KR102343297B1 - Permanent Magnet Synchronous Motor - Google Patents

Abstract

The present invention relates to a permanent magnet synchronous motor, and more particularly, to a permanent magnet synchronous motor capable of reducing iron loss, wherein the motor includes a housing and a stator installed in the housing and comprising a winding retainer including windings. ; and an inner rotor core coupled to a rotor shaft penetrating the housing and provided with a permanent magnet, an outer rotor fixing plate spaced apart from the inner rotor core at a predetermined distance and coupled to the rotor shaft, and the outer rotor It includes a rotor composed of an outer rotor core installed to face the permanent magnet at a predetermined distance to the fixed plate.

Description

Permanent Magnet Synchronous Motor

The present invention relates to a permanent magnet synchronous motor, and more particularly, to a permanent magnet synchronous motor capable of reducing iron loss.

A hybrid starter generator (HSG) is a device that is mechanically connected to an automobile engine and functions as a starter and a generator at the same time, and is also called an integrated starter generator (ISG).

The HSG enables a quick start by turning the crankshaft of the engine when starting a vehicle, charges a discharged battery through generator mode or regenerative braking while driving, and temporarily assists with engine torque during acceleration.

As a motor for HSG, a permanent magnet synchronous motor (PMSM), which has better performance than a field winding type motor or an induction machine, is mainly used.

The structure of a general PMSM is largely composed of a rotor and a stator. The rotor consists of a core using an electrical steel sheet and a permanent magnet attached or inserted into the core, and the stator consists of a core using an electrical steel sheet and windings.

Unlike non-permanent magnet devices, which only generate iron loss under load, PMSM always generates iron loss during rotation regardless of whether there is a load or not. Since the rotor of HSG is mechanically connected to the crankshaft and rotates together with the crankshaft, HSG using PMSM is always in a state in which iron loss is occurring unless the engine is stopped.

The iron loss generated in PMSM causes HSG heat and acts as a load on the engine, thereby lowering the system efficiency of the vehicle.

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KR 10-2011-0072192 A

Accordingly, the present invention is to solve the problems of the prior art as described above, and an object of the present invention is to provide a permanent magnet synchronous motor capable of reducing iron loss.

According to an embodiment of the present invention for achieving the above object, there is provided a permanent magnet synchronous motor comprising: a housing and a stator installed in the housing, the stator including a winding retainer including a winding; and an inner rotor core coupled to a rotor shaft penetrating the housing and provided with a permanent magnet, an outer rotor fixing plate spaced apart from the inner rotor core at a predetermined distance and coupled to the rotor shaft, and the outer rotor It includes a rotor composed of an outer rotor core installed to face the permanent magnet at a predetermined distance to the fixed plate.

Preferably, the winding retainer includes a plurality of grooves in which the windings are positioned.

The winding retainer includes a cylindrical inner portion and a plurality of extensions extending perpendicularly from the inner portion, wherein the windings are positioned between adjacent extensions.

The winding retainer further includes a fixing part extending vertically from the ends of the plurality of extension parts to both sides.

The winding retainer is formed of a non-magnetic, non-conductive material, and the inner rotor core is located within the winding retainer.

The housing includes openings respectively formed on opposite sides thereof, and the winding retainer is cylindrical, and is installed adjacent to one of the openings so as to be concentric with the openings inside the housing.

The outer rotor fixing plate has a disk shape, and the outer rotor core is formed vertically along an edge of the outer rotor fixing plate.

The outer rotor core consists of a plurality of core pieces arranged in a cylindrical shape.

A fixing groove into which the outer rotor core is inserted is formed in the outer rotor fixing plate, and it is located in the fixing groove and includes a spring located outside the outer rotor core.

An outer rotor retainer is provided on the outer rotor fixing plate, and the outer rotor core is provided on the outer rotor retainer.

A fixing groove into which the outer rotor retainer is inserted is formed in the outer rotor fixing plate, and it is located in the fixing groove and includes a spring located outside the outer rotor retainer.

Since the permanent magnet synchronous motor according to the present invention is a coreless type of a dual rotor type, it is possible to improve efficiency by reducing iron loss.

In addition, since the iron loss generated by the magnetic field due to the magnetism can be reduced close to zero, the efficiency can be improved, and the heat generated by the iron loss is reduced, so that the load on the cooling system can be reduced.

On the other hand, according to the present invention, as the rotational speed of the motor increases, the air gap increases and the electromotive force is reduced, so that the speed of the motor can be increased without using the field-weakening control in the constant output operation section. have.

1 is a combined cross-sectional view of a permanent magnet synchronous motor according to an embodiment of the present invention.
2 is a plan cross-sectional view of the synchronous motor in a stopped state of the permanent magnet synchronous motor according to an embodiment of the present invention;
3 is a plan cross-sectional view of the synchronous motor in the case of an operating state of the permanent magnet synchronous motor according to an embodiment of the present invention.
4 is a cross-sectional view of a stator of a permanent magnet synchronous motor according to an embodiment of the present invention.
5 is a detailed coupling plan view of a winding retainer and a winding of a stator of a permanent magnet synchronous motor according to an embodiment of the present invention.
6 is a combined cross-sectional view of a rotor of a permanent magnet synchronous motor according to an embodiment of the present invention.
7 is a flowchart illustrating a process of manufacturing a permanent magnet synchronous motor according to an embodiment of the present invention.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

In describing the embodiments of the present invention, if it is determined that a detailed description of a well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

Hereinafter, a permanent magnet synchronous motor according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a combined cross-sectional view of a permanent magnet synchronous motor according to an embodiment of the present invention, FIG. 2 is a plan cross-sectional view of the synchronous motor in a stopped state of the permanent magnet synchronous motor according to an embodiment of the present invention, and FIG. 3 is the present invention In the case of the operation state of the permanent magnet synchronous motor according to the embodiment of the synchronous motor is a plan sectional view.

Meanwhile, FIG. 4 is a cross-sectional view of a stator of a permanent magnet synchronous motor according to an embodiment of the present invention, and FIG. 5 is a detailed coupling plan view of a winding retainer and a winding of a stator of a permanent magnet synchronous motor according to an embodiment of the present invention, FIG. 6 is a cross-sectional view illustrating a coupling of a rotor of a permanent magnet synchronous motor according to an embodiment of the present invention.

1 to 6 , the permanent magnet synchronous motor 100 according to an embodiment of the present invention includes a stator 200 and a rotor 300 coupled to the stator 200, and the stator 200 is AC When a rotating magnetic field is formed by applying , the rotor 300 rotates accordingly. In this case, the permanent magnet synchronous motor 100 may be used for a hybrid starter generator (HSG).

The stator 200 may include a housing 210 , a winding retainer 230 , and a winding 250 .

The housing 210 forms the outer shape of the permanent magnet synchronous motor 100 , and may have a box shape having an inner space 211 , and opposite sides of the housing 210 may be coupled to the rotor 300 . Openings 212 and 213 are provided so as to In this case, the outer shape of the housing 210 may be formed in various ways, such as a cylindrical shape, a polygonal column shape, and the like.

The winding retainer 230 may have a cylindrical shape installed inside the housing 210 adjacent to one of the two openings 212 and 213 formed in the housing 210 . At this time, it is preferable that the center of the winding retainer 230 be installed to be concentric with the center of the openings 212 and 213 .

Meanwhile, the winding 250 is located in the winding retainer 230 , and it is preferable that a space in which the winding 250 is installed is provided in the winding retainer 230 so that the winding 250 can be stably fixed. .

Accordingly, a plurality of grooves are formed in the winding retainer 230 , and the winding 250 is positioned in the plurality of grooves formed in the winding retainer 230 .

For example, the winding retainer 230 may include a cylindrical inner portion 231 and a plurality of extension portions 233 extending vertically from the inner portion 231 . In this case, the extension portion 233 is preferably formed entirely along the length of the inner portion 231 , and the winding 250 is positioned between the adjacent extension portions 233 .

In addition, in order to prevent separation of the winding 250 , the winding retainer 230 may further include fixing portions 235 vertically extending from the ends of the plurality of extension portions 233 to both sides.

As such, since the winding retainer 230 has a structure without a stator core, a winding operation can be performed on the winding retainer 230 .

The winding retainer 230 is provided to be fixed in the housing 210 so that the winding 250 does not move by the magnetic force generated in the winding 250 and supports the weight of the winding 250 .

The winding retainer 230 is formed of a non-magnetic, non-conductive material so as not to affect magnetic flux flow, and may be formed of, for example, engineering plastic.

Accordingly, the iron loss of the permanent magnet synchronous motor mainly occurs in the stator core, and since the stator according to the present invention does not contain a magnetic material, the iron loss can be greatly reduced.

The rotor 300 includes a rotor shaft 310 , an inner rotor core 320 , a permanent magnet 330 , an outer rotor fixing plate 340 , an outer rotor core 350 , and a spring 360 . and an outer rotor retainer 370 and first and second bearings 380 and 390 may be further included.

The rotor shaft 310 is provided to pass through the stator 200 , and at this time, is provided to pass through the openings 212 and 213 of the housing 210 of the rotor 300 .

The inner rotor core 320 is provided in the stator 200 to surround the rotor shaft 310 , and the permanent magnet 330 is installed in the inner rotor core 320 . At this time, the inner rotor core 320 is located in the winding retainer 230 .

It is preferable that a plurality of the permanent magnets 330 are formed at predetermined intervals along the circumference of the inner rotor core 320 .

The outer rotor fixing plate 340 has a disk shape coupled to the rotor shaft 310 , and the outer rotor core 350 is provided at the edge of the outer rotor fixing plate 340 .

In this case, the outer rotor core 350 is vertically formed along the edge of the outer rotor fixing plate 340 , and is positioned opposite to the outside of the winding 250 of the stator 200 .

The outer rotor core 350 shields the magnetic flux generated from the magnet and the winding so as not to go outside, thereby preventing leakage of magnetic flux and creating a stable magnetic circuit.

In this case, the outer rotor core 350 may be formed in a single cylindrical shape, but as in this embodiment, the outer rotor core 350 is adjacent to each other along the edge of the outer rotor fixing plate 340 . It may be provided with a plurality of core pieces 351 forming a cylindrical shape.

That is, the outer rotor core 350 may be formed of a plurality of core pieces 351 arranged in a cylindrical shape.

3, when the outer rotor core 350 is composed of a plurality of divided core pieces 351, as the rotor 300 rotates, the plurality of core pieces 351 are subjected to centrifugal force. As it is tilted to the outside by the, the air gap α between the outer rotor core 350 and the winding 250 of the stator 200 increases, and the air gap α increases and the amount of magnetic flux linkage to the winding 250 is increased. and the electromotive force is reduced.

Table 1 below shows the electromotive force according to the increase in voids.

Gap (α) Increment (mm) electromotive force (V) 0 16.77 One 15.78 2 15.05 3 14.48 4 14.01 5 13.62

As can be seen in Table 1, as the air gap α between the outer rotor core 350 and the winding 250 of the stator 200 increases, the electromotive force decreases, and the air gap α increases by 5 mm. In this case, the electromotive force is reduced by 18.78%. Therefore, as the rotation speed of the rotor 300 increases, the air gap between the outer rotor core 350 and the winding 250 of the stator 200 increases and the electromotive force decreases. , it is possible to increase the speed of the rotor 300 without using the field-weakening control in the constant power operation section. Here, since the rotation speed of the rotor 300 means the rotation speed of the motor, constant power operation It is possible to increase the speed of the motor without using field-weakening control in the section.

On the other hand, a fixing groove (reference numeral not shown) for fixing the outer rotor core 350 is formed in the outer rotor fixing plate 340 , and the outer rotor core 350 is inserted into the fixing groove to be fixed. .

At this time, the outer rotor core 350 may be provided directly on the outer rotor fixing plate 340 , but the outer rotor retainer 370 is provided on the outer rotor fixing plate 340 as in the embodiment of the present invention. and the outer rotor retainer 370 may have a structure in which the outer rotor fixing plate 340 is provided.

Meanwhile, the spring 360 is provided on the outer rotor fixing plate 340 on the outside of the outer rotor core 350 .

At this time, when the fixing groove is formed in the outer rotor fixing plate 340 as in the present embodiment, it is preferable that the spring is also inserted into the fixing groove together with the outer rotor core 350 .

The spring 360 is configured to return the outer rotor core 350 tilted by centrifugal force to its original state, and may be, for example, a ring spring or a leaf spring.

That is, the spring 360 is compressed as the outer rotor core 350 is tilted by centrifugal force, and when the centrifugal force decreases or does not occur, it expands by the restoring force to restore the outer rotor core 350 to its original state. return to

On the other hand, when the outer rotor fixing plate 340 is provided on the outer rotor retainer 370 as in the present embodiment, the spring ( 360) is located in the fixing groove.

The first and second bearings 380 and 390 are positioned between the rotor shaft 310 and the housing 210 , and may be provided in a fixed form to the rotor shaft 310 .

As described above, the rotor according to the present invention has a structure that can form a stable magnetic circuit with only the rotor without a stator core, and since the outer and inner rotors rotate at the same speed, the change in magnetic field due to magnets in the outer and inner cores is reduced. Since it does not occur, it is possible to eliminate the iron loss occurring in the core.

Hereinafter, a process of manufacturing a permanent magnet synchronous motor according to an embodiment of the present invention will be briefly described.

7 is a flowchart illustrating a process of manufacturing a permanent magnet synchronous motor according to an embodiment of the present invention.

The permanent magnet synchronous motor according to the embodiment of the present invention may be manufactured by manufacturing the rotor assembly and the stator assembly, respectively, and then combining the rotor assembly with the stator assembly.

Referring to FIG. 7 , the rotor assembly manufactures the inner rotor core and inserts the permanent magnets (S510), connects the inner rotor core and the rotor shaft (S520), and the outer rotor core and the outer rotor fixing plate It can be manufactured through the process of manufacturing and fixing to the rotor shaft (S530), and attaching bearings to both ends of the rotor shaft (S540).

Meanwhile, the stator assembly may be manufactured by manufacturing a winding retainer (S550), performing winding on the winding retainer (S560), manufacturing a housing (S570), and fixing the winding retainer to the housing (S580). .

By combining the thus manufactured rotor assembly and the stator assembly (S590), the permanent magnet synchronous motor of the present invention can be manufactured.

On the other hand, although the permanent magnet synchronous motor according to the present invention has been described according to the embodiment, the scope of the present invention is not limited to a specific embodiment, and there are various It can be implemented with alternatives, modifications and changes of branches.

Therefore, the embodiments and the accompanying drawings described in the present invention are for explanation rather than limiting the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments and the accompanying drawings . The protection scope of the present invention should be construed by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: permanent magnet synchronous motor 200: stator
210: housing 230: winding retainer
250: winding 300: rotor
310: rotor shaft 320: inner rotor core
330: permanent magnet 340: outer rotor fixing plate
350: outer rotor core 360: spring
370: outer rotor retainer 380, 390: bearing

Claims (7)

a stator comprising a housing and a winding retainer installed in the housing and including windings; and
A rotor consisting of an inner rotor core having a permanent magnet installed therein while being coupled to a rotor shaft penetrating the housing inside the stator and an outer rotor core connected to rotate simultaneously with the rotor shaft from the outside of the stator; including,
The rotor includes a connecting portion that connects to each other so that the rotor shaft and the outer rotor core rotate at the same time,
The connection part is spaced apart from the inner rotor core by a predetermined interval, is coupled to the rotor shaft, and consists of an outer rotor fixing plate connected to the outer rotor core,
A fixing groove into which the outer rotor core is inserted is formed in the outer rotor fixing plate,
An outer side of the outer rotor core is elastically supported in the fixing groove, the outer rotor core is tilted outward according to an increase in centrifugal force according to the rotation of the rotor, and is restored when the centrifugal force is reduced, A spring is included so that the air gap formed between the rotor core and the winding of the stator varies according to the rotational speed of the rotor,
and a bearing positioned between the housing and the rotor shaft and fixed to the rotor shaft.
Permanent magnet synchronous motor characterized in that. delete delete The method according to claim 1,
The outer rotor fixing plate has a disk shape, and the outer rotor core is vertically formed along an edge of the outer rotor fixing plate. delete The method according to claim 1,
An outer rotor retainer is provided on the outer rotor fixing plate,
and the outer rotor core is provided in the outer rotor retainer. The method according to claim 1,
The outer rotor core is composed of a plurality of core pieces arranged in a cylindrical shape, and is positioned to face the permanent magnet at a predetermined distance.

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