Linear compressor including reciprocating piston and machined double-helix piston spring

A linear compressor, comprising:

• a housing including a cylinder that defines a compression chamber therein having a variable volume;
• a piston slidable located in the cylinder for varying said volume of the compression chamber;
• a motor connected to one end of the piston for causing the piston to reciprocate in the cylinder;
• and
• an integral double-helix spring, including:
• a first end member which is attached to the motor and supports the piston,
• a second end member fixed to the housing, and
• first and second resilient helical members which extend between the first and second end members along a longitudinal axis,
• wherein the first and second helical members have the same twist direction, are interspersed with each other along the longitudinal axis and are rotationally displaced from each other about the longitudinal axis by substantially 180.degree. from the first end member to the second end member such that lateral reaction forces thereof on the piston are mutually canceling to minimize barrel shaped piston wear and loss of compression ratio when the motor causes the piston to reciprocate against a force of the spring.

A linear compressor, comprising:

• a housing including a cylinder that defines a compression chamber therein having a variable volume;
• a piston slidable located in the cylinder for varying said volume of the compression chamber;
• a motor connected to one end of the piston for causing the piston to reciprocate in the cylinder;
• and
• an integral double-helix spring, including:
• a first end member which is attached to the motor and supports the piston,
• a second end member fixed to the housing, and
• first and second resilient helical members which extend between the first and second end members along a longitudinal axis,
• wherein the first and second helical members have opposite twist directions respectively and are connected in series and spaced from each other along said longitudinal axis such that lateral reaction forces thereof on the piston are mutually canceling to minimize barrel shaped piston wear and loss of compression ratio when the motor causes the piston to reciprocate against a force of the spring.