Brushless reverse claw-pole electric excitation generator for automobiles

Abstract

The present invention provides a brushless reverse claw-pole electromagnetic generator for automobiles, belonging to the technical field of automotive motors and electrical appliances. The generator comprises a front cover, a rear cover, front claw poles, rear claw poles, an excitation winding, a magnetic yoke, a plastic frame, an armature winding, a stator, and a rotating shaft. The front claw poles extend in a trumpet-like manner to form a larger annular magnetic conductor, while the rear claw poles contract in a bottleneck-like manner to form a smaller annular magnetic conductor. This results in a reverse claw-pole electromagnetic rotor with spaced N and S poles, an equal number of poles, and uniform distribution along a circular path. This structure increases the radial spacing of the excitation winding and shortens the axial length, resulting in a uniform magnetic field distribution, high power density, and low harmonic content of the induced electromotive force. This achieves a highly sinusoidal voltage waveform under power generation conditions. The entire generator adopts a brushless structure, eliminating the easily worn carbon brush slip ring structure and providing high reliability.

Description

Technical Field

[0001] The invention provides a brushless reverse claw-pole electric excitation generator for automobiles, belonging to the technical field of automobile motors and electrical appliances. Background Art

[0002] Electromagnetic claw-pole generators are widely used in automobiles due to their simple manufacturing, low cost, and good operating stability. However, with the advancement of automobile technology, the number of electrical devices in automobiles has increased. The problems of low output efficiency, low power density, and high output voltage harmonic content of traditional claw-pole generators have become increasingly prominent, and they are gradually unable to meet the needs of use. In addition, the presence of carbon brushes and mechanical commutators not only limits the overload capacity of the generator, but also requires frequent maintenance and replacement of carbon brushes and commutators if they are operated for a long time. Therefore, the performance of electromagnetic claw-pole generators needs to be further improved. Summary of the Invention

[0003] The object of the present invention is to provide a brushless reverse claw-pole electric excitation generator for automobiles that can overcome the above-mentioned drawbacks, has a large radial arrangement space for the electric excitation winding, uniform magnetic field distribution, high power density, low induced electromotive force harmonic content, no carbon brushes and mechanical commutator, and a low failure rate. The technical contents are as follows:

[0004] The brushless reverse claw pole electric excitation generator for automobiles is composed of a front cover, a rear cover, a front claw pole, a rear claw pole, an electric excitation winding, a magnetic ring, a plastic frame, an armature winding, a stator, and a rotating shaft. The characteristics are: the electric excitation generator rotor is a reverse claw pole structure;

[0005] The electromagnetic rotor of the reverse claw pole is composed of a front claw pole, a rear claw pole, an electromagnetic excitation winding, a magnetic ring, and a plastic frame. The claws of the front claw pole and the rear claw pole adopt the same isosceles trapezoidal variable cross-section structure. The thickness and width at the claw tip are smaller than the claw root. The claw tips of the front claw pole and the rear claw pole point in the same direction. The length from the claw tip to the claw root is the same as the axial length of the stator. The front claw pole expands outward in a trumpet shape at the front claw pole yoke to form the claw pole support part of the front claw pole. The outer diameter of the front claw pole yoke is larger than the maximum outer diameter of the claw root. The claw pole support part of the front claw pole The outer diameter is larger than the inner diameter of the stator and smaller than the outer diameter of the stator. The rear claw pole shrinks inward at the rear claw pole yoke to form the claw pole support part of the rear claw pole. The magnetic ring, the electric excitation winding and the plastic frame are placed between the two claw pole support parts. The electric excitation winding is wound on the plastic frame, and the plastic frame is sleeved on the magnetic ring. The magnetic ring is fixed to the rear end cover by screws. The rear claw pole is welded to the front claw pole by non-magnetic material. The front claw pole is pressed on the rotating shaft to form an alternate arrangement of N poles and S poles. The number of poles is equal and evenly distributed along the circle.

[0006] Working Principle: When excitation current flows through the field winding, the claw poles become magnetized, and the shaft drives the claw poles to rotate. The rotor generates a spatially rotating magnetic field, causing the magnetic flux in the stator winding to alternate. Based on the principle of electromagnetic induction, an alternating induced electromotive force is generated in the three-phase stator winding. The three-phase AC current is then rectified by a rectifier to output DC power. Because the yoke of the electrically excited brushless claw pole generator is fixed to the rear end cover by screws and does not rotate with the rotor, a carbon brush slip ring structure is not required.

[0007] Compared with the prior art, the claws of the front and rear claw poles of the present invention both adopt an isosceles trapezoidal variable cross-section structure. The thickness of the claw tip is smaller than the thickness of the claw root, which can reduce the amount of claw material used and reduce the weight of the entire machine. The width of the claw tip is smaller than the width of the claw root, which can significantly increase the distance between adjacent claws, reduce leakage magnetic flux, and eliminate the need to add additional magnetic isolation material between adjacent claws. This achieves high air gap magnetic density while effectively improving the efficiency of the entire machine and reducing the manufacturing cost of the motor.

[0008] The front claw pole expands outward in a trumpet shape at the front claw pole yoke to form the claw pole support part of the front claw pole. There is no need to increase the radial size of the motor at the expense of reducing the size of the claw part, avoiding the phenomenon that the magnetic field at the claw root reaches saturation earlier than the claw tip. The magnetic field distribution is more uniform, which effectively reduces the content of harmonics in the induced electromotive force, increases the layout space of the electric excitation winding, and improves the power density of the whole machine. At the same time, the whole machine adopts a brushless structure, eliminating the easily worn carbon brush slip ring structure, and has high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural diagram of an embodiment of the present invention;

[0010] Figure 2 1 is a cross-sectional view of the embodiment shown in FIG.

[0011] In the figure: 1, rear end cover 2, rotating shaft 3, magnetic ring 4, rear claw pole 5, plastic frame 6, electric excitation winding 7, front claw pole 8, stator 9, armature winding 10, front end cover 11, fan 12, bearing 13, pulley 14, screws. DETAILED DESCRIPTION

[0012] The present invention will be further described below in conjunction with the accompanying drawings:

[0013] A brushless reverse claw pole electric excitation generator for automobiles is composed of a front end cover 10, a rear end cover 1, a front claw pole 7, a rear claw pole 4, an electric excitation winding 6, a magnetic ring 3, a plastic frame 5, an armature winding 9, a stator 8, and a rotating shaft 2. The characteristic of the electric excitation generator rotor is that it has a reverse claw pole structure.

[0014] The electromagnetic rotor of the reverse claw pole is composed of a front claw pole 7, a rear claw pole 4, an electromagnetic excitation winding 6, a magnetic ring 3, and a plastic frame 5. The claws of the front claw pole 7 and the rear claw pole 4 adopt the same isosceles trapezoidal variable cross-section structure. The thickness and width at the claw tip are smaller than the claw root. The claw tips of the front claw pole 7 and the rear claw pole 4 point in the same direction. The length from the claw tip to the claw root is the same as the axial length of the stator. The front claw pole 7 expands outward in a trumpet shape at the front claw pole yoke to form a claw pole support part of the front claw pole 7. The outer diameter of the front claw pole yoke is larger than the maximum outer diameter at the claw root. The outer diameter of the claw pole support part of the front claw pole 7 is larger than the maximum outer diameter at the claw root. The diameter is larger than the inner diameter of the stator and smaller than the outer diameter of the stator. The rear claw pole 4 shrinks inward at the rear claw pole yoke to form a claw pole support part of the rear claw pole 4. The magnetic ring 3, the electric excitation winding 6 and the plastic frame 5 are placed between the two claw pole support parts. The electric excitation winding 6 is wound on the plastic frame 5. The plastic frame 5 is sleeved on the magnetic ring 3. The magnetic ring 3 is fixed to the rear end cover 1 by screws 14. The rear claw pole 7 is welded to the front claw pole 7 by non-magnetic material. The front claw pole 7 is pressed onto the rotating shaft 2, forming an N pole and an S pole arranged at intervals. The number of poles is equal and evenly distributed along the circle.

Claims

1. A brushless reverse claw pole electromagnetic generator for automobiles, comprising a front end cover (10), a rear end cover (1), a front claw pole (7), a rear claw pole (4), an electromagnetic excitation winding (6), a magnetic ring (3), a plastic frame (5), an armature winding (9), a stator (8), and a rotating shaft (2), characterized in that: The rotor of the electromagnetic generator is a reverse claw pole structure; The electromagnetic rotor of the reverse claw pole is composed of a front claw pole (7), a rear claw pole (4), an electromagnetic excitation winding (6), a magnetic ring (3), and a plastic frame (5). The claws of the front claw pole (7) and the rear claw pole (4) adopt the same isosceles trapezoidal variable cross-section structure. The thickness and width at the claw tip are both smaller than those at the claw root. The claw tips of the front claw pole (7) and the rear claw pole (4) point in the same direction. The length from the claw tip to the claw root is the same as the axial length of the stator. The front claw pole (7) expands outward in a trumpet shape at the front claw pole yoke to form a claw pole support portion of the front claw pole (7). The outer diameter of the front claw pole yoke is larger than the maximum outer diameter at the claw root. The outer diameter of the claw pole support portion of the front claw pole (7) is larger than the stator. The inner diameter of the stator is smaller than the outer diameter of the stator, the rear claw pole (4) shrinks inward at the rear claw pole yoke to form a claw pole support portion of the rear claw pole (4), and a magnetic ring (3), an electric excitation winding (6) and a plastic frame (5) are placed between the two claw pole support portions. The electric excitation winding (6) is wound on the plastic frame (5), and the plastic frame (5) is sleeved on the magnetic ring (3). The magnetic ring (3) is fixed to the rear end cover (1) by screws (14), and the rear claw pole (7) is welded to the front claw pole (7) by non-magnetic material. The front claw pole (7) is pressed onto the rotating shaft (2), forming an N pole and an S pole arranged at intervals, with an equal number of poles and uniform distribution along the circle.

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