CN106877578A - An oil-cooled, low-consumption inner rotor permanent magnet motor - Google Patents

Abstract

An oil-cooled, low-consumption inner-rotor permanent magnet motor belongs to the field of motors. The purpose of the invention is to reduce oil friction loss, improve heat dissipation capacity, and further increase the power density of motors used in oil-filled environments. The invention includes a stator and a rotor. The stator includes a casing, a stator core, an insulating layer, an axial key, a plurality of stator coils, and two end covers; the rotor includes a rotor shaft, a rotor yoke, two bearings, and a plurality of magnets. . The feature of the present invention is that both sides of the inner arc surface of each magnetic steel are cut with inner angles; on the outer surface of the rotor composed of a plurality of magnetic steels, there are screw-in drainage grooves along the axial direction; on the inner circle of the rotor yoke The surface is provided with oblique flow grooves along the axial direction, and multiple oblique flow grooves are distributed symmetrically along the circumference; when the stator core is directly cast, multiple return holes should be left on the yoke, or a number of return holes should be left on its back. Multiple return slots provide channels for the oil to circulate inside the motor. The use of such motors in oil-filled high-temperature environments can increase power density and has great practical value.

Description

An oil-cooled, low-consumption inner rotor permanent magnet motor

technical field

The invention relates to an inner rotor permanent magnet motor, which belongs to the field of motors.

Background technique

In the design of permanent magnet motors, in order to reduce the harmonics of the air gap magnetic field, the design scheme of unequal air gaps is often used. The outer surface formed by the magnetic steel bonded to the rotor yoke is not a smooth cylindrical surface (as shown in the figure 15), but there is a bulge. In certain operating environments, motors running submerged in oil and filled with oil pose particular problems compared to motors running in air. First of all, when the rotor moves in the fluid, the non-smooth outer surface causes greater resistance, the oil friction loss of the motor increases, the efficiency decreases, and the power density of the entire system decreases. Secondly, the oil in the air gap of the existing oil-filled permanent magnet motor basically flows in the circumferential direction, and the axial flow is small. The heat transfer mainly depends on heat conduction, and the good heat conduction characteristics of the oil are not fully utilized.

Contents of the invention

The purpose of the present invention is to provide an oil-cooled, low-consumption inner-rotor permanent magnet motor, which can reduce oil friction loss, improve heat dissipation, and further increase the power density of the motor used in an oil-filled environment.

Realize above-mentioned object, the technical scheme that the present invention takes is as follows:

An oil-cooled, low-consumption internal rotor permanent magnet motor, which includes a stator and a rotor, the stator includes a casing, a stator core, an insulating layer, an axial key, a plurality of stator coils and two end covers; The rotor includes a rotor shaft, a rotor yoke, two bearings and a plurality of magnetic steels; the rotor yoke is fixed on the outer surface of the rotor shaft, and the outer surface of the rotor yoke is located on the same circumference and closely arranged in sequence. The two ends of the rotor shaft are rotatably connected to the two end covers through a bearing. The casing ring is set on the outside of the plurality of magnetic steels. The casing and the two end covers are detachably connected by screws. A stator core is set on the outer ring of the magnetic steel, and a radial gap is set between the stator core and the magnetic steel. The stator core is evenly distributed along the circumferential direction with a plurality of installations communicating with the inner surface of the stator core. slots, each of the installation slots is provided with an insulating layer on the inner surface, and each installation slot is provided with a stator coil, and the stator core and the casing are detachably and fixedly connected by axial keys;

Both sides of the inner arc surface of each magnetic steel are cut with inner angles (that is, the outer arc surface of the magnet steel is kept close to the air gap side, and the two corners of the inner arc surface of the magnet steel and the rotor yoke side are cut off. Because The complete outer arc surface of the magnetic steel is retained, and the outer surface of the rotor formed by splicing the magnetic steel is still a smooth cylindrical surface); on the outer circular surface composed of multiple magnetic steels, there is at least one precession drainage in the axial direction Slots; at least two oblique flow grooves are arranged in the axial direction on the inner surface of the rotor yoke, and all the oblique flow grooves are distributed symmetrically along the circumference; when the stator core is directly cast, the yoke of the stator core There are multiple return holes on the top, or multiple return grooves on the back to provide channels for the oil to circulate inside the motor, and each end cover is equipped with oil holes.

The beneficial effect of the present invention relative to prior art is:

1. What is used in the present invention is to cut the inner angle of the magnetic steel, that is, retain the outer arc surface of the magnetic steel and the air gap side, and cut off the two corners of the inner arc surface of the magnetic steel and the rotor yoke side. Because the complete outer arc surface of the magnetic steel is retained, the outer surface of the rotor formed by splicing the magnetic steel is still a smooth cylindrical surface. Compared with the permanent magnet motor designed with unequal air gaps, the invention reduces the resistance of the motor rotor when it rotates, reduces the oil friction loss, and improves the power density of the motor. In addition, the chamfered inner angle of the magnetic steel and the outer surface of the rotor yoke form multiple axial passages, which facilitate the rapid passage of oil inside the motor, increase the amount of oil entering the motor, speed up the heat conduction inside the motor, and improve the heat dissipation capacity. The schematic diagram of the air-gap magnetic field of the angle-cut magnet in the present invention and the traditional tile-shaped magnet (as shown in FIG. 16 ), after comparison, it can be found that the harmonics of the air-gap magnetic field generated by the angle-cut magnet are significantly reduced.

2. For rotors with a screw-in drainage groove structure (that is, left-handed or right-handed screw-in drainage grooves are processed on the outer surface of the rotor), when the rotor is placed upright on a horizontal plane, the screw-in drainage grooves rotate counterclockwise and rise to become left-handed. The spiral-in drainage groove; the spiral-in drainage groove rotates and rises clockwise, which is the right-handed spiral-in drainage groove. Wherein, the cross-sectional shape of the precession drainage groove may be rectangular, semicircular, triangular or trapezoidal. Designing the cross-section to the above shape allows the rotor to move the oil around it. The precession drainage groove is processed on the outer surface of the cylindrical structure formed by a plurality of magnetic steel arrangements. In addition, the number of screw-in drainage grooves can be increased according to specific design requirements. When the motor rotates, the precession drainage groove on the outer surface of the rotor will drive the nearby oil to move axially while moving in the circumferential direction, speeding up the heat conduction inside the motor, improving the heat dissipation capacity and increasing the power density of the motor.

3. A plurality of notches connected to the inner circle of the rotor punch are provided and distributed symmetrically along the circumference. During the lamination process, adjacent rotor punches are sequentially staggered by a certain angle to form a rotor yoke with oblique flow grooves. All inclined chutes are inclined in the same direction. During the operation of the motor, the oil injected from the oil hole can not only flow through the air gap, but also flow through the oblique flow groove of the rotor yoke; in addition, the oblique flow groove generates suction to the oil when it rotates with the rotor , to speed up the oil circulation inside the motor and improve the heat dissipation capacity.

4. When the stator core is cast directly, leave multiple return holes on the yoke, or leave multiple return grooves on the back to provide channels for the oil to circulate inside the motor. Stator core plus axial hole has only been used in air-cooled motors, the purpose is to increase the ventilation of the motor. Not used in oil-filled motors, the purpose of this measure in the present invention is to create channels for oil circulation.

Description of drawings

Fig. 1 is a main sectional view of an oil-cooled, low-consumption inner rotor permanent magnet motor of the present invention, and the stator windings involved in the motor are of a distributed structure;

Fig. 2 is the sectional view of the A-A section of Fig. 1;

Fig. 3 is a main sectional view of an oil-cooled, low-consumption inner rotor permanent magnet motor of the present invention, and the stator winding involved in the motor is a centralized structure;

Fig. 4 is the sectional view of the B-B section of Fig. 3;

Fig. 5 is a schematic structural view of the magnetic steel, wherein both sides of the inner arc surface of the magnetic steel are all cut inside angles, and the surface of the cut inside angles is a slope;

Fig. 6 is a schematic structural view of the magnetic steel, wherein both sides of the inner arc surface of the magnetic steel are all cut inside angles, and the surface of the inner angle cut is an outwardly convex arc surface;

Fig. 7 is a schematic structural view of the magnetic steel, in which both sides of the inner arc surface of the magnetic steel have internal angles cut, and the surface of the internal angle cut is an inwardly concave arc surface;

Fig. 8 is a structural schematic diagram of a magnetic steel, in which both sides of the inner arc surface of the magnetic steel are cut with inner corners, and the shape of the cut inner corners is V-shaped;

Fig. 9 is a structural schematic diagram of a magnetic steel with a screw-in drainage groove, and the screw-in drainage groove is a left-handed screw-in drainage groove;

Fig. 10 is a structural schematic diagram of a magnetic steel with a screw-in drainage groove, and the screw-in drainage groove is a right-handed screw-in drainage groove;

Fig. 11 is a schematic structural view of an oblique chute, wherein the oblique chute is a left-inclined chute;

Fig. 12 is a schematic structural view of an oblique chute, wherein the oblique chute is a right-sloping chute;

Fig. 13 is a schematic structural view of the stator core, leaving return holes in the yoke of the stator core;

Fig. 14 is a schematic structural view of the stator core, leaving a backflow groove at the back of the stator core;

Fig. 15 is a schematic structural diagram of the prior art;

Fig. 16 is a schematic diagram of the air gap magnetic field between the angle-cutting magnet and the traditional tile-shaped magnet in the present invention, wherein curve C is the air-gap flux density curve of the inside-angle-cutting magnet, and curve D is the gas density curve of the traditional tile-shaped magnet. Gap flux density curve.

Explanation of attached drawing numbers:

Rotor shaft 1, bearing 2, end cover 3, oil hole 3-1, casing 4, stator coil 5, stator core 6, return hole 6-1, return groove 6-2, magnetic steel 7, screw-in drainage Groove 7-1, rotor yoke 8, oblique flow groove 8-1, insulating layer 9, axial key 10, screw 11, chamfered inner angle 12, axial channel 13.

The technical solution of the present invention will be further described below in conjunction with the accompanying drawings, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered by the present invention. within the scope of protection.

detailed description

Specific Embodiment 1: As shown in Figures 1 to 14, this embodiment records an oil-cooled, low-consumption inner rotor permanent magnet motor, which includes a stator and a rotor, and the stator includes a casing 4, a stator iron core 6, insulating layer 9, axial key 10, multiple stator coils 5 and two end covers 3; the rotor includes a rotor shaft 1, a rotor yoke 8, two bearings 2 and multiple magnetic steels 7; The rotor yoke 8 described above is fixed on the outer surface of the rotor shaft 1, and the outer surface of the rotor yoke 8 is located on the same circumference, and a plurality of magnetic steels 7 are closely arranged in sequence, and the two ends of the rotor shaft 1 pass through a bearing 2 and The two end covers 3 are rotatably connected, the casing 4 rings are set on the outside of a plurality of magnetic steels 7, the casing 4 and the two end covers 3 are detachably fixedly connected by screws 11, and the outer rings of the plurality of magnetic steels 7 are fitted with The stator core 6 is provided with a radial gap between the stator core 6 and the magnetic steel 7, and the stator core 6 is evenly distributed along the circumferential direction with a plurality of installation grooves communicating with the inner surface of the stator core 6, The inner surface of each installation groove is provided with an insulating layer 9, and each installation groove is provided with a stator coil 5, and the stator core 6 and the casing 4 are detachably and fixedly connected by an axial key 10;

Both sides of the inner arc surface of each magnetic steel 7 are cut with an inner angle 12 (that is, the outer arc surface of the magnet steel 7 and the air gap side are kept, and the inner arc surface of the magnet steel 7 and the rotor yoke 8 side is cut off. The two corners. Because the complete outer arc surface of the magnetic steel 7 is retained, the outer surface of the rotor formed after the splicing of the magnetic steel 7 is still a smooth cylindrical surface); At least one screw-in drainage groove 7-1 is provided in the direction; at least two oblique flow grooves 8-1 are arranged in the axial direction on the inner surface of the rotor yoke 8, and all oblique flow grooves 8-1 are arranged along the circumference Symmetrical distribution; when the stator core 6 is directly casted, a plurality of return holes 6-1 are left on the yoke of the stator core 6, or a plurality of return grooves 6-2 are left on the back of the stator core 6 to provide oil in the motor. The circulation provides channels, and each end cover 3 is provided with an oil through hole 3-1.

Specific embodiment two: as shown in Figure 2 and Figure 4, this embodiment will further describe the specific embodiment one, the chamfered inner corners 12 of the plurality of magnetic steels 7 and the outer circular surface of the rotor yoke 8 form a plurality of axial Channel 13.

Specific embodiment three: as shown in Figure 9 and Figure 10, this embodiment will further explain the specific embodiment one, the described screw-in drainage groove 7-1 is a left-handed or right-handed screw-in drainage groove 7-1, so The setting principle of the left-handed or right-handed screw-in drainage groove 7-1 is: when the rotor is placed upright on a horizontal plane, the screw-in drainage groove 7-1 rotates and rises in the counterclockwise direction, which is the left-handed screw-in drainage groove 7-1. 1; The spiraling drainage groove 7-1 rotates and rises in the clockwise direction, which is the right-handed spiraling drainage groove 7-1, wherein the cross-sectional shape of the spiraling drainage groove 7-1 is rectangular, semicircular, triangular or trapezoidal.

Embodiment 4: As shown in Fig. 11 and Fig. 12, this embodiment will further explain Embodiment 1. The processing process of the oblique flow groove 8-1 is: several rotors forming the rotor yoke 8 A plurality of notches communicated with the inner circle and distributed symmetrically along the circumference are arranged on the punching sheet. During the lamination process, the adjacent rotor punching sheets are sequentially staggered at a certain angle to form a rotor yoke with at least two oblique flow grooves 8-1. 8. All inclined flow channels 8-1 have the same inclination direction, that is, they can be inclined to the left or to the right.

Claims (4)

1. An oil-cooled, low-consumption inner-rotor permanent magnet motor, which includes a stator and a rotor, and the stator includes a casing (4), a stator core (6), an insulating layer (9), and an axial key (10 ), a plurality of stator coils (5) and two end covers (3); the rotor includes a rotor shaft (1), a rotor yoke (8), two bearings (2) and a plurality of magnets (7) ; The rotor yoke (8) is fixed on the outer surface of the rotor shaft (1), and the outer surface of the rotor yoke (8) is located on the same circumference with a plurality of magnetic steels (7) closely arranged in turn, and the rotor shaft Both ends of (1) are rotatably connected to two end covers (3) through a bearing (2), and the casing (4) is ring-set on the outside of a plurality of magnetic steels (7), and the casing (4) and The two end covers (3) are detachably fixedly connected by screws (11), and the stator core (6) is set on the outer ring of a plurality of magnet steels (7), and the stator core (6) and the magnet steel (7) There is a radial gap between them, and the stator core (6) is evenly distributed along the circumferential direction with a plurality of installation grooves communicating with the inner surface of the stator iron core (6), and the inner surface of each installation groove is provided with Insulation layer (9), stator coil (5) is arranged in each installation slot, stator core (6) and casing (4) are detachably and fixedly connected by axial key (10); It is characterized in that the inner angles (12) are cut on both sides of the inner arc surface of each magnet steel (7) (that is, the outer arc surface of the magnet steel (7) and the air gap side are kept, and the magnet steel (7) is cut off. The two corners of the inner arc surface close to the side of the rotor yoke (8); Because the complete outer circular surface of the magnetic steel (7) is retained, the outer surface of the rotor formed by splicing the magnetic steel (7) is still a smooth cylindrical surface); on the outer circular surface composed of multiple magnetic steel (7) There is at least one screw-in drainage groove (7-1) along the axial direction; at least two oblique flow grooves (8-1) are arranged on the inner surface of the rotor yoke (8) along the axial direction, and all oblique The overflow slots (8-1) are symmetrically distributed along the circumference; when the stator core (6) is directly cast, a plurality of return holes (6-1) are left on the yoke of the stator core (6), or There are multiple return grooves (6-2) on the back to provide channels for the oil to circulate inside the motor. 2. An oil-cooled, low-consumption inner-rotor permanent magnet motor according to claim 1, characterized in that the cut inner corners (12) of the plurality of magnetic steels (7) are in contact with the rotor yoke (8) outer The circular surface forms a plurality of axial channels (13). 3. An oil-cooled, low-consumption inner rotor permanent magnet motor according to claim 1, characterized in that, the said precession drainage groove (7-1) is a left-handed or right-handed helical precession drainage groove (7-1) -1), the setting principle of the left-handed or right-handed screw-in drainage groove (7-1) is: when the rotor is placed upright on a horizontal plane, the screw-in drainage groove (7-1) rotates counterclockwise and rises. It is a left-handed screw-in drainage groove (7-1); the screw-in drainage groove (7-1) rotates clockwise and rises to become a right-handed screw-in drainage groove (7-1), wherein, the screw-in drainage groove ( 7-1) The cross-sectional shape is rectangular, semicircular, triangular or trapezoidal. 4. An oil-cooled, low-consumption inner-rotor permanent magnet motor according to claim 1, characterized in that, the processing process of the oblique trough (8-1) is: in forming the rotor yoke (8-1) ) on several rotor punches, which communicate with the inner circle and are distributed symmetrically along the circumference. During the stacking process, the adjacent rotor punches are staggered by a certain angle to form a structure with at least two oblique flow grooves (8 -1) For the rotor yoke (8), all oblique launders (8-1) have the same inclination direction.