The present disclosure relates to a simplified roots-type blower having an improved sound signature. The roots-type blower includes a rotor bore housing having a molded, one-piece polymeric construction. The rotor bore housing defines a first rotor bore and a second rotor bore. The rotor bore housing also defines a first bearing pocket corresponding to the first rotor bore and a bearing pocket corresponding to the second rotor bore axis. The rotor bore housing further defining a timing gear chamber.

A central distribution unit (CDU) for circulating coolant is disclosed. The CDU may operate under negative pressure and can have a number of operation modes including: normal operation, pump priming, fill, drain, purge and vacuum test. The CDU includes various valves, pumps and sensors, the placement and actuation of which transitions the CDU into the various modes.

A pump with two independent motors is disclosed. The first motor is mechanically connected to a first rotor comprising a first plurality of teeth radiating from the center of the first rotor. The second motor is mechanically connected to a second rotor comprising a second plurality of teeth radiating from the center of the first rotor, wherein the first plurality meshes with the second plurality. A sealed case may house the first and second rotors, and the case may include a suction inlet and a pressure outlet. Rotating the rotors propels a liquid from the suction inlet to the pressure outlet. Because the motors are independent of each other, when one motor fails to rotate the other motor will rotate both rotors and maintain the propelling liquid from the suction inlet to the pressure outlet. The pump may be a gear pump or a rotary lobe pump.

The invention relates to a rotary piston pump comprising a housing with a housing interior, an inlet opening, and an outlet opening; a first rotary piston which is mounted within the housing interior in a rotational manner about a first rotational axis; and a second rotary piston which is mounted within the housing interior in a rotational manner about a second rotational axis. The first rotary piston and the second rotary piston engage into each other in a region between the first and the second axis and displace liquid. The first rotary piston has a frame assembly which comprises multiple mutually spaced plates and is at least partly filled and enveloped with a polymer material.

A roots pump comprising: a rotary shaft; a rotor having a hole-forming surface that forms an insertion hole, and a first bearing and a second bearing. Each of the first bearing and the second bearing includes an inner ring and an outer ring. The rotary shaft is press-fitted in the inner ring of the first bearing, and fitted in the inner ring of the second bearing with a clearance between the rotary shaft and the inner ring of the second bearing. An edge portion of the hole-forming surface adjacent to the first bearing serves as a press-fitting portion in which the rotary shaft is press-fitted, and at least an edge portion of the hole-forming surface adjacent to the second bearing serves as a clearance-fitting portion in which the rotary shaft is fitted with a clearance between the rotary shaft and the clearance-fitting portion.

A rotary positive displacement pump includes a main body rotationally supporting two parallel, axially extending, shafts with gears in constant mesh condition, such that the shafts rotate in opposite directions. A rotor case body is connected to a front side of the main body and has a stationary interior pumping cavity, fluid product inlet and outlet openings, and two cylindrical rotor case hubs each receiving internally one of the shafts. A pair of rotors each have a rotor wing and a rotor drive element that is mounted torque proof on a rotor seat at an end region of one of the shafts. Each rotor seat pair has an axial abutment surface and a mounting surface. The pump also includes fasteners each engaging a mating section of one of the shafts and exerting an axial clamping force on one of the rotor drive elements against one of the axial abutment surfaces.

A pump for dispensing semi-liquid food products, which comprises an inlet opening, an outlet opening, a dispensing path between the inlet opening and the outlet opening, a rotor for pushing the product along the dispensing path, and an airtight chamber, which is interposed between the inlet and outlet openings and coaxially contains the rotor; the dispensing path is defined by the cyclically choked gap formed between the outer periphery of the rotor, equipped with three projecting and angularly equidistant lobes and the inner periphery of the chamber, which is elastically deformable.

A vacuum system has a condenser and a root vacuum pump set, wherein the condenser is an independent inlet condenser set connected to a generator including an air cooling power generator condenser. A pressure sensor is installed on the independent inlet condenser set for detecting a first input pressure. Air outputted from the independent inlet condenser set is compressed by the root vacuum pump set. A backing pump receives an air outputted from the root vacuum pump set through an output pipe. A bypass pipe is connected between an output end of the root vacuum pump set and a vapor-liquid separator connected to the backing pump. A central controller serves to receive the first input pressure and determine to control the air from the root vacuum pump set to be outputted to the output pipe or the bypass pipe by a control valve.

A rotary, self-priming, positive displacement pump is described. The pump may include a pump housing including an inlet and an outlet, a pump chamber including an upper wall, a lateral wall, and a floor, first and second rotary impellers in the pump chamber, and a pair of gears each secured to the first and second rotary impellers, and a pressure relief feature operable to relieve pressure developing in a relatively high pressure zone of the pump chamber. The gears mesh with each other to ensure that the vanes do not contact one another during rotation. The pressure relief feature may comprise one or more channels formed in the pump housing and/or the first and second rotary impellers. The channels connect the high pressure zone with another zone to redistribute pressure. The channels may include one continuous channel or alternatively, a plurality of unconnected channels.

A rotary, self-priming, positive displacement pump is described. The pump may include a pump housing having a fluid inlet and outlet, first and second rotary impellers having vanes, an input shaft and drive gears synchronizing the impellers to avoid clash, and a dividing wall separating a pumping chamber from a chamber containing the drive gears. The dividing wall separates the pumping chamber from the gear chamber, partially supports impeller shafts, and is formed in a plurality of abutting manually separable sections. When manually pulled apart, the separable sections free the impeller shafts for manual removal, to facilitate manual service to the pump.