JPH022042Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the rotor of an induction motor, for example,
In particular, it relates to a cast-in squirrel cage rotor having ventilation ducts between laminated cores.

The rotor is installed inside to prevent temperature rise.
It is necessary to pass cooling air. For this purpose, a duct piece is constructed by stacking thin plates with holes or slots punched out, an iron core is assembled with this duct piece in between, and the iron core and duct piece are integrally formed by casting aluminum through the holes or slots. I am doing it.

FIG. 1 or 2 is a plan view of a conventional duct piece.

Duct pieces 101 or 201 having holes 102 or 202 bored in the center at a constant pitch on the inner circumferential side of a ring-shaped strip 100 or 200 are spaced apart from each other and the strip 100 or 200 is
Formed integrally with

Such thin iron plates are stacked, sandwiched between iron cores, aluminum is cast through the holes 102 or 202, and then the imaginary line 3
Or the strip 100 or 2 up to the position indicated by 8.
Scrape off 00 and attach duct piece 101 or 2
Divide 01 into individual parts.

This process is represented by the longitudinal cross-sectional view of the rotor shown in FIG.

11 is an outer diameter cut surface after casting, 12 is a laminated duct piece, and 13 and 14 are rotor cores that sandwich the duct piece.

By the way, when separating each duct piece by cutting the outer diameter of the rotor that has been integrated after casting, the surfaces 1, 2 or 6, 7 of the duct piece intersect at right angles to the outer diameter cutting surface 3 or 8. Therefore, large burrs occur at the cutting edges 4, 5 or 9, 10.

A large amount of man-hours are required to remove this burr. Further, if the removal of the burrs is incomplete or if small pieces of the removed burrs remain inside the rotor, this poses a serious problem in terms of the quality of the motor.

The object of the present invention is to provide a cast squirrel cage rotor that overcomes the conventional drawbacks, that is, does not cause burrs when cutting the outer diameter of the rotor.

FIG. 4 is a plan view of a duct piece in one embodiment of the present invention.

Moreover, FIG. 5 is a vertical cross-sectional view of the rotor which is integrated after casting.

Several dozen duct pieces 15 shaped after punching out a thin plate as shown in FIG. 4 are connected together on the inner circumferential side of the outer circumferential ring 19 to form a single piece. A laminated structure 20 is sandwiched between rotor cores 21 and 22, and hot water is poured into the rotor to form an integrated rotor.

After this, the outer diameter is cut and the duct piece 15 (4
01 is a hole into which aluminum is cast) is cut out to form a duct.

Therefore, in the present invention, the shape of this duct piece is curved surfaces 16 and 17 that are tangential to the outer cutting surface 18.

That is, in the present invention, at least the surface of the duct piece on the side opposite to the cutting direction, which intersects with the cutting surface, is formed into a curved surface inclined toward the side opposite to the cutting direction. As a result, burrs do not occur at all during outer diameter cutting.

By the way, the material of the duct piece 20 does not need to be an expensive material such as a silicon steel plate like the rotor cores 21 and 22, but may be made of an inexpensive material such as an iron plate, or may be a non-magnetic material instead of a magnetic material. .

6, 7, and 8 are plan views of duct pieces in other embodiments of the present invention.

In FIG. 6, a shape diagonally crossing the cutting surface 26, that is, sloped shapes 24 and 25 are formed.

Figures 7 and 8 show examples in which the cutting direction (cutting surface 29 or 32) is fixed, the cutting sides 28 and 31 (A is the cutting direction of the cutting tool) are made straight, and the cutting tool escapes. The side thereof is formed into a curved surface shape 27 or an inclined surface shape 30 that is inclined toward the side opposite to the cutting direction.

Even in these other embodiments of the present invention, no cutting burrs occur at all.

Thus, according to the present invention, no burrs occur in the duct portion during cutting of the outer diameter of the rotor after casting, so there is no need to remove the burrs at all, and the number of man-hours can be significantly reduced. Furthermore, since no burrs remain, quality problems can also be solved.

[Brief explanation of the drawing]

Figures 1 and 2 are plan views of the conventional duct piece, Figure 3 is a vertical cross-sectional view of its rotor, Figure 4 is a plan view of the duct piece of the present invention, and Figure 5 is a vertical cross-sectional view of its rotor. 6, 7, and 8 are plan views of duct pieces in other embodiments of the present invention. 12,15,20,101,201...Duct piece, 19,100,200...Outer ring,
13, 14, 21, 22...Rotor core, 1,
2, 6, 7... conventional duct piece surface, 16,
17, 24, 25, 27, 30... surface of the duct piece of the present proposal, 3, 8, 18, 23, 26, 29,
33... Cutting surface.

Claims (1)

[Scope of utility model registration request] A plurality of duct pieces are stacked and inserted at equal intervals on the inner circumference side of the outer ring between the rotor cores, which have multiple axial slots or holes on the outer circumference and are stacked in the axial direction. , in a cast squirrel cage rotor, in which the outer peripheral ring is shaved off after aluminum is cast into the slots or holes, the duct pieces are individually divided and radial ventilation ducts are formed; A cast-in squirrel cage rotor characterized in that a surface on the opposite side of the cut, which intersects with the cut surface, is formed into a curved surface or slope shape inclined toward the opposite side of the cut.