Self-cooling centrifugal pump

Abstract

The self-cooling centrifugal pump comprises a pump shell and a motor, a flow channel is formed in the pump shell, and a liquid inlet and a liquid outlet which are communicated with the two ends of the flow channel respectively are formed in the pump shell; the motor is fixedly connected with the pump shell, the output end of the motor extends into the flow channel, a channel communicated with the flow channel is formed in the motor, the liquid inlet end of the channel is far away from the output end of the motor, and the liquid outlet end of the channel is close to the output end of the motor; a channel is formed in the motor, the liquid inlet end of the channel is far away from the output end of the motor, the liquid outlet end of the channel is close to the output end of the motor, and pressure difference is formed between the liquid inlet end and the liquid outlet end of the channel under centrifugal force so that liquid in the flow channel can be distributed into the channel. And the liquid flowing through the channel carries away heat energy in the motor and returns to the flow channel, so that efficient heat dissipation treatment on the motor is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal pumps, and particularly to a self-cooling centrifugal pump. Background Art

[0002] A centrifugal pump operates by using the rotation of an impeller to cause the water to undergo centrifugal motion. Before starting the pump, the pump casing and the suction pipe must be filled with water. Then, the motor is started, causing the pump shaft to drive the impeller and the water to rotate at high speed. The water undergoes centrifugal motion and is thrown towards the outer edge of the impeller, flowing into the pressure water pipeline of the pump through the flow channel of the volute pump casing. Among them, when the motor runs at high speed for a long time, a cooling structure needs to be equipped to ensure the stable operation of the motor.

[0003] For example, in the patent proposed by the patent with the application number CN202223014798.4, a sealing housing is fixedly installed on the outer surface of the motor of the centrifugal pump. A cooling device is provided on the outer surface of the sealing housing. The cooling device includes a cooling chamber for storing a coolant, and the coolant in the cooling chamber cools and dissipates heat from the motor of the centrifugal pump.

[0004] However, the above cooling pipeline is located outside the motor, resulting in poor cooling effect and complex structure. Summary of the Invention

[0005] In view of this, it is necessary to provide a self-cooling centrifugal pump to solve the problems that the cooling pipeline of the existing centrifugal pump is located outside the motor, with poor cooling effect and complex structure.

[0006] The present invention provides a self-cooling centrifugal pump, including a pump casing and a motor. A flow channel is formed in the pump casing, and a liquid inlet and a liquid outlet are provided on the pump casing, respectively communicating with both ends of the flow channel. The motor is fixedly connected to the pump casing, and the output end of the motor extends into the flow channel. A channel communicating with the flow channel is formed in the motor. The liquid inlet end of the channel is arranged far from the output end of the motor, and the liquid outlet end of the channel is arranged close to the output end of the motor. A pressure difference is formed between the liquid inlet end and the liquid outlet end of the channel under centrifugal force to allow the liquid in the flow channel to be diverted into the channel.

[0007] Further, the motor includes a housing, a rotating shaft, two bearing assemblies, a rotor assembly, a stator assembly, and an impeller. The housing is fixedly connected to the pump casing. The rotating shaft is rotatably connected to the housing via the two bearing assemblies. The end of the rotating shaft extends into the flow channel and is connected to the impeller. The rotor assembly is connected to the rotating shaft. The two bearing assemblies are respectively arranged on both sides of the rotor assembly. The stator assembly is fixedly connected to the housing and is arranged opposite to the rotor assembly. The channel is formed among the housing, the rotating shaft, the two bearing assemblies, the rotor assembly, and the stator assembly.

[0008] Further, a first cooling channel is formed inside the bearing assembly near the impeller, a second cooling channel is formed between the rotor assembly and the stator assembly, a third cooling channel is formed inside the bearing assembly far from the impeller, a fourth cooling channel is formed inside the side of the housing far from the impeller, and a fifth cooling channel is formed inside the rotating shaft. One end of the first cooling channel, the second cooling channel, the third cooling channel, the fourth cooling channel, and one end of the fifth cooling channel are connected in sequence. The other end of the first cooling channel forms the liquid inlet end of the channel, and the other end of the fifth cooling channel forms the liquid outlet end of the channel.

[0009] Further, both of the bearing assemblies include a shaft sleeve, a spacer sleeve, a thrust disc, a bearing housing, and a radial thrust bearing lining. The shaft sleeve and the spacer sleeve are both installed on the rotating shaft. One of the spacer sleeves abuts against the boss of the rotating shaft, and the other spacer sleeve is connected to the rotor assembly. The bearing housing is fixedly connected to the housing. The radial thrust bearing lining is installed at the position between the shaft sleeve and the bearing housing. The thrust disc is installed on the shaft sleeve and is located at the position between the radial thrust bearing lining and the spacer sleeve. The first cooling channel and the third cooling channel are formed among the shaft sleeve, the thrust disc, and the radial thrust bearing lining.

[0010] Further, the rotor assembly includes a support plate, a plurality of permanent magnets, a plurality of rotor cores, and a plurality of first watertight covers. The support plate is annular, and a stepped portion for mating connection with the rotating shaft is provided at its inner circle. The plurality of permanent magnets and the plurality of rotor cores are respectively installed in a plurality of installation grooves provided on the support plate. The plurality of first watertight covers are respectively connected to the ports of the plurality of installation grooves for closing the installation grooves. The second cooling channel is formed between the support plate and the inner wall of the housing and the stator assembly.

[0011] Further, the stator assembly includes a first stator group and a second stator group. Two stator slots are formed on the inner wall of the housing on both sides of the support plate. The two stator slots are arranged opposite to the plurality of installation grooves. The first stator group and the second stator group are respectively installed in the two stator slots. The stator assembly further includes a second watertight cover installed at the port of the stator slot for closing the stator slot.

[0012] Further, the motor further includes a cooling end cover, which is fixedly connected to the side of the housing away from the pump housing, and a fourth cooling channel is formed therebetween. A through hole coaxial with the rotating shaft is formed inside the rotating shaft, and the through hole is the fifth cooling channel. One end of the through hole is communicated with the fourth cooling channel, and the other end of the through hole passes through the impeller and is communicated with the flow channel.

[0013] Further, an absorption chamber and a drainage chamber are formed inside the pump housing. The side of the pump housing close to the motor is recessed inward to form a driving chamber with the motor. The absorption chamber, the driving chamber, and the drainage chamber are communicated in sequence. The output end of the motor is located in the driving chamber. The liquid inlet end and the liquid outlet end of the channel are both communicated with the channel.

[0014] Further, a bearing wear monitoring sensor is further included. The bearing wear monitoring sensor is installed on the stator assembly and is used to detect the axial and radial wear of the rotor assembly.

[0015] Further, the bearing wear monitoring sensor includes a first radial monitoring coil, a second radial monitoring coil, a first axial monitoring coil, and a second axial monitoring coil arranged in sequence along the circumferential direction of the rotor assembly. The first radial monitoring coil and the second radial monitoring coil are electrically connected, and the first axial monitoring coil and the second axial monitoring coil are electrically connected.

[0016] Compared with the prior art, the output end of the motor acts on the pump housing, so as to form a centrifugal force acting on the liquid in the flow channel, so that the liquid flowing in from the liquid inlet is discharged from the liquid outlet under the action of the centrifugal force. At the same time, a channel is formed inside the motor, and the liquid inlet end of the channel is arranged away from the output end of the motor, and the liquid outlet end of the channel is arranged close to the output end of the motor. A pressure difference is formed between the liquid inlet end and the liquid outlet end of the channel under the centrifugal force, so that the liquid in the flow channel is diverted into the channel. The liquid flowing through the channel carries away the heat energy inside the motor and returns to the flow channel, thereby realizing efficient heat dissipation treatment of the motor. At the same time, since the liquid in the flow channel is used, no external cooling pipeline is required, and the cooling structure is simplified. Description of the Drawings

[0017] Figure 1 Schematic diagram of the overall external structure of the self-cooling centrifugal pump provided by the embodiment of the present invention; Figure 2 Schematic diagram of the overall internal structure of the self-cooling centrifugal pump provided by the embodiment of the present invention; Figure 3 For Figure 2 Schematic diagram of the liquid flow structure in the motor Figure 4 For Figure 2 Schematic diagram of the housing structure in Figure 5 is Figure 2 a schematic structural view of the central rotating shaft; Figure 6 is Figure 2 a schematic structural view of the central bearing assembly; Figure 7 is Figure 2 a schematic structural view of the central rotor assembly and the stator assembly; Figure 8 is Figure 7 a schematic structural view of the central support plate; Figure 9 is Figure 2 a schematic structural view of the central liquid guide cavity; Figure 10 is Figure 2 a schematic structural view of the central liquid discharge port; Figure 11 is Figure 2 a schematic layout view of the first radial monitoring coil and the second radial monitoring coil; Figure 12 is Figure 2 a schematic layout view of the first axial monitoring coil and the second axial monitoring coil; Figure 13 is Figure 2 a schematic structural view of the impeller. Specific Embodiments

[0018] The following specifically describes the preferred embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings form a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, and are not used to limit the scope of the present invention.

[0019] As Figures 1-3 shown, a self-cooling centrifugal pump provided by an embodiment of the present invention includes a pump casing 100 and a motor 200. A flow channel 110 is formed in the pump casing 100. A liquid inlet 120 and a liquid outlet 130 are provided on the pump casing 100 and are respectively communicated with both ends of the flow channel 110. The motor 200 is fixedly connected to the pump casing 100. The output end of the motor 200 extends into the flow channel 110, and a channel communicating with the flow channel 110 is formed in the motor 200. The liquid inlet end of the channel is arranged far from the output end of the motor 200, and the liquid outlet end of the channel is arranged close to the output end of the motor 200. A pressure difference is formed between the liquid inlet end and the liquid outlet end of the channel under centrifugal force to supply the liquid in the flow channel 110 to be diverted into the channel.

[0020] During implementation, the output end of the motor 200 acts on the pump housing 100, thereby forming a centrifugal force acting on the liquid within the flow channel 110, causing the liquid flowing in from the liquid inlet 120 to be discharged from the liquid outlet 130 under the action of the centrifugal force. Meanwhile, a channel is formed inside the motor 200, and the liquid inlet end of the channel is arranged far away from the output end of the motor 200, while the liquid outlet end of the channel is arranged close to the output end of the motor 200. A pressure difference is formed between the liquid inlet end and the liquid outlet end of the channel under the centrifugal force, so that the liquid in the flow channel 110 is diverted into the channel. The liquid flowing through the channel carries away the heat energy inside the motor 200 and returns to the flow channel 110, thereby realizing efficient heat dissipation treatment for the motor 200. At the same time, since it uses the liquid in the flow channel 110, there is no need for an external cooling pipeline, simplifying the cooling structure.

[0021] In the pump housing 100 of this embodiment, a flow channel 110 is formed, and a liquid inlet 120 and a liquid outlet 130 that are respectively communicated with both ends of the flow channel 110 are opened on the pump housing 100. The liquid introduced into the flow channel 110 from the liquid inlet 120 can flow along the flow channel 110 under the action of the output end of the motor 200 and is discharged from the liquid outlet 130.

[0022] In one embodiment, a liquid suction chamber 111 and a liquid discharge chamber 113 are formed inside the pump housing 100. The side of the pump housing 100 close to the motor 200 is recessed inward to form a driving chamber 112 with the motor 200. The liquid suction chamber 111, the driving chamber 112, and the liquid discharge chamber 113 are sequentially communicated. The output end of the motor 200 is located in the driving chamber 112, and both the liquid inlet end and the liquid outlet end of the channel are communicated with the channel.

[0023] Among them, the liquid inlet 120 is formed at the top of the liquid suction chamber 111, and the liquid outlet 130 is formed at the top of the liquid discharge chamber 113. It can be understood that the heights of the above-mentioned liquid inlet 120 and liquid outlet 130 are both higher than the output end of the motor 200, which can ensure that after each shutdown of the centrifugal pump, the output end of the motor 200 is immersed in the liquid, ensuring that the centrifugal pump can effectively self-prime during the next startup.

[0024] Among them, such as Figures 9-10 Both the liquid suction chamber 111 and the liquid discharge chamber 113 are vertically arranged, and the driving chamber 112 is arranged at the bottom of the liquid discharge chamber 113. To communicate the liquid suction chamber 111 and the driving chamber 112, a liquid guiding chamber 112a that communicates the liquid suction chamber 111 and the driving chamber 112 is formed inside the pump housing 100. A liquid discharge port 112b that communicates with the liquid discharge chamber 113 is opened at the top of the driving chamber 112. Meanwhile, a waste discharge port 112c is opened at the bottom of the driving chamber 112, and a waste discharge valve is provided at the waste discharge port 112c for convenient regular cleaning.

[0025] In the present implementation, the motor 200 is fixedly connected to the pump housing 100. The output end of the motor 200 extends into the flow channel 110, and a channel communicating with the flow channel 110 is formed inside the motor 200. The liquid inlet end of the channel is arranged far from the output end of the motor 200, and the liquid outlet end of the channel is arranged close to the output end of the motor 200. A pressure difference is formed between the liquid inlet end and the liquid outlet end of the channel under centrifugal force to supply the liquid in the flow channel 110 to be diverted into the channel.

[0026] A channel for the heat dissipation medium to flow through is formed inside the motor 200, and the positions of the liquid inlet end and the liquid outlet end of the channel are defined, so that the liquid in the flow channel 110 is diverted into the channel under centrifugal force, thereby carrying the heat energy generated inside the motor 200 during operation.

[0027] In one embodiment, the motor 200 includes a housing 210, a rotating shaft 220, two bearing assemblies 230, a rotor assembly 240, a stator assembly 250, and an impeller 260. The housing 210 is fixedly connected to the pump housing 100. The rotating shaft 220 is rotatably connected to the housing 210 via the two bearing assemblies 230. The end of the rotating shaft 220 extends into the flow channel 110 and is connected to the impeller 260. The rotor assembly 240 is connected to the rotating shaft 220. The two bearing assemblies 230 are respectively arranged on both sides of the rotor assembly 240. The stator assembly 250 is fixedly connected to the housing 210 and is arranged opposite to the rotor assembly 240. A channel is formed among the housing 210, the rotating shaft 220, the two bearing assemblies 230, the rotor assembly 240, and the stator assembly 250.

[0028] In the present implementation, the pump housing 100 and the housing 210 are integrated, and no coupling is required for transmission, avoiding vibration and abnormal noise caused by misalignment of the shafting. At the same time, the overall structure of this centrifugal pump is more compact, reducing the volume and weight of the centrifugal pump, shrinking the space occupied by the overall structure, facilitating installation in narrow spaces such as ship engine rooms, and improving practicality. It should be noted that the housing 210 and the pump housing 100 can be connected by bolts, and a sealing ring is provided on the docking surface between the two.

[0029] Among them, a first cooling channel 21a is formed inside the bearing assembly 230 close to the impeller 260, a second cooling channel 21b is formed between the rotor assembly 240 and the stator assembly 250, a third cooling channel 21c is formed inside the bearing assembly 230 far from the impeller 260, a fourth cooling channel 21d is formed inside the housing 210 on the side far from the impeller 260, and a fifth cooling channel 21e is formed inside the rotating shaft 220. One end of the first cooling channel 21a, the second cooling channel 21b, the third cooling channel 21c, the fourth cooling channel 21d, and one end of the fifth cooling channel 21e are connected in sequence. The other end of the first cooling channel 21a forms the liquid inlet end of the channel, and the other end of the fifth cooling channel 21e forms the liquid outlet end of the channel.

[0030] To form the above-mentioned first cooling channel 21a and third cooling channel 21c, in one embodiment, as Figure 6 shown, both bearing assemblies 230 include a bushing 231, a spacer sleeve 232, a thrust disk 233, a bearing housing 234, and a radial-thrust bearing lining 235. The bushing 231 and the spacer sleeve 232 are both mounted on the rotating shaft 220. One spacer sleeve 232 abuts against the boss 221 of the rotating shaft 220, as Figure 5 shown. The other spacer sleeve 232 is connected to the rotor assembly 240. The bearing housing 234 is fixedly connected to the housing 210. The radial-thrust bearing lining 235 is installed at the position between the bushing 231 and the bearing housing 234. The thrust disk 233 is installed on the bushing 231 and is located at the position between the radial-thrust bearing lining 235 and the spacer sleeve 232. The first cooling channel 21a and the third cooling channel 21c are formed among the bushing 231, the thrust disk 233, and the radial-thrust bearing lining 235.

[0031] To form the above-mentioned second cooling channel 21b, in one embodiment, as Figures 7-8 shown, the rotor assembly 240 includes a support plate 241, a plurality of permanent magnets 242, a plurality of rotor cores 243, and a plurality of first watertight covers 244. The support plate 241 is annular, and a stepped portion 241b for mating connection with the rotating shaft 220 is provided at its inner ring. The plurality of permanent magnets 242 and the plurality of rotor cores 243 are respectively installed in a plurality of mounting grooves 241a formed on the support plate 241. The plurality of first watertight covers 244 are respectively connected at the ports of the plurality of mounting grooves 241a to close the mounting grooves 241a. The second cooling channel 21b is formed between the support plate 241 and the inner wall of the housing 210 and the stator assembly 250. By providing the first watertight covers 244, the permanent magnets and the rotor cores 243 are sealed in the mounting grooves 241a, extending the service life.

[0032] In one embodiment, as Figure 7 shown, the stator assembly 250 includes a first stator group and a second stator group. Two stator slots are formed on the inner wall of the housing 210 on both sides of the support plate 241. The two stator slots are arranged opposite to the plurality of mounting grooves 241a. The first stator group and the second stator group are respectively installed in the two stator slots. The stator assembly 250 further includes a second watertight cover 251 installed at the port of the stator slot to close the stator slot. By the second watertight cover 251, the stator assembly 250 is sealed in the stator cavity, avoiding fluid erosion of the stator assembly 250 and extending the service life of the stator assembly 250.

[0033] It should be noted that a gap needs to be reserved between the stator assembly 250 and the rotor assembly 240, so that the fluid in the flow channel 110 can flow to the side of the flow channel 110 far from the rotating shaft 220 after passing through the gaps between the inner and outer rings of the bearing assembly 230 and the gap between the stator assembly 250 and the rotor assembly 240 in sequence, realizing the cooling of the motor 200 and the lubrication of the bearing assembly 230. It should be noted that the gap reserved between the stator assembly 250 and the rotor assembly 240 is the air gap between the stator and rotor of the axial flux motor 200. The larger the power, the larger the air gap, usually 0.5 to 5 millimeters. In addition, a temperature sensor is provided in the stator cavity to monitor the temperature of the stator assembly 250.

[0034] As Figure 4 shown, in one embodiment, to form the above-mentioned fourth cooling channel 21d and fifth cooling channel 21e, the motor 200 further includes a cooling end cover 211. The cooling end cover 211 is fixedly connected to the side of the housing 210 far from the pump housing 100, and a fourth cooling channel 21d is formed therebetween. A through hole coaxially arranged with the rotating shaft 220 is opened inside the rotating shaft 220, and the through hole is the fifth cooling channel 21e. One end of the through hole is communicated with the fourth cooling channel 21d, and the other end of the through hole passes through the impeller 260 and is communicated with the flow channel 110.

[0035] It can be understood that to facilitate the installation of the above-mentioned multiple components, the housing 210 includes a first housing 212 and a second housing 213. The first housing 212 is connected to the pump housing 100, and the second housing 213 is fixedly connected to the cooling end cover 211. Both the first housing 212 and the second housing 213 are annular structures. After the components are installed, the first housing 212 and the second housing 213 can be fixedly connected by connecting screws.

[0036] In one embodiment, as Figure 13 shown, the impeller 260 includes an installation sleeve 261, a first wheel plate 262, a second wheel plate 263, and a plurality of blades 264. One end of the rotating shaft 220 extends into the installation sleeve 261 and is fixedly connected to the installation sleeve 261. The first wheel plate 262 and the second wheel plate 263 are arranged in parallel and sleeved on the installation sleeve 261. The plurality of blades 264 are uniformly arranged along the circumferential direction of the installation sleeve 261 between the first wheel plate 262 and the second wheel plate 263.

[0037] It should be noted that during the manufacturing and assembly of the pump unit, the above-mentioned components should be manufactured first, and the stator assembly 250 and the rotor assembly 240 of the motor 200 should be assembled in place. Then, the rotating shaft 220, the bearing assembly 230, and the impeller 260 of the motor 200 should be installed in place and locked. Finally, the whole is installed in the drive cavity 112 of the pump housing 100.

[0038] For the motor 200, the stator core, winding, winding coils thereon, and position and temperature sensors should be installed in the stator cavity first. Then, the second watertight cover plate 251 should be installed in the stator slots by welding or other means, while ensuring that the second watertight cover plate 251 is in close contact with the surfaces of the stator core and winding. By using this encapsulation process, it can be ensured that while the stator assembly 250 is cooled by pumped liquid, the winding is isolated from the external pumped liquid. After installation, the stator cavity is filled with a highly thermally conductive sealant to fill the space in the stator cavity except for the stator core and winding.

[0039] For the rotor assembly 240 of the motor 200, first, the rotor core 243 of the motor 200 is installed on both sides of the support plate 241 respectively, keeping the three coaxial. Then, permanent magnets are installed on the outer surface of the rotor core 243, and the first watertight cover plate 244 is welded or installed by other means on the ports of the installation slots 241a of the support plate 241 respectively to complete the encapsulation of the rotor core 243 and the magnets. After encapsulation, glue is poured into the installation slots 241a and the glue injection holes are blocked to complete the production of the rotor assembly 240 of the motor 200.

[0040] This embodiment also includes a bearing wear monitoring sensor, which is installed on the stator assembly 250 and is used to detect the axial and radial wear of the rotor assembly 240. When the bearing assembly 230 wears, the rotor assembly 240 will shift along the radial or axial position. These small displacements are monitored by 4 monitoring coils embedded in the stator assembly 250. By connecting each group of coils in series and measuring the induced electromotive force at both ends, accurate readings of the wear of the bearing assembly 230 in two directions can be achieved.

[0041] In one embodiment, as Figures 11-12 shown, the bearing wear monitoring sensor includes a first radial monitoring coil 310, a second radial monitoring coil 320, a first axial monitoring coil 330, and a second axial monitoring coil 340 arranged in sequence along the circumferential direction of the rotor assembly 240. The first radial monitoring coil 310 and the second radial monitoring coil 320 are electrically connected, and the first axial monitoring coil 330 and the second axial monitoring coil 340 are electrically connected.

[0042] When the bearing assembly 230 has no radial wear, the rotor assembly 240 is aligned with the stator assembly 250. The induced electromotive forces of the first radial monitoring coil 310 and the second radial monitoring coil 320 are equal in magnitude and opposite in direction. When the two coils are connected in series, the induced electromotive forces cancel each other out, and at this time, the radial monitoring reading of the bearing assembly 230 is 0. When the bearing assembly 230 has radial wear, the rotor assembly 240 vertically downwardly offsets relative to the stator assembly 250. The induced electromotive force of the first radial monitoring coil 310 decreases, and the induced electromotive force of the second radial monitoring coil 320 increases. At this time, the absolute value of the radial monitoring reading of the bearing assembly 230 is greater than 0, and the greater the absolute value of the reading, the more serious the radial wear of the bearing assembly 230.

[0043] When the bearing assembly 230 has no axial wear, the rotor assembly 240 is located in the middle of the two stator assemblies 250. The induced electromotive forces of the first axial monitoring coil 330 and the second axial monitoring coil 340 are equal in magnitude and opposite in direction. When the two coils are connected in reverse series, the induced electromotive force at this time is the initial value of the axial monitoring reading of the bearing assembly 230. When the bearing assembly 230 has axial wear, the rotor assembly 240 moves forward or backward relative to the stator assembly 250: If it is a forward displacement, the induced electromotive forces of the first axial monitoring coil 330 and the second axial monitoring coil 340 increase, and at this time, the axial monitoring reading of the bearing assembly 230 is greater than the initial value; if it is a backward displacement, the induced electromotive forces of the first axial monitoring coil 330 and the second axial monitoring coil 340 decrease, and at this time, the axial monitoring reading of the bearing assembly 230 is less than the initial value. The greater the difference between the axial monitoring reading of the bearing assembly 230 and the initial value, the more serious the axial wear of the bearing assembly 230.

[0044] Compared with the prior art: By the output end of the motor 200 acting on the pump housing 100, a centrifugal force acting on the liquid is formed in the flow channel 110, so that the liquid flowing in from the liquid inlet 120 is discharged from the liquid outlet 130 under the action of the centrifugal force. At the same time, a channel is formed inside the motor 200, and the liquid inlet end of the channel is arranged far from the output end of the motor 200, and the liquid outlet end of the channel is arranged close to the output end of the motor 200. A pressure difference is formed between the liquid inlet end and the liquid outlet end of the channel under the centrifugal force to supply the liquid in the flow channel 110 to be diverted into the channel. The liquid flowing through the channel carries away the heat energy inside the motor 200 and returns to the flow channel 110, thereby realizing efficient heat dissipation treatment of the motor 200. At the same time, since it uses the liquid in the flow channel 110, there is no need for an external cooling pipeline, simplifying the cooling structure.

[0045] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A self-cooling centrifugal pump, characterized in that, Comprising: A pump housing in which a flow passage is formed, and a liquid inlet and a liquid outlet are provided on the pump housing and communicate with both ends of the flow passage respectively; A motor fixedly connected to the pump housing, the output end of the motor extending into the flow passage, and a passage communicating with the flow passage is formed in the motor. The liquid inlet end of the passage is arranged away from the output end of the motor, and the liquid outlet end of the passage is arranged close to the output end of the motor. A pressure difference is formed between the liquid inlet end and the liquid outlet end of the passage under centrifugal force to supply the liquid in the flow passage to be diverted into the passage.

2. The self-cooling centrifugal pump according to claim 1, wherein, The motor includes a housing, a rotating shaft, two bearing assemblies, a rotor assembly, a stator assembly and an impeller. The housing is fixedly connected to the pump housing. The rotating shaft is rotatably connected to the housing via the two bearing assemblies. The end of the rotating shaft extends into the flow passage and is connected to the impeller. The rotor assembly is connected to the rotating shaft. The two bearing assemblies are respectively arranged on both sides of the rotor assembly. The stator assembly is fixedly connected to the housing and is arranged opposite to the rotor assembly. The passage is formed among the housing, the rotating shaft, the two bearing assemblies, the rotor assembly and the stator assembly.

3. The self-cooling centrifugal pump according to claim 2, characterized in that, A first cooling passage is formed in the bearing assembly close to the impeller. A second cooling passage is formed between the rotor assembly and the stator assembly. A third cooling passage is formed in the bearing assembly away from the impeller. A fourth cooling passage is formed inside the housing on the side away from the impeller. A fifth cooling passage is formed inside the rotating shaft. One end of the first cooling passage, the second cooling passage, the third cooling passage, the fourth cooling passage and one end of the fifth cooling passage are sequentially communicated. The other end of the first cooling passage forms the liquid inlet end of the passage. The other end of the fifth cooling passage forms the liquid outlet end of the passage.

4. The self-cooling centrifugal pump according to claim 3, characterized in that, Both of the two bearing assemblies include a shaft sleeve, a spacer sleeve, a thrust plate, a bearing seat and a radial thrust bearing lining. The shaft sleeve and the spacer sleeve are both mounted on the rotating shaft. One of the spacer sleeves abuts against the boss of the rotating shaft, and the other spacer sleeve is connected to the rotor assembly. The bearing seat is fixedly connected to the housing. The radial thrust bearing lining is mounted at the position between the shaft sleeve and the bearing seat. The thrust plate is mounted on the shaft sleeve and is located at the position between the radial thrust bearing lining and the spacer sleeve. The first cooling passage and the third cooling passage are formed among the shaft sleeve, the thrust plate and the radial thrust bearing lining.

5. The self-cooling centrifugal pump according to claim 3, characterized in that, The rotor assembly includes a support plate, a plurality of permanent magnets, a plurality of rotor cores and a plurality of first watertight covers. The support plate is annular, and a stepped portion for mating connection with the rotating shaft is provided at its inner circle. The plurality of permanent magnets and the plurality of rotor cores are respectively mounted in a plurality of mounting grooves formed on the support plate. The plurality of first watertight covers are respectively connected to the ports of the plurality of mounting grooves to close the mounting grooves. The second cooling passage is formed between the support plate and the inner wall of the housing and the stator assembly.

6. The self-cooling centrifugal pump according to claim 5, characterized in that, The stator assembly includes a first stator group and a second stator group. Two stator slots are formed on the inner wall of the housing on both sides of the support plate. The two stator slots are arranged opposite to a plurality of the mounting slots. The first stator group and the second stator group are respectively installed in the two stator slots. The stator assembly further includes a second watertight cover plate installed at the port of the stator slot for closing the stator slot.

7. The self-cooling centrifugal pump according to claim 3, characterized in that, The motor further includes a cooling end cover. The cooling end cover is fixedly connected to the side of the housing away from the pump housing, and a fourth cooling channel is formed therebetween. A through hole coaxially arranged with the rotating shaft is formed inside the rotating shaft. The through hole is the fifth cooling channel. One end of the through hole is communicated with the fourth cooling channel, and the other end of the through hole passes through the impeller and is communicated with the flow channel.

8. The self-cooling centrifugal pump according to claim 1, characterized in that, An absorption chamber and a drainage chamber are formed inside the pump housing. The side of the pump housing close to the motor is recessed inward to form a driving chamber with the motor. The absorption chamber, the driving chamber and the drainage chamber are communicated in sequence. The output end of the motor is located in the driving chamber. The liquid inlet end and the liquid outlet end of the channel are both communicated with the channel.

9. The self-cooling centrifugal pump according to claim 2, wherein, It further includes a bearing wear monitoring sensor. The bearing wear monitoring sensor is installed on the stator assembly for detecting the axial and radial wear of the rotor assembly.

10. The self-cooling centrifugal pump according to claim 9, characterized in that, The bearing wear monitoring sensor includes a first radial monitoring coil, a second radial monitoring coil, a first axial monitoring coil and a second axial monitoring coil arranged in sequence along the circumferential direction of the rotor assembly. The first radial monitoring coil and the second radial monitoring coil are electrically connected. The first axial monitoring coil and the second axial monitoring coil are electrically connected.

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