COLD HEADER FOR CRYOGENIC REFRIGERATING MACHINE
A cold head for cryogenic machines comprises a displacer mounted in a working chamber of a housing. The cold head also has a high-pressure connection for supplying highly compressed refrigerant and a low-pressure connection for discharging expanded refrigerant. Also provided is a control valve arrangement for controlling the supply and discharge of refrigerant. According to the invention there is a bypass channel connecting the high-pressure connection to the low-pressure connection.
1 . Cold head for cryogenic refrigeration machines, comprising
a displacer mounted in a working chamber of a housing,
a high-pressure connection for supplying highly compressed refrigerant into the working chamber,
a low-pressure connection for discharging expanded refrigerant from the working chamber, and
a control valve device for controlling the supply and discharge of refrigerant into and from the working chamber,
wherein
a bypass channel connecting the high-pressure connection to the low-pressure connection.
2 . Cold head for cryogenic refrigeration machines of claim 1 , wherein a throughflow regulation device is arranged in the bypass channel.
3 . Cold head for cryogenic refrigeration machines of claim 2 , wherein the throughflow regulation device is adjustable in particular during operation.
4 . Cold head for cryogenic refrigeration machines of claim 1 , further comprising a movement device for moving the displacer.
5 . Cold head for cryogenic refrigeration machines of claim 4 , wherein the movement device is configured as a piston-cylinder unit which, for actuation, is connected to the high-pressure connection and the low-pressure connection.
6 . Cold head for cryogenic refrigeration machines of claim 4 , wherein the movement device has a motor.
7 . Cold head for cryogenic refrigeration machines of claim 14 , wherein the electric motor drives an eccentric that acts on a slotted guide to cause a linear movement of the displacer.
8 . Cold head for cryogenic refrigeration machines of claim 1 , wherein the control valve device has a cyclically operating, multi-channel control valve that controls the connection of a working chamber to a high-pressure connection and to a low-pressure connection.
9 . Cold head for cryogenic refrigeration machines of claim 8 , wherein the control valve controls the connection of the piston-cylinder unit.
10 . Cold head for cryogenic refrigeration machines of claim 1 , further comprising a distributor body in which at least a first connecting channel is provided for connecting the high-pressure connection to the working chamber.
11 . Cold head for cryogenic refrigeration machines of claim 10 , wherein the first connecting channel is arranged between the control valve and the working chamber.
12 . Cold head for cryogenic refrigeration machines of claim 8 , wherein the distributor body has a second connecting channel between the control valve and the low-pressure connection.
13 . Cold head for cryogenic refrigeration machines of claim 10 , wherein the distributor body has a control channel for supplying and/or discharging a control medium, in particular a refrigerant, to and/or from the piston-cylinder unit.
14 . Cold head for cryogenic refrigeration machines of claim 6 , wherein the motor is an electric motor.