Structure of linear compressor

A linear compressor comprising:

• a hermetic casing;
• a block having formed therein a cylinder within which a piston oscillates to change a volume of a compression chamber;
• a linear motor including a stator and a rotor, the rotor being connected to the piston to move the piston within the cylinder in a first direction;
• an elastic unit which is connected at a first portion to said block and at a second portion to the piston to urge the piston in a second direction opposite the first direction in response to the movement of the piston through said linear motor so that the piston oscillates in the cylinder;
• a pressure chamber formed in said block;
• a stator moving member having disposed thereon the stator of said linear motor, said stator moving member being mounted within said pressure chamber slidably in the first and second directions;
• first and second back pressure chambers defined in said pressure chamber on both sides of the stator moving member;
• and
• a pressure controlling mechanism controlling a difference in pressure between said first and second back pressure chambers to shift said stator moving member, thereby moving the stator to a desired position.