JP2932881B2 - Electric motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor in which a stator core is divided into a magnetic pole core and an outer race core.

[0002]

2. Description of the Related Art Generally, in a stator core of a motor, when a magnetic pole portion and an outer ring portion are integrally formed, when the magnetic pole portion is wound, the outer ring portion hinders the operation of winding. An example of the stator core that has prevented such a complicated winding operation is disclosed in Japanese Patent Application Laid-Open No. 58-33945.

[0003] The stator core disclosed in this publication has a structure in which a magnetic pole core and an outer race core are formed separately, and after winding the magnetic pole core, the magnetic pole core is coupled to the outer race core. The magnetic pole core is formed in a substantially cylindrical shape,
Winding teeth were provided on the outer periphery of the cylindrical portion made of a thin plate. Further, the outer race core was also formed in a substantially cylindrical shape, and a concave portion into which the teeth of the magnetic pole core were fitted was provided on the inner peripheral portion.

That is, to assemble a stator core,
After winding the magnetic pole core, the teeth are fitted into the concave portions and the magnetic pole core is inserted into the outer race core.

[0005]

However, as described above, in the electric motor in which the magnetic pole core and the outer race core are connected to each other to form a stator core, the magnetic pole core is connected to the inner diameter side through a thin wall or a molding resin to form a substantially cylindrical shape. Therefore, there is a problem that the magnetic pole core itself is likely to be deformed into an irregular shape by the acting force when winding the magnetic pole portion.

When the magnetic pole core is deformed, the inner peripheral surface of the magnetic pole core is corrected after the completion of the winding. However, at this time, an excessive force is easily applied to the coil, and the insulation performance of the coil is apt to deteriorate. . Further, since it is difficult to perform sufficient correction in combination with the fact that an excessive force cannot be applied to the coil, the magnetic pole core has to be inserted into the outer race core in a deformed state in some cases.

In such a case, the fitting portion between the teeth of the magnetic pole core and the concave portion of the outer race core is plastically deformed, and the entire stator core is also deformed into an irregular shape. If the entire stator core is deformed, the air gap between the inner peripheral surface of the magnetic pole core and the outer peripheral surface of the rotor core will be eccentric or uneven, resulting in magnetic imbalance. Noise and vibration are likely to occur. Moreover, the plastic deformation of the fitting portion causes a variation in the fitting strength, which causes deterioration of the characteristics of the motor and generation of abnormal noise.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to suppress deformation of a magnetic pole core when winding is performed, to improve the accuracy of the entire stator core, and to fit the outer core with the outer core. It is an object of the present invention to reduce the variation in the strength of the part.

[0009]

According to a first aspect of the present invention, there is provided an electric motor in which a large-diameter portion and a small-diameter portion having different inner diameters with steps are provided on an inner peripheral surface of a magnetic pole core. In the completed state, a projection having an outer diameter that can be fitted into the small-diameter portion of the magnetic pole core is provided at a portion facing the large-diameter portion of the magnetic pole core.

A motor according to a second aspect of the present invention has an outer diameter that can be fitted into the hollow portion at one end portion in the axial direction of the rotor core and which is axially outside the hollow portion of the magnetic pole core in a completed state. A projection is provided.

A motor according to a third aspect of the present invention is the electric motor according to the second aspect, wherein the portion is located on the axially opposite side to the protrusion of the rotor core and is located axially outside the hollow portion. In addition, a protrusion having an inner diameter into which the rotor core can be fitted is provided integrally with the magnetic pole core.

[0012]

According to the first and second aspects of the present invention, the rotor core is substantially a beam provided in the hollow portion of the pole core by fitting the protrusion of the rotor core into the pole core. The acting force at the time of applying the winding is distributed throughout the rigid body composed of the magnetic pole core and the rotor core.

According to the third aspect of the present invention, the rotor core is fitted to the magnetic pole core and the rotor core is fitted to the magnetic pole core side protrusion, so that the rotor core is substantially formed. Since the beams are provided at both ends in the axial direction of the hollow portion of the magnetic pole core, the acting force at the time of winding is distributed over the entire rigid body including the magnetic pole core and the rotor core.

[0014]

[Embodiment 1] Hereinafter, an embodiment of the first invention will be described in detail with reference to FIGS. FIG. 1 is an enlarged sectional view showing a main part of the electric motor according to the first invention. FIG. 1 shows a state in which a magnetic pole core is inserted into an outer race core and then released. FIG. 2 is a sectional view showing a state at the time of winding. FIG. 3 is a perspective view showing an assembling sequence of the electric motor according to the first invention.

In these figures, 1 is a stator core,
2 is a rotor. The stator core 1 includes a magnetic pole core 3
And a resin molded part 4 provided integrally with the magnetic pole core 3.
And an outer ring core 5 fitted to the outer peripheral portion of the magnetic pole core 3 after winding the magnetic pole core 3. As shown in FIG. 3, the magnetic pole core 3 has a plurality of teeth 6 on which windings are provided radially arranged in parallel, and a hollow portion 7 into which the rotor 2 described later is inserted is formed at the axial center portion. And
The resin molding portion 4 is provided on the surface of the tooth 6 and the hollow portion 7.
Is provided so as to cover the opening at one axial end. The resin molded portion 4 closes one end of the hollow portion 7 except for opening in a shaft hole 4a through which an output shaft of the rotor 2 described later penetrates. Reference numeral 8 denotes a coil formed by winding the magnetic pole core 3.

The outer race core 5 is formed in an annular shape as shown in FIG. 3, and is configured so that the magnetic pole core 3 can be fitted to an inner peripheral portion.

The rotor 2 includes an output shaft 9 and a rotor core 10 fixed to the output shaft 9. The rotor core 10 is provided with end rings 11 and 12 at axial ends. This rotor core 10
Of the rotor core 10 in the completed state where the rotor core 10 is inserted into the hollow part 7 of the magnetic pole core 3 (FIG. 1 shows this completed state). The dimensions are set so that the determined air gap G is formed.

Here, the structure of the inner peripheral surface of the magnetic pole core 3 and the outer peripheral surface of the rotor core 10 will be described. Magnetic pole core 3
A large-diameter portion 7a and a small-diameter portion 7b having different inner diameters with steps are provided on the inner peripheral surface of the hollow portion 7 in FIG. On the other hand, the outer peripheral surface of the rotor core 10 has a large-diameter portion 10a facing the large-diameter portion 7a and having an outer diameter capable of being fitted into the small-diameter portion 7b in a completed state shown in FIG. 7
b is provided with a small-diameter portion 10b opposite to the small-diameter portion b. The step has a size corresponding to the air gap G. That is, the diameter of the large-diameter portion 7a of the magnetic pole core 3 is a value obtained by adding the air gap G for two locations to the diameter of the small-diameter portion 7a, and the diameter of the large-diameter portion 10a of the rotor core 10 is equal to the diameter of the small-diameter portion 10b. It is a numerical value obtained by adding the air gap G for two places to the diameter. Also, a part of the end ring 11 provided on the rotor core 10 is formed to have the same diameter as the large diameter portion 10a. The large diameter portion of the end ring 11 is indicated by reference numeral 11a in the figure.

In the present embodiment, the large-diameter portion 7a of the magnetic pole core 3 has a narrower forming range than the small-diameter portion 7b, and the large-diameter portion 7a is formed at the opening of the hollow portion 7 and the resin molding portion 4a. It is the opposite side to the one covered by. The opening of the hollow portion 7 where the large-diameter portion 7a is formed is covered with a resin cap 13 fixed to the magnetic pole core 3. The resin cap 13 closes one end of the hollow portion 7 except for opening at a shaft hole 13a through which the output shaft 8 of the rotor 2 passes.

In FIG. 3, reference numerals 14 and 15 denote a frame and a bracket which are the exterior of the electric motor according to the present invention. Each of the frame 14 and the bracket 15 is formed in a cylindrical shape having a bottom, and has a structure in which the stator core 1 is fixedly supported therein and the rotor 2 is rotatably supported via a bearing 16. . In addition, the output shaft 9 of the rotor 2 penetrates the frame 14 located on the lower side in FIG.

Next, a procedure for assembling the motor configured as described above will be described. First, the rotor 2 is inserted from the opening side of the hollow portion 7 into the magnetic pole core 3 in which the resin molding portion 4 is integrally provided, and the resin cap 13 is attached to the opening portion. Then, the rotor core 10 is pushed forward in the insertion direction from the position in the completed state. The state at this time is shown in FIG.
The pressing direction of the rotor 2 is indicated by an arrow A in FIG.

By doing so, the small diameter portion 7 of the magnetic pole core 3
The large-diameter portion 10a of the rotor core 10 and the large-diameter portion 11a of the end ring 11 are fitted into b. That is,
Large diameter portion 10a of rotor core 10 and end ring 11
The large-diameter portion 11a is a projection according to the present invention. Next, in this state, a winding is applied to the magnetic pole core 3 to form the coil 8. That is, at the time of winding, the rotor core 10 is fitted into the hollow portion 7 of the magnetic pole core 3, and the rotor core 10 substantially becomes a beam provided in the hollow portion 7. Therefore, the rotor core 10 can receive the acting force when applying the winding, and the acting force is distributed throughout the rigid body including the magnetic pole core 3 and the rotor core 10. That is, winding can be performed in a state where the magnetic pole core 3 is hardly deformed.

After the winding is performed as described above, the magnetic pole core 3 is pressed into the outer race core 5 and fitted. At this time, the same press-fit as when the magnetic pole core 3 in the state before the winding is fitted is possible because the magnetic pole core 3 is less deformed at the time of winding. Thereafter, the rotor 2 is moved with respect to the magnetic pole core 3 in the direction opposite to the arrow A shown in FIG.
The state of engagement between the magnetic pole 0 and the magnetic pole core 3 is released. At this time, since the outer peripheral side of the magnetic pole core 3 is fitted to the outer race core 4, the magnetic pole core 3 is not deformed even if the fitting state with the rotor core 10 is released.

Then, an assembly including the magnetic pole core 3, the rotor 2, the outer race core 4, and the like is accommodated in the frame 14 and the bracket 15, thereby completing the electric motor. At this time,
The rotor 2 is positioned so that an air gap G is formed between the rotor core 10 and the magnetic pole core 3.

Therefore, the large diameter portion 10 of the rotor core 10
a, by fitting the large diameter portion 11a (projection) of the end ring 11 to the small diameter portion 7b of the magnetic pole core 3, the rotor core 10 substantially becomes a beam provided in the hollow portion 7 of the magnetic pole core 3. Therefore, the acting force at the time of applying the winding is distributed to the entire rigid body including the magnetic pole core 3 and the rotor core 10. Therefore, the magnetic pole core 3 is hardly deformed when the winding is applied.

Embodiment 2 FIG. Next, an electric motor according to the second invention will be described with reference to FIGS. FIG. 4 is an enlarged cross-sectional view showing a main part of the electric motor according to the second invention. FIG. 4 shows a state where the magnetic pole core is inserted into the outer race core and then released. FIG. 5 is a cross-sectional view showing a state at the time of winding.
In these drawings, the same or equivalent members as those described in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description is omitted.

The motor according to the second aspect of the invention has the same configuration as the motor of the first aspect of the invention except that the structure for fitting the magnetic pole core 3 and the rotor 2 is different. In the magnetic pole core 3 used in the electric motor according to the second invention, no step is provided on the inner peripheral surface of the hollow portion 7, and the hollow portion 7 has the same diameter over the entire area. On the other hand, the rotor 2 is formed such that the end ring 11 located on the same side as the resin cap 13 can be fitted into the hollow portion 7.

That is, the end ring 11 provided at one end in the axial direction of the rotor core 10 is formed with a ridge 21 having an outer diameter capable of being fitted into the hollow portion 7. The projection 21 constitutes a projection according to the present invention. The protruding ridge 21 is formed at a position axially outside the hollow portion 7 in the completed state shown in FIG.

When winding is performed in the electric motor configured as described above, the rotor 2 is pushed in the direction of arrow A as shown in FIG. In this case, since the rotor core 10 is substantially a beam provided in the hollow portion 7 of the magnetic pole core 3, the acting force at the time of winding is a rigid body composed of the magnetic pole core 3 and the rotor core 10. Are distributed throughout. For this reason, the magnetic pole core 3
Is difficult to deform.

The motor of this embodiment is assembled in the same manner as the motor shown in the first embodiment.
Here, the description of the assembly procedure is omitted.

Embodiment 3 FIG. FIG. 6 shows the electric motor according to the third invention.
This will be described with reference to FIG. FIG. 6 is an enlarged sectional view showing a main part of the electric motor according to the third invention. FIG. 6 shows a state in which the magnetic pole core is inserted into the outer race core and then released.
FIG. 7 is a sectional view showing a state at the time of winding. In these drawings, the same or equivalent members as those described in FIGS. 1 to 5 are denoted by the same reference numerals, and detailed description is omitted.

A motor according to a third aspect of the present invention is the motor of the second aspect of the present invention, wherein the number of fitting portions between the magnetic pole core and the rotor is increased. That is, as shown in FIGS. 6 and 7, the end ring 1
1 and the end ring 1
A fitting protrusion 22 is provided on the resin molded portion 4 located on the opposite side of the resin molded portion 1 in the axial direction.

The fitting protrusion 22 is formed so that the inner peripheral wall of the bottomed cylindrical portion closing the opening of the hollow portion 7 in the resin molded portion 4 bulges radially inward. The inner diameter of the fitting projection 22 is set to a size in which the rotor core 10 can be fitted. That is, in this embodiment,
An example is shown in which a protrusion provided integrally with the magnetic pole core 3 is formed in the resin molding 4.

When winding is performed in the electric motor constructed as described above, the rotor 2 is pushed in the direction of arrow A, as shown in FIG. Is fitted to the fitting projection 22 of the resin molding 4. In this case, since the rotor core 10 is substantially a beam provided at both ends in the axial direction of the hollow portion 7 of the magnetic pole core 3, the acting force at the time of winding is limited to the magnetic pole core 3 and the rotor core. And 10 are distributed throughout the rigid body. Therefore, the magnetic pole core 3 is hardly deformed when the winding is applied.

The motor of this embodiment is assembled in the same manner as the motor shown in the first embodiment.
Here, the description of the assembly procedure is omitted.

Although FIGS. 6 and 7 show an example in which the protrusion integrally formed with the magnetic pole core 3 is formed in the resin molded portion 4, any structure that performs the same function as the fitting protrusion 22 may be used. For example, it may be formed at the axial end of the magnetic pole core 3.

[0037]

As described above, the electric motor according to the first aspect of the present invention is provided with a large diameter portion and a small diameter portion having different inner diameters with a step on the inner peripheral surface of the magnetic pole core. In the completed state, a projection having an outer diameter capable of being fitted into the smaller diameter portion of the magnetic pole core is provided at a portion facing the larger diameter portion of the magnetic pole core. The one end in the axial direction of the core, which in the completed state is axially outside the hollow portion of the magnetic pole core, is provided with a projection having an outer diameter that can be fitted into the hollow portion. In the electric motor according to the second aspect of the present invention, the rotor core can be fitted into a portion that is on the opposite side in the axial direction to the protrusion of the rotor core and that is axially outside the hollow portion. Because the protrusion with a large inner diameter is provided integrally with the magnetic pole core, By fitting the core,
The rotor core is substantially a beam provided in the hollow portion of the pole core.

Accordingly, the acting force when applying the winding is distributed over the entire rigid body composed of the magnetic pole core and the rotor core, so that the magnetic pole core 3 is hardly deformed when applying the winding. For this reason, when the magnetic pole core is press-fitted into the outer race core after winding, plastic deformation of the fitting portion can be suppressed, and the overall accuracy of the stator core can be improved. Moreover,
Variations in fitting strength can also be reduced. That is, according to the present invention, it is possible to prevent deterioration of characteristics during rotation and to prevent noise and vibration from occurring.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view showing a main part of an electric motor according to a first invention, showing a state where a magnetic pole core is inserted into an outer race core and then released.

FIG. 2 is an enlarged cross-sectional view showing a main part of the electric motor according to the first invention, showing the state at the time of winding.

FIG. 3 is a perspective view showing an assembling sequence of the electric motor according to the first invention.

FIG. 4 is an enlarged cross-sectional view showing a main part of the electric motor according to the second invention, and shows a state in which the magnetic pole core is inserted into the outer race core and then released.

FIG. 5 is an enlarged sectional view showing a main part of the electric motor according to the second invention, showing the state at the time of winding.

FIG. 6 is an enlarged cross-sectional view showing a main part of the electric motor according to the third invention, and shows a state where the magnetic pole core is inserted into the outer race core and then released.

FIG. 7 is an enlarged sectional view showing a main part of the electric motor according to the third invention, and shows a state at the time of winding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator core 2 Rotor 3 Magnetic pole core 4 Resin molding part 7 Hollow part 7a Large diameter part 7b Small diameter part 8 Coil 10 Rotor core 10a Large diameter part 10b Small diameter part 11 End ring 11a Large diameter part 21 Ridge 22 Fitting protrusion Department

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yukinori Takekoshi 1-3-3 Komabacho, Nakatsugawa City, Gifu Prefecture Mitsubishi Electric Corporation Nakatsugawa Works (56) References JP-A-3-150034 (JP, A) 63-167378 (JP, U) JP-A-2-68645 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02K 1/06 H02K 1/12-1/18 H02K 15 / 02

Claims (3)

(57) [Claims] 1. A stator core having a hollow portion in which a rotor core of a rotor is housed and around which a coil is wound, and a stator core divided into an outer race core into which the magnetic pole core is fitted. In the electric motor, a large-diameter portion and a small-diameter portion having different inner diameters with steps are provided on the inner peripheral surface of the magnetic pole core, and the outer peripheral surface of the rotor core faces the large-diameter portion of the magnetic pole core in a completed state. A motor having an outer diameter that can be fitted into the small-diameter portion of the magnetic pole core. 2. A stator core having a hollow portion in which a rotor core of a rotor is housed and around which a coil is wound, and a stator core divided into an outer ring core into which the magnetic pole core is fitted. In the electric motor, a protruding portion having an outer diameter capable of being fitted into the hollow portion is provided at a portion at one end in the axial direction of the rotor core, which is axially outside the hollow portion in a completed state in a completed state. And electric motor. 3. The electric motor according to claim 2, wherein the rotor core can be fitted into a portion that is axially opposite to the protrusion of the rotor core and that is axially outside the hollow portion. An electric motor characterized in that a projection having a large inner diameter is provided integrally with a magnetic pole core.