalt road surfaces. As a result, a large amount of rainwater flows into the drainage station in a short time.

  In order to prepare for the rapid drainage of a large amount of rainwater caused by such frequent torrential rains, drainage pumps installed in the drainage pump station should have rainwater before reaching the drainage pump station in order to prevent inundation damage due to delays in starting. Pre-standby operation to be started is performed.

  FIG. 1 is a partial schematic diagram of a vertical shaft pump that performs a prior standby operation. A vertical shaft pump 3 is disposed in the water tank 100 of the drainage station. The vertical shaft pump 3 includes an impeller 22 at the tip of the rotary shaft 10 arranged in the vertical direction, and causes the impeller 22 to suck air together with water. Thereby, the vertical shaft pump 3 can continue the operation (preceding standby operation) even if the water level of the water tank 100 is equal to or lower than the minimum operation water level LWL. This vertical shaft pump 3 is provided with a through hole 5 in the side surface of the suction bell 27 on the inlet side of the impeller 22, and an air pipe 6 having an opening 6 a in contact with outside air is attached to the through hole 5. ing. Thereby, in this vertical shaft pump 3, the supply amount of the air supplied into the vertical shaft pump 3 through the through hole 5 is changed according to the water level, and the drainage amount of the vertical pump 3 is controlled below the minimum operating water level LWL.

  FIG. 2 is a diagram for explaining the operating state of the preceding standby operation. For example, for large city rainwater drainage, a vertical shaft pump is started in advance according to rainfall information or the like regardless of the suction water level (A: air operation). As the water level rises from the low water level, the water level reaches the impeller position, and the vertical shaft pump is operated from the idling operation (air operation) to the agitating operation with the impeller (B: air / water agitation operation), and further through the through hole. Then, the operation proceeds to a full operation (D: steady operation) in which 100% water is discharged through an operation of gradually increasing the amount of water (C: air / water mixing operation) while sucking in air supplied through the water. When the water level drops from the high water level, the operation shifts from the full operation to the operation of gradually reducing the water amount while sucking in the air supplied through the through holes together with the water (C: air-water mixing operation). When the water level reaches near LLWL, the operation shifts to an operation (E: air lock operation) in which water is not sucked and drained. These five characteristic operations are collectively referred to as advance standby operation. The pump start is started from the water level LLLWL lower than the lower end of the casing.

  FIG. 3 is a cross-sectional view showing the entire vertical shaft pump 3 that performs the preceding standby operation shown in FIG. The through hole 5 and the air pipe 6 shown in FIG. 2 are not shown. As shown in FIG. 3, the vertical shaft pump 3 includes a discharge elbow 30 installed and fixed on the pump installation floor, a casing 29 connected to the lower end of the discharge elbow 30, and a lower end of the casing 29 and an impeller 22. And a suction bell 27 that is connected to the lower end of the discharge bowl 28 and sucks water.

A single rotating shaft 10 formed by connecting two upper and lower shafts to each other by a shaft coupling 26 is provided at substantially the center in the radial direction of the casing 29, the discharge bowl 28, and the suction bell 27 of the vertical shaft pump 3. Has been placed. The rotary shaft 10 is supported by an upper bearing 32 fixed to the casing 29 via a support member and a lower bearing 33 fixed to the discharge bowl 28 via a support member. An impeller 22 for sucking water into the pump is connected to one end side (suction bell 27 side) of the rotating shaft 10. The other end side of the rotating shaft 10 extends to the outside of the vertical shaft pump 3 through a hole provided in the discharge elbow 30 and is connected to a driving machine such as an engine or a motor (not shown) that rotates the impeller 22. A shaft seal 34 such as a floating seal, a gland packing, or a mechanical seal is provided between the rotary shaft 10 and a hole provided in the discharge elbow 30, and the water handled by the vertical pump 3 by the shaft seal 34 is supplied to the vertical pump. 3 is prevented from flowing out.

  The driving machine is installed on land so that maintenance and inspection can be easily performed. The rotation of the driving machine is transmitted to the rotary shaft 10 and the impeller 22 can be rotated. The water is sucked from the suction bell 27 by the rotation of the impeller 22, passes through the discharge bowl 28 and the casing 29, and is discharged from the discharge elbow 30.

  FIG. 4 is an enlarged view of a conventional bearing device applied to the bearings 32 and 33 shown in FIG. FIG. 5 is a perspective view of a plain bearing installed in the bearing device shown in FIG. As shown in FIG. 4, the conventional bearing device has a sleeve 11 made of stainless steel, ceramics, sintered metal, or surface-modified metal on the outer periphery of the rotating shaft 10. A sliding bearing 1 made of a hollow cylindrical resin material is provided on the outer peripheral side of the sleeve 11. The outer peripheral surface of the sleeve 11 faces the inner peripheral surface (slide surface) of the slide bearing 1 through a very narrow clearance, and is configured to slide with respect to the slide bearing 1. The slide bearing 1 is fixed to a support member 13 connected to a pump casing 29 (see FIG. 3) or the like via a collar portion 12a by a bearing case 12 made of metal or resin. As shown in FIG. 5, the sliding bearing 1 has a hollow cylindrical shape, the bearing sliding surface 1 a faces the outer peripheral surface of the sleeve 11, and the outer peripheral surface 1 b is fitted to the bearing case 12.

  The vertical shaft pump 3 shown in FIG. 3 is operated in the atmosphere when the pump is activated. That is, the bearings 32 and 33 are operated under dry sliding conditions without liquid lubrication. Here, the dry sliding condition refers to a condition in which the atmosphere of the bearings 32 and 33 during the pump operation is in the air without liquid lubrication, and the dry operation refers to operation under that condition. Further, the bearings 32 and 33 shown in FIG. 4 are also operated under drainage conditions in which water has passed through the bearings. Here, the drainage condition refers to a condition in which the atmosphere of the bearings 32 and 33 during the pump operation is in water mixed with foreign matter (slurry) such as earth and sand. Water mixing operation, full operation, air lock operation, etc. Bearings 32 and 33 are used under such conditions. In the vertical shaft pump 3 shown in FIG. 3, the two bearings 32 and 33 are arranged with respect to the rotary shaft 10. However, if the length of the rotary shaft 10 is increased, more bearings are provided accordingly. Be placed.

  A slide bearing device having a slide bearing using a resin material is widely used in rotating machines such as turbomachines and office machines because resin has good lubrication performance.

  As an evaluation method of a resin bearing, a friction coefficient and a wear amount of the resin are evaluated by rotating the disk-shaped resin in a state where the disk surface of the resin formed into a disk shape is pressed against a flat plate. Also, the friction coefficient and the wear amount of the resin are evaluated by reciprocating a piston using resin for the seal portion in the cylinder and sliding the seal portion and the cylinder. In such an evaluation method, there are few that reflect specific use conditions, and for example, there are not so many that assume that foreign matters are mixed during the sliding of the bearing.

Some rotary machines such as turbomachines use a resin material for a slide bearing for a radial bearing that receives a load acting in a direction perpendicular to the axial direction of the rotary shaft. A sliding bearing for a radial bearing used for a water pump is used by allowing pumping water to enter a gap (sliding portion) between a rotating body and a sliding bearing without using lubricating oil. For this reason, when the water pump handles foreign matter mixed water such as earth and sand (foreign matter mixed water), the foreign matter mixed water may enter the sliding surface (bearing sliding surface) of the sliding bearing. In this case, since the centrifugal force works in the radial direction of the slide bearing, it is difficult to discharge the foreign matter that has entered the gap between the rotating body and the slide bearing in the axial direction.

Since SiO ₂ , which is the main component of earth and sand (foreign matter), has higher hardness than the resin material, if the foreign matter enters the gap between the rotating body and the slide bearing, the resin material is worn. Therefore, in the operation of the water pump that handles foreign matter mixed water, there is a problem that the amount of wear of the slide bearing increases and the life of the slide bearing is shortened.

  Therefore, in many evaluation methods for resin bearings so far, evaluation of wear resistance under actual conditions is insufficient. Further, in many evaluation methods for resin bearings up to now, even if conditions assuming the inclusion of foreign matter are employed, these evaluation methods do not evaluate a slide bearing as a radial bearing. Therefore, in these evaluation methods, it is considered that foreign matter is easily released from the sliding surface to the outside, and the influence of the foreign matter staying on the sliding surface is small. For this reason, these evaluation methods are not suitable for the evaluation of the wear resistance performance of a sliding bearing as a radial bearing.

  In addition, the vertical shaft pump may be operated not only when the bearing sliding surface is in water, but also when the bearing sliding surface is exposed to the atmosphere, as in the preceding standby operation. Thus, when the vertical shaft pump is operated under a dry sliding condition in which the bearing sliding surface of the plain bearing is exposed to the atmosphere, a sliding bearing device having low friction under the dry sliding condition is required.

  On the other hand, in a vertical shaft pump using a conventional plain bearing made of a resin material, the bearing temperature may suddenly rise during dry operation and the operation may become impossible, and this increase in bearing temperature is a problem. 6A and 6B are schematic cross-sectional views showing the state of the rotary shaft 10, the sleeve 11, and the slide bearing 1 during pump operation. In the dry operation, the higher the rotation speed or the bearing load, the more the sliding bearing 1 used for the bearings 32 and 33 shown in FIG. 3 and the sleeve 11 attached to the rotating shaft 10 are in contact with each other. The frictional heat generated at the part increases. The frictional force may cause the sliding bearing 1, the rotary shaft 10, and the sleeve 11 to be locally hot. The hatched portion shown in FIGS. 6A and 6B is a portion where the slide bearing 1, the rotating shaft 10, and the sleeve 11 reach a high temperature.

  Due to the local high temperature of the sleeve 11 attached to the rotating shaft 10, as shown in FIG. 6A, the rotating shaft 10 may locally expand and the rotating shaft 10 may be bent slightly. As a result, vibration due to interference between the rotating body (rotating shaft 10 and sleeve 11) of the vertical shaft pump and the fixed body (slide bearing 1) and an increase in bearing load are likely to occur. That is, the rotating body and the fixed body come into contact with each other in the unbalanced direction of the rotating body, and when this contact portion generates heat, a temperature distribution is generated in the axial section of the rotating shaft 10, and the rotating shaft 10 bends due to partial thermal expansion. . At this time, since the center of gravity of the rotating body is shifted due to the bending of the rotating shaft 10, the unbalance of the entire rotating body gradually increases. Further, due to the bending of the rotating shaft 10, the contact mode between the rotating body and the slide bearing 1 may change, and the temperature gradient of the slide bearing 1 may change.

  Further, when the displacement due to the bending of the rotary shaft 10 becomes larger than the gap between the sleeve 11 and the slide bearing 1, as shown in FIG. 6B, the sleeve 11 and the slide bearing 1 come into contact at two points in opposite phases, Bending displacement is constrained. If the rotating shaft 10 continues to rotate in this state, thermal expansion continues and the pressing load on the slide bearing 1 increases. When the pressing load applied to the slide bearing 1 increases, the amount of heat generation increases. As the amount of heat generated increases, the thermal bending of the rotary shaft 10 is accelerated, and as a result, the pressing load applied to the slide bearing 1 further increases. In such a vicious circle, the temperature of the rotating shaft 10, the sleeve 11, and the sliding bearing 1 rises at an accelerated speed.

  Even if the unbalance amount of the rotating body is within the allowable value, if it is large, the surface pressure of the sliding bearing 1 increases, and the heat generation at the contact portion of the sliding bearing 1 with the rotating body increases. Therefore, the bending of the rotating shaft 10 is promoted, and the temperature of the sliding bearing 1 may increase at an accelerated speed. In order to reduce heat generation, it is effective to reduce the friction coefficient of the slide bearing 1. For this reason, there is a demand for a material for the sliding bearing 1 that has a lower friction than conventional ones.

JP 2001-173660 A JP 2006-249187 A JP 2012-251616 A

  The present invention has been made in view of the above-described circumstances. In a slide bearing device for a radial bearing used in a water pump, the bearing has a low-friction bearing slide surface even in a dry sliding condition, and in a foreign matter mixed water. An object of the present invention is to provide a plain bearing device having excellent wear resistance.

  According to one aspect of the present invention, a plain bearing device is provided. This sliding bearing device is a sliding bearing device provided with a sliding bearing, wherein the sliding bearing contains talc, aromatic polyetherketone, carbon fiber and unavoidable impurities, and the talc is on the sliding surface of the sliding bearing. The carbon fiber has an area ratio of 9% to 26%, and the aromatic polyether ketone and the inevitable impurities occupy the remaining area.

  According to another aspect of the present invention, the sliding bearing is configured to be operable in a state where the sliding surface is in contact with the atmosphere.

  According to another aspect of the invention, the aromatic polyether ketone is PEK, PEEK, PEKK or PEEKK.

  According to another embodiment of the present invention, the carbon fiber has a diameter of 5 μm or more and 10 μm or less.

  According to another embodiment of the present invention, the talc has a diameter of 0.1 μm or more and 15 μm or less.

  According to another aspect of the present invention, the sliding surface of the sliding bearing is configured to be operable in a state where the sliding surface is in contact with water mixed with earth and sand.

  According to another aspect of the present invention, the sleeve includes a sleeve that slides on a sliding surface of the sliding bearing, the sleeve has a Vickers hardness of 800 to 2500, and ceramics, cemented carbide, and Formed from any of the cermets.

  According to another aspect of the invention, a pump is provided. This pump includes the above-described sliding bearing device.

  ADVANTAGE OF THE INVENTION According to this invention, the slide bearing apparatus for radial bearings in a water pump provides a slide bearing apparatus that has a low-friction bearing slide surface even under dry sliding conditions and has excellent wear resistance in foreign matter-containing water. can do.

  In addition, according to the present invention, a slide bearing device is used in an air atmosphere in which there is no water on the bearing slide surface by using a composite material of carbon fiber, talc, and aromatic polyether ketone for the slide bearing. Even in the case, low friction can be secured.

  Further, according to the present invention, by using a composite material of carbon fiber, talc, and aromatic polyether ketone for a slide bearing, even when the slide bearing device is used in water contaminated with foreign matter such as earth and sand, Wear of the bearing material can be suppressed.

  Further, according to the present invention, by combining the material of the slide bearing so that the area ratio of the carbon fiber, talc, and aromatic polyether ketone on the slide surface of the slide bearing becomes a predetermined ratio, the low in dry operation is achieved. Friction can be ensured, and anti-slurry wear in foreign matter-mixed water can be ensured.

It is a partial schematic diagram of a vertical shaft pump that performs a preliminary standby operation. It is a figure explaining the driving | running state of a prior | preceding standby driving | operation. It is sectional drawing which shows the whole vertical shaft pump which performs the prior | preceding standby operation | movement shown in FIG. It is an enlarged view of the conventional bearing device applied to the bearing shown in FIG. It is a perspective view of the slide bearing installed in the bearing apparatus shown in FIG. It is typical sectional drawing which shows the state of the rotating shaft at the time of pump operation, a sleeve, and a slide bearing. It is typical sectional drawing which shows the state of the rotating shaft at the time of pump operation, a sleeve, and a slide bearing. It is a graph which shows the evaluation result of the abrasion loss in an evaluation test.

  The slide bearing device according to the present embodiment has the same structure as the slide bearing device shown in FIG. 4, for example. That is, the sliding bearing device according to the present embodiment includes the rotating shaft 10 and the sleeve 11 that are rotating bodies, and the sliding bearing 1 that is a fixed body. Further, the slide bearing 1 used in the slide bearing device according to the present embodiment has the same structure as the slide bearing 1 shown in FIG.

  On the other hand, the plain bearing 1 according to the present embodiment is composed of a composite material of carbon fiber, talc, aromatic polyether ketone, and inevitable impurities. The inner peripheral surface of the cylindrical slide bearing 1 constitutes a bearing slide surface 1 a that contacts the outer peripheral surface of the sleeve 11. That is, the plain bearing 1 is composed of a material having carbon fiber, talc, and aromatic polyether ketone that impart low friction, high strength, and wear resistance.

  The aromatic polyether ketone includes at least one of PEK (polyether ketone), PEEK (polyether ether ketone), PEKK (polyether ketone ketone), and PEEKK (polyether ether ketone ketone). Carbon fibers are composed of short fibers.

The inventors of the present invention have focused on the fact that an important factor affecting the low friction property and the wear resistance is the area ratio of carbon fiber, talc, and aromatic polyether ketone on the bearing sliding surface 1a. That is, when the area ratio of carbon fiber, talc, and aromatic polyether ketone is a predetermined ratio, the present inventors have a low friction coefficient and good moldability and wear resistance. I found out.

Table 1 shows the results of calculating the area ratio (%) of carbon fiber, talc, and aromatic polyether ketone in the sliding bearing 1 used in the sliding bearing device according to the present embodiment. The area ratio is obtained by photographing the bearing sliding surface 1a with a microscope and analyzing the image of the observed portion. For carbon fiber, a plane having an area of 24000 μm ² was used as an observation part, and for talc, a plane having an area of 2450 μm ² was used as an observation part. There were 10 observation positions for each material.

Summarizing the area ratio (%) of each material at the observation positions 1 to 10 shown in Table 1, the area ratio of carbon fiber is 9.0% to 26.0%, and the area ratio of talc is 7.0% to 13 0.0% or less. Further, when the diameter and length of the carbon fiber observed on the bearing sliding surface 1a were measured, the diameter was 5 μm or more and 10 μm or less, and the length was 5 μm or more and 1000 μm or less. Further, when the diameter of talc observed on the bearing sliding surface 1a was measured, it was 0.1 μm or more and 15 μm or less. Although not shown in Table 1, the plain bearing 1 includes unavoidable impurities in addition to carbon fiber, talc, and aromatic polyether ketone.

Hereinafter, the Example of the resin material used for the slide bearing 1 of the slide bearing apparatus which concerns on this invention is described. In Example 1, resin test pieces (molded articles) containing carbon fiber, talc, aromatic polyether ketone, and inevitable impurities were prepared so as to have the area ratios shown in Table 2, respectively, and the moldability and friction coefficient Evaluation was performed. Here, the area ratio is a minimum value and a maximum value obtained by providing a smooth surface on the molded product, photographing 10 places on the surface with a microscope, and analyzing the area of each material in the area of the observed portion by image analysis. It is. Incidentally, carbon fibers and viewing portion plane having an area of 24000Myuemu ^2, talc was observed partial plane having an area of 2450μm ^2. In Table 2, only the area ratios of carbon fiber and talc are described, but the remaining area is occupied by aromatic polyether ketone and inevitable impurities.

  In the evaluation of moldability, it was evaluated whether or not pores were generated by molding by a special method in which a pellet-shaped resin raw material was heated and baked and solidified in a mold. In the evaluation of the friction coefficient, a 20 × 20 × 5 (mm) resin test piece was pressed against a φ20 cylindrical test piece made of cemented carbide with a load of 500 g, and the cemented carbide was cemented at a peripheral speed of 0.5 m / s for 30 minutes. Slide against the alloy. Lubricating oil is not used. Regarding the quality of the evaluation of the friction coefficient, the case where the friction coefficient is larger than that of the commercially available PEEEK composite material and the PBI (registered trademark) composite material which are excellent in heat resistance is indicated as x, and the case where the friction coefficient is small is indicated as ◯. In addition, as a comprehensive evaluation, the ones with good formability and friction coefficient were accepted.

  As shown in Table 2, the area ratio of each component on the surface of the molded product for which a pass evaluation was obtained was 9% to 26% for carbon fiber and 7% to 13% for talc. That is, the resin material having the area ratio of carbon fiber, talc, and aromatic polyether ketone in the slide bearing 1 according to the present embodiment was able to obtain a pass evaluation.

  Next, the sliding bearing 1 used in the sliding bearing device according to the present embodiment (this embodiment) under dry sliding conditions in which neither a lubricating oil nor water intervenes in the sliding portion that is a gap between the bearing sliding surface 1a and the sleeve 11. The friction coefficient of the sliding bearing 1 when the sleeve 11 was slid with respect to the product) was evaluated. In addition, as a comparative example, the friction coefficient is similarly evaluated for a resin test piece (molded product) manufactured using a PEEK-based composite material and a PBI-based composite material that are excellent in heat resistance, which are conventionally used. went.

  In the evaluation test in Example 2, with respect to a bearing having a bearing inner diameter of 65 mm and a bearing width of 20 mm made of the above three kinds of resin materials under a dry sliding condition in which a liquid film such as a water film or an oil film is not present on the sliding portion. The coefficient of friction when the sleeve 11 of the rotating shaft 10 was slid for 2 hours was measured and evaluated. The radial bearing surface pressure (bearing load / (bearing inner diameter × bearing width)) at this time was 0.1 MPa, and the sliding speed was 4.0 m / sec. Table 3 shows the evaluation results of the friction coefficient in the evaluation test of Example 2.

  As shown in Table 3, it can be seen that the present product exhibits a friction coefficient that is 29% to 33% smaller than that of a conventional material bearing, and exhibits a very good dry sliding effect. In addition, the diameter of the carbon fiber added in the resin material of the present product in Example 2 is 5 μm or more and 10 μm or less, and the diameter of talc is 0.1 μm or more and 15 μm or less. Here, the diameter of talc refers to the diameter of talc particles.

Next, a sliding test was performed in foreign matter-mixed water for each bearing formed of the same material as that shown in Example 2, PEEK-based composite material, and PBI-based composite material. Abrasion resistance was evaluated. Each bearing has a bearing inner diameter of 65 mm and a bearing width of 20 mm. In the sliding test, each bearing was poured into water having a foreign matter concentration of 3000 mg / L, and the rotating shaft was slid on each bearing for 8 hours. The radial bearing surface pressure at this time was 0.12 MPa, and the sliding speed was 5.0 m / sec. Foreign matter contained in water contains silica sand (main component: SiO ₂ ) having an average particle diameter of about 5 μm and silica sand having an average particle diameter of about 30 μm in a ratio of 1: 1. Table 4 shows the evaluation results of the wear rate in the evaluation test of Example 3.

  As shown in Table 4, it can be seen that the resin material of this embodiment exhibits a wear amount that is 60% to 76% smaller than that of the conventional material and exhibits very good wear resistance.

  From the results shown in Table 3 of Example 2 and Table 4 of Example 3, the following can be understood. That is, the friction coefficient in the air of the material of the slide bearing 1 according to the present embodiment is 29% to 33% smaller than the friction coefficient of the conventional material. Further, the wear rate of the material of the slide bearing 1 according to the present embodiment in the foreign matter mixed water is 60% to 76% smaller than the wear rate of the conventional material. As described above, the material of the slide bearing 1 according to the present embodiment is superior to the conventional material both in the air and in the foreign matter mixed water.

Next, when the hardness of the sleeve 11 that slides relative to the sliding bearing 1 according to the present embodiment is changed, a sliding test is performed on the sleeve 11 and the sliding bearing 1 in foreign matter-mixed water, The wear resistance of the slide bearing 1 and the sleeve 11 was evaluated. The slide bearing 1 has a bearing inner diameter of 65 mm and a bearing width of 20 mm. In the sliding test, the sliding bearing 1 was put into water having a foreign matter concentration of 3000 mg / L, and the rotating shaft 10 and the sleeve 11 were slid on the sliding bearing 1 for 8 hours. The radial bearing surface pressure at this time was 0.12 MPa, and the sliding speed was 5.0 m / sec. Foreign matter contained in water contains silica sand (main component: SiO ₂ ) having an average particle diameter of about 5 μm and silica sand having an average particle diameter of about 30 μm in a ratio of 1: 1.

  FIG. 7 shows the evaluation result of the wear amount in the evaluation test of Example 4. As shown in FIG. 7, in the range where the Vickers hardness of the sleeve 11 is less than 800, the wear resistance of the sliding bearing 1 and the sleeve 11 is improved as the Vickers hardness of the sleeve 11 is increased. On the other hand, when the Vickers hardness of the sleeve 11 is 800 or more, the wear rate of the slide bearing 1 and the sleeve 11 is minimized and becomes almost constant. This is because, when the hardness of the sleeve 11 is lower than that of a foreign substance such as sand, the friction coefficient of the sliding surface of the sleeve 11 increases due to abrasive wear caused by the foreign substance, and the aggression (friction force) against the sliding bearing 1 increases. is there. The Vickers hardness of foreign matters such as sand is about 800. When the sleeve 11 has a Vickers hardness of 800 or more, the sliding surface of the sleeve 11 is not roughened, so that the wear rate of the sliding bearing 1 and the sleeve 11 is minimized, and good wear resistance is exhibited.

  As described above, in order for the slide bearing 1 and the sleeve 11 used in the slide bearing device of the present embodiment to exhibit good wear resistance in foreign matter-mixed water, the sleeve 11 may have a Vickers hardness of 800 or more. preferable. In addition, a material having a Vickers hardness exceeding 2500 is generally not used as the sleeve 11. For this reason, the upper limit of the Vickers hardness of the sleeve 11 is 2500. Therefore, the sliding bearing device according to the present embodiment exhibits very excellent wear resistance in foreign matter-mixed water by combining the sliding bearing 1 and the shaft sleeve having a Vickers hardness of 800 or more and 2500 or less.

  Finally, the carbon fiber area ratio used in the evaluation test of Example 1 is 9% or more and 26% or less, the talc area ratio is 7% or more and 13% or less, and the aromatic polyether ketone and inevitable impurities are the remaining area. An experiment was conducted on the sliding bearing 1. Specifically, the sliding bearing 1 is used for the bearings 32 and 33 which are radial bearings of the vertical mixed flow pump shown in FIG. 3, and the drainage operation and the dry operation of water containing actual foreign matters (earth and sand) are repeated. It was.

  The sleeve 11 provided on the outer periphery of the rotary shaft 10 of the vertical mixed flow pump has a Vickers hardness (Hv) of 800 or more and 2500 or less, and is made of ceramic, cemented carbide, or cermet. The outer peripheral surface of the sleeve 11 slides with the sliding surface 1 a of the sliding bearing 1.

As a result of repeating the drainage operation and the dry operation, the wear rate of the slide bearing 1 is the conventional PEE.
Compared to the wear rate of the sliding bearing using K resin, it decreased to a quarter. In conventional plain bearings using PEEK resin, a sudden increase in bearing temperature may occur in a short time during dry operation, and the pump operation may be stopped. On the other hand, in the slide bearing 1, a rapid temperature rise did not occur, and the pump could be operated stably. That is, by using the slide bearing 1 for the bearings 32 and 33 used under severe conditions in which the drainage operation and the dry operation are repeatedly performed, excellent bearing characteristics are exhibited both in the air and in foreign matter-containing water. .

  As described above, if the pump is provided with the slide bearing 1 of the slide bearing device according to the present embodiment as a radial bearing, the underwater operation and the atmospheric operation are repeated in the drainage station that processes the foreign matter mixed water. However, the wear of the slide bearing 1 can be suppressed, and the low friction property (lubricity) of the slide bearing 1 can be maintained.

  The slide bearing device according to the present embodiment can be used for a slide bearing device as a radial bearing that is operated in an atmospheric operation and a slide bearing device as a radial bearing that is operated in water mixed with foreign matter. Further, the sliding bearing device according to the present embodiment can be used for a sliding bearing device as a radial bearing in which an operation in water in which foreign matter is mixed and an operation in the atmosphere are repeated.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. Note that any shape or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are achieved.

DESCRIPTION OF SYMBOLS 1 ... Slide bearing 3 ... Vertical shaft pump 10 ... Rotary shaft 11 ... Sleeve

Claims (8)

A sliding bearing device having a sliding bearing,
The plain bearing includes talc, aromatic polyether ketone, carbon fiber and inevitable impurities,
In the sliding surface of the sliding bearing, the talc has an area ratio of 7% to 13%, the carbon fiber has an area ratio of 9% to 26%, the aromatic polyether ketone and the inevitable A plain bearing device in which impurities occupy the remaining area.   The sliding bearing device according to claim 1, wherein the sliding bearing device is configured to be operable in a state where a sliding surface of the sliding bearing is in contact with the atmosphere.   3. The plain bearing device according to claim 1, wherein the aromatic polyether ketone is PEK, PEEK, PEKK, or PEEKK.   4. The plain bearing device according to claim 1, wherein the carbon fiber has a diameter of 5 μm to 10 μm.   5. The plain bearing device according to claim 1, wherein the talc has a diameter of 0.1 μm to 15 μm.   The sliding bearing device according to any one of claims 1 to 5, wherein the sliding surface of the sliding bearing is configured to be operable in a state where the sliding surface is in contact with water mixed with earth and sand. A sleeve that slides on the sliding surface of the sliding bearing;
The plain bearing device according to any one of claims 1 to 6, wherein the sleeve has a Vickers hardness of 800 or more and 2500 or less, and is formed of any one of ceramics, cemented carbide, and cermet. .   A pump comprising the plain bearing device according to any one of claims 1 to 7.

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