HERMETICALLY SEALED DYNAMOELECTRIC MACHINE

• US 3,675,056 A
• Filed: 01/04/1971
• Issued: 07/04/1972
• Est. Priority Date: 01/04/1971
• Status: Expired due to Term

• Current Assignee: Henry George Lenz
• Original Assignee: Henry George Lenz
• Inventors: Lenz, Henry George
• Primary Examiner(s): Duggan, D. F.
• Application Number:
  US05/103,497
• Time in Patent Office: 547 Days
• Field of Search: 310/54-65
• US Class Current: 310/54
• CPC Class Codes: H02K 9/20 wherein the cooling medium vaporises within the machine casing
• CPC Class Codes: Y10S 174/19 in a dynamo-electric machine
• CPC Class Codes: Y10S 174/32 having means for cooling

Abstract

Effective spray cooling of the stator of a hermetically sealed motor is achieved without a reduction in stator flux carrying capacity by passing fluid refrigerant through triangularly shaped axial channels situated entirely within the stator teeth. Desirably, the edges of the channels are disposed parallel to the tapered faces of their associated teeth and the flux carrying area of each tooth is equal to the flux carrying area of the tooth face confronting the motor air gap. In one embodiment of the invention, entry of fluid refrigerant to the axial channels within the teeth is accomplished utilizing a diversely apertured annular manifold centrally positioned along the stator core and the refrigerant is withdrawn at both ends of the motor. Other refrigerant flow configurations, e.g., admitting the refrigerant at both ends of the motor and exhausting the refrigerant at the center or both ends of the motor, also are described.

Claims

1. In a dynamoelectric machine, the combination comprising a stator formed of a plurality of axially aligned magnetic laminations stacked to form a cylindrical bore for reception of a rotor therein, said laminations having a circular yoke and a plurality of teeth extending radially inward from said yoke to provide slots along the length of said stator for insertion of machine windings therein, each of said teeth exhibiting a gradually decreasing width with increased span from the stator yoke, and a triangularly shaped aperture situated entirely within each of said teeth at an attitude to provide a constant flux carrying area over the length of each of said teeth, the sides of said triangularly shaped apertures adjacent said slots being disposed parallel to the adjacent tapered sides of said tooth at an attitude to converge at the tooth face confronting said bore to produce a total flux carrying area within said tooth at any radial location along the struts formed between the aperture and said slots substantially equal to the flux carrying area of the tooth face confronting said cylindrical bore, and means for passing a fluid refrigerant through the triangularly shaped apertures in an axial direction.

2. A dynamoelectric machine according to claim 1 wherEin said means for passing fluid refrigerant through said triangularly shaped apertures comprises an annular manifold centrally disposed along the length of said stator and a plurality of orifices of diverse cross-sectional areas within said manifold to communicate said fluid refrigerant with the apertured stator teeth.

3. A dynamoelectric machine comprising a stator formed of a plurality of magnetic laminations stacked to form a cylindrical bore, each of said laminations having a completely homogeneous circular yoke and a plurality of teeth extending radially inward from said yoke to provide arcuately displaced slots extending the axial length of said stator, each of said teeth having tapered sides to produce parallel faces on adjacent teeth, machine windings disposed within said slots with the end turns of said windings protruding outwardly from the ends of the stacked laminations, an aperture situated entirely within each of said teeth, the sides of said aperture being parallel to the adjacent sides of said associated tooth at an attitude to converge at the center of the tooth face confronting said bore to provide a total flux carrying area at any radial location along the struts formed between said aperture and said slots substantially equal to the flux carrying area of the tooth face confronting said bore, means for passing a fluid refrigerant through said apertures in an axial direction, and a rotor disposed within said stator bore for electromagnetic interaction therewith.

4. A dynamoelectric machine according to claim 3 further including an axial channel within said rotor for the passage of fluid refrigerant therethrough, a first nozzle disposed in a substantially confronting attitude relative to said axial channel for propelling said fluid refrigerant toward said channel, a second nozzle situated at the end of said machine remote from said first nozzle, said second nozzle being disposed in a confronting attitude relative to said axial channel within said rotor and further including aligned radial passages extending through said stator and said rotor at the axial center of said machine for removal of fluid refrigerant from said machine.

5. A dynamoelectric machine according to claim 3 further including an axial channel within said rotor for the passage of fluid refrigerant therethrough, a first nozzle disposed in a substantially confronting attitude relative to said axial channel for propelling said fluid refrigerant toward said channel, a second fluid refrigerant inlet orifice situated along the length of said stator in communication with a radial zone extending through said stator laminations and a fluid refrigerant exhaust orifice situated at the end of said machine remote from said nozzle.

6. A dynamoelectric machine according to claim 5 wherein said radial zone extending through said stator laminations is in axial registration with a radial zone extending into said rotor and further including an axial passage extending the length of said stator.

7. In a dynamoelectric machine, the combination comprising a stator formed of a plurality of magnetic laminations stacked to form a cylindrical bore, said laminations having a circular yoke and a plurality of teeth extending radially inward from said yoke to provide axially extending slots along the length of said stator, a plurality of apertures situated within said magnetic laminations and extending at least partially within said teeth, a machine housing circumferentially enclosing said laminations, and an annular manifold disposed along the axial length of said stator to provide a liquid refrigerant reservoir between said manifold and housing extending to at least the center of said stator, said manifold having a plurality of orifices communicating said reservoir with said apertures in said stator teeth, the cross-sectional area of said orifices varying inversely with the height of said reservoir above each orifice.

8. A dynamoelectric machine according to claim 7 wherein said apertures within said tEeth are triangularly shaped and said manifold is further characterized by a plurality of radially inwardly extending plates spaced at arcuately displaced locations along said manifold.

9. A dynamoelectric machine according to claim 8 wherein said manifold has a diameter less than the diameter of said magnetic laminations, said plates are equal in number and arcuate displacement to said stator teeth and further including means within said plates for communicating areas disposed on opposite sides of said plates.