A concentric rotary fluid machine includes a first body and a second body that are rotatable relative to each other and coaxially arranged one inside the other. A plurality of gates are supported by the second body in gate pockets. Each gate pocket includes: a gate retention recess that receives a gate cylinder of a gate; a gate seal recess that receives a sealing portion of a gate; and an intervening land. The sealing portion is configured to reciprocate up and down within a corresponding gate seal recess while maintaining contact with the recess and the second body. A plurality of lobes on the first body cause the gates to swing about respective swing axes as the first body rotates relative to the second body. The lobes and the lands are configured so that a lobe forms a substantial seal against a land when in mutual radial alignment.

A variable displacement pump can include a rotor having a plurality of vanes, and a cam ring surrounding the rotor and vanes. The vanes can be configured to extend from the rotor and contact an inner cam surface of the cam ring. The pump can also include one or more radial actuators configured to apply a radial force to the cam ring to control a position of the cam ring and the pumping action.

A production apparatus for a liquid containing gas bubbles includes a casing, a pump unit, and a gas bubble-mixing unit. The casing is provided with a main flow channel for a liquid, the main flow channel having a liquid inflow port and a liquid outflow port. The pump unit is disposed in the main flow channel and pumps the liquid to the liquid outflow port from the liquid inflow port. The gas bubble-mixing unit includes a first choke portion that is disposed in the main flow channel and has an inner diameter decreased and a gas supply channel that supplies the first choke portion with a gas.

A production apparatus for a liquid containing gas bubbles includes a casing, a pump unit, and a gas bubble-mixing unit. The casing is provided with a main flow channel for a liquid, the main flow channel having a liquid inflow port and a liquid outflow port. The pump unit is disposed in the main flow channel and pumps the liquid to the liquid outflow port from the liquid inflow port. The gas bubble-mixing unit includes a first choke portion that is disposed in the main flow channel and has an inner diameter decreased and a gas supply channel that supplies the first choke portion with a gas.

Disclosed is a pump having adjustable conveying volumes, in particular a vane, roller-cell or pendulum-slide pump, comprising a rotation assembly, a lifting ring and a rotationally driven rotor with extendable and retractable vanes, rollers or pendulum sliders that are guided in slots.

Disclosed is a pump having adjustable conveying volumes, in particular a vane, roller-cell or pendulum-slide pump, comprising a rotation assembly, a lifting ring and a rotationally driven rotor with extendable and retractable vanes, rollers or pendulum sliders that are guided in slots.

In many fields, such as manufacturing and mining, compressed air is used as a power source for industrial equipment, hand power tools, etc. Extensive compressed air systems are installed in these environments to supply compressed air where it is needed. In mining, extensive belts are frequently used to move mined material. Idler rollers are located intermittently along these belts. Embodiments of the present invention include compressors located within these idler rollers. As the belt moves and causes the roller to turn, a compressor within the roller generates compressed air. Because the belt moves nearly continuously, but the compressed air may not be consumed continuously, the air will be vented periodically. Embodiments of the present invention use these vents to clean the filters for the system. Also, some embodiments of the compressor may be produced using a laminated, or stacked, method.

An apparatus for compressing or pumping fluid includes a housing having an interior chamber. A rotating cam is rotatably mounted within an interior chamber and includes a reversible cam body configured to enable fluid to flow in a foreword direction and a reverse direction. The reversible cam body has a first sloped annular channel formed therein. The first end of the reversible cam body includes a ramp up portion, a ramp down portion, and inner and outer circumferential sidewalls that circumscribe the ramp to define the first sloped annular channel. The apparatus may include a circumferential cam gear located on the outer circumferential sidewall and a secondary drive shaft with a pinion gear to rotate the circumferential cam gear.

An apparatus for driving fluid includes a housing having an interior chamber in communication with a fluid inlet for receiving the fluid and a fluid outlet for expelling the fluid, a cam rotatably mounted within the interior chamber, the cam configured to drive fluid to flow, the cam having an annular channel formed therein, a working vane extending into the annular channel for sliding therein as the cam rotates, wherein the working vane divides the annular channel into an inlet chamber and an outlet chamber such that, as the cam rotates, the inlet chamber expands and the outlet chamber contracts, a follower vane extending into the annular channel for sliding therein as the cam rotates, wherein the follower vane allows fluid to pass in he annular channel, and a rocker arm for providing dependent motion between the working vane and the follower vane.

An electric compressor and a refrigeration device having the same are provided. The electric compressor includes: an electric motor having a stator and a rotor; a compressing mechanism having an eccentric shaft rotatably and slidably connected to the rotor and defining a compressing chamber therein, the compressing chamber being configured to perform a compression by the eccentric shaft; and a torque damping device configured to connect the rotor with the eccentric shaft, in which during the compression of the compressing chamber, a difference between a rotation angle of the eccentric shaft and a rotation angle of the rotor is a phase angle which is increased and decreased.