Structure and method of rotor assembly without the hub

• US 20070096584A1
• Filed: 10/31/2005
• Published: 05/03/2007
• Est. Priority Date: 10/31/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Erfanfar, Mohsen
• Granted Patent: US 7,546,674 B2
• Time in Patent Office: Days
• US Class Current: 310/216.015
• CPC Class Codes: H02K 1/26 Rotor cores with slots for windings
• CPC Class Codes: H02K 1/30 using intermediate parts, e.g. spiders
• CPC Class Codes: H02K 15/028 for fastening to casing or support, respectively to shaft or hub
• CPC Class Codes: Y10T 29/49012 Rotor

Abstract

A structure and method of assembling a rotor assembly is provided, without the use of a rotor steel hub. The method comprises forming first, second and third lamination stacks by stacking individual rotor laminations together. The first, second and third lamination stacks are cast to lock the individual rotor laminations together. The rotor laminations in the first, second and third lamination stacks have a generally ring-like shape with a variable inner diameter and a substantially common outer diameter. The rotor laminations in the first, second and third lamination stacks have substantially the same outer diameter, whereas the rotor laminations in the second lamination stack have a substantially larger inner diameter than the first and third rotor laminations. The elimination of the hub results in reducing total cost and manufacturing cycle time, and in improved features, performance and efficiency of the rotor assembly.

Claims

1. A method of rotor assembly comprising:

stacking first rotor laminations sufficiently to create a first lamination stack, wherein said first lamination stack has a first end and a second end;

stacking second rotor laminations sufficiently onto said second end of said first lamination stack thereby creating a second lamination stack, wherein said second lamination stack has a first end and a second end;

stacking third rotor laminations sufficiently onto said second end of said second lamination stack thereby creating a third lamination stack, wherein said third lamination stack has a first end and a second end;

casting said first, second and third lamination stacks to lock said first, second and third rotor laminations together;

wherein said first, second and third rotor laminations have a shape with a variable inner diameter and a substantially common outer diameter;

wherein said first, second and third rotor laminations have substantially the same outer diameter; and

wherein said second rotor laminations have a larger inner diameter than said first and third rotor laminations.

2. The method of claim 1, wherein said shape of said first, second and third rotor laminations is a ring shape, having an outer and inner circumference.

3. The method of claim 2, wherein slots extend along periphery of outer circumference of said first, second and third rotor laminations.

4. The method of claim 3, wherein said casting of said first, second and third lamination stacks comprises:

placing said first, second and third lamination stacks in a die cast mold fixture;

molding said first, second and third lamination stacks by applying pressure to lock said first, second and third lamination stacks together;

injecting molten metal into said slots extending along periphery of outer circumference of said first, second and third rotor laminations, wherein said molten metal is injected from said first end of said first lamination stack to said second end of said third lamination stack; and

applying hydraulic back pressure against said molten metal to avoid air gaps, bubbles or porosity inside said first, second and third lamination stacks.

5. The method of claim 4,

wherein said molten metal through said die cast mold fixture solidifies at said first end of said first lamination stack to create a first metal end ring;

and

wherein said molten material through said slots solidifies at said second end of said third lamination stack to create a second metal end ring on the opposite end of said rotor assembly.

6. The method of claim 1, further comprising the steps of:

attaching a first bolt onto said first lamination stack;

attaching a second bolt onto said third lamination stack;

attaching a first flange onto said first end of said first lamination stack, using said first bolt for orientation; and

attaching a second flange onto said second end of said third lamination stack, using said second bolt for orientation.

7. The method of claim 1, wherein at least one guide bar is used to align said stacking of said first, second and third lamination stacks in said die cast mold fixture prior to molding.

8. The method of claim 1, wherein said first and said third rotor laminations number approximately 25.

9. The method of claim 1, wherein said second rotor laminations number approximately 220.

10. A rotor assembly comprising:

a first lamination stack comprised of first rotor laminations, wherein said first lamination stack has a first end and a second end;

a second lamination stack attached onto said second end of said first lamination stack, wherein said second lamination stack is comprised of second rotor laminations, wherein said second lamination stack has a first end and a second end;

wherein said first and second lamination stacks are cast together;

wherein said first and second rotor laminations have a ring shape with an inner diameter and an outer diameter;

wherein said first and second rotor laminations have substantially the same outer diameter; and

wherein said second rotor lamination has a substantially larger inner diameter than said first rotor laminations.

11. The rotor assembly of claim 10, further comprising:

a third lamination stack attached onto said second end of said second lamination stack, wherein said third lamination stack is comprised of third rotor laminations, wherein said third lamination stack has a first end and a second end;

wherein said third lamination stack is cast together with said first and second lamination stacks;

wherein said third rotor laminations have a ring shape with an inner diameter and an outer diameter;

wherein said third rotor laminations have substantially the same outer diameter as the first and second rotor laminations; and

wherein said second rotor lamination has a substantially larger inner diameter than either of said first and third rotor laminations.

12. The rotor assembly of claim 11, wherein slots extend along periphery of outer circumference of said ring shape of said first, second and third rotor laminations.

13. A method of rotor assembly without a hub comprising:

stacking at least one plurality of annular laminations to form a first lamination stack having an inner diameter of substantially one predetermined size; and

stacking another plurality of annular laminations onto said first lamination stack to form a second lamination stack having an inner diameter of substantially another predetermined size to facilitate the attachment of the rotor assembly without a hub.

14. The method of claim 13 including stacking another plurality of annular laminations onto said second lamination stack to form a third lamination stack having an inner diameter of said one predetermined size.

15. The method of claim 14 including placing said first and second and third lamination stacks into a casting mold;

and compressing said lamination stacks sufficiently to lock all laminations together and provide a solid core assembly.