MINIATURE HIGH SPEED COMPRESSOR HAVING EMBEDDED PERMANENT MAGNET MOTOR

• US 20070269323A1
• Filed: 05/22/2007
• Published: 11/22/2007
• Est. Priority Date: 05/22/2006
• Status: Active Grant

• Current Assignee: Dipjyoti Acharya, Jayanta S. Kapat, Krishna M. Kota, Lei Zhou, Liping Zheng, Louis Chow, Thomas X. Wu, Xiaoyi Li
• Original Assignee: Dipjyoti Acharya, Jayanta S. Kapat, Krishna M. Kota, Lei Zhou, Liping Zheng, Louis Chow, Thomas X. Wu, Xiaoyi Li
• Inventors: Zheng, Liping, Zhou, Lei, Chow, Louis, Wu, Thomas X., Kapat, Jayanta S., Li, Xiaoyi, Kota, Krishna M., Acharya, Dipjyoti
• Granted Patent: US 7,942,646 B2
• Time in Patent Office: Days
• US Class Current: 417/423.700
• CPC Class Codes: F04D 25/06 the pump being electrically driven F04D25/08 takes precedence
• CPC Class Codes: F04D 25/082 the unit having provision for cooling the motor
• CPC Class Codes: F04D 27/0261 by varying driving speed
• CPC Class Codes: F04D 29/059 Roller bearings
• CPC Class Codes: F04D 29/441 especially adapted for elastic fluid pumps
• CPC Class Codes: F04D 29/5806 Cooling the drive system
• CPC Class Codes: F04D 29/584 cooling or heating the machine F04D29/5846, F04D29/5853 take precedence
• CPC Class Codes: F04D 29/622 Adjusting the clearances between rotary and stationary parts
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

A high speed centrifugal compressor for compressing fluids includes a permanent magnet synchronous motor (PMSM) having a hollow shaft, the being supported on its ends by ball bearing comprising supports. A permanent magnet core is embedded inside the shaft. A stator with a winding is located radially outward of the shaft. The PMSM includes a rotor including at least one impeller secured to the shaft or integrated with the shaft as a single piece. The rotor is a high rigidity rotor providing a bending mode speed of at least 100,000 RPM which advantageously permits implementation of relatively low-cost ball bearing comprising supports.

Claims

1. A high speed centrifugal compressor for compressing fluids, comprising:

a permanent magnet synchronous motor (PMSM) comprising;

a hollow shaft, said shaft being supported on its ends by ball bearing comprising supports,

a permanent magnet core embedded inside said shaft, and

a stator with a winding located radially outward of said shaft, said PMSM including a rotor comprising at least one impeller secured to said shaft or integrated with said shaft as a single piece, wherein said rotor is a high rigidity rotor, said rotor providing a bending mode speed of at least 100,000 RPM.

2. The compressor of claim 1, further comprising a housing enclosing said PMSM, said housing including an axially extending gas inlet and a gas outlet passage, wherein passageways are created between said PMSM and said housing to convey said fluid from said inlet to said outlet.

3. The compressor of claim 1, wherein said gas inlet and gas outlet are disposed in a straight line.

4. The compressor of claim 1, wherein said shaft includes a diameter reduction on both of its ends.

5. The compressor of claim 1, wherein said stator is a slotless stator.

6. The compressor of claim 1, wherein said stator is a slotted stator.

7. The compressor of claim 1, wherein said ball bearing comprising supports comprise a plurality of ceramic ball bearings.

8. The compressor of claim 7, wherein said ball bearings are contained in a enclosure sealed and isolated from said fluid.

9. The compressor of claim 1, wherein said winding comprises a multi-strand Litz wire winding.

10. The compressor of claim 1, wherein said rotor comprises a two pole rotor.

11. The compressor of claim 1, wherein said winding and said stator are integrated with an axial diffuser.

12. The compressor of claim 1, wherein said axial diffuser includes a bend-over section, said impeller being radially extended followed by said axial diffuser with said bend-over section.