JPS5854844A - Squirrel cage rotor - Google Patents

Abstract

PURPOSE:To form a squirrel cage rotor with excellent characteristics and for which a small number of manufacturing processes are required by providing slots on both sides with no skew and giving constitution in which the mutual slot distance changes its position in the central part. CONSTITUTION:Conductor grooves that are arranged in the same way as slots 2 and have a specified angle theta are machined, and the inner face of a conductor groove 9 is provided with an intermediate short circuit body 8 to which a heat resistant insulation paint is applied. When this intermediate short-circuit body 8 is placed between the iron core blocks 6 and 7 to form a laminated iron core 11, the slot 2 of the iron core block 6 is aligned with the slot 2 of the iron core block 7, and the conductor groove 9 forms the slot pitch between the iron core blocks 6 and 7 in one slot pitch skew. A squirrel cage coil 5 that consists of slots 2, conductor grooves 9 and conductor 3a in the slot conductor 3 and conductor groove 9 and end ring 4 is formed by aluminum diecasting.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a squirrel cage rotor for an induction motor, and more particularly to improving the characteristics of an aluminum cast squirrel cage rotor.

Conventionally, the squirrel cage rotor of an induction motor is made by punching out a plurality of equally spaced slots 2 on the outer periphery of a thin iron plate 1 as shown in FIG. A squirrel-cage winding consisting of the C conductor 3 and the end rings 4 on both sides is cast in aluminum.In addition, the conductor 3 usually has an angle θ with respect to the axial direction, that is, a skew of all stages. be.

The purpose of providing this skew is to prevent abnormal torque, vibration, and noise from occurring when the induction motor is started. However, although this skew gold film improves the above characteristics, it will cause cross current loss between the conductors 3 in the slot 2, which will reduce the efficiency of the motor and also cause this cross current loss. This loss also causes a rise in temperature.To avoid this, conventionally, after laminating thin iron plates 1, the inner surfaces of the many slots 2 were insulated with phenol, etc. to reduce cross flow loss. In addition to this work process being required, there were other drawbacks such as the need for special heat-resistant paint on the phenol to create an insulating coating that could withstand the temperature and pressure of aluminum die-casting.

The purpose of the present invention is to create a squirrel cage rotor with no skew in its slots, so that it can obtain good starting characteristics similar to those with skew (the slots on the two sides are free of skew, and the slots between the two slots are in the center). Since the position of the parts is changed, there is no skew (Secondly, the purpose is to provide a squirrel cage positive trochanter with good characteristics, which does not require slot insulation treatment and has low cross current loss. The following is the configuration of the present invention. The explanation will be given with reference to the drawings of all the embodiments.However, the same parts as the above-mentioned conventional ones will be given the same reference numerals and detailed explanations will be omitted. ≦2. The thin iron plate 1 of the rotor is formed by punching out a plurality of slots 2 radially on the outer circumference C2 of the thin iron plate 1, as in the conventional case.

When laminating a plurality of thin iron plates 1 to form a laminated iron core, the third
As shown in the figure, two blocks 6 and 7 spaced apart at the center of the total length of the axial stack are laminated. An intermediate short-circuit member 8'' is provided so that the conductor 3a that is immediately cast in the axial direction has a predetermined non-cue.

For example, this intermediate short-circuit body 8 is formed on the outer periphery of a material made of aluminum having a predetermined thickness, and is equidistant with a plurality of slots 2 punched out on the outer periphery of the thin iron plate l of the squirrel-cage positive trochanter at a predetermined angle θ.
A plurality of fully-functioning conductor grooves 9 are processed and provided, and conductor #I
The inner surface C2 of I9 is coated with heat-resistant insulating paint 10. When this intermediate short-circuit body 8 is sandwiched between the core blocks 6 and 7 to form the laminated core 11, the slots 2 of the core blocks 6 and 7 on both sides are aligned in the same axial direction as shown in FIG. The skewed conductor grooves 9 of the intermediate short-circuit body 8 are formed into a skewed slot pitch pattern between the core blocks 6 and 7. However, slot 2
, the conductor groove 9 and its both end faces are formed by die-casting a squirrel cage winding 5'f consisting of the conductor 3 in the slot, the conductor 3a in the conductor groove 9, and the end ring 4 by die casting.

According to the above configuration C-, the slots 2 of the inner core blocks 6 and 7 have an apparent skew of angle θ when viewed from both directions of the shaft ends, as shown in FIG. It is possible to prevent the generation of abnormal torque, vibration, and noise at the time of starting, and also to prevent losses due to cross flow mini during operation. Furthermore, since the slots 2 are not skewed, there is no need to perform face treatment on the inner surfaces of the slots 2 in order to prevent crossflow losses, unlike in conventional skewed rotors.

Oka, the slot shape was explained above as a semi-closed slot, but
Similar effects can be obtained with a fully closed slot or a double squirrel cage slot, and a three-phase induction motor or a single-phase induction motor 52 can also be applied, and the number of iron core blocks may be two or more.

In addition, the material of the intermediate short-circuit body 8 is set to a preheating temperature of the iron core before aluminum casting, and a temperature of 150 to 250, which is maintained for a relatively long time after solidification of the molten aluminum of the cast conductor 3 & 2. ℃, and has a melting point of, for example, 250° C. to 450° C., so that the cast conductor 3a can be eluted and removed at a relatively low temperature after solidification. The cage-shaped winding 5'tl-aluminum consisting of the conductor 3 and the end ring 4 in the slot 2 is cast using gold, a zinc-based alloy material for die casting, and after solidification, the intermediate short-circuit body 8 is cast.
The present invention is not limited to the above-mentioned examples and is not limited to the examples shown above, and can be carried out in various ways without changing the gist thereof. Of course.

As described above, according to the present invention C2, the slot is not skewed but isometrically ζ-niskewed, and both the starting characteristics and the operating characteristics are good even without face treatment on the slot inner surface. Therefore, it is possible to obtain a squirrel-cage positive trochanter with good characteristics and a small number of manufacturing steps.

[Brief explanation of the drawing]

1N is a plan view of a thin iron plate for a conventional squirrel cage positive trochanter;
The figure is a front view of a conventional squirrel cage positive trochanter manufactured by laminating thin iron plates, FIG. 3 is a front view of a squirrel cage positive trochanter according to an embodiment of the present invention, and FIG. 4 is a front view of a squirrel cage positive trochanter manufactured by laminating thin iron plates. It is a sectional view taken along line l. 1...Thin iron plate 2...Slot 3...Conductor 3a Middle skew-shaped conductor 4...End ring Dan...Squirrel cage winding 6.7...Iron core block 8...Middle Short circuit body 9...Conductor groove 10...Heat-resistant insulating paint 11...Laminated core θ...Skew angle Fig. 1 4 Fig. 2 Fig. 3 26j

Claims (1)

[Claims] Outer circumference ≦ 1 Slot part of cylindrical laminated core with multiple slots 2 - 1 conductor and both end faces 1 Ni end ring made of aluminum cast) Core block C: The slot conductors of each block are aligned in the same axial direction, and the conductors with a predetermined skew angle are all interposed between each core block. A squirrel cage rotor characterized by being combined with a conductor.