WO2016183706A1

WO2016183706A1 - Three-phase variable frequency electric motor and washing machine

Info

Publication number: WO2016183706A1
Application number: PCT/CN2015/079014
Authority: WO
Inventors: 肖海泉; 高振刚; 迟闯
Original assignee: 佛山市威灵洗涤电机制造有限公司
Priority date: 2015-05-15
Filing date: 2015-05-15
Publication date: 2016-11-24

Abstract

The present invention is applicable to the field of electric motors, and discloses a three-phase variable frequency electric motor and a washing machine. The three-phase variable frequency electric motor comprises a stator assembly and a rotor assembly cooperated with the stator assembly, wherein the stator assembly comprises a stator iron core and a stator winding provided on the stator iron core, and the rotor assembly comprises a rotor iron core. The stator iron core has several stator teeth, and a stator slot is formed between any two adjacent stator teeth; the rotor iron core has several rotor teeth, and a rotor slot is formed between any two adjacent rotor teeth; the number of stator slots is 36, and the number of rotor slots is 48; and the rotor slots are oblique slots which are inclined in an axial direction of the rotor iron core. By optimizing the structure of the three-phrase variable frequency electric motor, the present invention effectively suppresses deleterious effects from the higher-order harmonics generated by a variable frequency driver to the noise, vibration and output features of the three-phase variable frequency electric motor, and successively solves the technical problems that the existing electric motor for a washing machine cannot satisfy the performance requirements of high efficiency and low noise.

Description

Three-phase inverter motor and washing machine

Technical field

The invention belongs to the field of electric machines, and in particular relates to a three-phase variable frequency motor for a washing machine and a washing machine therewith.

Background technique

As a commonly used household appliance, the washing machine has been widely used in people's lives. At present, the functions of the washing machine are relatively strong. For example, the user can select the corresponding washing program according to the type of load during use, and most of the current washing machines have water saving and power saving, high washing ratio, small damage to the clothes, and washing speed of the washing machine. Supports the adjustment from 400 to 1600 rpm, the water content is small after the dehydration of the clothes, and the drying time is short. However, with the continuous improvement of people's living standards, people choose the washing machine, in addition to pay attention to the functional characteristics of the washing machine, it will also pay attention to the vibration and noise performance of the washing machine. The vibration and noise performance of the washing machine is also often overlooked by the designers in the development of washing machines, so that the existing washing machine can not satisfy people's pursuit of high quality living standards.

The motor is an important component that affects the vibration and noise of the washing machine. The three-phase inverter motor for washing machine is a new type of three-phase asynchronous motor with variable frequency variable voltage. Because it needs to meet the design requirements that can be adjusted at various speeds, it is necessary to use a special variable frequency drive to drive the three-phase inverter motor. However, the voltage and current output of the variable frequency drive contain more harmonic components, and the frequency and voltage vary widely during operation. If the conventional three-phase asynchronous motor is still used, the design scheme of the near-slot and small groove of the stator and rotor is still adopted. (ie, the number of stator slots of the stator core is similar to the number of rotor slots of the rotor core, and both are relatively small), smooth torque characteristics and efficient motor performance will not be obtained, and serious problems will occur during the operation of the motor. The electromagnetic vibration and noise can not meet the design requirements of high efficiency and low noise of the motor for washing machine, which seriously affects the improvement of the comprehensive performance of the washing machine.

technical problem

The object of the present invention is to overcome the above-mentioned deficiencies of the prior art, and to provide a three-phase variable frequency motor and a washing machine, which solves the technical problem that the motor for the washing machine cannot meet the requirements of high efficiency and low noise performance.

Problem solution

Technical solution

In order to achieve the above object, the technical solution adopted by the present invention is: a three-phase variable frequency motor comprising a stator assembly and a rotor assembly mated with the stator assembly, the stator assembly including a stator core and a stator core a stator winding, the rotor assembly comprising a rotor core, the stator core having a plurality of stator teeth, and a stator slot formed between any two adjacent stator teeth, the rotor core having a plurality of rotor teeth a rotor slot is formed between any two adjacent rotor teeth, the number of slots of the stator slot is 36, the number of slots of the rotor slot is 48; and the rotor slot is along the rotor core A chute that is axially inclined.

Specifically, the slanting degree s=bs/t of the rotor is defined, and the slanting degree s of the rotor is 1.05 to 1.30, wherein bs is the axial end of the rotor slot along the rotor core The inclination distance of the outer circumference in the circumferential direction, t is the pitch of the stator teeth.

Preferably, the rotor has a chute s of 1.15.

Preferably, the stator winding is a three-phase symmetrical winding, and the number of poles of the stator winding is four poles.

Preferably, the rotor core is threaded and mounted on an inner side of the stator core.

Preferably, the tooth widths of the stator teeth are equal, and the tooth widths of the rotor teeth are equal.

Preferably, the rotor teeth have a tooth width of 2.4 ± 0.2 mm and the stator teeth have a tooth width of 3.4 ± 0.2 mm.

Preferably, the rotor core is laminated by a plurality of rotor punches.

Preferably, the stator core is laminated by a plurality of stator punches.

Advantageous effects of the invention

Beneficial effect

The three-phase variable frequency motor provided by the invention increases the number of stator slots and rotor slots, designs the number of rotor slots to be much more than the number of stator slots, and specifically verifies the stator slot and the rotor slot by simulation optimization design and prototype verification. The matching ratio is designed to be the optimum value of 36/48. At the same time, the rotor groove is designed as a chute which is inclined along the axial direction of the rotor core, so that the purpose of effectively optimizing the structure of the three-phase variable frequency motor can be achieved and suppressed. The high-order harmonics generated by the variable frequency drive have harmful effects on the noise, vibration and output characteristics of the three-phase inverter motor, which reduces the electromagnetic noise and electromagnetic vibration generated during the operation of the three-phase inverter motor, and avoids the three-phase inverter motor running. The phenomenon of electromagnetic noise that is easily perceived by the human ear is generated in the project, and the three-phase variable frequency motor is guaranteed to have a smooth output torque under high-speed operating conditions under high-speed operating conditions. The characteristics of the line speed improve the overall performance of the three-phase inverter motor, which satisfies the high-efficiency and low-noise design requirements of the three-phase inverter motor.

Further, the present invention also provides a washing machine having the above-described three-phase variable frequency motor.

The washing machine provided by the invention adopts the above-mentioned three-phase variable frequency motor, thereby effectively avoiding the electromagnetic noise which is easily perceived by the human ear in the operation process of the washing machine, and ensuring the output of the three-phase variable frequency motor under the low speed washing condition. Under the condition of smooth and high-speed dehydration conditions, the maximum dehydration speed is obtained, which can meet the demand of low-noise and small-vibration washing machines under the premise of ensuring the powerful washing function of the washing machine, and caters to people's high quality living standards. pursue.

Brief description of the drawing

DRAWINGS

1 is a schematic front view of a rotor core according to an embodiment of the present invention;

2 is a schematic left side view of a rotor core according to an embodiment of the present invention;

3 is a left side schematic view of a stator core according to an embodiment of the present invention;

4 is an exploded perspective view of a three-phase variable frequency motor and a controller according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of integrated assembly of a three-phase variable frequency motor and a controller according to an embodiment of the present invention. The invention

Invention embodiment

Embodiments of the invention

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It should be noted that when an element is referred to as being "fixed on" or "in" another element, it can be either directly on the other element or the central element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or a central element may be present.

It should also be noted that the left, right, upper, lower, top, bottom and other orientation terms in the following embodiments are only relative concepts or reference to the normal use state of the product, and should not be considered as having Restrictive.

As shown in FIG. 1 to FIG. 5, a three-phase variable frequency motor 1 according to an embodiment of the present invention includes a stator assembly 11 and a stator The subassembly 11 cooperates with a rotor assembly 12 including a stator core 111 and a stator winding 112 disposed on the stator core 111. The stator winding 112 may specifically be a coil winding, and the rotor assembly 12 includes a rotor core 121 and is disposed on The rotor winding 122 on the rotor core 121, the rotor winding 122 may specifically be a coil winding or a permanent magnet winding or a squirrel cage cast aluminum winding. The stator core 111 includes a stator yoke 1113 and a plurality of stator teeth spaced apart from the stator yoke 1113. 1111, and a stator slot 1112 is formed between any two adjacent stator teeth 1111. The rotor core 121 includes a rotor yoke 1213 and a plurality of rotor teeth 1211 spaced apart from the rotor yoke 1213, and any adjacent two rotor teeth 1211 A rotor slot 1212 is formed, the number of slots of the stator slot 1112 is 36, and the number of slots of the rotor slot 1212 is 48. The rotor slot 1212 is a slot that is inclined along the axial direction of the rotor core 121, that is, the rotor slot 1212 The axial side of the rotor core 121 extends obliquely toward the other axial side of the rotor core 121. The three-phase variable frequency motor 1 provided by the embodiment of the present invention designs the number of the rotor slots 1212 to be much more than the number of the stator slots 1112 by increasing the number of the stator slots 1112 and the rotor slots 1212, and specifically through simulation optimization design and prototype verification. The mixing ratio of the stator groove 1112 and the rotor groove 1212 is designed to be an optimum value of 36/48, and at the same time, the rotor groove 1212 is designed as a chute which is inclined along the axial direction of the rotor core 121, thereby achieving effective optimization. The purpose of the structure of the three-phase inverter motor 1 is to suppress the harmful effects of the higher harmonics generated by the variable frequency drive on the noise, vibration and output characteristics of the three-phase inverter motor 1, and reduce the electromagnetic generated during the operation of the three-phase inverter motor 1. The noise and electromagnetic vibration avoid the phenomenon that the three-phase inverter motor 1 generates electromagnetic noise that is easily perceived by the human ear in the operation process, and ensures that the three-phase inverter motor 1 outputs torque under smooth running conditions under low speed operation conditions. The characteristics of the maximum operating speed are obtained, and the overall performance of the three-phase variable frequency motor 1 is improved, which satisfies the design requirements of the three-phase variable frequency motor 1 with high efficiency and low noise.

Specifically, the slanting degree s=bs/t of the rotor is defined, and the slanting degree s of the rotor is 1.05 to 1.30, wherein bs is the inclination of the axial ends of the rotor groove 1212 along the circumferential direction of the outer circumference of the rotor core 121. The distance (ie, the projection distance of the rotor groove 1212 at the axial ends of the rotor core 121 in the circumferential direction of the rotor core 121), t is the pitch t of the stator teeth 1111 (ie, the same portion of the adjacent two stator teeth 1111) Distance between). After simulation optimization design and prototype verification, when the rotor slot s is designed to be between 1.05 and 1.30, the high-order harmonics generated by the variable frequency drive can be harmful to the noise, vibration and output characteristics of the three-phase inverter motor 1. The effect is relatively small, and the effect of reducing the electromagnetic noise and electromagnetic vibration of the three-phase variable frequency motor 1 is better.

More preferably, the rotor has a slot s of 1.15. After simulation optimization design and prototype verification, when the rotor slot s is designed to be 1.15, the high-order harmonics generated by the variable frequency drive can be made to the three-phase inverter motor. 1 noise The harmful effects caused by the sound, vibration and output characteristics are minimized, and the effect of reducing the electromagnetic noise and electromagnetic vibration of the three-phase inverter motor 1 is most remarkable.

Preferably, the stator windings 112 are three-phase symmetrical windings, and the number of poles of the stator windings 112 is four poles, so that the winding of the stator windings 112 can be facilitated, and the electromagnetic characteristics of the stator windings 112 can be ensured.

Preferably, as shown in FIG. 2 to FIG. 4, the rotor core 121 is mounted on the inner side of the stator core 111, that is, the three-phase inverter motor 1 provided in this embodiment is preferably an inner rotor motor, and thus the improvement is achieved. The high-efficiency performance of the phase-converter motor 1 and the low noise performance of the three-phase inverter motor 1 are remarkable, and can meet the design requirements of high-efficiency and low-noise of the three-phase inverter motor for washing machine. A shaft hole 1214 through which the rotating shaft 15 is bored is disposed at a central position of the rotor core 121. The shaft hole 1214 is specifically disposed through the rotor yoke 1213. The center of the stator core 111 is disposed through the rotor assembly 12 for penetration. An inner hole 1114 is provided, and the inner hole 1114 is specifically formed by enclosing the stator teeth 1111.

Preferably, the tooth widths tk2 of the stator teeth 1111 are equal, the tooth pitches t between the adjacent two stator teeth 1111 are equal, and the tooth widths tk1 of the rotor teeth 1211 are equal, and the adjacent two rotor teeth 1211 are equal. The pitches of the teeth are equal, so that the symmetry of the structure of the stator core 111 and the rotor core 121 can be ensured, and the manufacture of the stator core 111 and the rotor core 121 can be facilitated.

Preferably, the tooth width tk1 of the rotor tooth 1211 is 2.4±0.2 mm, and the tooth width tk2 of the stator tooth 1111 is 3.4±0.2 mm, so that the improved performance of the three-phase variable frequency motor 1 is improved and the three-phase variable frequency motor is reduced. The effect of low noise performance is remarkable. The stator tooth 1111 specifically includes a first tooth root 11111 and a first toothed shoe 11112. The first tooth root 11111 is located between the stator yoke 1113 and the first toothed shoe 11112. The tooth width tk2 of the stator tooth 1111 specifically refers to the first tooth root 11111. The projection width in the circumferential direction. The rotor tooth 1211 specifically includes a second root 12111 and a second toothed shoe 12112. The second root 12111 is located between the rotor yoke 1213 and the second toothed shoe 12112. The tooth width tk1 of the rotor tooth 1211 specifically refers to the second tooth root 12111. The projection width in the circumferential direction.

Preferably, both stator teeth 1111 and rotor teeth 1211 are parallel teeth. Specifically, each of the first roots 11111 has two first circumferential side walls disposed in a circumferentially opposite direction, and the two first circumferential side walls of the first root 11111 on each of the stator teeth 1111 are mutually Parallel; each of the second roots 12111 has two second circumferential side walls disposed in a circumferentially opposite direction, and the two first circumferential side walls of the second root 12111 on each of the rotor teeth 1211 are parallel to each other . Both the stator teeth 1111 and the rotor teeth 1211 are provided as parallel teeth, which are simple in structure and easy to manufacture.

Preferably, the rotor core 121 is formed by stacking a plurality of rotor punches along the axial direction of the rotor core 121. The sub-chips can be connected together by rivets. The rotor core 121 is formed by laminating a rotor punch, so that the tilting effect of the rotor groove 1212 is formed by lamination of the rotor punch, which is much simpler to manufacture than the integrally formed rotor core 121. And to ensure the molding quality of the rotor core 121.

Moreover, since the rotor punching piece can be integrally stamped and formed by the punching machine, the manufacturing process is very simple, the manufacturing efficiency is high, the manufacturing cost is low, and it is suitable for mass production, thereby simplifying the manufacturing process of the rotor core 121 and improving the rotor. The manufacturing efficiency of the iron core 121. The rotor punching piece can be specifically punched out from a silicon steel sheet, so as to facilitate the magnetic permeability of the rotor core 121 and reduce the processing cost of the rotor core 121.

Preferably, the stator core 111 is formed by stacking a plurality of stator punches along the axial direction of the stator core 111, and the stator punches can be connected together by rivets. Moreover, since the stator punching piece can be integrally stamped and formed by the punching machine, the manufacturing process is very simple, the manufacturing efficiency is high, the manufacturing cost is low, and the manufacturing process is suitable for mass production, thereby simplifying the manufacturing process of the stator core 111 and improving the stator. The manufacturing efficiency of the iron core 111. The stator punching piece can be specifically punched out from a silicon steel sheet, so as to facilitate the magnetic permeability of the stator core 111 and reduce the processing cost of the stator core 111.

Specifically, as shown in FIG. 4 and FIG. 5, the three-phase inverter motor 1 provided by the embodiment of the present invention further includes a front end cover 13, a rear end cover 14, a rotating shaft 15, a front bearing 16, and a rear bearing 17, a front end cover 13 and a rear end. The end caps 14 are respectively located on the axial sides of the stator assembly 11, and the rotor assembly 12 is fastened and mounted on the rotating shaft 15 and is mounted on the inner side of the stator assembly 11, and both ends of the rotating shaft 15 pass through the front bearing 16 and the rear bearing 17, respectively. Supported on the front end cover 13 and the rear end cover 14.

Further, the embodiment of the present invention further provides a washing machine having the above-described three-phase variable frequency motor 1. The washing machine provided by the embodiment of the invention adopts the three-phase variable frequency motor 1 described above, thereby effectively avoiding electromagnetic noise which is easily perceived by the human ear in the running process of the washing machine, and ensures that the three-phase variable frequency motor 1 is at a low speed washing machine. Under the condition that the output torque is smooth and the maximum dehydration speed is obtained under the high-speed dehydration condition, the demand for low noise and small vibration washing machine can be satisfied under the premise of ensuring the powerful washing function of the washing machine, and the people are high. The pursuit of quality living standards.

Further, as shown in FIG. 4 and FIG. 5, the washing machine further comprises a controller 2 for controlling the operation of the three-phase variable frequency motor 1, and the controller 2 is integrated with the three-phase variable frequency motor 1, that is, the controller 2 and the three phases The variable frequency motor 1 is assembled to form a module assembly, so that the controller 2 and the three-phase variable frequency motor 1 can be integrated as a whole The parts are in stock and installed, thereby facilitating reducing the size of the space occupied by the controller 2 and the three-phase variable frequency motor 1 in the washing machine, and facilitating quick disassembly and assembly of the controller 2 and the three-phase variable frequency motor 1 in the washing machine.

Specifically, as shown in FIGS. 4 and 5, the controller 2 is mounted on the rear end cover 14 of the three-phase inverter motor 1. The rear end cover 14 includes an end cover body 141 and mounting legs 142 protruding from the outer periphery of the end cap body 141. The controller 2 is mounted on a side of the end cap body 141 opposite to the stator assembly 11. The mounting foot 142 has a tangential plane 1421 facing the controller 2, and the arrangement of the tangential plane 1421 can reduce the interference of the mounting foot 142 on the mounting of the controller 2 on the rear end cover 14, so that the circuit board 21 of the controller 2 does not need to be The chamfer avoids the mounting leg 142, thereby maximizing the circuit board 21 that can be employed by the controller 2, sufficiently ensuring the wiring requirements of the board 21 of the controller 2.

Specifically, a mounting post (not shown) is disposed in the washing machine, and the three-phase inverter motor 1 is fastened to the mounting post by the mounting leg 142. As shown in FIG. 4 and FIG. 5, the mounting leg 142 is provided with an insertion hole 1422 for inserting a connection post (not shown) and an opening groove 1423 extending through the cutting plane 1421 toward the insertion hole 1422. The setting of the jack 1422 is mainly used for connecting with the mounting post on the washing machine to realize the mounting and fixing of the three-phase variable frequency motor 1 on the washing machine. The opening slot 1423 is disposed such that the socket 1422 has a certain expandability, that is, the mounting leg 142 has better elastic deformation performance at the opening groove 1423, so that although the cutting plane 1421 is disposed, the inner contour of the socket 1422 is provided. Less than the outline of the mounting post, however, the expandability of the receptacle 1422 allows the mounting post to be easily inserted into the receptacle 1422; and when the mounting post is inserted into the receptacle 1422, the resilient restoring force of the mounting foot 142 allows The inner wall of the socket 1422 can be closely attached to the outer wall of the mounting post, thereby ensuring the stable reliability of the mounting leg 142 to the mounting post. In this embodiment, through the arrangement of the opening slot 1423, the installation size of the three-phase inverter motor 1 and the controller 2 can be changed after the integrated design, that is, the size of the mounting column does not change, and the mounting post has multiple The relative position between the mounting posts also does not change, improving the versatility of the rear end cover 14.

Preferably, the outer contour of the mounting foot 142 is formed by enclosing the C-shaped curved surface and the tangential plane 1421, that is, the mounting foot 142 is equivalent to cutting the remaining portion by a cylinder with a tangential plane 1421. Specifically, the mounting post has a column shape, and the insertion hole 1422 is a cylindrical hole, so that the outer shape of the mounting leg 142 is formed by the C-shaped curved surface and the cutting plane 1421, which can ensure the uniformity of the wall thickness of the mounting leg 14212, and The structure is simple and easy to manufacture.

Specifically, as shown in FIGS. 4 and 5, the controller 2 includes a circuit board 21 and a shield 22, and the circuit board 21 is located between the end cap body 141 and the shield 22 along the axial direction of the end cap body 141. The shield 22 is preferably made of a waterproof material, which prevents direct exposure of the circuit board 21, thus ensuring the use of the controller 2 on the one hand. Electrical safety, on the other hand, can prevent impurities such as dust and moisture from invading the electronic components of the circuit board 21, effectively protecting the circuit board 21, and ensuring the service life of the controller 2.

The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

a three-phase variable frequency motor comprising a stator assembly and a rotor assembly mated with the stator assembly, the stator assembly including a stator core and a stator winding disposed on the stator core, the rotor assembly including a rotor core, The stator core has a plurality of stator teeth, and a stator slot is formed between any two adjacent stator teeth. The rotor core has a plurality of rotor teeth, and any adjacent two of the rotor teeth are formed. A rotor slot characterized in that: the number of slots of the stator slot is 36, the number of slots of the rotor slot is 48; and the rotor slot is a chute disposed obliquely along an axial direction of the rotor core.
The three-phase variable frequency motor according to claim 1, wherein the slanting degree s=bs/t of the rotor is defined, and the slanting degree s of the rotor is 1.05 to 1.30, wherein bs is the The axial ends of the rotor slots are inclined along the circumferential direction of the outer circumference of the rotor core, and t is the pitch of the stator teeth.
A three-phase variable frequency motor according to claim 2, wherein said rotor has a chute s of 1.15.
The three-phase variable frequency motor according to any one of claims 1 to 3, characterized in that the stator winding is a three-phase symmetrical winding, and the number of poles of the stator winding is four poles.
The three-phase inverter motor according to any one of claims 1 to 3, characterized in that the rotor core is threaded and mounted on the inner side of the stator core.
A three-phase variable frequency motor according to any one of claims 1 to 3, wherein each of said stator teeth has an equal tooth width, and each of said rotor teeth has an equal tooth width.
A three-phase variable frequency motor according to claim 6, wherein said rotor teeth have a tooth width of 2.4 ± 0.2 mm, and said stator teeth have a tooth width of 3.4 ± 0.2 mm.
The three-phase variable frequency motor according to any one of claims 1 to 3, characterized in that the rotor core is formed by laminating a plurality of rotor sheets.
The three-phase variable frequency motor according to any one of claims 1 to 3, characterized in that the stator core is formed by laminating a plurality of stator punches.
A washing machine characterized by comprising the three-phase variable frequency motor according to any one of claims 1 to 9.