CN111313644B

CN111313644B - Motor rotor structure and permanent magnet synchronous motor

Info

Publication number: CN111313644B
Application number: CN202010151875.7A
Authority: CN
Inventors: 李卓青; 黄振雄; 常俊国; 余佳龙
Original assignee: FUZHOU WONDER ELECTRIC CO LTD
Current assignee: Fuzhou Kaimeiyi Intelligent Equipment Manufacturing Co ltd
Priority date: 2020-03-06
Filing date: 2020-03-06
Publication date: 2021-04-27
Anticipated expiration: 2040-03-06
Also published as: CN111313644A

Abstract

The invention discloses a motor rotor structure and a permanent magnet synchronous motor, which can automatically adjust a magnetic field shielding block according to the rotating speed of a rotor, change a magnetic flux path through the position change of the magnetic field shielding block, and achieve the purpose of automatically reducing the permanent magnet magnetic flux along with the increase of the rotating speed, thereby improving the highest operating speed of the motor on the premise of unchanging power supply voltage; for the same motor, the effective excitation magnetic field strength is strong at low speed, so that the torque output capacity at low speed is ensured; at high speed, the effective excitation magnetic field is weakened, the highest running speed of the permanent magnet synchronous motor is improved, and the magnetic field shielding block changes the excitation size through the centrifugal action of the magnetic field shielding block, so that the rotor does not generate a deflection phenomenon.

Description

Motor rotor structure and permanent magnet synchronous motor

Technical Field

The invention relates to the technical field of motors, in particular to a motor rotor structure and a permanent magnet synchronous motor.

Background

The permanent magnet synchronous motor is one kind of synchronous motor, and its exciting magnetic field is produced by permanent magnet, so that it has the advantages of high power density, high efficiency and wide speed regulating range, etc.

Unlike an electrically excited synchronous motor, a permanent magnet synchronous motor generates an excitation magnetic field by a permanent magnet, and thus the magnetic field strength is generally constant. According to the basic electromagnetic relation of the permanent magnet synchronous motor, the rotating counter potential of the motor is increased along with the increase of the rotating speed, when the motor runs at high speed, the rotating counter potential approaches to the power supply voltage, the current regulator is saturated, the torque output performance of the motor is rapidly deteriorated, and the further increase of the rotating speed of the motor is limited.

The flux weakening control technology of the permanent magnet synchronous motor can solve the problems that the air gap magnetic field intensity of the motor is controlled to be correspondingly reduced along with the increase of the rotating speed of the motor, so that the increasing speed of the rotating back electromotive force is reduced. Therefore, the maximum running speed of the motor is improved under the condition that the power supply voltage is not changed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a motor with an effective excitation magnetic flux capable of being dynamically adjusted along with the rotating speed.

In order to achieve the purpose, the invention provides the following technical scheme:

a motor rotor structure comprises a rotor core and a rotating shaft, wherein a front fixing disc is arranged at the front end of the rotor core, a rear fixing disc is arranged at the rear end of the rotor core, a plurality of magnetic poles are uniformly fixed on the circumferential surface of the rotor core at equal intervals along the circumferential direction of the rotor core, a movable magnetic shielding block is arranged between every two adjacent magnetic poles, a guide mechanism used for guiding the magnetic shielding block to move back and forth along the axial direction of a rotor is further arranged between every two adjacent magnetic poles, a first pull rope is arranged in front of the magnetic shielding block along the axial direction of the rotor core and is a telescopic elastic rope, the front end of the first pull rope is relatively fixed with the front fixing disc, the rear end of the first pull rope is fixedly connected with the front part of the magnetic shielding block, a second pull rope is arranged behind the magnetic shielding block, a plurality of rope passing holes penetrating through a disc body are formed in the rear fixing disc, a plurality of sliding grooves are, the length direction of the sliding grooves is the radial direction of the rear fixing disc, reverse extension lines of connecting lines of the rope passing holes and the axis of the rotating shaft are symmetrical lines of the sliding grooves, sliding blocks are connected in the sliding grooves in a sliding mode, the front ends of the second pull ropes are fixedly connected with the rear portions of the magnetic shielding blocks, and the rear ends of the second pull ropes penetrate through the rope passing holes and are fixedly connected with the sliding blocks in the sliding grooves; the guide mechanism comprises a pair of guide rods arranged between adjacent magnetic poles, the guide rods are arranged along the axial direction of the rotor, the front ends of the guide rods are fixedly connected with the front fixed disk, the rear ends of the guide rods are fixedly connected with the rear fixed disk, the guide rods penetrate through the magnetic shielding blocks, and the magnetic shielding blocks can freely slide along the guide rods; a movable adjusting ring is further arranged in front of the magnetic pole and behind the front fixing disc, the adjusting ring is sleeved outside the rotor core and is arranged concentrically with the rotor core, a through hole is formed in the adjusting ring, the guide rod penetrates through the through hole, a plurality of first threaded holes are further uniformly formed in the adjusting ring along the circumferential direction of the adjusting ring, adjusting bolts are arranged on the front fixing disc corresponding to the first threaded holes, the front ends of the adjusting bolts are rotatably connected with the front fixing disc, the rear ends of the adjusting bolts are in threaded connection with the first threaded holes, and the front ends of the first pull ropes are fixedly connected with the adjusting ring; a plurality of inserting grooves which are arranged at equal intervals are formed in the sliding block along the length direction of the sliding block, inserting blocks which can be inserted and pulled are arranged in the inserting grooves, and the rear end of the second pull rope is fixedly connected with the inserting blocks.

As a preferable scheme: the diameter of back fixed disk is greater than the diameter of preceding fixed disk, just is located the limiting plate that is fixed with the V-arrangement between two adjacent magnetic poles at rotor core's rear end, the middle part of limiting plate is sunken to rotor core's inboard, and the contained angle between two adjacent magnetic poles is equallyd divide equally to the reverse extension line of the axle center line of rope hole and pivot is crossed to each, cross the rope hole and be less than the distance of magnetic shielding piece apart from the pivot axle center apart from the distance of pivot axle center, the middle part of second stay cord compresses tightly with the middle part of limiting plate.

As a preferable scheme: and the surfaces of the limiting plates and the inner walls of the rope passing holes are provided with wear-resistant and scratch-resistant layers.

As a preferable scheme: lubricating grease is smeared in the sliding groove.

A permanent magnet synchronous machine comprising a rotor structure of an electric machine according to any one of claims 1-7, characterized in that: the motor also comprises a shell and a stator structure, wherein the rotor structure is arranged in the shell.

As a preferable scheme: the rear end of the shell is provided with a containing part for containing the second fixing disc, the rear part of the containing part is of an open structure, a rear end cover is arranged behind the containing part, a plurality of second threaded holes are formed in the rear end face of the containing part along the circumferential direction of the containing part, hole positions are formed in the rear end cover corresponding to the second threaded holes, locking bolts penetrate through the hole positions, and the locking bolts are in threaded connection with the second threaded holes.

As a preferable scheme: the front end of shell and the place ahead that is located preceding fixed disk still seted up a plurality of openings along the circumference of shell, the front end of shell still is provided with split type safety cover, the opening that the safety cover is used for covering the shell front end and safety cover are the bowl form, the through-hole that supplies the pivot to pass is seted up at the center of safety cover, third screw hole has been seted up to the lateral part of safety cover, third screw hole female connection has clamp bolt.

Compared with the prior art, the invention has the advantages that: the invention can automatically adjust the magnetic field shielding block according to the rotating speed of the rotor, and change the magnetic flux path through the position change of the magnetic field shielding block, thereby achieving the purpose of automatically reducing the permanent magnetic flux along with the increase of the rotating speed, and further improving the highest operating speed of the motor on the premise of unchanging the power supply voltage; for the same motor, the effective excitation magnetic field strength is strong at low speed, so that the torque output capacity at low speed is ensured; at high speed, the effective excitation magnetic field is weakened, the highest running speed of the permanent magnet synchronous motor is improved, and the magnetic field shielding block changes the excitation size through the centrifugal action of the magnetic field shielding block, so that the rotor does not generate a deflection phenomenon.

Drawings

FIG. 1 is a first view of a rotor structure according to a first embodiment;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is an enlarged view of portion B of FIG. 1;

FIG. 4 is a second view of the rotor structure according to the first embodiment;

FIG. 5 is an enlarged view of the portion C of FIG. 4;

FIG. 6 is a schematic structural view of a synchronous swimming pool motor according to the second embodiment;

fig. 7 is a schematic structural view of the protective cover in the second embodiment.

Reference number 1, rotor core; 2. a front fixed disk; 3. a rear fixing disc; 4. a rotating shaft; 5. a magnetic pole; 6. a magnetic shielding block; 7. a guide bar; 8. a first pull cord; 9. an adjusting ring; 10. perforating; 11. a first threaded hole; 12. adjusting the bolt; 13. a limiting ring; 14. rope passing holes; 15. a second pull cord; 16. a limiting plate; 17. a chute; 18. a slider; 19. a guide rail; 20. a card slot; 21. inserting grooves; 22. an insertion block; 23. a housing; 24. a base; 25. a receptacle portion; 26. a rear end cap; 27. a second threaded hole; 28. a locking bolt; 29. an opening; 30. a protective cover; 31. a through hole; 32. a third threaded hole; 33. and pressing the bolt.

Detailed Description

The front and the rear are both referred to herein as the orientation of the rotating shaft 4, the end of the rotating shaft 4 connected to the external power transmission mechanism is the front end of the rotating shaft 4, and the end of the rotating shaft 4 not connected to the external power transmission mechanism is the rear end of the rotating shaft 4.

The first embodiment is as follows:

referring to fig. 1, a rotor structure of an electric motor comprises a rotor core 1 and a rotating shaft 4, wherein a front fixed disk 2 is arranged at the front end of the rotor core 1, a rear fixed disk 3 is arranged at the rear end of the rotor core 1, the diameter of the rear fixed disk 3 is larger than that of the front fixed disk 2, a plurality of magnetic poles 5 are uniformly fixed on the circumferential surface of the rotor core 1 along the circumferential direction at equal intervals, a movable magnetic shielding block 6 is arranged between two adjacent magnetic poles 5, the magnetic shielding block 6 can move back and forth along the axial direction of a rotor, a first pull rope 8 is arranged in front of the magnetic shielding block 6 along the axial direction of the rotor core 1, the first pull rope 8 is a telescopic elastic rope, the front end of the first pull rope 8 is fixed relative to the front fixed disk 2, the rear end of the first pull rope 8 is fixedly connected to the front part of the magnetic shielding block 6, a second pull rope 15 is arranged behind the magnetic shielding block 6, a V-shaped limit plate 16 is, the middle part of the limiting plate 16 is sunken towards the inner side of the rotor core 1, a plurality of rope passing holes 14 penetrating through the disc body are formed in the rear fixing disc 3, the included angle between two adjacent magnetic poles 5 is divided equally by the reverse extension line of the axis connecting line of each rope passing hole 14 and the rotating shaft 4, and the distance between the rope passing hole 14 and the axis of the rotating shaft 4 is smaller than the distance between the magnetic shielding block 6 and the axis of the rotating shaft 4.

Referring to fig. 4 and 5, a plurality of sliding grooves 17 are formed in the rear surface of the rear fixed disk 3, the length direction of each sliding groove 17 is the radial direction of the rear fixed disk 3, the sliding grooves 17 correspond to the rope passing holes 14 one by one, the reverse extension line of the connecting line of the rope passing holes 14 and the axis of the rotating shaft 4 is the symmetry line of the sliding groove 17, a sliding block 18 is connected in each sliding groove 17 in a sliding manner, and the sliding block 18 can freely slide back and forth along the length direction of the sliding groove 17.

The front end of the second pull rope 15 is fixedly connected with the rear part of the magnetic shielding block 6, the middle part of the second pull rope 15 is tightly pressed with the middle part of the limiting plate 16, and the rear end of the second pull rope 15 passes through the rear fixing disc 3 from the rope passing hole 14 and is fixedly connected with the sliding blocks 18 in the sliding grooves 17. The front section of the second rope 15 is coaxial with the first rope 8.

The working principle of the motor rotor is as follows: when the permanent magnet synchronous motor formed by the motor rotor structure does not work, the first pull rope 8 is in a contraction state, the first pull rope 8 pulls the magnetic shielding block 6 to the front limit position, and the effective excitation magnetic flux between the magnetic poles 5 is maximum at the moment; after the motor is started, each sliding block 18 can generate centrifugal force when rotating along with the rotor, the centrifugal force drives the sliding block 18 to slide in the sliding groove 17 in the direction far away from the rotating shaft 4, the sliding block 18 drives the second pull rope 15 to drive the rear end of the rotor iron core 1 behind the magnetic shielding block 6 to move, namely, the rear end is inserted between two adjacent magnetic poles 5, the magnetic leakage flux between the magnetic poles 5 is increased, and the effective excitation flux is reduced; when the rotating speed of the motor is increased, the centrifugal force of the sliding block 18 is increased, the sliding block 18 pulls the magnetic shielding block 6 to continuously move backwards through the second pull rope 15, the leakage magnetic flux between the magnetic poles 5 is further increased, and the effective excitation magnetic flux is reduced; when the rotating speed of the motor is reduced, the centrifugal force of the sliding block 18 is weakened, the elastic force of the first pull rope 8 drives the magnetic shield to move forwards, the leakage magnetic flux between the magnetic poles 5 is reduced, and the effective excitation magnetic flux is increased. The rule that the excitation magnetic flux changes along with the rotating speed meets the requirement of motor speed regulation.

In order to ensure smooth sliding of the slider 18, grease is applied to the inside of the sliding groove 17.

In other embodiments, the diameter of the rear fixed disk 3 can be designed to be larger, the distance between the rope passing hole 14 and the axis of the rotating shaft 4 is designed to be the same as the distance between the magnetic shielding block 6 and the axis of the rotating shaft 4, and the distance between the sliding groove 17 and the axis of the rotating shaft 4 is increased at the same time, so that the rear end of the second pull rope 15 can directly pass through the rope passing hole 14, and at this time, a limiting plate 16 is not required to be additionally arranged, so that the structure of the motor rotor can be simplified, but the volume of the motor rotor can be correspondingly increased.

Referring to fig. 1 and 2, in the present embodiment, a pair of guide rods 7 is further disposed between adjacent magnetic poles 5, the guide rods 7 are disposed along the axial direction of the rotor, the front ends of the guide rods 7 are fixedly connected to the front fixed disk 2, and the rear ends of the guide rods 7 are fixedly connected to the rear fixed disk 3. The guide bar 7 passes through the magnetic shield block 6, and the magnetic shield block 6 can freely slide along the guide bar 7. The stability of the magnetic shield block 6 when sliding can be increased by adding the guide bar 7, and the magnetic shield block 6 can be prevented from being radially thrown out due to centrifugal force. The guide rods 7 at the two ends of the limit plate 16 are fixedly connected.

Referring to fig. 1 and 2, a movable adjusting ring 9 is further disposed in front of the magnetic pole 5 and behind the front fixed disk 2, and the adjusting ring 9 is sleeved outside the rotor core 1 and is disposed concentrically with the rotor core 1. The adjusting ring 9 is provided with a through hole 10, the guide rod 7 penetrates through the through hole 10, the adjusting ring 9 is further uniformly provided with a plurality of first threaded holes 11 along the circumferential direction, adjusting bolts 12 are arranged on the front fixing disc 2 corresponding to the first threaded holes 11, the front ends of the adjusting bolts 12 are rotatably connected with the front fixing disc 2 (namely, hole positions are formed in the front fixing disc 2, the front ends of the adjusting bolts 12 penetrate through the hole positions, and limiting rings 13 are fixed on bolt bodies on the front side and the rear side of the hole positions, so that the adjusting bolts 12 can freely rotate and cannot relatively move with the front fixing disc 2, the structure is a common structure and is not repeated), the rear ends of the adjusting bolts 12 are in threaded connection with the first threaded holes 11, and when the adjusting bolts 12 are screwed, the adjusting ring 9 can be driven to move back and forth. The front end of the first pull rope 8 is fixedly connected with the adjusting ring 9. The tension degree of the first pull rope 8 can be adjusted by changing the front and rear positions of the adjusting ring 9 by screwing the adjusting bolt 12, namely the purpose of adjusting the initial tension of the first pull rope is achieved. Therefore, the requirement for dynamically adjusting the magnetic flux for different rotating speeds can be met, and the using freedom degree of the motor is higher.

Similarly, referring to fig. 4 and 5, the specific connection mode between the rear end of the second rope 15 and the slider 18 is: a plurality of inserting grooves 21 which are arranged at equal intervals are arranged on the sliding block 18 along the length direction of the sliding block, inserting blocks 22 which can be inserted and pulled are arranged in the inserting grooves 21, and the rear end of the second pull rope 15 is fixedly connected with the inserting blocks 22. By inserting the insertion block 22 into different insertion grooves 21, the initial position of the magnetic shield block 6 can be changed, which plays a role of adjusting the initial effective excitation flux of the magnetic pole 5 and also plays a role of adjusting the initial tension of the first pull rope 8. Make the motor can satisfy the more diversified user demand of user, its flexibility ratio that uses further improves.

Considering that the second pulling rope 15 will rub against the limiting plate 16 and the rope passing hole 14 during the movement of the magnetic shielding block 6, multiple times of rubbing may cause severe abrasion, which may affect the normal operation of the motor. In this embodiment, the surface of the limiting plate 16 and the inner wall of the rope passing hole 14 are both provided with wear-resistant and scratch-resistant layers, and are coated with lubricating grease, so as to avoid serious wear and ensure the service life of the motor rotor.

Example two:

referring to fig. 6, a permanent magnet synchronous motor includes a rotor structure according to the first embodiment, and further includes a housing 23 and a stator structure, a base 1 is fixed at the bottom of the housing 23, the rotor structure is installed inside the housing 23, a receiving portion 25 for receiving a second fixing disk is provided at the rear end of the housing 23, the diameter of the receiving portion 25 is larger than the diameter of the main body of the housing 23, an opening structure is provided at the rear portion of the receiving portion 25, a rear end cover 26 is provided behind the receiving portion 25, a plurality of second threaded holes 27 are provided on the rear end surface of the receiving portion 25 along the circumferential direction thereof, holes are provided at positions of the rear end cover 26 corresponding to the respective second threaded holes 27, locking bolts 28 are inserted into the holes, the locking bolts 28 are in threaded connection with the second threaded holes 27, the rear end cover 26 can be fixed with the housing 23 by the locking bolts 28, the rear end cover 26 can be removed after the locking, so that the rear surface of the rear fixing disk 3 is exposed to the outside, thereby facilitating the plugging of the plug-in block 22.

In addition, a plurality of openings 29 are further formed in the front end of the casing 23 and in front of the front fixing disk 2 along the circumferential direction of the casing 23, the openings 29 are used for allowing a wrench to enter the casing 23, a split type protective cover 30 is further arranged at the front end of the casing 23, the protective cover 30 is used for covering the openings 29 in the front end of the casing 23, the protective cover 30 is bowl-shaped, a through hole 31 for allowing the rotating shaft 4 to pass through is formed in the center of the protective cover 30, a third threaded hole 32 is formed in the side portion of the protective cover 30, and a compression bolt 33 is connected to the third threaded hole 32 in a threaded. After the protective cover 30 is covered at the front end of the shell 23, the pressing bolt 33 is screwed down, so that the end part of the pressing bolt is tightly abutted against the surface of the shell 23, the protective cover 30 can be fixed, and after the pressing bolt 33 is unscrewed, the protective cover 30 can be detached, so that a wrench or other tools can be conveniently stretched into the shell 23, and the adjusting bolt 12 can be screwed.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims

1. The utility model provides an electric motor rotor structure, includes rotor core, pivot, and rotor core's front end is provided with preceding fixed disk, and rotor core's rear end is provided with the after-fixing disk, is fixed with a plurality of magnetic poles, characterized by evenly along its circumference equidistant at rotor core's periphery: a movable magnetic shielding block is arranged between two adjacent magnetic poles, a guide mechanism used for guiding the magnetic shielding block to enable the magnetic shielding block to move back and forth along the axial direction of a rotor is also arranged between the two adjacent magnetic poles, a first pull rope is arranged in front of the magnetic shielding block along the axial direction of a rotor iron core and is a telescopic elastic rope, the front end of the first pull rope is relatively fixed with a front fixed disc, the rear end of the first pull rope is fixedly connected with the front part of the magnetic shielding block, a second pull rope is arranged behind the magnetic shielding block, a plurality of rope passing holes penetrating through a disc body are formed in the rear fixed disc, a plurality of sliding grooves are formed in the rear surface of the rear fixed disc, the length direction of each sliding groove is the radial direction of the rear fixed disc, the reverse extension line of the connecting line of the rope passing holes and a rotating shaft is a symmetrical line of the sliding grooves, sliding blocks are connected in each sliding groove in a sliding manner, and the front, the rear end of the second pull rope penetrates through the rope passing hole and is fixedly connected with the sliding blocks in the sliding grooves; the guide mechanism comprises a pair of guide rods arranged between adjacent magnetic poles, the guide rods are arranged along the axial direction of the rotor, the front ends of the guide rods are fixedly connected with the front fixed disk, the rear ends of the guide rods are fixedly connected with the rear fixed disk, the guide rods penetrate through the magnetic shielding blocks, and the magnetic shielding blocks can freely slide along the guide rods; a movable adjusting ring is further arranged in front of the magnetic pole and behind the front fixing disc, the adjusting ring is sleeved outside the rotor core and is arranged concentrically with the rotor core, a through hole is formed in the adjusting ring, the guide rod penetrates through the through hole, a plurality of first threaded holes are further uniformly formed in the adjusting ring along the circumferential direction of the adjusting ring, adjusting bolts are arranged on the front fixing disc corresponding to the first threaded holes, the front ends of the adjusting bolts are rotatably connected with the front fixing disc, the rear ends of the adjusting bolts are in threaded connection with the first threaded holes, and the front ends of the first pull ropes are fixedly connected with the adjusting ring; a plurality of inserting grooves which are arranged at equal intervals are formed in the sliding block along the length direction of the sliding block, inserting blocks which can be inserted and pulled are arranged in the inserting grooves, and the rear end of the second pull rope is fixedly connected with the inserting blocks.

2. The electric motor rotor structure of claim 1, wherein: the diameter of back fixed disk is greater than the diameter of preceding fixed disk, just is located the limiting plate that is fixed with the V-arrangement between two adjacent magnetic poles at rotor core's rear end, the middle part of limiting plate is sunken to rotor core's inboard, and the contained angle between two adjacent magnetic poles is equallyd divide equally to the reverse extension line of the axle center line of rope hole and pivot is crossed to each, cross the rope hole and be less than the distance of magnetic shielding piece apart from the pivot axle center apart from the distance of pivot axle center, the middle part of second stay cord compresses tightly with the middle part of limiting plate.

3. The electric motor rotor structure of claim 2, wherein: and the surfaces of the limiting plates and the inner walls of the rope passing holes are provided with wear-resistant and scratch-resistant layers.

4. The electric motor rotor structure of claim 1, wherein: lubricating grease is smeared in the sliding groove.

5. A permanent magnet synchronous machine comprising a rotor structure of an electric machine according to any one of claims 1-4, characterized in that: the motor also comprises a shell and a stator structure, wherein the rotor structure is arranged in the shell.

6. The permanent magnet synchronous motor of claim 5, wherein: the rear end of the shell is provided with a containing part for containing the second fixing disc, the rear part of the containing part is of an open structure, a rear end cover is arranged behind the containing part, a plurality of second threaded holes are formed in the rear end face of the containing part along the circumferential direction of the containing part, hole positions are formed in the rear end cover corresponding to the second threaded holes, locking bolts penetrate through the hole positions, and the locking bolts are in threaded connection with the second threaded holes.

7. The permanent magnet synchronous motor of claim 5, wherein: the front end of shell and the place ahead that is located preceding fixed disk still seted up a plurality of openings along the circumference of shell, the front end of shell still is provided with split type safety cover, the opening that the safety cover is used for covering the shell front end and safety cover are the bowl form, the through-hole that supplies the pivot to pass is seted up at the center of safety cover, third screw hole has been seted up to the lateral part of safety cover, third screw hole female connection has clamp bolt.