A 7.5° step angle stepper motor

Abstract

The present invention relates to a 7.5° step angle stepper motor comprising windings, a rotor, and a stator. The rotor has 12 pairs of poles, and the stator is a split-type structure comprising an even number of identically shaped stator blocks. Each block has at least two stator teeth, and a stator yoke for winding is formed between adjacent stator teeth in each block. Compared with existing technologies, this invention significantly reduces the restrictions imposed by motor slot size on motor winding, thereby improving the utilization of the motor slot area.

Description

Technical Field

[0001] The present invention relates to a stepping motor, in particular to a stepping motor with a step angle of 7.5°. Background Art

[0002] The existing two-phase hybrid 7.5° step angle stepper motor structure is as follows Figure 1 and Figure 2 As shown, 1A and 1C are the stators of Scheme 1 and Scheme 2 respectively, and 2 is the rotor of the existing scheme. The rotor can be made of stacked stamping sheets or a permanent magnet rotor, but both are N and S alternating, with a total of 12 pairs of poles.

[0003] In the existing scheme 1, the stator has 8 main poles, namely A-phase main poles A1, A2, A3, A4 and B-phase main poles B1, B2, B3, B4. Each main pole has a stator tooth, for a total of 8 stator teeth TA1, TA2, TA3, TA4 and TB1, TB2, TB3, TB4. The 8 main poles are arranged in the order of A1, B1, A2, B2, A3, B3, A4, B4 in a counterclockwise direction, and the angles between them are 37.5°, 37.5°, 37.5°, 67.5°, 37.5°, 37.5°, 37.5°, 67.5°, respectively.

[0004] In the existing scheme 2, the stator has 8 main poles: A-phase main poles A1, A2, A3, A4, and B-phase main poles B1, B2, B3, B4. Each main pole has a stator tooth, for a total of 8 stator teeth: TA1, TA2, TA3, TA4, and TB1, TB2, TB3, TB4. The 8 main poles are arranged in the following counterclockwise order: A1, A2, B1, B2, A3, A4, B3, B4, with angles between them of 45°, 52.5°, 45°, 37.5°, 45°, 52.5°, 45°, and 37.5°, respectively.

[0005] There are two shortcomings in the existing solutions 1 and 2:

[0006] 1) The number of stator teeth is small, and the ratio of the number of stator teeth to the number of rotor pole pairs is low, resulting in a low overall output torque of the motor. In existing solutions 1 and 2, the number of stator teeth / rotor pole pairs is: 8 / 12 = 0.75.

[0007] 2) When the stator outer diameter is less than 20mm, the slot opening of the motor will be very small, which will cause difficulties in winding the motor. At the same time, because the winding is wound on the main pole of the motor, the space for the winding nozzle to enter and exit the slot will occupy the area inside the slot, affecting the motor slot fill rate and further affecting the output torque of the motor. Summary of the Invention

[0008] The purpose of the present invention is to provide a 7.5° step angle stepping motor in order to overcome the defects of the above-mentioned prior art.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] A 7.5° step angle stepper motor comprises a winding, a rotor and a stator. The rotor is provided with 12 pairs of poles. The stator is a split structure comprising an even number of stator blocks of identical shape. Each stator block is provided with at least two stator teeth. A stator yoke for winding is formed between adjacent stator teeth in each stator block.

[0011] Preferably, the outer diameter of the stator yoke is smaller than the outer diameter of the stator.

[0012] Preferably, the angle between adjacent stator blocks is 52.5° or 37.5°, the stator block is a structure with one end being wide and the other end being narrow, and the stator teeth are provided at the narrow end.

[0013] Preferably, there are four stator blocks, and each stator block is provided with two stator teeth, and the angle between the two stator teeth is 45°.

[0014] Preferably, in a counterclockwise direction, the four stator blocks are stator block 11, stator block 12, stator block 13 and stator block 14, and the angles between the stator blocks are 52.5°, 37.5°, 52.5° and 37.5°, respectively. Stator block 11 and stator block 13 belong to phase A, and stator block 12 and stator block 14 belong to phase B.

[0015] Preferably, in a counterclockwise direction, the stator teeth on the stator block 11 are TA1 and TA2, the stator teeth on the stator block 13 are TA3 and TA4, the stator teeth on the stator block 12 are TB1 and TB2, and the stator teeth on the stator block 14 are TB3 and TB4.

[0016] Stator yokes YA1, YA2, YB1 and YB2 are defined between the stator teeth TA1 and TA2, TA3 and TA4, TB1 and TB2, and TB3 and TB4 in sequence, and their thicknesses are LA1, LA2, LB1 and LB2, respectively, where LA1=LA2=LB1=LB2.

[0017] Preferably, there are two stator blocks, namely stator block 21 and stator block 22, wherein the stator block 21 is A-phase and the stator block 22 is B-phase. Each stator block has four stator teeth, and the angles between the two ends of the two stator blocks are 37.5° and 52.5°.

[0018] Preferably, in a clockwise direction, the stator teeth on the A-phase stator block 21 are TA1, TA2, TA3 and TA4, and the angles between the four stator teeth are 30°, 75° and 30°, respectively;

[0019] In clockwise direction, the stator teeth on the B-phase stator block 22 are TB1, TB2, TB3, and TB4, and the angles between the four stator teeth are 30°, 75°, and 30°, respectively;

[0020] The thicknesses of the stator yokes YA1, YA2, YA3, YB1, YB2, and YB3 formed between the stator teeth TA1 and TA2, TA3 and TA4, TA2 and TA3, TB3 and TB4, TB1 and TB2, and TB2 and TB3 are LA1, LA2, LA3, LB1, LB2, and LB3, respectively, where LA1=LA2=LB1=LB2, 1.0*LA1 <LA3=LB3<3.0*LA1。

[0021] Preferably, there are two stator blocks, namely stator block 31 and stator block 32, wherein the stator block 31 is phase A and the stator block 32 is phase B. Each stator block has six stator teeth, and the angles between the two ends of the two stator blocks are 37.5° and 52.5°, and the ratio of the number of stator teeth to the number of rotor poles is 1.

[0022] Preferably, in the counterclockwise direction, the stator teeth on the A-phase stator block 31 are TA1, TA2, TA5, TA6, TA3 and TA4, and the angles between the stator teeth are 30°, 30°, 15°, 30° and 30°, respectively;

[0023] The stator yokes formed between the stator teeth TA1 and TA2, TA2 and TA5, TA5 and TA6, TA6 and TA3, and TA3 and TA4 are YA1, YA3, YA5, YA4, and YA2, respectively. The stator yoke thicknesses are LA1, LA3, LA5, LA4, and LA2, respectively, where LA1 = LA2, LA3 = LA4, and 1.0 * LA1. <LA3<3.0*LA1,2.0*LA1<LA5<4.0*LA1。

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] (1) The core splitting and yoke winding technology of the present invention will greatly reduce the limitation of the motor slot size on the motor winding; at the same time, since the winding is done on the motor yoke, the entry and exit space of the winding nozzle will be in the radial direction, and will not occupy the area inside the motor slot, which is more conducive to improving the utilization rate of the motor slot area.

[0026] (2) The core splitting technology of the present invention is conducive to realizing modular winding production of motors and improving the production efficiency of motors.

[0027] (3) The present invention can increase the number of stator teeth of the motor stator, which is beneficial to improving the utilization rate of the motor magnetic field and increasing the output torque of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural diagram of the existing scheme 1;

[0029] Figure 2 This is a structural diagram of the existing scheme 2;

[0030] Figure 3 This is a schematic structural diagram of Example 1;

[0031] Figure 4 This is a schematic structural diagram of Example 2;

[0032] Figure 5 This is a structural diagram of Example 3. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0034] In order to increase the ratio of the number of stator teeth to the number of rotor pole pairs, reduce the difficulty of motor winding and improve the motor slot fill rate, the present invention adopts the following measures:

[0035] 1) While keeping the number of pole pairs unchanged, try to increase the number of stator teeth of the motor.

[0036] 2) The split core technology is adopted to greatly reduce the limitation of the motor slot size on the motor winding. At the same time, the motor winding is wound on the motor yoke, and the winding nozzle does not occupy the motor slot area, which increases the motor slot fill rate.

[0037] The 7.5° step angle stepper motor of the present invention includes windings, a rotor and a stator. The stator is a split structure, which includes an even number of stator blocks of the same shape. Each stator block is distributed with at least two stator teeth. A stator yoke for winding winding is formed between adjacent stator teeth in each stator block.

[0038] Example 1

[0039] like Figure 3As shown, the stator is divided into four stator blocks. All four stator blocks have the same structure, and each block has two stator teeth, with the angle between the two stator teeth being 45°. In a counterclockwise direction, the four stator blocks are stator block 11, stator block 12, stator block 13, and stator block 14, with the angles between the stator blocks being 52.5°, 37.5°, 52.5°, and 37.5°, respectively. Stator blocks 11 and 13 belong to phase A, while stator blocks 12 and 14 belong to phase B. The outer diameter of the stator yoke is smaller than that of the stator, and the stator blocks are H-shaped, with one end wider and the other narrower.

[0040] A stator yoke YA1, YA2, YB1 and YB2 is defined between two stator teeth of each stator block, and the thicknesses of the stator yokes are LA1, LA2, LB1 and LB2, respectively, wherein LA1=LA2=LB1=LB2.

[0041] During winding, the winding nozzle moves up and down the stator yoke from the slot opening. The nozzle's movement is radial, unlike circumferential winding on the teeth. This radial winding direction eliminates the need for slot space, improving the motor's slot fill rate. Furthermore, this stator block structure significantly improves winding efficiency.

[0042] Implementation 2

[0043] like Figure 4 As shown, the entire stator is divided into two blocks, a stator block 21 and a stator block 22. The two stators are identical, wherein the stator block 21 is for phase A and the stator block 22 is for phase B. Each stator block has four stator teeth, and the angles between the two ends of the two stator blocks are 37.5° and 52.5°.

[0044] In clockwise direction, the stator teeth on the A-phase stator block 21 are TA1, TA2, TA3, and TA4, and the angles between the four stator teeth are 30°, 75°, and 30°, respectively.

[0045] In clockwise direction, the stator teeth on the B-phase stator block 22 are TB1, TB2, TB3, and TB4, and the angles between the four stator teeth are 30°, 75°, and 30°, respectively.

[0046] Compared with Example 1, Example 2 adds new stator yoke parts YA3 and YB3, which means that new winding space is added, which is beneficial to improving the output torque of the motor.

[0047] In this embodiment, the thicknesses of the stator yokes YA1, YA2, YA3, YB1, YB2, and YB3 are LA1, LA2, LA3, LB1, LB2, and LB3, respectively (the thickness of the B-phase yoke is not indicated), where LA1 = LA2 = LB1 = LB2, and 1.0 * LA1 <LA3=LB3<3.0*LA1。

[0048] Example 3

[0049] like Figure 5 As shown, Example 3 is based on Example 2, with stator teeth TA5, TA6 and TB5, TB6 added between stator teeth TA2, TA3 and TB2, TB3 of the stator cores of phases A and B, respectively. The angles between the two ends of the two stator blocks are 37.5° and 52.5°.

[0050] After the stator teeth are added to the A and B two-phase stator blocks, the ratio of the number of stator teeth to the number of rotor poles of the motor is 12 / 12=1, which improves the utilization rate of the motor magnetic field and increases the output torque of the motor.

[0051] In Example 3, stator block 31 is identical to stator block 32. The stator teeth of phase A stator block are TA1, TA2, TA5, TA6, TA3, and TA4 in the counterclockwise direction, and the angles between the stator teeth are 30°, 30°, 15°, 30°, and 30°, respectively.

[0052] The yokes of the A-phase stator block in the counterclockwise direction are YA1, YA3, YA5, YA4, and YA2, and the corresponding yoke thicknesses are LA1, LA3, LA5, LA4, and LA2. LA1 = LA2, LA3 = LA4, and 1.0 * LA1 <LA3<3.0*LA1,2.0*LA1<LA5<4.0*LA1。

[0053] At the same time, coils can be wound on the stator yokes YA1, YA2, YA3, YA4, and YA5 (the winding portion of the stator yoke YA5 is not marked).

[0054] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A 7.5° step angle stepping motor, comprising a winding, a rotor and a stator, wherein the rotor has 12 pairs of poles, characterized in that: The stator is a split structure, which includes an even number of stator blocks of the same shape, each of which is provided with at least two stator teeth, and a stator yoke for winding is formed between adjacent stator teeth in each stator block; There are four stator blocks, and each stator block is provided with two stator teeth, and the angle between the two stator teeth is 45 degrees; In the counterclockwise direction, the four stator blocks are the first stator block (11), the second stator block (12), the third stator block (13) and the fourth stator block (14), and the angles between the stator blocks are 52.5°, 37.5°, 52.5° and 37.5°, respectively. The first stator block (11) and the third stator block (13) belong to the A phase, and the second stator block (12) and the fourth stator block (14) belong to the B phase. In a counterclockwise direction, the stator teeth on the first stator block (11) are TA1 and TA2 in sequence, the stator teeth on the third stator block (13) are TA3 and TA4 in sequence, the stator teeth on the second stator block (12) are TB1 and TB2 in sequence, and the stator teeth on the fourth stator block (14) are TB3 and TB4 in sequence; Stator yokes YA1, YA2, YB1 and YB2 are defined between the stator teeth TA1 and TA2, TA3 and TA4, TB1 and TB2, and TB3 and TB4 in sequence, and their thicknesses are LA1, LA2, LB1 and LB2, respectively, where LA1=LA2=LB1=LB2.

2. A 7.5° step angle stepper motor according to claim 1, characterized in that: The outer diameter of the stator yoke is smaller than the outer diameter of the stator.

3. A 7.5° step angle stepping motor, comprising a winding, a rotor and a stator, wherein the rotor has 12 pairs of poles, characterized in that: The stator is a split structure, which includes an even number of stator blocks of the same shape, each of which is provided with at least two stator teeth, and a stator yoke for winding is formed between adjacent stator teeth in each stator block; There are two stator blocks, namely a fifth stator block (21) and a sixth stator block (22), wherein the fifth stator block (21) is an A phase and the sixth stator block (22) is a B phase. Each stator block has four stator teeth, and the angles between the two ends of the two stator blocks are 37.5° and 52.5°. In clockwise direction, the stator teeth on the fifth stator block (21) of phase A are TA1, TA2, TA3 and TA4, and the angles between the four stator teeth are 30°, 75° and 30°, respectively; In clockwise direction, the stator teeth on the sixth stator block (22) of phase B are TB1, TB2, TB3 and TB4, and the angles between the four stator teeth are 30°, 75° and 30°, respectively; The thicknesses of the stator yokes YA1, YA2, YA3, YB1, YB2, and YB3 formed between the stator teeth TA1 and TA2, TA3 and TA4, TA2 and TA3, TB3 and TB4, TB1 and TB2, and TB2 and TB3 are LA1, LA2, LA3, LB1, LB2, and LB3, respectively, where LA1=LA2=LB1=LB2, 1.0*LA1 <LA3=LB3<3.0*LA1。 4. A 7.5° step angle stepping motor, comprising a winding, a rotor and a stator, wherein the rotor has 12 pairs of poles, characterized in that: The stator is a split structure, which includes an even number of stator blocks of the same shape, each of which is provided with at least two stator teeth, and a stator yoke for winding is formed between adjacent stator teeth in each stator block; There are two stator blocks, namely a seventh stator block (31) and an eighth stator block (32), wherein the seventh stator block (31) is an A phase and the eighth stator block (32) is a B phase. Each stator block has six stator teeth, and the angles between the two ends of the two stator blocks are 37.5° and 52.5°, respectively. The ratio of the number of stator teeth to the number of rotor poles is 1. In the counterclockwise direction, the stator teeth on the seventh stator block (31) of phase A are TA1, TA2, TA5, TA6, TA3 and TA4, and the angles between the stator teeth are 30°, 30°, 15°, 30° and 30°, respectively; The stator yokes formed between the stator teeth TA1 and TA2, TA2 and TA5, TA5 and TA6, TA6 and TA3, and TA3 and TA4 are YA1, YA3, YA5, YA4, and YA2, respectively. The stator yoke thicknesses are LA1, LA3, LA5, LA4, and LA2, respectively, where LA1 = LA2, LA3 = LA4, and 1.0 * LA1. <LA3<3.0*LA1,2.0*LA1<LA5<4.0*LA1。

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