A special rotor for rare earth praseodymium-neodymium permanent magnet submersible pump motor

Abstract

The present invention relates to the technical field of water-immersed submersible pump motors, and in particular to a special rotor for rare earth praseodymium-neodymium permanent magnet submersible pump motors, comprising a central iron plate and a rotor jacket, wherein the central iron plate is inserted in parallel in the rotor jacket, a lower half shaft is installed at one end of the central iron plate, and an upper half shaft is installed at the other end, the axes of the upper half shaft and the lower half shaft are on the same straight line, and the upper half shaft and the lower half shaft are symmetrical to the central iron plate, and half-moon-shaped magnetic materials are glued to the upper and lower sides of the central iron plate. The cast aluminum and copper bar cage of this rotor only works at startup, inducing current and generating rotation. After startup, the praseodymium-neodymium permanent magnet magnetic field forcibly pulls the rotor speed to synchronous operation. At this time, the number of revolutions is the same as the power supply frequency, there is no speed difference between the stator and the rotor, and the rotor cage does not induce AC current, so the motor reactive power consumption is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of water-immersed submersible pump motors, and in particular to a special rotor for rare earth praseodymium-neodymium permanent magnet submersible pump motors. Background Art

[0002] The asynchronous starting permanent magnet synchronous motor rotor specially designed for submersible pump motors is self-started by the 5Hz grid frequency and is pulled into synchronous operation by the super strong praseodymium-neodymium permanent magnet magnetic field. After synchronization, the rotor has no induced AC current, which reduces reactive power loss. It has a reasonable structure and reliable operation, especially the power consumption can be greatly reduced, and the power can reach above 0.9 or even capacitive.

[0003] At present, the common induction asynchronous motors used in large quantities have the disadvantages of large reactive power loss, high power consumption, low efficiency, and low power factor. The permanent magnet synchronous motor rotor solves the problems caused by the asynchronous motor and is the future development trend of "low consumption and energy saving". Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art of large reactive power loss, low efficiency and high power consumption of asynchronous induction motors of submersible pumps, and to propose a special rotor for rare earth praseodymium-neodymium permanent magnet submersible pump motors.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor is designed, comprising a central iron plate and a rotor jacket, the central iron plate is inserted in parallel in the rotor jacket, a lower half shaft is installed at one end of the central iron plate, and an upper half shaft is installed at the other end, the axes of the upper half shaft and the lower half shaft are on the same straight line, and the upper half shaft and the lower half shaft are symmetrical with respect to the central iron plate, half-moon-shaped magnetic materials are glued on the upper and lower sides of the central iron plate, the outer wall of the half-moon-shaped magnetic material is in close contact with the inner wall of the rotor jacket, key slots are correspondingly provided on one side of the central iron plate and on the inner wall of the rotor jacket, the central iron plate and the rotor jacket are locked by embedding key strips in the key slots, annular silicon steel sheets are installed at the ports at both ends of the rotor jacket, and key slots are correspondingly provided on the inner side of the silicon steel sheet and the rotor jacket.

[0007] Preferably, the half-moon-shaped magnetic material and the central iron plate are both sprayed with epoxy structural adhesive.

[0008] Preferably, the central iron plate is specifically an iron plate made of electrical pure iron, with a brand of DT4E-DT4C.

[0009] Preferably, the half-moon shaped magnetic material is a half-moon shaped block sintered from a mixture of praseodymium, neodymium, iron and boron, and its brand is N-52.

[0010] Preferably, a plurality of pear-shaped flat-bottomed cast aluminum grooves are evenly spaced on the body of the silicon steel sheet, and long ridge-shaped magnetic isolation bridges are symmetrically arranged on both sides of the body of the silicon steel sheet, and the specific number of the pear-shaped flat-bottomed cast aluminum grooves is 16.

[0011] Preferably, the half-moon-shaped magnetic material is bonded to both sides of the central iron plate, and the bonding material used is fast epoxy resin.

[0012] Preferably, the adhesive used to press the central iron plate and the half-moon-shaped magnetic material into the rotor casing is an epoxy structural adhesive such as TY5324, TY5326 and JL6236 with an accelerator JL-7649.

[0013] The present invention also provides a method for preparing a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor, and the specific steps are as follows:

[0014] S1. Cut 45# round steel and make the upper and lower half shafts of specified size by lathe. Punch holes at one end of the upper and lower half shafts and slot them at the other end. The width of the slot is strictly consistent with the middle iron plate.

[0015] S2. Insert the middle iron plate into the slots of the upper and lower half shafts, adjust the center distance and weld them to form a whole shaft frame;

[0016] S3, turn and grind the machine tool on the shaft frame to the specified error, and grind the burrs on the center iron plate caused by turning;

[0017] S4, stick two half-moon shaped magnetic materials on both sides of the middle iron plate with epoxy resin, and form the rotor shaft after solidification;

[0018] S5, coating the outer circumference of the rotor shaft with structural adhesive, and pressing the rotor shaft together with the key strip into the rotor jacket and the keyway 10, and forming a permanent magnet rotor after the structural adhesive is cured;

[0019] S6, fine turning the rotor blank on a lathe until a specified error is reached;

[0020] S7, fine grinding the machined rotor on a grinder;

[0021] S8, correct the dynamic balance of the ground rotor;

[0022] S9. The rotor is magnetized and tested in the inspection room. If qualified, it will be installed; if unqualified, it will be scrapped and disassembled and treated as waste.

[0023] The invention proposes a special rotor for rare earth praseodymium-neodymium permanent magnet submersible pump motor, which has the beneficial effect that the special rotor for rare earth praseodymium-neodymium permanent magnet submersible pump motor in the cast aluminum and copper bar cage only works at startup, induces current and generates rotation, and after startup, the praseodymium-neodymium permanent magnetic field forcibly pulls the rotor speed to synchronous operation. At this time, the number of revolutions is the same as the power supply frequency, there is no speed difference between the stator and the rotor, and the rotor cage does not induce AC current, so the motor reactive power consumption is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is an exploded view of a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor proposed by the present invention.

[0025] Figure 2 This is an enlarged view of the internal structure of a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor proposed by the present invention.

[0026] Figure 3 This is a partial enlarged view of a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor proposed by the present invention.

[0027] Figure 4 The figure is a side view of a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor proposed by the present invention.

[0028] Figure 5 This is a structural diagram of a rotor silicon steel sheet specially used for a rare earth praseodymium-neodymium permanent magnet submersible pump motor proposed by the present invention.

[0029] Figure 6 This is a diagram for installing a rotor casing of a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor proposed by the present invention.

[0030] Figure 7 The present invention provides a schematic structural diagram of a special rotor key bar for a rare earth praseodymium-neodymium permanent magnet submersible pump motor.

[0031] In the figure: silicon steel sheet 1, upper half shaft 2, lower half shaft 3, middle iron plate 4, half-moon shaped magnetic material 5, key bar 6, long ridge type magnetic isolation bridge 7, pear-shaped flat bottom cast aluminum groove 8, rotor jacket 9, keyway 10. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0033] Reference Figure 1-7A rotor dedicated to a rare earth praseodymium-neodymium permanent magnet submersible pump motor comprises a central iron plate 4 and a rotor jacket 9. The central iron plate 4 is specifically an iron plate made of electrical pure iron, with a brand name of DT4E-DT4C. The central iron plate 4 is inserted in parallel in the rotor jacket 9. A lower half shaft 3 is installed at one end of the central iron plate 4, and an upper half shaft 2 is installed at the other end. The axes of the upper half shaft 2 and the lower half shaft 3 are on the same straight line, and the upper half shaft 2 and the lower half shaft 3 are symmetrical with respect to the central iron plate 4. Half-moon-shaped magnetic materials 5 are glued on both sides of the central iron plate 4. The half-moon-shaped magnetic materials 5 are half-moon-shaped blocks sintered by mixing praseodymium, neodymium, iron and boron, with a brand name of N-52. The outer wall of the half-moon-shaped magnetic material 5 is in close contact with the inner wall of the rotor jacket 9. The half-moon-shaped magnetic material 5 is glued on both sides of the central iron plate 4, and the adhesive material used is a fast epoxy resin. Epoxy structural adhesive is sprayed on the half-moon shaped magnetic material 5 and the center iron plate 4. The adhesive used for pressing the center iron plate 4 and the half-moon shaped magnetic material 5 into the rotor jacket 9 is epoxy structural adhesive TY5324, TY5326 and JL6236 with promoter JL-7649. Key grooves 10 are correspondingly opened on one side of the center iron plate 4 and the inner wall of the rotor jacket 9. The center iron plate 4 and the rotor jacket 9 are locked by embedding key bars 6 in the key grooves 10. Circular silicon steel sheets 1 are installed at the ends of the rotor jacket 9. A plurality of pear-shaped flat-bottomed cast aluminum grooves 8 are evenly spaced on the silicon steel sheet 1, and long ridge-type magnetic isolation bridges 7 are symmetrically arranged on both sides of the silicon steel sheet 1. The specific number of pear-shaped flat-bottomed cast aluminum grooves 8 is 16. Key grooves 10 are opened on the inner side of the silicon steel sheet 1 and corresponding to the rotor jacket 9.

[0034] Compared with the rotor of the traditional induction motor, the rotor of the present invention has a cast aluminum and copper bar cage that only works at startup, inducing current and generating rotation. After startup, the praseodymium-neodymium permanent magnetic field forcibly pulls the rotor speed to synchronous operation. At this time, the number of revolutions is the same as the power supply frequency, there is no speed difference between the stator and the rotor, and the rotor cage does not induce AC current, so the reactive power consumption of the motor is greatly reduced.

[0035] The present invention also provides a method for preparing a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor, and the specific steps are as follows:

[0036] S1. Cut 45# round steel and make upper and lower half shafts of specified size through lathe. Punch holes at one end of the upper and lower half shafts and slot them at the other end. The width of the slot is strictly consistent with the middle iron plate 4.

[0037] S2. Insert the middle iron plate into the slots of the upper and lower half shafts, adjust the center distance and weld them to form a whole shaft frame;

[0038] S3, turning and grinding the machine tool on the shaft frame to a specified error, and grinding the burrs generated by turning on the middle iron plate 4;

[0039] S4, two half-moon-shaped magnetic materials 5 are glued to both sides of the middle iron plate 4 with epoxy resin, and after solidification, they form the complete rotor shaft;

[0040] S5, apply structural adhesive to the outer circumference of the rotor shaft, and press it together with the key bar 6 into the rotor jacket 9 and the key slot 10, and form a permanent magnet rotor after the structural adhesive is cured;

[0041] S6, fine turning the rotor blank on a lathe until a specified error is reached;

[0042] S7, fine grinding the machined rotor on a grinder;

[0043] S8, correct the dynamic balance of the ground rotor;

[0044] S9. The rotor is magnetized and tested in the inspection room. If qualified, it will be installed; if unqualified, it will be scrapped and disassembled and treated as waste.

[0045] Note: 1. The rotor is magnetized radially, with the magnetic poles S and N facing each other. 2. The cast aluminum copper rotor is different from the conventional rotor. If the cast aluminum area of ​​the rotor is too large, the silicon steel sheet area of ​​the rotor punching will be reduced, which will inevitably affect the magnetic permeability; if the cast aluminum area is too small, the starting performance will be poor. In view of the above conditions, the rotor punching of the present invention adopts an elliptical flat-bottomed groove type and a long-ribbed magnetic isolation bridge plate, and develops a set of transfer rotor punching dies, which increases the cast aluminum area without increasing the magnetic resistance.

[0046] Asynchronous starting, the working principle of the permanent magnet synchronous motor rotor is as follows: At the beginning of starting, the motor rotor is the same as an ordinary motor. When the stator winding is fed with 50Hz three-phase AC, a rotating collision field consistent with the frequency is generated. Under the action of the rotating collision field, the rotor generates an induced electromotive force and forms an induced magnetic field. Under the interaction of the collision field formed by the stator rotating magnetic field and the rotor induced electromotive force, the rotor begins to rotate. When the asynchronous speed is reached, the super-strong magnetic field of the praseodymium-neodymium magnetic material is forcibly pulled into synchronization. At this time, the stator rotating collision field is synchronized with the rotor rotation speed. Since there is no slip, the cast aluminum copper grate cage no longer induces AC electromotive force and relies on the praseodymium-neodymium permanent magnetic field to drive the rotor to rotate and do work.

[0047] When the grid voltage decreases, the motor speed of the present invention will not decrease, and the lift and flow rate of the water pump will not decrease as the grid voltage decreases.

[0048] The present invention works in a synchronous operation state. Since there is no speed difference between the rotating magnetic field generated by the stator and the rotor, there is no induced current in the rotor cast aluminum copper grate cage, and the rotor has no reactive loss, so the power consumption of the whole machine is greatly reduced. For example, the rated working current of an ordinary 200 type 800-22-7.5kW motor is 18A, while the rated working current of a 200 type 80-22-7.5kW motor with a permanent magnet synchronous rotor is only 15.45A.

[0049] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor, characterized in that: The specific steps are as follows: S1. Cut 45# round steel into upper and lower half shafts of specified size by lathe, punch holes at one end of the upper and lower half shafts, and slot the other end. The width of the slot is strictly consistent with the middle iron plate (4); S2. Insert the middle iron plate into the slots of the upper and lower half shafts, adjust the center distance and weld them to form an integral shaft frame; S3, turning and grinding the machine tool on the shaft frame to a specified error, and grinding the burrs generated by turning on the middle iron plate (4); S4, sticking two half-moon shaped magnetic materials (5) on both sides of the middle iron plate (4) with epoxy resin, and forming a complete rotor shaft after solidification; S5, applying structural adhesive to the outer circumference of the entire rotor shaft, and pressing it together with the key strip (6) into the rotor outer sleeve (9) and the key slot (10), and forming a permanent magnet rotor after the structural adhesive is cured; S6, fine turning the permanent magnet rotor on a lathe until a specified error is reached; S7, fine grinding the finely turned rotor on a grinder; S8, correct the dynamic balance of the ground rotor; S9. The rotor is magnetized and tested in the inspection room. If it is qualified, it will be installed. If it is unqualified, it will be scrapped and disassembled as waste. The rare earth praseodymium-neodymium permanent magnet submersible pump motor special rotor comprises a central iron plate (4) and a rotor outer sleeve (9), wherein the central iron plate (4) is inserted in parallel in the rotor outer sleeve (9), a lower half shaft (3) is installed at one end of the central iron plate (4), and an upper half shaft (2) is installed at the other end, the axes of the upper half shaft (2) and the lower half shaft (3) are on the same straight line, and the upper half shaft (2) and the lower half shaft (3) are symmetrical with respect to the central iron plate (4), the upper half shaft (2) and the lower half shaft (3) are connected to the central iron plate (4) via a groove, and half-moon-shaped magnetic rings are glued on the upper and lower sides of the central iron plate (4). The outer wall of the half-moon-shaped magnetic material (5) is in close contact with the inner wall of the rotor outer shell (9); the half-moon-shaped magnetic material (5) is a half-moon-shaped block formed by sintering a mixture of praseodymium, neodymium, iron and boron, and is branded N52; key grooves (10) are correspondingly provided on one side of the central iron plate (4) and the inner wall of the rotor outer shell (9); the central iron plate (4) and the rotor outer shell (9) are locked by embedding a key bar (6) in the key groove (10); annular silicon steel sheets (1) are installed at the two end ports of the rotor outer shell (9); key grooves (10) are correspondingly provided on the inner side of the silicon steel sheet (1) and the rotor outer shell (9); The silicon steel sheet (1) is provided with a plurality of pear-shaped flat-bottomed cast aluminum grooves (8) evenly spaced apart, and long ridge-shaped magnetic isolation bridges (7) are symmetrically provided on both sides of the silicon steel sheet (1), and the number of the pear-shaped flat-bottomed cast aluminum grooves (8) is specifically 16.

2. The method for preparing a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor according to claim 1, characterized in that: The half-moon-shaped magnetic material (5) and the middle iron plate (4) are both sprayed with epoxy structural adhesive.

3. The method for preparing a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor according to claim 1, characterized in that: The central iron plate (4) is specifically an iron plate made of electrical pure iron, with a brand of DT4E or DT4C.

4. According to the method for preparing a special rotor for a rare earth praseodymium-neodymium permanent magnet submersible pump motor as described in claim 1, the half-moon-shaped magnetic material (5) is bonded to both sides of the central iron plate (4), and the bonding material used is fast epoxy resin.

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