Expandable micro multi-stage canned pump

Abstract

The application relates to the technical field of canned pumps, in particular to an extensible micro multi-stage canned pump which comprises a supporting cylinder, a sandwich channel for liquid flow is arranged on the cylinder wall of the supporting cylinder; a stator is coaxially fixed on the wall surface of the inner cavity of the supporting cylinder, a main shaft is coaxially rotatably arranged in the inner cavity of the supporting cylinder, a rotor matched with the stator is arranged on the main shaft, and a flow gap is formed between the stator and the rotor; the main shaft is fixed on an inner bearing of a shell, and a plurality of impellers for driving liquid work are arranged on the main shaft; the components of the extensible micro multi-stage canned pump jointly form a plurality of flow channels, a plurality of surfaces of a motor are wrapped by the flow channels, the heat dissipation performance is greatly improved, and the extensible micro multi-stage canned pump can stack a plurality of impellers according to requirements to reach the required performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shielded pumps, in particular to an extensible micro multi-stage shielded pump. BACKGROUND

[0002] With the rapid development of modern electronic technology, special electronic equipment in the fields of 5G base stations, radar thermal control systems, offshore ships, aircraft platforms, etc. are increasingly high-integrated and large-power, and the power of electronic equipment is increasingly large, and its heat loss also increases, and traditional air cooling has been difficult to meet the cooling demand at the present stage.

[0003] Compared with traditional air cooling, liquid cooling has stronger cooling capacity, and is an inevitable trend of high-end electronic equipment cooling. As the core component for driving the circulation of liquid working medium, the pump is equivalent to the heart of human blood circulation, but the size of the pump becomes a major obstacle for its application in these fields.

[0004] The bearing system of a common micro pump is in communication with the liquid chamber, so that the lubricating oil in the bearing system is diluted by the working liquid, loses the lubricating ability, and the shaft and the bearing are directly rubbed, greatly deteriorating the service life and noise of the pump. Most of the current solutions use dynamic sealing methods to separate the bearing from the fluid using packing or a sealing ring, but the sealing ability of this method is poor, and the friction between the shaft and the sealing element will reduce the driving force of the motor to the impeller output, greatly reducing the performance of the micro pump.

[0005] The ball bearing used in the prior art micro pump has the following shortcomings: first, the lubricating grease of the ball bearing is easily washed away when it is immersed in water for long-term operation in the micro pump, resulting in failure; second, due to wear, the service life of the ball bearing is relatively low; third, due to wear, the noise is relatively large.

[0006] At the same time, the existing micro shielded pump often cannot meet the performance of some high-lift working conditions due to the pursuit of small size, and the multi-stage shielded pump that meets the high-lift is too large in size.

[0007] Therefore, we propose an extensible micro multi-stage shielded pump to solve the above problems. SUMMARY

[0008] The application discloses an extensible micro multi-stage shielding pump, which comprises a shell, a bearing structure assembly, a main shaft, an impeller body and a motor body. The shell is provided with a water inlet for liquid inflow and a water outlet for liquid outflow. The bearing structure assembly comprises a bearing and a bearing seat fixed on the shell. The main shaft is supported on the bearing. The impeller body comprises a head impeller fixed on the main shaft near the water inlet end and a plurality of tail impellers fixed on the main shaft near the water outlet end. The motor body comprises a rotor assembly fixed on the main shaft and a stator assembly fixed in the shell.

[0009] Further, the shell comprises a water inlet end, a supporting cylinder and a water outlet end. The water inlet end is coaxially connected with the front end of the supporting cylinder, and 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 the water outlet. The connecting section and the water outlet section are coaxially connected. The water inlet end, the supporting cylinder, the connecting section and the water outlet section are all provided with matched clamping grooves. The matched clamping grooves can be fixed by threads or welding. The connecting section can be continuously stacked through the matched clamping grooves.

[0010] Further, the water inlet end is provided with a water inlet for fluid inflow and communication with the head impeller. The cylinder wall of the supporting cylinder is provided with a interlayer channel for liquid flow. The connecting section of the water outlet end is provided with a flow channel communicated with the interlayer channel and the tail impeller. The water outlet section of the water outlet end is provided with a water outlet communicated with the tail impeller and for liquid outflow. The connecting section and the water outlet section are both provided with a necking structure for fluid convergence.

[0011] 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. The hydraulic floating bearing seat is provided with a through hole for liquid flow. The hydraulic floating bearing body is provided with an "eight" shaped groove on the matched surface of the hydraulic floating bearing seat. The "eight" shaped groove is used for generating high pressure liquid film at high speed rotation, supporting the main shaft in suspension, lubricating and cooling the main shaft, and increasing the rigidity of the bearing with the increase of the rotating speed of the rotor.

[0012] Further, 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 supporting the main shaft, the ball bearing seat is provided with a through hole for the flow of liquid, the ball bearing body is a micro-precision ceramic high-speed angular contact bearing, which can adapt to high-speed rotation, intermittent operation and a large number of start-stop occasions; at the same time, since the ball bearing body is in interference fit with the ball bearing seat and the main shaft, the interference force generated can better resist the axial force generated. The ball bearing body has a self-lubricating property of transporting medium, and does not need to be filled with lubricating grease in the middle, avoiding the failure and pollution of the lubricating grease of general metal ball bearings to the transported medium, and the wear resistance of the ceramic material greatly improves the service life and reliability of the bearing system.

[0013] 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 supporting the main shaft, the sliding bearing seat is provided with a through hole for the flow of liquid, the sliding bearing outer wall is interference fitted on the sliding bearing seat, the sliding bearing inner wall is provided with a plurality of spiral grooves, the main shaft is supported on the sliding bearing inner wall, and liquid flows into the spiral grooves to lubricate the sliding bearing and reduce friction; the sliding bearing body is made of special graphite or silicon carbide material and has a self-lubricating property.

[0014] Further, when the bearing structure assembly adopts a hydraulic floating bearing assembly or a sliding bearing assembly, in order to solve the damage of the axial force to the pump, a thrust disc is installed behind some bearing assemblies; one end surface of the thrust disc is provided with an arc-shaped groove, the thrust disc is fixed on the main shaft, the thrust disc is located behind the end of some bearing seats, and a certain gap is provided between the end surface of the thrust disc and the end surface of some bearing seats, the high-speed rotation of the main shaft drives the high-speed rotation of the thrust disc, the high-speed rotation of the thrust disc utilizes the arc-shaped groove to make a layer of high-pressure liquid film on the gap between the end surface of the thrust disc and some bearing seats, the axial force makes the main shaft and the thrust disc move forward, the axial liquid film formed between the gap makes the thrust disc completely axially float, so that the thrust disc cannot contact some bearing seats, and a certain axial force in the same direction as the flow direction is generated by the buffer of the liquid film, which easily offsets the remaining axial force, achieving the technical effects of no wear and no noise, so that the axial force of the whole pump is balanced, avoiding the failure and loss caused by the unbalanced axial force. Meanwhile, the two end surfaces of the thrust disc are plated with a layer of titanium silicon, improving the hardness, wear resistance and corrosion resistance of the thrust disc.

[0015] Further, the impeller body is radially arranged with a guide vane disc, and the guide vane disc is provided with guide vanes. The first head impeller is matched with the first head guide vane disc, the first head guide vane disc is located at the front end of the cylinder body and is integrally formed with the cylinder body, and the adjacent guide vanes on the first head guide vane disc and the inner wall surface of the water inlet end are enclosed to form a guide flow channel which is communicated with the interlayer channel on the cylinder body. The tail impeller is matched with the tail guide vane disc, and the adjacent guide vanes on the tail guide vane disc and the inner wall surface of the connecting section are enclosed to form a guide flow channel which is communicated with the water outlet section.

[0016] Further, the motor body is different from the conventional motor, the cores of the rotor assembly and the stator assembly are both made of ultra-thin silicon steel sheets, the rotor assembly adopts a surface-mounted magnetic steel structure, that is, a magnet is attached to the surface of the rotor core body, and a layer of epoxy resin is applied to the surface, which does not need to be slotted in the rotor core body, so that the structure of the rotor core is simple and the power density of the motor is increased; the shielding sleeve of the rotor assembly adopts an ultra-thin shielding sleeve to reduce eddy current loss as much as possible to improve the efficiency of the motor; after the stator core is fixed with the shell, a stator shielding sleeve made of high-strength plastic is inserted, the stator shielding sleeve cooperates with the sealing element arranged on the shell to completely isolate the stator assembly from the conveying liquid, thereby achieving a shielding effect; the stator shielding sleeve can solve the problem of a large amount of eddy current loss and heating caused by the metal sleeve, thereby greatly improving the efficiency of the motor; and a plurality of reinforcing ribs are uniformly distributed on the outer side of the stator shielding sleeve to enhance the structural strength of the stator shielding sleeve; a plurality of spiral protrusions are arranged on the inner side of the stator shielding sleeve to increase the disturbance of the internal fluid, increase the flow resistance, and reduce the axial force of the whole pump.

[0017] Further, the first bearing seat and the first head guide vane disc are contained in the cylinder body and are integrally formed, and a plurality of interlayer channels for communicating the liquid in the water inlet end and the connecting section are arranged thereon to provide the liquid flow and carry away the heat generated on the outer side of the stator assembly, and the number of parts is reduced, the assembly and disassembly are facilitated, the assembly accuracy is improved, and the structure of the whole pump is more compact.

[0018] The present application has the following beneficial effects:

[0019] In the present application, the impeller body, the guide vane body, the bearing structure assembly, the shell and the motor part jointly constitute a plurality of flow channels for conveying liquid. The liquid used for lubrication and cooling of the bearing and the main shaft, and heat dissipation of the motor, so that the expandable micro multi-stage shielding pump has excellent heat dissipation performance, the temperature rise is greatly reduced, and the long-term reliable operation of the pump is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present application and serve to explain the principles of the present application together with the specification.

[0021] The present application can be more clearly understood and appreciated from the following detailed description, with reference to the accompanying drawings.

[0022] Figure 1 Fig. 1 is a sectional view of a ball bearing assembly;

[0023] Figure 2 Fig. 2 is a sectional view of a hydraulic floating bearing assembly;

[0024] Figure 3 Fig. 3 is a sectional view of a sliding bearing assembly;

[0025] Figure 4 Fig. 4 is a schematic view of a hydraulic floating bearing;

[0026] Figure 5 Fig. 5 is a schematic view of a thrust disc;

[0027] Figure 6 Fig. 6 is a schematic view of a special form of an expandable miniature multi-stage canned motor pump;

[0028] Figure 7 Fig. 7 is a schematic view of another special form of an expandable miniature multi-stage canned motor pump;

[0029] Figure 8 Fig. 8 is a schematic view of a stator can;

[0030] Figure 9 Fig. 9 is a schematic view of a cylinder;

[0031] Figure 10 Fig. 10 is another sectional view of a ball bearing assembly;

[0032] Figure 11 Fig. 11 is a schematic view of Figure 2 Fig. 12 is an enlarged view of the structure at A in Fig. 11.

[0033] In the figure: 1, housing; 11, water inlet end; 111, water inlet; 12, support cylinder; 121, cylinder inner wall; 122, interlayer passage; 123, cylinder inner cavity; 124, motor outlet hole; 13, water outlet end; 131, connecting section; 132, water outlet section; 1321, water outlet;

[0034] 2, bearing structure assembly; 21, hydraulic floating bearing assembly; 211, hydraulic floating bearing body; 212, hydraulic floating bearing seat; 2120, left detection cavity; 2121, connecting pipe; 2122, right detection cavity; 2123, right driving cavity; 2124, driving piston; 2125, tension spring; 2126, left driving cavity; 2127, push rod liquid cavity; 2128, push rod piston; 2129, push rod ejector; 2130, flow limiting ring; 2131, overflow groove; 2132, limiting ball; 22, ball bearing assembly; 221, ball bearing body; 222, ball bearing seat; 23, sliding bearing assembly; 231, sliding bearing body; 232, sliding bearing seat;

[0035] 3. Spindle;

[0036] 4. Impeller body; 41. Head impeller; 42. Tail impeller;

[0037] 5. Motor body; 51. Rotor assembly; 52. Stator assembly; 521. Stator shield;

[0038] 6. Guide vane body; 61. Head guide vane; 62. Tail guide vane;

[0039] 7. Thrust plate. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0041] The present invention provides an expandable micro multi-stage canned motor pump. Figure 1 As shown, the expandable micro multi-stage shielded pump includes a housing 1, a bearing structure assembly 2, a main shaft 3, an impeller body 4 and a motor body 5.

[0042] Specifically, if Figure 1 and Figure 2 As shown, the housing 1 is designed into three parts, including an inlet end 11, a support cylinder 12, and a water outlet end 13, wherein the water outlet end 13 includes a connecting section 131 and a water outlet section 132; the inlet end 11 is coaxially connected to the front end of the support cylinder 12, the rear end of the support cylinder 12 is connected to the front end of the connecting section 131, and the water outlet section 132 is connected to the rear end of the connecting section 131. The various parts are assembled together by a combination of mutually cooperating slots, and the slots are sealed and fixed by threads or welding. A water inlet 111 is provided at the axially symmetrical center of the water inlet end 11. A water outlet 1321 is provided at the axially symmetrical center of the water outlet section 132.

[0043] In the present invention, combined with Figure 4It can be known that the support cylinder 12 is composed of the cylinder inner wall 121, the sandwich channel 122, the cylinder inner cavity 123 and the motor wire hole 124; the bearing structure assembly 2 is located inside 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 located between the water inlet end 11 and the support cylinder 12, the tail impeller 42 is located between the connecting section 131 and the water outlet section 132, the guide vane body 6 is divided into the head guide vane 61 and the 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 located behind the head impeller 41, the first bearing seat is integrally formed with the support cylinder 12 and located at the front end of the support cylinder 12; the second bearing seat and the third bearing seat are respectively located on both sides of the tail impeller 42, wherein the second bearing seat is fixed between the rear end of the support cylinder 12 and the connecting section 131, and the third bearing seat is integrally formed with the tail guide vane 62 and 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 the stator assembly 52 fixed on the cylinder inner wall 121 and the rotor assembly 51 fixed on the main shaft 3, and the stator shield sleeve 521 is coaxially arranged between the stator assembly 52 and the rotor assembly 51.

[0044] In the application, the motor body 5 forms a magnetic field between the rotor assembly 51 and the stator assembly 52 after being connected to the power supply, the magnetic field acts on the rotor assembly 51, the rotor assembly 51 rotates at high speed with the magnetic field, the main shaft 3 fixed coaxially with the rotor assembly 51 also rotates at high speed, and then drives the impeller body 4 fixed on the main shaft 3 to rotate at high speed, so that the head impeller 41 rolls the working liquid into the water inlet 111, the head impeller 41 does work on the working liquid, increases the pressure of the liquid, the liquid after being pressurized passes through the head guide vane 61 arranged on the radial outer side of the head impeller 41, the head guide vane 61 converts part of the kinetic energy of the liquid into pressure energy, realizes speed reduction and pressure increase, and then the liquid mainly flows to the connecting section 131 through the sandwich channel 122 and the cylinder inner cavity 123, the tail impeller 42 in the connecting section 131 continues to do work on the working liquid, pressurizes the working liquid again, and then passes through the tail guide vane 62 arranged on the radial outer side of the tail impeller 42, after repeating the action of the head guide vane 61, the working liquid flows out through the water outlet 1321, and the specific flow trajectory is shown by arrows. Figure 1

[0045] ​In the application, the torus of the bearing seat is processed with several through holes, the through holes on the first bearing seat connect the water inlet 111 and the inner cavity 123 of the cylinder, the working liquid leaked from the back of the first impeller 41 flows into the inner cavity 123 of the cylinder through the through holes and the first bearing, the working liquid flowing into the front end of the inner cavity 123 of the cylinder can automatically lubricate the first bearing to reduce the wear of the first bearing, the working liquid 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 the gap between the stator shield sleeve 521 and the rotor assembly 51 under the action of the internal pressure, the inner side of the stator shield sleeve 521 is provided with several spiral protrusions, which increases the disturbance of the working fluid, increases the flow resistance, reduces the pressure in the rear end of the inner cavity 123 of the cylinder, and thus reduces the axial force of the whole pump, the working liquid 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 holes on the second bearing seat and the second bearing and then flows into the main flow, the working fluid flowing into the main flow repeats the action at the first impeller 41 at the tail impeller 42, and then flows into the water outlet section 132 through the through holes on the third bearing seat and the third bearing.

[0046] In the application, as shown in the figure, Figure 2 The bearing structure assembly 2 adopts a hydraulic floating bearing assembly 21, which comprises a hydraulic floating bearing seat 212 fixed on the shell 1 and a hydraulic floating bearing body 211 fixed on the main shaft 3. Figure 4 As shown in the figure, the matching surface of the hydraulic floating bearing body 211 and the hydraulic floating bearing seat 212 is provided with an "eight" shaped groove, when the main shaft 3 rotates at high speed, the working liquid will be extruded to the center along the "eight" shaped groove, the pressure difference caused by the compression of the liquid in the groove forms a layer of radial liquid film, so that the main shaft 3 can be suspended in the working liquid in the radial direction. The liquid film has high pressure and thus has good carrying capacity, and the higher the speed of the rotor, the stronger the stiffness of the bearing, at the same time, the liquid film can achieve the effect of self-lubrication of the hydraulic floating bearing body 211. In this way, the whole pump does not need lubricating liquid, avoiding the pollution of the lubricating liquid to the working liquid, and the whole pump adopts liquid dynamic pressure lubrication, which has almost no friction and heating compared with solid lubrication, so as to achieve the technical effects of no wear and no noise, which makes the whole pump have smaller heat loss and longer operation life, and can reach higher speed to meet the requirement of the efficiency of the whole pump.

[0047] In the application, as shown in the figure, Figure 1As shown, the bearing structure assembly 2 adopts a ball bearing assembly 22, which includes a ball bearing body 221 fixed on the housing 1 and a ball bearing seat 222 supporting the main shaft 3. The ball bearing seat 222 is a micro-precision ceramic high-speed angular contact bearing, has a self-lubricating property, and does not need to be filled with lubricating grease in the middle, thereby avoiding the failure of the lubricating grease of the general ball bearing and the pollution of the conveying medium. In addition, the wear resistance of the ceramic material greatly improves the service life and reliability of the bearing system, and the bearing system can be adapted to high-speed rotation, intermittent operation, and a large number of start-stop occasions. At the same time, since the ball bearing seat 222 is interference-fitted with the ball bearing body 221 or interference-fitted with the main shaft 3, the interference force generated can better resist the axial force generated.

[0048] In the present application, as shown in Figure 3 , the bearing structure assembly 2 adopts a sliding bearing assembly 23, which includes a sliding bearing body 231 fixed on the housing 1 and a sliding bearing seat 232 supporting the main shaft 3. The inner wall of the sliding bearing seat 232 is interference-fitted on the sliding bearing body 231, the inner wall of the sliding bearing seat 232 is provided with a plurality of spiral grooves, the main shaft is supported on the inner wall of the sliding bearing seat 232, and working liquid flows into the spiral grooves to lubricate the sliding bearing seat 232 and reduce friction. The sliding bearing seat 232 is made of special graphite or silicon carbide material and has a self-lubricating property.

[0049] 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 first impeller 41 can make the working liquid in the water inlet 111 flow, but due to the rotation of the first impeller 41 in the liquid medium, the first impeller 41 will be forced to move the main shaft 3 in the direction of the water inlet 111, that is, the axial force. In order to solve the damage of the axial force to the pump, a thrust disc 7 is installed behind the second bearing assembly, as shown in Figure 2 or Figure 3 , an arc-shaped groove is arranged on one end face of the thrust disc 7, as shown in Figure 5 . The thrust disc 7 is fixed on the main shaft 3, the thrust disc 7 is located at the rear end of the second bearing seat, and a certain gap is arranged between the end face of the thrust disc 7 and the end face of the second bearing seat. The high-speed rotation of the main shaft 3 drives the high-speed rotation of the thrust disc 7. The high-speed rotation of the thrust disc 7 utilizes the arc-shaped groove to make the working liquid generate an axial high-pressure liquid film between the end face of the thrust disc 7 and the second bearing seat. The axial force makes the main shaft 3 and the thrust disc 7 move to the left, and the axial liquid film formed between the gap makes the thrust disc 7 completely axially float, so that the thrust disc 7 cannot contact the second bearing seat. By virtue of the buffer of the liquid film, an axial force in the same direction as the flow direction is generated, which easily offsets the remaining axial force, achieves the technical effects of no wear and no noise, and balances the axial force of the whole pump, thereby avoiding the failure and loss caused by the unbalanced axial force. In addition, the two end faces of the thrust disc 7 are plated with a layer of titanium silicon, which improves the hardness, wear resistance, and corrosion resistance of the thrust disc 7.

[0050] 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, the combination of Figure 2 And Figure 11 As can be clearly seen, the inside of the hydraulic floating bearing seat 212 is provided with a left detection cavity 2120 and a right detection cavity 2122 located outside 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 the left driving cavity 2126 inside the hydraulic floating bearing seat 212 through the connecting pipe 2121, the right detection cavity 2122 is communicated with the right driving cavity 2123 inside the hydraulic floating bearing seat 212 through the connecting pipe 2121, the driving piston 2124 is arranged between the right driving cavity 2123 and the left driving cavity 2126, so that when the working liquid pressure 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 the flow limiting ring 2130, one end of the flow limiting ring 2130 is annular and located between the hydraulic floating bearing seat 212 and the thrust disc 7, so that when the flow limiting ring 2130 moves, the working liquid flow area between the thrust disc 7 and the hydraulic floating bearing seat 212 can be changed, when the hydraulic floating bearing body 211 and the thrust disc 7 move left and right due to the axial force of the main shaft 3, for example, when the axial force makes the main shaft 3 move left, the "eight" shaped groove on the left side of the hydraulic floating bearing body 211 will relatively move away from the inside of the hydraulic floating bearing seat 212, so that the amount of working liquid transported to the left detection cavity 2120 by the "eight" shaped groove decreases relatively, because the flow area of the right detection cavity 2122 and the "eight" shaped groove increases, the amount of working liquid flowing into the right detection cavity 2122 increases, so that the working liquid pressure in the left driving cavity 2126 is relatively smaller than that in the right driving cavity 2123, the flow limiting ring 2130 has a tendency to move to the right side at this time, so as to reduce the flow area between the hydraulic floating bearing seat 212 and the thrust disc 7, thereby increasing the strength of the high-pressure liquid film between the thrust disc 7 and the hydraulic floating bearing seat 212, so that the strength of the thrust disc 7 pulling the main shaft 3 to the right side increases, and for the same reason, when the main shaft 3 moves to the right side, the flow limiting ring 2130 moves to the left, so as to increase the flow of working liquid, so that the thrust disc 7 moves to the left; under normal working condition, the "eight" shaped groove outside the hydraulic floating bearing body 211 transports the same amount of working liquid to the left detection cavity 2120 and the right detection cavity 2122, the driving piston 2124 remains in the middle position, so that the axial force of the main shaft 3 can be offset when the thrust disc 7 rotates.

[0051] If the thrust plate 7 moves too much, it is difficult for outside personnel to notice it. Therefore, a push rod liquid chamber 2127 is opened in the flow limiting ring 2130, and the push rod piston 2128 is movably installed in the push rod liquid chamber 2127. One end of the push rod piston 2128 is fixedly connected to an ejector push rod 2129 located on one side of the end of the flow limiting ring 2130. A paddle is provided at the end of the ejector push rod 2129. When the paddle intermittently contacts the arc-shaped groove on the end face of the thrust plate 7, the paddle will emit an intermittent metal friction sound. Figure 11 It is obvious that a tension spring 2125 is provided in the push rod fluid chamber 2127 for connecting the push rod piston 2128 and the driving piston 2124, so that the push rod piston 2128 always tends to move toward the driving piston 2124 through the elastic pull of the tension spring 2125, and a limit ball 2132 is movably provided in the push rod fluid chamber 2127, and an arc groove corresponding to the limit ball 2132 is provided on the inner side of the hydraulic floating bearing seat 212, so that when the driving piston 2124 moves, the limit ball 2132 limits it and requires a certain starting force, thereby avoiding the thrust plate 7 When the swing is small, the flow limiting ring 2130 moves frequently. An overflow groove 2131 is provided on the inner side of the flow limiting ring 2130. When the push rod piston 2128 moves to the overflow groove 2131, part of the working fluid in the push rod liquid chamber 2127 will flow out from the overflow groove 2131. At the same time, it also ensures that the liquid medium in the push rod liquid chamber 2127 can be discharged normally. In actual use, when the main shaft 3 drives the hydraulic floating bearing body 211 to deviate to the right to the limit, the driving piston 2124 will move to the leftmost position of the right driving chamber 2123. At this time, , the right detection chamber 2122 is connected to the push rod liquid chamber 2127 through the connecting pipe 2121, and the working medium in the right detection chamber 2122 pushes the push rod piston 2128 to move to the right until the end of the ejector push rod 2129 contacts the thrust plate 7, thereby releasing the sound; similarly, when the main shaft 3 drives the hydraulic floating bearing body 211 to deviate to the left to the limit, the movement of the driving piston 2124 does not reach the connecting pipe 2121, and the end of the ejector push rod 2129 has already contacted the thrust plate 7, thereby releasing the sound, and finally the main shaft 3 is moved to the limit in both directions in the axial direction. After that, the paddles at the end of the push rod 2129 will make a sound; during normal use, the driving piston 2124 is in the middle position. At this time, the tension spring 2125 is subjected to its own elastic tension to pull the push rod piston 2128 toward the driving piston 2124, and the contact in the push rod liquid chamber 2127 is discharged outward from the driving piston 2124. Finally, when the push rod piston 2128 passes over the overflow groove 2131, it will squeeze the working fluid in the push rod liquid chamber 2127, so that the retaining ball 2132 is squeezed into the arc groove of the hydraulic floating bearing seat 212 due to the increased liquid pressure.

[0052] In the present invention, Figure 6As shown, the tail impeller 42, the tail guide vane 62 and the connecting section 131 can not be arranged, forming a micro single-stage shield pump.

[0053] In the present application, as shown in Figure 7 As shown, several tail impellers 42, tail guide vanes 62 and connecting sections 131 can be arranged, and the connecting sections 131 are connected with each other, and the last connecting section 131 is connected and fixed with the water outlet section 132, forming a micro multi-stage shield pump.

[0054] In the present application, the motor body 5 is a permanent magnet synchronous motor, which is made into a shield structure. The rotor assembly 51 is fixed through the shaft shoulder on the main shaft 3, the rotor assembly 51 and the main shaft 3 are tightly matched, and the rotor assembly 51 is completely covered by the rotor shield sleeve, and the rotor shield sleeve is fixed on the main shaft 3 by welding; the stator assembly 52 is located on the radial outside of the rotor assembly 51 and is fixed on the inner wall 121 of the cylinder, and the stator assembly 52 and the inner wall 121 of the cylinder are tightly matched, and the motor wiring is led out from the motor outlet hole 124; the stator shield sleeve 521 is arranged between the rotor assembly 51 and the stator assembly 52, and the stator shield sleeve 521 cooperates with the sealing element arranged in the shell 1 to completely isolate the stator assembly 52 from the working liquid, so as to achieve the shielding effect; a plurality of reinforcing ribs are uniformly distributed on the outside of the stator shield sleeve 521, so as to enhance the structural strength of the stator shield sleeve 521, and a plurality of spiral protrusions are arranged on the inside of the stator shield sleeve 521, so as to increase the disturbance of the internal fluid, increase the flow resistance, and reduce the axial force of the whole pump. Figure 8

[0055] In the present application, the motor body 5 is a high-speed motor, and the high-speed operation of the motor body 5 drives the impeller body 4 to operate at high speed and centrifugal boost. The speed of the high-speed impeller is usually 3-5 times higher than that of the conventional centrifugal pump, and the higher the rotating speed of the impeller body 4 is, the smaller the impeller diameter required to achieve the same flow and head is, so the volume of the expandable micro multi-stage shield pump is greatly reduced.

[0056] In the present application, as shown in Figure 9 As shown, the end face of the supporting cylinder 12 is processed with a plurality of arc-shaped grooves, and the arc-shaped grooves form a sandwich channel 122 through the entire supporting cylinder 12. As shown in Figure 10 As shown, the solid part of the supporting cylinder 12 which is not processed with the arc-shaped grooves is processed with a motor outlet hole 124 which connects the cylinder inner cavity 123 and the outside of the shell 1, so that the motor wiring is completely isolated from the liquid.

[0057] In the present application, the working liquid fills each gap, and the rotor assembly 51 and the stator assembly 52 are completely covered by the working liquid, so that the flowing liquid can well take away the heat generated by the motor body 5, and there is no need to worry about the damage of the motor due to the excessive temperature rise.​

Claims

1. An extensible micro multi-stage shielding pump, comprising a shell (1), a main shaft (3), an impeller body (4) and a motor body (5), 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 shell (1), the main shaft (3), the impeller body (4) and the motor body (5) jointly form a plurality of flow channels for medium flow, a sandwich channel (122) is formed on the outer side of the stator assembly (52) of the shell (1), at least one flow channel passes through the sandwich channel (122), and at least one flow channel passes through the gap between the rotor assembly (51) and the stator assembly (52); a bearing structure assembly (2) is arranged in the shell (1), so that the main shaft (3) can rotate while bearing axial force; the bearing structure assembly (2) is composed of a plurality of hydraulic floating bearing assemblies (21), the hydraulic floating bearing assembly (21) comprises a hydraulic floating bearing body (211) arranged on the main shaft (3) and a hydraulic floating bearing seat (212) arranged on the shell (1); a plurality of thrust discs (7) are arranged in the shell (1), the thrust disc (7) is fixed on the main shaft (3), a plurality of arc-shaped grooves are arranged on the working end face, and the thrust disc (7) is located at the rear end of the bearing seat; a left detection cavity (2120) and a right detection cavity (2122) are formed in the inner side of the hydraulic floating bearing seat (212) and located on the outer side of the hydraulic floating bearing body (211), the left detection cavity (2120) is communicated with a left driving cavity (2126) formed in the inner side of 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 inner side of 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 one end of the driving piston (2124) is fixed with a flow limiting ring (2130) for controlling the flow area of working liquid between the thrust disc (7) and the bearing structure assembly (2); a push rod liquid cavity (2127) containing 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) located on one side of the end of the flow limiting ring (2130), and the end of the ejection push rod (2129) is provided with a tab, when the tab intermittently contacts the arc-shaped groove on the end face of the thrust disc (7), the tab will emit intermittent metal friction sound. The push rod liquid cavity (2127) is provided with a tension spring (2125) for connecting the push rod piston (2128) and the drive piston (2124), the push rod liquid cavity (2127) is movably provided with a limiting ball (2132), and the inner side of the hydraulic floating bearing seat (212) is provided with an arc groove corresponding to the limiting ball (2132). The inner side of the flow limiting ring (2130) is provided with an overflow groove (2131).

2. The scalable micro multi-stage canned pump of claim 1, wherein, The shell (1) comprises a water inlet end (11), a supporting cylinder (12) and a water outlet end (13), the cylinder wall of the supporting cylinder (12) is provided with a sandwich channel (122) for liquid flow, and the water inlet end (11) and the water outlet end (13) are respectively provided with a water inlet (111) and a water outlet discharge port (1321). The impeller body (4) comprises a head impeller (41) located at the front end of the main shaft (3) and a plurality of tail impellers (42) located at the rear end of the main shaft (3), the water outlet end (13) comprises a connecting section (131) matched with the tail impeller (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 a necking structure for collecting fluid. The connecting section (131) and the water outlet section (132) are provided with matched clamping grooves, and the clamping grooves can be fixed by threads or welding.

3. The scalable micro multi-stage canned pump of claim 2, wherein, The matching surface of the hydraulic floating bearing body (211) and the hydraulic floating bearing seat (212) is provided with an "eight" shaped groove, which is used for generating a high-pressure liquid film when rotating at high speed to support the main shaft (3) to float.

4. The scalable micro multi-stage canned pump of claim 2, wherein, The bearing structure assembly (2) is composed of a plurality of ball bearing assemblies (22), the ball bearing assembly (22) comprises a ball bearing body (221) and a ball bearing seat (222), the ball bearing seat (222) is fixed on the shell (1), the outer ring of the ball bearing body (221) is fixed on the ball bearing seat (222), and the inner ring is fixed on the main shaft (3), and the ball bearing body (221) has a self-lubricating property.

5. The scalable micro multi-stage canned pump of claim 2, wherein, The bearing structure assembly (2) is composed of a plurality of sliding bearing assemblies (23), the sliding bearing assembly (23) comprises a sliding bearing body (231) and a sliding bearing seat (232), the sliding bearing seat (232) is fixed on the shell, and the inner wall of the sliding bearing body (231) is provided with a plurality of spiral grooves matched with the main shaft (3), the sliding bearing body (231) is made of special graphite or silicon carbide material and has a self-lubricating property.

6. The scalable micro multi-stage canned pump of claim 2, wherein, The stator assembly (52) is cut off and isolated from the inside of the shell (1) through the cylindrical stator shielding sleeve (521), and the stator shielding sleeve (521) is made of PPS or PEEK plus glass fiber material.

7. The scalable micro multi-stage canned pump of claim 6, wherein, The inner surface of the stator shielding sleeve (521) is provided with protruding or recessed lines, and the lines are spiral.

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