JPH05292714A - Induction motor - Google Patents

Abstract

PURPOSE:To improve an efficiency and to reduce a cost by shortening a length of an end of a stator coil, shortening a length per one turn of the coil, and shortening a profile length of a motor to reduce its weight. CONSTITUTION:A stator core 11 is divided into a yoke 11a and a plurality of toothed parts 11b per each phase and formed by punching. Stator coils 13U, 13V, 13W are concentrically wound at laminated toothed parts 11b. The parts 11b are fixed to the laminated yoke 11a circumferentially at an equal pitch, and the coils 13U, 13W are wired in polyphase-windings to form a stator winding 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction motor used in, for example, an electric vehicle drive motor, and more particularly to a stator core and a stator winding.

[0002]

2. Description of the Related Art FIGS. 6A and 6B are a development view of a stator core and a development view of a stator winding of a conventional induction motor.
Three-phase, four-pole, single-layer concentrated winding. Reference numeral 1 denotes a stator core, which has a yoke portion 1a, teeth 1b, and slots 1c. Reference numeral 2 denotes a stator winding, in which a stator coil 3 of each phase of U, V, and W, which is wound a plurality of times, is inserted into the slot 1c and is Y-connected.

FIG. 7 (A) is a front view of the stator winding 2 portion mounted on the stator core 1 and FIG. 7 (B) is a front view thereof.
It is shown in a sectional view taken along the line BB of (A). Stator core 1
The yoke portion 1a and the tooth portion 1b are integrally punched from an electric iron plate and laminated. The coil ends of the stator coils 3 of the respective phases overlap and overlap the adjacent phases, and the stator coil 3 has a considerably large slot pitch, and thus is elongated in the axial direction.

When three-phase AC power is supplied to the U, V, and W terminals of the stator winding 2, a rotating magnetic field of four poles is generated, passed through a rotor core (not shown), and a voltage is applied to the rotor conductor. Is induced to cause a rotor current to flow, and a torque is generated to rotate the rotor.

[0005]

The conventional induction motor as described above has a problem in that the coil end portion of the stator winding 2 is lengthened in the axial direction and the outer shape of the motor is lengthened in the axial direction. .. In addition, the total length of the wires of the stator winding 2 becomes long, the winding resistance value becomes large, the copper loss increases, the efficiency of the electric motor decreases, and the stator coil 3 is difficult to manufacture and assemble, resulting in productivity. There was a problem such as low. In addition, since the coil ends of the adjacent phases overlap, there is a problem that it is necessary to strengthen the interphase insulation between the two.

The present invention has been made in order to solve the above-mentioned problems, and shortens the length of the coil end portion of the stator coil to shorten the length per turn, and the outer shape of the electric motor. Shortening the length and making it lighter weight, improving efficiency, making it cheaper, further facilitating the production of the stator coil and improving productivity, eliminating the interphase insulation of the coil ends, eliminating the accident of interphase short circuit, The purpose is to obtain an induction motor with improved reliability.

[0007]

SUMMARY OF THE INVENTION In an induction motor according to the present invention, a stator core is separated into a yoke portion and a plurality of tooth portions for each phase, and a stator coil is concentratedly wound around each tooth portion. , Tooth parts are arranged on the yoke part at equal pitch in the circumferential direction and fixed,
Each fixed coil is connected to a multiphase winding to form a stator winding.

[0008]

In the present invention, the stator coil is wound around each separated tooth portion of each phase, and the tooth portion in this state is fixed to the yoke portion of the stator core. The property is improved. Further, the length of the coil end portion is shortened, the outer shape length of the electric motor is shortened, and further, the total length of the wire of the stator winding is shortened, and the efficiency of the electric motor is improved.

[0009]

EXAMPLES Example 1. 1A and 1B are a development view of a stator iron core and a development view of a stator winding of an induction motor according to an embodiment of the present invention, which are three-phase four-pole concentrated windings. Reference numeral 11 denotes a stator iron core, which is formed separately from a yoke portion 11a (which is shown in an expanded state in the drawing, but has a cylindrical shape as shown in FIG. 2A), and a dovetail joint portion 11d.
The tooth portion 11b is press-fitted and fixed to the yoke portion 11.
Slots 11c are formed between the tooth portions 11b. 12
Is a stator winding, and a stator coil 13 of each phase of U, V, and W, which is wound around each tooth 11b a predetermined number of times, is Y-connected.

The stator winding 12 portion mounted on the stator core 11 is shown in FIG. 2 (A) in a front view, and FIG. 2 (B) is a sectional view taken along line BB in FIG. 2 (A). Indicates. The yoke portion 11a of the stator core 11 is formed by stacking annular iron core plates punched from an electric iron plate to form a cylindrical shape. A stator coil 13 is wound around the tooth portion 11b addressed to each pair of phases. Therefore, the stator coil 13 for two phases is inserted in the slot 11c.
Is accommodated, the coil end portion is only in that phase, does not overlap with other phases in the radial direction, and the axial length is shortened. The crossovers between the stator coils 13 of each phase only overlap the coil ends. As for the stator coil 13, a plurality of coils (two in the figure) obtained by winding around the tooth portion 11b before being fixed on the yoke portion 11a are combined, and after winding, the yoke portion 1b.
It is mounted by press-fitting and fixing the tooth portion 11b to 1a.

Manufacturing of each tooth portion 11b of the stator core 11 is as follows.
Do the following: First, as shown in FIG. 3 (A), an electric iron plate is pressed as a series connection body having a total number of tooth portions 11b spaced apart from each other by a predetermined distance and a connecting crosspiece portion 11e connecting between the tooth end portions. Form by punching. This punched iron core plate is laminated to a predetermined iron core length and fixed by welding or the like. This is formed into a circular shape as shown in FIG. 3 (B), each tooth 11b is insulated from the ground, the stator coil 13 is wound, and after winding,
As shown in FIG. 2A, the dovetail joint portion 11d is press-fitted and fixed to the yoke portion 11a. As shown in FIG. 3 (A), since two sets of the serially connected body of the tooth portions 11b can be punched with their backs aligned, the material yield is good and the mass productivity is excellent.

Example 2. FIG. 4 is a sectional view showing a stator coil portion wound around a tooth portion according to Embodiment 2 of the present invention. Reference numeral 15 is a winding frame made of an insulative synthetic resin molded product, around which the stator coil 13 is wound. The winding frame 15 around which the stator coil 13 is wound is inserted and fixed in the tooth portion 11b. This ensures reliable ground insulation of the stator coil 13, improves reliability and enhances productivity.

Embodiment 3. In the above embodiment, the case of the inner rotary type induction motor having the rotor inside the stator is shown, but it is also applicable to the case of the outer rotary type induction motor in which the rotor is arranged outside the stator. .. This is shown in a front sectional view in FIG. Reference numeral 21 denotes a stator core, and a plurality of pairs (three pairs in the figure) of tooth portions 21 are press-fitted and fixed to the outer periphery of the yoke portion 21a by dovetail means 21d. A slot 21c is formed between the adjacent tooth portions 21. Stator core 21
Are fixedly supported by a fixed shaft 24. A stator coil 23 is wound around each tooth portion 21, and each phase of U, V, and W is Y-connected, for example, to form a stator winding 22 having three phases and four poles.

[0014]

As described above, according to the present invention, the length of one turn of the stator coil is shortened, the length of the coil end is shortened, and the outer length of the electric motor is reduced. Then
Lightweight and cheap. Further, the resistance value of the stator winding is reduced and the efficiency is increased. Further, the stator coil can be easily wound around the tooth portion, the productivity is improved, the overlapping portion between the adjacent phases is eliminated, and the interphase insulation is not required, and the reliability is improved.

[Brief description of drawings]

1A and 1B are a development view of a stator core and a development view of a stator winding of an induction motor according to an embodiment of the present invention.

2A is a front view in which a stator winding is mounted on the stator core of FIG. 1, and FIG. 2B is a cross-sectional view taken along line BB of FIG.

3A is a front view showing a punched state of the iron core tooth portion of FIG. 2A, and FIG. 3B is a front view of a state where the iron core tooth portions of FIG. It is a figure.

FIG. 4 is a cross-sectional view showing a second embodiment of the present invention in a state where a stator coil is wound around a winding frame and mounted on a tooth portion.

FIG. 5 is a front sectional view showing a stator of an outer rotation type induction motor according to a third embodiment of the present invention.

6A and 6B are a development view of a stator core and a development view of a stator winding of a conventional induction motor.

7A is a front view in which a stator winding is mounted on the stator core shown in FIG. 6, and FIG. 7B is a sectional view taken along line BB in FIG. 7A.

[Explanation of symbols]

 11, 21 Stator core 11a, 21a Yoke part 11b, 21b Tooth part 11e Connecting bar part 12, 22 Stator winding 13, 23 Stator coil

Claims (2)

[Claims] 1. A cylindrical yoke portion formed by stacking punched iron core plates, and laminated punched iron core plates, each of which is arranged and fixed to the yoke portion, and a plurality of tooth portions are provided for each phase. A stator core and a stator coil wound around each of the tooth portions are provided, and the stator coil is wound around each tooth portion in advance.Each tooth portion in this state is circumferentially distributed around the yoke portion. An induction motor characterized in that the stator coils are arranged and fixed at a pitch, and the stator coils are connected to a polyphase winding to form a stator winding. 2. Each tooth portion of an iron core plate punched out from an electric iron plate has a connecting crosspiece between both adjacent tooth ends to form a linear continuous body. From this state, a circular shape is formed. The induction motor according to claim 1, wherein the induction motor is molded into a sheet and fixed to a yoke portion.