JPS609351A - Squirrel-cage rotor - Google Patents

Abstract

PURPOSE:To improve the efficiency by insulating a rotor core and a squirrel- cage secondary winding formed by filling melted conductor, and flowing the secondary current in the prescribed loop. CONSTITUTION:A rotor core 11 is formed by laminating many steel plates, and a plurality of slots 12 for a quirrel-cage winding are formed at the prescribed interval. An electrically insulating coating is formed on the surface of the core 11. Melted conductor such as aluminum is filled in the slots 12, and the squirrel- cage secondary winding of aluminum is integrally formed with the core 11 thus coated to form a squirrel-cage rotor. Since the core 11 and the winding are sufficiently electrically insulated therebetween, the secondary current is flowed in the prescribed route even if the contacting degree therebetween increases.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a squirrel cage rotor in which secondary conductors and end rings are formed by injection of molten conductive material.

[Technical background of the invention and its problems]

Generally, in the rotor of a small induction motor, a molten conductive material such as aluminum is injected into a slot provided in the rotor core to integrally form a secondary conductor and an end ring that commonly connects both ends of the secondary conductor. So-called die-cast rotors are widely used. In such a die-cast rotor, a cage made of a conductive material corresponding to a secondary winding is formed as shown in 2, front 7+R, and then an anti-corrosion treatment is applied to the outer circumferential surface and the casting surface of the rotor.

However, when manufactured in this manner, since both the core and the squirrel cage secondary winding are electrical conductors 4), Piv occurs during which the secondary current does not flow in a predetermined path. In other words, Fig. 116 is a diagram cut along the outer circumferential surface of a die-cast rotor at a predetermined depth from the outer circumferential surface (a portion shallower than the bottom of the slot). is a plurality of slots provided near the outer peripheral surface of this rotor core, (1j is a cage-shaped secondary winding, and a bar (1j) is formed by injecting a molten conductor into the slot α2.
3 (Z) and an end ring (13k).

Here, during operation, a secondary current should originally flow through the rotor core in the loop shown by the arrow (to). However, as mentioned above, in the case of a die-cast rotor, the squirrel-cage secondary winding is formed by directly injecting the molten conductor into the slot Oz of the conductive rotor core αD, so there is no electrical insulation between them. Arrow prisoner ω】(The quadratic positive flow flows through several loops as shown by 0. For this reason, the force (
(torque), which caused a decrease in torque and an increase in slip.

[Purpose of the invention]

The object of the present invention is to provide a rotor core and a squirrel cage secondary winding formed by injection of molten FAj1 conductor.

The object of the present invention is to provide a squirrel-cage rotor in which a secondary current is caused to flow in a predetermined loop to improve the power ratio.

[Summary of the invention]

The squirrel cage rotor according to the present invention includes a rotor core that is laminated to have a plurality of slots and has an electrically insulating coating formed on its surface, and the above-mentioned coating is formed in the slots and on both end surfaces of the rotor core. The rotor core is provided with two die-cast bars and an end ring, and the coating insulates between the rotor core and the die-cast bars and end rings, and allows the secondary current to flow in a constant loop. It is something.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.

Figure J-1 shows the rotor core (11), which is made up of a number of laminated plates. Also near its outer surface.

A plurality of slots for cage-shaped secondary winding are provided at predetermined intervals. The surface of the rotor core (11) (including the inner surface of the slot) is coated with an electrically insulating coating when the rotor core (11) is in the form shown in FIG. This coating uses aluminum as an IF conductor with an instantaneous heat resistance of several hundred C (molten), and its M tl temperature is about 680 C), or by superheated steam treatment at 5 OOC. -So-called steam treatment to form an asymmetric film of 5P F,,04, so-called black coating to form a black oxide film on the surface by heating to 4OOC or more in the atmosphere, 6- to 5P immersion in a phosphate solution Faults such as so-called parkerizing, which forms a phosphate film on B glue.
All you have to do is perform an integrated process.

A molten conductor (for example, aluminum) is injected into the slot a4 of the rotor 1a (11) which has been coated in this manner, and a cage flying secondary winding made of aluminum is made! [k] is integrally formed to produce a die-cast F-J squirrel cage rotor as shown in Figure 2.

Here, the above-mentioned injection of molten aluminum is performed as follows. That is, the rotor core a0 shown in FIG. are opposed to each other in the recessed space.

Furthermore, an upper mold having a concave space for molding the end ring (134') is attached to the other end surface of the rotor core αD, and the ends of the slots 02) that open on the other end surface are opposed to each other in the concave space. let Then, molten aluminum is injected into the recessed space from a liner for supplying molten aluminum formed in the upper mold through a narrow bin gate. The molten aluminum injected into the recess space enters each slot and passes through the slot into the four-part space of the lower mold. In this way, melt the aluminum into each slot α of the rotor core (old).
After injecting the molten aluminum into the concave spaces facing 2 and both ends thereof, the molten aluminum is cooled and solidified. Thereafter, the upper and lower molds are separated, and the solidified aluminum is cut using a bin gate to form a die-cast squirrel cage rotor as shown in Figure 2.

Here, the temperature of the molten aluminum is about 680C as mentioned above, but the coatings based on each of the above-mentioned coatings (・7-) have a temperature of W < 1. , electrical insulation is maintained between the rotor core (11) and the cage-shaped secondary winding HI3) made of aluminum die-casting. Therefore, the second order that ητ occurs when driving? The lj flow flows in a predetermined loop indicated by the arrow ω in Fig. 6, and generates sufficient torque.

7I, cage-shaped secondary 9(1) by aluminum die-casting
3) is molded in the recessed space of the upper mold; (2) Aluminum solidified in a bin gate is integrally formed as a protrusion on one end ring. This protrusion is not desirable due to the characteristics of the motor, and is removed by machining. In this case, if you add Narayamachining, the rotor core (11)
Since the adhesion between the aluminum and the machined aluminum becomes stronger, in the case where the conventional ferrule has not been applied, the secondary current flows more into the loop shown by arrow 3 (■ in Figure 3) (0), which increases the torque. However, in the present invention, since there is sufficient electrical insulation between the rotor core 01) and the squirrel cage secondary winding, even if the degree of adhesion between them becomes strong, the
The next current flows along a predetermined route indicated by an arrow (to).

Therefore, there is no reduction in torque.

〔Effect of the invention〕

As described above, according to the present invention, the electrically insulating coating provided on the rotor core provides sufficient insulation between the rotor core and the squirrel cage secondary winding heddle, and the secondary current generated during operation is directed to a predetermined route. Because of this flow, a highly efficient squirrel cage rotor is obtained that does not suffer from defects such as reduced torque or increased slippage.

[Brief explanation of drawings]

Figure 1 is a perspective view showing an example of the shape of the rotor core used in the present invention, Figure 2 is a perspective view showing an embodiment of the squirrel cage rotor according to the invention. , flow. This is a member-direct view of Figure 2 showing the oil path. (11) e-skewer rotor core, (12) shaft/slot, (+
:()...Squirrel cage rotor, (13α)...Bar, (13
,6)...end ring.

Claims (1)

[Claims] A rotor core laminated to have +11 4i number of slots and having an attractive insulating coating formed on its surface, and die-cast bars and end rings formed in the coated slots and on both end faces of the rotor core. A squirrel cage rotor characterized by being equipped with.