DYNAMOELECTRIC MACHINE COOLED BY A ROTATING HEAT PIPE

• US 3,715,610 A
• Filed: 03/07/1972
• Issued: 02/06/1973
• Est. Priority Date: 03/07/1972
• Status: Expired due to Term

• Current Assignee: William Guy Brinkman
• Original Assignee: William Guy Brinkman
• Inventors: Brinkman, William Guy
• Primary Examiner(s): Skudy, R.
• Application Number:
  US05/232,385
• Time in Patent Office: 336 Days
• Field of Search: 310/54,52,53,55,56,57,58,59,60,64,65
• US Class Current: 310/54
• CPC Class Codes: F28D 15/0208 using moving tubes
• CPC Class Codes: H02K 9/225 Heat pipes

Abstract

A dynamoelectric machine is described wherein heat generated within the rotor is removed utilizing a heat pipe rotating about the rotor shaft. Heat is absorbed from the rotor by vaporization of a portion of the refrigerant within a rectangular evaporator juxtaposed with the heat generating region of the rotor whereafter the vaporized refrigerant flows radially inward (due to centrifugal forces acting upon the higher density liquid refrigerant) to pass to a condenser coil secured to the rotor at a relatively cool location. Upon cooling to a liquid state in the condenser, the liquid refrigerant is forced radially outward along the condenser coil to return to the evaporator through a radially outer orifice. Preferably, the evaporator is situated within the rotor coils, e.g., at the center of the field pole winding of a synchronous machine, although the evaporator also could be positioned along any radially extending side of the rotor coil. Because refrigerant passes from the evaporator to the condenser and returns to the evaporator solely by centrifugal forces acting upon the closed cooling system, a separate refrigerant pump is not required to cool the motor.

Claims

1. In a dynamoelectric machine characterized by a rotor, a stator and at least one coil formed of an electrical conductor multiply wound into a plurality of substantially closed loops upon said rotor to rotate therewith, the improvement comprising a radially elongated evaporator disposed within said coil to rotate about the axis of said rotor, said evaporator containing fluid refrigerant vaporizable at a temperature Below the maximum operating temperature of said coil at the total pressure upon said refrigerant in a liquid state at the normal operating speed of said machine to remove heat from said coil by conversion of said refrigerant from a liquid to a gaseous state, a condenser suitable outside said coil within an environment sufficiently cool to convert gaseous refrigerant to a liquid state, means interconnecting said evaporator and said condenser to permit gaseous refrigerant formed by absorption of heat from said coil to exit from a radially inward orifice of said evaporator to said condenser and means for returning condensed liquid refrigerant from said condenser to a radially outer orifice of said evaporator by the centrifugal forces acting upon said liquid refrigerant.

2. A dynamoelectric machine according to claim 1 wherein said evaporator has a radial height in excess of 50 percent of the radial height of the coil wherein said evaporator is located, the width of said evaporator in the direction of rotor rotation being less than 20 percent of the evaporator height.

3. A dynamoelectric machine according to claim 2 wherein said machine is a synchronous machine, an evaporator is situated on each side of the field poles of the synchronous machine and the condensers associated with evaporator on opposite sides of a given field pole are located at axially opposite ends of the machine.

4. A dynamoelectric machine comprising a cylindrical stator, a rotor journaled at both ends to rotate within said stator, a plurality of field poles extending radially outward from said rotor, field pole windings formed of an insulated conductor multiply wound about the body of said field poles, a radially elongated evaporator having a height to width ratio in excess of 5:

1 disposed within said field pole winding, said evaporator containing a fluid refrigerant vaporizable at a temperature below the maximum operating temperature of said field winding at the total pressure upon said refrigerant in a liquid state at the normal operating speed of said machine, a condenser disposed outside said coil within an environment sufficiently cool to convert refrigerant in a gaseous state to a liquid, means interconnecting said evaporator and said condenser to permit refrigerant vapor formed by absorption of heat from said coil to exit from a radially inward orifice of the evaporator to said condenser and means for returning by centrifugal force condensed liquid refrigerant from said condenser to a radially outer orifice of said evaporator.

5. A dynamoelectric machine according to claim 4 wherein said condenser is a coil formed of a plurality of helical turns, said coil having a radial taper away from the rotor axis along the length of the coil to move condensed refrigerant by centrifugal force from the condenser to the liquid refrigerant return orifice of said evaporator.

6. A dynamoelectric machine according to claim 5 wherein said condenser is cooled by the flow of air thereacross, said air entering the end of said machine adjacent said condenser and being exhausted from the same end of said machine after cooling of said coil without passage through said machine.

7. A dynamoelectric machine comprising a stationary member, a rotatable member producing heat in quantities tending to limit performance of said machine, a heat pipe in thermal contact with said rotatable member to absorb heat therefrom by the vaporization of a liquid refrigerant contained within said heat pipe, said vaporized refrigerant flowing through a radially inward exhaust orifice due to the centrifugal forces acting upon the refrigerant system to pass to a rotating condenser fixedly secured along said rotor at a location remote from the heat generating source, said condenser being situated in a sufficiently cool environment to condense refrigerant vapor to a liquid state and means connecting said condenser to said evaporator to permit centrifugal force to return condensed liquid refrigerant from said condenser to a rAdially outer intake orifice of said evaporator to repeat the thermal cycle.