High-speed permanent magnet motor for washing machine

Abstract

The utility model relates to a motor technology field for washing machine especially a kind of high-speed permanent-magnet motor for washing machine, including stator core, rotor core;The stator core has 12 stator slots, define outer diameter as OD, inner diameter as ID, its split ratio K1=ID / OD, and 0.6≤K1≤0.7;And / or the stator core has 12 first teeth, define first tooth width as W1, its first tooth diameter ratio K2=S*W1 / (π*ID), and 0.36≤K2≤0.46, wherein S is the stator slot quantity.The utility model gives the change relation of motor slot pole ratio, split ratio, tooth diameter ratio, yoke width, magnetic steel slot width, rib width and relevant performance from the angle of electromagnetic design, simultaneously also gives the stator tooth outer edge multi-segment line and rotor tooth outer edge multi-segment line structure design thought, to reach in promoting motor low-speed output torque, high-speed output power while, promote motor efficiency when low speed and high speed respectively, and the purpose of promoting motor anti demagnetization ability.

Description

Technical Field

[0001] This utility model relates to the field of motor technology for washing machines, and in particular to a high-speed permanent magnet motor for washing machines. Background Technology

[0002] Currently, drum washing machines use high-speed permanent magnet motors. During washing, the motor basically operates at around 580 rpm. The motor needs good torque output capability at low speeds, while during spin-drying, the motor needs to operate at a maximum of around 18,000 rpm. At high speeds, it needs good power output capability. Such a large range of operating speeds has brought great challenges to the design of the motor. Utility Model Content

[0003] The purpose of this invention is to improve the torque output capability of the motor at low speeds and the power output capability at high speeds, and to propose a high-speed permanent magnet motor for washing machines.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A high-speed permanent magnet motor for a washing machine, the motor comprising a stator core and a rotor core;

[0006] The stator core has 12 stator slots, with an outer diameter defined as OD and an inner diameter as ID. Its split ratio K1 = ID / OD, and 0.6 ≤ K1 ≤ 0.7.

[0007] And / or the stator core has 12 first teeth, the first tooth width is defined as W1, and its first tooth diameter ratio K2=S*W1 / (π*ID), and 0.36≤K2≤0.46, where S is the number of stator slots.

[0008] The rotor core includes 8 identical second teeth, with a magnetic slot formed between each pair of adjacent second teeth for placing magnets; and / or the outer edge of each second tooth is composed of multiple arc segments, with the number of arc segments being ≥3.

[0009] Define the width of the magnet slot as W3, and 6.5mm≤W3≤7.5mm.

[0010] The connection between the second tooth and the inner ring of the rotor core is defined as the rib width, and the rib width is defined as W4, where 0.6mm≤W4≤1.2mm.

[0011] The connection between two adjacent stator slots of the stator core is defined as the stator yoke, and the width of the stator yoke is W2, which satisfies 0.85≤W2 / W1≤0.95.

[0012] The first tooth edge of the stator core has a multi-segment structure, and the multi-segment is a line segment, an arc, or a combination of a line segment and an arc.

[0013] 100mm≤OD≤130mm.

[0014] Define the stator core height as H1, and 15mm≤H1≤45mm.

[0015] The stator core is composed of multiple stator laminations stacked together.

[0016] The rotor core is composed of multiple rotor laminations stacked together.

[0017] The present invention proposes a high-speed permanent magnet motor for washing machines, which has the following advantages: From the perspective of electromagnetic design, the present invention provides the relationship between parameters such as motor slot pole ratio, split ratio, tooth diameter ratio, yoke width, magnet slot width, and rib width and related performance. At the same time, it also provides the design ideas for multi-segment lines on the outer edge of stator teeth and multi-segment lines on the outer edge of rotor teeth, thereby achieving the purpose of improving the motor's low-speed output torque and high-speed output power, improving the motor's efficiency at low and high speeds respectively, and improving the motor's anti-demagnetization ability. Attached Figure Description

[0018] Figure 1 The parameters of this utility model are described below;

[0019] Figure 2 This is a graph showing the trend of the back electromotive force of this invention relative to K1;

[0020] Figure 3 This is a graph showing the changing trend between the linear inductance and K1 of this utility model;

[0021] Figure 4 This is a graph showing the trend of the output torque of this utility model relative to K2;

[0022] Figure 5 This is a graph showing the trend of iron loss in the tooth section and K2 in this utility model.

[0023] Figure 6 This is a graph showing the variation trend of the stator core modal frequency and W2 / W1 of this utility model;

[0024] Figure 7 This is a graph showing the trend of iron loss in the yoke of this utility model relative to W2 / W1;

[0025] Figure 8 This is a graph showing the trend of the demagnetization rate and W3 of this utility model.

[0026] Figure 9 This is a graph showing the trend of the change between the back electromotive force F and W4 in this utility model.

[0027] Figure 10 This is a schematic diagram of the three-segment arc of the stator tooth tip of this utility model;

[0028] Figure 11 This is a schematic diagram of the five-segment arc at the tip of the rotor tooth of this utility model. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0030] Reference Figures 1-11 A high-speed permanent magnet motor for washing machines, the motor including a stator core and a rotor core;

[0031] like Figure 1 As shown, the stator core has 12 stator slots, with the outer diameter defined as OD and the inner diameter as ID. The split ratio K1 = ID / OD, and 0.6 ≤ K1 ≤ 0.7. As an example, 100mm ≤ OD ≤ 130mm is used. The stator core height is defined as H1, and 15mm ≤ H1 ≤ 45mm is used.

[0032] The stator core has 12 first teeth, the width of which is defined as W1, and the ratio of its first tooth diameter to its first tooth diameter is K2 = S*W1 / (π*ID), and 0.36≤K2≤0.46, where S is the number of stator slots.

[0033] The rotor core includes 8 identical second teeth, with a magnetic slot formed between each pair of adjacent second teeth for placing magnets; and / or the outer edge of each second tooth is composed of multiple arc segments, with the number of arc segments being ≥3.

[0034] Define the width of the magnet slot as W3, and 6.5mm≤W3≤7.5mm.

[0035] This implementation uses a 12-slot, 8-pole configuration, with the denominator of the simplest fraction of the number of slots per pole per phase being 2, which can effectively reduce the content of fractional harmonics in the air gap magnetic field.

[0036] As one implementation method, such as Figure 2 and Figure 3 As shown, choosing 0.6≤K1≤0.65, a larger splitting ratio K1 can effectively increase the back EMF and winding line inductance of the motor, ensuring that the motor has a large torque output at low speeds, while also having a strong field weakening capability at high speeds.

[0037] As one implementation method, such as Figure 4 and Figure 5 As shown, choosing 0.36≤K2≤0.46, a larger tooth diameter ratio K2 can effectively reduce the saturation degree of stator tooth magnetic flux. At low speeds, under the same current, it can effectively increase the output torque of the motor. At the same time, at high speeds, it can also effectively reduce the iron loss of the motor teeth.

[0038] As one implementation method, such as Figure 6 and Figure 7 As shown, a larger yoke width W2 is selected with a value of 0.85≤W2 / W1≤0.95, which increases the stator core modal frequency while further reducing stator iron loss at high speeds.

[0039] As one implementation method, such as Figure 8 As shown, a width of 6.5mm≤W3≤7.5mm is selected. A larger magnet slot width can accommodate thicker magnets, which can effectively reduce the risk of magnet demagnetization.

[0040] As one implementation method, such as Figure 9 As shown, selecting a reasonable rib width of 0.6mm≤W4≤1.2mm can reduce the leakage flux content and increase the back EMF while ensuring rotor strength.

[0041] In one embodiment, such as Figure 10 As shown, the inner edge of the stator teeth adopts a three-segment structure, with the middle part being an arc 2, and the two sides being straight segments 1 and 3. Through reasonable design, the harmonic content in the air gap can be effectively reduced.

[0042] In one embodiment, such as Figure 11 As shown, the rotor teeth are designed with each tooth having an outer edge composed of five arc segments, including a first segment 3 in the middle, a second segment 3 and a third segment 4 symmetrically distributed on both sides of the first segment 3, a fourth segment 1 on one side of the second segment 3, and a fifth segment 5 on one side of the third segment 4. Through proper design, the harmonic content in the air gap can be effectively reduced.

[0043] In one implementation, the stator core is made of multiple stator laminations stacked together, or it is formed as a single piece.

[0044] The rotor core is made up of multiple rotor laminations stacked together, or it can be formed as a single piece.

[0045] This invention, from the perspective of electromagnetic design, presents the relationship between parameters such as motor slot pole ratio, split ratio, tooth diameter ratio, yoke width, magnet slot width, and rib width and related performance. It also provides design ideas for stator tooth outer edge multi-segment lines and rotor tooth outer edge multi-segment line structures, thereby achieving the goal of improving motor low-speed output torque and high-speed output power, while improving motor efficiency at low and high speeds, and enhancing motor anti-demagnetization capability.

[0046] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any technical solution, concept, or design obtained by those skilled in the art by making equivalent substitutions or changes based on the technical solution and utility model concept disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-speed permanent magnet motor for a washing machine, characterized in that, The motor includes a stator core and a rotor core; The stator core has 12 stator slots, with an outer diameter defined as OD and an inner diameter as ID. Its split ratio K1 = ID / OD, and 0.6 ≤ K1 ≤ 0.

7. The stator core has 12 first teeth, the width of which is defined as W1, and the first tooth diameter ratio K2 = S*W1 / (π*ID), and 0.36≤K2≤0.46, where S is the number of stator slots.

2. The high-speed permanent magnet motor for a washing machine according to claim 1, characterized in that, The rotor core includes 8 identical second teeth, with a magnetic slot formed between each pair of adjacent second teeth for placing magnets; and / or the outer edge of each second tooth is composed of multiple arc segments, with the number of arc segments being ≥3.

3. A high-speed permanent magnet motor for a washing machine according to claim 2, characterized in that, Define the width of the magnet slot as W3, and 6.5mm≤W3≤7.5mm.

4. A high-speed permanent magnet motor for a washing machine according to claim 2, characterized in that, The connection between the second tooth and the inner ring of the rotor core is defined as the rib width, and the rib width is defined as W4, where 0.6mm≤W4≤1.2mm.

5. A high-speed permanent magnet motor for a washing machine according to claim 1, 2, 3, or 4, characterized in that, The connection between two adjacent stator slots of the stator core is defined as the stator yoke, and the width of the stator yoke is W2, which satisfies 0.85≤W2 / W1≤0.

95.

6. A high-speed permanent magnet motor for a washing machine according to claim 1, 2, 3, or 4, characterized in that, The first tooth edge of the stator core has a multi-segment structure, and the multi-segment is a line segment, an arc, or a combination of a line segment and an arc.

7. A high-speed permanent magnet motor for a washing machine according to claim 1, 2, 3, or 4, characterized in that, 100mm≤OD≤130mm.

8. A high-speed permanent magnet motor for a washing machine according to claim 1, 2, 3, or 4, characterized in that, Define the stator core height as H1, and 15mm≤H1≤45mm.

9. A high-speed permanent magnet motor for a washing machine according to claim 1, 2, 3, or 4, characterized in that, The stator core is formed by stacking multiple stator laminations or by integral molding.

10. A high-speed permanent magnet motor for a washing machine according to claim 1, 2, 3, or 4, characterized in that, The rotor core is formed by stacking multiple rotor laminations or by integral molding.

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