Conference Year

2014

Keywords

novel rotary compressor, suction, discharge

Abstract

A parts of the contemporary rotary compressors are supported as by revolving crankshaft (rotor, roller, etc.), so by the housing (stator, pump, suction accumulator, etc.). Such dual supporting structure complicates assembly of a compressor due to the necessity of precision axial and radial positioning of the pump parts, motor rotor and stator. Developed novel rotary compressor provides a unitary assembly, in which a rotor of the driver -external rotor electric motor, is integrated with concentrically situated pump and rotatably arranged on stationary crankshaft. Stationary crankshaft is fixedly connected to the hermetic housing and supports as the fixed to it motor stator, so the rotor block and the piston block revolving around it. The single structure supporting the motor stator, the rotor block, the piston block and housing simplifies compressor assembly, and allows precision, reliable setting of the parts due to the common single reference - axial line. The piston block and the rotor block have only one line rolling contact, where tangential velocities of blocks are unidirectional and equal in magnitude. It means that the sliding frictional losses at the line contact are minimal. The frictional losses between the rotor blocks radial surfaces and facing surfaces of the piston block heads are also minimal due to the low relative rubbing speed between synchronously revolving in one direction contacting surfaces. Suction system of the novel rotary compressor excluded direct delivery of the refrigerant to the suction chamber by positioning a suction input cavity and a motor cavity in between the suction intake located at the top of the housing and suction port inlet at the top of the motor cavity. The arrangement of a refrigerant delivery eliminates external accumulator, increases the liquid refrigerant storage capacity and provides cooling of the compressor motor during and after its duty cycle. The vapor will be delivered substantially free of liquid refrigerant into the suction chamber under higher pressure (supercharged) due to the action of the impeller positioned in the motor cavity. The rotation of the piston block is due to the distributed forces which have been transmitted from an external rotor of the motor through the direct, no sliding line contact between both blocks and through a mechanical link – vane, which is rigidly fixed in the piston block wall. Another advantage of the novel rotary compressor is that the discharge gas will be tangentially ejected in form of one or more high-speed jets in the direction opposite to the direction of rotation. It creates a reaction forces acting in the direction of rotation and added to the forces revolving the piston block. The design modifications described above, employment of an external rotor motor as a driver, elimination of the roller, reciprocating movement of the vane, vane spring, and external accumulator, utilization of new developed tubular discharge valve improve performance of novel rotary compressor, make it compact, (smaller package space), reliable, and reduce manufacturing cost . *) Dreiman N.I., 2013a, “Rotary compressor with the stationary crankshaft” US Patent pending.

1226_presentation.pdf (1088 kB)
Rotary Compressor with the Stationary Crankshaft

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