JP6488207B2 - Slide bearing device - Google Patents

Description

  The present invention relates to a sliding bearing device that is preferably used as a bearing of a rotary fluid machine such as a pump or a compressor. For example, a pump that performs operation management under dry conditions such as a preceding standby operation pump, and the like, The present invention relates to a sliding bearing device corresponding to high speed.

An example of the background art will be described based on the situation of the preceding standby operation pump in recent years.
In recent years, due to 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. The water tank 100 of the drainage station is provided with an impeller 22 at the tip of the rotary shaft 10 arranged in the vertical direction, and the water level of the water tank 100 is lower than the minimum operating water level LWL by causing the impeller 22 to suck air together with water. Also, a vertical shaft pump 3 capable of continuing the operation (preceding standby operation) is arranged. 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 slide bearing 1 made of a hollow cylindrical resin material, ceramics, sintered metal, or surface-modified metal 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 plain bearing 1 has a hollow cylindrical shape, the inner peripheral surface 1 a faces the outer peripheral surface of the sleeve 11, and the outer peripheral surface 1 b is fitted in 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 conditions without liquid lubrication. Here, the dry condition refers to a condition in which the atmosphere of the bearings 32 and 33 during 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 bearings 32 and 33 are arranged at two locations on the rotary shaft 10. However, if the length of the rotary shaft 10 is increased, more bearings are arranged accordingly. .

By the way, in recent years, the capacity of the pump has been further increased, and accordingly, the shaft diameter has been increased. Therefore, the speed of the sliding surface of the bearing has been increased.
In addition, the pumping station has been placed deeper underground, and the preceding standby pump corresponding to the pump station has been required to have a longer shaft and a higher head. In order to cope with higher heads, it is necessary to increase the number of revolutions, and it has become necessary to increase the shaft diameter and increase the rigidity in accordance with the increase in the length of the shaft.
However, increasing the shaft diameter and increasing the rotational speed may cause new technical problems. 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 rotating shaft rotates at a higher speed than in the prior art. Therefore, when the sliding bearing 1 in the bearings 32 and 33 and the sleeve 11 attached to the rotating shaft 10 slide, a great amount of frictional heat is generated at the contact portion. Is likely to occur, and there is a risk of locally high temperatures. 6 (a) and 6 (b), the hatched portion is a portion where the temperature is locally high.

Such a local high temperature of the sleeve attached to the rotary shaft may cause a high temperature and expansion of the bearing 1, but the rotary shaft 10 of the pump has a thick shaft diameter or a long shaft. Rather, as shown in FIG. 6 (a), there is a risk that the rotating shaft may bend slightly due to local expansion of the rotating shaft 10, thereby causing vibrations due to interference between the rotating portion and the fixed portion of the pump, and bearing load. Increase is likely to occur. That is, it contacts in the unbalance direction as a rotating body, and since this contact part generates heat, a temperature distribution is generated in the shaft cross section, and the shaft is bent due to thermal expansion. At this time, since the center of gravity of the rotating body is shifted due to bending, the unbalance of the entire rotating body gradually increases. Also, the bearing contact method may change due to the bending, and the temperature gradient of each bearing may change.
Further, when the displacement due to the shaft bending becomes larger than the bearing clearance, as shown in FIG. 6B, a two-point contact state with opposite phases is obtained, and the bending displacement is restrained. In addition, the pressing load increases due to continued thermal expansion, but the bearing temperature rises at an accelerated rate due to a vicious cycle of load increase ⇒ heat generation increase ⇒ thermal bending acceleration ⇒ load increase.

  Therefore, there is a demand for an apparatus or a structure having a function of reducing the bending of the rotating shaft or cooling the contact portion where the rotating shaft is heated. These are not large-scale and complicated devices, but simple devices that overcome various effects such as influence on pump efficiency and assembly / separation / adjustment of the cooling equipment and the pump are required.

  The above is an example of prior standby, but the capacity and speed of the horizontal axis multistage pump, compressor, steam turbine, etc. are also increasing, and the rotating parts such as the labyrinth seal part of these devices are fixed. In the portion where the interval between the portions is narrow, there is a concern about the bending of the rotating shaft due to local high temperature of the rotating shaft as described above, and the occurrence of vibration (rubbing vibration) associated therewith.

  Therefore, in view of such problems, the present inventors previously used a support for a rotating shaft of a rotary fluid machine in a patent application (unpublished) of Japanese Patent Application No. 2014-129688 (filed on June 24, 2014). A sliding bearing device used under dry conditions in which the bearing sliding surface is exposed to the atmosphere, comprising: a sleeve fixed to the outer periphery of the rotating shaft; and a sliding bearing having a bearing sliding surface in sliding contact with the sleeve. The sleeve is used to support the rotating shaft of a rotating fluid machine and a sliding bearing device having a three-layer structure in which a heat insulating layer, a heat transfer layer, and a sliding layer are laminated in this order from the rotating shaft side. A slide bearing device used in dry conditions exposed to the atmosphere, comprising a sleeve fixed to the outer periphery of the rotating shaft and a slide bearing having a bearing sliding surface with which the sleeve is in sliding contact. There is a sliding layer and the heat transfer layer surrounding the shaft annularly proposed a sliding bearing device to one another at the end of the sliding layer and the heat transfer layer is in contact.

  In these structures, when the sliding frictional heat generated on the surface of the sliding layer of the rotating shaft is transmitted to the heat transfer layer made of a material with good heat transfer, the sliding friction heat is quickly diffused in the circumferential direction and the axial direction by the heat transfer layer. At the same time, by providing a heat insulating layer with a material having good heat insulating properties in the radial direction, the movement of sliding frictional heat on the rotating shaft can be delayed. The purpose of this is to reduce the bending of the shaft due to thermal expansion by relaxing the temperature and making it difficult for the temperature difference in the circumferential direction to be applied. In addition, since the end portions of the sliding layer and the heat transfer layer are in contact with each other, the heat of the contact portion can be dissipated and dissipated in the heat transfer layer, and the heat can be diffused quickly. The purpose is to alleviate the temperature rise of the heat generating part of the moving material.

However, in these structures, the shortest distance to transfer heat from the place where the sliding layer is locally heated to the heat transfer layer is the thickness of the sliding layer, and since the thermal conductivity of the sliding layer is small, the sliding friction When the heat generation due to is intense, or when the thickness of the sliding layer is necessary, the temperature of the sliding layer is locally increased.
As a result, the sliding layer and the sliding bearing may be damaged. Therefore, it is necessary to reduce the local temperature increase due to sliding friction of the sliding layer, so the location of the local high temperature of the sliding layer is not known in advance where to occur, so that it can cope with where high temperature of the sliding layer Must be.

JP 2000-352396 A JP 2005-36692 A JP-A-8-248483

  The present invention has been made in view of the above problems, and in a rotating fluid machine, even if the shaft diameter of the rotating shaft increases or the shaft becomes longer, even if the peripheral speed of the outer periphery of the shaft increases, slipping occurs. An object of the present invention is to provide a plain bearing device having a function of reducing the local high temperature caused by frictional heat at a contact portion between a bearing and a shaft, and quickly dissipating and radiating heat from the contact portion.

  In order to achieve the above object, a sliding bearing device of the present invention is a sliding bearing device that is used for supporting a rotating shaft of a rotary fluid machine and is used under dry conditions in which a bearing sliding surface is exposed to the atmosphere. A sleeve fixed to the outer periphery of the rotating shaft; and a slide bearing having a bearing sliding surface with which the sleeve is slidably contacted, and the sleeve is in the order of a heat insulating layer, a heat transfer layer, and a sliding layer from the rotating shaft side. It consists of a laminated three-layer structure, the sliding layer is divided in the axial direction, an annular heat transfer ring is arranged between the divided sliding layers, and the inner peripheral surface of the heat transfer ring is the heat transfer layer It is characterized by touching.

According to a preferred aspect of the present invention, the heat transfer ring has a shorter axial length than the sliding layer.
According to a preferred aspect of the present invention, the axial lengths of the plurality of sliding layers divided into a plurality are equal.
According to a preferred aspect of the present invention, an end face in the axial direction of the heat transfer ring is in contact with an end face in the axial direction of the divided sliding layer.
According to a preferred aspect of the present invention, the outer diameter of the heat transfer ring is substantially equal to the outer diameter of the sliding layer.

According to a preferred aspect of the present invention, the heat transfer layer has a portion extending in the axial direction from one end or both ends of the sliding layer.
According to a preferred aspect of the present invention, the heat insulating layer has a gap between the rotating shaft and the heat transfer layer.
According to a preferred aspect of the present invention, the heat insulating layer has a gap between the rotating shaft and the heat insulating layer.

The rotary fluid machine of the present invention is characterized by using the above-described slide bearing device.
The pump of the present invention is characterized by using the above-mentioned plain bearing device.
A sleeve for a rotating fluid machine according to the present invention is a sleeve mounted on a rotating shaft of a rotating fluid machine, and the sleeve is a three-layer structure in which a heat insulating layer, a heat transfer layer, and a sliding layer are laminated in this order from the rotating shaft side. It has a structure, the sliding layer is divided in the axial direction, an annular heat transfer ring is arranged between the divided sliding layers, and the inner peripheral surface of the heat transfer ring is in contact with the heat transfer layer It is characterized by that.

The present invention has the following effects.
(1) In a structure in which a sleeve having a three-layer structure in which an insulating layer, a heat transfer layer, and a sliding layer are laminated in order from the inner periphery to the outer periphery is provided on the outer periphery of the rotating shaft, the sliding layer is divided in the axial direction and transmitted. Since a heat transfer ring in contact with the heat layer is provided, no matter where on the surface of the sliding layer a local high temperature is generated due to frictional heat at the contact portion between the slide bearing and the shaft, the heat transfer is transferred from the sliding layer to the heat transfer layer. In addition to heating, heat is transferred to the heat transfer layer through the heat transfer ring closest to the heat generating portion, so that heat can be quickly diffused.
(2) In a rotating fluid machine, even if the shaft diameter of the rotating shaft is increased or the shaft length is increased, and the peripheral speed of the shaft outer periphery is further increased, the local portion caused by the frictional heat of the contact portion between the slide bearing and the shaft It is possible to reduce the temperature rise and to dissipate and dissipate the heat of the contact portion quickly.

FIG. 1 is a partial schematic diagram of a vertical shaft pump that performs a prior standby operation. FIG. 2 is a diagram for explaining the operating state of the preceding standby operation. FIG. 3 is a cross-sectional view showing the entire vertical shaft pump that performs the preceding standby operation shown in FIG. 1. FIG. 4 is an enlarged view of a conventional bearing device applied to the bearing shown in FIG. FIG. 5 is a perspective view of a plain bearing installed in the bearing device shown in FIG. 6A and 6B are schematic cross-sectional views showing the state of the rotating shaft, the sleeve, and the plain bearing during the pump operation. FIG. 7 is a cross-sectional view showing a basic configuration of a bearing device according to the background art. FIG. 8A is an enlarged schematic view of the three-layered sleeve shown in FIG. 7, and FIG. 8B is an enlarged schematic view of the three-layered sleeve according to the present invention. FIG. 9 is a cross-sectional view showing the basic configuration of the bearing device according to the present invention provided with the heat transfer ring shown in FIG. 10 is a longitudinal sectional view showing a modification of the bearing device according to the present invention shown in FIG.

  In order to facilitate understanding of the plain bearing device according to the present invention, the plain bearing device proposed in Japanese Patent Application No. 2014-129688 described in the background art will be described with reference to FIGS. 7 and 8A. Subsequently, an embodiment of the plain bearing device according to the present invention will be described with reference to FIGS. 7 to 10, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

FIG. 7 is a cross-sectional view showing a basic configuration of a bearing device according to the background art. The said bearing apparatus is applied to the bearings 32 and 33 shown, for example in FIG. As shown in FIG. 7, the bearing device has a sleeve 11 having a concentric three-layer structure in which each layer has different properties on the outer periphery of the rotating shaft 10. The sleeve 11 is fixed to the rotating shaft 10 and rotates with the rotation of the rotating shaft 10. A plain bearing 1 is disposed so as to surround the sleeve 11 so as to face the outer periphery of the sleeve 11. The plain bearing 1 is fixed to a support member 13 connected to a pump casing or the like via a bearing case 12.
As shown in FIG. 7, the sleeve 11 is laminated on the heat insulating layer 11 </ b> A, the heat transfer layer 11 </ b> B, and the sliding layer 11 </ b> C from the rotating shaft side, and the outer periphery of the sliding layer 11 </ b> C is opposed to the inner periphery of the slide bearing 1. ing. The heat insulating layer 11A includes a case where the heat insulating property of the material itself is used and a case where the material itself does not have a heat insulating property but has a heat insulating property structurally.

  The heat insulating layer 11A is made of a resin such as PTFE (polytetrafluoroethylene), PA (polyamide), PC (polycarbonate), EP (epoxy resin), PEEK (polyetheretherketone) and the like, and / or NBR (nitrile). Rubber), FKM (fluoro rubber), EPDM and the like. The heat transfer layer 11B is made of a metal having a high thermal conductivity such as copper, gold, silver, or aluminum and an alloy thereof, or carbon and a composite material thereof. The sliding layer 11C is made of resin and its composite material, stainless steel, ceramics, sintered metal, surface-modified metal, carbon and its composite material.

The characteristic of each layer is that the heat transfer layer 11B has better heat transfer than any of the rotating shaft 10, the sliding layer 11C, and the heat insulating layer 11A. That is, the heat transfer coefficient is large. The heat transfer layer 11B is in close contact with the outer sliding layer 11C so as to increase the contact area. Because of this structure, the heat transfer layer 11B can easily transfer heat to the entire heat transfer layer through the heat transfer layer 11B even if frictional heat is locally generated at any place on the sliding layer 11C and the temperature becomes high. Heat diffuses and the temperature of the entire heat transfer layer rises evenly.
The heat insulating layer 11A has poor heat transfer compared to the rotating shaft 10 and the sliding layer 11C. That is, the heat transfer coefficient is small. For this reason, the frictional heat generated locally in the sliding layer 11 </ b> C is prevented from transferring heat to the rotating shaft 10 only through the shortest distance of the heat transfer route to the rotating shaft 10. In order to prevent heat from being easily transferred from the heat transfer layer 11B to the rotating shaft 10, the heat insulating layer 11A is interposed between the surface of the heat transfer layer 11B and the surface of the rotating shaft 10, and the heat transfer layer 11B is connected to the rotating shaft 10. To prevent close contact. In addition, as shown in the drawing, a portion extending radially outward in a flange shape is formed at the end of the heat insulating layer 11A, and direct contact between the heat transfer layer 11B and the rotating shaft 10 and between the sliding layer 11C and the rotating shaft 10 are formed. Direct contact may be prevented.

Since heat is not easily transferred from the heat transfer layer 11B to the rotating shaft 10, the heat transferred from the sliding layer 11C once accumulates in the heat transfer layer 11B, and the temperature can be increased uniformly throughout the heat transfer layer 11B.
When the temperature of the heat transfer layer 11B rises uniformly according to the frictional heat of the sliding layer 11C and the temperature difference with the rotating shaft 10 gradually increases, the heat according to the temperature difference and the heat transfer coefficient of the heat insulating layer 11A Flows to the rotating shaft 10. If the frictional heat becomes constant, the temperature difference between the heat transfer layer 11B and the rotating shaft 10 becomes constant. The smaller the heat transfer coefficient of the heat insulating layer 11A, the larger the temperature difference and the smaller the temperature rise of the rotating shaft 10.

FIG. 8A is an enlarged schematic view of the three-layered sleeve shown in FIG. In this structure, the shortest distance for transferring heat from the place where the sliding layer 11C is locally heated to the heat transfer layer 11B is the thickness of the slide layer 11C, and the heat is the heat transfer layer 11B as indicated by the white arrow. It is transmitted to. However, since the thermal conductivity of the sliding layer 11C is small, when the heat generation due to sliding friction is severe or when the thickness of the sliding layer 11C is necessary, the temperature of the sliding layer 11C increases locally.
As a result, the sliding layer 11C and the slide bearing 1 may be damaged.

  On the other hand, FIG. 8B is an enlarged schematic view of the sleeve 11 having a three-layer structure according to the present invention. In the structure of the present invention, the sleeve 11 is laminated on the heat insulating layer 11A, the heat transfer layer 11B, and the sliding layer 11C from the rotating shaft side, as in the structure shown in FIG. It is divided by the heat transfer ring 11B ′ in the direction. The heat transfer ring 11B ′ is annular, the inner diameter of the heat transfer ring 11B ′ is in contact with the outer diameter of the heat transfer layer 11B, and the outer diameter of the heat transfer ring 11B ′ is substantially equal to the outer diameter of the sliding layer 11C. Both axial surfaces of the thermal ring 11B ′ are in contact with the axial surfaces of the divided sliding layer 11C. The length in the axial direction of the heat transfer ring 11B 'is smaller than the length in the axial direction of one divided sliding layer 11C. Further, the positions of the heat transfer ring 11B ′ and each of the divided sliding layers 11C are axially symmetric with respect to the alternate long and short dash line L passing through the center of the heat transfer ring 11B ′ in the axial direction as shown in the figure. It is preferable that

In this way, in addition to the heat transfer path passing through the radial thickness of the sliding layer 11C from the place where the sliding layer 11C is locally heated, the transmission closest to the place where the sliding layer 11C is locally heated is performed. Since a heat transfer path for transferring heat to the heat ring 11B ′ is formed, heat can be quickly transferred to the heat transfer layer 11B via the heat transfer ring 11B ′ as compared to the conventional heat transfer path.
Further, when the positions of the heat transfer ring 11B ′ and each of the divided sliding layers 11C are made axially symmetric with respect to the alternate long and short dash line L, a local high temperature is generated on either side of the divided sliding layer 11C. Since the distance to the heat transfer ring 11B ′ is relatively uniform even if the temperature is changed, the heat at the contact portion can be quickly dispersed and radiated, and the heat can be prevented from being biased locally at the contact portion.

FIG. 9 is a cross-sectional view showing a basic configuration of a bearing device according to the present invention including the heat transfer ring 11B ′ shown in FIG. The bearing device is applied to the bearings 32 and 33 shown in FIG. 3, for example, as in FIG.
As shown in FIG. 9, the bearing device of the present invention has a sleeve 11 having a concentric three-layer structure on the outer periphery of the rotating shaft 10 and each layer having different properties. The sleeve 11 is fixed to the rotating shaft 10 and rotates with the rotation of the rotating shaft 10. A plain bearing 1 is disposed so as to surround the sleeve 11 so as to face the outer periphery of the sleeve 11. The plain bearing 1 is fixed to a support member 13 connected to a pump casing or the like via a bearing case 12.

  As shown in FIG. 9, the sleeve 11 is laminated on the heat insulating layer 11 </ b> A, the heat transfer layer 11 </ b> B, and the sliding layer 11 </ b> C from the rotating shaft side, and the outer periphery of the sliding layer 11 </ b> C is opposed to the inner periphery of the slide bearing 1. ing. The sliding layer 11C is divided into a plurality of portions in the axial direction by a plurality of heat transfer rings 11B '. Each heat transfer ring 11B ′ is annular, the inner diameter of the heat transfer ring 11B ′ is in contact with the outer diameter of the heat transfer layer 11B, and the outer diameter of the heat transfer ring 11B ′ is substantially equal to the outer diameter of the sliding layer 11C. Both axial surfaces of the heat transfer ring 11B ′ are in contact with the axial surfaces of the divided sliding layer 11C. The length in the axial direction of each heat transfer ring 11B 'is smaller than the length in the axial direction of one divided sliding layer 11C.

In this way, even if frictional heat is locally generated in the sliding layer 11C and the temperature becomes high, the heat transfer layer 11B and the heat transfer ring 11B ′ can easily transfer heat, so the heat transfer layer 11B and the heat transfer ring 11B ′. Through this, heat is quickly diffused throughout the heat transfer layer, and the temperature of the entire heat transfer layer rises evenly.
In addition to the heat transfer path passing through the radial thickness of the sliding layer 11C from the place where the sliding layer 11C is locally heated, the heat transfer ring 11B ′ closest to the place where the sliding layer 11C is locally heated Since a heat transfer path for transferring heat is formed, heat can be transferred to the heat transfer layer 11B more quickly through the heat transfer ring 11B ′ than the conventional heat transfer path.

The heat insulating layer 11A is made of a resin such as PTFE (polytetrafluoroethylene), PA (polyamide), PC (polycarbonate), EP (epoxy resin), PEEK (polyetheretherketone) and the like, and / or NBR (nitrile). Rubber), FKM (fluoro rubber), EPDM and the like. However, the heat insulating layer 11A includes a case where the heat insulating property of the material itself is used and a case where the material itself does not have a heat insulating property but has a heat insulating property structurally.
The heat transfer layer 11B and the heat transfer ring 11B ′ are not necessarily made of the same material, but are made of a metal having a high thermal conductivity such as copper, gold, silver, or aluminum and an alloy thereof, or carbon and a composite material thereof.
The sliding layer 11C is made of resin and its composite material, stainless steel, ceramics, sintered metal, surface-modified metal, carbon and its composite material.

The characteristic of each layer is that the heat transfer layer 11B and the heat transfer ring 11B ′ have better heat transfer than any of the rotating shaft 10, the sliding layer 11C, and the heat insulating layer 11A. That is, the heat transfer coefficient is large. The heat transfer layer 11B is in close contact with the outer sliding layer 11C so as to increase the contact area.
As shown in FIG. 9, the sliding layer 11C may be further finely divided by a plurality of heat transfer rings 11B ′. The length obtained by adding all the axial lengths of the divided sliding layer 11C and the radial thickness of the sliding layer 11C are determined according to the sliding load.

On the other hand, the axial length of the divided sliding layer 11C is better when considering only heat transfer, but shorter when considering the sliding load and assembly. By the way, even if the length of the sliding layer 11C is about 2 to 8 times the radial thickness, the heat transfer layer can generate 1.5 to 3 times as much heat as that shown in FIG. 11B or heat transfer ring 11B ′.
In addition, the length of the heat transfer ring 11B ′ in the axial direction is better when considering only heat transfer, but not always when considering the sliding load. Since the thermal conductivity of the sliding layer 11C is one digit or more smaller than the thermal conductivity of the heat transfer layer 11B or the heat transfer ring 11B ′, the length of the heat transfer ring 11B ′ is the radial direction of the sliding layer 11C. The thickness may be about 1 to ¼ times the thickness.

In addition, the length in the axial direction of each sliding layer 11C is preferably the same length, and the length in the axial direction of each heat transfer ring 11B ′ is also preferably the same length.
Further, the positions of the heat transfer ring 11B ′ and each of the divided sliding layers 11C are axially symmetric with respect to an alternate long and short dash line L passing through the center of the central heat transfer ring 11B ′ in the axial direction as shown in the figure. It is preferable to be in a state. In this way, since the distance to the heat transfer ring 11B ′ is relatively uniform no matter where the local temperature rises in the divided sliding layer 11C, the heat of the contact portion can be quickly dissipated and dissipated. It is possible to prevent the heat from being biased locally.
Incidentally, the heat transfer ring 11B ′ may be provided at one place as shown in FIG. 8B or at a plurality of places as shown in FIG.

  The heat insulating layer 11A has poor heat transfer compared to the rotating shaft 10 and the sliding layer 11C. That is, the heat transfer coefficient is small. For this reason, the frictional heat generated locally in the sliding layer 11 </ b> C is prevented from transferring heat to the rotating shaft 10 only through the shortest distance of the heat transfer route to the rotating shaft 10. In order to prevent heat from being easily transferred from the heat transfer layer 11B to the rotating shaft 10, the heat insulating layer 11A is interposed between the surface of the heat transfer layer 11B and the surface of the rotating shaft 10, and the heat transfer layer 11B is connected to the rotating shaft 10. To prevent close contact. In addition, as shown in the drawing, a portion extending radially outward in a flange shape is formed at the end of the heat insulating layer 11A, and direct contact between the heat transfer layer 11B and the rotating shaft 10 and between the sliding layer 11C and the rotating shaft 10 are formed. Direct contact may be prevented.

Since heat is not easily transferred from the heat transfer layer 11B to the rotating shaft 10, the heat transferred from the sliding layer 11C once accumulates in the heat transfer layer 11B, and the temperature can be increased uniformly throughout the heat transfer layer 11B.
When the temperature of the heat transfer layer 11B rises uniformly according to the frictional heat of the sliding layer 11C and the temperature difference with the rotating shaft 10 gradually increases, the heat according to the temperature difference and the heat transfer coefficient of the heat insulating layer 11A Flows to the rotating shaft 10. If the frictional heat becomes constant, the temperature difference between the heat transfer layer 11B and the rotating shaft 10 becomes constant. The smaller the heat transfer coefficient of the heat insulating layer 11A, the larger the temperature difference and the smaller the temperature rise of the rotating shaft 10.

10 is a longitudinal sectional view showing a modification of the bearing device according to the present invention shown in FIG.
The bearing device shown in FIG. 10 has the same basic configuration as that shown in FIG. That is, the sleeve 11 is laminated on the heat insulating layer 11A, the heat transfer layer 11B, and the sliding layer 11C from the rotating shaft side, and the outer periphery of the sliding layer 11C is opposed to the inner periphery of the slide bearing 1. However, the sliding layer 11C is divided into a plurality of portions in the axial direction by the heat transfer ring 11B ′.

The inner diameter of the heat transfer ring 11B ′ is in contact with the outer diameter of the heat transfer layer 11B, and the outer diameter of the heat transfer ring 11B ′ is substantially equal to the outer diameter of the sliding layer 11C. The heat transfer ring 11B ′ is in contact with the divided sliding layer 11C in the axial direction. The length of the heat transfer ring 11B ′ in the axial direction is smaller than the length of the divided sliding layer 11C.
As shown in FIG. 10, in addition to the configuration of FIG. 9, the heat transfer layer 11 </ b> B is a portion extending in the axial direction from both ends of the sliding layer 11 </ b> C, and the volume of the heat transfer layer 11 </ b> B is increased to increase the heat capacity. In addition, portions 11Ba and 11Ba that are in direct contact with the outside air are provided.

  By doing in this way, the temperature of the heat transfer layer 11B can be raised slowly, and it can function as a heat radiating part by being in direct contact with the outside air. As shown in FIG. 10, since the heat capacity of the heat transfer layer 11B is increased and the heat is dissipated, the frictional heat of the sliding portion 11C is easily transmitted to the heat transfer layer 11B, and from the heat transfer layer 11B to the rotating shaft. The amount of heat transfer to 10 can be relatively reduced.

In the bearing device shown in FIG. 9, the heat insulating performance of the heat insulating layer 11 </ b> B has been described in terms of the heat conductivity of the material used. However, the bearing device shown in FIG. 10 has a structurally reduced heat transfer coefficient. It is.
As shown in FIG. 10, the space 11g is provided in the heat insulating layer 11A. In the example shown in FIG. 10, the gap 11 g is provided in a belt shape in the circumferential direction of the rotating shaft 10. Since the space between the air gaps is air, heat transfer is less than that due to solids. If such an air layer is held in a well-balanced manner, the heat insulating effect is improved as compared with the case where a material having a low thermal conductivity is simply used as the heat insulating layer.
A plurality of gaps 11g may be provided in the axial direction on the inner peripheral side of the heat insulating layer 11A.

  The bearing device according to the present invention shown in FIGS. 9 and 10 is replaceable. Specifically, the sleeve 11 and / or the slide bearing 1 are divided so that the bearing device can be easily replaced.

The bearing device according to the present invention shown in FIGS. 8B to 10 is applied to the bearings 32 and 33 shown in FIG.
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 conditions without liquid lubrication. Here, the dry condition refers to a condition in which the atmosphere of the bearings 32 and 33 during 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 operation of the pump is in water mixed with foreign matter (slurry) such as earth and sand. It refers to water-mixing operation, full-volume operation, air lock operation, etc. The bearings 32 and 33 are used under such conditions.

  According to the present invention, the vertical shaft pump 3 is provided with the bearing device having the sleeve structure described so far, so that the diameter of the rotary shaft is increased or the shaft length is increased, and the peripheral speed of the outer periphery of the shaft is further increased. In addition, the bending of the shaft due to the local high temperature of the rotating shaft 10 due to the frictional heat of the contact portion between the sliding bearing 1 and the rotating shaft 10 can be reduced, and the heat of the contacting portion can be more quickly dispersed and radiated. As a result, damage to the sliding bearing 1 due to heat can be reduced.

As described above, the specific embodiment according to the present invention has been described by taking the preceding standby pump as an example.
By the way, the sleeve according to the present invention or the sleeve having a structure in which the sliding layer and the heat transfer layer surround the rotating shaft in a state where the end portions of the sliding layer and the heat transfer layer are in contact with each other is not limited to a plain bearing. For example, it can be attached to a rotating shaft of a rotating fluid machine that operates under conditions without liquid lubrication, such as a compressor or a steam turbine, and can be used for a labyrinth seal portion or the like. Moreover, it is used not only for a vertical axis but also for a horizontal axis rotary machine. By doing so, it is possible to increase the capacity of the rotating fluid machine and increase the speed of rotation by suppressing the increase in the temperature of the sleeve and the bending of the rotating shaft.

  Although the embodiment of the present invention has been described so far, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention may be implemented in various different forms within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 1 Slide bearing 1a Inner peripheral surface 1b Outer peripheral surface 3 Vertical shaft pump 5 Through-hole 6 Air pipe 6a Opening 10 Rotating shaft 11 Sleeve 11A Heat insulation layer 11B Heat transfer layer 11Ba Heat transfer layer extension part 11B 'Heat transfer ring 11C Sliding layer 11g Gap 12 Bearing case 12a Collar portion 13 Support member 22 Impeller 26 Shaft coupling 27 Suction bell 28 Discharge bowl 29 Casing 30 Discharge elbow 32 Upper bearing 33 Lower bearing 34 Shaft seal 100 Water tank

Claims (11)

A sliding bearing device used for supporting a rotating shaft of a rotating fluid machine and used in dry conditions in which a bearing sliding surface is exposed to the atmosphere,
A sleeve fixed to the outer periphery of the rotating shaft;
A slide bearing having a bearing sliding surface with which the sleeve slides,
The sleeve has a three-layer structure in which a heat insulating layer, a heat transfer layer, and a sliding layer are laminated in this order from the rotating shaft side
The sliding layer is divided in the axial direction, an annular heat transfer ring is arranged between the divided sliding layers,
A sliding bearing device, wherein an inner peripheral surface of the heat transfer ring is in contact with the heat transfer layer.   The plain bearing device according to claim 1, wherein the heat transfer ring has a shorter axial length than the sliding layer.   The sliding bearing device according to claim 1 or 2, wherein the sliding layers divided into a plurality of pieces have the same length in the axial direction.   4. The plain bearing device according to claim 1, wherein an end face in the axial direction of the heat transfer ring is in contact with an end face in the axial direction of the divided sliding layer. 5.   The sliding bearing device according to any one of claims 1 to 4, wherein an outer diameter of the heat transfer ring is substantially equal to an outer diameter of the sliding layer.   The sliding bearing device according to claim 1, wherein the heat transfer layer has a portion extending in an axial direction from one end or both ends of the sliding layer.   The sliding bearing device according to any one of claims 1 to 6, wherein the heat insulating layer has a gap between the rotating shaft and the heat transfer layer.   The sliding bearing device according to any one of claims 1 to 6, wherein the heat insulating layer has a gap between the rotating shaft and the heat insulating layer.   A rotary fluid machine using the plain bearing device according to any one of claims 1 to 8.   A pump using the plain bearing device according to any one of claims 1 to 8. A sleeve mounted on a rotating shaft of a rotating fluid machine,
The sleeve has a three-layer structure in which a heat insulating layer, a heat transfer layer, and a sliding layer are laminated in this order from the rotating shaft side,
The sliding layer is divided in the axial direction, an annular heat transfer ring is arranged between the divided sliding layers,
The sleeve for a rotating fluid machine, wherein an inner peripheral surface of the heat transfer ring is in contact with the heat transfer layer.