Sumitomo Heavy Industries, Ltd.

Changheng Liu

Qian Bao

A cryocooler includes a compressor, an expander that includes a motor and is driven by the motor, an inverter that controls an operation frequency of the motor, a high pressure line that connects the compressor to the expander such that a working gas is supplied from the compressor to the expander, a low pressure line that connects the compressor to the expander such that a working gas is collected from the expander to the compressor, a pressure measurement unit that is configured to measure pressures of the high pressure line and the low pressure line or to measure a differential pressure between the high pressure line and the low pressure line, and a controller that compares the differential pressure to a target pressure and controls the inverter such that the operation frequency of the motor is increased when the differential pressure exceeds the target pressure.

Cryocooler and control method of cryocooler

A cryocooler includes a displacer, a cylinder that forms an expansion space, a Scotch yoke mechanism configured to drive the displacer in a reciprocating manner, a first rod that extends from the Scotch yoke mechanism, a housing that includes an assist chamber, a rotary valve configured to switch between a state in which the expansion space and a discharge side of a compressor are connected and the assist chamber and a suction side of the compressor are connected and a state in which the expansion space and the suction side of the compressor are connected and the assist chamber and the discharge side of the compressor are connected, a motor configured to drive the Scotch yoke mechanism and the rotary valve, and an on-off valve configured to open and close a gas flow path through which the rotary valve and the assist chamber are connected.

Growing community of inventors

Nishitokyo, Japan

Changheng Liu