Double acting refrigeration compressor

A double-acting refrigerant compressor for refrigerant recovery comprising:

• a refrigerant to be recovered;
• a piston of the double-acting refrigerant compressor having a first piston portion of a first outer diameter and a second piston portion of a second outer diameter;
• two cylinder portions of said double-acting refrigerant compressor, said two cylinder portions having different cylinder inner diameters including a first cylinder portion having a first cylinder portion inner diameter and a second cylinder portion having a second cylinder portion inner diameter, said two cylinder portions arranged opposite to each other and being immobile relative to each other, said first outer diameter of said first piston portion corresponding to said first cylinder portion inner diameter and said second outer diameter of said second piston portion corresponding to said second cylinder portion, said piston freely guided within said two cylinder portions without a connection to a piston rod;
• an inlet valve of said double-acting refrigerant compressor, said inlet valve disposed at an inlet plate of the first cylinder portion of said two cylinder portions;
• an outlet valve of said double-acting refrigerant compressor, said outlet valve disposed at an outlet plate of the second cylinder portion of said two cylinder portions, said second cylinder portion inner diameter being smaller than said first cylinder portion inner diameter;
• a flow channel of said double-acting refrigerant compressor, said flow channel extending internally through said piston;
• a flow channel back-check valve of said double-acting refrigerant compressor, said flow channel back-check valve disposed in said flow channel, said flow channel back-check valve to cause a unidirectional flow direction of said refrigerant to be recovered;
• wherein the cylinder portions are spaced from each other in such a manner that a region of the piston is mechanically accessible through a space formed between the spaced cylinder portions from outside the cylinder portions during operation of said double-acting refrigerant compressor;
• wherein the piston on an end side thereof comprises a low-pressure compression face and on an opposite side comprises a high-pressure compression face which is smaller than the low-pressure compression face;
• and
• wherein the piston comprises, between the low-pressure compression face and the high-pressure compression face, an auxiliary compression surface which, together with the cylinder portion forming the low-pressure working volume, forms an auxiliary volume to generate a restoring force acting against the driving force of the piston, thereby assisting in controlling the piston, said auxiliary volume disposed axially between said inlet valve plate for a low pressure working volume and said space, and said space disposed axially between said auxiliary volume and said outlet valve plate of a high pressure working volume.

A double-acting refrigerant compressor comprising a piston freely guided on two cylinder portions of different inner diameters arranged opposite to each other and being immobile relative to each other, said piston guided in said two cylinder portions and driven without a connection to a piston rod, said piston comprising a flow channel extending internally through the piston and each cylinder portion, the flow channel of the piston comprising, respectively, at least one back-check valve, the at least one back-check valve being arranged with a unidirectional flow;

• and wherein the cylinder portions are part of a cylinder which is divided into said two cylinder portions being mutually spaced from each other such that the cylinder has an opening in its middle in such a manner that a region of the piston is directly mechanically accessible through a space formed between the spaced cylinder portions from outside the cylinder portions through the opening;
• wherein the piston on an end side thereof comprises a low-pressure compression face and on an opposite side comprises a high-pressure compression face which is smaller than the low-pressure compression face;
• and
• wherein the piston comprises, between the low-pressure compression face and the high-pressure compression face, an auxiliary compression surface which, together with the cylinder portion forming the low-pressure working volume, forms an auxiliary volume to generate a restoring force acting against the driving force of the piston, thereby assisting in controlling the piston, said auxiliary volume disposed axially between an inlet valve plate for a low pressure working volume and said space, and said space disposed axially between said auxiliary volume and an outlet valve plate of a high pressure working volume.