Permanent magnet frequency conversion deep-well pump

Abstract

A permanent magnet frequency conversion deep well pump comprises a water inlet shell and a motor shell arranged on the lower side of the water inlet shell, a motor shaft is arranged in the center in the motor shell, the upper end of the motor shaft upwards penetrates into the water inlet shell and is connected with a rotating shaft through a coupler, a plurality of impellers evenly distributed in the axial direction are arranged on the rotating shaft, and the impellers are covered with impeller shells matched with the impellers. The lowermost impeller shell is attached to the upper end face of the water inlet shell, a water outlet shell is arranged on the upper side of the uppermost impeller shell, a water outlet is formed in the center of the water outlet shell, and a plurality of water inlet holes communicated with the inner space of the water inlet shell are formed in the outer wall of the water inlet shell. The water inlet shell and the water outlet shell are connected through a plurality of pull belts which are evenly distributed in the circumferential direction, and a rotor matched with the motor shaft is arranged outside the motor shaft. The permanent magnet frequency conversion deep-well pump can effectively ensure the stability of the magnetic steel in the motor, effectively improve the magnetic flux density of the rotor, reduce the current of the motor and improve the thermal characteristics of the motor.

Description

Technical Field

[0001] The utility model relates to a deep well pump, in particular to a permanent magnet variable frequency deep well pump. Background Art

[0002] A deep well pump is a pump that is immersed in a groundwater well to suck and transport water. The deep well pump integrates the pump and the motor. The motor is directly arranged just below the water inlet casing of the deep well pump. At this time, the upper end of the motor shaft of the motor is connected to the rotating shaft through a coupling, and a number of impellers evenly distributed axially are arranged on the rotating shaft, and each impeller is covered with an impeller casing, and the top impeller casing is provided with a water outlet casing, and a water outlet is arranged at the center of the water outlet casing, and the water outlet casing and the water inlet casing are connected and tightened by a number of circumferentially evenly distributed tension belts, so as to ensure the stability of the impeller casing located between the water outlet casing and the water inlet casing. When the deep well pump is running, the motor shaft of the motor will drive the rotating shaft to rotate, thereby realizing the synchronous rotation of multiple impellers. At this time, the water inlet hole position on the water inlet casing will generate suction, which continuously sucks the external water flow into the water inlet casing, and then transports it toward the water outlet casing driven by the rotation of the impeller, and initially flows out from the water outlet on the water outlet casing.

[0003] The inner wall of the stator of the motor of a traditional deep well pump is provided with a number of magnets evenly distributed in a circle. The magnets are fixed to the inner wall of the stator by adhesive. The adhesive force of the adhesive is greatly affected by temperature. When the motor is running, heat will inevitably be generated inside the motor, and the heat is difficult to dissipate to the outside of the motor instantly. Therefore, when the magnets are often in a high temperature environment, the adhesive force of the adhesive drops sharply, which eventually affects the stability of the magnets. In severe cases, the magnets will fall off, causing frictional collision between the motor stator and the rotor, posing a serious safety hazard. Summary of the invention

[0004] The utility model aims to solve the existing technical problem by providing a permanent magnet variable frequency deep well pump, which can effectively ensure the stability of the magnetic steel in the motor, and at the same time can effectively increase the magnetic flux density of the rotor, reduce the motor current, and improve the thermal characteristics of the motor.

[0005] The technical solution adopted by the utility model to solve the above technical problems is:

[0006] The utility model discloses a permanent magnet variable frequency deep well pump, comprising a water inlet housing, a motor housing arranged at the lower side of the water inlet housing, a motor shaft being arranged in the center of the motor housing, the upper end of the motor shaft being upwardly penetrated into the water inlet housing and being connected with a rotating shaft through a coupling, a plurality of impellers being evenly distributed in the axial direction being arranged on the rotating shaft, the impeller outer cover being provided with an impeller housing matching therewith, the impeller housing located at the bottom being fitted with the upper end face of the water inlet housing, a water outlet housing being arranged on the upper side of the impeller housing located at the top, a water outlet being arranged in the center of the water outlet housing, a plurality of water inlet holes being interlinked with the internal space thereof being arranged on the outer wall of the water inlet housing, the water inlet housing being connected with the water outlet housing by a plurality of draw belts evenly distributed in the circumference, a rotor matching therewith being arranged outside the motor shaft; a plurality of magnetic steel slots evenly distributed in the circumference being arranged on the upper end face of the rotor; the magnetic steel A matching magnetic steel is provided in the slot, and the upper end of the magnetic steel protrudes upward to the outside of the rotor; a stator is provided on the inner wall of the motor housing and is sleeved on the outside of the rotor; an upper port communicating with the internal space is provided on the upper end surface of the motor housing; a lower port communicating with the internal space is provided on the lower end surface of the motor housing; an upper end cover for shielding the upper port is provided on the upper end surface of the motor housing; an upper limit structure is provided between the upper inner wall of the upper end cover and the upper end surface of the rotor; an upper bearing hole is provided at the center of the upper end cover; an upper bearing sleeved on the outside of the motor shaft is provided in the upper bearing hole; a lower end cover for shielding the lower port is provided on the lower end surface of the motor housing; a lower bearing groove is provided at the center of the lower inner wall of the lower end cover; a lower bearing sleeved on the outside of the lower end of the motor shaft is provided in the lower bearing groove; a lower limit structure matching the rotor is provided at the lower part of the motor shaft.

[0007] The upper limit structure comprises a limit sleeve sleeved outside the motor shaft; a limit plate is provided on the outer wall of the lower end of the limit sleeve, which is fitted with the upper end face of the rotor; a plurality of limit grooves corresponding to the positions of the magnetic steel slots are provided on the lower surface of the limit plate, and the upper end of the magnetic steel is clamped in the limit grooves; a plurality of clamping grooves uniformly distributed in a circumference are provided on the inner wall of the limit sleeve; a plurality of upper key grooves corresponding to the positions of the clamping grooves are provided on the outer wall of the motor shaft; an upper flat key matching therewith is provided in the upper key groove, and the outer end of the upper flat key protrudes into the clamping groove; a limit tube outside the motor shaft is provided between the upper inner wall of the upper end cover and the upper end face of the limit sleeve; an annular auxiliary part is provided on the upper inner wall of the upper end cover; the outer wall of the auxiliary part is fitted with the inner wall of the upper port, and a set of auxiliary bearings outside the upper end of the limit tube is provided in the auxiliary part; a plurality of circumferentially uniformly distributed positioning grooves are provided on the upper end face of the limit sleeve; a plurality of positioning blocks matching the positioning grooves are provided on the lower end face of the limit tube.

[0008] The upper end surface of the rotor is provided with a plurality of evenly distributed positioning holes; the lower surface of the limiting plate is provided with a plurality of positioning rods matching the positioning holes.

[0009] The lower limit structure includes a plurality of positioning notches uniformly arranged on the inner wall of the lower end of the rotor in a circumferential manner; the outer wall of the lower part of the motor shaft is provided with a plurality of lower keyways corresponding to the positions of the positioning notches; a lower flat key matching the lower keyway is provided in the lower keyway, and the outer end of the lower flat key protrudes into the positioning notch.

[0010] The outer wall of the lower end of the water inlet housing is provided with an upper fixing plate that fits with the upper surface of the upper end cover; the outer edge of the upper fixing plate is provided with a plurality of upper countersunk holes evenly distributed in a circumference; the outer edge of the upper end cover is provided with a plurality of upper through holes coaxial with the upper countersunk holes; the upper end surface of the motor housing is provided with a plurality of upper screw holes coaxial with the upper through holes; an upper screw passes downward through the upper countersunk hole and the upper through hole in sequence and is screwed into the upper screw hole.

[0011] The outer edge of the lower end cover is provided with a plurality of sinking holes evenly distributed in a circumference; the lower end surface of the motor housing is provided with a plurality of lower screw holes coaxial with the sinking holes; a lower screw passes upward through the sinking holes and is screwed into the lower screw holes.

[0012] Symmetrical elastic grooves are arranged on both sides of the magnetic steel slot; fastening wings are arranged at the position where the magnetic steel slot and the elastic groove intersect, and the magnetic steel is located between the fastening wings on both sides.

[0013] The beneficial effects of the utility model are:

[0014] Compared with the prior art, the permanent magnet variable frequency deep well pump adopting the structure of the utility model installs the magnet in the magnet slot of the rotor, which can realize the synchronous rotation of the magnet and the rotor. The design of adding magnet in the rotor can effectively improve the magnetic flux density of the rotor, further improve the efficiency and power density of the motor, and at the same time can effectively reduce the motor current and improve the thermal characteristics of the motor. The existence of the lower flat key can effectively limit the downward movement of the rotor, and the existence of the upper end cover, the limit tube and the limit sleeve can effectively limit the upward movement of the rotor, thereby effectively fixing the rotor on the motor shaft, and the upper flat key can effectively limit the rotation of the limit sleeve. At this time, the limit plate cannot rotate relative to the motor at the same time. When the machine shaft rotates, when the upper end of the magnet is stuck in the limit groove on the lower surface of the limit plate, combined with the existence of the lower flat key, the rotor can be effectively prevented from rotating relative to the motor shaft, and the synchronous rotation of the rotor and the motor shaft can be achieved, effectively ensuring the stability of the motor during operation. The limit tube presses the limit plate against the upper end surface of the rotor, which can effectively limit the magnet in the magnet slot and effectively prevent the magnet from falling out of the magnet slot. This way of fixing the magnet will not be affected by the heat generated when the motor is running, and can always maintain a stable state, thereby avoiding the situation where the stator and rotor collide and rub due to the falling of the magnet, effectively eliminating safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view of the permanent magnet variable frequency deep well pump of the utility model;

[0016] Figure 2 yes Figure 1 An enlarged view of part A;

[0017] Figure 3 yes Figure 1 An enlarged view of part B;

[0018] Figure 4 It is a partial cross-sectional view of the permanent magnet variable frequency deep well pump of the utility model;

[0019] Figure 5 It is a schematic diagram of the structure when a magnet is installed in one of the magnet slots on the upper end surface of the rotor. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0021] See also Figures 1 to 5 The utility model provides a permanent magnet variable frequency deep well pump, comprising a water inlet housing 1, a motor housing 2 arranged at the lower side of the water inlet housing 1, a motor shaft 3 is arranged in the center of the motor housing 2, the upper end of the motor shaft 3 is upwardly penetrated into the water inlet housing 1 and is connected to a rotating shaft 5 through a coupling 4, a plurality of impellers 6 which are evenly distributed in the axial direction are arranged on the rotating shaft 5, and an impeller housing 7 which matches the impeller 6 is covered on the outer side of the impeller 6, the impeller housing 7 located at the bottom is fitted with the upper end surface of the water inlet housing 1, a water outlet housing 8 is arranged on the upper side of the impeller housing 7 located at the top, a water outlet housing 8 is arranged at the center of the water outlet housing 8, a plurality of water inlet holes 10 which are connected with the internal space of the water inlet housing 1 are arranged on the outer wall of the water inlet housing 1, the water inlet housing 1 and the water outlet housing 8 are connected by a plurality of circumferentially evenly distributed draw belts 11, the motor shaft 3 is provided with a rotor 12 which matches the motor shaft 3; a plurality of circumferentially evenly distributed magnetic steel slots 13 are arranged on the upper end surface of the rotor 12; a plurality of circumferentially evenly distributed magnetic steel slots 13 are arranged in the magnetic steel slots 13 Its matching magnetic steel 14, the upper end of the magnetic steel 14 protrudes upward to the outside of the rotor 12; the inner wall of the motor housing 2 is provided with a stator 15 that is sleeved on the outside of the rotor 12; the upper end surface of the motor housing 2 is provided with an upper port 16 that is connected to its internal space; the lower end surface of the motor housing 2 is provided with a lower port 17 that is connected to its internal space; the upper end surface of the motor housing 2 is provided with an upper end cover 18 that shields the upper port; an upper limit structure is provided between the upper inner wall of the upper end cover 18 and the upper end surface of the rotor 12; an upper bearing hole 19 is provided at the center of the upper end cover 18; an upper bearing 20 that is sleeved on the outside of the motor shaft 3 is provided in the upper bearing hole 19; a lower end cover 21 that shields the lower port is provided on the lower end surface of the motor housing 2; a lower bearing groove 22 is provided at the center of the lower inner wall of the lower end cover 21; a lower bearing 23 that is sleeved on the outside of the lower end of the motor shaft 3 is provided in the lower bearing groove 22; a lower limit structure that matches the rotor 12 is provided at the lower part of the motor shaft 3.

[0022] The upper limit structure includes a limit sleeve 24 sleeved on the outside of the motor shaft 3; a limit plate 25 is provided on the outer wall of the lower end of the limit sleeve 24, which is in contact with the upper end surface of the rotor 12; a plurality of limit grooves 26 corresponding to the position of the magnetic steel slot 13 are provided on the lower surface of the limit plate 25, and the upper end of the magnetic steel 14 is clamped in the limit groove 26; a plurality of circumferentially evenly distributed clamping grooves 27 are provided on the inner wall of the limit sleeve 24; a plurality of upper key grooves 28 corresponding to the position of the clamping grooves 27 are provided on the outer wall of the motor shaft 3; an upper flat key 29 matching with the upper key groove 28 is provided in the upper key groove 28, and the upper flat key 29 is provided in the upper key groove 28. The outer end of the key 29 protrudes into the locking groove 27; a set of limiting tubes 30 outside the motor shaft 3 is provided between the upper inner wall of the upper end cover 18 and the upper end surface of the limiting sleeve 24; an annular auxiliary part 31 is provided on the upper inner wall of the upper end cover 18; the outer wall of the auxiliary part 31 fits with the inner wall of the upper port 16, and a set of auxiliary bearings 32 outside the upper end of the limiting tube 30 is provided in the auxiliary part 31; the upper end surface of the limiting sleeve 24 is provided with a plurality of positioning grooves 33 evenly distributed around the circumference; the lower end surface of the limiting tube 30 is provided with a plurality of positioning blocks 34 matching the positioning grooves 33.

[0023] The upper end surface of the rotor 12 is provided with a plurality of evenly distributed positioning holes 35 ; the lower surface of the limiting plate 25 is provided with a plurality of positioning rods 36 matching the positioning holes 35 .

[0024] The lower limit structure includes a plurality of positioning notches 37 uniformly arranged on the inner wall of the lower end of the rotor 12 in a circumferential manner; the lower outer wall of the motor shaft 3 is provided with a plurality of lower keyways 38 corresponding to the positions of the positioning notches 37; a lower flat key 39 matching the lower keyway 38 is provided in the lower keyway 38, and the outer end of the lower flat key 39 protrudes into the positioning notch 37.

[0025] The outer wall of the lower end of the water inlet housing 1 is provided with an upper fixing plate 40 that fits with the upper surface of the upper end cover 18; the outer edge of the upper fixing plate 40 is provided with a plurality of upper countersunk holes 41 that are evenly distributed in a circumference; the outer edge of the upper end cover 18 is provided with a plurality of upper through holes 42 that are coaxial with the upper countersunk holes 41; the upper end surface of the motor housing 2 is provided with a plurality of upper screw holes 43 that are coaxial with the upper through holes 42; an upper screw 44 passes downward through the upper countersunk hole 41 and the upper through hole 42 in sequence and is screwed into the upper screw hole 43.

[0026] The outer edge of the lower end cover 21 is provided with a plurality of circumferentially evenly distributed sinking holes 45 ; the lower end surface of the motor housing 2 is provided with a plurality of lower screw holes 46 coaxial with the sinking holes 45 ; a lower screw 47 passes upward through the sinking holes 45 and is screwed into the lower screw holes 46 .

[0027] Symmetrical elastic grooves 48 are provided on both sides of the magnetic steel slot 13 ; fastening wings 49 are provided at the position where the magnetic steel slot 13 and the elastic groove 48 intersect, and the magnetic steel 14 is located between the fastening wings 49 on both sides.

[0028] The method of using the utility model is as follows:

[0029] The stator 15 can generate a rotating magnetic field through alternating current, and the magnet 14 installed on the rotor 12, as a permanent magnet, will be affected by the rotating magnetic field to generate a torque, which can realize the rotation of the motor shaft 3. The magnitude of the torque can be adjusted by changing the frequency of the current, thereby realizing the speed regulation of the motor.

[0030] The magnet 14 is installed in the magnet slot 13 of the rotor 12, so that the synchronous rotation of the magnet 14 and the rotor 12 can be achieved. The design of adding the magnet 14 in the rotor 12 can effectively improve the magnetic flux density of the rotor 12, further improve the efficiency and power density of the motor, and effectively reduce the motor current and improve the thermal characteristics of the motor. The existence of the lower flat key 39 can effectively limit the downward movement of the rotor, and the existence of the upper end cover 18, the limit tube 30 and the limit sleeve 24 can effectively limit the upward movement of the rotor 12, thereby effectively fixing the rotor 12 on the motor shaft 3, and the upper flat key 29 can effectively limit the rotation of the limit sleeve 24. At this time, the limit plate 25 cannot rotate relative to the motor shaft 3 at the same time. When the upper end of 14 is stuck in the limit groove 26 on the lower surface of the limit plate 25, combined with the existence of the lower flat key 39, the rotor 12 can be effectively prevented from rotating relative to the motor shaft 3, the rotor 12 and the motor shaft 3 can be synchronously rotated, and the stability of the motor during operation is effectively guaranteed. The limit tube 30 presses the limit plate 25 on the upper end surface of the rotor, which can effectively limit the magnet 14 in the magnet slot 13, and effectively prevent the magnet 14 from falling out of the magnet slot 13. This fixing method of the magnet 14 will not be affected by the heat generated during the operation of the motor, and can always maintain a stable state, thereby avoiding the situation where the magnet 14 falls off and causes the stator and the rotor 12 to collide and rub, effectively eliminating safety hazards.

[0031] An upper bearing hole 19 is provided at the center of the upper end cover 18, and an upper bearing 20 is provided in the upper bearing hole 19 and is sleeved on the outside of the motor shaft 3. A lower bearing groove 22 is provided at the center of the lower inner wall of the lower end cover 21, and a lower bearing 23 is provided in the lower bearing groove 22 and is sleeved on the outside of the lower end of the motor shaft 3. The existence of the upper bearing 20 and the lower bearing 23 can not only support the motor shaft 3, but also ensure the smoothness of the rotation of the rotor 12 driven by the motor shaft 3.

[0032] An annular auxiliary part 31 is provided on the inner wall of the upper side of the upper end cover 18, and the outer wall of the auxiliary part 31 is fitted with the inner wall of the upper port. A set of auxiliary bearings 32 outside the upper end of the limiting tube 30 is provided in the auxiliary part 31. The upper end surface of the limiting sleeve 24 is provided with a plurality of positioning grooves 33 evenly distributed in a circumference, and the lower end surface of the limiting tube 30 is provided with a plurality of positioning blocks 34 matching the positioning grooves 33. The cooperation of the positioning blocks 34 and the positioning grooves 33 can make the limiting sleeve 24 and the limiting tube 30 stuck and fixed. When the rotor 12 rotates with the motor shaft 3, the limiting sleeve 24 will rotate synchronously with the limiting tube 30. At this time, the auxiliary bearing 32 can effectively ensure the smoothness of the limiting tube 30 during rotation, thereby further ensuring the smoothness of the motor shaft 3 during rotation.

[0033] The upper end surface of the rotor 12 is provided with a plurality of evenly distributed positioning holes 35, and the lower surface of the limiting plate 25 is provided with a plurality of positioning rods 36 matching the positioning holes 35. The presence of the positioning rods 36 can effectively further ensure the stability of the limiting plate 25 when it is pressed on the upper end surface of the rotor 12. At the same time, the limiting groove 26 on the limiting plate 25 further limits the magnetic steel 14, thereby further ensuring the stability of the magnetic steel 14.

[0034] An upper fixing plate 40 is provided on the outer wall of the lower end of the water inlet housing 1 and is fitted with the upper surface of the upper end cover 18. A plurality of upper countersunk holes 41 are provided on the outer edge of the upper fixing plate 40 and are evenly distributed in a circumference. A plurality of upper through holes 42 coaxial with the upper countersunk holes 41 are provided on the outer edge of the upper end cover 18. A plurality of upper screw holes 43 coaxial with the upper through holes 42 are provided on the upper end surface of the motor housing 2. An upper screw 44 passes downwardly through the upper countersunk holes 41 and the upper through holes 42 in sequence and is screwed into the upper screw holes 43. This fixing method facilitates the disassembly and assembly between the water inlet housing 1 and the upper end cover 18, and the disassembly and assembly between the upper end cover 18 and the motor housing 2, thereby facilitating the disassembly and assembly of components inside the motor housing 2.

[0035] The outer edge of the lower end cover 21 is provided with a plurality of sinking holes 45 evenly distributed in a circle, and the lower end surface of the motor housing 2 is provided with a plurality of lower screw holes 46 coaxial with the sinking holes 45. A lower screw 47 passes upward through the sinking holes 45 and is screwed into the lower screw hole 46. This fixing method facilitates the disassembly and assembly between the lower end cover 21 and the motor housing 2, thereby facilitating the maintenance and replacement of components inside the motor housing 2.

[0036] Symmetrical elastic grooves 48 are provided on both sides of the magnetic steel slot 13, and fastening wings 49 are provided at the position where the magnetic steel slot 13 and the elastic groove 48 intersect. The magnetic steel 14 is located between the fastening wings 49 on both sides. The existence of the elastic groove 48 enables the fastening wings 49 to deform to a certain extent after being compressed. Therefore, when the magnetic steel 14 is squeezed between the fastening wings 49 on both sides, the fastening wings 49 are compressed and deformed and generate elasticity. This elasticity holds the magnetic steel 14 between the fastening wings 49 on both sides, and at the same time facilitates the insertion of the magnetic steel 14 into the magnetic steel slot 13, and also facilitates the removal of the magnetic steel 14.

Claims

1. A permanent magnet variable frequency deep well pump, comprising a water inlet housing, a motor housing arranged at the lower side of the water inlet housing, a motor shaft is arranged in the center of the motor housing, the upper end of the motor shaft is upwardly penetrated into the water inlet housing and connected to a rotating shaft through a coupling, a plurality of impellers evenly distributed in the axial direction are arranged on the rotating shaft, the impeller outer cover is provided with an impeller housing matching therewith, the impeller housing at the bottom is fitted with the upper end surface of the water inlet housing, a water outlet housing is arranged on the upper side of the impeller housing at the top, a water outlet is arranged in the center of the water outlet housing, a plurality of water inlet holes are arranged on the outer wall of the water inlet housing which are connected with the internal space thereof, the water inlet housing and the water outlet housing are connected by a plurality of drawstrings evenly distributed circumferentially, and are characterized in that: The motor shaft is provided with a rotor matching therewith; the upper end surface of the rotor is provided with a plurality of magnetic steel slots evenly distributed in a circumference; the magnetic steel slots are provided with magnetic steels matching therewith, and the upper ends of the magnetic steels protrude upward to the outside of the rotor; the inner wall of the motor housing is provided with a stator sleeved outside the rotor; the upper end surface of the motor housing is provided with an upper port intersecting with its internal space; the lower end surface of the motor housing is provided with a lower port intersecting with its internal space; the upper end surface of the motor housing is provided with an upper end cover shielding the upper port; an upper limit structure is provided between the upper inner wall of the upper end cover and the upper end surface of the rotor; an upper bearing hole is provided at the center of the upper end cover; an upper bearing sleeved outside the motor shaft is provided in the upper bearing hole; a lower end cover shielding the lower port is provided at the lower end surface of the motor housing; a lower bearing groove is provided at the center of the lower inner wall of the lower end cover; a lower bearing sleeved outside the lower end of the motor shaft is provided in the lower bearing groove; a lower limit structure matching the rotor is provided at the lower part of the motor shaft.

2. A permanent magnet variable frequency deep well pump according to claim 1, characterized in that: The upper limit structure comprises a limit sleeve sleeved outside the motor shaft; a limit plate is provided on the outer wall of the lower end of the limit sleeve, which is fitted with the upper end face of the rotor; a plurality of limit grooves corresponding to the positions of the magnetic steel slots are provided on the lower surface of the limit plate, and the upper end of the magnetic steel is clamped in the limit grooves; a plurality of clamping grooves uniformly distributed in a circumference are provided on the inner wall of the limit sleeve; a plurality of upper key grooves corresponding to the positions of the clamping grooves are provided on the outer wall of the motor shaft; an upper flat key matching therewith is provided in the upper key groove, and the outer end of the upper flat key protrudes into the clamping groove; a limit tube outside the motor shaft is provided between the upper inner wall of the upper end cover and the upper end face of the limit sleeve; an annular auxiliary part is provided on the upper inner wall of the upper end cover; the outer wall of the auxiliary part is fitted with the inner wall of the upper port, and a set of auxiliary bearings outside the upper end of the limit tube is provided in the auxiliary part; a plurality of circumferentially uniformly distributed positioning grooves are provided on the upper end face of the limit sleeve; a plurality of positioning blocks matching the positioning grooves are provided on the lower end face of the limit tube.

3. A permanent magnet variable frequency deep well pump according to claim 2, characterized in that: The upper end surface of the rotor is provided with a plurality of evenly distributed positioning holes; the lower surface of the limiting plate is provided with a plurality of positioning rods matching the positioning holes.

4. A permanent magnet variable frequency deep well pump according to claim 1, characterized in that: The lower limit structure includes a plurality of positioning notches uniformly arranged on the inner wall of the lower end of the rotor in a circumferential manner; The outer wall of the lower part of the motor shaft is provided with a plurality of lower key grooves corresponding to the positions of the positioning notches; the lower key grooves are provided with lower flat keys matching therewith, and the outer ends of the lower flat keys protrude into the positioning notches.

5. A permanent magnet variable frequency deep well pump according to claim 1, characterized in that: The outer wall of the lower end of the water inlet housing is provided with an upper fixing plate that fits with the upper surface of the upper end cover; the outer edge of the upper fixing plate is provided with a plurality of upper countersunk holes evenly distributed in a circumference; the outer edge of the upper end cover is provided with a plurality of upper through holes coaxial with the upper countersunk holes; the upper end surface of the motor housing is provided with a plurality of upper screw holes coaxial with the upper through holes; an upper screw passes downward through the upper countersunk hole and the upper through hole in sequence and is screwed into the upper screw hole.

6. A permanent magnet variable frequency deep well pump according to claim 1, characterized in that: The outer edge of the lower end cover is provided with a plurality of sinking holes evenly distributed in a circumference; the lower end surface of the motor housing is provided with a plurality of lower screw holes coaxial with the sinking holes; a lower screw passes upward through the sinking holes and is screwed into the lower screw holes.

7. A permanent magnet variable frequency deep well pump according to claim 1, characterized in that: Symmetrical elastic grooves are arranged on both sides of the magnetic steel slot; fastening wings are arranged at the position where the magnetic steel slot and the elastic groove intersect, and the magnetic steel is located between the fastening wings on both sides.

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