US 7,377,035 B2
Refrigeration device with improved DC motor
Uri Bin-Nun, Chelmsford, Mass. (US); and Daniel L. Manitakos, Boxford, Mass. (US)
Assigned to Fursystems Inc., North Billerica, Mass. (US)
Filed on Apr. 23, 2004, as Appl. No. 10/830,630.
Prior Publication US 2005/0235686 A1, Oct. 27, 2005
Int. Cl. B23P 11/00 (2006.01); B23P 15/10 (2006.01)
U.S. Cl. 29—888.048  [92/223; 417/415] 4 Claims
OG exemplary drawing
 
1. A method for forming a gas compressor comprising the steps of:
forming a thin walled cylinder sleeve with an inside and an outside diameter; said inside diameter comprising a cylinder bore diameter;
applying a wear resistant coating having a hardness of RC 60 or more to at least the cylinder bore surface;
forming a compression piston with an outside diameter for mating with the cylinder bore, the compression piston comprising a solid cup shaped element having a solid circular disk-shaped closed end for compressing a gas and an annular cylindrical wall portion for mating with the cylinder bore along most of a longitudinal length of the cylinder bore;
applying a first layer of malleable, vibration dampening material that includes a solid lubricating compound impregnated therein over the piston outside diameter, said first layer being applied in sufficient thickness that the piston diameter is oversized compared to said cylinder bore diameter;
installing the piston into the cylinder bore by a press fit and attaching the piston to a drive mechanism for reciprocating the piston within the cylinder bore until a sufficient amount the first layer of material applied to the piston outside diameter is removed, to provide a substantially zero clearance fit between the piston outside diameter and the cylinder bore;
installing the cylinder sleeve and mating piston into a crankcase formed with a bore for receiving the cylinder sleeve therein, and bonding the cylinder sleeve outside diameter to the crankcase bore;
continuing to remove the first layer of material applied to the piston outside diameter until a substantially uniform non-zero clearance fit is provided between the piston outside diameter and the cylinder bore;
cleaning loose material from the piston and the cylinder sleeve; and,
applying a second layer comprising a hard wear resistant material onto the piston outside diameter over said first layer, said second layer being applied to a thickness consistent with restoring a substantially zero clearance fit between the piston outside diameter and the cylinder bore.