JPH0747975Y2 - Induction motor rotor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rotor of an induction motor that constitutes a rotating portion of the induction motor.

2. Description of the Related Art In recent years, there has been an increasing demand for a rotor of an induction motor that has improved efficiency by reducing the magnetic flux density in the gap between the stator and the rotor.

As shown in FIGS. 3 and 4, a conventional rotor of this type of induction motor has a plurality of substantially elliptical secondary conductor grooves 102 arranged in the radial direction near the outer periphery of a circular rotor 101. Was configured.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In such a conventional induction motor rotor configuration, the interval between the secondary conductor grooves 102 arranged in parallel is narrowed, and the magnetic flux density in the portion A having the narrowest interval is increased. There was a problem of reduced efficiency.

In addition, the magnetic flux in the gap between the stator (not shown) and the rotor 101 has a problem that the opening 103 portion of the rotor groove 102 becomes weaker than the others and efficiency deteriorates.

The present invention solves the above-mentioned problems by providing an induction motor having a shape in which the spacing between the secondary conductor grooves is widened so that the magnetic flux density in the rotor does not increase and the magnetic flux density in the gap is uniform. The purpose is to provide a rotor.

In order to achieve the above-mentioned object, the rotor of the induction motor of the present invention has circular secondary conductor grooves of the rotor so that the radial distances from the center of the rotor are alternately different. The outer diameter of the rotor is arranged in a staggered pattern in the vicinity of the outer periphery and is close to the opening of the secondary conductor groove close to the outer periphery. It is made smaller than the outer diameter.

The rotor of the induction motor according to the present invention has the above-described structure.
The distance between the circular secondary conductors is wider than in the conventional example to reduce the magnetic flux density in the rotor, and the magnetic flux in the gap between the stator and the rotor is also close to the rotor groove. The gap in the portion close to the opening is larger than the gap in the portion close to the opening of the rotor groove far from the outer periphery, and the gap is made uniform, and the magnetic flux density is reduced.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. As shown in the figure, at a position near the outer circumference of the substantially circular rotor 1, the radial distance Ra from the center of the rotor 1 and
Circular secondary conductor grooves 4 and 5 having openings 2 and 3 are arranged in a staggered manner so that Rb is alternately different, and the outer diameter dimension φDa at the position of the opening 2 of the secondary conductor groove 4 near the outer circumference is It is configured to be smaller than the outer diameter dimension φDb at the position of the opening 3 of the secondary conductor groove 5 far from the outer periphery.

In the above configuration, the secondary conductor groove 5 is larger than the secondary conductor groove 4 located at the radial distance Ra from the center of the rotor 1.
Since the radial distance Rb is formed short, the interval L between the secondary conductor grooves 4 and 5 can be formed large, and the magnetic flux density can be reduced. In addition, the magnetic flux in the gap is made uniform by widening the gap between the stator and the rotor 1 because the magnetic flux becomes stronger toward the rotor portion closer to the opening 2 of the secondary conductor groove 4 near the outer circumference. The magnetic flux density can be reduced.

Effect of the Invention As is apparent from the above description of the embodiments, according to the present invention, since the secondary conductor grooves are arranged in a staggered pattern, the spacing between the secondary conductor grooves becomes large, and the magnetic flux density in the rotor is increased. In addition, the gap between the stator and the rotor is widened in the strong magnetic flux part and narrowed in the weak magnetic flux part to reduce the magnetic flux density in the gap and improve the efficiency, resulting in a large practical effect. Can provide a rotor.

[Brief description of drawings]

FIG. 1 is a front view of a rotor according to an embodiment of the present invention, FIG. 2 is an enlarged view of the secondary conductor groove portion, FIG. 3 is a front view of a conventional rotor, and FIG. It is an enlarged view of a conductor groove portion. 1 ...... Rotor, 2, 3 …… Secondary conductor groove opening, 4,5 …… Secondary conductor groove, Ra, Rb …… Radial distance, φDa, φDb …… Outer diameter dimension.

Claims (1)

[Scope of utility model registration request] 1. Circular secondary conductor grooves are arranged in a zigzag pattern in the vicinity of the outer circumference of the rotor so that the radial distances from the center of the rotor alternate, and the openings of the secondary conductor grooves near the outer circumference are formed. A rotor of an induction motor in which the outer diameter of the rotor in the portion close to the position is smaller than the outer diameter of the rotor in the portion close to the opening of the secondary conductor groove far from the outer circumference.