A system may include a compressor including a compression mechanism having first and second compression members defining a compression pocket disposed between the first and second compression members that decreases in volume during operation of the compression mechanism. A heat exchanger receives compressed working fluid from the compressor. An expansion device may be disposed downstream of the heat exchanger. A lubricant separator receives lubricant and working fluid discharged from the compression mechanism and provides separated lubricant to the compression mechanism. A lubricant-injection flow path may include a lubricant fitting and extends between the lubricant separator and the compression pocket such that separated lubricant is injected into the compression pocket through the lubricant fitting.

A pump device for pumping a liquid, has a hydraulics housing (12), in which a pump ring (14) with a contact surface (46), a pump ring support (16) and an eccentric (18), which can be driven by a shaft (20), are accommodated. The hydraulics housing (12) has an annular portion (22) and a first and a second lateral section (24, 26), the two lateral sections (24, 26) being arranged opposite each other. The pump ring (14) is mounted between the two lateral sections (24, 26) of the hydraulics housing (12) at least in some portions. The profile of the contact surface (46) has a contour with a curvature that changes at least in portions, and specifically in such a way that the curvature increases at least in some portions towards the ends of the contact surface (46).

A mud motor stator or a pump comprising of a tubular outer portion; a number of lobes extending radially inwardly from the tubular outer portion, at least one of which comprises a skeletal structure and method for producing a mud motor stator or a pump comprising of placing material and bonding the material together in a pattern dictated by the design shape of the stator or pump.

A pump unit which has at least one high-pressure port and at least one low-pressure port, having a motor and a hydraulic pump which has at least one high-pressure outlet and at least one low-pressure outlet, wherein the high-pressure outlet is connected to the high-pressure port via at least one pressure-regulating valve.

A scroll compressor includes an orbiting bedplate which has an oil passage through which oil flows outward in a radial direction of the orbiting bedplate, a lap-side oil supply hole that causes the oil passage to communicate with a lap-formation surface of the orbiting lap, and a thrust-surface-side oil supply hole that causes the oil passage to communicate with a thrust surface of the orbiting bedplate that is opposite to the lap-formation surface of the orbiting bedplate. An opening and closing mechanism provided in the oil passage closes the thrust-surface-side oil supply hole when the pressure of oil that is drawn from an oil sump by an oil pump and supplied into the oil passage is low, and opens the thrust-surface-side oil supply hole when the pressure of the oil is high.

The present application provides a slide valve, wherein the slide valve is configured to regulate a load of a twin-screw compressor. The slide valve comprises a slide valve body, wherein the slide valve body has a connecting end and a free end, the connecting end is configured to connect to a slide valve connecting rod of the twin-screw compressor, and the slide valve is driven to slide by the slide valve connecting rod. A cavity is formed in the free end of the slide valve body, and the slide valve has a passage configured to fluidly couple the cavity with an external fluid to reduce air flow pulsations on a suction side of the twin-screw compressor and thereby reduce overall air flow pulsations in the twin-screw compressor.

The utility model relates to internal cycloidal gear mechanisms and can be used in various branches of mechanical engineering as working members of hydraulic machines (pumps and engines), compressors, internal combustion engines, as well as in planetary gearboxes, in particular in technical systems for drilling and repairing oil and gas wells. The problems to be solved by the utility model include the improvement of the quality of the process of designing working members having a cycloidal tooth profile, as well as the substantiation of the conditions for modifying cycloidal face profiles (by choosing the required combination of dimensionless gearing coefficients) in order to achieve the maximum or minimum open area of the gerotor mechanism having a different kinematic ratio.

A scroll compressor includes a housing; a motor provided in the housing; a rotating shaft rotated by the motor; an orbiting scroll orbitally moved by the rotating shaft; a fixed scroll forming a compression chamber together with the orbiting scroll; and a valve mechanism guiding intermediate pressure refrigerant from an outside of the housing to the compression chamber and discharging refrigerant overcompressed in the compression chamber into a discharge chamber, thereby increasing amount of refrigerant discharged from the compression chamber, and improving performance and efficiency.

A scroll-type compressor includes a compression-chamber-forming member, a housing, an injection passage part, and a relief mechanism. The compression-chamber-forming member forms a compression chamber and has a movable scroll and a fixed scroll. The housing forms a back pressure chamber. Refrigerant to apply back pressure to the compression-chamber-forming member is accumulated in the back pressure chamber. The injection passage part is linked to the compression chamber. The relief mechanism is configured to establish a communication between the compression chamber and the back pressure chamber communicating when injection pressure of the refrigerant flowing from the injection passage part into the compression chamber is higher than the pressure in the back pressure chamber.

A gerotor assembly is provided which includes a crankshaft, an inner drive gear, an outer driven gear and a housing defining an oil groove. The inner drive gear defines a plurality of inner gear teeth. The outer driven gear defines a plurality of outer gear teeth operatively configured to engage with the inner gear teeth. The outer drive gear may define a plurality of passageways to form a hydrodynamic film between the outer driven gear and the housing. Alternatively, a high pressure oil pump may feed oil into the oil groove in order to distribute a hydrodynamic film.