Composite excitation rotor structure and vehicle-mounted generator

Abstract

The application discloses a composite excitation rotor structure, which comprises a rotating shaft connected to the front and rear end covers of a generator through bearings, a first claw pole connected to the rotating shaft, and a second claw pole; the first claw pole has 2N claw tips; the second claw pole has the same size and number of claw tips as the first claw pole; the claw tip parts of the first claw pole and the second claw pole are alternately arranged along the circumferential periphery; permanent magnets are arranged in the gaps formed between adjacent claw tips; one end of each permanent magnet is connected to the claw tip of the first claw pole, and the other end of the permanent magnet is connected to the claw tip of the second claw pole through a non-magnetic partition block which offsets the permanent magnet from the middle position of the gap between adjacent claw tips. In the application, the magnetic flux that can pass through one side of the permanent magnet is greatly different from the magnetic flux that can pass through the other side of the permanent magnet; the harmonic components generated during the operation of the rotor can be offset from the harmonic components generated by the stator core, the harmonic components of the output power of the generator are reduced, and the quality of the output power is improved.

Description

Technical Field

[0001] This invention belongs to the field of generator technology, specifically relating to a rotor claw pole structure. Background Technology

[0002] Typically, the rotors of vehicle-mounted generators mostly use claw-pole rotor cores. A claw-pole rotor consists of several pairs of claw poles, with the two claw poles in each pair staggered. These claw poles are arranged circumferentially. A magnetic yoke with an excitation winding is placed in the cavity inside the claw pole. The magnetic yoke is fixed to the end cover. The excitation winding is wound with high-insulation and high-strength enameled wire. When current is applied to the excitation winding, an axial magnetic flux is generated in the magnetic yoke, causing the claw tips on a pair of claw poles to be magnetized into N and S poles, respectively. The claw tips of several pairs of claw poles form staggered N and S poles. These magnetized claw tips provide magnetic flux to the stator core. After entering the gap between the stator and rotor, the flux passes sequentially through the stator core teeth, the stator core yoke, and then back into the gap between the core teeth and the stator and rotor, where it is received again by the claw tips on the rotor. Increasing the magnetic flux can improve the output power of a product. Currently, this problem is usually solved by adding permanent magnets circumferentially between the claw tips. However, the inventors have found that rotors manufactured in this way will generate higher third harmonic components during operation, resulting in poor power quality of the generator output. It is necessary to specially design the shape of the claw poles, claw tips and the permanent magnets placed between the claw tips. However, irregular structures will increase the processing difficulty of the claw poles, claw tips and permanent magnets. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and provide a composite excitation rotor structure for vehicle-mounted generators. Without increasing the overall size of the generator, the composite excitation rotor is formed by biasing and installing permanent magnets in the empty space between the claw poles to increase the generator rotor magnetic flux, thereby improving the power density of the product.

[0004] The technical solution of the present invention is as follows: a composite excitation rotor structure, comprising a shaft connected to the front and rear end covers of a generator via bearings, a first claw pole, a second claw pole connected to the shaft, a magnetic yoke fixed to the rear end cover of the generator, and an excitation coil wound on the magnetic yoke; the first claw pole has 2n claw tips; the second claw pole has claw tips of the same size and number as the first claw pole; the claw tips of the first and second claw poles are alternately placed along the outer periphery of a circle; 4n gaps are formed between adjacent claw tips; permanent magnets are spaced apart in the 4n gaps; all permanent magnets have the same polarity orientation; and a non-magnetic spacer is included to deviate the permanent magnets from the middle position of the gaps between adjacent claw tips; one end of each permanent magnet is connected to the claw tip of the first claw pole, and the other end is connected to the claw tip of the second claw pole via the non-magnetic spacer.

[0005] The permanent magnet is rectangular in shape, with N poles and S poles at both ends.

[0006] All permanent magnets have the same polarity orientation, specifically: the S-end of each permanent magnet is connected to the tip of the first claw pole, and the N-end is connected to the tip of the second claw pole via a non-magnetic spacer.

[0007] All permanent magnets have the same polarity orientation, specifically: the N-end of each permanent magnet is connected to the tip of the first claw pole, and the S-end is connected to the tip of the second claw pole via a non-magnetic spacer.

[0008] The ratio of the length A of the non-magnetic spacer to the length B of the permanent magnet is 1:7~9.

[0009] The non-magnetic spacer is made of austenitic stainless steel, copper, or aluminum alloy.

[0010] One end of the permanent magnet is attached to the tip of the first claw pole, and the other end is attached to the non-magnetic spacer. The other end of the non-magnetic spacer is attached to the tip of the second claw pole.

[0011] One end of the permanent magnet is bonded to the tip of the first claw pole with high-strength structural adhesive, and the other end is bonded to the non-magnetic spacer 12 with high-strength structural adhesive; the other end of the non-magnetic spacer 12 is bonded to the tip of the second claw pole with high-strength structural adhesive.

[0012] The first claw is a ring claw, and the second claw is a disc claw.

[0013] The first claw is a circular claw, and the second claw is a ring claw.

[0014] The present invention also provides a vehicle-mounted generator, including a housing, a stator assembly disposed within the housing, and a rotor assembly; the rotor assembly adopts the above-mentioned composite excitation rotor structure.

[0015] Because the magnetic flux flowing from the rotor core to the stator core contains harmonic components, magnetic field distortion occurs. These harmonic components, generated by the magnetic force acting on the stator core teeth, produce harmonic components in the radial and circumferential directions of the rotor core, causing high-frequency oscillations in the stator core teeth and resulting in noise. To solve this problem, in this invention, the permanent magnet is installed on one side near each claw tip, rather than in the middle of the gap between adjacent claw tips. The permanent magnet is oriented and fixed circumferentially in the rotor core structure, resulting in a significant difference in the magnetic flux that can pass through one side of the permanent magnet compared to the other. The harmonic components generated by the claw-pole rotor structure provided by this invention cancel out the harmonic components generated by the stator core, thereby reducing harmonics in the generator output power supply and improving the quality of the output power supply. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the vehicle-mounted generator of the present invention.

[0017] Figure 2 This is a schematic diagram of the composite excitation rotor of the present invention.

[0018] Figure 3 This is a perspective view of the composite excitation rotor of the present invention.

[0019] Figure 4 This is an exploded view of the composite excitation rotor of the present invention.

[0020] Figure 5 This is a schematic diagram of the radial cross-section of the composite excitation rotor of the present invention. Detailed Implementation

[0021] Figure 1 The diagram shows the structure of the vehicle-mounted generator of the present invention. The front cover 7, housing 8, and rear cover 10 are structural support components of the product, supporting the non-moving parts of the motor. The rotating parts are supported by bearings 6 arranged in two different positions and achieve rotational movement. The stator assembly 1 is assembled inside the housing 8. The composite excitation rotor consists of a first claw pole 2, a second claw pole 3, and a rotating shaft 13. An axial magnetic field is provided by a magnetic yoke 5 mounted on the rear cover and an energized excitation coil 4, which magnetizes the first claw pole 2 and the second claw pole 3 into N and S poles, respectively, providing magnetic flux into the stator assembly 1 to complete power generation.

[0022] like Figures 2-5As shown, the first claw pole 2 (ring claw) has 2n claw tips; inside the rotor core structure is a yoke made of soft magnetic material, on which coils are wound, generating magnetic flux that flows along the axial direction of the core when current is applied. The second claw pole 3 (disc claw) has claw tips of the same size and number as the first claw pole 2. The claw tips of the first claw pole 2 and the second claw pole 3 are alternately placed along the circumference of the claw pole rotor, with the same number of gaps between adjacent claw tips. Regularly shaped permanent magnets 11 of the same polarity and non-magnetic spacers 12 are spaced within these gaps, forming a composite excitation claw pole rotor with the first and second claw poles. One end of each permanent magnet 11 is connected to the claw tip of the first claw pole 2, and the other end is connected to the claw tip of the second claw pole 3 via the non-magnetic spacer 12. The permanent magnet 11 is cuboid in shape, with N and S poles at its two ends, respectively. Half of the permanent magnets have their N-pole ends connected to the claw tips of the first claw pole, and the adjacent permanent magnets have their S-pole ends connected to the claw tips of the first claw pole. One end of the permanent magnet 11 is bonded to the tip of the first claw pole 2 with high-strength structural adhesive, and the other end is bonded to the non-magnetic spacer 12 with high-strength structural adhesive. The other end of the non-magnetic spacer 12 is bonded to the tip of the second claw pole 3 with high-strength structural adhesive. The non-magnetic spacer 12 ensures that the permanent magnet 11 between each claw pole is not located at the center of the claw tip interval, but is offset to one side. The ratio of the length A of the non-magnetic spacer 12 to the length B of the permanent magnet 11 is set between 1:7 and 1:9. This ratio can minimize harmonic components while ensuring that the permanent magnet of sufficient size provides magnetic flux, allowing the motor to output greater power. The offset arrangement of the permanent magnet 11 results in a significant difference in magnetic flux on one side of the claw tip compared to the other side, creating a rotor skew effect, thereby reducing the harmonic content in the magnetic flux provided by the rotor core.

[0023] The magnetic flux lines provided by a pair of claw tips and a permanent magnet in the composite excitation claw pole rotor of this invention during operation are as follows: Figure 5 As shown, the magnetic flux on one side of the claw tip is significantly different from that on the other side, which causes the structure to form a rotor skew effect, thereby reducing the harmonic content in the magnetic flux provided by the rotor core.

Claims

1. A composite excitation rotor structure, comprising a shaft connected to the front and rear end covers of a generator via bearings, a first claw pole, a second claw pole connected to the shaft, a magnetic yoke fixed to the rear end cover of the generator, and an excitation coil wound on the magnetic yoke; the first claw pole has 2n claw tips; the second claw pole has claw tips of the same size and number as the first claw pole; the claw tips of the first and second claw poles are alternately placed along the circumference; characterized in that: There are 4n gaps between adjacent claw tips; permanent magnets are arranged in the 4n gaps; all permanent magnets have the same polarity orientation; and there is also a non-magnetic spacer for offsetting the permanent magnets from the middle position of the gaps between adjacent claw tips; one end of each permanent magnet is connected to the claw tip of the first claw pole, and the other end is connected to the claw tip of the second claw pole via the non-magnetic spacer.

2. The composite excitation rotor structure according to claim 1, characterized in that: The permanent magnet is rectangular in shape, with N poles and S poles at both ends.

3. The composite excitation rotor structure according to claim 2, characterized in that: All permanent magnets have the same polarity orientation, specifically: the S-end of each permanent magnet is connected to the tip of the first claw pole, and the N-end is connected to the tip of the second claw pole via a non-magnetic spacer.

4. The composite excitation rotor structure according to claim 2, characterized in that: All permanent magnets have the same polarity orientation, specifically: the N-end of each permanent magnet is connected to the tip of the first claw pole, and the S-end is connected to the tip of the second claw pole via a non-magnetic spacer.

5. The composite excitation rotor structure according to claim 1, characterized in that: The ratio of the length A of the non-magnetic spacer to the length B of the permanent magnet is 1:7~9.

6. The composite excitation rotor structure according to claim 1, characterized in that: The non-magnetic spacer is made of austenitic stainless steel, copper, or aluminum alloy.

7. The composite excitation rotor structure according to claim 1, characterized in that: One end of the permanent magnet is attached to the tip of the first claw pole, and the other end is attached to the non-magnetic spacer. The other end of the non-magnetic spacer is attached to the tip of the second claw pole.

8. The composite excitation rotor structure according to claim 1, characterized in that: The first claw is a ring claw, and the second claw is a disc claw.

9. The composite excitation rotor structure according to claim 1, characterized in that: The first claw is a circular claw, and the second claw is a ring claw.

10. A vehicle-mounted generator, comprising a housing, a stator assembly and a rotor assembly disposed within the housing; characterized in that: The rotor assembly adopts the composite excitation rotor structure as described in any one of claims 1-9.

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