Patent ID: 8516833

Claim:
A 4-valve pulse tube cryocooler comprising: a first regenerator including a high-temperature end and a low-temperature end; a first pulse tube including a high-temperature end and a low temperature end connected to the low-temperature end of the first regenerator; a compressor including a high-pressure end and a low-pressure end; a first coolant supply channel, including a first high-pressure pipe that includes a first on-off valve provided thereon, and connected to the high-pressure end of the compressor and the high-temperature end of the first regenerator; a second coolant supply channel, connected to the high-pressure end of the compressor, including a second high-pressure pipe that includes a second on-off valve provided thereon, and a first common pipe that includes a first flow control valve provided thereon and connected to the high-temperature end of the first pulse tube; a first coolant recovery channel including a first low-pressure pipe that includes a third on-off valve provided thereon, and connected to the low-pressure end of the compressor and the high-temperature end of the first regenerator; a second coolant recovery channel, connected to the low-pressure end of the compressor, including a second low-pressure pipe that includes a fourth on-off valve provided thereon, and the first common pipe that includes the first flow control valve provided thereon and connected to the high-temperature end of the first pulse tube; and a third coolant recovery channel including a first end connected directly to the low-pressure end of the compressor, a second end opposite to the first end and connected to the high-temperature end of the first pulse tube via the first common pipe, and a first flow resistance member interposed between the first and second ends of the third coolant recovery channel wherein the first end of the third coolant recovery channel is connected to the low-pressure end of the compressor without passing through the third and fourth on-off valves.