CN117167289A - Extensible miniature multistage shielding pump - Google Patents

Abstract

The application relates to the technical field of shielding pumps, in particular to an expandable miniature multistage shielding pump, which comprises a supporting cylinder body, wherein an interlayer channel for liquid to flow is formed in the cylinder wall of the supporting cylinder body; the wall surface of the inner cavity of the supporting cylinder body is coaxially fixedly connected with a stator, a main shaft is coaxially rotatably arranged in the inner cavity of the supporting cylinder body, a rotor matched with the stator is arranged on the main shaft, and an overcurrent gap is formed between the stator and the rotor; the main shaft is fixed on a bearing in the shell, and a plurality of impellers for driving liquid to work are arranged on the main shaft; the components of the expandable miniature multistage canned motor pump jointly form a plurality of flow passages, a plurality of surfaces of the motor are wrapped by the flow passages, the heat dissipation performance is greatly improved, and the expandable miniature multistage canned motor pump can be overlapped with multistage impellers according to requirements so as to achieve the required performance.

Description

Extensible miniature multistage shielding pump

Technical Field

The application relates to the technical field of shielding pumps, in particular to an expandable miniature multistage shielding pump.

Background

With the rapid development of modern electronic technology, special electronic equipment in the fields of 5G base stations, radar thermal control systems, marine ships, aircraft platforms and the like is more and more integrated and power-increased, the power of the electronic equipment is more and more increased, the heat loss of the electronic equipment is also increased, and the cooling requirement of the traditional air cooling is difficult to meet.

Compared with the traditional air cooling heat dissipation, the liquid cooling heat dissipation capability is stronger, and is a necessary trend of heat dissipation of high-end electronic equipment. The pump is used as a core component for driving the liquid working medium to circulate and corresponds to the heart of human blood circulation, however, the size of the pump becomes a big obstacle for the application of the pump in the fields.

The bearing system of the common micropump is communicated with the liquid cavity, so that lubricating oil in the bearing system is diluted by working liquid, the lubricating capability is lost, the axle center directly rubs with the bearing, and the service life and noise of the pump are greatly deteriorated. Most of the prior solutions adopt a dynamic sealing mode, and a packing or a sealing ring is used for separating the bearing from the fluid, but the sealing capability of the mode is poor, and the friction between a shaft and a sealing element can reduce the driving force of a motor to the output of an impeller, so that the performance of the micro pump is greatly reduced.

The ball bearing used in the micropump in the prior art is characterized in that spherical alloy steel balls are arranged between an inner steel ring and an outer steel ring, lubricating grease is filled in the middle of the inner steel ring and the outer steel ring, and friction force in the power transmission process is reduced and mechanical power transmission efficiency is improved in a rolling mode. However, the ball bearing has the following disadvantages that firstly, when the ball bearing is applied to the micro pump for long-term operation, lubricating grease of the ball bearing is easy to wash away in water, so that the ball bearing is invalid; second, the ball bearing life is lower due to wear; third, due to wear, noise is loud.

Meanwhile, the performance of the existing miniature shielding pump cannot meet the working conditions of high lift because of pursuing small volume, and the size of the multi-stage shielding pump meeting the high lift is too large.

Therefore, we propose an expandable micro multistage canned motor pump to solve the above problems.

Disclosure of Invention

An expandable miniature multistage canned motor pump comprises a housing, a bearing structure assembly, a main shaft, an impeller body and a motor body. The shell is provided with a water inlet for liquid to flow in and a water outlet for liquid to flow out. The bearing structure assembly comprises a bearing and a bearing seat, and the bearing seat is fixed on the shell. The spindle is supported on a bearing. The impeller main body comprises a head impeller fixed at the end of the main shaft close to the water inlet and a plurality of tail impellers fixed at the end of the main shaft close to the water outlet. The motor body includes a rotor assembly secured to the main shaft and a stator assembly secured within the housing.

Further, the housing includes a water inlet end, a support cylinder and a water outlet end. The water inlet end is coaxially connected with the front end of the supporting cylinder, the water outlet end is coaxially connected with the rear end of the supporting cylinder, the water outlet end comprises a connecting section matched with the tail impeller and a water outlet section provided with a water outlet discharge port, the connecting section and the water outlet section are coaxially connected, mutually matched clamping grooves are formed among the water inlet end, the supporting cylinder, the connecting section and the water outlet section, the mutually matched clamping grooves are fixed through threads or welding in a sealing manner, and the connecting section is in sustainable superposition through the mutually matched clamping grooves.

Further, a water inlet for fluid inflow and communicated with the head impeller is formed in the water inlet end; the wall of the supporting cylinder body is provided with an interlayer channel for liquid to flow; the connecting section in the water outlet end is provided with a runner which is communicated with the interlayer channel and the tail impeller, the water outlet section in the water outlet end is provided with a water outlet which is communicated with the tail impeller and is used for flowing out liquid, and the connecting section and the water outlet section are both provided with necking structures for converging fluid.

Further, the bearing assembly is a hydraulic floating bearing assembly, the hydraulic floating bearing assembly comprises a hydraulic floating bearing seat fixed on the shell and a hydraulic floating bearing body fixed on the main shaft, a through hole for liquid circulation is formed in the hydraulic floating bearing seat, an eight-shaped groove is formed in the matching surface of the hydraulic floating bearing body and the hydraulic floating bearing seat and used for generating a high-pressure liquid film when rotating at a high speed, supporting the main shaft to suspend and lubricate and cool the main shaft, and the higher the rotating speed of the rotor is, the stronger the rigidity of the bearing is.

Furthermore, the bearing structure assembly adopts a high-speed ball bearing assembly, the ball bearing assembly comprises a ball bearing seat fixed on the shell and a ball bearing body for supporting the main shaft, a through hole for liquid to circulate is formed in the ball bearing seat, and the ball bearing body is a miniature precise ceramic high-speed angular contact bearing, so that the bearing assembly can be suitable for occasions with high rotating speed, intermittent working and more start and stop times; meanwhile, due to the interference fit between the ball bearing body and the ball bearing seat as well as between the ball bearing body and the main shaft, the generated interference force can better resist the generated axial force. The ball bearing body has the self-lubricating property of a conveying medium, lubricating grease is not required to be filled in the middle, the condition that the lubricating grease of a common metal ball bearing fails and the conveying medium is polluted is avoided, the wear resistance of a ceramic material is improved, and the service life and the reliability of a bearing system are greatly improved.

Further, the bearing structure assembly adopts a sliding bearing assembly, the sliding bearing assembly comprises a sliding bearing seat fixed on the shell and a sliding bearing body for supporting the main shaft, a through hole for liquid to circulate is formed in the sliding bearing seat, the outer wall of the sliding bearing is installed on the sliding bearing seat in an interference manner, a plurality of spiral channels are formed in the inner wall of the sliding bearing, the main shaft is supported on the inner wall of the sliding bearing, and the liquid flows into the spiral channels to lubricate the sliding bearing, so that friction is reduced; the sliding bearing body is made of special graphite or silicon carbide material and has self-lubricating property.

Furthermore, when the bearing structure assembly adopts a hydraulic floating bearing assembly or a sliding bearing assembly, a thrust disc is additionally arranged behind some bearing assemblies in order to solve the damage of axial force to the pump; an arc-shaped channel is arranged on one end face of the thrust disc, the thrust disc is fixed on the main shaft, the thrust disc is positioned at the rear end of certain bearing seats, a certain gap is arranged between the thrust disc and the end faces of certain bearing seats, the thrust disc is driven to rotate at a high speed by the high-speed rotation of the main shaft, working liquid generates a layer of axial high-pressure liquid film on the gap between the end face of the thrust disc and certain bearing seats by the aid of the arc-shaped channel, the main shaft is driven to move forwards by axial force, the thrust disc completely floats axially through the axial liquid film formed between the gaps, so that the thrust disc cannot contact with certain bearing seats, a share of axial force identical to the incoming flow direction is generated by means of buffering of the liquid film, residual axial force is easily counteracted, and the technical effects of no abrasion and no noise are achieved, so that the axial force of the whole pump is balanced, and faults and losses caused by unbalanced axial force are avoided. Meanwhile, two end surfaces of the thrust disc are plated with a layer of titanium silicon, so that the hardness, wear resistance and corrosion resistance of the thrust disc are improved.

Further, a guide vane disc is arranged on the radial outer side of the impeller body, and a guide vane is arranged on the guide vane disc. The head guide vane disk is matched with the head impeller, is positioned at the front end of the cylinder and is integrally formed with the cylinder, and a guide channel communicated with an interlayer channel on the cylinder is formed by enclosing adjacent guide vanes on the head guide vane disk and the inner wall surface of the water inlet end; the tail vane wheel is matched with the tail impeller, and a diversion channel communicated with the water outlet section is formed by enclosing adjacent diversion sheets on the tail vane wheel and the inner wall surface of the connecting section.

Further, the motor body is different from a conventional motor, the iron core of the rotor assembly and the iron core of the stator assembly are both made of ultrathin silicon steel sheets, the rotor assembly is in a surface-mounted magnetic steel structure, namely, a magnet is mounted on the surface of the rotor iron core body, and a layer of epoxy resin is coated on the surface of the magnet, so that a groove is not required to be formed in the rotor iron core body, the rotor iron core is simple in structure, and the power density of the motor is increased; the shielding sleeve of the rotor assembly adopts an ultrathin shielding sleeve, so that eddy current loss is reduced as much as possible, and the motor efficiency is improved; after the stator core is fixed with the shell, a stator shielding sleeve made of high-strength plastic is inserted, and the stator shielding sleeve is matched with a sealing piece arranged on the shell to completely isolate the stator assembly from the conveying liquid, so that a shielding effect is achieved; the stator shielding sleeve can solve the problem that a large amount of eddy current loss and heating are generated when the metal sleeve is removed, so that the motor efficiency is greatly improved; a plurality of reinforcing ribs are uniformly distributed on the outer side of the stator shielding sleeve, so that the structural strength of the stator shielding sleeve is enhanced; the inner side of the stator shielding sleeve is provided with a plurality of spiral bulges, so that the disturbance of internal fluid is increased, the flow resistance is increased, and the axial force of the whole pump is reduced.

Further, the first bearing seat and the head guide vane disc are contained in the cylinder body, the first bearing seat, the head guide vane disc and the cylinder body are integrally formed, a plurality of interlayer channels communicated with the water inlet end and liquid in the connecting section are formed in the interlayer channels, the liquid is supplied to circulate and take away heat generated outside the stator assembly, meanwhile, the number of parts is reduced, assembly and disassembly are convenient, assembly precision is improved, and the whole pump structure is more compact.

The application has the following beneficial effects:

in the application, the impeller body, the guide vane body, the bearing structure assembly, the shell and the motor part form a plurality of flow passages for conveying liquid. The bearing and the main shaft are lubricated and cooled by the conveyed liquid, and the motor is cooled, so that the expandable miniature multistage shielding pump has excellent heat dissipation performance, greatly reduces the temperature rise, and ensures the long-time reliable operation of the pump.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description, serve to explain the principles of the application.

The application may be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic cross-sectional view of a ball bearing assembly;

FIG. 2 is a schematic cross-sectional view of a hydraulic floating bearing assembly;

FIG. 3 is a schematic cross-sectional view of a slide bearing assembly;

FIG. 4 is a schematic illustration of the configuration of a hydraulic floating bearing;

FIG. 5 is a schematic diagram of the thrust plate;

FIG. 6 is a schematic diagram of a particular form of construction of an expandable micro multistage canned motor pump;

FIG. 7 is a schematic view of another particular form of construction of an expandable micro multistage canned motor pump;

FIG. 8 is a schematic view of the exterior configuration of a stator shield;

FIG. 9 is a schematic view of the outer shape of the cylinder;

FIG. 10 is another cross-sectional schematic view of a ball bearing assembly;

fig. 11 is an enlarged schematic view of the structure of fig. 2 at a.

In the figure: 1. a housing; 11. a water inlet end; 111. a water inlet; 12. a support cylinder; 121. the inner wall of the cylinder body; 122. a sandwich channel; 123. an inner cavity of the cylinder body; 124. a motor wire outlet hole; 13. a water outlet end; 131. a connection section; 132. a water outlet section; 1321. a water outlet;

2. a bearing structure assembly; 21. a hydraulic floating bearing assembly; 211. a hydraulic floating bearing body; 212. a hydraulic floating bearing seat; 2120. a left detection chamber; 2121. a connecting pipe; 2122. a right detection chamber; 2123. a right drive chamber; 2124. driving a piston; 2125. a tension spring; 2126. a left drive chamber; 2127. a push rod liquid cavity; 2128. a push rod piston; 2129. ejecting the push rod; 2130. a flow-limiting ring; 2131. an overflow trough; 2132. a stop ball; 22. a ball bearing assembly; 221. a ball bearing body; 222. ball bearing seat; 23. a sliding bearing assembly; 231. a sliding bearing body; 232. a sliding bearing seat;

3. a main shaft;

4. an impeller body; 41. a header impeller; 42. a tail impeller;

5. a motor body; 51. a rotor assembly; 52. a stator assembly; 521. a stator shield;

6. a guide vane body; 61. a header vane; 62. tail guide vanes;

7. and a thrust plate.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The application provides a scalable miniature multistage canned motor pump. As shown in fig. 1, the expandable micro multistage canned motor pump comprises a housing 1, a bearing structure assembly 2, a main shaft 3, an impeller body 4 and a motor body 5.

Specifically, as shown in fig. 1 and 2, the housing 1 is designed in three parts, including a water inlet end 11, a support cylinder 12 and a water outlet end 13, wherein the water outlet end 13 includes a connection section 131 and a water outlet section 132; the water inlet end 11 is coaxially connected to the front end of the supporting cylinder 12, the rear end of the supporting cylinder 12 is connected to the front end of the connecting section 131, the water outlet section 132 is connected to the rear end of the connecting section 131, all the parts are assembled together through mutually matched clamping grooves, and the clamping grooves are sealed and fixed through threads or welding. The water inlet 111 is arranged at the axisymmetric center of the water inlet end 11. The water outlet section 132 is provided with a water outlet 1321 at the axisymmetric center position.

In the present application, referring to fig. 4, the supporting cylinder 12 is composed of a cylinder inner wall 121, a sandwich channel 122, a cylinder inner cavity 123, and a motor wire outlet 124; the bearing structure assembly 2 is positioned in the shell 1, the main shaft 3 is supported on the bearing structure assembly 2, the impeller body 4 is fixed on the main shaft 3, the head impeller 41 is positioned between the water inlet end 11 and the supporting cylinder 12, the tail impeller 42 is positioned between the connecting section 131 and the water outlet section 132, the guide vane body 6 is divided into a head guide vane 61 and a tail guide vane 62, the head guide vane 61 is arranged on the radial outer side of the head impeller 41, and the tail guide vane 62 is arranged on the radial outer side of the tail impeller 42; the first bearing assembly is positioned behind the header impeller 41, the first bearing seat is integrally formed with the support cylinder 12 and is positioned at the front end of the support cylinder 12; the second bearing assembly and the third bearing assembly are respectively positioned at two sides of the tail impeller 42, wherein the second bearing seat is fixed between the rear end of the supporting cylinder body 12 and the connecting section 131, and the third bearing seat is integrally formed with the tail guide vane 62 and is fixed between the connecting section 131 and the water outlet section 132; the motor body 5 is located in the cylinder inner cavity 123, the motor body 5 comprises a stator assembly 52 fixed on the cylinder inner wall 121 and a rotor assembly 51 fixed on the main shaft 3, and a stator shielding sleeve 521 is coaxially arranged between the stator assembly 52 and the rotor assembly 51.

In the application, after the motor body 5 is powered on, a magnetic field is formed between the rotor assembly 51 and the stator assembly 52, the magnetic field acts on the rotor assembly 51, the rotor assembly 51 rotates at a high speed along with the magnetic field, so that the main shaft 3 coaxially fixed with the rotor assembly 51 also rotates at a high speed, and the impeller body 4 fixed on the main shaft 3 is driven to rotate at a high speed, so that the head impeller 41 draws working liquid into the water inlet 111, the head impeller 41 applies work to the working liquid, the pressure of the liquid is increased, the pressurized liquid converts part of kinetic energy of the liquid into pressure energy through the head guide vane 61 arranged on the radial outer side of the head impeller 41, the speed reduction and pressurization are realized, then the liquid mainly flows to the connecting section 131 through the interlayer channel 122 and the cylinder cavity 123, the tail impeller 42 in the connecting section 131 continues to apply work to the working liquid, the working liquid flows out through the tail guide vane 62 arranged on the radial outer side of the tail impeller 42 after the work liquid is pressurized again, and the work of the head guide vane 61 is repeated, and the working liquid flows out through the water outlet 1321, and the specific flow track is shown by an arrow in fig. 1.

In the application, a plurality of through holes are processed on the ring surface of a bearing seat, the through holes on a first bearing seat are connected with a water inlet 111 and a cylinder inner cavity 123, and working liquid leaks from the back of a header impeller 41 and flows into the cylinder inner cavity 123 through the through holes and the first bearing; the working fluid flowing into the front end of the inner cavity 123 of the cylinder body automatically lubricates the first bearing, so that the abrasion of the first bearing is reduced; working fluid flowing into the front end of the inner cavity 123 of the cylinder flows into the rear end of the inner cavity 123 of the cylinder through a gap between the stator shielding sleeve 521 and the rotor assembly 51 under the action of internal pressure, and a plurality of spiral bulges are arranged on the inner side of the stator shielding sleeve 521, so that disturbance of the working fluid is increased, flow resistance of the working fluid is increased, pressure in the rear end of the inner cavity 123 of the cylinder is reduced, and axial force of the whole pump is reduced. The working fluid flowing into the rear end of the inner cavity 123 of the cylinder lubricates the second bearing and then flows into the connecting section 131 through the through hole on the second bearing seat and the second bearing and then is converged into the main flow; the working fluid after having collected into the main flow repeats the action of the leading impeller 41 again at the trailing impeller 42, and flows into the water outlet section 132 through the through hole in the third bearing and the third bearing.

In the present application, as shown in fig. 2, the bearing structure assembly 2 employs a hydraulic floating bearing assembly 21, and the hydraulic floating bearing assembly 21 includes a hydraulic floating bearing housing 212 fixed to the housing 1 and a hydraulic floating bearing body 211 fixed to the main shaft 3. As shown in fig. 4, the mating surfaces of the hydraulic floating bearing body 211 and the hydraulic floating bearing seat 212 are provided with an "eight" shaped channel, when the spindle 3 rotates at a high speed, the working fluid is extruded toward the center along the "eight" shaped channel, and a radial liquid film is formed by a pressure difference generated by the compression of the fluid in the channel, so that the spindle 3 can be suspended in the working fluid in the radial direction. The liquid film has high pressure and thus good bearing capacity, and the higher the rotating speed of the rotor is, the stronger the rigidity of the bearing is, and meanwhile, the liquid film can enable the hydraulic floating bearing body 211 to achieve the effect of self lubrication. Thus, the whole pump does not need lubricating liquid, and the pollution of the lubricating liquid to working liquid is avoided; moreover, the whole pump adopts a hydrodynamic pressure lubrication mode, compared with solid lubrication, almost no friction and heating are realized, so that the technical effects of no abrasion and no noise are achieved, the whole pump has smaller heating loss and longer service life, and the requirement on the whole pump efficiency can be met by higher rotating speed.

In the present application, as shown in fig. 1, the bearing structure assembly 2 employs a ball bearing assembly 22 including a ball bearing body 221 fixed to the housing 1 and a ball bearing housing 222 supporting the spindle 3. The ball bearing seat 222 is a miniature precise ceramic high-speed angular contact bearing, has the characteristic of self-lubricating a conveying medium, does not need to be filled with lubricating grease in the middle, avoids the condition that the lubricating grease of a common ball bearing fails and pollutes the conveying medium, and the wear resistance of ceramic materials greatly improves the service life and reliability of a bearing system, and is suitable for occasions with high rotating speed, intermittent operation and more start and stop times. Meanwhile, since the ball bearing housing 222 is in interference with the ball bearing body 221 or with the spindle 3, the generated interference force can better resist the generated axial force.

In the present application, as shown in fig. 3, the bearing structure assembly 2 employs a slide bearing assembly 23 including a slide bearing body 231 fixed to the housing 1 and a slide bearing block 232 supporting the spindle 3. The inner wall of the sliding bearing seat 232 is arranged on the sliding bearing body 231 in an interference manner, a plurality of spiral channels are formed in the inner wall of the sliding bearing seat 232, the main shaft is supported on the inner wall of the sliding bearing seat 232, and working fluid flows into the spiral channels to lubricate the sliding bearing seat 232, so that friction is reduced; the sliding bearing block 232 is made of special graphite or silicon carbide material and has self-lubricating property.

In combination with the above, when the bearing structure assembly 2 adopts the hydraulic floating bearing assembly 21 or the sliding bearing assembly 23, the rotation of the header impeller 41 can make the working fluid in the water inlet 111 flow, but due to the rotation of the header impeller 41 in the liquid medium, the header impeller 41 is forced to drive the spindle 3 to move towards the water inlet 111, and in order to solve the damage of the axial force to the pump, the thrust disc 7 is additionally arranged behind the second bearing assembly, as shown in fig. 2 or 3; an arc-shaped channel is arranged on one end face of the thrust disc 7, as shown in fig. 5, the thrust disc 7 is fixed on the main shaft 3, the thrust disc 7 is positioned at the rear end of the second bearing seat, a certain gap is arranged between the thrust disc 7 and the end face of the second bearing seat, the thrust disc 7 is driven to rotate at a high speed by the high-speed rotation of the main shaft 3, working liquid generates a layer of axial high-pressure liquid film on the gap between the end face of the thrust disc 7 and the second bearing seat by the aid of the arc-shaped channel, the main shaft 3 is driven to move leftwards by axial force, the thrust disc 7 completely axially floats through the axial liquid film formed between the gaps, so that the thrust disc 7 cannot be contacted with the second bearing seat, an axial force identical to the incoming flow direction is generated by virtue of buffering of the liquid film, the residual axial force is easily counteracted, the technical effects of no abrasion and no noise are achieved, the axial force of the whole pump is balanced, and faults and losses caused by unbalanced axial force are avoided. Meanwhile, two end surfaces of the thrust disc 7 are plated with a layer of titanium silicon, so that the hardness, wear resistance and corrosion resistance of the thrust disc 7 are improved.

In order to accelerate the rotation of the thrust disc 7 to offset the axial force of the head impeller 41 to drive the main shaft 3 to move left, as is obvious from fig. 2 and 11, a left detection cavity 2120 and a right detection cavity 2122 are formed on the inner side of the hydraulic floating bearing seat 212 and are positioned on the outer side of the hydraulic floating bearing body 211, the left detection cavity 2120 and the right detection cavity 2122 are symmetrically arranged, the left detection cavity 2120 is communicated with a left driving cavity 2126 formed in the hydraulic floating bearing seat 212 through a connecting pipe 2121, the right detection cavity 2122 is communicated with a right driving cavity 2123 formed in the hydraulic floating bearing seat 212 through a connecting pipe 2121, a driving piston 2124 is arranged between the right driving cavity 2123 and the left driving cavity 2126, so that when the pressure of working fluid between the right driving cavity 2123 and the left driving cavity 2126 changes, the driving piston 2124 can move left and right, one end of the driving piston 2124 is fixedly connected with a flow limiting ring 2130, one end of the flow-limiting ring 2130 is annular and is positioned between the hydraulic floating bearing seat 212 and the thrust disc 7, so that when the flow-limiting ring 2130 moves, the flow area of working fluid between the thrust disc 7 and the hydraulic floating bearing seat 212 can be changed, when the axial force of the hydraulic floating bearing body 211 and the thrust disc 7 on the main shaft 3 moves left and right, for example, when the axial force moves the main shaft 3 left, the splayed channel on the left side of the hydraulic floating bearing body 211 is relatively far away from the inner side of the hydraulic floating bearing seat 212, so that the amount of the working fluid conveyed by the splayed channel to the left detection cavity 2120 is relatively reduced, the amount of the working fluid flowing into the right detection cavity 2122 is forced to be increased due to the increase of the flow areas of the right detection cavity 2122 and the splayed channel, the pressure of the working fluid in the left driving cavity 2126 is relatively smaller than the pressure of the working fluid in the right driving cavity 2123, the flow-limiting ring 2130 tends to move to the right at this time, so that the flow area between the hydraulic floating bearing seat 212 and the thrust disc 7 is reduced, and the strength of a high-pressure liquid film between the thrust disc 7 and the hydraulic floating bearing seat 212 is increased, so that the strength of the thrust disc 7 pulling the main shaft 3 to the right is increased, and similarly, when the main shaft 3 moves to the right, the flow-limiting ring 2130 moves to the left, the flow quantity of working liquid is increased, and the thrust disc 7 moves to the left; in a normal working state, the working fluid conveyed in the left detection cavity 2120 and the right detection cavity 2122 by the splayed grooves on the outer side of the hydraulic floating bearing body 211 is the same, and the driving piston 2124 is kept at the middle position, so that the axial force of the main shaft 3 can be counteracted when the thrust disc 7 rotates.

If the movement amplitude of the thrust disc 7 is too large, the outside personnel is not easy to perceive, so that a push rod liquid cavity 2127 is formed in the flow limiting ring 2130, the push rod piston 2128 is movably installed in the push rod liquid cavity 2127, one end of the push rod piston 2128 is fixedly connected with an ejection push rod 2129 positioned at one side of the end part of the flow limiting ring 2130, the end part of the ejection push rod 2129 is provided with a poking plate, when the poking plate is intermittently contacted with an arc-shaped groove on the end surface of the thrust disc 7, the poking plate can generate intermittent metal friction sound, as is obvious in combination with fig. 11, a tension spring 2125 for connecting the push rod piston 2128 and the driving piston 2124 is arranged in the push rod liquid cavity 2127, so that the push rod piston 2128 always has a trend of moving towards the driving piston 2124 through the elastic pulling of the tension spring 2125, a limited ball 2132 is movably arranged in the push rod liquid cavity 2127, the inner side of the hydraulic floating bearing 212 is provided with an arc-shaped groove corresponding to the limited ball 2132, therefore, when the driving piston 2124 moves, the limiting ball 2132 limits a certain starting force, when the thrust plate 7 is prevented from swinging in a small amplitude, the flow limiting ring 2130 frequently moves, the overflow groove 2131 is formed in the inner side of the flow limiting ring 2130, when the push rod piston 2128 moves to the overflow groove 2131, part of working fluid in the push rod fluid cavity 2127 can flow outwards from the small part of the overflow groove 2131, meanwhile, the liquid medium in the push rod fluid cavity 2127 can be normally discharged, in the practical use process, when the main shaft 3 drives the hydraulic floating bearing body 211 to deviate to the limit to the right, the driving piston 2124 moves to the leftmost position of the right driving cavity 2123, at this time, the right detecting cavity 2122 is communicated with the push rod fluid cavity 2127 through the connecting pipe 2121, and the working medium in the right detecting cavity 2122 pushes the push rod piston 2128 to move to the right side until the end part of the push rod 2129 contacts the thrust plate 7, and sounds are released; in the same way, the processing method comprises the steps of, when the main shaft 3 drives the hydraulic floating bearing body 211 to shift to the limit left, the end part of the ejection push rod 2129 is already contacted with the thrust disc 7 when the motion of the driving piston 2124 does not reach the connecting pipe 2121, so that the stirring sheets at the end part of the ejection push rod 2129 can make sounds after the main shaft 3 moves to the limit to the two sides in the axial direction finally; in normal use, the drive piston 2124 is in the middle position, at this time, the tension spring 2125 is under its own elastic tension to pull the push rod piston 2128 towards the drive piston 2124, the contact in the push rod liquid chamber 2127 is discharged outwards from the drive piston 2124, and finally, when the push rod piston 2128 passes over the overflow groove 2131, working liquid in the push rod liquid chamber 2127 is extruded, so that the stopper ball 2132 is extruded into the arc groove of the hydraulic floating bearing seat 212 under the increase of liquid pressure.

In the application, as shown in fig. 6, the tail impeller 42, the tail guide vane 62 and the connecting section 131 are not required to form the miniature single-stage canned motor pump.

In the application, as shown in fig. 7, a plurality of tail impellers 42, tail guide vanes 62 and connecting sections 131 can be further arranged, the connecting sections 131 are connected with each other, and the last connecting section 131 is fixedly connected with the water outlet section 132 to form a miniature multi-stage shielding pump.

In the application, the motor body 5 is a permanent magnet synchronous motor and is made into a shielding structure. The rotor assembly 51 is fixed through a shaft shoulder on the main shaft 3, the rotor assembly 51 is tightly matched with the main shaft 3, the rotor assembly 51 is completely covered through a rotor shielding sleeve, and the rotor shielding sleeve is fixed on the main shaft 3 through welding; the stator assembly 52 is positioned on the radial outer side of the rotor assembly 51 and fixed on the inner wall 121 of the cylinder, and after the stator assembly 52 is tightly matched with the inner wall 121 of the cylinder, motor wiring is led out from the motor wire outlet hole 124; a stator shielding sleeve 521 is arranged between the rotor assembly 51 and the stator assembly 52, and the stator shielding sleeve 521 is matched with a sealing element arranged in the shell 1 to completely isolate the stator assembly 52 from working liquid, thereby achieving a shielding effect; the outer side of the stator shielding sleeve 521 is uniformly provided with a plurality of reinforcing ribs for enhancing the structural strength of the stator shielding sleeve 521, and the inner side of the stator shielding sleeve 521 is provided with a plurality of spiral bulges, as shown in fig. 8, so that the disturbance of internal fluid is increased, the flow resistance is increased, and the axial force of the whole pump is reduced.

In the application, the motor body 5 is a high-speed motor, and the high-speed running of the motor body 5 drives the impeller body 4 to carry out high-speed centrifugal supercharging. The speed of the high-speed impeller is generally 3-5 times higher than that of a conventional centrifugal pump, and the higher the rotating speed of the impeller body 4 is, the smaller the impeller diameter required for reaching the same flow lift is, so that the volume of the expandable miniature multistage shielding pump is greatly reduced.

In the present application, as shown in fig. 9, the end surface of the support cylinder 12 is formed with a plurality of arc grooves, and a sandwich passage 122 is formed throughout the support cylinder 12. As shown in fig. 10, a solid portion of the support cylinder 12, which is not provided with an arc-shaped groove, is provided with a motor outlet hole 124 communicating the cylinder inner cavity 123 with the outside of the housing 1, so that the motor wiring is completely isolated from the liquid.

In the application, the working liquid fills each gap, the rotor assembly 51 and the stator assembly 52 are completely covered by the working liquid, and the flowing liquid well takes away the heat generated by the motor body 5, so that the motor is not required to be damaged due to over-high temperature rise.

Claims (10)

1. The utility model provides an expandable miniature multistage canned motor pump, includes casing (1), main shaft (3), impeller body (4) and motor body (5), its characterized in that:

the main shaft (3) is arranged in the shell (1), and the impeller body (4) is fixed on the main shaft (3);

the motor body (5) is arranged in the shell (1), the motor body (5) comprises a rotor assembly (51) and a stator assembly (52), the rotor assembly (51) is fixed on the main shaft (3), and the stator assembly (52) is fixed on the inner wall of the shell (1);

the casing (1), the main shaft (3), the impeller body (4) and the motor body (5) jointly form a plurality of channels for medium circulation, an interlayer channel (122) is formed in the casing (1) located on the outer side of the stator assembly (52), at least one channel flows through the interlayer channel (122), and at least one channel flows through the gap between the rotor assembly (51) and the stator assembly (52).

2. The expandable micro multistage canned motor pump according to claim 1, wherein the housing (1) comprises a water inlet end (11), a supporting cylinder (12) and a water outlet end (13), a sandwich channel (122) for liquid to flow is formed in the cylinder wall of the supporting cylinder (12), and a water inlet (111) and a water outlet (1321) are respectively formed in the water inlet end (11) and the water outlet end (13);

the impeller body (4) comprises a head impeller (41) positioned at the front end of the main shaft (3) and a plurality of tail impellers (42) positioned at the rear end of the main shaft (3), the water outlet end (13) comprises a connecting section (131) matched with the tail impellers (42) and a water outlet section (132) provided with a water outlet discharge port (1321), and the connecting section (131) and the water outlet section (132) are both provided with necking structures for converging fluid;

the connecting section (131) and the water outlet section (132) are provided with mutually matched clamping grooves, the clamping grooves can be sealed and fixed through threads or welding, and the connecting section (131) can be continuously overlapped through the mutually matched clamping grooves;

a bearing structure assembly (2) is arranged in the shell (1), so that the spindle (3) can rotate and can bear axial force.

3. The expandable micro multistage canned motor pump according to claim 2, wherein the bearing structure assembly (2) is composed of a plurality of hydraulic floating bearing assemblies (21), the hydraulic floating bearing assemblies (21) comprise a hydraulic floating bearing body (211) arranged on the main shaft (3) and a hydraulic floating bearing seat (212) arranged on the shell (1), and an eight-shaped groove is arranged on the matching surface of the hydraulic floating bearing body (211) and the hydraulic floating bearing seat (212) and used for generating a high-pressure liquid film when rotating at a high speed and supporting the main shaft (3) to float.

4. The expandable mini multistage canned motor pump according to claim 2, characterized in that the bearing structure assembly (2) is constituted by a number of ball bearing assemblies (22), the ball bearing assemblies (22) are constituted by a ball bearing body (221) and a ball bearing housing (222), the ball bearing housing (222) is fixed on the housing (1), the ball bearing body (221) is fixed on the ball bearing housing (222) with an outer ring, and an inner ring is fixed on the main shaft (3), the ball bearing body (221) having self-lubricating properties.

5. The expandable micro multistage canned motor pump according to claim 2, wherein the bearing structure assembly (2) is composed of a plurality of sliding bearing assemblies (23), the sliding bearing assemblies (23) comprise sliding bearing bodies (231) and sliding bearing bases (232), the sliding bearing bases (232) are fixed on the shell, a plurality of spiral grooves are formed in the inner walls of the sliding bearing bodies (231) and matched with the main shaft (3), and the sliding bearing bodies (231) are made of special graphite or silicon carbide materials and have self-lubricating characteristics.

6. The expandable mini multistage canned motor pump according to any one of claims 3-5, wherein a plurality of thrust discs (7) are arranged in the housing (1), the thrust discs (7) are fixed on the main shaft (3), a plurality of arc-shaped channels are arranged on the working end face, and the thrust discs (7) are positioned at the rear end of the bearing seat.

7. The expandable mini-multistage canned motor pump according to claim 2, characterized in that the stator assembly (52) is isolated from the inside of the casing (1) by a cylindrical stator casing (521), the stator casing (521) being made of PPS or PEEK plus glass fibre material.

8. The expandable mini-multistage canned motor pump according to claim 7, wherein the stator casing (521) is provided on its inner surface with protruding or recessed ridges, which are helical.

9. The expandable micro multistage canned motor pump according to claim 6, wherein a left detection cavity (2120) and a right detection cavity (2122) located outside the hydraulic floating bearing body (211) are formed inside the hydraulic floating bearing seat (212), the left detection cavity (2120) is communicated with a left driving cavity (2126) formed inside the hydraulic floating bearing seat (212) through a connecting pipe (2121), the right detection cavity (2122) is communicated with a right driving cavity (2123) formed inside the hydraulic floating bearing seat (212) through the connecting pipe (2121), a driving piston (2124) is arranged between the right driving cavity (2123) and the left driving cavity (2126), and a flow limiting ring (2130) for controlling a working fluid flow area between the thrust disc (7) and the bearing structure assembly (2) is fixed at one end of the driving piston (2124).

10. The expandable micro multistage canned motor pump according to claim 9, wherein a push rod liquid chamber (2127) provided with a push rod piston (2128) is formed in the flow limiting ring (2130), one end of the push rod piston (2128) is fixedly connected with an ejection push rod (2129) positioned at one side of the end of the flow limiting ring (2130), a poking plate is arranged at the end of the ejection push rod 2129, and when the poking plate is intermittently contacted with an arc-shaped channel at the end surface of the thrust plate (7), the poking plate can generate intermittent metal friction sound;

a tension spring (2125) for connecting the push rod piston (2128) and the driving piston (2124) is arranged in the push rod liquid cavity (2127), a limited motion ball (2132) is movably arranged in the push rod liquid cavity (2127), and an arc groove corresponding to the limited motion ball (2132) is formed in the inner side of the hydraulic floating bearing seat (212);

an overflow groove (2131) is formed in the inner side of the flow limiting ring (2130).