High strength induction machine, rotor, rotor cage end ring and bar joint, rotor end ring, and related methods

• US 20060273683A1
• Filed: 01/25/2006
• Published: 12/07/2006
• Est. Priority Date: 01/28/2005
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Caprio, Matthew T., Herbst, John, Jordon, Howard, Manifold, Stephen, Lelos, Vasileios
• Granted Patent: US 7,504,756 B2
• Time in Patent Office: Days
• US Class Current: 310/211
• CPC Class Codes: H02K 17/168 having single-cage rotors

Abstract

A high strength induction machine, rotor, rotor cage end ring and bar joint, rotor end ring, and related methods are provided. An embodiment of an end ring and bar joint includes a main body adapted to substantially surround a rotor shaft when mounted thereto, a plurality of slots extending inwardly in a radial direction from outer peripheries of the main body, a thicker end ring section extending outwardly from a medial portion of the main body, being thicker than the outer peripheries of the main body, and also being adapted to substantially surround the rotor shaft, and a plurality of bosses extending axially and outwardly from outer peripheral portions in a direction opposite to the thicker end ring section and each adapted to receive an end portion of a rotor bar therein.

Claims

1. An apparatus comprising

a stator having a stator frame, a stator core positioned in the stator frame, and a stator winding positioned in the stator frame;

and

a rotor associated with the stator and including a rotor shaft, a rotor cage assembly substantially surrounding at least portions of the rotor shaft, the rotor cage assembly including a rotor core having a plurality of laminations defining a stack, a plurality of rotor bars associated with the plurality of laminations, a pair of an end lamination plates positioned along opposing ends of the stack and associated with the plurality of rotor bars, a pair of end rings each positioned adjacent one of the pair of end lamination plates and connected to each of the plurality of rotor bars, and a pair of spacer plates each positioned between one of the pair of end lamination plates and one of the pair of end rings, each of the pair of end rings having a plurality of slots extending inwardly in a radial direction from outer peripheries of the end ring toward a medial portion of the end ring and a plurality of bosses extending axially and outwardly from outer peripheral potions toward one of the pair of end lamination plates, the medial portion of each of the pair of end rings including a thicker end ring section extending outwardly and axially away from the spacer plate and being thicker than the outer peripheral portions.

2. An apparatus as defined in claim 1, wherein each of the plurality of rotor bars has a substantially cylindrical shape, wherein each of the plurality of bosses of each of the pair of end rings also has a substantially cylindrical shape, and wherein each of the plurality of bosses has an end portion of one of the plurality of rotor bars positioned therein.

3. An apparatus as defined in claim 1, wherein each of the pair of end rings substantially surrounds the rotor shaft, wherein the thicker end ring section of the medial portion substantially surrounds the rotor shaft and is substantially solid, and wherein the outer peripheral portions of each of the pair of end rings is substantially solid other than the plurality of slots.

4. An apparatus as defined in claim 1, wherein each of the plurality of slots has a first slot portion extending inwardly from outer peripheries of the end ring and a second slot portion extending from the first slot portion and having a substantially annular shape so that the first and second slot portions in combination define a key-hole shape.

5. An apparatus as defined in claim 2, wherein each of the pair of end lamination plates has a plurality of annular-shaped openings extending along outer peripheries of the end lamination plate, each of the plurality of annular-shaped openings having one of the plurality of stator bars extending there through to coaxially align with one of the plurality of bosses associated with one of the pair of end rings.

6. A rotor for an induction machine, the rotor comprising:

a rotor shaft; and

a rotor cage assembly substantially surrounding at least portions of the rotor shaft, the rotor cage assembly including a rotor core having a plurality of laminations defining a stack, a plurality of rotor bars associated with the plurality of laminations, a pair of an end lamination plates positioned along opposing ends of the stack and associated with the plurality of rotor bars, a pair of end rings each positioned adjacent one of the pair of end lamination plates and connected to each of the plurality of rotor bars, and a pair of spacer plates each positioned between one of the pair of end lamination plates and one of the pair of end rings, each of the pair of end rings having a plurality of slots extending inwardly in a radial direction from outer peripheries of the end ring toward a medial portion of the end ring and a plurality of bosses extending axially and outwardly from outer peripheral potions toward one of the pair of end lamination plates, the medial portion of each of the pair of end rings including a thicker end ring section extending outwardly and axially away from the spacer plate and being thicker than the outer peripheral portions, the combination of one of the pair of end lamination plates, one of the pair of spacer plates, and one of the pair of end rings having the plurality of bosses defining an end ring and bar joint of the rotor.

7. A rotor as defined in claim 6, wherein each of the plurality of rotor bars has a substantially cylindrical shape, wherein each of the plurality of bosses of each of the pair of end rings also has a substantially cylindrical shape, and wherein each of the plurality of bosses has an end portion of one of the plurality of rotor bars positioned therein.

8. A rotor as defined in claim 7, wherein each of the pair of end rings substantially surrounds the rotor shaft, wherein the thicker end ring section of the medial portion substantially surrounds the rotor shaft and is substantially solid, and wherein the outer peripheral portions of each of the pair of end rings is substantially solid other than the plurality of slots.

9. A rotor as defined in claim 8, wherein each of the plurality of slots has a first slot portion extending inwardly from outer peripheries of the end ring and a second slot portion extending from the first slot portion and having a substantially annular shape so that the first and second slot portions in combination define a key-hole shape.

10. A rotor as defined in claim 9, wherein each of the pair of end lamination plates has a plurality of annular-shaped openings extending along outer peripheries of the end lamination plate, each of the plurality of annular-shaped openings having one of the plurality of stator bars extending there through to coaxially align with one of the plurality of bosses associated with one of the pair of end rings.

11. An end ring for a rotor of an induction machine, the end ring comprising:

a main body adapted to substantially surround a rotor shaft when mounted thereto;

a plurality of slots extending inwardly in a radial direction from outer peripheries of the main body;

a thicker end ring section extending outwardly from a medial portion of the main body, being thicker than the outer peripheries of the main body, and also being adapted to substantially surround the rotor shaft; and

a plurality of bosses extending axially and outwardly from outer peripheral portions in a direction opposite to the thicker end ring section and each adapted to receive an end portion of a rotor bar therein.

12. An end ring as defined in claim 11, wherein each of the plurality of bosses has a substantially cylindrical shape and is adapted to receive one of the plurality of substantially cylindrical shaped rotor bars associated with a rotor therein.

13. An end ring as defined in claim 11, wherein the thicker end ring section is substantially solid, and wherein the outer peripheral portions of the main body is substantially solid other than the plurality of slots.

14. An end ring as defined in claim 11, wherein each of the plurality of slots has a first slot portion extending inwardly from outer peripheries of the end ring and a second slot portion extending from the first slot portion and having a substantially annular shape so that the first and second slot portions in combination define a key-hole shape.

15. A method of assembling a rotor, the method comprising:

positioning a plurality of substantially cylindrical shaped rotor bars through a plurality of laminations which define a stack and to substantially surround a rotor shaft so that end portions of each of the plurality of rotor bars extends outwardly from opposing ends of the stack;

positioning an end lamination plate having a plurality of annular-shaped openings extending along outer peripheries thereof onto each of the end portions of the plurality of rotor bars;

positioning an end ring including a plurality of bosses extending outwardly toward the end lamination plate along opposing ends of the stack so that each of the plurality of bosses receives an end portion of one of the plurality of rotor bars; and

positioning a spacer plate between each of the end lamination plate and the end ring positioned along the opposing ends of the stack.

16. A method as defined in claim 15, wherein each end ring further includes a main body adapted to substantially surround a rotor shaft when mounted thereto, a plurality of slots extending inwardly in a radial direction from outer peripheries of the main body, and a thicker end ring section extending outwardly from a medial portion of the main body, being thicker than the outer peripheries of the main body, and also being adapted to substantially surround the rotor shaft.

17. A method of operating a rotor of a machine, the method comprising:

positioning at least one end ring and bar joint having an end ring on an end of a plurality of laminations defining a stack of a rotor core of a rotor so that the end ring connected to a plurality of rotor bars is substantially supported by a rotor shaft extending through the end ring when the rotor core rotates rather than the plurality of rotor bars; and

driving the rotor core at a relatively high speed.

18. A method as defined in claim 17, wherein the at least one end ring and bar joint further includes a spacer positioned between the end ring and an end lamination of the rotor core.

19. A method as defined in claim 17, wherein the end ring further has a non-uniform thickness, and wherein a thicker section of the end ring interfaces with the rotor shaft to bear a substantial amount of the end ring load.

20. A method as defined in claim 17, wherein the end ring further has a plurality of end ring bosses positioned spaced-apart along out peripheries of the end ring, and the method further comprising inserting end potions of each of the plurality of rotor bars into a corresponding one of the plurality of end ring bosses and connecting the inserted end portions of the rotor bars to the end ring prior to the step of driving the rotor.