Electrical generator or motor structure – Dynamoelectric – Rotary
Patent
1983-05-06
1984-11-27
Budd, Mark O.
Electrical generator or motor structure
Dynamoelectric
Rotary
310 42, 310259, H02K 116, H02K 118
Patent
active
044853203
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
TECHNICAL FIELD
The present invention relates to a stator, more particularly, to a stator comprising a laminated iron-core of a rotary machine such as an electric motor, and end plates and a frame which held the iron-core.
BACKGROUND ART
An electric motor generally comprises a rotor, stator, and casing. The stator comprises a laminated iron-core (laminated core of silicon steel plates) and end plates and a casing which fasten the laminated core. As the casing a cast casing provided with cooling fins is used. Miniaturization, direct iron-core cooling, and cost reduction considerations, however, have resulted in development of electric motors without cast casing and with exposed iron-cores. The elimination of cast casing and other casings, however, makes laminated iron-core susceptible to deformation by sliding of the laminated plates. Accordingly, it is necessary to provide a means for securely fastening a laminated iron-core. Methods of fastening include the method of boring holes through the laminating iron-core (laminated silicon steel plates) and of binding it with bolts and the method of making longitudinal grooves for welding in the outer periphery of the laminated iron-core and performing arc welding. In the former case, there is the danger of twisting of the laminated iron-core. In the latter case, there is the danger of unsecure joining of the steel plates constituting the laminated iron-core. Attempts have been made to securely fasten the laminated iron-core by forming square longitudinal grooves in its outer periphery, inserting square bars into the square grooves by, e.g., hammering, and then welding together the laminated iron-core and square bars. In this case, during the arc welding process, the still unwelded end portions of the square bars bend up and rise over the outer surface of the iron-core due to thermal deformation. This makes it necessary to remove the risen end portions of the square bars by machining. Furthermore, the weld strength of the weld zone including the machined portions of the square bar is thus lower than that of the weld zone including the rest of the square bar.
DISCLOSURE OF THE INVENTION
An object of the present invention is to prevent bending and rising due to thermal deformation during welding of a laminated iron-core of a stator with bars inserted into grooves formed in the iron-core.
Another object of the present invention is to provide a stator of an electric motor having an exposed laminated iron-core fastened securely without deformation.
The above-mentioned objects are attained by a stator comprising a laminated iron-core with windings, end plates parallel to the lamination planes of the iron-core, and a frame formed on the outer periphery of the iron-core. According to the present invention, the frame comprises steel bars having a trapezoidal shape in cross-section, dovetail grooves which accommodate the steel bars are formed in the laminated iron-core, and the steel bars and the laminated core and end plates are welded.
It is preferable that the cross-section of the steel bars be an equilateral trapezoid. It is also preferable to bevel the edges of the laminated iron-core at the dovetail grooves so as to form V-grooves for welding by the steel bars and the laminated iron-core.
There are at least two steel bars comprising the frame. It is preferable to arrange the steel bars symmetrically with respect to the center axis of the stator. Furthermore, it is preferable that the steel bars be made of non-magnetic steel, for example, stainless steel (SUS 304), in which no eddy current is generated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of a stator according to the present invention; and
FIG. 2 is a partial sectional view of the stator of FIG. 1.
BEST MODE FOR CARRYING OUT THE INVENTION
As illustrated in FIG. 1, a stator of a rotary machine according to the present invention comprises a laminated iron-core 1, end plates 2, and steel bars 3 serving as a frame. The laminated iron-core 1 is formed by lamin
REFERENCES:
patent: 2393065 (1946-01-01), Rose
patent: 2556013 (1951-06-01), Thomas
patent: 2610225 (1952-09-01), Korski
patent: 2790918 (1957-04-01), Goran
patent: 2961556 (1960-11-01), Vance
patent: 3533867 (1970-10-01), Derzee
Kawada Shigeki
Nakamura Kousei
Nakano Jiro
Oyama Shigeaki
Budd Mark O.
Fanuc Ltd.
LandOfFree
Welded stator using non-magnetic bars in specially shaped lamina does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Welded stator using non-magnetic bars in specially shaped lamina, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Welded stator using non-magnetic bars in specially shaped lamina will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2136166