Electric generator system

March 6, 1962

3,024,366

MASANOSUKE YANAG1MACHI

ELECTRIC GENERATOR SYSTEM Filed June 11, 1958

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INVENTOR.

FIASAHOSUKE YAHAtslbtACUl BY

ATrOR.Ke'fS

United States Patent Office _p , J·⁰²⁴·³⁶⁶

Patented Mar. 6, 1962

3,024,366 ELECTRIC GENERATOR SYSTEM

Masanosuke Yanagimachi, 536 7-chome, Ebara, Shinagawa-ku, Tokyo, Japan

Filed June 11,1958, Ser. No. 741,249

Claims. (CI. 290—2)

This invention relates to an electric generator system.

In the prior art, electric generators have not been enclosed within a casing also enclosing a prime mover, due to the high electrical conductivity of the working substance, such as steam, for the prime mover. As a result, it has not been possible to effect a substantial reduction in the size of the overall electric generator system, and it has further been necessary to provide means for sealing the shaft of the prime mover which extends from the inside of the prime mover casing to the electric generator.

One object of this invention is to provide an electric generator and prime mover system which may be appreciably reduced in size.

Another object of this invention is to provide an electric generator which may be cooled easily and efficiently.

According to this invention, an electric generator is enclosed inside a casing together with a prime mover. The prime mover is an expanding fluid powered mechanism, such as a turbine in which a working substance may be expanded so as to drive the electric generator. The working substance is a dielectric, such as a member of a group of fluorinated hydrocarbons, for example, triChloromonofluoromethane commonly known by the trade name Freon-11, the dielectric constant of vapor of which is 1.0019 (26° C., 0.5 atm.).

The invention will be better understood and other objects and additional advantages of this invention will become apparent upon perusal of the following description taken in connection with the drawing, and the scope of the invention will be defined in the appended claims.

In describing the invention, reference will be made to the single FIGURE of the accompanying drawing in which the single FIGURE is an axial sectional view of a unit comprising a prime mover and an electric generator embodying this invention, together with a diagrammatic layout of pipe lines belonging to the unit.

Referring to the drawing, a casing 1 encloses a vapor turbine E, as a prime mover, and an electric generator D. The rotor 2 of the turbine E and the rotor 3 of the electric generator D are secured on a common shaft 4 which is journaled rotatably inside the casing 1. An inlet for a working substance F, for example, Freon-11, is provided through the wall of the casing 1 at the end thereof which faces the high pressure side of the turbine E, the low pressure side of the turbine E facing the electric generator D. Between the turbine E and the electric generator D, an outlet is provided through the wall of the casing 1 so as to exhaust the working substance F out of the casing 1. The exhausted working substance F is then admitted into a condenser C in which the same is cooled and condensed by cooling pipes 5. The liquefied working substance F is then delivered into a boiler B through a pump P. The boiler B vaporizes the working substance F so as to feed the vapor into the inlet of turbine E.

In the past, hydrogen gas has been used to cool electric generators. According to this invention, the working substance such as Freon-11 may be substituted for the hydrogen gas to cool the electric generator D in the following easy and simplified manner. The pipe line to circulate the working substance F may have a branch extending from a point between the pump P and the boiler B and directed to an opening provided through the end wall of the casing 1 remote from the turbine E. A part of the working substance F pumped may be fed into the electric generator D, being regulated by an expansion valve V provided in the branch line. The vapor of the working substance thus admitted inside the casing 1 at the end remote from the turbine E flows over the rotor 3 and the stator 6 of the electric generator D so as to cool the generator D. A fan 7 provided on the shaft 4 serves to exhaust the cooling vapor through the outlet, described hereinbefore, to the condenser C.

This invention may be adapted to a low-pressure cycle of a binary vapor cycle system for driving the electric generator. In such a case, the boiler B may be operated as a heat exchanger in which another working substance such as steam for the high-pressure cycle is condensed and the working substance such as Freon-11 for the lowpressure cycle is vaporised by the heat transferred from the condensing steam.

By virtue of the arrangement in accordance with this invention, it becomes possible to minimize the size of an electric generator system and eliminate the troublesome shaft seal problem. By virtue of the property of the specified working substance, the whole system may be kept thoroughly insulated electrically.

While particular embodiments of the invention have been illustrated and described, modifications thereof will readily occur to those skilled in the art. It should be understood therefore that the invention is not limited to the particular arrangements disclosed but that the appended claims are intended to cover all modifications which do not depart from the true spirit and scope of the invention.