Reciprocating compressor and method for driving same

A reciprocating compressor comprising:

• a casing having an inner space communicating with a suction pipe;
• a frame provided in the inner space of the casing;
• a reciprocating motor coupled to the frame, and having a mover, the mover performing a linear reciprocating motion;
• a cylinder coupled to the frame and having a compression space;
• a piston inserted into the cylinder to perform a reciprocating motion, the piston having a suction passage formed there through in a lengthwise direction to guide a refrigerant into the compression space;
• a suction valve coupled to an end surface of the piston and configured to open and close the suction passage;
• a discharge valve provided at an end surface of the cylinder and configured to open and close the compression space;
• a discharge cover installed at an end side of the cylinder and having a discharge space accommodating the discharge valve therein, the discharge space communicating with a discharge pipe;
• a gas bearing having a plurality of gas holes penetratingly formed in the cylinder, the plurality of gas holes configured to inject therethrough a part of the refrigerant, discharged from the compression space into the discharge space, into a portion between the cylinder and the piston so as to support the piston with respect to the cylinder;
• and
• a block-preventing unit configured to prevent the gas holes of the gas bearing from being blocked due to foreign materials,
• wherein the block-preventing unit is configured as a vibration unit to vibrate the cylinder, the vibration unit including a controller to excite a number of vibrations of the reciprocating motor to a frequency higher than an operating frequency and a timer configured to vibrate the cylinder at predetermined periods, and
• wherein the block-preventing unit determines whether or not a foreign material-removing operation is required, and the controller increases a number of vibrations of the piston when the foreign material-removing operation is required to shake out foreign materials from the gas holes of the cylinder, and after the foreign material-removing operation is complete, decreases the number of vibrations of the piston to return to a normal operation.