Robert A Lucas

US Patent:

43889646, Jun 21, 1983

Filed:

Oct 11, 1979

Appl. No.:

6/083972

Inventors:

David W. Almgren - Concord MA
John T. Bartoszek - Bolton MA
Robert M. Lucas - Melrose MA
Richard P. Berthiaume - Winchester MA
Richard H. Spencer - Winchester MA
William H. Saia - Danvers MA

Assignee:

Arthur D. Little, Inc. - Cambridge MA

International Classification:

G05D 2300

US Classification:

165 32

Abstract:

In a space shuttle, payloads are individually temperature controlled by means of a liquid control loop in heat exchange relationship with both the payload and a radiator or shuttle cold plate. The liquid pump is driven at a variable speed to control the heat transferred between the load and the radiator or cold plate, and the motor may be reversed to by-pass the radiator through check valves. The radiator includes heat pipes seated in elongated, high thermal conductivity extrusions and retained therein by elongated springs. The motor is a brushless DC motor isolated from the pump by a magnetic clutch and thermal isolator. The motor is driven by a digital circuit which provides a single pulse to each set of windings during each energizing time frame. The width of that pulse is modulated to provide for speed control. Pulse width modulation is by means of a one-shot, the pulse duration of which is controlled by a speed control signal.

US Patent:

52560422, Oct 26, 1993

Filed:

Feb 20, 1992

Appl. No.:

7/837979

Inventors:

John E. McCullough - Carlisle MA
Ronald J. Forni - Lexington MA
Robert M. Lucas - Lynnfield MA

Assignee:

Arthur D. Little, Inc. - Cambridge MA

International Classification:

F01C 104
F01C 2104

US Classification:

418 1

Abstract:

A bearing and lubrication system for a sealed, integrated motor driven co-rotating scroll refrigerant compressor includes hydrostatic bearings and an independent motor driven lubricant supply pump for supplying lubricant to the hydrostatic bearings mounting in the housing. The housing is divided into a high-pressure section that receives compressed refrigerant and a low pressure section containing the involute scroll compressor wraps. Individual lubricant supply sumps are provided in the high and lower pressure housing sections for supplying lubricant to the compressor bearings. The lubricant pump is capable of drawing lubricant from one or both of the lubricant supply sumps. A lubricant level sensor associated with one of the low or high pressure housing sumps is provided to maintain a desired level of lubricant therein. The lubricant supply pump is controlled so that pressure is supplied to the hydrostatic bearings during compressor operation. The lubricant may be pressurized by compressed refrigerant in the high-pressure housing section for supply to the compressor bearings with or without operation of the lubricant supply pump.