Rotor end-winding support for high-speed electrical machine such as a turbo-generator

• US 4,091,301 A
• Filed: 02/13/1976
• Issued: 05/23/1978
• Est. Priority Date: 07/08/1974
• Status: Expired due to Term

• Current Assignee: BBC Brown Boveri & Company Limited (ABB Limited)
• Original Assignee: BBC Brown Boveri & Company Limited (ABB Limited)
• Inventors: Blank, Karl
• Primary Examiner(s): Skudy, R.
• Application Number:
  US05/658,023
• Time in Patent Office: 830 Days
• Field of Search: 310/270, 310/262, 310/54, 310/261, 310/264, 310/269, 310/58, 310/59, 310/64, 310/260, 310/65, 310/265, 310/42, 310/43, 336/197
• US Class Current: 310/270
• CPC Class Codes: H02K 3/51 applicable to rotors only

Abstract

A rotor end-winding support for a high-speed electrical machine such as a turbogenerator in the form of an end bell which surrounds the end-winding and comprises two concentric rings. The inner ring made, for example, from a high-strength antimagnetic steel is shrunk into the rotor body and secured against axial displacement. The outer ring, made, for example, from a carbon-fibre-reinforced material or a nonmagnetic e.g. titanium alloy having a high ratio of strength to specific weight, is either shrunk onto the inner ring or expanded hydraulically to permit a slipover fit. The division of the end bell structure into a number of concentrically arranged components makes it possible to use combinations of materials, the respective component rings being allotted functions which correspond to their particular properties.

Claims

1. In a rotor end-winding support for a high-speed electrical machine, such as a turbogenerator, an overhung rotor end bell structure surrounding said end winding comprising an inner cylindrical ring extending over the entire axial length of said end winding and which is made from a high strength but easily machineable and shrinkable antimagnetic metallic material, one end of said inner ring being shrunk onto the body of the rotor at the axially inner end of said end-winding and the other end thereof surrounding the rotor shaft with radial clearance, an outer cylindrical ring extending over the entire axial length of said inner ring, said outer ring being made from an antimagnetic material of higher strength than said inner ring and having a high ratio of strength to specific weight, means for introduction of a pressurized hydraulic fluid into the interface between said inner and outer rings for expanding said outer ring to a diameter enabling it to be fitted upon said inner ring, and means for interlocking the end of said inner ring at the axially inner end of said end-winding with said rotor body.

2. A rotor end-winding support as defined in claim 1 wherein said inner cylindrical ring is made from an antimagnetic steel and said outer ring comprises titanium.

3. A rotor end-winding support as defined in claim 1 wherein said inner cylindrical ring is made from an antimagnetic steel and said outer ring is made from a carbon-fiber-reinforced material.

4. A rotor end-winding support as defined in claim 3 and which further includes a sheet of non-magnetic metal disposed between said inner and outer cylindrical rings.

8. A rotor end-winding support as defined in claim 1 wherein said means for introduction of a pressurized hydraulic fluid at the interface between said inner and outer rings for expanding said outer ring to a diameter enabling a fit upon said inner ring comprises fluid inlet bores communicating with surface slots in said inner ring.

5. In a rotor end-winding support for a high-speed electrical machine, such as a turbogenerator, an overhung rotor end bell structure surrounding said end-winding comprising an inner cylindrical ring extending over the entire axial length of said end-winding and which is made from a high strength, machinable antimagnetic material, one end of said inner ring being contracted onto the body of the rotor at the axially inner end of said end-winding and the other end thereof surrounding the rotor shaft with radial clearance, and an outer cylindrical ring extending over the entire axial length of said inner ring and which is force-fitted onto said inner ring, said outer ring being made from an antimagnetic material of higher strength than said inner ring and having a high ratio of strength to specific weight, and means for interlocking the inner end said inner ring with said rotor body to prevent any displacement thereof in an axial direction, said interlocking means comprising a series of circumferentially spaced and axially extending teeth provided on the end of said inner ring in alignment with and braced against a similar arrangement of teeth provided on the rotor body by a lockable bayonet ring, the junction between the toothed portions of said inner ring and rotor body being covered by said bayonet ring having a similar arrangement of internal teeth and which is installed on said inner ring by passing the teeth on the bayonet ring through the gaps formed between the aligned teeth on the inner ring and rotor body into a position wherein a shoulder portion of said bayonet ring engages the teeth on said inner ring and the teeth on said bayonet ring engage the teeth on said rotor body, said bayonet ring then being rotated into locking position which is reached when the teeth on the bayonet ring are in abutment with the teeth on the rotor body.

6. A rotor end-winding support as defined in claim 5 wherein said bayonet ring is made from a high-strength antimagnetic steel.

7. A rotor end-winding support as defined in claim 5 wherein said bayonet ring is contracted radially and axially against the braced parts of said teeth.