Guide vane assembly for reverse flow cooled dynamoelectric machine

• US 4,039,872 A
• Filed: 06/01/1976
• Issued: 08/02/1977
• Est. Priority Date: 06/01/1976
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Armor, Anthony F., Archibald, James B., Darby, William L.
• Primary Examiner(s): Skudy, R.
• Application Number:
  US05/691,363
• Time in Patent Office: 427 Days
• Field of Search: 310/52, 310/57, 310/53, 310/54, 310/55, 310/58, 310/59, 310/61, 310/62, 310/63, 310/64, 310/65, 310/260, 310/270
• US Class Current: 310/62
• CPC Class Codes: H02K 9/10 by gaseous cooling medium flowing in closed circuit, a part of which is external to the machine casing

Abstract

A reverse flow cooled dynamoelectric machine is provided with guide vanes and a guide vane mounting assembly comprising means for mounting and positioning the guide vanes, and means for directing the flow of cooling gas from the fan to the cooler. A fan nozzle ring is attached to the machine stator. An outer vane support ring is fixed to the fan nozzle ring and is provided with a circumferentially extending dovetail recess along its inner face. An inner vane support ring is spaced radially inwardly from the outer support ring and is also provided with a dovetail recess along its inner face. A plurality of guide vanes having inner and outer dovetail end portions mating with the dovetail recesses of the inner and outer support rings are held in place by the support rings. An annular rub strip is disposed adjacent to the outer support ring and is fixed to the fan nozzle ring. The rub strip includes a serrated inner face which, with the tips of the fan blades, produces a seal. A flow guide ring is provided adjacent the fan rub strip and acts to smoothly direct the flow of cooling gas away from the fan toward the cooler. The guide vanes and the mounting assembly are formed from electrically non-conducting materials to prevent induced heating of the assembly from stray flux at the end of the dynamoelectric machine.

Claims

1. A reverse flow dynamoelectric machine comprising

a. a stator assembly including a core having axially spaced radial cooling passages disposed therein;

b. a rotor disposed within the interior of said stator and defining therewith a circumferential gas gap;

c. a fan and guide vane assembly including;

c₁. at least one fan comprising a plurality of radial fan blades attached to said rotor and adapted to circulate cooling gas axially outwardly from said gas gap to a cooling means and therefrom to said stator and said gas gap;

c₂. at least one guide vane assembly disposed inboard of said fan and upstream thereof for directing cooling gas toward said fan with optimum efficiency and including;

c_2a. an outer guide vane support ring in fixed but removable relation to said stator assembly,

c_2b. a plurality of airfoil sectioned guide vanes depending inwardly from said outer guide vane support ring; and

c_2c. an inner guide vane support ring affixed to the inwardly depending ends of said guide vanes;

c₃. said guide vane assembly being fabricated from non-magnetic material incapable of supporting electrical currents and surrounding a portion of said rotor;

c₄. at least one removable annular fan rub ring affixed to said stator assembly surrounding the exterior of each said fan and in close proximity thereto sufficient to minimize gas flow leakage between said fan and said rub ring;

d. an annular flow guide ring affixed to said stator assembly downstream of the last fan affixed to said rotor and providing a portion of a smooth channel for providing a smooth gas flow downstream of said guide vane and said fan assembly.

2. The dynamoelectric machine of claim 1 wherein said guide vane assembly and rub ring are formed in a plurality of arcuate sections to provide for ease of assembly and disassembly.

3. The dynamoelectric machine of claim 1 wherein said guide vane assembly and said rub ring are affixed to said flow guide ring by means of a plurality of metallic non-magnetic fasteners binding upon metallic non-magnetic inserts bonded to apertures formed in said respective members to provide all metal-to-metal tensioning and the avoidance of any relaxation effects in said non-metallic members.

4. In a dynamoelectric machine of the type having a stator including a core, a rotor disposed within said core and defining with said stator a gas gap, the improvement comprising:

a. a fan and guide ring assembly for forcing cooling gas from said gas gap to a gas cooler and comprising at least one fan stage affixed to said rotor and adapted to force cooling gas axially outwardly from said gas gap and a guide vane assembly associated with and disposed upstream of said fan stage for directing cooling gas toward said fan stage with optimum efficiency;

b. said guide vane assembly comprising;

b₁. an outer guide vane support ring,

b₂. an inner guide vane support ring and

b₃. a plurality of airfoil shaped guide vanes supported radially with respect to the longitudinal axis of said rotor between said outer and inner support rings,

c. a fan nozzle ring affixed to said stator;

d. an annular rub ring circumferentially surrounding each of said fan stages and adapted in cooperation therewith to minimize gas leakage past said fan stage;

e. means fastening said rub ring and said guide vane assembly to the radially inner portion of said fan nozzle ring;

f. said fan nozzle ring and said guide vane assembly being formed of non-metallic, non-magnetic material incapable of sustaining electrical current.

5. The dynamoelectric machine of claim 4 wherein said means fastening said rub ring and said guide vane assembly includes a plurality of metallic non-magnetic bolts extending therethrough and binding upon metallic non-magnetic inserts and bushings bonded to apertures formed in said non-metallic members to provide a complete metal-to-metal fastening and thereby avoid any relaxation effects in said non-metallic members.

6. The dynamoelectric machine of claim 5 wherein said metallic fastening means are formed of stainless steel and chrome-copper.

7. The dynamoelectric machine of claim 5 wherein said guide vane assembly and said rub ring are formed in a plurality of arcuate segments for ease of assembly and disassembly.

8. the dynamoelectric machine of claim 5 wherein said fan and guide vane assembly includes a single fan stage and a single guide vane assembly.

9. The dynamoelectric machine of claim 5 wherein said fan and guide ring assembly includes a plurality of fan stages and an equal number of guide vane assemblies.