JPS6130445Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a rotor for an induction motor.

The rotor of a conventional induction motor consists of laminated electromagnetic iron plates 1 each having a plurality of slots, as shown in Fig. 1.
Aluminum is cast into the slot by die casting. Then, a conductor 2 through which a rotor current flows, a short-circuit ring 3, a vane 4 for internal air circulation, and a wart 5 for attaching a rotor balance correction weight are formed. This feather 4
The motor has 12 to 24 blades, and the rotation of the rotor circulates the air inside the motor to dissipate the heat generated from the motor. The blade 4 accounts for approximately 20 to 30% of the total amount of aluminum used in the rotor.
Although the function of the blades 4 is simply to circulate internal air, using expensive aluminum for the conductive material is uneconomical and expensive in terms of saving materials. Also this feather 4
Installing a separate fan instead of the rotor also significantly increases the cost of the fan and greatly reduces the productivity of rotor assembly.

The present invention improves the above-mentioned drawbacks by laminating electromagnetic iron plates with vanes formed by pressing on both ends of the rotor core, and forming the rotor conductors and short-circuit rings by aluminum die-casting. The purpose of the present invention is to provide a rotor for an induction motor that saves materials and reduces costs.

The present invention will be explained below with reference to FIGS. 2 to 4. FIG. 2 is a front view of an end plate used in a rotor showing an embodiment of the present invention, in which an end plate 6 is made from a band-shaped electromagnetic iron plate using a press (not shown) and has the same inner and outer diameters as the electromagnetic iron plate 1 for the rotor. Punch out. Next, a plurality of holes 7 are punched out on the outer periphery of this end plate 6, and three sides of the fan-shaped annular piece are punched out on the outer periphery, and the remaining one side is bent to form a blade 8. It is arranged at right angles to the plane of the plate 6. A plurality of blade holes 8a for forming the short-circuit ring 3 are made of cast aluminum in the vicinity of the bend at the base of the blade 8.
The blade holes 8a are set so that the total area of the blade holes 8a is equal to the cross-sectional area of the short circuit ring 3. Further, the bent remaining portion 6a of the blade 8 is made narrower than the slot pitch so that the bent portion 6a does not block the slot of the rotor. For the end plate 6, a silicon steel plate with a thickness of 0.5 mm is used for a small-sized rotor, and a silicon steel plate or a common steel plate with a thickness of 0.8 mm or more is used for a medium-sized or larger rotor.

A method of forming rotor blades using end plates having such a shape will be described. Electromagnetic iron plates 1 for a rotor having a plurality of slots are laminated,
After adjusting the skew to a specified value, the end plates 6 are brought into contact with both ends of the stack and press-fitted into the core metal. The rotor core contained in the core metal is inserted into a die-casting machine (not shown), and aluminum is cast into the slot. This aluminum passes through the hole 7 of the end plate 6 and the blade hole 8a to form the short circuit ring 3 and the wart 5 for attaching the balance correction weight. At this time, the end plate 6 is fixed to the rotor by forming the short circuit ring 3, and the blades 8 are formed as rotor blades 4a as shown in FIG. Since the rotor blades 4a protrude from the end face of the short-circuit ring 3 in the same manner as before, the cooling function is exactly the same as that of the conventional aluminum blades 4, and the amount of aluminum used as a conductive material is per rotor. It can be reduced by about 20 to 30% compared to the conventional one (reduction of rotor blades 8).

Since the root of the rotor blade 4a is embedded in the shorting ring 3 while filling the blade hole 8a with aluminum, the rotor blade 4a is firmly fixed to the shorting ring 3. Therefore, the centrifugal force and circumferential force generated by the rotation of the rotor are received by the thick part of the short circuit ring 3 without being concentrated on the bent part of the rotor blade 4a, and the rotor blade 4a is Thickness is 0.5
Support strength is improved even when using relatively thin material (mm). Therefore, there is no risk of breakage or deformation of the rotor blades 4a at the bent portions during rotation of the rotor, and it is possible to obtain desired motor characteristics with good reliability.

As described above, according to the present invention, instead of the conventional aluminum blades of the rotor, end plates with blades formed by punching and bending are fixed during rotation by aluminum casting. It is possible to reduce product costs by reducing the amount of aluminum used as conductive material by about 20 to 30% without sacrificing productivity and motor properties. In addition, the rotor blades can be supported by the thick aluminum part of the short-circuit ring, which can also contribute to preventing breakage and deformation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the top of a conventional rotor, FIG. 2 is a front view of the top of an end plate showing an embodiment of the present invention, and FIG.
The figure is a perspective view showing the blade bent at the end plate, and FIG. 4 is a perspective view showing the main part of the bladed end plate of the present invention cast into the rotor. 1...Electromagnetic iron plate, 3...Short circuit ring, 4...Blade,
4a... Rotor blade, 6... End plate, 7... Hole, 8
...Blade, 8a...Blade hole.

Claims (1)

[Scope of utility model registration request] Electromagnetic iron plates having a plurality of slots are laminated to form a rotor core, and end plates having a plurality of holes perforated on the outer periphery and a plurality of blades formed by punching and bending are arranged at both ends of the rotor core. In an induction motor rotor formed by casting aluminum into the slots, the blades of the end plate are provided adjacent to the holes, and a plurality of blade holes are bored at the base of the blades, and the blades are formed by casting aluminum into the slots. A rotor for an induction motor, characterized in that a rotor blade is formed by embedding a blade hole in a short-circuit ring formed while filling the blade hole with aluminum.