Combined magnetic pole permanent magnet generator with asymmetric magnetic pole center structure

Abstract

The present invention provides a combined-pole permanent magnet generator with an asymmetric magnetic pole center structure, belonging to the technical field of automotive motors and electrical appliances. The generator comprises a front cover, a rear cover, a combined-pole permanent magnet rotor, a rotating shaft, and a stator. The combined-pole structure features a V-shaped permanent magnet at the north pole center and a semicircular permanent magnet at the south pole center. The asymmetric combined-pole structure prevents magnetic field concavity at the pole center, weakens air gap magnetic field harmonics, and reduces cogging torque. Furthermore, the arrangement of the combined permanent magnets improves rotor space utilization and increases the generator's power density.

Description

Technical Field

[0001] The invention provides a combined magnetic pole permanent magnet generator with an asymmetric magnetic pole center structure, belonging to the technical field of automobile motors and electrical appliances. Background Art

[0002] Permanent magnet generators for electric vehicles have the advantages of high power density, high efficiency, and the ability to output high-quality voltage. However, in order to save costs, the rotors currently used in permanent magnet generators for electric vehicles mostly adopt pure tangential and pure radial rotors, and most of them have a symmetrical magnetic pole structure. The air gap magnetic field of this type of permanent magnet generator is provided by a single tangential permanent magnet steel or radial permanent magnet steel. The magnetic pole center has poor magnetic concentration ability and low magnetic field strength. The sinusoidality of the air gap magnetic flux density curve is poor, and there is a large cogging torque, which affects the output performance of the motor. Therefore, it is very necessary to invent a combined magnetic pole permanent magnet generator with an asymmetric magnetic pole center structure that can fully utilize the internal space of the rotor, the main magnetic flux is provided by a combined permanent magnet steel, and the air gap magnetic field magnetic flux harmonics are weakened by adopting a combined magnetic pole structure with an asymmetric magnetic pole center structure, thereby reducing the cogging torque and improving the output performance. Summary of the Invention

[0003] The purpose of the present invention is to provide a combined magnetic pole permanent magnet generator with an asymmetric magnetic pole center structure, which can overcome the above-mentioned defects. The center of the N pole magnetic pole is a "V"-shaped permanent magnet steel, and the center of the S pole magnetic pole is a semicircular permanent magnet steel. The magnetic circuits of the N pole and S pole centers are asymmetric, which can effectively increase the air gap magnetic flux density, weaken the air gap magnetic field magnetic flux density harmonics, and reduce the cogging torque. The technical content is as follows:

[0004] A combined-type permanent magnet generator with an asymmetric magnetic pole center structure, consisting of a shaft, a rear end cover, a rotor core, a stator core, a first rectangular permanent magnet steel, a second rectangular permanent magnet steel, a tangential permanent magnet steel, a front end cover, and a semicircular permanent magnet steel, is characterized in that: the rotor is an asymmetric combined permanent magnet rotor;

[0005] An even number of first V-shaped permanent magnets, each consisting of two first rectangular permanent magnets, are arranged circumferentially near the outer circumference of the rotor core. The outer polarities of the first V-shaped permanent magnets are arranged with N and S poles alternating. The distance from the midpoint of a line connecting the inner ends of the two first rectangular permanent magnets forming the first V-shaped permanent magnets to the center of the rotor core is 2 / 3 of the radius of the outer circumference of the rotor core. The angle between the two first rectangular permanent magnets forming the first V-shaped permanent magnets is 80°. There is a 1.5 mm disconnected portion between the inner ends of the two first rectangular permanent magnets forming the first V-shaped permanent magnets. First arc-shaped magnetic isolation air gaps are provided at both inner and outer ends of the first rectangular permanent magnets. There is a 1.5 mm disconnected portion between the first arc-shaped magnetic isolation air gap and the outer circumference of the rotor core.

[0006] A second V-shaped permanent magnet steel consisting of two second rectangular permanent magnet steels is designed on the outer side of the first V-shaped permanent magnet steel with an N-pole polarity facing the outer circumference of the rotor core. The angle between the two second rectangular permanent magnet steels forming the second V-shaped permanent magnet steel is 90°. There is a 1.5mm disconnected portion between the inner ends of the two second rectangular permanent magnet steels forming the second V-shaped permanent magnet steel. A right-angled trapezoidal magnetic isolation air gap is provided at both inner and outer ends of the second rectangular permanent magnet steel. The height of the right-angled trapezoidal magnetic isolation air gap is connected to the short side of the second rectangular permanent magnet steel and the height of the right-angled trapezoidal magnetic isolation air gap is less than the length of the short side of the second rectangular permanent magnet steel. Both corners on the oblique waist side of the right-angled trapezoidal magnetic isolation air gap are rounded, and the outer end of the right-angled trapezoidal magnetic isolation air gap is 1.5mm away from the outer circumference of the rotor core.

[0007] A semicircular permanent magnet is designed on the outer side of the first "V"-shaped permanent magnet with an S-pole polarity facing the outer circumference of the rotor core. The center of the semicircular permanent magnet is on the symmetry line of the first "V"-shaped permanent magnet, and the outer end of the semicircular permanent magnet is 1.5 mm away from the outer circumference of the rotor.

[0008] A tangential permanent magnet is provided between every two adjacent first V-shaped permanent magnets. The polarity of the opposing surfaces of the two adjacent tangential permanent magnets is the same as the polarity of the first V-shaped permanent magnet between the two adjacent tangential permanent magnets facing the outer circumference of the rotor core. The distance from the midpoint of the inner end of the tangential permanent magnet to the center of the rotor is 1 / 2 of the rotor radius. A second arc-shaped magnetic isolation air gap is provided on the outer side of the tangential permanent magnet. There is a 1.5mm unconnected portion between the second arc-shaped magnetic isolation air gap and the outer circumference of the rotor. A "convex" shaped magnetic isolation air gap composed of a rectangular magnetic isolation air gap and a sector-shaped magnetic isolation air gap is provided on the inner side of the tangential permanent magnet steel. The outer side of the rectangular magnetic isolation air gap is connected to the short side of the inner end of the tangential permanent magnet steel and the width of the outer side of the rectangular magnetic isolation air gap is smaller than the width of the short side of the inner end of the tangential permanent magnet steel. The centers of the two arc sides of the sector-shaped magnetic isolation air gap are both located at the center of the rotor. The corners of the sector-shaped magnetic isolation air gap are all rounded, and there is a 1.5mm unconnected part between adjacent "convex" shaped magnetic isolation air gaps.

[0009] Working principle: The shaft of the permanent magnet generator rotates driven by the pulley, and the armature winding in the stator cuts the magnetic field generated by the permanent magnet steel of the rotor. According to the principle of electromagnetic induction, an induced electromotive force is generated in the armature winding, and current can be generated through the closed load circuit.

[0010] Compared with the prior art, the present invention has an asymmetric structure of the N-pole and S-pole magnetic pole centers. By rationally designing the magnetic circuit direction of the magnetic pole center, the magnetic flux density harmonics of the air gap magnetic field can be effectively weakened. The combined magnetic pole structure can avoid the phenomenon of concave air gap magnetic field center, increase the sinusoidality of the air gap magnetic flux density curve, increase the air gap magnetic flux density, and improve the utilization rate of the rotor internal space. In addition, a "convex"-shaped magnetic isolation air gap is provided inside the tangential permanent magnet steel, which can effectively reduce leakage flux and improve the output performance of the generator. The arrangement of the asymmetric magnetic poles can effectively reduce the cogging torque and improve the noise and vibration problems of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural diagram of an embodiment of the present invention;

[0012] Figure 2 yes Figure 1 Right side view of the permanent magnet rotor in the illustrated embodiment.

[0013] In the figure: 1, shaft 2, rear end cover 3, rotor core 4, armature winding 5, stator core 6, first rectangular permanent magnet steel 7, second rectangular permanent magnet steel 8, tangential permanent magnet steel 9, "convex" shaped magnetic isolation air gap 10, front end cover 11, fan 12, bearing 13, screw 14, pulley 15, semicircular permanent magnet steel 16, first arc-shaped magnetic isolation air gap 17, second arc-shaped magnetic isolation air gap 18, right-angled trapezoidal magnetic isolation air gap. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings:

[0015] A combined-type permanent magnet generator with an asymmetric magnetic pole center structure, consisting of a shaft 1, a rear end cover 2, a rotor core 3, a stator core 5, a first rectangular permanent magnet steel 6, a second rectangular permanent magnet steel 7, a tangential permanent magnet steel 8, a front end cover 10, and a semicircular permanent magnet steel 15, is characterized in that: the rotor is an asymmetric combined permanent magnet rotor;

[0016] An even number of first V-shaped permanent magnets, each consisting of two first rectangular permanent magnets 6, are arranged circumferentially near the outer circumference of the rotor core 3. The outer polarities of the first V-shaped permanent magnets are arranged with N and S poles at intervals. The distance from the midpoint of the line connecting the inner ends of the two first rectangular permanent magnets 6 forming the first V-shaped permanent magnet to the center of the rotor core 3 is 2 / 3 of the outer radius of the rotor core 3. The angle between the two first rectangular permanent magnets 6 forming the first V-shaped permanent magnet is 80°. There is a 1.5 mm disconnected portion between the inner ends of the two first rectangular permanent magnets 6 forming the first V-shaped permanent magnet. First arc-shaped magnetic isolation air gaps 16 are provided at both inner and outer ends of the first rectangular permanent magnets 6. There is a 1.5 mm disconnected portion between the first arc-shaped magnetic isolation air gap 16 and the outer circumference of the rotor core 3.

[0017] A second V-shaped permanent magnet steel consisting of two second rectangular permanent magnet steels 7 is designed on the outer side of the first V-shaped permanent magnet steel with a polarity of N toward the outer circumference of the rotor core 3. The angle between the two second rectangular permanent magnet steels 7 constituting the second V-shaped permanent magnet steel is 90°. There is a 1.5mm unconnected portion between the inner ends of the two second rectangular permanent magnet steels 7 constituting the second V-shaped permanent magnet steel. A right-angled trapezoidal magnetic isolation air gap 18 is provided at both inner and outer ends of the second rectangular permanent magnet steel 7. The height of the right-angled trapezoidal magnetic isolation air gap 18 is connected to the short side of the second rectangular permanent magnet steel 7 and the height of the right-angled trapezoidal magnetic isolation air gap 18 is less than the length of the short side of the second rectangular permanent magnet steel 7. Both corners on the oblique waist side of the right-angled trapezoidal magnetic isolation air gap 18 are rounded, and the outer end of the right-angled trapezoidal magnetic isolation air gap 18 is 1.5mm away from the outer circumference of the rotor core 3.

[0018] A semicircular permanent magnet 15 is designed on the outer side of the first "V"-shaped permanent magnet with the S-pole polarity facing the outer circumference of the rotor core 3. The center of the semicircular permanent magnet 15 is on the symmetry line of the first "V"-shaped permanent magnet. The outer end of the semicircular permanent magnet 15 is 1.5 mm away from the outer circumference of the rotor.

[0019] A tangential permanent magnet 8 is provided between each two adjacent first V-shaped permanent magnets. The polarity of the opposing surfaces of the two adjacent tangential permanent magnets 8 is the same as the polarity of the first V-shaped permanent magnet between the two adjacent tangential permanent magnets 8 facing the outer circle of the rotor core 3. The distance from the midpoint of the inner end of the tangential permanent magnet 8 to the center of the rotor is 1 / 2 of the rotor radius. A second arc-shaped magnetic isolation air gap 17 is provided on the outer side of the tangential permanent magnet 8. There is a 1.5mm non-connected portion between the second arc-shaped magnetic isolation air gap 17 and the outer circle of the rotor. A "convex"-shaped magnetic isolation air gap 9 composed of a rectangular magnetic isolation air gap and a fan-shaped magnetic isolation air gap is provided on the inner side of the tangential permanent magnet steel 8. The outer side of the rectangular magnetic isolation air gap is connected to the short side of the inner end of the tangential permanent magnet steel 8 and the width of the outer side of the rectangular magnetic isolation air gap is smaller than the width of the short side of the inner end of the tangential permanent magnet steel 8. The centers of the two arc sides of the fan-shaped magnetic isolation air gap are both located at the center of the rotor. The corners of the fan-shaped magnetic isolation air gap are all rounded. There is a 1.5mm unconnected part between adjacent "convex"-shaped magnetic isolation air gaps 9.

Claims

1. A combined magnetic pole permanent magnet generator with an asymmetric magnetic pole center structure, comprising a shaft (1), a rear end cover (2), a rotor core (3), a stator core (5), a first rectangular permanent magnet steel (6), a second rectangular permanent magnet steel (7), a tangential permanent magnet steel (8), a front end cover (10), and a semicircular permanent magnet steel (15), characterized in that: The rotor is an asymmetric combined permanent magnet rotor; An even number of first V-shaped permanent magnets consisting of two first rectangular permanent magnets (6) are arranged along the circumferential direction near the outer circle of the rotor core (3), the outer polarities of the first V-shaped permanent magnets are arranged with N and S poles at intervals, the distance from the midpoint of the line connecting the inner ends of the two first rectangular permanent magnets (6) constituting the first V-shaped permanent magnet to the center of the rotor core (3) is 2 / 3 of the radius of the outer circle of the rotor core (3), the angle between the two first rectangular permanent magnets (6) constituting the first V-shaped permanent magnet is 80°, there is a 1.5 mm non-connected portion between the inner ends of the two first rectangular permanent magnets (6) constituting the first V-shaped permanent magnet, the inner and outer ends of the first rectangular permanent magnet (6) are both provided with a first arc-shaped magnetic isolation air gap (16), and there is a 1.5 mm non-connected portion between the first arc-shaped magnetic isolation air gap (16) and the outer circle of the rotor core (3); The outer side of the first "V"-shaped permanent magnet steel with the polarity of the N pole facing the outer circle of the rotor core (3) is designed with a second "V"-shaped permanent magnet steel composed of two second rectangular permanent magnet steels (7), the angle between the two second rectangular permanent magnet steels (7) forming the second "V"-shaped permanent magnet steel is 90 degrees, and there is a 1.5mm non-connected portion between the inner ends of the two second rectangular permanent magnet steels (7) forming the second "V"-shaped permanent magnet steel, and both inner and outer ends of the second rectangular permanent magnet steel (7) are provided with a right-angled trapezoidal magnetic isolation air gap (18), the height of the right-angled trapezoidal magnetic isolation air gap (18) is connected to the short side of the second rectangular permanent magnet steel (7) and the height of the right-angled trapezoidal magnetic isolation air gap (18) is less than the length of the short side of the second rectangular permanent magnet steel (7), both corners on the oblique waist side of the right-angled trapezoidal magnetic isolation air gap (18) are rounded, and the outer end of the right-angled trapezoidal magnetic isolation air gap (18) is 1.5mm away from the outer circle of the rotor core (3); A semicircular permanent magnet (15) is designed on the outer side of the first "V"-shaped permanent magnet with an S-pole polarity facing the outer circle of the rotor core (3), the center of the semicircular permanent magnet (15) is on the symmetry line of the first "V"-shaped permanent magnet, and the outer end of the semicircular permanent magnet (15) has a non-connected portion of 1.5 mm from the outer circle of the rotor; A tangential permanent magnet (8) is provided between each two adjacent first "V"-shaped permanent magnets. The polarity of the opposite surfaces of the two adjacent tangential permanent magnets (8) is the same as the polarity of the first "V"-shaped permanent magnet between the two adjacent tangential permanent magnets (8) toward the outer circle of the rotor core (3). The distance between the inner end midpoint of the tangential permanent magnet (8) and the center of the rotor is 1 / 2 of the rotor radius. A second arc-shaped magnetic isolation air gap (17) is provided on the outer side of the tangential permanent magnet (8). The second arc-shaped magnetic isolation air gap (17) is 1.5 mm away from the outer circle of the rotor. The connecting part is provided with a "convex" shaped magnetic isolation air gap (9) composed of a rectangular magnetic isolation air gap and a fan-shaped magnetic isolation air gap on the inner side of the tangential permanent magnet steel (8), the outer side of the rectangular magnetic isolation air gap is connected to the short side of the inner end of the tangential permanent magnet steel (8) and the width of the outer side of the rectangular magnetic isolation air gap is smaller than the width of the short side of the inner end of the tangential permanent magnet steel (8), the centers of the two arc sides of the fan-shaped magnetic isolation air gap are both located at the center of the rotor, the corners of the fan-shaped magnetic isolation air gap are all rounded, and there is a 1.5mm non-connected part between adjacent "convex" shaped magnetic isolation air gaps (9).

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