Electric machine, stator assembly for an electric machine, and method of manufacturing the same

• US 7,687,965 B2
• Filed: 04/13/2007
• Issued: 03/30/2010
• Est. Priority Date: 04/13/2006
• Status: Expired due to Fees

• Current Assignee: Regal Beloit Epc Inc. (Regal Rexnord Corp.)
• Original Assignee: A. O. Smith Corporation
• Inventors: Lesak, Alan E., Ionel, Dan M.
• Primary Examiner(s): Leung; Quyen
• Assistant Examiner(s): Kim; John K
• Application Number:
  US11/734,901
• Publication Number:
  US 20070241629A1
• Time in Patent Office: 1,082 Days
• Field of Search: 310/172, 310/216, 310/259, 310/68.R, 310/216.036, 310/216.037, 310/216.038
• US Class Current: 310/216.037
• CPC Class Codes: H02K 1/141 consisting of C-shaped cores
• CPC Class Codes: H02K 1/143 of the horse-shoe type
• CPC Class Codes: H02K 1/146 consisting of a generally annular yoke with salient poles
• CPC Class Codes: H02K 21/185 with the axis of the rotor perpendicular to the plane of the armature
• CPC Class Codes: H02K 3/487 Slot-closing devices
• CPC Class Codes: H02K 5/15 Mounting arrangements for bearing-shields or end plates
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine

Abstract

A stator for a motor having a rotor includes a plurality of laminations each formed in a first elongated arrangement. Each lamination includes a first leg, a second leg, and an intermediate portion that are configured to be rearranged and stacked in a stackwise direction to define a core having a second U-shaped arrangement. A coil is coupled to the first leg.

Claims

1. A stator for a motor having a rotor, the stator comprising:

a first leg including a first curved portion and a first substantially straight portion that define a first length;

a coil coupled to the first leg;

a second leg formed as a separate piece from the first leg, the second leg including a second curved portion and a second substantially straight portion that define a second length; and

an intermediate portion formed as a separate piece from the first leg and the second leg and having a third length, the first leg, the second leg, and the intermediate portion connected to one another to at least partially define a U-shaped magnetic circuit, wherein the first leg, the second leg, and the intermediate portion each have a substantially constant and equal width along the first length, the second length, and the third length, wherein the first curved portion includes a substantially circular arched inside surface that defines an inside diameter and a substantially circular arched outside surface that defines an outside diameter that is about equal to the inside diameter, and wherein during forming, the circular arched outside surface is arranged to nest within a circular arched inside surface of an adjacent first leg when the first substantially straight portion is parallel to a substantially straight portion of the adjacent first leg.

2. The stator of claim 1, wherein the second curved portion includes a substantially circular inside surface that defines an inside diameter and a substantially circular outside surface that defines an outside diameter that is about equal to the inside diameter, and wherein the first curved portion and the second curved portion cooperate to surround at least 65 percent of a circumference of the rotor.

3. The stator of claim 1, further comprising a first bridge coupled to the first leg and the second leg, and a second bridge coupled to the first leg and the second leg, the first curved portion, the second curved portion, the first bridge, and the second bridge completely surrounding the circumference of the rotor.

4. The stator of claim 1, further comprising a bridge member coupled to the first leg and the second leg.

5. The stator of claim 4, wherein the bridge defines a width and wherein the bridge includes a corrugation that extends along a portion of the width.

6. The stator of claim 4, wherein the bridge defines a length and wherein the bridge includes a slot that extends along a portion of the length.

7. The stator of claim 6, wherein the bridge includes a second slot that is substantially parallel to the slot.

8. The stator of claim 1, wherein the first leg, the second leg, and the intermediate portion are formed from a plurality of laminations.

9. The stator of claim 8, wherein each of a portion of the plurality of laminations defines a notch, and wherein the notches cooperate to define a space, and wherein a capacitor is disposed within the space.

10. The stator of claim 8, wherein each lamination defines a lamination width and a length, and wherein the width is substantially uniform along the length.

11. The stator of claim 8, wherein each lamination is simultaneously formed as three separate pieces.

12. The stator of claim 11, wherein the first leg, the intermediate portion, and the second leg cooperate to define a substantially straight portion that extends along an axis, and wherein the first leg and the intermediate portion are separated by a first cut line and the second leg and the intermediate portion are separated by a second cut line, the first cut line and the second cut line arranged to define an angle of about 45 degrees with respect to the axis and to be substantially perpendicular to one another.

13. The stator of claim 1, further comprising a first locking member configured to connect the first leg to the intermediate portion and a second locking member configured to connect the second leg to the intermediate portion.

14. The stator of claim 1, further comprising a first bridge portion and a second bridge portion coupled to the first leg and the second leg, the first bridge portion stacked on top of the second bridge portion to define a stacked bridge arrangement.

15. The stator of claim 1, wherein the first leg, the intermediate portion, and the second leg cooperate to define a grain structure oriented in a U-shaped direction when the first leg, the intermediate portion, and the second leg are arranged in a U-shaped arrangement.