A variable hydraulic pump include a rotor mounted on a pump housing of which a housing spring end is formed, a pivot pin, an outer ring rotatably coupled to the pivot pin and of which a ring spring end is formed, a spring mounted between the housing spring end and the ring spring end, a pressure chamber formed in the pump housing to push the outer ring, a plurality of vane provided to form a plurality of pockets, an input port to supply oil to the plurality of pockets and a discharge port to exhaust oil supplied to the plurality of pockets, wherein at the reference position of the outer ring, the angle between a first imaginary line connecting the center of the rotor and the pivot pin and a second imaginary line connecting the ring spring end and the pivot pin is 0 to 10 degrees.

A positive displacement pump has a casing with a central body and two closing lids, the central body being provided with two cylindrical communicating chambers, one suction pipe and one discharge pipe, and two rotors revolvingly mounted in the chambers of the central body and supported by shafts revolvingly mounted in the closing lids. The two rotors include a male rotor having only protuberances, not cavities, and a female rotor having only cavities, not teeth or protuberances.

This electric horizontal scroll compressor (1) comprises an oil reservoir (13) in which lubricating oil that is separated from refrigerant passing through a compressing mechanism (20) is temporarily stored, and an oil return flow channel (15, 24) by which lubricating oil stored in the oil reservoir (13) is returned further upstream than the compressing mechanism (20). A main bearing (35) is fit into a holding face (14a) of an inner housing (14) by way of a clearance fit, and lubricating oil stored in the oil reservoir (13) is supplied to the region of the fit via the oil return flow channel (15, 24).

A screw compressor includes a screw rotor, a casing, and a delivery side shaft sealing unit. The delivery side shaft sealing unit includes an annular groove, a seal ring, and a shaft sealing fluid supply passage. Pressure of the fluid that is supplied to the one side, in the axial direction, of the seal ring via the shaft sealing fluid supply passage is set higher than pressure that acts on a first side surface, in an axial direction with respect to a first side wall surface of the annular groove, of the seal ring.

An embodiment of method used to control operation of a screw compressor of a refrigeration system may include receiving status signals regarding operation of the screw compressor of the refrigeration system. The method may further include determining an operating point of the screw compressor based upon the received status signals, and selecting a torque profile for the screw compressor based upon the operating point. The method may also include driving the screw compressor per the selected torque profile. Refrigeration systems and compressor systems suitable for implementing the method are also presented.

An embodiment of method used to control operation of a screw compressor of a refrigeration system may include receiving status signals regarding operation of the screw compressor of the refrigeration system. The method may further include determining an operating point of the screw compressor based upon the received status signals, and selecting a torque profile for the screw compressor based upon the operating point. The method may also include driving the screw compressor per the selected torque profile. Refrigeration systems and compressor systems suitable for implementing the method are also presented.

A disposable metering pump is made of plastic for products having solid fractions. The disposable metering pump has two rotors (10) which are coupled to each other by means of gears (11), can be driven in opposite directions, and are supported in a pump housing (5). Each rotor (10) has a rotor shaft, the rotor shaft ends (15) of which are supported in the walls of the pump housing (5). Each rotor (10) has two rotor blade walls (13), which are arranged diametrically opposite on the rotor shaft. One partially cylindrical rotor blade shoe (14) is formed at each of the peripheral ends of the rotor blade walls. The rotor blade shoes (14) lie against the cylindrical inner wall regions of the pump housing (5) in a sliding and sealing manner.

A high efficiency, thermodynamically interactive power system incorporating a “thermodynamic battery” operating in the cryogenic range. The “thermodynamic battery” is drawn upon to optimize the efficiency of power generation during times of peak demand and is “recharged” during periods of low demand. The system is ideally suited for (although not limited to) micropowerplants suitable for widely distributed generation of power in or associated with homes and small businesses, reducing transmission loading on the grid and capable of supplying power into the grid during peak load periods. The widely distributed power generation made practical by present inventions also enables distribution of heating and chill service locally on a much larger scale than is possible with large, centralized generation plants. A novel form of gear pump mechanism makes possible inexpensive and effective multi-stage compression and expansion of gaseous working fluid particularly suitable for incorporation into micropowerplants for distributed and localized power generation.

Provided is a tip seal that makes it possible to improve the durability of a tip seal installed on the tooth tip of a wall even when a continuously inclined section is provided to the wall. The tip seal is provided with: a tip seal inclined section (7A) installed in a groove section of a wall in which the height changes continuously in a spiral direction; and a tip seal flat section (7B) that is installed in a groove section of the wall in which the height is fixed in the spiral direction and that is adjacent to the tip seal inclined section (7A). A recess (8) is formed at a position away from the adjacent area between the tip seal inclined section (7A) and the tip seal flat section (7B).

A rotor pair for a compressor block of a screw machine includes a secondary rotor that rotates about a first axis and a main rotor that rotates about a second axis. The number of teeth of the main rotor is 3 and the number of teeth of the secondary rotor is 4. The relative profile depth of the secondary rotor is at least 0.5 rk1 is an addendum circle radius drawn around the outer circumference of the secondary rotor and rf1 is a dedendum circle radius starting at the profile base of the secondary rotor. The ratio of the axis distance of the first axis from the second axis and the addendum circle radius rk1 is at least 1.636.