Rotor assembly for motor

Patent metadata

Field	Value
Publication number	US-10920783-B2
Application number	US-201816185887-A
Country	US
Kind code	B2
Filing date	Nov 9, 2018
Priority date	Mar 15, 2018
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

A rotor assembly for a motor includes a rotor shaft having a journal portion formed in an axial direction and having a predetermined radius about an axis, and a center shaft portion extending along the axial direction from the journal portion and having a radius smaller than a radius of the journal portion about the axis; a cylindrical, integral permanent magnet inserted into the center shaft portion to surround an outer circumferential surface of the center shaft portion and being supported by the journal portion; and a sleeve inserted into the rotor shaft to surround an outer circumferential surface of the journal portion and an outer circumferential surface of the integral permanent magnet, supporting the integral permanent magnet in the axial direction, and supporting the outer circumferential surface of the center shaft portion in the radial direction.

First claim

What is claimed is:

1. A rotor assembly for a motor, the rotor assembly comprising:
a rotor shaft including a journal portion formed in an axial direction of the rotor shaft and having a predetermined radius about an axis, and a center shaft portion extending along the axial direction from the journal portion and having a radius smaller than a radius of the journal portion about the axis;
a cylindrical, integral permanent magnet inserted into the center shaft portion to surround an outer circumferential surface of the center shaft portion and being supported by the journal portion; and
a sleeve inserted into the rotor shaft to surround an outer circumferential surface of the journal portion and an outer circumferential surface of the integral permanent magnet, supporting the integral permanent magnet in the axial direction, and supporting the outer circumferential surface of the center shaft portion in the radial direction.

2. The rotor assembly of claim 1 , wherein:
the rotor shaft is integrally formed with the journal portion and further includes a rib portion protruding in the radial direction from a rear side end of the journal portion.

3. The rotor assembly of claim 1 , wherein the sleeve includes:
a first portion supporting the outer circumferential surface of the permanent magnet in the radial direction and supporting the outer circumferential surface of the journal portion in the axial direction; and
a second portion integrally provided with the first portion and having an inner circumferential surface integrally formed with the support portion.

4. The rotor assembly of claim 3 , wherein:
an outer circumferential surface of the first portion is provided as a first bearing working surface supporting a rear side journal bearing, and
an outer circumferential surface of the second portion is provided as a second bearing working surface supporting a front side journal bearing.

5. The rotor assembly of claim 3 , wherein:
a thickness of the second portion is larger than a thickness of the first portion.

6. The rotor assembly of claim 1 , wherein:
a support portion of the sleeve protrudes from the inner circumferential surface of the sleeve toward a central side of the center shaft portion and supports the outer circumferential surface of the center shaft portion and a front side end of the permanent magnet in the axial direction.

7. The rotor assembly of claim 1 , wherein:
the journal portion has a magnet support end supporting a rear side end of the permanent magnet, and
the magnet support end has a positioning protrusion positioning a home position of the permanent magnet.

8. The rotor assembly of claim 7 , wherein:
a positioning recess coupled with the positioning protrusion is provided at the rear side end of the permanent magnet.

9. The rotor assembly of claim 1 , wherein:
an impeller of an air compressor is coupled to a front side end of the center shaft portion.

10. The rotor assembly of claim 9 , wherein:
the journal portion has a sleeve support end supporting one side end of the sleeve in the axial direction, and
an impeller support end supporting the impeller in the axial direction is provided at a front side end of the sleeve.

11. A rotor assembly for a motor, including a rotor shaft, a permanent magnet disposed on the rotor shaft along an axial direction, and a sleeve coupled to the rotor shaft in the axial direction to surround an outer circumferential surface of the permanent magnet, wherein the rotor shaft includes:
a first shaft including a first journal portion provided in the axial direction and having a predetermined radius about an axis; and
a second shaft including a second journal portion integrally formed with a center shaft portion and having a predetermined radius about the axis and the center shaft portion having a radius smaller than a radius of the first journal portion, the second shaft being coupled with the first journal portion through the center shaft portion,
wherein the center shaft portion extends from both ends of the second journal portion in the axial direction.

12. The rotor assembly of claim 11 , wherein:
the permanent magnet is configured to have an integral cylindrical shape and fitted into the center shaft portion of the second shaft on the rear side, and
a rear side end of the permanent magnet is supported by the first journal portion in the axial direction, and a front side end of the permanent magnet is supported by the second journal portion in the axial direction.

13. The rotor assembly of claim 11 , wherein the first shaft further includes:
a rib portion integrally formed with the first journal portion and protruding from the first journal portion in a radial direction.

14. The rotor assembly of claim 11 , wherein:
a coupling recess coupled with the center shaft portion of the second shaft on the rear side is provided in the first journal portion.

15. The rotor assembly of claim 11 , wherein:
an outer circumferential surface of the first journal portion coupled with a rear side of the sleeve is provided as a first bearing working surface supporting a rear side journal bearing, and
an outer circumferential surface of the sleeve on a front side is provided as a second bearing working surface supporting a front side journal bearing.

16. The rotor assembly of claim 11 , wherein:
the first journal portion has a magnet support end supporting a rear side end of the permanent magnet, and
the magnet support end has a positioning protrusion positioning a home position of the permanent magnet.

17. The rotor assembly of claim 16 , wherein:
a positioning recess coupled with the positioning protrusion is provided at the rear side end of the permanent magnet.

18. The rotor assembly of claim 11 , wherein:
an impeller of an air compressor is coupled to a front side end of the center shaft portion formed on a front side of the second shaft in the axial direction.

19. The rotor assembly of claim 18 , wherein:
the first journal portion has a sleeve support end supporting a rear side end of the sleeve in the axial direction.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Lee Chang Ha
• Kim Hyunyoo

Classifications

• Y02T90/40

  Application of hydrogen technology to transportation, e.g. using fuel cells · CPC title

• Y02E60/50

  Fuel cells · CPC title

• H02K7/14

  Structural association with mechanical loads, e.g. with hand-held machine tools or fans (with fan or impeller for cooling the machine H02K9/06) · CPC title

• H02K7/003

  Couplings; Details of shafts (means for mounting rotors on shafts H02K1/28) · CPC title

• H02K5/163

  radially supporting the rotary shaft at only one end of the rotor (H02K5/165, H02K5/167, H02K5/173 take precedence) · CPC title