JP2003289655A - Cage type rotor - Google Patents

Abstract

(57) [Problem] To provide a cage rotor capable of improving material yield and reducing cost burden. SOLUTION: A ring-shaped end ring 4, 5 provided with a plurality of conductor bars 3 mounted in slots 9 of a rotor core 2 and a plurality of accommodation holes 6 accommodating ends of the conductor bars 3 at intervals.
Is a squirrel-cage rotor 1 of an induction motor to which the above-mentioned is joined. The end rings 4 and 5 are formed by bending a strip-shaped member in the width direction to have a substantially annular shape, and after joining one end and the other end thereof,
Housing hole 6 for housing conductor bar 3 by integral punching
Is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squirrel cage rotor in which a conductor bar mounted in a slot of a rotor iron core and an annular end ring are joined together.

[0002]

2. Description of the Related Art As a conventional method for manufacturing a squirrel-cage rotor, Japanese Patent Laid-Open Nos. 51-60906 and 54-14 are available.
As disclosed in Japanese Patent No. 8213 and Japanese Patent Laid-Open No. 8-294256, manufacturing methods by die casting or centrifugal casting are known. Further, Japanese Utility Model Laid-Open No. 58-11949, Japanese Patent Laid-Open No. 54-142511, Japanese Patent Laid-Open No. 7-288.
As disclosed in Japanese Patent No. 959, there is also a method of manufacturing by assembling the conductor bar and the end ring by welding or brazing.

Further, Japanese Patent Laid-Open No. 6-153469 discloses a manufacturing method in which electrical contact is made by heat generated by sliding friction between the end surface of the conductor bar and the contact surface of the end ring. A manufacturing method is disclosed in which a pressure is applied to the end surface of the conductor bar and the end ring is caulked.

[0004]

However, when a squirrel cage rotor is manufactured by die casting or centrifugal casting, it is difficult to avoid entrapment of air during injection and generation of casting defects due to internal gas. Therefore, the material yield is low and the strength of the electric motor is reduced. In this respect, the assembly type cage rotor in which the end ring and the conductor are joined by brazing, welding, sliding friction of the contact surface and caulking is superior.

However, in the above-mentioned assembly type squirrel-cage rotor, the end ring 30 is, as shown in FIG.
Since the substantially rectangular plate 31 is punched into an annular shape, the remaining portion of the plate 31 (hatched portion in FIG. 10) is wasted, resulting in a poor material yield and a large cost burden.

As a material for forming the conductor, it is preferable to use copper (1.7 μΩcm) having a low specific resistance value, but the above-mentioned assembly type squirrel-cage type rotor has a large cost burden. . For this reason, aluminum may be used, which has a lower cost burden than copper, but in the case of aluminum, the specific resistance value of the material is 1.6 times that of copper (2.7 μΩc
Therefore, there is a problem that the resistance when the secondary current is induced is large and the loss of the rotor is large.

The present invention has been made in view of such circumstances, and an object thereof is to provide a cage rotor capable of improving the material yield and reducing the cost burden.

[0008]

According to a first aspect of the present invention, a rotor core (for example, a rotor core 2 in an embodiment described later) is mounted in a slot (for example, a slot 9 in an embodiment described later). An annular end provided with a plurality of conductor bars (for example, the conductor bar 3 in the embodiment described later) and a plurality of housing holes for housing the ends of the conductor bar (for example, the housing hole 6 in the embodiment described later). In a squirrel-cage rotor (for example, a squirrel-cage rotor 1 in the embodiments described later) of an induction motor in which rings (for example, end rings 4, 5 in the embodiments described later) are joined, the end rings are A ring base material formed by bending a strip-shaped member (for example, the strip-shaped member 10 in the embodiment described later) in the width direction to have a substantially annular shape (for example, an actual substrate described later). Ring in the form of the substrate 1
2) A squirrel-cage rotor characterized in that one end and the other end of 2) are joined together.

According to the present invention, since the end ring is formed by using the strip-shaped member, the material yield is improved as compared with the case where punching is performed, and the cost burden can be reduced accordingly. As a result, even if copper is used as the material of the conductor, an increase in cost can be suppressed as compared with the conventional case, and the performance can be improved accordingly.

According to the second aspect of the present invention, the conductor bar mounted in the slot of the rotor core and the accommodation hole for accommodating the end portion of the conductor bar (for example, the accommodation hole 6 in the embodiment described later) are spaced apart from each other. In a squirrel-cage rotor of an induction motor, which is joined to a plurality of annular end rings opened and provided, the end ring is a ring base formed in a substantially annular shape by bending a strip-shaped member in the width direction. The cage rotor is characterized in that the housing hole is formed by punching after joining one end and the other end of the material.

According to the present invention, since the accommodation hole is formed by punching after joining one end and the other end of the ring base material, before joining the one end and the other end of the ring base material by welding or fusing. Unlike the case where the accommodation hole 6 is punched out, the displacement of the accommodation hole can be prevented.

The invention described in claim 3 is the invention described in claim 1 or 2, wherein the end ring and the conductor bar have a convex portion (for example, a convex portion in an embodiment to be described later) at a tip portion. A cage characterized in that the boundary portion between the end portion of the conductor bar and the accommodation hole of the end ring is joined by friction stir welding by a rotary tool (for example, the rotary tool 7 in the embodiment described later) provided with the portion 8). It is a mold rotor.

According to the present invention, the end ring and the conductor bar accommodated in the accommodation hole thereof are agitated by the convex portion of the rotary tool, and the end ring and the conductor bar can be integrated in a fused state. As a result, it is possible to secure a high connection strength without causing defects or electrical defects in the joint portion, and it is possible to suppress material costs and enhance mass productivity.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a squirrel cage rotor according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a squirrel cage rotor 1 according to an embodiment of the present invention. As shown in the figure, the squirrel-cage rotor 1 includes a rotor body 11, a rotor core 2 provided on the outer peripheral side thereof, a conductor bar 3 mounted on the rotor core 2, and an end portion of the conductor bar 3. It is provided with annular end rings 4 and 5 that can be accommodated. By assembling these, the cage rotor 1 shown in FIG. 2 is formed.

FIG. 6 is a front view of the squirrel cage rotor shown in FIG. FIG. 7 is a sectional view taken along the line AA of FIG. As shown in these drawings, the rotor core 2 is formed by laminating a plurality of plates 15 (see FIG. 7) made of, for example, steel plates, and is formed with a slot 9 which is penetrated by the conductor bar 3. There is. The conductor bar 3 is formed in a substantially cylindrical shape that is uniform over the entire length, and is formed so as to protrude from the slot 9 longer than the axial dimension of the rotor core 2.

In the present embodiment, the conductor bar 3 is
Is formed of a copper material having a low specific resistance value, whereby the resistance of the secondary current can be reduced and the loss of the rotor can be reduced. The material of the conductor bar 3 is not limited to this, and a metal having a low melting point such as aluminum may be used.

The end rings 4 and 5 are formed in an annular shape, and a pair of them are provided on both sides of the squirrel cage rotor 1. The end ring 5 has a plurality of accommodating holes 6 into which the ends of the conductor bars 3 are fitted and which are spaced from each other. The end rings 4 and 5 are also made of a copper material like the conductor bar 3. This will be described later. The cage rotor 1 is manufactured by assembling these members. FIG. 2 is an assembly view of the squirrel-cage rotor shown in FIG.

The manufacturing process of the end rings 4 and 5 will be described with reference to FIG. First, as shown in FIG. 3A, a substantially strip-shaped (in other words, rectangular and flat plate) strip-shaped member 10 made of a copper material is formed. Next, as shown in FIG. 2B, the strip-shaped member 10 is moved in the width direction (direction of arrow C).
The ring base material 12 is curved to form an annular ring base material 12.

A winding device 16 for molding the strip-shaped member 10 into a ring base material 12 is shown in FIG. The die 17 of the winding device 16 is formed in a substantially disc shape, and rotates integrally with a rotating shaft 18 provided at the axis thereof. The mold 17
A guide path 19 for guiding the strip-shaped member 10 is formed on the peripheral edge side thereof.

The leading end of the strip member 10 is connected to the guide path 19
The mold 17 is rotated while being inserted into the. As a result, tension is applied to the side 10a on the inner peripheral side of the strip-shaped member 10, and the strip-shaped member 10 is curved in a substantially annular shape along the inner peripheral side of the guide path 19. The winding device 16 is suitable for bending the strip member 10 having a relatively low rigidity.

Another example of the winding device is shown in FIG. As shown in FIG.
Are provided so as to circumscribe the die 17, and both are connected by a link 26. This allows the mold 25
Rotates following the rotation of the mold 17, and the strip-shaped member 1
The tension can be applied to 0. In this case, tension is applied to the outer peripheral side 10 b of the strip-shaped member 10, and the strip-shaped member 10 is curved in a substantially annular shape along the outer peripheral side of the guide path 19. The winding device 24 is suitable for bending the strip member 10 having a relatively high rigidity.

Then, as shown in FIG. 3C, the ring base material 12 formed in an annular shape as described above is sandwiched by a press member (not shown), and the unevenness 13 ( (See FIG. 3B), and flattening is performed. Then, one end 14a and the other end 1 of the ring base 12
4b are joined by welding, fusing, or the like to be integrated, and then the receiving holes 6 are punched at a plurality of positions at predetermined intervals in the circumferential direction at the same time or in a plurality of times, so that the end rings 4 and 5 are formed. Form.

As described above, since the end rings 4 and 5 are formed by using the strip-shaped member 10, the material yield is improved as compared with the case where punching is performed, and the cost burden can be reduced accordingly. As a result, even if copper is used as the material of the conductors such as the end rings 4 and 5 and the conductor bar 3 as described above, the increase in cost can be suppressed as compared with the conventional case, and accordingly, the cage rotor 1 can be manufactured. The performance can be improved. Further, if the housing hole 6 is punched out before the one end 14a and the other end 14b of the ring base material 12 are joined by welding, fusing, or the like, the housing hole 6 may be displaced, but in the present embodiment. In the form, one end 14a
It is possible to prevent displacement of the accommodation hole 6 by punching the accommodation hole 6 after joining the other end 14b with the other end 14b.

End rings 4, 5 formed as described above
The process for joining the conductor bar 3 to the conductor bar 3 will be described. First,
Each of the conductor bars 3 is connected to the slot 9 of the rotor core 2.
Then, the both ends 3a and 3b of the conductor bar 3 are fitted into the accommodation holes 6 of the corresponding end rings 4 and 5, respectively. In this state, the boundary portion between the accommodation holes 6 of the end rings 4 and 5 and the end portion of the conductor bar 3 is joined by friction stir welding using a rotary tool 9 having a projection 8 described later.

FIG. 8 is an explanatory view showing the welding process of the boundary portion between the accommodation holes 6 of the end rings 4 and 5 and the end portion of the conductor bar 3 in the squirrel-cage rotor 1 of FIG. FIG. 9 is a cross-sectional view showing a welded portion of the squirrel cage rotor of FIG. When performing friction stir welding, the conductor bar 3 is fixedly set in a state of penetrating the end rings 4, 5 as shown in FIG. 4, and the convex portion 8 of the rotary tool 7 shown in FIG. The rotary tool 7 is rotated at a high speed by pressing it against the surface, specifically, the accommodation holes 6 of the end rings 4 and 5, and the convex portion 8 of the rotary tool 7 is pushed into the end rings 4 and 5.

In this state, when the rotary tool 7 is rotated at a high speed as shown by the arrow D and is moved from the receiving hole 6 of the end rings 4 and 5 along the other receiving holes once or plural times, The end rings 4, 5 and the conductor bar 3 are agitated and fused in the entire area of the respective accommodation holes 6 of the rings 4, 5 (see the fusion portion 23 in FIG. 9), and the end rings 4, 5
And the end of the conductor bar 3 are joined. As a result, it is possible to secure high connection strength and prevent material cost without causing defects in the joint portion or poor electrical joint.
In addition, in the embodiment, the rotary tool 7 is circularly moved along the accommodation holes 6 of the end rings 4 and 5, but the end rings 4 and 5 may be circularly moved with respect to the rotary tool 7.

[0027]

As described above, according to the invention described in claim 1, the material yield of the end ring is improved, and the cost burden can be reduced accordingly. As a result, even if copper is used as the material of the conductor, an increase in cost can be suppressed as compared with the conventional case, and the performance can be improved accordingly. According to the invention described in claim 2, it is possible to prevent the displacement of the accommodation hole of the end ring.

According to the invention described in claim 3, it is possible to secure a high connection strength without causing a defect or an electrical defect in the joint portion, and it is possible to suppress the material cost and enhance the mass productivity.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a squirrel-cage rotor according to an embodiment of the present invention.

FIG. 2 is an assembly view of the squirrel-cage rotor of FIG.

FIG. 3 is a manufacturing process diagram of the end ring shown in FIG. 1.

FIG. 4 is a schematic explanatory view of a winding die used in the manufacturing process of FIG.

FIG. 5 is a schematic explanatory view of a winding die used in the manufacturing process of FIG.

6 is a front view of the squirrel-cage rotor of FIG. 2. FIG.

7 is a sectional view taken along the line AA of FIG.

FIG. 8 is an explanatory diagram showing a welding process of the squirrel-cage rotor shown in FIG. 2;

9 is a cross-sectional view showing a welded portion of the cage rotor of FIG.

FIG. 10 is an explanatory diagram showing a conventional problem.

[Explanation of symbols]

1 cage rotor 2 rotor core 3 conductor bar 4 End ring 5 End ring 6 accommodation holes 7 rotary tools 8 convex

Continued front page    (72) Inventor Mitsuyoshi Takao             1-4-1 Chuo Stock Market, Wako City, Saitama Prefecture             Inside Honda Research Laboratory (72) Inventor Yasuhiro Endo             1-4-1 Chuo Stock Market, Wako City, Saitama Prefecture             Inside Honda Research Laboratory F term (reference) 5H013 LL00 MM00 MM07 NN05 PP01                       PP03

Claims (3)

[Claims] 1. A squirrel-cage rotor for an induction motor in which a conductor bar mounted in a slot of a rotor core and an annular end ring having a plurality of housing holes for housing the ends of the conductor bar are joined. In the basket type rotor, the end ring is formed by joining one end and the other end of a ring base formed in a substantially annular shape by bending a strip-shaped member in the width direction. 2. An induction motor in which a conductor bar mounted in a slot of a rotor core and an annular end ring having a plurality of accommodation holes for accommodating the ends of the conductor bar are provided at intervals. In the squirrel-cage rotor, the end ring is formed by bending the strip-shaped member in the width direction and joining one end and the other end of a ring base material formed in a substantially annular shape, and then punching out the accommodation hole. A squirrel-cage rotor characterized in that 3. The end ring and the conductor bar are joined together by friction stir welding at the boundary between the end of the conductor bar and the receiving hole of the end ring by a rotary tool having a convex portion at the tip. The cage rotor according to claim 1 or 2.