Electrical generator or motor structure – Dynamoelectric – Rotary
Patent
1993-05-28
1995-09-05
LaBalle, Clayton E.
Electrical generator or motor structure
Dynamoelectric
Rotary
310 58, 310 64, 310 89, H02K 919, H02K 900, H02K 120, H02K 520
Patent
active
054481180
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid cooling structure of an electric motor such as an induction motor, and more particularly, to a jacket for cooling a stator and a method of manufacturing the same and an improvement in the structure of a liquid cooled motor using the jacket.
2. Description of the Related Art
For the purpose of enhancing the cooling efficiency in an electric motor and relieving the peripheral equipment from being adversely affected by heat dissipation, there has been proposed a liquid cooled motor which includes a casing 1 having liquid cooling conduits 2, which serves as a cooling jacket for a stator 3, as shown in FIGS. 3 (PRIOR ART) and 4 (PRIOR ART).
In this case, the casing 1 is usually sand-cast from aluminum alloy, and housings 4 and 5 are separately attached to the front and rear surfaces, respectively, of the casing 1 by ordinary bolts. This entails the following problems.
Due to characteristics of the casting, the wall portions of the casing 1, inevitably involve cavities 7 in the interior or on the surface thereof, which may cause liquid leakage if the casing 1 is used as the liquid cooling structure. In particular, the cavities 7 are liable to be exposed on the inner surface or the end surface which has been subjected to cutting operations, thereby causing the leak of the coolant. In order to fill the cavities 7, there may be needed, for example, a time-consuming and costly treatment requiring casing 1 to be dipped into the special sealing compound after being cast.
It is also impossible to provide the sand-casting with deep holes and threaded holes having an accurate configuration by the sand-casting process alone. Hence, if they are needed, the sand-casting must be subjected to further cutting operation after casting. In addition, due to the impossibility of obtaining a higher dimensional accuracy, a fine or complicated sectional configuration is unable to be provided on the interior of the liquid cooling conduits 2.
Further, at least eight ordinary bolts 6 must be used to fasten the front and rear housings to the casing 1, involving a large number of assembling steps which not only may cause an unevenness in the screw torque of the bolts 6 but also requires a greater precaution to ensure a uniform fastening.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a liquid cooled motor and its jacket presenting a higher reliability with respect to liquid leakage and less assembling steps and an improved cooling efficiency.
In order to achieve the above object, the present invention comprises the steps of extruding a billet of aluminum alloy so as to provide conduits therein for the passage of coolant, and cutting the extruded billet into a desired length to obtain a jacket serving as a stator cooling jacket, which also serves as a casing.
A liquid cooled motor according to the present invention comprises the stator cooling jacket having front and rear surfaces, a front housing attached to the front surface, and a rear housing attached to the rear surface, the jacket and the front and rear housings being fastened together by means of a plurality of tie bolts extending from the front housing to the rear housing.
Preferably, the front and rear housings are made of cast iron and respectively include flanges having a plurality of holes through which the tie bolts are allowed to pass and a plurality of threaded holes for receiving threaded end portions of the tie bolts, respectively.
Preferably, the jacket includes a plurality of thickness lightening holes formed, when extruding the jacket for cooling a stator, and used as holes through which the tie bolts are allowed to pass.
Preferably, each of the plurality of thickness lightening holes have a sectional configuration a part of which permits only the axial displacement of the tie bolt inserted into the thickness lighting holes.
Preferably, the plurality of thickness lightening holes are equally spaced in the circumferential direction of
REFERENCES:
patent: 2700115 (1955-01-01), Mowery, Jr.
patent: 3255517 (1966-06-01), Barbera
patent: 3748507 (1973-07-01), Sieber
patent: 3882334 (1975-05-01), Newill
patent: 4463057 (1984-07-01), Knurr
patent: 4691131 (1987-09-01), Nakano
patent: 4745314 (1988-05-01), Nakano
patent: 4908538 (1990-03-01), Geberth, Jr.
patent: 5084642 (1992-01-01), Katsuzawa et al.
patent: 5229673 (1993-07-01), Katsuzawa et al.
Katsuzawa Yukio
Masuya Michi
Nakamura Kosei
Fanuc Limited
LaBalle Clayton E.
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