Rotor for electric machine having a sleeve with segmented layers

• US 8,247,938 B2
• Filed: 07/01/2009
• Issued: 08/21/2012
• Est. Priority Date: 07/28/2008
• Status: Active Grant

• Current Assignee: FMC Technologies Incorporated (TechnipFMC, plc)
• Original Assignee: Direct Drive Systems Inc. (TechnipFMC, plc)
• Inventors: Saban, Daniel M., Guedes-Pinto, Paulo
• Primary Examiner(s): NGUYEN, HANH N
• Application Number:
  US12/496,581
• Publication Number:
  US 20100019602A1
• Time in Patent Office: 1,147 Days
• Field of Search: 31015601-15684, 310/45, 295/96
• US Class Current: 310/156.28
• CPC Class Codes: H02K 1/02 characterised by the magnetic material
• CPC Class Codes: H02K 1/165 Shape, form or location of the slots
• CPC Class Codes: H02K 1/278 Surface mounted magnets; Inset magnets
• CPC Class Codes: H02K 15/12 Impregnating, heating or drying of windings, stators, rotors or machines
• CPC Class Codes: H02K 3/12 arranged in slots
• CPC Class Codes: H02K 3/24 with channels or ducts for cooling medium between the conductors
• CPC Class Codes: H02K 3/28 Layout of windings or of connections between windings windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32
• CPC Class Codes: H02K 3/487 Slot-closing devices
• CPC Class Codes: H02K 3/50 Fastening of winding heads, equalising connectors, or connections thereto
• CPC Class Codes: H02K 5/1285 of the submersible type
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/49012 Rotor

Abstract

A rotor for an electrical machine includes an elongate rotor core assembly comprising a rotor core and a plurality of permanent magnets arranged in a plurality of rings around the rotor core. A composite sleeve resides around the rotor core assembly. The sleeve includes an outer layer and a segmented layer beneath the outer layer. The outer layer includes a plurality of discrete, non-overlapping circumferential bands of composite material positioned orthogonal to a longitudinal axis of the rotor core assembly.

Claims

1. A rotor for an electrical machine comprising:

an elongate rotor core assembly adapted to rotate, during operation, around a central longitudinal axis, wherein the assembly has an outer surface;

a composite sleeve covering at least a portion of the rotor core assembly, the sleeve comprising;

a first layer of fiber-reinforced composite having a greater density of axially-oriented fibers than fibers of another orientation; and

at least one intermediate layer of fiber-reinforced composite having a greater density of fibers oriented substantially orthogonal to the longitudinal axis than fibers of another orientation, wherein the at least one intermediate layer is between the first layer and the outer surface of the rotor core assembly.

2. The rotor of claim 1, wherein the rotor core assembly is substantially cylindrical.

3. The rotor of claim 1, wherein the composite sleeve comprises a plurality of additional layers between the first layer and the outer surface of the rotor core assembly, each layer in the plurality of intermediate layers having a greater density of fibers oriented substantially orthogonal to the longitudinal axis than fibers of another orientation.

4. The rotor of claim 1, wherein the composite sleeve further comprises an innermost layer of fiber-reinforced composite between the at least one intermediate layer and the outer surface of the rotor core assembly, wherein the innermost layer has a greater density of axially-oriented fibers than fibers of another orientation.

5. The rotor of claim 1, wherein the fiber-reinforced composite of at least one of the first layer or at least one intermediate layer is carbon fiber.

6. The rotor of claim 1, wherein the rotor core assembly comprises a plurality of magnet segments.

7. The rotor of claim 6, wherein the composite sleeve covers at least the plurality of magnet segments on the rotor core assembly.

8. The rotor of claim 7, wherein the coefficient of thermal expansion of the fiber-reinforced composite of at least one of the first layer or at least one intermediate layer approximates the coefficient of thermal expansion of the plurality of magnet segments on the rotor core assembly.

9. The rotor of claim 1, wherein the composite sleeve is sealed to the rotor core assembly.

10. A composite sleeve adapted to cover a portion of an elongate rotor of an electrical machine having an outer surface, the sleeve comprising:

an outer layer of fiber-reinforced composite having a greater density of longitudinally-oriented fibers than fibers of another orientation; and

at least one inner layer of fiber-reinforced composite having a greater density of latitudinally-oriented fibers than fibers of another orientation, wherein the inner layer is between the outer surface of the rotor and the outer layer.

11. The sleeve of claim 10, further comprising an innermost layer of fiber-reinforced composite between the at least one inner layer and the outer surface of the rotor, wherein the innermost layer has a greater density of longitudinally-oriented fibers than fibers of another orientation.

12. The sleeve of claim 10, comprising a plurality of inner layers.

13. The sleeve of claim 10, wherein the coefficient of thermal expansion of the fiber-reinforced composite of at least one of the outer layer or at least one inner layer approximates the coefficient of thermal expansion of components on the elongate rotor.

14. The sleeve of claim 10, further comprising an outermost cosmetic layer.

15. The sleeve of claim 10, wherein the sleeve is adapted to cover the rotor during operation, wherein operation comprises rotation of the rotor around a central, longitudinal axis during operation.

16. The sleeve of claim 10, wherein the sleeve is adapted for deep-sea operation.

17. A method for retaining elements of an elongate electric machine rotor with a composite sleeve carried on the rotor, the method comprising:

limiting axial thermal expansion of the sleeve with at least one outer layer of fiber-reinforced composite having a greater density of longitudinally-oriented fibers than fibers of another orientation; and

radially reinforcing elements during rotation of the rotor with at least one inner layer of fiber-reinforced composite having a greater density of latitudinally-oriented fibers than fibers of another orientation, wherein the inner layer is between the outer surface of the rotor and the outer layer.

18. The method of claim 17, wherein axial thermal expansion of the sleeve is further limited by the at least one inner layer.

19. The method of claim 17, wherein axial thermal expansion of the sleeve is further limited by an innermost layer of fiber-reinforced composite between the at least one inner layer and the outer surface of the rotor, wherein the innermost layer has a greater density of longitudinally-oriented fibers than fibers of another orientation.