JP2012132548A - Slide bearing combination slide member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of nonexistence of a slide member combination capable of intermittent unlubricated sliding for a long period of time and sliding in a liquid, a gas and a gas-liquid mixture fluid containing slurry such as earth and sand in the slide member combination of a slide bearing for use in a rotary machine.SOLUTION: As a slide bearing combination slide member operated in an unlubricated condition and in the fluid containing the slurry, a bearing stationary side slide member is made of a metal with a great coefficient of thermal expansion with its internal sliding surface having a structure wherein a passage for cooling liquid is not provided. In a rotation shaft sleeve side slide member, a carbon fiber fabric material as a carbon material with a bulk ratio of at least 50% is used so as to form layers in the direction of a rotation shaft by means of laminate molding, and a carbon fiber fabric lamination carbon-based composite material with a small coefficient of expansion is used wherein the end surface of carbon fiber is exposed on the slide surface. The problem is solved as described above.

Description

  The present invention relates to a sliding bearing combined sliding member used in a rotating machine, in sliding in a slurry such as water and earth and sand while preventing a phenomenon of holding the bearing in the air and heat generation during non-lubricating operation. The present invention relates to a sliding bearing combined sliding member that prevents solid particles such as earth and sand, which are the main causes of bearing wear, from entering the bearing gap.

  A conventional sliding bearing combined sliding part shape will be described with reference to FIG. The sliding surface of the sliding bearing includes a rotating shaft sleeve side sliding member 2 fitted and fixed to the rotating shaft 1, and a fixed bearing side sliding member that allows the rotating shaft sleeve side sliding member 2 to be rotatably slidably fitted. 3, and a cooling fluid passage groove 4 is provided in the fixed bearing side sliding member 3.

  The cooling fluid passage groove 4 on the sliding surface of the fixed bearing side is indispensable for supplying the lubricating liquid to the sliding surface and cooling the sliding member to prevent the heat generated during the sliding operation of the sliding bearing. However, in the conventional sliding bearing combination, the cooling fluid passage groove 4 is provided with the cooling fluid passage groove 4 formed by processing the sliding surface of the cylindrically integrated fixed bearing side sliding member, or as shown in FIG. In such a system in which the divided sliding members 5 are arranged on the inner circumference, the distance between the sliding members and the gap 6 are adjusted.

Taking a pump as an example of a rotating machine, a cooling fluid passage groove is arranged facing the sliding surface on the fixed bearing side of a sliding bearing in a pump operation that handles a gas-liquid mixed fluid containing solid particles such as earth and sand in the load liquid. If so, the solid particles flowing from the cooling fluid passage groove that is continuous with the clearance between the sliding surfaces cause foreign matter biting on the sliding surface, and wear of the sliding surface becomes significant.
For this reason, a hard material such as ceramics is indispensable for the sliding surface material in order to suppress wear, but there is a drawback that it is extremely vulnerable to various impacts due to brittleness due to the hard material.

  In a sliding bearing with an extremely smooth sliding surface on the premise of fluid lubrication, if a fluid film is formed on the sliding surface without interruption, it has extremely stable sliding characteristics, but contains solid particles. When sliding operation is performed in a gas-liquid mixed fluid, there is a shortage of cooling lubricant due to clogging of solid particles in the gas-liquid mixed fluid in the piping that supplies the cooling lubricant to the bearing sliding part, or the fixed bearing side Due to the hard solid particles that have entered the bearing gap between the sliding surface and the sliding surface on the rotating shaft sleeve side, the fluid film governing lubrication on the sliding surface is lost, and the fixed bearing side sliding member and the rotating shaft side sleeve side The sliding member causes direct contact, causing abnormal wear of the sliding surface due to solid particles, and excessive thermal expansion of the rotating shaft due to abnormal heat generation due to insufficient cooling, causing the sliding surface on the fixed bearing side and the sliding surface on the rotating shaft sleeve side. The bearing gap, which is the gap between Then, is not it even less to lose completely the bearing function and eventually secured the two sliding surfaces.

  As described above, in the sliding bearing, it is necessary to suppress the heat generation on the bearing sliding surface which is a cause of destruction. Suppression of heat generation is achieved by improving the processing accuracy to achieve a low coefficient of friction to reduce the heat generated by sliding between the sliding surface on the fixed bearing side and the sliding surface on the rotary shaft sleeve, and sliding body material Therefore, it is necessary to improve the lubrication capacity by selecting the combination of these and to enhance the cooling capacity to quickly remove the generated heat.

  A cooling fluid passage groove provided on the sliding surface plays a major role in improving the lubrication capacity and cooling capacity of the slide bearing. The larger the flow path cross-sectional area of the cooling fluid passage groove, the more cooling fluid can be supplied to the sliding surface and the cooling effect is improved, but foreign particles inclusions of solid particles such as earth and sand on the bearing sliding surface As a result, there is a defect that the bearing sliding surface is severely worn.

  Furthermore, in the combination of sliding members in conventional sliding bearings, it is a collapsible material having self-lubricating properties for bearing sliding members in order to supply graphite particles, which are self-lubricating substances, for the purpose of improving lubricating sliding characteristics. A metal shaft sleeve / graphite bearing using graphite has been proposed.

  However, in this combination, even if it can be used to some extent due to the effect of graphite particles, which are solid lubricating components supplied from graphite bearings under non-lubricated conditions, sliding operation under long-term non-lubricated conditions is possible. In this case, it is difficult to suppress the expansion of the outer diameter due to the large linear expansion coefficient of the metal that is the sliding member on the rotating shaft sleeve side. Under certain conditions, foreign matter, solid particles, etc. from the cooling fluid passage groove provided on the sliding bearing sliding surface are caught, and the sliding surface on the graphite bearing side, which is a collapsible material, is significantly worn and damaged by the sediment wear phenomenon. .

  On the other hand, even in the case of cemented carbide shaft sleeve / ceramic bearing, which is a representative example of a combination sliding member using a super hard material among sliding member combinations in a conventional sliding bearing, the slurry mixing condition Even if it can be used under unlubricated conditions for a short time and for a very short period of time, it will not break due to hugging caused by abnormal expansion due to sliding heat generation of the cemented carbide shaft sleeve caused by unlubricated conditions for a long time, or no Ensuring stable operation of a rotating machine using a sliding bearing, in which a sliding member heated to a high temperature is subjected to a thermal shock caused by a sudden inflow of coolant to the sliding member that has become hot due to a lubrication operation. Had a fatal problem.

  In particular, when a super hard material such as cemented carbide is used for the rotating shaft sleeve side sliding member as an integral structure, the bearing clearance caused by heat generation and expansion of the rotating shaft sleeve side sliding member due to non-lubricated sliding of the sliding bearing The rotating shaft sleeve side sliding member is broken and the rotating shaft sleeve side sliding member is broken or the metal shaft having a large linear expansion coefficient holding and fixing the rotating shaft sleeve is thermally expanded. Due to this, the cylindrical rotary shaft sleeve side sliding member is broken due to tensile breakage, causing a sudden loss of shape of the rotary shaft sleeve side sliding member, which is different from normal wear that gradually proceeds according to the sliding time, There was a problem that the function as a sliding bearing was lost and it could not be used at all.

  In general, in order to ensure wear resistance under non-lubricated sliding conditions and slurry conditions and to suppress sliding heat generation, the combined sliding member uses a high hardness wear resistant material to make the surface condition on the sliding surface very smooth However, if a high hardness material with an integral structure is used for the fixed bearing side sliding member and the rotary shaft sleeve side sliding member, the material will suddenly break due to brittleness, which is a characteristic of the high hardness material. The problem has not been solved.

  In addition, an example of using a composite material that dislikes sudden brittle fracture of ceramic materials and instead has a fiber reinforced in the rotational direction on the sliding member on the fixed bearing side has been studied. Although there is an improvement, when non-lubricated sliding is performed, if the non-lubricated sliding time is long, the bearing may be held due to thermal expansion of the sliding member on the rotating shaft sleeve side, or even if the non-lubricated sliding time is short. Precipitation, peeling, and dropping of the reinforcing fiber material, which is a sliding member on the fixed bearing side, occur, and the sliding surface properties cannot be stabilized by the sliding time, leaving many problems for stable operation of the rotating machine. It is in a situation and has not yet been fulfilled. In addition, although the prior literature was investigated, the thing similar to this invention was not found.

  The problem to be solved is a sliding that enables both long-time non-lubricated sliding and sliding operation in a liquid containing slurry such as earth and sand in a combination sliding member in a sliding bearing used in a rotating machine. Even in the combination sliding member of hard materials that do not have a bearing combination sliding member and enable non-lubricated sliding for a short time, due to a sudden hug and a sudden fluctuating load due to a sudden inflow of coolant, There is a drawback that there is no method for preventing the loss of the function of the sliding bearing at a stretch due to the significant breakage of the material forming the sliding bearing.

  Therefore, in order to delay the hugging due to the temperature rise, which is a major factor of the sliding bearing failure, the outer diameter expansion of the rotating shaft sleeve side sliding member is kept low, and further, it is a major cause of sliding heat generation in the sliding portion. By preventing the intrusion of foreign matter, solid particles, etc. into the bearing gap, it has stability of the sliding surface property against long-term sliding including unlubricated sliding, and also accompanying sudden changes in sliding environment There is a need for a sliding bearing combined sliding member that does not cause significant breakage, but none satisfies it.

  The object of the present invention is that a sliding bearing combined sliding member used in a gas, a liquid containing solid particles such as earth and sand, and a gas-liquid two-phase fluid is used under these non-lubricating conditions and a high temperature state. A sliding bearing combined sliding member that maintains stable sliding characteristics even under thermal shock load conditions due to rapid cooling liquid inflow and does not cause excessive wear even in cargo liquids containing a large amount of solid particles such as earth and sand. Especially for vertical shaft pumps, it is a submersible bearing that is premised on lubrication by load fluid, and a pump that requires volatile load fluid lubrication that can change its state in the vicinity of the bearing, and an intentional advance An object of the present invention is to provide a sliding bearing combined sliding member that exhibits good sliding characteristics even in a pump that performs standby idle operation and that exhibits stable sliding characteristics even in a slurry liquid such as earth and sand.

  In order to achieve the above object, the invention according to claim 1 is a combined sliding member in a sliding bearing used in a liquid containing solid particles and bubbles, in a gas-liquid mixed fluid, or in an air in which no liquid exists. As shown in FIG. 3, the fixed shaft side sliding member 8 is a metal member having a large thermal expansion coefficient, and the sliding surface 7 has no passage groove for cooling liquid containing solid particles and bubbles. The rotary shaft sleeve side sliding member 9 formed with a completely continuous surface not provided and fitted to the fixed shaft side sliding member 8 so as to be freely rotatable and slidable has a smaller thermal expansion coefficient than that of metal. A sliding bearing combined sliding member characterized by using a carbon material occupying a volume ratio of 50% or more.

  The invention according to claim 2 is the sliding bearing combination sliding member according to claim 1, wherein, as shown in FIG. 4, the flow of cooling fluid in the gas-liquid mixture containing solid particles for bearing cooling is provided. The slide bearing combined sliding member is characterized in that the path 10 is regularly arranged near the back surface of the sliding surface 7 of the sliding bearing fixed shaft side sliding member 8.

  The invention according to claim 3 is the sliding bearing combined sliding member according to claim 1 and claim 2, wherein the sliding surface 7 of the sliding bearing fixed shaft side sliding member 8 as shown in FIG. In order to improve the wear resistance of the sliding surface 7, the sliding surface 7 of the metal material constituting the sliding bearing fixed shaft side sliding member 8 is plated, sprayed, or vapor deposited. The sliding bearing combined sliding member is characterized in that the high-hardness coating 11 is formed by nitriding or the like and the sliding surface 7 is hardened.

  The invention according to claim 4 is the sliding bearing combination sliding member according to any of claims 1 to 3, wherein, as shown in FIG. 6, the rotating shaft sleeve side sliding member used for the sliding bearing combination 9 is a carbon material occupying a volume ratio of 50% or more, and a net-like carbon fiber cloth material 12 is laminated and molded in the direction of the rotation axis, and the carbon fiber end face 14 is exposed on the sliding surface 13 thereof. The carbon fiber end face 14 on the sliding surface 13 and the carbon material 15 as a composite structure with carbides 15a and 15b are provided with various sliding characteristics by vapor deposition or salt bath impregnation. The sliding member is a sliding member combined with a characteristic sliding bearing.

In the conventional sliding bearing combination sliding member, as the stationary bearing side sliding member, cemented carbide, silicon nitride (Si ₃ N ₄ ), silicon carbide (SiC), tungsten carbide (WC), alumina (Al ₂ The fixed bearing side sliding member using any one of ceramics of O ₃ ), chromia (CrO ₂ , Cr ₂ O ₃ ), and zirconia (ZrO ₂ ) has high hardness and high corrosion resistance, but is combined with the rotation. When cemented carbide or ceramic sprayed metal is used as the sliding member on the shaft sleeve side, sliding characteristics due to changes in the sliding surface properties accompanying the occurrence of adhesive wear due to local contact between the hard materials under non-lubricated sliding A hug phenomenon due to loss of the bearing clearance due to thermal expansion of the rotating shaft sleeve side sliding member due to a drastic change in temperature, abnormal temperature rise of the rotating shaft sleeve side sliding member, Occurrence of fracture of the rotating shaft sleeve sliding part due to the tensile stress load on the rotating shaft sleeve side sliding member due to thermal expansion of the metal rotating shaft holding and fixing the rotating shaft sleeve side sliding member, or continuous non-lubricated sliding Although there was a problem such as a thermal shock destruction due to a rapid temperature drop of the sliding member heated to a high temperature due to a rapid inflow of the coolant immediately after, such a problem can be reliably solved at low cost. .

Conceptual diagram of conventional sliding bearing combination sliding part shape Schematic diagram of sliding part combination sliding part shape adopting split type sliding member Exploded view of sliding bearing combination sliding member showing the first embodiment of the present invention The conceptual diagram of the sliding bearing combination sliding member which shows 2nd Embodiment of this invention. Exploded view of sliding bearing combination sliding member showing a third embodiment of the present invention. The conceptual diagram of the sliding bearing combination sliding member which shows 4th Embodiment of this invention. A first conceptual view of the fixed bearing side in which the fixed bearing side is divided and a passage for cooling fluid is provided Second conceptual diagram of the fixed bearing side in which the fixed bearing side is divided and a passage for cooling fluid is provided. Cross section of a centrifugal pump using a combination plain bearing Cross-sectional view of a vertical mixed flow pump using a combined plain bearing Partially cut side view of a sliding bearing sliding test apparatus for demonstrating the effectiveness of the present invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 3 is a development view of the sliding bearing combination sliding member according to the first embodiment of the present invention. In this combination, the fixed bearing side sliding member 8 made of a metal having a large thermal expansion coefficient, characterized in that it has no flow passage for passing a cooling fluid on the sliding surface 7 of the fixed bearing side sliding member, and the volume ratio And a carbon fiber laminated carbon composite material in which the carbon fiber cloth material 12 is laminated and molded in the direction of the rotation axis and the carbon fiber end face 14 is exposed on the sliding surface. The rotating shaft sleeve side sliding member 9 is used.

When the stainless steel SUS316 is seen as the fixed shaft side sliding member 8 used here, its thermal expansion coefficient is 16.1 × 10 ⁻⁶ / ° C., and the carbon fiber cloth material is laminated and molded in the direction of the rotation axis. The rotary shaft sleeve side sliding member 9 with the carbon fiber end face exposed on the surface has a thermal expansion coefficient in the radial direction of 0.8 to 1.1 × 10 ⁻⁶ / ° C., and a 15 to 20 times opening therebetween. However, since the rotary shaft sleeve is fitted and fixed to the metal rotary shaft 1, the rotary shaft sleeve is affected by the thermal expansion of the metal rotary shaft 1. Therefore, the metal rotary shaft 1 and the carbon fiber laminated carbon composite material are used. It is necessary that the thermal expansion amount of the entire rotary shaft including the manufactured rotary shaft sleeve side sliding member 9 does not exceed the thermal expansion amount of the fixed shaft side sliding member 8.

  For this reason, what should be considered when determining the thickness of the rotating shaft sleeve side sliding member 9 is the temperature rise values of the fixed shaft side and the rotating shaft side both sliding members in the usage state of the bearing. The temperature of the sliding member during the bearing operation is affected by the heat capacity of the member and the heat radiation path determined by the structure, and the temperature increase value of the rotary shaft sleeve side sliding member 9 is generally due to structural restrictions in the sliding bearing, Since it is confirmed that the temperature rise value of the fixed shaft side sliding member 8 is two to three times as large as that of the fixed shaft side sliding member 8, the non-lubricated sliding time and the expansion amount of each of the fixed bearing side and the rotary bearing side in the assumed use of the bearing In consideration of the estimation, the fitting allowance between the metal rotating shaft 1 and the rotating shaft sleeve side sliding member 9, the elastic modulus of the sliding member, etc., and the thickness of the rotating shaft sleeve side sliding member 9 and other dimensions The specifications will be determined.

  This sliding bearing combination sliding member using a carbon fiber laminated carbon-based composite material for the metal fixed bearing side sliding member 8 and the rotary shaft sleeve side sliding member 9 of the present invention is compared with the combination of the conventional example. Even if a dimensional change due to heat generation occurs due to a long-time sliding operation including non-lubricating sliding, as described above, the increase in the inner diameter of the fixed bearing side sliding member 8 is caused by the rotation shaft sleeve side sliding. In order to exceed the expansion of the outer diameter of the moving member 9, the hugging phenomenon that leads to loss of function in the sliding bearing is not reached.

  The next feature of the present invention is that a cooling fluid passage groove or flow which is indispensable for bearing cooling is provided on the sliding surface 7 of the fixed bearing side sliding member 8 in order to ensure wear resistance against sediment wear under slurry conditions. The path is to be secured at a place other than the groove on the fixed bearing side sliding surface. In general sliding bearings, a very hard material is used for the fixed bearing side sliding member 8 and the rotating shaft sleeve side sliding member 9, and the sliding surface is made very smooth and the fluid film for controlling lubrication is stable. In the sliding bearing of the present invention, the lubricity of the graphite material occupying a volume ratio of 50% or more used for the rotating shaft sleeve side sliding member 9 without depending on the lubrication of the sliding surface by the fluid film. Is to be used.

  Furthermore, in order to use a brittle graphite material under slurry conditions in which wear easily proceeds, between the sliding surface 7 of the fixed bearing side sliding member 8 and the sliding surface of the rotary shaft sleeve side sliding member 9, It is characterized by not having a cooling fluid passage groove so that solid particles that promote wear do not enter.

  As a reinforcing form of the carbon fiber in the carbon fiber laminated carbon composite material used as the rotating shaft sleeve side sliding member 9, the carbon fiber end face 14 is formed on the sliding surface 13 by laminating and molding the carbon fiber material 12 in the rotating shaft direction. Forms other than the carbon fiber reinforced carbon composite material with exposed carbon, for example, carbon fiber reinforced carbon composite material with the carbon fiber side surface exposed on the sliding surface surface formed by rolling up the carbon fiber in the rotational direction and sliding the fixed bearing side The combination sliding member combined with cemented carbide or ceramics as the moving member cannot stably ensure the sliding surface property of the rotating shaft sleeve side sliding member accompanying the long-term sliding, and the sliding bearing breaks down. In addition, the carbon fiber end face 14 is dispersedly exposed on the entire sliding surface on the rotating shaft sleeve side on the sliding surface 13 of the rotating shaft sleeve side sliding member 9 in order to proceed rapidly. It is mandatory.

The linear expansion coefficient that governs the thermal expansion of the carbon fiber laminated carbon composite material is 0 even if the carbon fiber laminated carbon composite material is subjected to surface treatment or includes a composite material by metal impregnation. 0.8 to 1.3 × 10 ⁻⁶ / ° C., which is much smaller than the coefficient of thermal expansion of 7.4 to 8.4 × 10 ⁻⁶ / ° C. when the fiber is wound around the outer periphery of the cylinder.

  For this reason, when the sliding member on the rotating shaft sleeve side formed by winding the carbon fiber material around the outer periphery of the cylinder is combined, the bearing clearance is greatly reduced due to heat generated during the non-lubricating sliding operation. It can be seen that there is a high possibility of the moving surface sticking.

  When the carbon fiber laminated carbon-based composite material is used on the rotary shaft sleeve side, the carbon fiber end face 14 is formed in a discontinuous manner so that the sliding surface can be locally moved by a non-lubricated sliding operation. Even if the adhesion phenomenon is limited to a local phenomenon and the carbon fiber end face of the rotating shaft sleeve side sliding surface 13 is damaged due to earth and sand wear that occurs under slurry conditions, the new carbon fiber end face 14 becomes a sliding face. The use of a high-hardness material having a smooth sliding surface with a conventional integral structure in that the stability of the sliding surface state due to exposure can be ensured and local destruction proceeds in stages. Is different.

  From the above, it is extremely useful as a sliding member combined sliding member of a rotary machine that handles fresh water as well as slurry containing earth and sand, non-lubricated air, and volatile liquid that generates evaporated gas due to liquid state change.

  FIG. 4 is a conceptual diagram of a sliding bearing combination sliding member according to the second embodiment of the present invention. As shown in FIG. 4, the combination in which a large number of cooling fluid passage channels 10 are provided in the vicinity of the back surface of the sliding surface 7 of the fixed bearing side sliding member 8, particularly in a high-viscosity liquid, a large amount of foreign matter, solid particles, and the like. In the state where the sliding heat generation is excessive as in the contained slurry fluid, it is excellent in securing a flow rate for removing the sliding heat and detouring and discharging foreign particles and solid particles approaching the vicinity of the sliding surface.

  To remove the sliding heat when the sliding bearing slides in the fluid, the cooling flow rate determined by the cross-sectional area of the cooling fluid passage 10 provided near the back surface of the sliding surface 7 of the fixed bearing side sliding member 8 is determined. Is a very important factor.

  In the present invention, since a metal material having excellent thermal conductivity is used for the fixed bearing side sliding member 8, the cooling fluid passage channel 10 provided in the main body of the fixed bearing side sliding member 8 is provided with the temperature of the entire sliding bearing. It is extremely effective in suppressing the rise. Further, since the cooling fluid passage hole 10 having a large cross-sectional area is provided in the vicinity of the sliding gap, solid particles are contained in the narrow sliding gap between the fixed bearing side sliding surface 7 and the rotary shaft sleeve side sliding surface 13 itself. In addition, there is a feature that the sliding surface 7 is not easily penetrated, and further, since the fixed bearing side sliding surface 7 is formed from a completely continuous surface, the fluid film generated on the sliding surface 7 is not easily damaged.

  In other words, a large detour path for foreign matter, solid particles, etc. is secured, foreign matter that causes wear and solid particles are prevented from entering the sliding surface, and fluid film formed on the sliding surface is prevented from being lost. At the same time, it has a very excellent feature in that it is compatible with the rapid removal of the generated sliding heat.

  In addition, as shown in FIG. 4, the cooling fluid passage 10 is formed by arranging a plurality of drill holes at equal intervals in the vicinity of the back surface of the sliding surface 7 of the fixed bearing side sliding member 8 manufactured integrally. Can be configured.

  Further, as shown in FIG. 7, the fixed bearing side sliding member includes a ring-shaped sliding ring 16 having a sliding surface 7 on the inner diameter side, and a fixed bearing holder 17 for fittingly holding the sliding ring 16. This can also be realized by arranging the spline-shaped cooling fluid passage channel 10 on the inner diameter side of the fixed bearing holder 17.

  Of course, as shown in FIG. 8, the fixed bearing side sliding member includes a ring-shaped sliding ring 18 having a sliding surface 7 on the inner diameter side, and a fixed bearing holder 19 for fitting and holding the sliding ring 18. This is also possible by arranging a spline-shaped cooling fluid passage channel 10 on the outer diameter side of the ring-shaped sliding ring 18.

  FIG. 5 is a development view of the sliding bearing combination sliding member according to the third embodiment of the present invention. The combination in which the ceramic sprayed coating 11 is selected on the sliding surface 7 of the fixed bearing side sliding member 8 as shown in FIG. 5 ensures wear resistance under sliding conditions under a high concentration slurry, and is also non-lubricated. In the hugging state due to the loss of the bearing gap due to sliding, it is possible to give the expansion amount due to heat generation of the inner diameter of the bearing on the fixed bearing side by the large linear expansion coefficient of the base metal 8 to be sprayed, and the volume ratio is 50% or more. The hug is delayed by securing the rotating shaft sleeve side sliding member 9 made of graphite material to be larger than the expansion amount of the outer diameter, and in particular, to increase the hugging time in continuous non-lubricated sliding. Are better.

  Further, in order to increase the hardness of the sliding surface 7 of the fixed bearing side sliding member 8 by the thermal sprayed coating 11, the sliding surface 7 is slid by thermal spraying compared to the case of using a cemented carbide or ceramics which is a simple material. The process of obtaining dynamic surface hardness greatly contributes to cost reduction.

  In surface coating treatment such as thermal spraying, vapor deposition, and plating, peeling from the end face portion perpendicular to the sliding direction of the coating proceeds, but in a sliding bearing that is made of a metal material and does not have a cooling fluid passage groove on the sliding surface. The thermal spraying part that becomes the sliding surface does not have an end face part that is perpendicular to the sliding direction, and has a great feature that it is difficult for the treated surface coating to peel off in the course of use.

  FIG. 6 is a conceptual diagram of a sliding bearing combination sliding member according to the fifth embodiment of the present invention. FIG. 6 shows the rotating shaft sleeve-side sliding member 9 exposed on the sliding surface 13 of the rotating shaft sleeve-side sliding member 9 made of carbon fiber laminated carbon-based composite material having graphite with a volume ratio of 50% or more. The metal (for example, titanium (Ti)) is vapor-deposited on the carbon (C) of the carbon fiber end face 14 to produce a high-hardness metal carbide 15a (TiC) on the carbon fiber end face 14 or a sliding member For example, silicon carbide (SiC) is generated in the carbon fiber gap 15b of the steel 9 by salt bath impregnation treatment with silicon (Si), and the wear resistance of the rotary shaft sleeve side sliding member 9 is remarkably increased by increasing the hardness of the sliding surface 13. It has the feature of improving.

  Here, the usefulness when the sliding bearing combined sliding member of the present invention disclosed in FIGS. 3 to 8 is applied to the vertical spiral pump of FIG. 9 and the vertical mixed flow pump of FIG. 10 will be described. To do.

  First, in the vertical spiral pump shown in FIG. 9, the sliding bearing combined sliding member of the present invention is used as a load-lubricated sliding bearing 23 that supports the impeller shaft 21 inside the pump casing 22. Originally, the pressure at the sliding bearing installation site is reduced during operation of this centrifugal pump, but this type of centrifugal pump requires a high discharge pressure like the process pump for transporting refined oil and the cargo handling pump pump for tankers. If the liquid to be handled is a low-vapor pressure volatile liquid such as gasoline, naphtha, acetone or methanol that vaporizes, the vicinity of the rotary shaft near the inlet of the pump impeller is intermittently vaporized. Therefore, the sliding bearing is required to have a very high non-lubricating sliding characteristic, but this problem can be solved by the present invention.

  That is, by applying the non-lubricated sliding bearing combined sliding member according to the present invention to a sliding bearing of a rotary machine such as the above pump, excellent non-lubricating sliding characteristics, thermal shock resistance, and wear resistance can be secured. It is possible to give great reliability to a rotating machine that is used while having a risk of non-lubricated sliding in an operating environment.

  As the sliding bearing combined sliding member of the present invention used for other applications, as shown in FIG. 10, it is used for a vertical mixed flow pump handling soil slurry and the like. In this mixed flow pump, the non-lubricated sliding characteristics, thermal shock resistance, and wear resistance are excellent in the intermediate bearing installation portion 25 of the impeller shaft 24 that is exposed to the air-free operation before the water level in the pump rises. When the sliding bearing combination sliding member of the present invention having the above characteristics is mounted as an intermediate bearing, a water injection device for lubrication becomes unnecessary, and the impeller holding portion 26 exposed to long-term sediment wear is also provided with the sliding of the present invention. By mounting the bearing combination sliding member as the lower bearing, it is possible to sufficiently ensure the wear resistance of the lower bearing used under the soil slurry lubrication condition.

  Ensuring long-time non-lubricated sliding characteristics is a great way to increase the allowable time for preceding standby in pumps that require the above-described prior standby idle operation, and to prevent loss of sliding bearing function during advance standby idle operation. An effect can be given.

  An example of a pump that requires such a prior standby idle operation is a drainage pump for urban disaster prevention. This pump quickly drains rainwater tanks installed underground to prevent urban flooding, so even if the water level in the rainwater tank is extremely low, the pump is operated in the standby standby mode. The sliding bearings used in the above are required to have extremely high non-lubricating sliding characteristics and thermal shock resistance capable of withstanding the thermal shock acting on the sliding bearings that have been heated to a high temperature due to a sudden rise in the water level in the rainwater tank.

  Furthermore, the very high reliability required for a pump used in public facilities can be ensured by the feature that the sliding member for sliding bearing according to the present invention does not rapidly break.

  Other applications include pumps, motors used in parts that are used at extremely low temperatures and where it is difficult to supply lubricating media, electric motors, sliding bearings for screws, or in atmospheres that have a reduced pressure environment, electric motors, It has applicability as a sliding bearing for screws.

  Here, a sliding experimental apparatus and test contents of a sliding bearing sliding member performed to clarify the practicality of the bearing combination sliding member of the present invention will be described.

  FIG. 11 shows a sliding test apparatus for a sliding bearing sliding member in the bearing combination sliding member of the present invention. Tests conducted using this experimental device were performed under various operating conditions in which a variety of existing combination sliding members were used, and repeated rapid inflow of lubricating liquid from fresh water atmosphere, slurry atmosphere, non-lubricated atmosphere and non-lubricated area. The characteristics and failure modes were investigated. As a result, it has been found that the sliding bearing combined sliding member of the present invention is very excellent.

  That is, in the vertical type sliding bearing test apparatus, the rotating shaft 29 is rotated by the upper electric motor 27 via the torque detector 28. The rotary shaft 29 is rotatably held by an upper bearing 30 and a lower test bearing 31. A test rotating shaft sleeve 32 detachably fixed to the rotating shaft 29 is inserted into the sliding portion of the lower test bearing 31 so as to be able to slide and rotate.

  An eccentric load generating disc 33 is mounted at an intermediate position between the upper bearing 30 and the lower test bearing 31, and an eccentric weight 34 for generating a swinging load is provided on the disc 33 in the radial direction. It is fixed so that it can move freely. The disc 33 to which the eccentric weight 34 is attached is rotated together with the rotary shaft 29 so as to apply a bearing load that swings around to the lower test bearing 31.

  Further, the lower test bearing 31 is detachably fixed in a test bearing installation box 35 that can be moved back and forth and left and right, and a restraining hydraulic line 36 that pressurizes the test bearing installation box 35 from one direction. Thus, a radial load is applied to the lower test bearing 31. In addition, a left load cell 37 and a right load cell 38 are installed at both ends of the test bearing installation box 35 to measure the swinging radial load, and the bearing load is measured.

  Furthermore, in order to grasp the sliding state of the lower test bearing 31, in addition to the measured load by the left and right load cells 37, 38 and the load torque by the torque detector 28, the rotating shaft 29 in the vicinity of the lower test bearing 31 is used. A displacement meter 39 for measuring the swirling displacement of the test bearing, a vibration accelerometer 40 for measuring the vibration acceleration of the test bearing installation box 35, and the inside of the lower test bearing 31 installed in the test bearing installation box 35. An upper thermometer 41 and a lower thermometer 42 for measuring the temperature of each part are installed. Further, a supply line 43 for a lubricating medium such as slurry is connected to the test bearing installation box 35.

  In the sliding test performed by the sliding shaft actual test apparatus 31, the lower test bearing performs rotational sliding at a part having an inner diameter of 100 millimeters and a sliding length of 60 millimeters, and a sliding surface pressure of 0.2 MPa × sliding. Table 1 below shows data obtained by measuring the time limit for hugging by unlubricated sliding at a dynamic speed of 6 m / sec and confirming the fracture mode at the limit.

  In addition, the sliding surface pressure is 0.075 MPa × sliding speed is 6 m / sec. Slurry is performed as a lubricant without stopping the rotation of the rotating shaft by continuously performing one cycle of non-lubricating sliding for one hour. The durability was evaluated by an intermittent non-lubricating sliding test in which a sliding test with slurry lubrication sliding for 1 hour was repeated. Table 2 below shows data obtained by measurement of the hugging limit time obtained by this test and confirmation test of the fracture mode at the limit.

The materials used are as follows.
Fixed shaft side sliding member is made of stainless steel (SUS) integrated structure, steel inner sliding surface is formed by cemented carbide (WC) spraying, cemented carbide (WC) chip is divided Arranged, manufactured with an integrated structure of silicon carbide (SiC) and silicon nitride (Si ₃ N ₄ ), zirconia (ZrO ₂ ), chromia (CrO ₂ ), A material formed by thermal spraying alumina (Al ₂ O ₃ ) or the like, and a carbon fiber yarn reinforced carbon-based composite material formed by winding a carbon fiber yarn in a pincushion shape in the rotation direction of the shaft sleeve (abbreviation in table: spool fiber) In the case of an integrated structure, a plurality of cooling fluid passages are arranged in the vicinity of the back surface of the inner sliding surface.

  As the shaft sleeve side sliding member, a carbon fiber cloth laminated carbon-based composite material (abbreviated in the table: laminated fiber) obtained by laminating carbon fiber cloth in the axial direction of the shaft sleeve, and vapor deposition on this carbon fiber cloth laminated carbon-based composite material Titanium carbide produced by treatment (abbreviation in table: + TiC), silicon carbide produced by salt bath impregnation treatment (abbreviation in table: + SiC), or empty inside carbon fiber cloth laminated carbon composite material A carbon fiber yarn reinforced carbon composite material in which the hole portion is impregnated with a metal having good affinity with carbon (abbreviation in table: + metal impregnation), and carbon fiber yarn is wound up in the rotational direction of the shaft sleeve and molded (in the table) (Abbreviation: thread wound fiber), carbon fiber cloth reinforced carbon composite material (abbreviation in table: sheet winding fiber) formed by winding a carbon fiber cloth in the rotational direction of the shaft sleeve, and cemented carbide material is 90% Including WC Nonmagnetic cemented carbide (6 mm as the shaft sleeve wall thickness, two 14 millimeters) that is containing Ni the remainder is.

  The symbols A, B, F to J and R, S in Table 1 and Table 2 are combinations of sliding bearing sliding members of the present invention, and the symbols C, D, E, and K to Q are conventional slides. It is a combination of moving members.

The symbol in the evaluation column is
◎: Reusable sufficiently at the end of test ○: Practical use in the above test △: Can be used depending on conditions in the previous test ×: Unusable in the previous test, friction coefficient, wear resistance It shows the result of comprehensive evaluation of the factors of the property and material fracture characteristics by the abnormal holding state reproduction test and the non-lubricated intermittent operation test.

  From these experiments, it has been clarified that the sliding form under the non-lubricated sliding condition can be classified according to the form of the fixed bearing side sliding surface and the rotating shaft sleeve side sliding surface. Since sliding in non-lubricating sliding repeats local contact, it can be seen that dispersion of fatigue-affected areas in sliding effectively works to stabilize sliding characteristics, but wear progresses. However, in order not to change the properties of the sliding surface, as in the present invention, as a carbon material occupying a volume ratio of 50% or more in the rotating shaft sleeve side sliding member, a mesh-like carbon fiber cloth in the rotating shaft direction is used. It is effective to laminate the material so that the end face of the carbon fiber is exposed to the sliding surface. However, in the structure in which the carbon fiber is wound up in parallel with the sliding direction, the stress acting under the non-lubricating sliding acts in the direction of loosening the fiber, so it may not be suitable for long-term non-lubricating sliding. It is clear.

  Among the various combinations of sliding surface states, select the one that is formed with a completely continuous surface that does not have a cooling fluid passage on the sliding surface of the fixed bearing side sliding member. The combination of sliding members with exposed carbon fiber end faces as sliding members allows for stable sliding operation with little change in sliding state even in a slurry atmosphere compared to other types of sliding members. In addition, the state after the inner peripheral surface of the sliding member portion of the fixed bearing side and the outer peripheral surface of the sliding member on the rotating shaft sleeve caused by the continuation of the non-lubricated sliding is also significantly damaged by the sliding material. It has the feature of not causing.

  As described above, the sliding surface of the fixed bearing side sliding member according to the present invention is selected to have a completely continuous surface that does not have a passage for cooling fluid, and a carbon fiber cloth is laminated on the rotating shaft sleeve side. The combined sliding member using carbon fiber cloth laminated carbon-based composite material exhibits extremely stable behavior under continuous thermal shock load conditions as well as wear resistance against sediment abrasion due to silica sand slurry, and after intermittent operation It was confirmed that the material state of the material was kept almost completely in the initial state, and the form of fracture was suppressed to the progress of gentle wear.

  A combination slide using a carbon fiber yarn reinforced carbon composite material formed by winding a carbon fiber yarn in the sliding direction on the fixed bearing side sliding member and using a carbon fiber cloth laminated carbon composite material on the rotating shaft sleeve side. As can be seen from the result of the symbol K in Table 1, in the moving member, the surface state on the sliding surface is not smooth on both the fixed bearing side and the rotary shaft sleeve side, and heat is generated due to an abnormal friction coefficient, and the holding is early. It was confirmed that the plain bearing lost its function at the stage.

  From the analysis of various materials destroyed by the evaluation test including non-lubricated sliding, if the failure mode of the fixed bearing and the rotating shaft sleeve in the sliding bearing is evaluated, the sliding member is different from the one in which the wear proceeds gently. The failure of the fixed bearing side sliding member is cracking and peeling of the sliding member due to slurry entering the bearing sliding gap during the slurry mixing operation, and local adhesion when holding in the non-lubricating operation. The damage to the rotating shaft sleeve side sliding member is due to the thermal stress of the metal shaft in the shaft sleeve due to the abnormal temperature rise, breakage due to tensile stress load on the rotating shaft sleeve, and the sliding direction. It was confirmed that this was due to peeling of the wound carbon fiber and loss of shape due to adhesive wear on the sliding surface due to the non-lubricating sliding state.

  The sliding bearing combined sliding member according to the present invention can maintain a very long non-lubricating sliding state even under a high load sliding condition as compared with the conventional sliding bearing combined sliding member. In addition, the material breakage due to repeated sliding in liquid and liquid is suppressed, and the wear progresses very slowly even during long-term sliding including unlubricated sliding conditions and slurry conditions. It was confirmed that the destruction of the sliding member when reaching the hugging state of the shaft sleeve side sliding outer peripheral surface does not reach the destruction of the entire sliding bearing.

  According to any of the inventions of claims 1 to 4, it has excellent non-lubricated sliding characteristics, thermal shock characteristics, and breakage delay characteristics when hugging, compared to the conventional combination sliding member. As a form realized in the best form, as shown in FIG. 5, the combination of selecting the ceramic sprayed coating 11 on the sliding surface 7 of the fixed bearing side sliding member 8 is a sliding condition under a high concentration slurry. In addition, the wear resistance is ensured in FIG. 6 and further, the amount of expansion due to heat generation of the inner diameter of the bearing on the fixed bearing side is given by the large linear expansion coefficient of the base metal 8 to be sprayed in the hugging state due to the loss of the bearing gap due to the non-lubricating sliding It is possible to delay the hugging by securing the rotating shaft sleeve side sliding member 9 made of a graphite material having a volume ratio of 50% or more to be larger than the expansion amount of the outer diameter. It is excellent in the point of increasing the embracing with time in such an unlubricated sliding.

  Further, in order to increase the hardness of the sliding surface 7 of the fixed bearing side sliding member 8 by the thermal sprayed coating 11, the sliding surface 7 is slid by thermal spraying compared to the case of using a cemented carbide or ceramics which is a simple material. The process of obtaining dynamic surface hardness greatly contributes to cost reduction.

  As a reinforcing form of the carbon fiber in the carbon fiber laminated carbon composite material used as the rotating shaft sleeve side sliding member 9, the carbon fiber end face 14 is formed on the sliding surface 13 by laminating and molding the carbon fiber material 12 in the rotating shaft direction. Is required to be dispersed and exposed over the entire sliding surface on the rotating shaft sleeve side, and further, a material in which high-hardness metal carbide 15 (TiC) is generated on the end face 14 of the carbon fiber should be selected. It is.

  In this way, even under unlubricated conditions, in liquids containing slurry such as earth and sand, and under conditions where intermittent unlubricated conditions occur, stable sliding behavior is exhibited and an immediate stop of the rotating machine is induced. It is clear that the sliding bearing combined sliding member according to the present invention improves the reliability of the sliding bearing by using a low cost material. Demonstrate great effect. Furthermore, it is possible to give a very large performance and economic advantage to the omission of the water injection device in the vertical shaft pump in which the conventional water injection device is indispensable.

  Since the present invention is configured as described above, according to any one of the first to fifth aspects of the present invention, the rubber bearing and the ceramic bearing of the conventional example can be obtained even by long-term sliding including an intermittent non-lubricated state. Compared to those using the above, it has excellent hugging resistance, seizure resistance, and thermal shock resistance, as well as sliding in water, sliding under earth and sand slurry, and intermittent exposure to air. It is very useful as a sliding bearing combined sliding member that can be used stably for a long period of time even in non-lubricated sliding or sliding in evaporating gas in a volatile liquid.

  For example, it can be used for a prior standby idle operation pump for rainwater drainage in which advance standby idle operation is intentionally forced, a chemical liquid pump internal bearing that handles gasoline and methanol volatile liquid as cargo liquid, and the like.

  If it shows an application example, as shown in FIG. 9, it can be applied as a load-lubricated sliding bearing 23 that supports the impeller shaft of the vertical spiral pump inside the pump casing. In such a centrifugal pump, the pressure at the sliding bearing installation site in the operating state is very often reduced, and in the case where the liquid handled by the pump is volatile gasoline, naphtha, acetone, methanol, etc., the bearing installation site In many cases, the lubrication fluid in the cylinder vaporizes due to changes in the state, and the normal sliding bearing sliding member combination results in intermittent aerial operation, and it is possible to solve the problem that the sliding bearings are frequently damaged. Become.

  As other applications, as shown in FIG. 10, the middle of the impeller shaft, which is a part where the sliding bearing is exposed to the air-free lubrication operation until the water level in the vertical mixed flow pump that handles sediment slurry etc. rises. The bearing part 25 or the bearing part 26 in the impeller holding part exposed to long-term sediment wear can also be used in a structure that does not require a special water injection device.

  By applying the non-lubricated sliding bearing combined sliding member according to the present invention to a sliding bearing of a rotary machine such as a pump, it is usually possible to ensure excellent non-lubricated sliding characteristics, thermal shock characteristics, and wear resistance characteristics. In the operating environment, it is possible to give great reliability to a rotating machine that is used while having a risk of non-lubricated sliding.

  Ensuring long-term non-lubricating sliding characteristics is intended to increase the allowable time for preceding standby in pumps that require the above-described prior standby idle operation, and to prevent loss of function of the sliding bearing during prior standby idle operation. It becomes possible to give a big effect.

  As a use of such a pump that requires advance standby idle operation, in order to quickly drain the rainwater tank installed underground to prevent urban flooding, even when the water level in the rainwater tank is extremely low Since the pump is operated in the standby standby idle mode, the sliding bearing used in the pump has an extremely high non-lubricating sliding performance and acts on a sliding bearing combined sliding member that has become hot due to a sudden rise in the water level in the rainwater tank. Therefore, it is necessary to have a thermal shock resistance capable of withstanding the thermal shock.

  Furthermore, the very high reliability required for a pump used in a public facility can be ensured by the feature that the sliding bearing combined sliding member according to the present invention does not proceed suddenly.

  Further, in a normal centrifugal pump, a pump that requires a particularly high discharge pressure and has a large rotation speed of the impeller of the pump is exposed to a negative pressure condition in the vicinity of the slide bearing installation position, so that the lubricating liquid is vaporized. In pumps that handle volatile liquids with low vapor pressure, it is clear that the vicinity of the rotary shaft near the inlet of the impeller is intermittently vaporized. Sliding characteristics are required.

  Examples of pumps having such a high discharge pressure and handling volatile liquids include process pumps for transporting refined oil in oil refineries and tanker cargo handling pumps for transporting refined oil obtained by petroleum refining.

  Furthermore, even as an intermediate bearing for a drive shaft of a pump having a very long vertical impeller drive shaft, even in a non-lubricated sliding state where the intermediate bearing portion is exposed before the pump water level rises due to pump activation. It becomes possible to give a big advantage to the reliability improvement in a sliding bearing part.

  Other applications include pumps, electric motors, slide bearings for screws, motors, and screws that are used at locations where it is difficult to supply lubricating media at extremely low temperatures, or pumps, electric motors used in atmospheres under reduced pressure. It has applicability as a sliding bearing for screws.

  The sliding bearing combined sliding member according to the present invention can prevent sliding heat generation due to a low friction coefficient on the premise that there is no fluid in the lubrication mechanism, and can stably secure a bearing gap for a long period of time. It is what. When the sliding bearing combined sliding member according to the present invention is applied to an industrial machine, there is no need to rely on cooling with a lubricating liquid to ensure a large cooling capacity as a cooling means in a sliding portion like a conventional fluid bearing. By applying forced air cooling or using other simple cooling methods such as a mechanism that promotes heat dissipation in sliding bearings, a method to take away heat generation at the sliding part is ensured. A dynamic sliding bearing can be realized. It is possible to omit equipment for fluid lubrication in sliding bearings applied to many industrial machines, and has great potential for rotating machinery in general.

DESCRIPTION OF SYMBOLS 1 Rotating shaft 2 Rotating shaft sleeve side sliding member 3 Fixed shaft side sliding member provided with cooling fluid passage groove 4 Cooling fluid passage groove 5 Fixed shaft side split type sliding member 6 Arrangement gap of split type sliding member 7 Sliding surface on fixed shaft side sliding member 8 Fixed shaft side sliding member 9 Rotating shaft sleeve side sliding member 10 Cooling fluid passage 11 High hardness coating 12 on fixed shaft side sliding member sliding surface Mesh carbon Ring-shaped mesh-like carbon fiber material 13 of fiber-reinforced laminated composite material Outer peripheral sliding surface 14 of mesh-like carbon fiber-reinforced laminated composite material Carbon fiber end face 15 of mesh-like carbon fiber-reinforced laminated composite material Carbon material 15a Carbon fiber surface 15b Carbon fiber gap 16 Sliding ring 17 Fixed bearing holder 18 having cooling fluid passage channel Sliding ring 19 having cooling fluid passage channel Fixed bearing holder 21 Impeller shaft 22 Pump casing 3 Fluid-lubricated sliding bearing 24 Impeller shaft 25 Intermediate bearing installation part 26 Impeller holding part 27 Electric motor 28 Torque detector 29 Rotating shaft 30 Upper bearing 31 Test fixed bearing 32 Test rotating shaft sleeve 33 Disk for generating eccentric load 34 Eccentric Weight 35 Test Bearing Installation Box 36 Restraining Hydraulic Pressure 37 Left Load Cell 38 Right Load Cell 39 Displacement Meter 40 Vibration Accelerometer 41 Upper Thermometer 42 Lower Thermometer 43 Lubricating Medium Supply Line

Claims (4)

  A combination sliding member in a sliding bearing used in a liquid containing solid particles and bubbles, in a gas-liquid mixed fluid, or in an air in which no liquid exists, and the fixed shaft side sliding member is made of a metal having a large thermal expansion coefficient. A cooling fluid passage including solid particles and bubbles is provided at a location other than the sliding surface, and the cooling fluid passage groove is not provided at all on the sliding surface of the fixed shaft side sliding member. The rotary shaft sleeve side sliding member, which is formed of a completely continuous surface and is slidably fitted to the fixed shaft side sliding member, has a smaller thermal expansion coefficient than metal, and has a volume ratio of 50% or more. A sliding bearing combined sliding member characterized by comprising a carbon material occupying the same.   The sliding bearing combined sliding member according to claim 1, wherein the passage of the gas-liquid mixed cooling fluid containing solid particles for cooling the bearing is provided on the sliding surface of the sliding bearing fixed shaft side sliding member. A sliding bearing combined sliding member characterized by being provided by being intermittently disposed in the vicinity of the back surface.   The sliding bearing combined sliding member according to claim 1 and claim 2, wherein a material having high hardness is plated, sprayed, physically, and the like on a sliding surface of a metal material constituting the sliding bearing fixed shaft side sliding member. A sliding bearing combined sliding member characterized by forming a high-hardness film by chemical vapor deposition, diffusion treatment including nitriding and carburizing, etc., and increasing the sliding surface hardness.   4. The sliding bearing combined sliding member according to claim 1, wherein the rotating shaft sleeve side sliding member is a carbon material occupying a volume ratio of 50% or more, and a mesh-like carbon fiber cloth material in the rotating shaft direction. The carbon fiber end face is exposed on the sliding surface and the carbon fiber laminated carbon composite material is endured with carbonized carbide by vapor deposition or salt bath impregnation to increase the hardness. A sliding bearing combined sliding member characterized by the above.

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