The compressor presents a first and a second cylinder block arranged in V and defining, respectively, a first and a second cylinder, and being affixed on a base block, each cylinder housing a respective piston driven by a crankshaft which is housed and supported on the base block. The first and the second cylinder block incorporate, respectively, a first and a second duct portion having an outer end open to the interior of the cylinder head of the respective cylinder, and an inner end open to a third duct portion incorporated to the base block, said duct portions forming a compressed air duct connecting the first cylinder to the second cylinder.

A variable-pressure air pump includes a first cylinder with a first chamber and a second cylinder with a second chamber movably connected with one another. The second chamber fluidly communicable with the outside of the variable-pressure air pump selectively. A discharge device includes a connecting member and a switch movably connected with one another. The connecting member defines at least one discharge hole fluidly connecting with the second chamber. The switch has at least one flow guide portion and at least one blocking portion. The switch is movable between a first position in which the at least one flow guide portion is adjacent and opens to the at least one discharge hole and a second position in which the at least one blocking portion is adjacent to and blocks the at least one discharge hole.

A displacement pump has multiple gas compression stages and serial gas flow through the compression stages. The gas is initially compressed in a first compression stage by a first fluid displacement member. The gas from the first compression stage flows to a second compression stage. The gas in the second compression stage is compressed by a second fluid displacement member and output from the pump.

Disclosed are a variable capacity compressor operation mode determination method and device, a variable capacity compressor and an air conditioner. The variable capacity compressor operation mode determination method includes: detecting a current value of a compressor at present as A1 before switching an operation mode of the compressor; detecting the current value of the compressor at present as A2 after switching the operation mode of the compressor and reaching a preset time; comparing A1 and A2, determining that the switching of the operation mode of the compressor is successful when a ratio relationship between A1 and A2 satisfies a preset condition, and determining that switching of the operation mode of the compressor is failed when the ratio relationship between A1 and A2 dissatisfies a preset condition.

A variable-pressure air pump includes a first cylinder with a first chamber and a second cylinder with a second chamber movably connected with one another. The second chamber fluidly communicable with the outside of the variable-pressure air pump selectively. A discharge device includes a connecting member and a switch movably connected with one another. The connecting member defines at least one discharge hole fluidly connecting with the second chamber. The switch has at least one flow guide portion and at least one blocking portion. The switch is movable between a first position in which the at least one flow guide portion is adjacent and opens to the at least one discharge hole and a second position in which the at least one blocking portion is adjacent to and blocks the at least one discharge hole.

Disclosed are a variable capacity compressor operation mode determination method and device, a variable capacity compressor and an air conditioner. The variable capacity compressor operation mode determination method includes: detecting a current value of a compressor at present as A1 before switching an operation mode of the compressor; detecting the current value of the compressor at present as A2 after switching the operation mode of the compressor and reaching a preset time; comparing A1 and A2, determining that the switching of the operation mode of the compressor is successful when a ratio relationship between A1 and A2 satisfies a preset condition, and determining that switching of the operation mode of the compressor is failed when the ratio relationship between A1 and A2 dissatisfies a preset condition.

The invention relates to a method for operating a piston compressor (100) having a reciprocating piston (111) in a cylinder (110), wherein an inlet valve (112) and an outlet valve (113) are provided in the cylinder (110) on the side of a medium (b) which is to be compressed and conveyed, wherein the reciprocating piston (111) is moved to and fro by way of a hydraulic drive (120, 121) with a hydraulic piston (120) with the use of a hydraulic medium (a) in a first volume (141), with which the reciprocating piston (111) is loaded on the side of the hydraulic drive (120, 121), wherein, if required, hydraulic medium (a) is fed into the first volume (141) and/or is discharged from the first volume (141) in a manner which is dependent on a position of the hydraulic piston (120) and/or a rotational angle ((p) of a shaft (121) which is provided for moving the hydraulic piston (120) in relation to a position (x) of the reciprocating piston (120) and/or a pressure (p) in the first volume (141), and to a piston compressor (100) of this type.

An air compressor includes: a motor; a compression mechanism that is driven by the motor and that is configured to generate compressed air; a tank that is configured to store the generated compressed air; a load acquisition part that is configured to acquire a load applied to the compression mechanism; and a control part that is configured to control a rotation of the motor. The control part is configured to perform control for changing a TN characteristic of the motor in response to the load of the compression mechanism acquired by the load acquisition part.

A membrane heat exchanger comprising a first planar sheet a second planar sheet coupled to the first planar sheet at least by a seam and at least one fluid chamber defined by the first and second planer sheet and the seam and comprising a first and second end, the fluidic chamber extending a length of the membrane heat exchanger.

A two-stage compressor of a compressed air supply device includes a low pressure stage having a low pressure cylinder, a high pressure stage having a high pressure cylinder, a low pressure piston guided in an axially movable manner in the low pressure cylinder, a high pressure piston guided in an axially movable manner in the high pressure cylinder, a piston rod rigidly connecting the low pressure piston and the high pressure piston, and a sliding block guide. The sliding block guide includes a recess arranged in the piston rod and further includes two substantially parallel sliding block tracks. One of the sliding block tracks has an arc-shaped indentation in a central portion. The sliding block tracks are constructed and such that a movement of the low pressure piston and of the high pressure piston follows a piston stroke curve that deviates from a regular sinusoidal stroke curve.