A double-piston compressor of a compressed air supply device includes a first pressure stage and a second pressure stage, each having a cylinder with a piston guided therein in an axially movable manner. The piston of the cylinder of the first pressure stage and the cylinder of the second pressure stage are rigidly connected to one another via a piston rod and are in driving connection with the drive shaft via a slotted guide. The slotted guide comprises a recess which is formed in the piston rod, provided with a slotted guide track and oriented perpendicularly to an axis of rotation of the drive shaft with its cross-sectional plane. The slotted guide comprises a drive roller which is engaged with the recess and fastened to the drive shaft in an axially parallel, eccentric, and also rotatable manner with respect to the axis of rotation of the drive shaft.

The inflating device has a body, a large cylinder, a small cylinder, a handle, a switching mechanism, and a switching device. The large cylinder is mounted moveably in the body and has an upper input gap, an inner bottom base, and a bottom base. The upper input gap is defined between an outer surface of a bottom end of the large cylinder and an inner surface of a first chamber of the body. The bottom base is connected with the large cylinder, is located below the inner bottom base, and has a first annular holding recess and a first O-ring. The small cylinder is mounted moveably in a second chamber of the large cylinder and has a piston base. The handle is mounted on the top end of the small cylinder. The switching mechanism is mounted on the top end of the large cylinder.

A variable pressure air pump includes a first cylinder and a second cylinder movable relative to the first cylinder along a longitudinal axis. An air tube is mounted in the first and second cylinders. A mounting portion is integrally formed on a first end of the air tube. A first piston and a second piston compress air in the first and second cylinders. A connecting device is mounted to the first cylinder for coupling with an object to be inflated. An air escape device selectively seals a second chamber of the second cylinder to selectively compress the air in the second cylinder. A first check valve is mounted to the mounting portion of the air tube. A second check valve is mounted to the second piston.

A vacuum generation system and method utilizes a dual-action piston-cylinder vacuum generation system to evacuate a vacuum storage. Saturated steam of higher than ambient pressure is inserted into a condensation cylinder with two chambers separated by a movable piston. Steam moves the piston to fill one chamber while expel gaseous content and condensate out of the other chamber. Steam is then condensed to a rough vacuum (RV) state by cooling. By repeated operations of inserting and condensing steam in each chamber alternatively, a sustained vacuum generation is achieved. A multi-level vacuum storage is also disclosed with a high vacuum (HV) storage placed inside a rough vacuum (RV) storage to reduce leakage as well as mechanical stresses. The vacuum generation system and method is extended for creating a prime mover or actuator to drive vacuum pumps maximizing thermal energy usage for increased vacuuming capacity.

A rolling cylinder displacement compressor including a minimum pressure bypass port as an opening of a minimum pressure bypass valve flow path, which is connected to a compression chamber formed in the compression portion in a lowest pressure state, of the bypass valve flow path is arranged such that a compression chamber faces an opening of the discharge flow path or the minimum pressure bypass port. The minimum pressure bypass port may be configured such that a minimum pressure port center as the center of the minimum pressure bypass port is arranged in a rotation advanced-side region with respect to an advanced radius line as a line connecting a cylinder advanced corner point of the compression chamber at the start of a compression stroke and the rotation center of the rolling cylinder.

A method of operating a reciprocating compressor for a vapour compression system is disclosed. The reciprocating compressor comprises at least two cylinders and at least two unloaders, each unloader can be operated in an idle mode or in an active mode and therefore the reciprocating compressor can run in more than two capacity states. The capacity states alternates periodically between states in such a way that a substantially continuous range of effective capacities can be obtained while the individual cylinders are evenly loaded.

The invention relates to a pumping system (1), in particular, for transporting gaseous and/or liquid media having two parallel hydraulically operated oscillating piston pumps (2, 3) whose pistons (8) are moved by means of electromagnetic fields, whereby the electromagnetic fields are generated in field coils (10, L1, L2) by means of half-wave direct current pulse. The invention distinguishes itself by a circuit arrangement (19) that can be connected to an alternating current source having two parallel electric branches that are connected to the field coils (L1, L2) of one of the oscillating pumps (2, 3) respectively, wherein the circuit arrangement (19) is equipped in such a way that the field coils (10, L1, L2) are operated electrically out of phase so that the oscillating piston pumps (2, 3) are operated with a phase displacement of 180. The invention further relates to a method for operating the pumping system electrically, and a circuit configuration for the pumping system and accordingly, for executing the method.

A natural gas compressor can include a pre-staging chamber that couples with a supply line to receive natural gas from the supply line. The compressor can additionally include a first-stage chamber that couples with the supply line to receive natural gas from the supply line. The first-stage chamber can additionally be coupled with the pre-staging chamber to receive from the pre-staging chamber natural gas that has been compressed by the pre-staging chamber. The compressor can also include a second-stage chamber configured to receive natural gas that has been compressed by the first-stage chamber.

A reciprocating-piston machine includes at least one first cylinder and at least one first piston assigned to the first cylinder as well as at least one second cylinder and at least one second piston assigned to the second cylinder. During operation, the first piston and the second piston are deflected in a respective cylinder displacement chamber of the respective first cylinder and the second cylinder. The reciprocating-piston machine further includes a crankshaft which, during operation, can be driven and which has an eccentric crankshaft journal and a drive shaft coupling designed for the coupling of a drive shaft of a drive motor for driving the crankshaft. Additionally, the reciprocating-piston machine includes a first connecting rod configured to deflect the first piston, a second connecting rod configured to deflect the second piston, and a bearing pin about which the first and second connecting rod are rotationally movable.

Most multistage compressors specify a maximum inlet pressure that may be supplied to the compressor to stay within designed limits. If the supply gas to be compressed is at a higher pressure than the specified maximum inlet pressure, then its pressure must be reduced before connecting it to the compressor. This pressure reduction is inefficient. The present invention avoids reducing the inlet pressure by routing the supply gas directly to the appropriate compression stage depending on its inlet pressure such that the compressor loads are still within the specified limits of the equipment.