The present invention concerns a dry vacuum pump comprising: a drive device (1) comprising a drive shaft (3) at one end of which is fixed at least one drive wheel (4) provided to set in motion at least one belt (5); at least two parallel rotors (7, 8) each having a shaft (9, 10) provided with a rotor element (11, 12), this shaft (9, 10) being able to be driven in rotation by the belt (5) and being equipped at one of its axial ends with a toothed wheel (13, 14), this pump having the special features that: the drive wheel (4) and the belt (5) are smooth; each shaft (9, 10) of the rotor (7, 8) comprises at least one smooth section (16, 17) arranged to co-operate with the belt (5), and the toothed wheels (13, 14) of the shafts (9, 10) of the rotor (7, 8) are dimensioned and arranged to mesh with one another.

A pump body assembly, fluid machinery, and a heat exchange device. The pump body assembly includes: at least two structure members; a cylinder disposed between the two structure members; and a piston assembly disposed in the cylinder. The piston assembly includes a piston sleeve and a piston slidably disposed in the piston sleeve; an upper end surface of the piston sleeve fits and is limited by a lower end surface of one structure member disposed above the piston sleeve, to prevent the piston sleeve from displacing along a radial direction relative to the one structure member, and effectively solving a problem in prior art that working efficiency of the pump body assembly is affected because the piston sleeve of the pump body assembly is prone to eccentrically rotate.

A scroll compressor includes a casing; an orbiting scroll; a fixed scroll; and a main frame which supports the orbiting scroll. The fixed scroll may include a fixed scroll end plate and a fixed scroll wrap which protrudes from the fixed scroll end plate. The main frame may include a main frame end plate which is provided on the opposite side of the fixed scroll end plate on the basis of the orbiting scroll, and a main frame side plate which protrudes from an outer circumferential portion of the main frame end plate toward the fixed scroll. The fixed scroll end plate, the main frame end plate, and the main frame side plate may form an orbiting space of the orbiting scroll.

A fluid pump includes a rotor which is centered about an axis, the rotor having a rotor central chamber and a plurality of vane slots. A stator has a recess therein within which the rotor is located, the recess having a recess peripheral surface which is eccentric to the axis. Each vane slot includes a vane therein such that the vanes define a plurality of pumping chambers which expand and contract based on rotational position the rotor relative to the stator. A positioning ring is located within the rotor central chamber such that the positioning ring engages each vane and such that the positioning ring urges each vane into contact with the recess peripheral surface. The positioning ring is radially aligned with a midpoint of each vane.

An example crescent seal assembly comprises: an outer crescent of a gear pump; an inner crescent of the gear pump mating with the outer crescent such that an exterior peripheral surface of the inner crescent interfaces with an interior peripheral surface of the outer crescent, forming: (i) a spring cavity, (ii) a first check valve cavity, and (iii) a second check valve cavity therebetween; a spring disposed in the at least one spring cavity; a first check pin disposed in the first check valve cavity; and a second check pin disposed in the second check valve cavity.

A scroll compressor is provided that may include a casing having an oil storage space, a suction pipe and a discharge pipe being connected to the casing, a drive motor installed in an inner space of the casing and including a rotational shaft rotated by a generated drive force, a compression unit installed in the inner space of the casing and having a compression chamber operated by the drive motor to compress a refrigerant, an oil separator coupled to the discharge pipe, that receives refrigerant discharged after being compressed by the compression unit, separates oil from the refringent, and supplies the oil to an inside of the casing, and a subframe that rotatably supports the rotational shaft at one side of the rotational shaft. The subframe may be provided with an oil recovery flow path that extends in a radial direction and guides oil to be recovered toward the inside of the casing from the oil separator.

A scroll compressor includes a discharge guide disposed in a high-pressure part to guide refrigerant discharged from a compression part to a refrigerant discharge pipe, and the discharge guide may extend by a preset height from an inner circumferential surface of a casing constituting the high-pressure part toward one side surface of a high and low pressure separation plate. This can guide discharge refrigerant discharged to the high-pressure part to quickly flow to the refrigerant discharge pipe before being spread in an entire space of the high-pressure part, thereby preventing the high and low pressure separation plate from being overheated by discharge refrigerant of high temperature. This can result in preventing suction refrigerant of a low-pressure part from being heated by heat of discharge refrigerant transferred through the high and low pressure separation plate, thereby reducing a specific volume of the suction refrigerant and improving compressor efficiency.

A compression device includes at least: two interleaved scrolls each of which is made of an aluminum alloy, one of the scrolls, being a fixed scroll (3), and is fixed and the other scroll, which is an orbiting scroll and moves eccentrically without rotating. Also included are anti-rotation means made of an aluminum alloy and configured to allow anti-rotation of the orbiting scroll. The compression device also includes one flat thrust bearing configured to axially contain the orbiting scroll and is made of aluminum alloys or grades of cast iron. The compression device also includes coatings for promoting friction between the fixed scroll, the orbiting scroll, the anti-rotation means and the flat thrust bearing.

A method of manufacturing a slide of a variable oil pump for a vehicle includes preparing a molded body for a slide of a variable oil pump using prealloy powder including, in percent (%) by weight of the entire composition, 0.45 to 0.55% of carbon (C), 2.8 to 3.2% of chromium (Cr), 0.45 to 0.55% of molybdenum (Mo), 0.35 to 0.5% of manganese (Mn), 0.1 to 0.25% of sulfur (S), and the remainder of iron (Fe) and inevitable impurities. A sintered body is prepared by sintering the molded body. The sintered body is slowly cooled such that a temperature of the sintered body reaches a first temperature range and rapidly cooled when the first temperature range is reached.

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.