Piston-reciprocating gas compressor

Abstract

A drive shaft is driven by an electric motor in a motor casing. A crankshaft integrally connected with the drive shaft is provided in a crankcase. A piston is reciprocated by the crankshaft in a cylinder. A gas is introduced from the outside into the motor casing and forwarded into the crankcase. The gas is further guided into a space on the piston through a gas-guiding groove formed in the inner circumference of the cylinder. The piston moves up to compress the gas in the space while the piston closes the upper end of the gas-guiding groove, so that the gas is discharged to the outside.

1 . A piston-reciprocating gas compressor comprising: 
 an electric motor;    a motor casing including the electric motor and having a gas-introducing hole through which a gas is introduced from an outside:    a drive shaft driven by the electric motor and extending in the motor casing;    a crankshaft integrally connected to the drive shaft;    a crankcase including the crankshaft and having a gas-guiding hole to allow the motor casing to communicate with the crankcase;    a piston reciprocated by the crankshaft; and    a cylinder including the piston and having a gas-guiding groove in a lower part of an inner circumference to allow the crankcase to communicate with a space on the piston in the cylinder when the piston is in a lower position so that the gas in the crankcase is guided into the space through the gas-guiding groove between an outer circumference of the piston and the inner circumference of the cylinder, an upper end of the gas-guiding groove being closed when the piston moves up so that the gas in the space on the piston is compressed and discharged from the cylinder.    
   
   
       2 . The piston-reciprocating gas compressor according to  claim 1  wherein the gas is discharged through a discharge check valve in a wall of the cylinder.