CN1122348C - Stator for motor - Google Patents

Abstract

A motor stator for magnetic interaction with the motor rotor, comprising separate primary and secondary yokes. A primary yoke surrounds the rotor and includes a plurality of peripherally extending wall members and a plurality of radial wall members extending radially from the outer circumference of the peripherally extending wall members. The second yoke is cylindrical and disposed about the primary yoke and has an inner peripheral surface engaging the distal end of the radial wall member of the primary yoke. With this structure, the coil can be easily wound on the primary yoke of the stator, so that the motor can be assembled more efficiently. In addition, torque variations generated during operation of the motor are reduced, thereby reducing vibration and noise, thereby improving the performance of the motor.

Description

Stator for motor

technical field

This invention relates to an electrical machine comprising a stator and a rotor, and more particularly to an improved stator for such an electrical machine.

Background technique

Generally speaking, electric motors are used to convert electrical energy into mechanical energy. Such motors usually consist of a stator and a rotor. The stator contains an excitation coil that generates a magnetic force, and the rotor rotates within the stator by magnetic interaction with the magnetic force generated by the stator.

The present invention will be better understood by first understanding a conventional motor. Referring to FIGS. 7 and 8 , wherein FIG. 7 is an exploded perspective view of a stator and a rotor for a conventional motor, and FIG. 8 is a top plan view of the stator and rotor of FIG. 7 , the conventional motor includes a rotor 103 and surrounds the rotor 103 The stator 109.

The rotor 103 has a cylindrical shape and is made by stacking a plurality of chips (not shown). A hole or bore 105 is provided at the center of the rotor 103 for accommodating a rotating shaft (not shown) for transmitting the rotational force of the rotor 103 to, for example, a driven member (not shown). On the outer periphery of the rotor 103 are provided a plurality of permanent magnets 107 that generate a magnetic field for magnetic interaction with the stator 109 .

The stator 109 includes a columnar primary yoke 113 , a plurality of secondary yokes 111 radially extending equidistantly around the inner periphery of the primary yoke 113 , and excitation coils 117 wound on the secondary yokes 111 . Each secondary yoke 111 consists of a radial wall member 111a extending radially inward from the inner cylindrical surface of the primary yoke 113, and an annular or arcuate member 111b extending from the distal end of the radial member 111a. The ends extend outward. Arch 111b forms a discontinuous circle having the same center as primary yoke 113 but with a smaller inner diameter. The exciting coil 117 is wound vertically on the radial wall piece 111 a of the secondary yoke 111 .

With the motor described above, when the motor is energized by an external power source (not shown), a current flowing in the excitation coil 117 wound on the secondary yoke portion 111 of the stator 109 generates a magnetic field. As a result, since the plurality of secondary yoke portions 111 are arranged radially to form a circumference as described above, a rotating magnetic flux is generated. The rotor 103 of the motor rotates due to the rotating force generated by the rotating magnetic flux.

Fig. 9 is a schematic diagram of a torque distribution of a motor using a conventional stator as described above. Rotational sections were randomly selected and the graph represents the variation of torque during the occurrence of relative rotation in the selected rotating sections. Thus, the Y-axis in Figure 9 represents torque and the X-axis represents time.

FIG. 10 is a schematic diagram showing the distribution of the magnetic flux density of a conventional motor using the above-mentioned stator, in which the distribution of the magnetic flux density at a selected time during the rotation of the rotor 103 is shown. As shown, the x-axis represents the rotation angle and the y-axis represents the magnetic flux density. In the graph of FIG. 10, since the N- and S-poles of the permanent magnets 107 of the rotor 103 are alternately arranged, a negative (-) magnetic flux is shown. Fig. 10 actually shows the magnetic flux distributions of two different states represented by curve A and curve B. Curve A in FIG. 10 represents a normal state, and curve B represents a magnetized state. Both the normal state and the magnetized state are based on experiments performed using different shapes of magnets and different methods of mounting the magnets.

In the conventional motor described above, since the secondary yoke 111 extends (ie protrudes or protrudes) from the primary yoke 113 toward the rotor 103, only a limited space is provided. As a result, winding the excitation coil 117 on the secondary yoke 111 can be problematic. In addition, since the annular wall piece 111b of the secondary yoke portion 111 is integrally formed with the radial wall piece 111a, a bobbin cannot be used when winding the exciting coil 117.

In addition, since a gap is formed between the annular wall members 111b of the secondary yoke 111 in the shown conventional motor, the torque generated during the operation of the motor exhibits a wave shape, as shown in FIG. 9, where The magnitude of the moment of force fluctuates with time. In addition, as shown in FIG. 10 , the variation between the maximum value and the minimum value of the magnetic flux density is relatively large, and the magnetic flux density also frequently changes. Therefore, torque fluctuations in the motor output are also large, resulting in increased noise and vibration, and negatively affecting the working efficiency of the motor.

Contents of the invention

An object of the present invention is to provide a stator for an electric motor which can solve the above-mentioned problems, in particular, to provide a stator for an electric motor in which the exciting coil can be easily and reliably wound on the secondary yoke of the stator, wherein by The magnetic flux density generated by the excitation coil varies within a limited range.

In order to achieve these objects of the present invention, there is provided an electric machine comprising a rotor and a stator magnetically interacting with the rotor, wherein the stator comprises:

a primary yoke, in use, for surrounding the rotor of the electric machine and comprising a plurality of peripherally extending wall members, each having an outer surface and a plurality of radial wall members extending from the wall member An outer surface extends radially outward and includes a distal end.

a cylindrical secondary yoke disposed around the primary yoke, the secondary yoke being provided separately from the rotor yoke and having an inner circumference engaging the distal end of the radial wall member of the primary yoke surface; and

A plurality of excitation coils respectively wound on the radial wall members of the primary yoke.

Preferably, the stator further comprises a plurality of bobbins connected to the radial wall members of said primary yoke, the excitation coil being wound on the bobbins.

Preferably the primary yoke further comprises a plurality of connecting members between said peripherally extending wall members, whereby adjacent ones of said plurality of peripherally extending wall members are connected together by one of the connecting members, The connecting member is thinner than the peripherally extending wall members so as to form a recess between said adjacent wall members.

Preferably, an engagement groove is formed in one of (i) a distal end of said radial wall member of said primary yoke and (ii) an inner peripheral surface of said secondary yoke, and an engagement groove engaged with said engagement groove. An engagement protrusion is formed on the other of (i) the distal end of the radial wall member of the primary yoke and (ii) the inner peripheral surface of the secondary yoke.

According to another aspect of the invention, the electric machine used comprises a rotor, a stator magnetically interacting with the rotor, the stator comprising:

a primary yoke comprising a cylindrical member having an inner surface and a plurality of radial wall members extending inwardly from the inner peripheral surface of the cylindrical member and comprising a distal end;

a secondary yoke disposed concentrically within the interior of the primary yoke and comprising a plurality of annular wall members engaging the distal ends of the radial wall members of the primary yoke; and

A plurality of excitation coils are wound on the radial wall members of the primary yoke.

Preferably, the stator further comprises a plurality of bobbins connected to the radial wall members of the primary yoke, the excitation coils being wound on the bobbins.

Preferably, the secondary yoke further comprises a plurality of connecting parts between the annular wall parts, so that the connected wall parts of the plurality of annular wall parts are connected together by a connecting part, the connecting part is thinner than the annular wall parts, so that in A recess is formed between the adjacent wall pieces.

In a preferred embodiment, an engaging groove is formed at the distal end of each radial wall member of the primary yoke, and a plurality of engaging protrusions are formed on the outer peripheral surface of the secondary yoke, the engaging protrusions and the respective engaging grooves join.

In another preferred embodiment, a plurality of engaging grooves are formed in the outer peripheral surface of the secondary yoke, and engaging protrusions are formed on the distal end of each radial wall member of the primary yoke, each engaging protrusion being in contact with the each of the plurality of engaging grooves is engaged.

Other features and advantages of the present invention will be more clearly understood from the following detailed description of the preferred embodiments.

Description of drawings

Other advantages and objects of the present invention will be more clearly understood from the following detailed description of preferred embodiments with reference to the accompanying drawings.

1 is an exploded perspective view of a motor stator and rotor according to an embodiment of the present invention;

Figure 2 is a top view of the assembled stator and rotor of Figure 1;

3 is an exploded perspective view of a motor stator and rotor according to another embodiment of the present invention;

Figure 4 is a top view of the assembled stator and rotor in Figure 3;

Fig. 5 is a schematic diagram of the torque distribution of the motor using the stator of the present invention;

6 is a schematic diagram of different magnetic flux distributions of a motor using a stator according to the present invention;

Fig. 7 is the exploded schematic view of the stator and the rotor of the above-mentioned conventional motor;

Figure 8 is a top view of the stator and rotor assembled in Figure 7 as described above;

9 is a schematic diagram of the torque distribution of the motor using the conventional stator as described above;

FIG. 10 is a schematic diagram of a magnetic flux density distribution of a motor using a conventional stator as described above.

Detailed ways

1 and 2, wherein as shown above, FIG. 1 is an exploded perspective view of a stator and a rotor for a motor according to an embodiment of the present invention, and FIG. 2 is a top view of the assembled stator and rotor of FIG. 1, so The shown electric machine comprises a rotor 3 and a stator 9 surrounding the rotor 3 .

The rotor 3 is columnar and formed by stacking a plurality of chips (not shown). A hole or hole 5 is provided at the center of the rotor 3 for accommodating a rotating shaft (not shown) for transmitting the rotational force of the rotor 3 to, for example, a driven member (not shown). A plurality of permanent magnets 7 for magnetic interaction with the stator 9 are arranged on the outer periphery of the rotor 3 . In this embodiment, 12 permanent magnets are arranged in the form of columns, and their N poles and S poles are arranged alternately.

The stator 9 comprises a primary yoke or yoke portion 20 housing the rotor 3 and a cylindrically shaped secondary yoke or yoke portion 30 surrounding the primary yoke portion 20 . The primary yoke 20 includes a plurality of annularly extending wall members 21 arranged concentrically with respect to the secondary yoke 30, a plurality of radial wall members 23 extending or protruding outward from the outer peripheral surface of the wall member 21, and a plurality of connecting members 27 , which connect adjacent annular wall members and form a column together with the annular wall member 21 , and a plurality of projections or projections 25 formed at each outer end of the radial wall member 23 . The connecting piece 27 has a reduced thickness compared with the annular wall pieces 23 so that a recess 27 a is formed between adjacent annular wall pieces 21 . The recess 27a provides magnetic properties which ensure that the generated magnetic force is concentrated at the lateral ends of the annular wall member 27 .

On the inner periphery of the secondary yoke portion 30 , an engaging groove 31 for receiving the protrusion 25 is formed. The protrusions 25 are thinner than the radial wall members 23, and the width of the engagement groove 31 is adapted to receive each protrusion 25 therein.

As can be seen from FIG. 1 , a bobbin 29 is provided on the radial wall part 23 of the primary yoke 20 , and an excitation coil 28 for generating a magnetic force is wound on the bobbin 29 .

As described above, FIG. 3 is an exploded perspective view of a stator and a rotor for a motor according to another embodiment of the present invention, and FIG. 4 is a top view of the assembled stator and rotor of FIG. 3 . As shown, the stator 9 includes a generally cylindrical primary yoke or yoke portion 40 and a secondary yoke or yoke portion 50 disposed concentrically within the primary yoke portion 40 . The primary yoke 40 includes a cylindrical member 41, a radial wall member 43 extending radially from the inner periphery of the cylindrical member 41, and a protrusion or thinner than the radial wall member 43 formed on the inner end of the radial wall member 43. Protrusion 45.

The secondary yoke 50 includes a plurality of annular wall members 51 spaced apart along the periphery and connected together by a plurality of connecting members 53 formed between adjacent wall members 51 . On the outer periphery of the wall member 51, engaging grooves 51a are formed at positions corresponding to (ie, aligned with) the respective protrusions 45 of the primary yoke 40 for receiving these protrusions 45, respectively.

The connecting piece 53 of the secondary yoke 50 is thinner than the annular wall pieces 51 so that a recess 53 a is formed between the annular wall pieces 51 . As with the first embodiment of FIGS. 1 and 2 , the recess 53 a provides magnetic properties in which the magnetic force is concentrated at the lateral ends of the annular wall member 51 .

As shown in FIG. 3, bobbins 49 are provided on the radial wall member 43 of the primary yoke 40, and excitation coils 48 are wound on each bobbin 49 for generating a desired magnetic force.

In the embodiments of FIGS. 1 and 2 and FIGS. 3 and 4 , the bobbins 29 and 49 can be wound with excitation coils 28 and 48 respectively, which can then be mounted or fixed on the radial walls of the primary yokes 20 and 40 on pieces 23 and 43. As a result, the winding of the excitation coils 28 and 48 is very easy. In addition, when the primary yokes 20 and 40 are combined with the secondary yokes 30 and 50 , the protrusions 25 and 45 formed on the primary yokes 20 and 40 are engaged with the engaging grooves 31 and 50 of the secondary yokes 30 and 50 . 51 are engaged with each other, so that the whole combination is very firm.

Figure 5 shows a schematic diagram of the torque distribution of a motor employing the stator of the invention for randomly selected rotating parts. The curves show the variation of the torque generated in selected rotating parts for different times during the rotation. As shown, the y-axis represents the torque value generated for driving the motor, while the x-axis represents time.

Fig. 6 is a schematic diagram of the magnetic flux density distribution associated with a motor using a stator according to the present invention. The magnetic flux density distribution with respect to the position of the permanent magnets 7 surrounding the rotor 3 is shown for randomly selected times. As shown, the x-axis represents the rotation angle corresponding to the position of the permanent magnet 7, and the y-axis represents the magnetic flux density.

In FIG. 6, the magnetic flux density of one pole of the permanent magnet is represented as (+), and the magnetic flux density of the other pole is represented as (-). Curve A' in Fig. 6 represents a normal state, and curve B' therein represents a magnetized state, similar to curves A and B in Fig. 10 . Normal state and magnetized state were applied to experiments with different shapes of magnets and different mounting methods.

In the stator 9 according to the invention, the annular wall members 21 and 51 are integrally formed with the connection members 27 and 53 . As a result, no gaps are formed between the radial wall parts, so that so-called moment fluctuations are prevented. This is shown in FIG. 5 , where the torque varies smoothly over time, from which an optimum value for the torque can be derived as a function of the rotation time.

As shown in Figure 6, by using a stator according to the invention, the magnetic flux remains substantially constant with respect to the position of the permanent magnets.

The above-described embodiment is limited to the structure in which the bobbins 29 and 49 are combined with the radial wall members 23 and 43 after the excitation coils 28 and 48 are wound on the bobbins 29 and 49 . However, even when the excitation coils 28 and 48 are wound directly on the radial wall members 23 and 43, the problems associated with conventional motors can be overcome or reduced.

In the above embodiment, the protrusions 25 and 45 are formed on the radial wall members 23 and 43 , and the engagement grooves 31 and 51 a are formed on the secondary yoke portions 30 and 50 . However, it should be understood that the protrusions 25 and 45 may also be formed on the secondary yokes 30 and 50 , and the engagement grooves 31 and 51 a accommodating the protrusions may be formed on the radial wall members 23 and 43 . In addition, it is also possible to directly fit the primary yoke and the secondary yoke without using protrusions or engaging grooves.

It can be seen from the above description that the present invention can more easily wind the coil on the primary yoke of the stator of the present invention, and thus can assemble the motor more efficiently. At the same time, the best torque can be obtained. Since torque fluctuations are reduced, noise and fluctuations are substantially eliminated. As a result, the operating efficiency of the motor can be greatly improved compared with the motor using the above-mentioned conventional stator.

Although the present invention has been described in conjunction with preferred embodiments, it should be clear that for those skilled in the art, various changes and modifications made to it are within the spirit and scope of the present invention.

Claims (9)

1. one kind is used in and comprises a rotor, and the stator in motor with the mutual magnetic action stator of rotor is characterized in that described stator comprises:

A main yoke is used for the rotor around motor, and comprises the wall spares that a plurality of peripheries extend, and each all has an outer surface and a plurality of radially wall spare, and wall spare radially extends and comprises far-end from the outer surface outward radial of described wall spare.

The secondary yoke of a cylindricality is arranged to around described main yoke, and described secondary yoke and described main yoke provide separately, and has the inner circumferential surface with the distal engagement of the described radial wall spare of described main yoke; And

A plurality of excitation coils on a plurality of described radial wall spares that are wrapped in described main yoke respectively.

2. stator according to claim 1 is characterized in that, also comprises the bobbin that the radial wall spare of a plurality of and described main yoke links to each other, and excitation coil is wrapped on the described bobbin.

3. stator according to claim 1, it is characterized in that, described main yoke also comprises a plurality of connectors between the wall spare that described periphery extends, thereby the adjacent wall spare that described a plurality of periphery extends is joined together by one of them connector, described connector is thinner than peripheral wall extension spare, thereby forms recess between described adjacent wall spare.

4. stator according to claim 1, it is characterized in that, at the far-end of the described radial wall spare of (i) described main yoke with (ii) form engaging groove among in the inner periphery surface of described secondary yoke, the copulational protuberance that engages with described engaging groove be formed on (i) described main yoke described radial wall spare far-end and (ii) on the another one in the inner periphery surface of described secondary yoke.

5. one kind is used in and comprises a rotor, and the stator in motor with the mutual magnetic action stator of rotor is characterized in that described stator comprises:

A main yoke, it comprises a cylindrical member, and this cylindrical member has an inner surface and a plurality of radial wall spare that extends internally from the inner periphery surface of cylindrical member and comprises far-end;

A secondary yoke is arranged on the inside of described concentric main yoke, and comprises the wall spare of a plurality of annulars, and the annular wall part is with the distal engagement of the radial wall spare of described main yoke; And

A plurality of excitation coils are wrapped on the radial wall spare of described main yoke.

6. stator according to claim 5 is characterized in that, described stator also comprises the bobbin that the radial wall spare of a plurality of and described main yoke links to each other, and described excitation coil is wrapped on the bobbin.

7. stator according to claim 5, it is characterized in that, secondary yoke also comprises a plurality of connectors between described annular wall part, thereby the continuous wall spare of described a plurality of annular wall parts is connected in together, described connector is thinner than described annular wall part, thereby forms recess between described adjacent wall spare.

8. stator according to claim 5, it is characterized in that, form an engaging groove in the far-end of each described radial wall spare of described main yoke, and a plurality of copulational protuberance is formed on the outer periphery surface of described secondary yoke, described copulational protuberance engages with described each engaging groove.

9. stator according to claim 5, it is characterized in that, form a plurality of engaging grooves in the outer periphery surface of described secondary yoke, form copulational protuberance on the far-end of each described radial wall spare of main yoke, each copulational protuberance all engages with each engaging groove of described a plurality of engaging grooves.

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