TWI385899B - Rotor structure for permanent-magnet machines and manufacture method thereof - Google Patents

Description

Rotor structure of permanent magnet motor and manufacturing method thereof

The present invention relates to a rotor structure of a permanent magnet type motor and a method of manufacturing the same, and more particularly to a rotor structure having a joint member formed by a single low magnetic permeability material integrally formed.

In general, the rotor of a conventional permanent magnet motor has a rotating shaft and a magnet member, wherein the magnet member is disposed on a radially outer surface of the rotating shaft and has a plurality of magnetic poles, and the plurality of magnetic poles are oriented toward the permanent Several coils of the stator of a magnetic motor. Thereby, when the plurality of coils introduce a plurality of currents to generate an alternating magnetic field, the purpose of rotating the rotor can be achieved by utilizing the repulsive or attracting magnetic force between the alternating magnetic field and the magnetic pole of the magnet member. However, since the magnetic field lines generated by the magnetic poles of such conventional rotor structures are not uniformly distributed between the rotor and the stator, it is easy to generate a large torque (Cogging Torque) when the rotor rotates. This torque will cause the permanent magnet type motor to easily generate vibration and noise during operation. In addition, since the closed magnetic circuit formed by the magnetic lines of force passes through the rotating shaft, the rotating shaft must use a material having high magnetic permeability; however, since the material generally having high magnetic permeability is a conductive material, the rotating shaft is When the magnetic field line is passed, the rotating shaft forms a current loop on the tangential plane perpendicular to the magnetic line of force to cause thermal energy loss, which is called "Eddy Current loss".

Regarding the shortcomings such as the large torque and the eddy current loss of the conventional permanent magnet type motor, several conventional methods have been proposed for improving the rotor of the permanent magnet type motor to improve the performance, reduce the running noise, and prolong the use. Life and other purposes. For example, the mutually insulated silicon steel sheets are stacked along the axial direction of the rotating shaft to form a portion of the rotating shaft passing through the magnet member, thereby reducing the eddy current loss formed in the rotating shaft. In addition, as disclosed in U.S. Patent No. 6,703,746, entitled "Interior Permanent Magnet Rotor", a plurality of magnetic line paths are preset in a rotor, and a plurality of grooves are formed in the path of the magnetic lines of force. a groove for filling a high magnetic energy material near the outer circumferential surface of the stator, and filling a low magnetic energy material in the remaining space of the groove, and then magnetizing the rotor, thereby The path of the magnetic field lines within the rotor is planned such that it does not pass through the shaft of the rotor. Wherein, the high and low magnetic energy materials are filled in the liquid form and then solidified in order to facilitate the manufacture of the stator and avoid the excessively uneven magnetic field distribution state of the stator surface due to the slot gap, thereby simultaneously achieving a reduction in the magnetic field. The effect of torque and eddy current loss. However, both of the above solutions make the structure of the rotor too complicated, which causes the rotor to be manufactured in an extremely cumbersome procedure and manner, resulting in disadvantages such as difficulty in mass production and lengthy process. For the above reasons, it is necessary to further improve the rotor structure of the conventional permanent magnet type motor described above.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide a rotor structure for a permanent magnet type motor that is cost effective and easy to assemble and mass produce.

In order to achieve the foregoing object, the technical means and the achievable effects of the present invention include: a permanent magnet type motor rotor structure including a permanent magnetic ring and a joint member, the permanent magnet The ring has a passage extending along the axial direction of the permanent magnetic ring, and the coupling member is fixed to the permanent magnetic ring, and the coupling member is made of a material having low magnetic permeability. Wherein, the permanent magnetic ring has an even number of magnetic poles, and the path of the magnetic lines formed by the magnetic poles forms a Halbach array. Thereby, the core made of the material with low magnetic permeability and the permanent magnetic ring forming the Halbach array can achieve the functions of simplifying the process, reducing the structural complexity and manufacturing cost.

The joint of the rotor structure is made in an integrally formed manner, thereby further simplifying the process and reducing the structural complexity.

In addition, the manufacturing method of the rotor structure of the permanent magnet type motor of the present invention comprises: magnetizing a magnetizer of a magnetizer to make each magnet become an N pole magnet, an interpole magnet or an S pole magnet; Combining each of the magnets with at least one interpole magnet between an N-pole magnet and an S-pole magnet to form a permanent magnetic ring having a Halbach array; forming a low magnetic permeability material A coupling member is attached to the permanent magnet ring. Thereby, the rotor structure having the above-described effects can be constructed by a simple process.

The above and other objects, features, and advantages of the invention will be apparent from the description of the appended claims.

Please refer to FIGS. 1 and 2, which are respectively a combined and exploded perspective view of the rotor structure of the permanent magnet type motor according to the first embodiment of the present invention. The rotor structure of the first embodiment of the present invention comprises a permanent magnetic ring 1 and a bonding member 2, wherein the permanent magnetic ring 1 is formed by a magnetization process by a magnetizable magnetic energy material [Magnetic Energy Material], that is, The magnetic energy material may be selected from any material that can constitute a magnetic material, wherein the permanent magnetic ring 1 is composed of a plurality of magnets 12 surrounding a channel 11, and the channel 11 and the magnet 12 are respectively along the permanent magnetic ring 1. In the first embodiment, the coupling member 2 is a rotating shaft, and the rotating shaft has a core portion 21 and two end portions 22, and the core portion 21 is threaded through the passage fixed to the permanent magnetic ring 1. 11. The two end portions 22 respectively form the two ends of the rotor structure in the axial direction. Thereby, the rotor structure of the first embodiment of the present invention can be applied to any conventional inner rotor type permanent magnet type motor, wherein the permanent magnetic ring 1 is provided for one of the stators of the radial permanent magnet type motor [not drawn Inductively, the end portion 22 of the coupling member 2 is rotatably coupled to the housing of the radial permanent magnet motor (not shown).

Please refer to FIGS. 3a and 3b, which are schematic diagrams showing the actual internal magnetic circuit and the ideal internal magnetic circuit of the permanent magnetic ring 1 according to the first embodiment of the present invention. The permanent magnetic ring 1 has an even number of magnetic poles, and the magnetic poles of the permanent magnetic ring 1 are intended to form a path of magnetic lines of force a as shown in FIG. 3b to form an inner rotor type Halbach Array, wherein The permanent magnet ring 1 preferably has four magnetic poles as shown in Figures 3a and 3b. In the process of forming the permanent magnetic ring 1, the magnets 12 are respectively magnetized by a magnetizer, so that the magnets 12 become an N-pole magnet 121 and an inter-pole magnet according to the direction of the internal magnetic field. 122 or an S-pole magnet 123, and each of the magnets 12 is combined with an N-pole magnet 121 and an S-pole magnet 123 to form at least one inter-pole magnet 122, and the inner rotor type Halbach is formed. The permanent magnetic ring of the array 1. In detail, the internal magnetic field direction of each of the N-pole magnets 121 extends from the radially inner surface of the permanent magnet ring 1 toward the radially outer surface of the permanent magnet ring 1, and forms a permanent magnetic ring on the radially outer surface. One of the N poles; the internal magnetic field direction of each of the interpole magnets 122 extends from the S pole magnet 123 toward the N pole magnet 121; the internal magnetic field direction of each of the S pole magnets 123 is determined by the diameter of the permanent magnet ring 1 An outward surface extends toward a radially inner surface of the permanent magnet ring 1 and an S pole of the permanent magnet ring 1 is formed on the radially outer surface. Thereby, when the permanent magnet ring 1 is formed in combination with each of the magnets 12, the direction of the internal magnetic field of the permanent magnet ring 1 can be approximated by an inner rotor type Halbach array having a path of magnetic lines of force as shown in Fig. 3b. The magnetic flux line a distributed in this form can not only greatly increase the magnetic flux density formed by the magnetic pole of the permanent magnetic ring 1 on the outer circumferential surface of the permanent magnetic ring 1, but also increase the magnetic flux passing through the stator coil of the permanent magnet motor, and The magnetic lines of force formed in the passage 11 of the permanent magnet ring 1 can be greatly reduced. Further, the permanent magnet ring 1 of the rotor structure of the present invention can also effectively reduce the torsional torque, thereby reducing vibration and noise generated during operation.

On the other hand, since the path of the magnetic force line a of the permanent magnet ring 1 of the present invention is planned to be the inner rotor type Halbach array, the core portion 21 of the joint member 2 can be made of a material having low magnetic permeability. Thus, even the joint member 2 is integrally formed of such a material having low magnetic permeability by integral molding. More specifically, the joint member 2 can be integrally formed from stainless steel having excellent rigidity, so that the rotor structure of the present invention has the advantages of structural and process simplification, structural strength and service life, and can also be The manufacturing cost is reduced. In addition, the bonding member 2 can also be made of a non-metallic material with high temperature resistance, good wear resistance and high strength, such as PEEK, POM or PA6/66 in engineering plastics, etc., so as to be manufactured by injection molding. The component 2 is combined to further simplify the process.

Referring to Fig. 4, it is an exploded perspective view showing the structure of the rotor of the permanent magnet type motor according to the second embodiment of the present invention. Compared with the first embodiment of the present invention, the permanent magnetic ring 1' in this embodiment also has a channel 11' extending along the axial direction of the permanent magnetic ring 1', but the internal magnetic field direction is similar to that formed. Figure 5b shows the path of the magnetic field line b of the outer rotor type Halbach array. In addition, the coupling member 2 ′ in the embodiment is a hub having a ring wall portion 23 and a shaft portion 24 , and the outer peripheral surface of the permanent magnet ring 1 ′ is fixedly coupled to the inner circumference of the ring wall portion 23 . The shaft portion 24 extends into the passage 11' of the permanent magnet ring 1', and an accommodation space is formed between the shaft portion 24 and the inner peripheral surface forming the passage 11'. Accordingly, the rotor structure of the second embodiment of the present invention can be applied to any conventional rotor-type radial permanent magnet motor, wherein the space between the permanent magnet ring 1' and the shaft portion 24 is provided. A stator (not shown) of the radial permanent magnet motor is accommodated, and the shaft portion 24 of the joint member 2' is rotatably coupled to the casing of the radial permanent magnet motor. Painted]. Further, the permanent magnetic ring 1' is also constituted by a plurality of magnets 12' extending in the axial direction thereof.

Referring to FIGS. 5a and 5b again, in the process of forming the permanent magnetic ring 1', the magnet 12' is formed after the magnets 12' are magnetized by the magnetizer. The N-pole magnet 121', the inter-pole magnet 122' and the S-pole magnet 123' may together constitute a permanent magnetic ring 1' of the outer rotor type Halbach array [ie, the N-pole magnet 121' has an N-pole formed therein The wall surface of the passage 11' of the permanent magnet ring 1'; and the S pole magnet 123' has a wall formed on the wall 11' of the permanent magnet ring 1'], and the other steps are the first to manufacture the present invention. The steps of the permanent magnetic ring 1 of the embodiment are the same. Thereby, when the permanent magnet ring 1' is formed in combination with each of the magnets 12', the direction of the internal magnetic field of the permanent magnet ring 1' can be approximated by the outer rotor type of Hal with the path of the magnetic force line b as shown in FIG. 5b. Bach array, and the magnetic flux b distributed in this form can not only effectively increase the magnetic flux density formed by the magnetic pole of the permanent magnetic ring 1' in the channel 11' of the permanent magnetic ring 1', and can greatly reduce the permanent magnetic field. The magnetic lines of force formed on the outer surface of the ring 1', so that the ring wall portion 23 of the joint member 2' can be made of the material having low magnetic permeability as described above, and even the joint member 2' can have a low overall The magnetically conductive material is formed by integral molding.

In summary, the rotor structure of the permanent magnet type motor has a large torque and eddy current loss, or has the disadvantages of complicated structure and manufacturing procedures, because the permanent magnetic ring 1, 1' of the present invention has Magnetic lines a, b in the form of an outer rotor or inner rotor type of Halbach array, such that the rotor structure can provide a larger magnetic flux density and reduce the torsional torque, and more because of the permanent magnetic ring 1, 1 ' The magnetic lines a and b are distributed such that the core portion 21 or the ring wall portion 23 of the joint member 2, 2' can be constructed by using the low magnetic permeability material, thereby effectively reducing the eddy current loss in the core portion 21 or the annular wall portion 23. And magnetic hysteresis loss, and even the non-metallic material can be used to manufacture the joint parts 2, 2', so as to avoid the two energy loss, reduce the manufacturing cost and simplify the process.

While the present invention has been disclosed in its preferred embodiments, the invention is not intended to limit the invention, and the invention may be variously modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

1. . . Permanent magnetic ring

1'. . . Permanent magnetic ring

11. . . aisle

11’. . . aisle

12. . . magnet

12’. . . magnet

121. . . N-pole magnet

121’. . . N-pole magnet

122. . . Interpole magnet

122’. . . Interpole magnet

123. . . S pole magnet

123’. . . S pole magnet

2. . . Joint piece

2'. . . Joint piece

twenty one. . . Core

twenty two. . . Ends

twenty three. . . Ring wall

twenty four. . . Shaft

Fig. 1 is a perspective view showing the assembly of a rotor structure of a permanent magnet type motor according to a first embodiment of the present invention.

Fig. 2 is an exploded perspective view showing the structure of a rotor of a permanent magnet type motor according to a first embodiment of the present invention.

Fig. 3a is a view showing the internal magnetic circuit of the permanent magnetic ring of the rotor structure of the permanent magnet type motor according to the first embodiment of the present invention.

Fig. 3b is a schematic view showing an ideal internal magnetic circuit of a permanent magnetic ring of a rotor structure of a permanent magnet type motor according to a first embodiment of the present invention.

Fig. 4 is an exploded perspective view showing the structure of a rotor of a permanent magnet type motor according to a second embodiment of the present invention.

Fig. 5a is a schematic view showing the internal magnetic circuit of the permanent magnetic ring of the rotor structure of the permanent magnet type motor according to the second embodiment of the present invention.

Fig. 5b is a schematic view showing an ideal internal magnetic circuit of a permanent magnetic ring of a rotor structure of a permanent magnet type motor according to a second embodiment of the present invention.

1. . . Permanent magnetic ring

11. . . aisle

2. . . Rotating shaft

twenty one. . . Core

twenty two. . . Ends

Claims (8)

A rotor structure of a permanent magnet type motor, comprising: a permanent magnetic ring having a passage extending along an axial direction of the permanent magnetic ring; a coupling member coupled to fix the permanent magnetic ring, and the coupling member has The material of low magnetic permeability; wherein the permanent magnetic ring has an even number of magnetic poles, and the path of the magnetic lines formed by the magnetic poles forms a Halbach array. The rotor structure of the permanent magnet type motor according to claim 1, wherein the permanent magnet ring comprises a plurality of magnets respectively extending along an axial direction of the permanent magnet ring. The rotor structure of the permanent magnet type motor according to claim 1, wherein the joint member is made of the material having low magnetic permeability in an integrally formed manner. The rotor structure of the permanent magnet type motor according to claim 1, wherein the coupling member has a core portion penetrating the passage fixed to the permanent magnetic ring, and the path of the magnetic lines formed by the magnetic pole The resulting Halbach array is an inner rotor type Halbach array. The rotor structure of the permanent magnet type motor according to the first aspect of the invention, wherein the joint member has a ring wall portion, and an outer peripheral surface of the permanent magnet ring is fixedly coupled to an inner circumferential surface of the ring wall portion, and the magnetic pole portion The Halbach array formed by the path of the formed magnetic lines is an outer rotor type Halbach array. The rotor structure of the permanent magnet type motor according to claim 1, wherein the material having low magnetic permeability is stainless steel. The rotor structure of the permanent magnet type motor according to claim 1, wherein the material having low magnetic permeability is a non-metal material. A method for manufacturing a rotor structure of a permanent magnet type motor, comprising: magnetizing a plurality of magnets by a magnetizer to make each of the magnets an N-pole magnet, an inter-pole magnet or an S-pole magnet; The magnet is combined with an N-pole magnet and an S-pole magnet to sandwich at least one interpole magnet to form a permanent magnetic ring having a Halbach array; and a combination of a low magnetic permeability material And fixing the permanent magnetic ring to the joint.