JPS59209049A - Die cast rotor - Google Patents

Abstract

PURPOSE:To obtain a die cast rotor having high reliability by providing projections on the side wall of a rotor slot. CONSTITUTION:A rotor conductor 3 is formed of die cast 5, 7 in slots 5 of a rotor core 2 supported by a rotational shaft 1. In this case, a plurality of projections 7b are formed on the side wall 7a of the slot 7. When high temperature and high pressure molten metal is filled in the slot 7 and cooled to room temperature, a gap 6 is formed between the slot 5 and the conductor 3 due to the difference of expansion coefficients of both, but the projections 7b are intruded into the side of the conductor 3. Accordingly, the movement of the conductor 3 in the slot 7 is restricted. In this manner, the bending stress due to the bending toward the outer periphery can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a die-cast rotor for an induction motor that rotates at high speed.

A conventional die-cast rotor of this type is shown in FIG.

In the figure, (1) is the rotating shaft, (2) is the rotor core supported by the rotating shaft +11, (3) is the rotor conductor formed by die-casting in the slot (5) of the rotor core (2), (4) is an end ring that is formed integrally with the rotor conductor (3) and connects the ends of one rotor conductor (3).

To manufacture the die-cast rotor configured as described above, the rotor core (2) supported in a mold (not shown) is assembled into a die-casting machine (not shown), and a high-temperature metal such as aluminum is melted (for example, aluminum). is injected at high pressure from the sprue of the mold, and after the two-rotor core (2) has cooled to room temperature, it is removed from the mold by removing the rotor conductor (3).
) and the end link (4), for example aluminum, has a larger coefficient of expansion than the steel plate that makes up the rotor core (2).

When cooled to room temperature, a gap (6) is created between the slot (5) and the rotor conductor (3) as shown in FIG.

As mentioned above, the conventional tie-cast rotor has slots (5
) and the rotor conductor (3), so if the rotor conductor (31 is shown in Figure 3) is rotated at a high speed example of 9 rotor conductors (31 is shown in Figure 3). Since both ends are fixed with end rings (4) and the beam is subjected to a bi-uniformly distributed load, the centrifugal force causes the central part to curve toward the outer circumference, as shown by the broken line A.As a result, starting and stopping the beam When used frequently in machine tools, etc., there is a drawback that fatigue failure occurs due to repeated loads due to long-term use, combined with thermal stress generated during startup.

The present invention aims to eliminate the above-mentioned drawbacks of the conventional rotor, and provides a die-cast rotor in which protrusions are provided on the side walls of the slots to prevent the rotor conductors from moving in the outer circumferential direction. It is something.

An embodiment of the present invention will be described below with reference to FIG. In the figures, the same reference numerals as in Figures 1 to 3 indicate the same straddle-corresponding parts;
7.2 is the rotor slot formed.

The high temperature melted into the slot (7) formed as in C.
An analogy for high-pressure metals is that when aluminum is injected using a die-casting machine and then cooled to room temperature, the slots (5) and rotor A gap (6) is created between the conductor (3) and the conductor (3). If a rotor configured in this manner is operated at high speed, for example, at a speed of one rotation per minute.

The conventional one has a rotor conductor (3) as shown in Figure 3.
is curved in the outer circumferential direction due to centrifugal force, but in the above embodiment in which the protrusion (7b) is formed on the side wall (7a) of the slot 7), the protrusion (7b) is curved on the side of the rotor conductor (3). Since the rotor conductor (
3) is restrained, and bending stress due to curvature in the outer circumferential direction is prevented from occurring in the two-rotor conductor (3), so fatigue failure will not occur even if frequent starting and stopping are repeated. do not have.

Alternatively, a similar effect can be obtained by using a wavy convex portion (7d).

As described above, according to the present invention, since the protrusion is provided on the side wall of the two-rotor slot, even if a gap is created between the slot male rotor conductor and the slot female rotor conductor due to shrinkage of the rotor conductor after tie casting, the single rotor conductor To provide a highly reliable tie-cast rotor that can sufficiently withstand high-speed rotation because movement within the slot is restricted and no bending stress is generated even if centrifugal force is applied to the two-rotor conductor. I can do it.

[Brief explanation of drawings]

Figures 1 to 3 show conventional examples, Figure 1 is a vertical concave view of the upper half, Figure 2 is a cross-sectional view showing the state of the void that occurs after die casting, and Figure 3 is rotation due to high speed rotation. An explanatory diagram showing the state of deformation of the child conductor, and FIG. 4 shows an embodiment of the present invention.
5 and 6 are cross-sectional views showing other embodiments of the present invention. In the figures, the same reference numerals indicate the same or equivalent parts, (
3) is the rotor conductor, and (7) is the rotor slot. (7a) is a side wall, and (7b) is a protrusion. Agent Masuo Oiwa (2 people) Figure 2, 3rd circle

Claims (1)

[Claims] A die-cast rotor characterized in that a side wall of a rotor slot is provided with a protrusion that prevents a rotor conductor from moving in an outer circumferential direction.