Stator structure of three-phase outer rotor motor

Abstract

A stator structure of a three-phase outer rotor motor includes a stator core of the three-phase outer rotor motor, wherein the total number of stator tooth poles uniformly distributed on the outer circumference of the stator core is an odd multiple of 3, and the three-phase windings of the stator are divided into two groups, one group of three-phase windings is wound from a starting pole to an output pole in a clockwise direction, and the other group of three-phase windings is wound from a starting pole to an output pole in a counterclockwise direction. The two groups of three-phase windings have the same number of stator tooth poles, and the winding turns on each stator tooth pole are equal. The number of winding turns on the three output poles of the stator tooth pole is equal, and the number of winding turns of the two groups is 1 / 2 for each group. The v-phase windings of the two groups are both wound on one output pole and connected in parallel as the v-phase lead-out wires, the u-phase windings of one group and the w-phase windings of the other group are wound on another output pole, the w-phase windings of one group and the u-phase windings of the other group are wound on the third output pole, the u-phase windings of the two groups are connected in parallel as the u-phase lead-out wires, and the w-phase windings of the two groups are connected in parallel as the w-phase lead-out wires.

Description

Technical Field

[0001] The present invention relates to the field of three-phase outer rotor motors of power machinery, and in particular to a stator structure of a three-phase outer rotor motor. Background Art

[0002] A three-phase outer rotor motor is mounted on a main shaft, with the motor rotor fixed to the motor housing and the stator fixed to the main shaft. The stator of a three-phase outer rotor motor consists of a stator core and windings. Multiple stator teeth are evenly distributed around the outer circumference of the stator core, with winding slots formed between adjacent stator teeth. The stator winding is wound around the stator teeth, generating a rotating magnetic field when energized.

[0003] Currently, external rotor motors in power machinery are commonly used in high-power output power machinery such as lawn mowers and electric vehicles. Their stator windings are composed of three-phase windings, with each phase winding consisting of a single enameled wire wound across the stator teeth. Because the stator windings of the motor need to pass high currents, for each set of stator windings, the enameled wire of each phase is wound once around the stator's outer circumference in the same direction. To prevent the motor from burning out due to excessive heat generated by the enameled wire, each phase needs to be wound with a single large-diameter enameled wire. However, large-diameter enameled wire is not easy to wind around the stator teeth, and sometimes even impossible to wind.

[0004] Currently, two sets of stator windings are wound in parallel to increase the cross-sectional area of current flow and reduce heat generation. In this type of stator with two sets of stator windings, the following are two stator windings: one set of enameled wires of both sets of stator windings are wound around the outer circumference of the stator in the same direction, and each stator tooth pole requires two enameled wire turns of the same phase. This makes the cross-wires between the stator teeth complex, the appearance is messy, the winding difficulty is increased, and the processing time is extended. The other set of enameled wires of the two sets of stator windings are arranged on the stator in an axially symmetrical manner, with one set of windings wound clockwise and the other set wound counterclockwise. In this winding structure, only one enameled wire is wound around each stator tooth pole. However, if the total number of stator teeth in this structure is an odd multiple of 3, the stator must leave three stator teeth vacant and unwound. As a result, the magnetic field generated by the stator windings is not completely evenly distributed around the outer circumference of the stator, resulting in a decrease in the electrical performance of the motor. Summary of the Invention

[0005] The present invention addresses the shortcomings of the prior art by providing a stator structure for a three-phase outer rotor motor. By connecting two sets of three-phase windings in parallel, the stator structure increases the cross-sectional area of current flow and reduces heat generation. Furthermore, the two sets of three-phase windings are arranged symmetrically, resulting in fewer crossovers between stator teeth and a more aesthetically pleasing design. Furthermore, the structure ensures that each stator tooth is wound with the same number of turns, with no vacant turns. When the windings are energized, a uniform magnetic field is formed, thereby improving the motor's electrical performance.

[0006] The technical solution of the present invention is: a stator structure of a three-phase outer rotor motor, including a stator core of the three-phase outer rotor motor, wherein the total number of stator tooth poles uniformly distributed on the outer circumference of the stator core is an odd multiple of 3, the three-phase windings of the stator are divided into two groups, and the six stator tooth poles adjacent to each other on the stator core are axially symmetrically divided into two groups of starting poles of the three-phase windings, the u-phase starting poles of the two groups of three-phase windings are adjacent, the u-phase, v-phase, and w-phase windings of one group are respectively wound from the starting poles of the stator tooth poles to the output poles in the clockwise direction of the circumference of the stator core, and the u-phase, v-phase, and w-phase windings of the other group are respectively wound from the starting poles of the stator tooth poles to the output poles in the counterclockwise direction of the circumference of the stator core. The two groups of three-phase windings are wound on the same number of stator tooth poles, and the number of winding turns on each stator tooth pole is equal and even. The number of winding turns on the three output poles of the stator tooth pole is 1 / 2 of the windings of the two groups. Among them, the v-phase windings of the two groups are wound on one output pole and connected in parallel as the v-phase lead-out line, the u-phase winding of one group and the w-phase winding of the other group are wound on another output pole, and the w-phase winding of one group and the u-phase winding of the other group are wound on the third output pole, and the u-phase windings of the two groups are connected in parallel as the u-phase lead-out line, and the w-phase windings of the two groups are connected in parallel as the w-phase lead-out line, and the w-phase, v-phase and u-phase winding ends of each group of starting poles are connected in star point.

[0007] The stator core is provided with 21 stator tooth poles, wherein the 7th, 8th and 9th stator tooth poles are the starting poles of a group of three-phase windings, the 10th, 11th and 12th stator tooth poles are the starting poles of another group of three-phase windings, and the 19th, 20th and 21st stator tooth poles are the outgoing poles of the two groups of three-phase windings.

[0008] The number of turns wound on each stator tooth pole is 14 turns. Among them, one group of u-phase windings on the 19th stator tooth pole is wound with 7 turns, and the other group of w-phase windings is wound with 7 turns. The 20th stator tooth pole has one group of v-phase windings on the 20th stator tooth pole and another group of v-phase windings is wound with 7 turns. The 21st stator tooth pole has one group of w-phase windings on the 21st stator tooth pole and another group of u-phase windings is wound with 7 turns.

[0009] In the two groups of three-phase windings, the u phase of one group starts from the 9th stator tooth pole and goes through the 6th and 3rd stator tooth poles to the 21st stator tooth pole in a clockwise direction. The v phase starts from the 8th stator tooth pole and goes through the 5th and 2nd stator tooth poles to the 20th stator tooth pole in a clockwise direction. The w phase starts from the 7th stator tooth pole and goes through the 4th and 1st stator tooth poles to the 19th stator tooth pole in a clockwise direction. The u-phase of a group starts from the 10th stator tooth pole and is wound in a counterclockwise direction through the 13th and 16th stator tooth poles to the 19th stator tooth pole. The v-phase starts from the 11th stator tooth pole and is wound in a counterclockwise direction through the 14th and 17th stator tooth poles to the 20th stator tooth pole. The w-phase starts from the 12th stator tooth pole and is wound in a clockwise direction through the 15th and 18th stator tooth poles to the 21st stator tooth pole.

[0010] The stator core is provided with u-phase, v-phase and w-phase terminals, which are respectively adjacent to the three output poles, the v-phase lead wire is welded and fixed to the v-phase terminal, the u-phase lead wire is welded and fixed to the u-phase terminal, and the w-phase lead wire is welded and fixed to the w-phase terminal.

[0011] The above technical solution is adopted: comprising a stator core of a three-phase outer rotor motor, wherein the total number of stator tooth poles uniformly distributed on the outer circumference of the stator core is an odd multiple of 3, and the three-phase windings of the stator are divided into two groups, and the six stator tooth poles adjacent to each other on the stator core are axially symmetrically divided into two groups of starting poles of the three-phase windings, and the u-phase starting poles of the two groups of three-phase windings are adjacent, and the u-phase, v-phase, and w-phase windings of one group are respectively wound from the starting poles of the stator tooth poles to the output poles in the clockwise direction of the circumference of the stator core, and the u-phase, v-phase, and w-phase windings of the other group are respectively wound from the starting poles of the stator tooth poles to the output poles in the counterclockwise direction of the circumference of the stator core. The two groups The three-phase windings are wound around the same number of stator teeth, with an even number of turns on each stator tooth. The three output poles of the stator teeth each have two groups of windings, each accounting for 1 / 2 of the total number of turns. The two groups of V-phase windings are each wound around one output pole and connected in parallel as the V-phase lead wires. The U-phase windings of one group and the W-phase windings of the other group are wound on another output pole. The W-phase windings of one group and the W-phase windings of the other group are wound on the third output pole. The two groups of U-phase windings are connected in parallel as the U-phase lead wires. The W-phase windings of the two groups are connected in parallel as the W-phase lead wires. The W-phase, V-phase, and U-phase winding ends of each starting pole are connected in star points. This stator winding consists of two parallel groups of three-phase windings connected in star formation. This ensures that the stator windings of a high-power external rotor motor have a sufficiently large cross-sectional area for current flow when high currents are applied, thereby reducing heat generation and preventing motor damage due to overheating. Furthermore, one set of three-phase windings winds clockwise around the output pole, while the other set winds counterclockwise around the output pole, forming two symmetrical sets of three-phase windings. Each set of W, V, and U phase windings only winds around half of the stator's outer circumference, reducing the number of wires crossing between stator teeth. This improves the appearance, reduces the winding difficulty, and improves processing efficiency. Furthermore, even if the total number of stator teeth in the outer rotor motor's stator is an odd multiple of 3, it ensures that each stator tooth is wound with windings, and the number of turns is the same. This prevents unused stator teeth on the stator, ensuring that the magnetic field formed by the stator windings is completely evenly distributed around the stator's outer circumference when energized, thereby improving the motor's electrical performance.

[0012] The stator core is provided with 21 stator teeth. The 7th, 8th, and 9th stator teeth serve as the starting poles for one set of three-phase windings, the 10th, 11th, and 12th stator teeth serve as the starting poles for another set of three-phase windings, and the 19th, 20th, and 21st stator teeth serve as the exit poles for both sets of three-phase windings. 21 is an odd multiple of 3, allowing the two sets of three-phase windings to be symmetrically wound around the stator core with 21 stator teeth, ensuring uniform winding distribution. Each stator tooth has 14 turns. The 19th stator tooth has 7 turns of U-phase winding for one set and 7 turns of W-phase winding for the other set. The 20th stator tooth has 7 turns of V-phase winding for one set and 7 turns of V-phase winding for the other set. The 21st stator tooth has 7 turns of W-phase winding for one set and 7 turns of U-phase winding for the other set. This ensures that all three output poles are equally wound with 14 turns, making the stator windings evenly distributed. In the two groups of three-phase windings, the u-phase of one group starts from the 9th stator tooth pole and goes through the 6th and 3rd stator tooth poles in a clockwise direction to the 21st stator tooth pole, the v-phase starts from the 8th stator tooth pole and goes through the 5th and 2nd stator tooth poles in a clockwise direction to the 20th stator tooth pole, and the w-phase starts from the 7th stator tooth pole and goes through the 4th and 1st stator tooth poles in a clockwise direction to the 19th stator tooth pole. The U-phase of one set is wound counterclockwise from the 10th stator tooth through the 13th and 16th stator teeth, to the 19th stator tooth. The V-phase is wound counterclockwise from the 11th stator tooth through the 14th and 17th stator teeth, to the 20th stator tooth. The W-phase is wound clockwise from the 12th stator tooth through the 15th and 18th stator teeth, to the 21st stator tooth. Thus, the six windings in both sets are wound neatly and orderly around the stator teeth, making the winding process simple and quick.

[0013] The stator core is equipped with U-phase, V-phase, and W-phase terminal blocks, each adjacent to the three output poles. The V-phase lead wire is welded to the V-phase terminal block, the U-phase lead wire is welded to the U-phase terminal block, and the W-phase lead wire is welded to the W-phase terminal block. The U-phase, V-phase, and W-phase terminal blocks facilitate the lead-out of the stator windings, ensuring more standardized wiring.

[0014] The stator structure of this three-phase outer rotor motor utilizes two parallel sets of three-phase windings to increase the cross-sectional area of current flow and reduce heat generation. The two sets of three-phase windings are symmetrically arranged, resulting in a minimal crossover between stator teeth and a more aesthetically pleasing design. Furthermore, two different sets of windings are wound around each of the three output poles, each occupying half of the total length. This ensures that each stator tooth has the same number of turns, eliminating any unused windings. When the windings are energized, a uniform magnetic field is formed, improving the motor's electrical performance.

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the front view of the stator structure of the three-phase outer rotor motor;

[0017] Figure 2 Schematic diagram of the back side of the stator structure of the three-phase outer rotor motor;

[0018] Figure 3 Schematic diagram of a set of windings of the stator structure of the three-phase outer rotor motor;

[0019] Figure 4 FIG. 2 is a schematic diagram of another set of windings of the stator structure of the three-phase outer rotor motor. DETAILED DESCRIPTION

[0020] See also Figures 1 to 4A stator structure of a three-phase outer rotor motor includes a stator core 1 of the three-phase outer rotor motor. The stator core 1 is formed by stacking a plurality of stator punchings, and a mounting hole is provided at the center of the stator core 1. The total number of stator teeth 2 evenly distributed on the outer circumference of the stator core 1 is an odd multiple of 3, that is, 3*(2n+1) stator teeth, where n is a positive integer. Each stator tooth 2 extends in the radial direction of the stator, and a spacing is left between adjacent stator teeth 2. The three-phase windings of the stator are divided into two groups, and each phase winding is an enameled wire. The six stator teeth adjacent to each other on the stator core 1 are axially symmetrically divided into two groups of starting poles 3 of the three-phase windings, and the u-phase starting poles of the two groups of three-phase windings are adjacent. One set of U-, V-, and W-phase windings 10 are wound clockwise around the circumference of the stator core 1, starting from the starting pole of the stator tooth 2 and ending at the output pole 4. The other set of U-, V-, and W-phase windings 6 are wound counterclockwise around the circumference of the stator core 1, starting from the starting pole of the stator tooth 2 and ending at the output pole 4. Each phase of the two sets of three-phase windings is wound around n stator teeth. The number of turns on each stator tooth 2 is equal and even. The number of turns on the three output poles 4 of the stator tooth is 1 / 2 for each set of windings. The winding directions of the windings on each stator tooth 2 are consistent. The V-phase windings of both sets are wound around one output pole and connected in parallel as the V-phase lead wires. The U-phase windings of one set are wound around the other output pole with the W-phase windings of the other set, and the W-phase windings of one set are wound around the third output pole with the U-phase windings of the other set. The two groups of u-phase windings are connected in parallel as the u-phase lead-out wires, and the two groups of w-phase windings are connected in parallel as the w-phase lead-out wires. The w-phase, v-phase, and u-phase winding ends 11 of each starting pole group are fixed using a star point connection. In this embodiment, a total of 21 stator teeth 2 are evenly distributed around the outer circumference of the stator core 1. That is, when n = 3, the 7th, 8th, and 9th stator teeth are the starting poles of one group of three-phase windings, the 10th, 11th, and 12th stator teeth are the starting poles of another group of three-phase windings, and the 19th, 20th, and 21st stator teeth are the output poles of the two groups of three-phase windings. 21 is an odd multiple of 3, so the two groups of three-phase windings can be symmetrically wound around the stator core 1 with 21 stator teeth, ensuring uniform winding distribution. Each stator tooth pole 2 has 14 turns. The 19th stator tooth pole has 7 turns of U-phase winding in one group and 7 turns of W-phase winding in another group. The 20th stator tooth pole has 7 turns of V-phase winding in one group and 7 turns of V-phase winding in another group. The 21st stator tooth pole has 7 turns of W-phase winding in one group and 7 turns of U-phase winding in another group. This ensures that all three output poles have 14 turns, making the stator winding uniformly distributed.In the two groups of three-phase windings, the u phase of one group starts from the 9th stator tooth pole and goes through the 6th and 3rd stator tooth poles to the 21st stator tooth pole in a clockwise direction. The v phase starts from the 8th stator tooth pole and goes through the 5th and 2nd stator tooth poles to the 20th stator tooth pole in a clockwise direction. The w phase starts from the 7th stator tooth pole and goes through the 4th and 1st stator tooth poles to the 19th stator tooth pole in a clockwise direction. The U-phase of one set is wound counterclockwise from the 10th stator tooth through the 13th and 16th stator teeth, to the 19th stator tooth. The V-phase is wound counterclockwise from the 11th stator tooth through the 14th and 17th stator teeth, to the 20th stator tooth. The W-phase is wound clockwise from the 12th stator tooth through the 15th and 18th stator teeth, to the 21st stator tooth. Thus, the six windings in both sets are wound neatly and orderly around the stator teeth, making the winding process simple and quick. The u-phase winding on the 19th stator tooth pole and the u-phase winding on the 21st stator tooth pole are stripped and twisted together to form a parallel connection as the u-phase lead wire 5; the two v-phase windings on the 20th stator tooth pole are stripped and twisted together to form a parallel connection as the v-phase lead wire 7; the w-phase winding on the 19th stator tooth pole and the w-phase winding on the 21st stator tooth pole are stripped and twisted together to form a parallel connection as the w-phase lead wire 9. The stator core 1 is provided with u-phase, v-phase, and w-phase terminal blocks 8, which are adjacent to the three lead poles 4, respectively. The v-phase lead wire 7 is welded to the v-phase terminal block, the u-phase lead wire 5 is welded to the u-phase terminal block, and the w-phase lead wire 9 is welded to the w-phase terminal block. The u-phase, v-phase, and w-phase terminal blocks 8 facilitate the lead-out of the stator windings, making the wiring more standardized.

[0021] The present invention is not limited to stator cores with 21 stator teeth; the winding method described above can be used for stator cores with a total number of stator teeth of 15, 27, 33, or any other odd multiple of 3. The stator windings of this three-phase outer rotor motor are two sets of three-phase windings connected in parallel in a star configuration. This ensures that the stator windings of this high-power outer rotor motor have a sufficiently large cross-sectional area for current flow when high current is applied, thereby reducing heat generation and preventing motor damage due to overheating. Furthermore, one set of three-phase windings winds clockwise to the output pole 4, while the other set winds counterclockwise to the output pole 4, thereby forming two symmetrical sets of three-phase windings. Each set of W-phase, V-phase, and U-phase windings winds only around half of the stator's outer circumference, reducing the number of crossovers between the two stator teeth, improving the appearance, reducing winding difficulty, and improving processing efficiency. In addition, the total number of stator tooth poles of the outer rotor motor stator is an odd multiple of 3, and two different groups of windings are respectively wound on the three output poles, and the number of turns of each group is half. This ensures that each stator tooth pole 2 is wound with windings, and the number of turns of the windings is the same, thereby avoiding vacant stator tooth poles on the stator. The windings are symmetrical and uniform, so that the magnetic field formed by the stator winding being energized is completely evenly distributed on the outer circumference of the stator, thereby improving the electrical performance of the motor.

Claims

1. A stator structure of a three-phase outer rotor motor, comprising a stator core (1) of the three-phase outer rotor motor, characterized in that: The total number of stator tooth poles (2) uniformly distributed on the outer circumference of the stator core (1) is an odd multiple of 3, and is set to 21 stator tooth poles (2). The three-phase winding of the stator is divided into two groups, and the six stator tooth poles adjacent to each other on the stator core (1) are axially symmetrically divided into two groups of starting poles (3) of three-phase winding, wherein the 7th, 8th and 9th stator tooth poles are the starting poles of one group of three-phase winding, the 10th, 11th and 12th stator tooth poles are the starting poles of another group of three-phase winding, and the 19th, 20th and 21st stator tooth poles are the starting poles of two groups of three-phase winding. The winding output pole (4), the u-phase starting poles of the two groups of three-phase windings are adjacent, the u-phase, v-phase, and w-phase windings of one group are respectively wound from the starting pole of the stator tooth pole (2) to the output pole (4) in the clockwise direction of the circumference of the stator core (1), and the u-phase, v-phase, and w-phase windings of the other group are respectively wound from the starting pole of the stator tooth pole (2) to the output pole (4) in the counterclockwise direction of the circumference of the stator core (1). The number of stator tooth poles (2) wound by the two groups of three-phase windings is the same, and each stator tooth pole (2) has a The number of winding turns is equal and even, and the number of winding turns on the three output poles (4) of the stator tooth pole is 1 / 2 for each of the two groups of windings, so as to avoid vacant stator tooth poles on the stator, so that the magnetic field formed by the stator winding is completely evenly distributed on the outer circumference of the stator. Among them, the v-phase windings of the two groups are wound on one output pole and connected in parallel as the v-phase lead wire, the u-phase winding of one group and the w-phase winding of the other group are wound on another output pole, and the w-phase winding of one group and the u-phase winding of the other group are wound on the third On the output pole, two groups of u-phase windings are connected in parallel as u-phase lead-out wires, two groups of w-phase windings are connected in parallel as w-phase lead-out wires, and the w-phase, v-phase, and u-phase winding ends of each group of starting poles are connected by star point. The stator core (1) is provided with u-phase, v-phase, and w-phase terminal posts (8), and the u-phase, v-phase, and w-phase terminal posts (8) are adjacent to the three output poles (4) respectively. The v-phase lead-out wire is welded and fixed to the v-phase terminal post, the u-phase lead-out wire is welded and fixed to the u-phase terminal post, and the w-phase lead-out wire is welded and fixed to the w-phase terminal post.

2. The stator structure of the three-phase outer rotor motor according to claim 1, characterized in that: The number of turns wound on each stator tooth pole (2) is 14 turns, among which, on the 19th stator tooth pole, one group of u-phase windings is wound with 7 turns, and the other group of w-phase windings is wound with 7 turns, on the 20th stator tooth pole, one group of v-phase windings is wound with 7 turns, and the other group of v-phase windings is wound with 7 turns, and on the 21st stator tooth pole, one group of w-phase windings is wound with 7 turns, and the other group of u-phase windings is wound with 7 turns.

3. The stator structure of the three-phase outer rotor motor according to claim 1, characterized in that: In the two groups of three-phase windings, the u phase of one group starts from the 9th stator tooth pole and goes through the 6th and 3rd stator tooth poles to the 21st stator tooth pole in a clockwise direction. The v phase starts from the 8th stator tooth pole and goes through the 5th and 2nd stator tooth poles to the 20th stator tooth pole in a clockwise direction. The w phase starts from the 7th stator tooth pole and goes through the 4th and 1st stator tooth poles to the 19th stator tooth pole in a clockwise direction. The u-phase of a group starts from the 10th stator tooth pole and is wound in a counterclockwise direction through the 13th and 16th stator tooth poles to the 19th stator tooth pole. The v-phase starts from the 11th stator tooth pole and is wound in a counterclockwise direction through the 14th and 17th stator tooth poles to the 20th stator tooth pole. The w-phase starts from the 12th stator tooth pole and is wound in a clockwise direction through the 15th and 18th stator tooth poles to the 21st stator tooth pole.

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