Cantilever spring contact for retaining rings on dynamoelectric machine

• US 5,118,979 A
• Filed: 12/18/1990
• Issued: 06/02/1992
• Est. Priority Date: 12/18/1990
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Hopeck, James F., Shih, True T.
• Primary Examiner(s): Skudy, R.
• Application Number:
  US07/628,898
• Time in Patent Office: 532 Days
• Field of Search: 310/261, 310/42, 310/214, 310/270, 310/105, 310/260, 310/198
• US Class Current: 310/214
• CPC Class Codes: H02K 3/51 applicable to rotors only

Abstract

In a dynamoelectric generator, a low-resistance electrical contact is provided by a cantilever beam mounted between the outer surface of the rotor body and an overlapping retaining ring. This cantilever beam is part of the wedges in the rotor body and provides a conductive current path for high-frequency eddy currents induced on the surface of the rotor and retaining rings at all operating speeds.

Claims

1. A dynamoelectric machine comprising:

a rotor body having a plurality of longitudinal slots in its outer surface;

electrically-conductive windings having longitudinal sections located in said slots and end turns connecting said longitudinal sections and said end turns extending axially out from said rotor body;

wedges in said rotor slots confining said longitudinal sections in said slots, at least one wedge having a cantilever beam;

a retaining ring attached to an axial end of said rotor body, said retaining ring enclosing said end turns to restrain radial outward movement of the end turns, said retaining ring overlapping said cantilever beam of at least one wedge and clamping onto said cantilever beam to form a low-resistance electrical contact between the wedge and retaining ring.

2. A dynamoelectric machine as in claim 1 wherein said rotor body and said wedges comprise eddy current shields, and the contact between the retaining ring and the cantilever beam providing a conductive electrical path for facilitating eddy currents from said eddy current shields on the rotor body to the retaining ring at all operating speeds.

3. A dynamoelectric machine as in claim 2 wherein at least one of said eddy current shields covering an outer surface of said retaining ring.

4. A dynamoelectric machine as in claim 1 wherein said cantilever beam is a separable component of the wedge.

5. A dynamoelectric machine comprising:

a rotor body having a plurality of longitudinal slots in its outer surface;

electrically-conductive windings having longitudinal sections located in said slots and end turns connecting said longitudinal sections and extending axially out from said rotor body;

wedges in said rotor slots above the longitudinal sections of said windings and confining said longitudinal sections in said slots, at least one wedge having an integral cantilever beam at its surface;

a retaining ring attached to an axial end of said rotor body, said retaining ring enclosing said end turns to restrain radial outward movement of the end turns, said retaining ring overlapping said cantilever beam of at least one of said wedges and clamping onto said cantilever beam to form a low-resistance electrical contact between the wedge and retaining ring.

6. In a dynamoelectric machine comprising:

a cylindrical rotor body having a plurality of longitudinal rotor slots in its outer surface;

electrically-conductive windings having longitudinal sections in said rotor slots and end turns electrically coupling said longitudinal sections in a plurality of said slots, said end turns adjacent an axial end of said rotor body;

wedges in said rotor slots above said windings, said wedges confining the longitudinal sections of said windings in their respective slots, said wedges comprising an eddy current shield on an outer surface, a cantilever beam towards an end of at least one of said wedges, and a protruding end section extending radially outward of said rotor body and the cantilever beam;

a retaining ring secured to an axial end of said rotor body and enclosing said end turns, said retaining ring overlapping the cantilever beam and said end of of said wedges, said retaining ring comprising an eddy current shield at the outer surface of said retaining ring and an annular array of nose teeth at an inner periphery of said retaining ring, said nose teeth extending radially inwardly of said protruding end section of said wedge and of at least one of the wedges and being aligned with said wedges when mounted on said rotor body;

wherein said nose teeth clamping down on said cantilever beam and said cantilever beam being biased against said nose teeth to provide a low resistance coupling for high-frequency currents between the wedges and retaining ring.