Variable-air-gap axial flux permanent magnet synchronous motor

Abstract

The invention belongs to the technical field of motors, and particularly discloses a variable-air-gap axial flux permanent magnet synchronous motor which comprises a machine shell, a stator module, a rotor module and an adjusting module. The rotor module comprises a rotating shaft, a rotor support and magnetic steel arranged on the rotor support, and the rotor support is fixedly arranged on the rotating shaft in a sleeving mode. The two stator modules are arranged on the two sides of the rotor support respectively. Each stator module comprises a stator and a stator support. The stator module and the rotor module are arranged in the casing, and the casing is provided with a through hole for a rotating shaft of the rotor module to pass through, so that one end of the rotating shaft of the rotor module extends out of the casing; and the adjusting module is used for synchronously adjusting the axial distance between the two stator modules and the rotor module so as to adjust air gaps on two sides of the rotor module. The size of air gaps on two sides of the rotor can be adjusted during assembly, so that the balance of the air gaps on the two sides is ensured, the noise of the motor is reduced, the size of the air gaps on the two sides can be effectively adjusted during operation, the efficiency of the motor is improved, and the constant-power rotating speed range of the motor is greatly widened.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors and relates to a permanent magnet synchronous motor, in particular to a variable air gap axial flux permanent magnet synchronous motor. Background Art

[0002] Permanent magnet synchronous motors are composed of components such as stators, rotors and end covers. They have the advantages of simple structure, small size, light weight and high efficiency. They are widely used in industry, agriculture, transportation, national defense, commercial and household appliances, medical equipment, aerospace and other fields.

[0003] Permanent magnet synchronous motors (PMSMs) include axial-flux PMSMs and radial-flux PMSMs. In axial-flux PMSMs, which utilize a dual-stator, single-rotor structure, the magnets are fixed within the rotor disk, leaving the magnets exposed between the air gaps on both sides. This makes it nearly impossible to use stator D-axis current for field weakening, limiting the motor's speed expansion capability. Furthermore, existing axial-flux PMSMs often exhibit axial assembly deviations during assembly, resulting in an unbalanced air gap between the two sides of the rotor. This, in turn, creates an unbalanced axial force on the rotor during rotation, leading to higher motor noise. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a variable air gap axial flux permanent magnet synchronous motor. The present invention can adjust the size of the air gap on both sides of the rotor during assembly, thereby ensuring the balance of the air gap on both sides and reducing motor noise. At the same time, it can also effectively adjust the size of the air gap on both sides during operation to improve motor efficiency.

[0005] The technical solution of the present invention is achieved as follows: A variable air gap axial magnetic flux permanent magnet synchronous motor comprises a casing, a stator module, a rotor module and an adjustment module.

[0006] The rotor module includes a rotating shaft, a rotor bracket and a magnet arranged on the rotor bracket. The rotor bracket is sleeved and fixed on the rotating shaft.

[0007] There are two stator modules, which are respectively arranged on both sides of the rotor support. The stator module includes a stator and a stator support.

[0008] The stator module and the rotor module are arranged in a casing, and a through hole is provided on the casing for the rotation shaft of the rotor module to pass through, so that one end of the rotation shaft of the rotor module extends out of the casing; the adjustment module is used to synchronously adjust the axial distance between the two stator modules and the rotor module, thereby adjusting the air gap on both sides of the rotor module.

[0009] Furthermore, the adjustment module includes a rotating gear and an adjustment mechanism, the central axis of the rotating gear intersects with the rotating shaft vertically, the adjustment mechanism includes an adjusting motor, a worm gear and a Hall position detector, the adjusting motor and the worm gear are arranged in a shell, the shell is arranged outside the casing, the output shaft of the adjusting motor is connected to one end of the worm gear, the other end of the worm gear extends out of the shell and extends into the casing, the rotating gear is arranged on the other end of the worm gear, and the Hall position detector is arranged on the worm gear close to the rotating gear side.

[0010] Racks are provided on the outer circumference of the two stator brackets. The two racks are parallel to each other and arranged along the axial direction of the rotating shaft. The two racks are located on both sides of the rotating gear and are engaged with the rotating gear. It is convenient to drive the rotating gear to rotate by adjusting the forward or reverse rotation of the motor to drive the two racks closer or farther away, thereby driving the two stator modules to move axially, and then synchronously adjust the axial distance between the two stator modules and the rotor module.

[0011] Furthermore, a number of sliders are evenly distributed on the outer circumference of the stator brackets of the two stator modules, and sliding grooves corresponding to the sliders are provided on the inner walls of the casings corresponding to the two stator modules. The sliders are arranged in the sliding grooves to facilitate the stator modules to maintain axial movement.

[0012] Furthermore, the shell is provided with two guide bars near the casing side, the two guide bars are coaxially spaced apart, and a guide groove cooperating with the two guide bars is provided on the outer wall of the casing. The two guide bars of the shell are clamped in the two guide grooves and can move axially along the guide grooves. At the same time, a strip hole is provided on the casing between the two guide grooves for the worm gear to move axially along the rotating shaft.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. The adjustment module of the present invention can synchronously adjust the axial distance between the two stator modules and the rotor module, so that the air gap on both sides of the rotor module remains balanced with high adjustment accuracy. At the same time, the adjustment module of the present invention can adjust the air gap according to different actual working conditions, increase the air gap at high speed to achieve weak magnetic speed expansion, greatly improve the constant power speed range, reduce the air gap at high torque to increase torque, and increase the air gap at low torque to improve efficiency.

[0014] 2. The present invention can drive the stator modules on both sides to move in the same direction in the casing by adjusting the axial position of the module during motor assembly, thereby changing the size of the air gap on both sides of the rotor, adjusting the symmetry of the air gap on both sides, reducing the axial magnetic unbalance force, and thus reducing noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 -Schematic diagram of the overall structure of the present invention.

[0016] Figure 2 -Schematic diagram of the explosion structure of the present invention.

[0017] Figure 3 -Schematic diagram of the structure of the regulation module.

[0018] Figure 4 -Schematic diagram of the casing structure.

[0019] Figure 5 -Schematic diagram of the stator module structure.

[0020] Figure 6 -Schematic diagram of the rotor module structure.

[0021] Figure 7 -Power characteristic curves of the motor of the present invention and the permanent magnet synchronous motor.

[0022] Among them: 1. Adjustment module; 1-1. Housing; 1-2. Rotating gear; 1-3-Guide bar; 2. Casing; 2-1. Casing unit; 2-2. Slide groove; 2-3-Guide groove; 3. Stator module; 3-1. Stator; 3-2. Stator bracket; 3-3. Slider; 3-4. Rack; 4. Rotor module; 4-1. Rotor bracket; 4-2. Bearing; 4-3. Rotating shaft; 4-4. Magnet. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] See also Figures 1 to 5 A variable air gap axial flux permanent magnet synchronous motor includes a casing 2, a stator module 3, a rotor module 4 and an adjustment module 1.

[0025] The rotor module 4 includes a rotating shaft 4-3, a bearing 4-2, a rotor bracket 4-1 and a magnetic steel 4-4 arranged on the rotor bracket 4-1. The rotor bracket 4-1 is sleeved and fixed on the rotating shaft 4-3.

[0026] There are two stator modules 3, which are respectively arranged on both sides of the rotor bracket 4-1. The stator module 3 includes a stator 3-1 and a stator bracket 3-2.

[0027] The stator module 3 and the rotor module 4 are arranged in the casing 2, and the casing 2 is provided with a through hole for the rotating shaft 4-3 of the rotor module 4 to pass through, so that one end of the rotating shaft 4-3 of the rotor module 4 extends out of the casing 2; the adjustment module 1 is used to synchronously adjust the axial distance between the two stator modules 3 and the rotor module 4, thereby adjusting the air gap on both sides of the rotor module 4.

[0028] The adjustment module here can synchronously adjust the axial distance between the two stator modules and the rotor module. In this way, when applied, synchronous adjustment can be performed according to different actual working conditions to ensure the consistency of the air gap on both sides of the rotor module with good adjustment accuracy.

[0029] In specific implementation, the adjustment module 1 includes a rotating gear 1-2 and an adjustment mechanism, the central axis of the rotating gear 1-2 intersects vertically with the rotating shaft 4-3, and the adjustment mechanism includes an adjustment motor, a worm gear and a Hall position detector. The adjustment motor and the worm gear are arranged in a shell 1-1, and the shell 1-1 is arranged outside the casing. The output shaft of the adjustment motor is connected to one end of the worm gear, and the other end of the worm gear extends out of the shell 1-1 and extends into the casing 1. The rotating gear 1-2 is arranged on the other end of the worm gear, and the Hall position detector is arranged on the worm gear close to the side of the rotating gear 1-2.

[0030] Racks 3-4 are respectively provided on the outer circumference of the two stator brackets 3-2. The two racks 3-4 are parallel to each other and arranged along the axial direction of the rotating shaft. The two racks 3-4 are located on both sides of the rotating gear 1-2 and are engaged with the rotating gear 1-2. It is convenient to drive the rotating gear 1-2 to rotate by adjusting the forward or reverse rotation of the motor, so as to drive the two racks 3-4 to move closer or farther away, thereby driving the two stator modules 3 to move axially, and then synchronously adjusting the axial distance between the two stator modules 3 and the rotor module 4.

[0031] In specific applications, the regulating motor and the Hall position detector are both connected to the power supply and the control unit. When the motor needs to adjust the air gap, the regulating motor in the regulating module 1 drives the worm gear to rotate the rotating gear 1-2, and the Hall sensor detects the rotation angle of the rotating gear. The rotating gear 1-2 drives the rack 3-4 to move the stator modules 3 on both sides in the opposite direction. The rotating gear 1-2 rotates clockwise to reduce the air gap, and rotates counterclockwise to increase the air gap. The air gap size can be accurately adjusted according to different actual working conditions. The air gap is increased at high speed to expand the weak magnetic speed, which greatly improves the constant power speed range. The air gap is reduced at high torque to increase the torque, and the air gap is increased at low torque to improve efficiency.

[0032] This motor uses the highest efficiency control algorithm with id=0. The electromagnetic loss of the motor is divided into copper loss and iron loss. When the motor operating conditions are determined, the current and air gap can be reduced to reduce copper loss and increase iron loss, and vice versa, thereby adjusting the loss ratio to achieve the highest efficiency. Under different operating conditions, the motor is calibrated to adjust the current and air gap size combination to select the most efficient combination. In specific implementation, a number of sliders 3-3 are evenly distributed on the outer circumference of the stator bracket 3-2 of the two stator modules 3, and a slide groove 2-2 corresponding to the slider 3-3 is provided on the inner wall of the casing 2 corresponding to the two stator modules 3. The slider 3-3 is arranged in the slide groove 2-2 to facilitate guiding the stator module 3 during the movement of the stator module 3, so that the stator module 3 always maintains axial movement.

[0033] In a specific implementation, the shell 1-1 is provided with two guide bars 1-3 near the side of the casing 2, and the two guide bars 1-3 are coaxially spaced apart. A guide groove 2-3 cooperating with the two guide bars 1-3 is provided on the outer wall of the casing 2. The two guide bars 1-3 of the shell 1-1 are clamped in the two guide grooves 2-3 and can move axially along the guide grooves 2-3. At the same time, a strip hole is provided on the casing 1 between the two guide grooves 2-3 for the worm gear to move axially along the rotating shaft.

[0034] In this way, during assembly, before the adjustment module is assembled, the air gap on both sides of the rotor module is the smallest (sucked by the rotor), but the air gaps between the two are not the same due to assembly errors, and the accuracy is not high. Then the adjustment module is assembled on the casing, and then the rotor is rotated to detect the size of the back electromotive force of the stators on both sides, and then the adjustment module is moved in slot 2-3. At this time, the gear is self-locked by the worm gear and cannot rotate, so that the two stators move axially in the same direction in the casing until the back electromotive force is consistent, which means that the air gaps on both sides of the rotor are balanced, thereby effectively reducing the motor noise.

[0035] As shown in the figure, the housing 2 in this embodiment is composed of two housing units 2-1. The two housing units are arranged facing each other, and sliding grooves corresponding to the sliders on the two stator modules are respectively arranged on the inner side walls of the two housing units.

[0036] The power characteristic curves of the motor of the present invention and the permanent magnet synchronous motor at different speeds are as follows: Figure 7 As shown in the figure, it can be seen that after the inflection point in the full speed range, the power of the permanent magnet synchronous motor gradually decreases, while the power of the motor of the present invention can remain stable within a wider speed range.

[0037] Finally, it should be noted that the above embodiments of the present invention are merely examples for illustrating the present invention and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations and modifications can be made based on the above description. It is not possible to enumerate all embodiments here. Any obvious variations or modifications arising from the technical solution of the present invention remain within the scope of protection of the present invention.

Claims

1. A variable air gap axial flux permanent magnet synchronous motor, characterized in that: It includes a housing, a stator module, a rotor module and a regulating module; The rotor module comprises a rotating shaft, a rotor bracket and a magnetic steel arranged on the rotor bracket, and the rotor bracket is sleeved and fixed on the rotating shaft; There are two stator modules, which are respectively arranged on both sides of the rotor support, and the stator module includes a stator and a stator support; The stator module and the rotor module are arranged in a casing, and a through hole is provided on the casing for the rotation shaft of the rotor module to pass through, so that one end of the rotation shaft of the rotor module extends out of the casing; the adjustment module is used to synchronously adjust the axial distance between the two stator modules and the rotor module, thereby adjusting the air gap on both sides of the rotor module.

2. A variable air gap axial flux permanent magnet synchronous motor according to claim 1, characterized in that: The regulating module includes a rotating gear and an regulating mechanism, wherein the central axis of the rotating gear intersects the rotating shaft vertically, and the regulating mechanism includes an regulating motor, a worm gear and a Hall position detector, wherein the regulating motor and the worm gear are arranged in a housing, and the housing is arranged outside the casing, and the output shaft of the regulating motor is connected to one end of the worm gear, and the other end of the worm gear extends out of the housing and into the casing, and the rotating gear is arranged on the other end of the worm gear, and the Hall position detector is arranged on the worm gear close to the rotating gear side; Racks are respectively provided on the outer circumference of the two stator brackets. The two racks are parallel to each other and arranged along the axial direction of the rotating shaft. The two racks are located on both sides of the rotating gear and are meshed with the rotating gear. It is convenient to drive the rotating gear to rotate by adjusting the forward or reverse rotation of the motor to drive the two racks to move closer or farther, thereby driving the two stator modules to move axially, and then synchronously adjusting the axial distance between the two stator modules and the rotor module.

3. A variable air gap axial flux permanent magnet synchronous motor according to claim 1 or 2, characterized in that: A number of sliders are evenly distributed on the outer circumference of the stator brackets of the two stator modules, and sliding grooves corresponding to the sliders are provided on the inner walls of the casings corresponding to the two stator modules. The sliders are arranged in the sliding grooves to facilitate the stator modules to maintain axial movement.

4. The variable air gap axial flux permanent magnet synchronous motor according to claim 2, characterized in that: The shell is provided with two guide strips near the casing side, the two guide strips are coaxially arranged at intervals, and the outer wall of the casing is provided with guide grooves matching the two guide strips. The two guide strips of the shell are clamped in the two guide grooves and can move axially along the guide grooves. At the same time, a strip hole is provided on the casing between the two guide grooves for the worm gear to move axially along the rotating shaft.

Images