A screw compressor for a utility vehicle has at least one female screw, at least one male screw that meshes with the female screw, and at least one screw compressor drive which drives the female screw.

A welding machine includes a welding power supply that generates a welding waveform during a welding operation, an internal combustion engine, and a generator that is operatively connected to the welding power supply to supply electrical energy to the welding power supply. The generator includes a rotor shaft driven by the internal combustion engine, and an end casting located at an end of the generator opposite the internal combustion engine. A rotary screw compressor is mounted to the end casting of the generator. A clutch mechanism couples the rotor shaft to the rotary screw compressor to selectively drive the rotary screw compressor by the rotor shaft.

Power systems and methods of controlling an engine driven air compressor include an air compressor driven by an engine via a clutch. A first pressure sensor configured to sense a pressure level at an outlet of the air compressor. An inlet valve configured to close in response to the first pressure sensor sensing a pressure level above a first pressure level. In addition, a second pressure sensor to sense a pressure level below a second pressure level at a housing of the air compressor, wherein the clutch is configured to disengage in response to the second pressure level, wherein the first pressure level is higher than the second pressure level.

A scroll plate for use in a scroll compressor is described. The scroll plate comprises a base plate having a first side and a second side, wherein the second side opposes the first side, and a spiral wrap formed on the first side of the base plate, wherein the base plate comprises one or more recesses and wherein an insulating material is located in at least one of the one or more recesses. Further, a scroll compressor having a corresponding scroll plate is described.

A pump body assembly, a compressor and an air conditioner. The pump body assembly includes: an upper flange. The upper flange includes a disc portion and a neck portion extending upward from the disc portion, an outer peripheral surface of the disc portion is connected with a housing of the compressor, a height a1 of the disc portion and a distance b1 between an upper end surface of the neck portion and a lower end surface of the disc portion satisfy: 0.3≤a1/b1≤0.4, and the height a1 of the disc portion and a diameter d1 of the disc portion satisfy: 0.1≤a1/d1≤0.2.

Rotary positive displacement pump having a one-piece drive housing provided with an opening with a closing cover and with bearing seats engaging at least one bearing, wherein a primary drive shaft and a secondary drive shaft are each rotationally engaged to the bearings of the opposite bearing seats of their own axis, each drive shaft being provided with at least one gear which is interposed between the opposite bearing seats, and wherein each drive shaft engages a positive displacement screw rotor placed within a stator body, the positive displacement screw rotors being intended to enable the generation of a product flow between a product inlet duct and a product outlet duct with which the product section is provided, and wherein the gears are monolithic and at least one of the gears is keyed to the drive shaft by a keying device for hollow shafts.

Positive displacement machine such as a compressor, expander, pump or the like, for displacing a gaseous or liquid medium, the machine containing an element with at least one inlet and at least one outlet for the medium and at least two cooperating driven moving parts. The mutual periodic movement of the moving parts displaces the medium from the inlet to the outlet. Each of the at least two driven cooperating moving parts is provided with its own individual drive. The element is provided with a kinematic synchronisation coupling between the at least two cooperating moving parts for the mutual kinematic synchronisation of their movements.

In a scroll compressor, at an end plate surface of a fixed scroll, an annular back pressure groove connected to a back pressure chamber is provided, and an arc-shaped first groove and an arc-shaped second groove are provided inside the back pressure groove in a radial direction. A distance between the second groove and the back pressure groove is shorter than a distance between the first groove and the back pressure groove. A revolving scroll is provided with a first hole and a second hole for guiding lubricant oil from an oil supply path to the end plate surface side of the fixed scroll. At least part of a movement locus of an opening of the first hole is included in the first groove. At least part of a movement locus of an opening of the second hole is included in the second groove. The first groove and the second groove at least partially overlap with each other in the radial direction.

A rotor assembly and a compressor are provided. The rotor assembly has a crankshaft, a rotor core, a balance weight and an oil baffle shield. The rotor core is provided with a vent hole. The vent hole extends through the rotor core along an axial direction of the rotor core. The balance weight is located at one end of the rotor core approximate to an oil sump of the compressor. The oil baffle shield is arranged to cover the balance weight and is provided with a central opening. The crankshaft extends through the central opening. An accommodating space is defined between the oil baffle shield and the rotor core. The accommodating space is communicated with the vent hole.

A pump body assembly includes: a crankshaft, a first baffle plate and a second baffle plate. The crankshaft includes a first eccentric portion, a support shaft and a second eccentric portion which are arranged at intervals in an axial direction; the first baffle plate and the second baffle plate are arranged in sequence between the first eccentric portion and the second eccentric portion, a first round hole is arranged defined on the first baffle plate, the support shaft is arranged in the first round hole, so that the first baffle plate and the support shaft form a baffle plate bearing, and the baffle plate bearing has a stress relief structure for reducing a contact stress between the support shaft and the first baffle plate.