Vertical shaft pump
The vertical shaft pump addresses heat dissipation issues by using high thermal conductivity members and an elastic member to reduce frictional heat and prevent bearing damage, ensuring reliable operation during idling.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- HITACHI IND PROD LTD
- Filing Date
- 2022-11-22
- Publication Date
- 2026-07-16
AI Technical Summary
Existing vertical shaft pumps face challenges in heat dissipation at the bearing sliding member, particularly at the axial ends, leading to potential bearing damage due to uneven contact and excessive temperature rise during idling operations without lubrication.
The vertical shaft pump incorporates high thermal conductivity members on the outer circumference and axial ends of the bearing sliding member, along with an elastic member, to dissipate frictional heat effectively, reducing uneven contact and temperature rise.
The solution enhances heat dissipation, minimizing frictional heat generation and preventing bearing damage, ensuring a reliable operation even during idling without lubrication.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a vertical pump provided with a bearing device for supporting a rotating shaft, and particularly to a vertical pump provided with a bearing device in which non-lubricated sliding and sliding in pumped water containing foreign substances and the like are repeated.
Background Art
[0002] In recent years, during heavy rain concentrated in urban areas, the inflow of rainwater into drainage pump stations (hereinafter, also simply referred to as drainage stations) has been large and rapid, and the risk of urban flooding has been increasing. In order to avoid the occurrence of such urban flooding, a drainage pump that operates promptly even in an emergency is required. Therefore, during normal times when no flood has occurred, idling operation of drainage pumps such as vertical pumps installed in drainage stations is carried out to check their operation.
[0003] In addition, in order to prevent waterlogging damage due to a delay in starting the drainage pump against a rapid and large inflow of rainwater into the drainage pump station, a pre-waiting operation is strongly required in which the drainage pump is idled and put into a standby operation before the rainwater flows into the drainage station so that drainage can be immediately performed when water is discharged.
[0004] In a pre-waiting operation type vertical pump that performs this pre-waiting operation, since the idling operation time during which pumping is not performed becomes long, in a bearing device of the pump that uses pumped water of the pump as a lubricating fluid, non-lubricated sliding without lubricating fluid in the bearing device continues for a long time. As a result, there is a high risk of problems such as damage to the bearing device due to heat generation caused by frictional sliding.
[0005] To resolve such problems, the bearing device for a vertical shaft pump described in Japanese Patent Publication No. 2009-203933 (Patent Document 1) uses a composite resin bearing sliding member that is positioned opposite the outer circumferential surface of the rotating shaft of the vertical shaft pump, and has a configuration in which a plurality of pins made of a material with a higher thermal conductivity than the bearing sliding member are provided on the side opposite the sliding surface of the bearing sliding member. With this configuration, in Patent Document 1, the heat generated by the sliding between the resin bearing sliding member with low thermal conductivity and the rotating shaft does not remain inside the bearing sliding member, but is dissipated to the outside of the bearing sliding member via the pins with high thermal conductivity. [Prior art documents] [Patent Documents]
[0006] [Patent Document 1] Japanese Patent Publication No. 2009-203933 [Overview of the project] [Problems that the invention aims to solve]
[0007] In the above-mentioned Patent Document 1, while the heat dissipation effect can be enhanced in the part of the bearing sliding member where the pin is installed, heat dissipation becomes difficult in the part of the bearing sliding member where the pin is not installed, leading to a rise in the temperature of the bearing sliding member and an increased risk of bearing damage. Furthermore, it has been found that when the rotating shaft and the bearing sliding member of the bearing device come into contact, uneven contact is likely to occur at the axial end, and when uneven contact occurs, the contact pressure becomes very high, resulting in a particularly large amount of heat generation. However, it is difficult to install the aforementioned heat dissipation pins with high thermal conductivity at the axial end of the bearing sliding member, and the heat dissipation effect cannot be enhanced, so there is a problem that excessive temperature rise occurs, especially at the end of the bearing sliding member, which can cause bearing damage.
[0008] The object of the present invention is to provide a vertical shaft pump that can improve the heat dissipation of frictional heat generated at the sliding portion between the rotating shaft and the bearing device, thereby suppressing bearing damage. [Means for solving the problem]
[0009] To achieve the above objective, the present invention provides a vertical shaft pump comprising a rotating shaft extending vertically, an impeller fixed to the lower end of the rotating shaft and rotating together with the rotating shaft, and a bearing device supporting the rotating shaft, wherein the bearing device uses the pumped water as a lubricant during pumping operation and can operate with unlubricated sliding without a lubricant during idling operation. Supporting the aforementioned rotating shaft A bearing sliding member is provided at the portion of the bearing device that slides in contact with the rotating shaft, and this bearing sliding member is housed in a bearing housing. A high thermal conductivity member is provided on the outer circumference of one or both axial ends of the bearing sliding member to dissipate heat towards the bearing housing, and this high thermal conductivity member is made of a material with higher thermal conductivity than the material arranged on the central outer circumference of the bearing sliding member.
[0010] Another feature of the present invention is a vertical shaft pump comprising a rotating shaft extending vertically, an impeller fixed to the lower end of the rotating shaft and rotating together with the rotating shaft, and a bearing device supporting the rotating shaft, wherein the bearing device uses the pumped water as a lubricant during pumping operation and can operate with unlubricated sliding without a lubricant during idling operation. Supporting the aforementioned rotating shaft A bearing sliding member is provided at the portion of the bearing device that slides against the rotating shaft, this bearing sliding member is housed in a bearing housing, and an elastic member is provided so as to contact the outer circumference of the axial center of the bearing sliding member and the inner circumference of the bearing housing, and a high thermal conductivity member is provided on the outer circumference of the axial end of the bearing sliding member, which is made of a material with higher thermal conductivity than the elastic member located on the central outer circumference of the bearing sliding member, in order to release the heat generated by the bearing sliding member to the bearing housing. [Effects of the Invention]
[0011] According to the present invention, it is possible to obtain a vertical shaft pump that can suppress bearing damage by improving the heat dissipation of frictional heat generated at the sliding part between the rotating shaft and the bearing device. [Brief explanation of the drawing]
[0012] [Figure 1] This is a longitudinal cross-sectional view showing Embodiment 1 of the vertical shaft pump of the present invention. [Figure 2] Figure 1 is an enlarged cross-sectional view of the main part of the bearing device section of the vertical shaft pump. [Figure 3] This figure illustrates an embodiment 2 of the vertical shaft pump of the present invention, and corresponds to Figure 2. [Modes for carrying out the invention]
[0013] Specific embodiments of the vertical shaft pump of the present invention will be described below with reference to the drawings. In each figure, parts denoted by the same reference numerals are the same or corresponding parts. [Examples]
[0014] One embodiment of the vertical shaft pump of the present invention will be described with reference to Figures 1 and 2. First, the overall configuration of the vertical shaft pump in this embodiment 1 will be explained using Figure 1. Figure 1 is a longitudinal cross-sectional view showing embodiment 1 of the vertical shaft pump of the present invention.
[0015] Figure 1 shows a vertical shaft pump, which comprises a rotating shaft 1 that extends and rotates vertically, an impeller 2 fixed to the lower end of the rotating shaft 1 and rotating together with the rotating shaft 1, a pump casing 3 that covers the outer circumference of the impeller 2, a water lifting pipe 4 connected to the upper part of the pump casing 3 and extending further upward, and a discharge elbow section 5 connected to the upper part of the water lifting pipe 4 and bending the flow path horizontally. The rotating shaft 1 is supported by bearing devices 6 and 7 and is configured to be rotationally driven by a prime mover such as a motor 10 installed on a support base 15 provided on the floor 9a of the water intake tank 9 via a coupling 8. 3a is a suction bell mouth provided on the suction port side of the pump casing 3.
[0016] The bearing device 6 is arranged near the impeller 2, rotatably supports the lower end side of the rotating shaft 1, and is fixed to the pump casing 3 via guide vanes 11 or the like. The bearing device 7 rotatably supports the rotating shaft 1 at a portion below the floor portion 9a of the suction tank 9, which is the installation surface of the vertical shaft pump 100 (the central portion side in the vertical direction of the rotating shaft 1), and is fixed to the lift pipe 4 via a support member 12.
[0017] The vertical shaft pump 100 shown in FIG. 1 is a vertical shaft pump that performs idling operation for operation confirmation or the like, or a vertical shaft pump of a pre-waiting operation type. For the bearing devices 6 and 7, those of a type that can use the pumped water as a lubricant during the pumping operation and operate with non-lubricated sliding without a lubricant (dry operation) during the idling operation are used.
[0018] Further, as the vertical shaft pump of the pre-waiting operation type, for example, as described in Japanese Patent Laid-Open No. 6-213190, when the water level during the pump operation is below the minimum water level at which air is sucked from the suction bellmouth 3a of the pump casing 3, the impeller 2 is positioned below the corresponding water level, and a plurality of air introduction portions (not shown) are provided in the pump casing 3 below the impeller 2. It is preferable to provide an intake pipe (not shown) having one end connected to the air introduction portion and the other end open to the atmosphere for the air introduction portion.
[0019] FIG. 2 is an enlarged cross-sectional view of the main part of the bearing device 6 or 7 in the vertical shaft pump shown in FIG. 1. In the following description, the bearing device shown in FIG. 2 will be described when it is the bearing device 7 shown in FIG. 1, but the bearing device 6 has the same configuration. In FIG. 2, only the right half of the bearing device 7 is shown, but since the left half has the same configuration, the illustration of the left half is omitted.
[0020] In FIG. 2, 1 is the rotating shaft of the vertical shaft pump 100, 7 is the bearing device that rotatably supports the rotating shaft 1, and a shaft sleeve 13 is fitted and fixed to the outer peripheral surface of the rotating shaft 1 at the portion supported by this bearing device 7. When the rotating shaft 1 has a shaft sleeve 13, the shaft sleeve is also included and referred to as the rotating shaft.
[0021] The bearing device 7 is composed of a bearing sliding member 21 provided on the inner peripheral side and slidingly contacting the shaft sleeve 13, a back metal 22 provided on the back side of the bearing sliding member 21 for holding the bearing sliding member 21, a bearing housing 23 for holding the back metal 22, etc. The bearing housing 23 is fixed to the support member 12 (see also FIG. 1).
[0022] The bearing sliding member 21 is made of a material that can use the pumped water as a lubricant during the pumping operation and can operate with non-lubricated sliding without a lubricant during the idling operation without pumping. As this bearing sliding member 21, for example, a resin material of the PEEK (polyether ether ketone) type or a composite resin made by reinforcing a resin material with carbon fiber may be used. In addition to PEEK, as the resin material, PI (polyimide), PAI (polyamideimide), PBI (polybenzimidazole), PTFE (polytetrafluoroethylene), PPS (polyphenylene sulfide), etc. may also be used.
[0023] In this embodiment, flexible high heat conduction members (high heat conduction flexible materials) 26 (26a, 26b) are provided on the outer peripheral surfaces at both upper and lower end portions in the axial direction of the bearing sliding member 21 so as to contact the outer peripheral surface of the bearing sliding member 21 and the inner peripheral surface of the back metal 22. Further, in this embodiment, flexible annular high heat conduction members (high heat conduction flexible materials) 27 (27a, 27b) are provided on the end face portions at both axial ends of the bearing sliding member 21 and the back metal 22 so as to contact both the bearing sliding member 21 and the back metal 22.
[0024] The annular high-thermal-conductivity members 27 (27a, 27b) are held by bearing retainers 28 (28a, 28b) fixed to the back metal 22 or the bearing housing 23. The upper annular high-thermal-conductivity member 27a is pressed from above by the bearing retainer 28a and is in close contact with the upper end surfaces of the bearing sliding member 21 and the back metal 22. Similarly, the lower annular high-thermal-conductivity member 27b is pressed from below by the bearing retainer 28b and is in close contact with the lower end surfaces of the bearing sliding member 21 and the back metal 22. The bearing retainer 28 may be integrally formed with the back metal 22 or the bearing housing 23.
[0025] As described above, in this embodiment, flexible, highly heat-conductive members 26 are provided on the outer circumferential surfaces of both the upper and lower axial ends of the bearing sliding member 21 so as to be in contact with the outer circumferential surface of the bearing sliding member 21 and the inner circumferential surface of the back metal 22. Furthermore, annular, highly heat-conductive members 27 are provided on the end faces of both the bearing sliding member 21 and the back metal 22 so as to be in contact with both the bearing sliding member 21 and the back metal 22. The reason for this will be explained below.
[0026] Due to assembly misalignment (assembly error) in the vertical shaft pump 100 and the radial fluid force acting on the impeller 2 attached to the lower end of the rotating shaft 1, the axis of the shaft sleeve 13 and the axis of the bearing sliding member 21 are not necessarily parallel, and are in a slightly tilted positional relationship due to the inclination and deflection of the rotating shaft 1. When the positional relationship between the shaft sleeve 13 and the bearing sliding member 21 is in this state, uneven contact occurs where the axial upper or lower end of the bearing sliding member 21 and the shaft sleeve 13 come into particularly strong contact. The amount of frictional heat generated in this strongly contacting area is particularly large, and the temperature of the bearing sliding member 21 in this area rises particularly high, increasing the risk of bearing damage such as seizure.
[0027] In this embodiment, flexible, highly heat-conductive members 26 are provided on the outer circumference of both axial ends (upper and lower ends) of the bearing sliding member 21, corresponding to positions where the shaft sleeve 13 and the bearing sliding member 21 are in strong contact and the amount of frictional heat generated is particularly large. These members are in contact with the outer circumference of the bearing sliding member 21 and the inner circumference of the back metal 22. Additionally, flexible, annular, highly heat-conductive members 27 are provided on both axial ends of the bearing sliding member 21 and the back metal 22. In this embodiment, the highly heat-conductive members 26 and the annular, highly heat-conductive members 27 are made of materials with a higher thermal conductivity than the material used for the bearing sliding member 21 and a lower rigidity than the material used for the back metal 22.
[0028] In this embodiment, the high thermal conductivity member 26 for dissipating heat towards the bearing housing 23 is provided on the outer circumference of both axial ends of the bearing sliding member 21, but it may also be provided on only one of the axial ends. In this case, it is preferable to provide it on either the upper or lower end, depending on the characteristics of the machine to which it is applied. Similarly, the annular high thermal conductivity member 27 may also be provided on either the upper or lower end of the bearing sliding member 21.
[0029] In this embodiment, the high thermal conductivity member 26 is made of a material with higher thermal conductivity than the material arranged on the central outer circumference of the bearing sliding member 21. Furthermore, in this embodiment, the high thermal conductivity member 26 is made of a material that is more flexible (less rigid) than the bearing sliding member 21. The highly flexible high thermal conductivity member may be made of a material such as an acrylic heat dissipation sheet or a heat dissipation silicone pad.
[0030] In this embodiment, the outer diameter of both axial ends of the bearing sliding member 21 is reduced, and circumferential grooves (recesses, notches) 21a and 21b are provided on the outer circumference of the ends of the bearing sliding member 21, and the high thermal conductivity member 26 is arranged in these grooves 21a and 21b.
[0031] As a result of the above configuration, grooves 21a and 21b are formed on the shaft end side of the bearing sliding member 21, making the wall thickness thinner. Since a flexible, high-thermal-conductivity member 26 with low rigidity is disposed in these grooves, the shaft end side of the bearing sliding member 21 becomes easily deformable. That is, when uneven contact occurs on the shaft end side of the bearing sliding member 21, and the force from this uneven contact acts on the bearing sliding member 21 from the inner circumference side, the bearing sliding member 21 becomes easily deformed. Therefore, when the shaft sleeve 13 makes strong contact with the end of the bearing sliding member 21 due to uneven contact or the like, the bearing sliding member 21 deforms and the contact force is reduced, so the amount of frictional heat generated can be kept to a minimum.
[0032] Furthermore, since the thermal conductivity of the high thermal conductivity member 26 is higher than that of the bearing sliding member 21, the frictional heat generated at the end of the bearing sliding member 21 can be efficiently dissipated to the back metal 22, thereby improving heat dissipation. In addition, the frictional heat generated at the end of the bearing sliding member 21 can also be dissipated from the annular high thermal conductivity member 27 to the back metal 22 and the bearing retainer 28, further improving heat dissipation.
[0033] As described above, according to this embodiment, even if uneven contact occurs with the bearing sliding member 21, the contact force is reduced, minimizing the amount of frictional heat generated, and the heat dissipation of frictional heat generated by sliding between the rotating shaft and the bearing sliding member 21 is improved, thereby reducing the temperature rise of the bearing sliding member 21. Therefore, by suppressing heat generation due to uneven contact of the rotating shaft 1 with the bearing device and improving heat dissipation, bearing damage due to excessive temperature rise of the bearing sliding member 21 can be suppressed, and a highly reliable vertical shaft pump, such as a pre-standby operation type vertical shaft pump, can be realized.
[0034] In this embodiment, the outer diameter of the axial end of the bearing sliding member 21 is reduced to form grooves 21a and 21b, and the high thermal conductivity member 26 is placed in these grooves 21a and 21b. However, the configuration may also be as follows: The inner diameter of the end of the back metal 22 corresponding to the axial end of the bearing sliding member 21 is increased, and a circumferential groove is provided on the inner circumference of the end of the back metal 22, and the high thermal conductivity member 26 is placed in this groove. Alternatively, the outer diameter of the axial end of the bearing sliding member 21 may be reduced, and the inner diameter of the axial end of the back metal 22 may also be increased, and the high thermal conductivity member 26 may be placed in the groove formed by these modifications.
[0035] Furthermore, by roughening or creating screw grooves on the surface of the bearing sliding member 21 or back metal 22 in contact with the high thermal conductivity member 26, the coefficient of contact friction with the high thermal conductivity member 26 can be increased, thereby suppressing the slippage of the high thermal conductivity member 26 against the bearing sliding member 21 or back metal 22 and improving ease of assembly.
[0036] As described above, this embodiment makes it possible to realize a vertical shaft pump that suppresses excessive temperature rise and bearing damage of the bearing due to heat generated at the sliding part between the bearing device and the rotating shaft. In other words, during idling operation when no water is being pumped, the frictional heat generated at the sliding part between the bearing device and the rotating shaft, especially at the axial end of the bearing sliding member 21, can be effectively dissipated, thereby suppressing the risk of excessive temperature rise and bearing damage of the bearing. [Examples]
[0037] Embodiment 2 of the vertical shaft pump of the present invention will be described with reference to Figure 1 and Figure 3. Figure 3 is an enlarged cross-sectional view of the main part of the bearing device in Embodiment 2, which corresponds to the bearing device 6 or 7 of the vertical shaft pump shown in Figure 1, and is the same figure as Figure 2 described above. In the description of Embodiment 2, the bearing device shown in Figure 3 will be described as the bearing device 7 shown in Figure 1, but the bearing device 6 has a similar configuration. Note that in Figure 3, only the right half of the bearing device 7 is shown, and the left half is omitted from the illustration. Also, parts that are denoted by the same reference numerals as in Figures 1 and 2 are the same or corresponding parts, so redundant explanations will be omitted, and the explanation will focus on the parts that differ from Embodiment 1.
[0038] In this embodiment 2, the back metal 22 is provided on the outer circumference of the bearing sliding member 21, similar to embodiment 1. However, in this embodiment 2, an elastic member 25 is provided so as to be in contact with the outer circumference of the axial center of the back metal 22 and the inner circumference of the bearing housing 23. Furthermore, the outer circumference of the end of the bearing sliding member 21 does not have grooves 21a, 21b or high thermal conductivity members 26 as shown in Figure 2. Instead, flexible high thermal conductivity members (high thermal conductivity flexible material) 26 (26a, 26b) are provided on the outer circumference of both axial ends of the bearing sliding member 21 via the back metal 22.
[0039] The high thermal conductivity member 26 is made of a material with higher thermal conductivity than the elastic member 25, which is positioned on the central outer circumference of the bearing sliding member 21 via the back metal 22. The heat generated in the bearing sliding member 21 is released to the bearing housing 23 side via the back metal 22 and the high thermal conductivity member 26.
[0040] In Figure 3, the high thermal conductivity member 26 is provided on both axial ends of the back metal 22, but it may also be provided only on the outer circumference of one end, or it may be provided only on either the upper or lower end, depending on the characteristics of the machine to which it is applied.
[0041] In this embodiment 2, as in embodiment 1, a flexible, annular, high-thermal-conductivity member (high-thermal-conductivity flexible material) 27 (27a, 27b) is provided so as to contact both the axial end face of the bearing sliding member 21 and the axial end face of the back metal 22. These annular, high-thermal-conductivity members 27 are held by a bearing retainer 28 attached to the bearing housing 23, or by a bearing retainer portion 23a integrally formed at the lower end of the bearing housing 23. At the same time, the bearing sliding member 21, the back metal 22, and the high-thermal-conductivity member 26 are also held by the bearing retainer 28 or the bearing retainer portion 23a.
[0042] The elastic member 25 is made of a material with lower rigidity than the material used for the back metal 22 and the bearing housing 23, and is preferably made of a rubber material such as nitrile rubber.
[0043] The high thermal conductivity member 26 and the annular high thermal conductivity member 27 may be made of a material such as an acrylic heat dissipation sheet or a heat dissipation silicone pad, as in Example 1. Furthermore, the high thermal conductivity member 26 and the annular high thermal conductivity member 27 should have a higher thermal conductivity than the material used for the bearing sliding member 21 and the elastic member 25, and lower rigidity than the material used for the back metal 22 and the elastic member 25. Regarding the selection of materials for the high thermal conductivity members 26 and 27, which are made of rubber material such as nitrile rubber (elastic member 25) or acrylic heat dissipation sheet or heat dissipation silicone pad, it is preferable to use hardness measured by an index such as Asker C as an index of rigidity. The other parts are the same as in Example 1 above, so their explanation will be omitted.
[0044] In this way, by providing the elastic member 25 so as to be in contact with the outer circumference of the axial center of the back metal 22 and the inner circumference of the bearing housing 23, when the axial upper or lower end of the bearing sliding member 21 and the shaft sleeve 13 come into particularly strong contact due to the inclination or deflection of the rotating shaft 1, the elastic member 25 deforms, making it easier for the back metal 22 to inclinate so that the center line of the back metal 22 coincides with the center line of the shaft sleeve 13. By inclining the back metal 22, the contact force between the axial upper or lower end of the bearing sliding member 21 and the shaft sleeve 13 is reduced.
[0045] In this embodiment, the back metal 22 is held by an elastic member 25 at its axial center and by a high-thermal-conductivity member 26, which has lower rigidity than the elastic member 25, at its axial end. This configuration makes it easier for the bearing sliding member 21 to tilt compared to when the back metal 22 is held by the elastic member 25 along its entire axial length. Consequently, uneven contact between the shaft sleeve 13 of the rotating shaft 1 and the bearing sliding member 21 can be reduced, thus reducing the generation of frictional heat from sliding.
[0046] Furthermore, since the high thermal conductivity member 26 is made of a material with a higher thermal conductivity than the elastic member 25, it has the effect of improving heat dissipation by dissipating the frictional heat generated in large quantities at the shaft end side of the bearing sliding member 21 due to uneven contact to the bearing housing 23 side via the back metal 22 and the high thermal conductivity member 26. In addition, since an annular high thermal conductivity member 27 is also provided, the frictional heat generated at the shaft end side of the bearing sliding member 21 can also be dissipated to the bearing retainer 28 side via the annular high thermal conductivity member 27. It should be noted that the annular high thermal conductivity member 27 is also made of a flexible material, similar to the high thermal conductivity member 26, so that the inclination of the bearing sliding member 21 and the back metal 22 is not obstructed.
[0047] As described above, in this embodiment 2, similar to embodiment 1, a vertical shaft pump can be obtained that suppresses excessive temperature rise and damage to the bearing due to heat generated at the sliding part between the bearing device and the rotating shaft. Furthermore, in this embodiment 2, since an elastic member 25 is provided between the central outer circumference of the back metal 22 and the bearing housing 23, when the rotating shaft 1 is tilted, the bearing sliding member 21 can also be tilted in accordance with the tilt of the rotating shaft 1, thereby reducing uneven contact and reducing the generation of frictional heat. In addition, the heat generated in the bearing sliding member 21 can be dissipated through the high thermal conductivity member 26 and the annular high thermal conductivity member 27, thereby improving heat dissipation and suppressing the temperature rise of the bearing sliding member 21, thus reducing the risk of bearing damage. Therefore, by adopting this embodiment, a highly reliable vertical shaft pump, such as a pre-operation type vertical shaft pump, can be realized.
[0048] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, although the embodiments described above included a bearing device with a back metal, the present invention can be similarly applied to bearing devices without a back metal. Furthermore, the present invention is not limited to vertical shaft pumps of the pre-standby operation type, and can be similarly applied to any vertical shaft pump equipped with a bearing device having a bearing sliding member that uses pumped water as a lubricant during pumping operation and can operate with unlubricated sliding without lubrication during idling operation. Furthermore, the embodiments described above are explained in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described. [Explanation of Symbols]
[0049] 1: Rotating shaft, 2: Impeller, 3: Pump casing, 3a: Suction bell mouth, 4: Pumping pipe, 5: Discharge elbow section, 6,7: Bearing device, 8: Coupling, 9: Water intake tank, 9a: Floor section, 10: Motor, 11: Guide vanes, 12: Support member, 13: Shaft sleeve, 15: Support base, 21: Bearing sliding member, 21a, 21b: Groove, 22: Back metal, 23: Bearing housing, 23a: Bearing retainer, 24: Bearing case, 25: Elastic member, 26, 26a, 26b: High thermal conductivity members, 27, 27a, 27b: Annular high thermal conductivity members, 28, 28a, 28b: Bearing retainer; 100: Vertical shaft pump.
Claims
1. A vertical shaft pump comprising a rotating shaft extending vertically, an impeller fixed to the lower end of the rotating shaft and rotating together with the rotating shaft, and a bearing device supporting the rotating shaft, The aforementioned bearing device uses the pumped water as a lubricant during pumping operation and can operate with unlubricated sliding during idling operation. A bearing sliding member is provided at the portion of the bearing device that supports the rotating shaft and that slides against the rotating shaft, and this bearing sliding member is housed in a bearing housing. A high thermal conductivity member is provided on the outer circumference of one or both axial ends of the bearing sliding member to release heat towards the bearing housing, and this high thermal conductivity member is made of a material with higher thermal conductivity than the material arranged on the central outer circumference of the bearing sliding member. A vertical shaft pump characterized by the following features.
2. A vertical shaft pump according to claim 1, A vertical shaft pump characterized in that the high thermal conductivity member is made of a highly thermal conductivity flexible material that is more flexible than the bearing sliding member.
3. A vertical shaft pump according to claim 2, A vertical shaft pump characterized in that the high thermal conductivity member is composed of either an acrylic heat dissipation sheet or a heat dissipation silicone pad.
4. A vertical shaft pump according to claim 1, A back metal is provided so as to be in contact with the outer circumference of the bearing sliding member, and the back metal is housed in the inner circumference of the bearing housing. A vertical shaft pump characterized in that the high thermal conductivity member is provided on the outer circumference of one or both axial ends of the bearing sliding member so as to be in contact with the bearing sliding member and the back metal.
5. A vertical shaft pump according to claim 2, A vertical shaft pump characterized in that a circumferential groove is provided on the outer circumference of the end of the bearing sliding member, and the high thermal conductivity member is disposed in this groove.
6. A vertical shaft pump according to claim 4, The aforementioned high thermal conductivity member is made of a highly thermal conductivity flexible material that is more flexible than the bearing sliding member. A vertical shaft pump characterized in that a circumferential groove is provided on the inner circumference of the end of the back metal, and the high thermal conductivity member is disposed in this groove.
7. A vertical shaft pump according to claim 4, A vertical shaft pump characterized by comprising an annular high thermal conductivity member provided so as to contact both the axial end face of the bearing sliding member and the axial end face of the back metal, and a retaining member attached to the back metal or the bearing housing to hold the annular high thermal conductivity member.
8. A vertical shaft pump according to claim 4, A vertical shaft pump characterized in that at least one surface of the bearing sliding member or the back metal in the portion that contacts the high thermal conductivity member is processed to increase the coefficient of contact friction with the high thermal conductivity member.
9. A vertical shaft pump comprising a rotating shaft extending vertically, an impeller fixed to the lower end of the rotating shaft and rotating together with the rotating shaft, and a bearing device supporting the rotating shaft, The aforementioned bearing device uses the pumped water as a lubricant during pumping operation and can operate with unlubricated sliding during idling operation. A bearing sliding member is provided at the portion of the bearing device that supports the rotating shaft and that slides against the rotating shaft, and this bearing sliding member is housed in a bearing housing. An elastic member is provided so as to be in contact with the outer circumference of the axial center of the bearing sliding member and the inner circumference of the bearing housing. A high thermal conductivity member is provided on the outer circumference of the axial end of the bearing sliding member. This member is made of a material with higher thermal conductivity than the elastic member located on the outer circumference of the central part of the bearing sliding member and is used to release the heat generated by the bearing sliding member towards the bearing housing. A vertical shaft pump characterized by the following features.
10. A vertical shaft pump according to claim 9, A vertical shaft pump characterized in that a back metal is provided on the outer circumference of the bearing sliding member, and the elastic member and the high thermal conductivity member are arranged so as to be in contact with the outer circumference of the back metal and the inner circumference of the bearing housing.
11. A vertical shaft pump according to claim 10, A vertical shaft pump characterized in that the high thermal conductivity member is made of a high thermal conductivity flexible material with lower rigidity than the elastic member.
12. A vertical shaft pump according to claim 11, A vertical shaft pump characterized by comprising an annular high thermal conductivity member provided so as to contact both the axial end face of the bearing sliding member and the axial end face of the back metal, and a bearing retainer attached to the bearing housing for holding the annular high thermal conductivity member and the bearing sliding member.
13. A vertical shaft pump according to claim 9, A vertical shaft pump characterized in that the elastic member is made of nitrile rubber, and the high thermal conductivity member is made of either an acrylic heat dissipation sheet or a heat dissipation silicone pad.
14. A vertical shaft pump according to claim 1 or 9, A vertical shaft pump characterized in that the high heat-conducting member is provided only on the side of the axial end of the bearing sliding member where the amount of heat generated by contact friction with the rotating shaft is greater.
15. A vertical shaft pump according to claim 1 or 9, A vertical shaft pump characterized in that the rotating shaft has a shaft sleeve provided at the portion that contacts the bearing sliding member.