A rotary compressor may include a case, a cylinder, a roller, a vane, a main bearing and a sub bearing, and a discharge passage defined in the main bearing or the sub bearing to discharge refrigerant compressed in a compression space. The discharge passage may include at least one discharge hole formed through the main bearing or the sub bearing, and at least one discharge guide groove having a first end that communicates with the at least one discharge hole and a second end that extends from the at least one discharge hole toward a contact point between the cylinder and the roller and is recessed from one surface of the main bearing or the sub bearing forming the compression space. Accordingly, an amount of refrigerant remaining in the compression space even after a discharge stroke may be reduced.

A vane pump includes: a rotor; vanes freely slidably received in the rotor; a cam ring having a cam face with which the vanes come into sliding contact; a side member having a sliding contact surface with which side surfaces of the rotor and the vanes come into sliding contact; pump chambers; and a discharge port configured to guide working fluid discharged from the pump chambers. The side member has a guide surface that is provided on an end portion side of the opening portion, the guide surface being configured to push the end portions of the vanes upward and guide them toward the sliding contact surface of the side member as the rotor is rotated in the reverse rotation direction.

A hydraulic pump for a vehicle includes a pump housing, an inlet port formed to the pump housing, a chain cover combined with the pump housing and forming an outlet port with the pump housing, and a rotor provided between the pump housing and the chain cover and having a predetermined thickness, the rotor including an inner gear and an outer gear. The outlet port includes a center port having the same thickness as the rotor, a housing port formed to the pump housing and having a first depth and a cover port formed to the chain cover and having a second depth, and a sum of the first depth and the second depth is 50% to 60% of the thickness of the rotor.

A screw compressor includes a casing having an outer peripheral wall, and a compression mechanism. The compression mechanism includes a screw rotor with helical grooves, a gate rotor with a plurality of gates meshing with the helical grooves, and a cylinder housing the screw rotor. The compression mechanism is disposed inward of the outer peripheral wall. The outer peripheral wall has a discharge passage through which a fluid compressed in the compression mechanism flows. The discharge passage includes an inner peripheral passage formed along an outer peripheral surface of the cylinder, and an outer peripheral passage formed along the inner peripheral passage and the outer peripheral wall. The inner and outer peripheral passages are formed so that the fluid compressed in the compression mechanism sequentially flows through the inner and outer peripheral passages.

An electrical motor vehicle vacuum pump arrangement includes a housing assembly which includes an inlet opening arrangement having an inlet opening, an outlet opening arrangement having an outlet opening and an outlet channel, a pump unit having a pump rotor housing with an inlet-side end wall, an outlet side end wall, and a pump rotor housing part arranged therebetween, a drive motor having a motor rotor and a motor stator, sound absorption elements, and a sealing connected to the pump rotor chamber and directed towards the outlet opening. The outlet opening arrangement is connected to one of the sound absorption elements. The outlet channel of the outlet opening arrangement is closed relative to the drive motor and the pump unit. The outlet channel of the outlet opening arrangement, when viewed in a direction of the outlet opening, comprises at least one abrupt change in cross-section.

A scroll compressor includes a housing; a motor provided in the housing; a rotating shaft rotated by the motor; an orbital scroll orbital moved by the rotating shaft; a fixed scroll forming a compression chamber together with the orbital scroll; an injection flow path guiding an intermediate pressure refrigerant from an outside of the housing to the compression chamber; and an injection valve assembly opening and closing the injection flow path, wherein the injection valve assembly includes a cover plate having an inlet through which the intermediate pressure refrigerant is introduced, an injection valve opening and closing the inlet, and a valve plate having an outlet guiding the refrigerant that has passed through the injection valve toward the compression chamber. Thereby, an amount of refrigerant discharged from the compression chamber is increased, and thus the performance and efficiency of the compressor may be improved.

Disclosed herein is a scroll compressor including a casing, a drive motor arranged in the casing, a shaft coupled to the drive motor, a main frame arranged under the drive motor, a fixed scroll arranged under the main frame, an orbiting scroll arranged between the main frame and the fixed scroll and engaged with the fixed scroll to form a compression chamber with the shaft eccentrically coupled to the orbiting scroll, a discharge cover coupled to the fixed scroll to form a closed space, a discharge port formed in the fixed scroll to connect the compression chamber and the closed space, and a discharge hole passing through the main frame and the fixed scroll, wherein an inlet and an inner portion of the discharge hole have different cross-sectional areas. The scroll compressor can reduce the noise caused by movement of the refrigerant by improving the structure of the discharge holes.

A twin shaft pump may include two cooperating rotors configured to rotate in opposite directions about parallel axes of rotation; a stator comprising a stator bore in which the rotors are mounted to rotate. The stator bore includes a central part between the two axes of rotation, and an outer part outside of the two axes, the rotors being configured to have cooperating dimensions with the stator bore such that an outer edge of each rotor that is remote from the other rotor seals with the stator bore when rotating in at least a portion of the outer part. A fluid inlet is provided in the stator bore, at least a portion of the fluid inlet being in the central part of the stator bore between the axes of rotation. A fluid outlet is provide in an opposing surface of the stator bore, the fluid outlet being in the central part of the stator bore. The fluid inlet and fluid outlet are arranged such that on rotation of the rotors, the rotors each move a pumping chamber between the fluid inlet and the fluid outlet; wherein at least a portion of the fluid inlet is arranged to extend beyond the central part of the stator bore.

A rotary compressor may include a case, a cylinder, a roller, a vane, a main bearing and a sub bearing, and a discharge passage defined in the main bearing or the sub bearing to discharge refrigerant compressed in a compression space. The discharge passage may include at least one discharge hole formed through the main bearing or the sub bearing, and at least one discharge guide groove having a first end that communicates with the at least one discharge hole and a second end that extends from the at least one discharge hole toward a contact point between the cylinder and the roller and is recessed from one surface of the main bearing or the sub bearing forming the compression space. Accordingly, an amount of refrigerant remaining in the compression space even after a discharge stroke may be reduced.

A scroll type compressor includes an orbiting scroll including an orbiting wrap and a fixed scroll including a fixed wrap, in which first and second oil channels are respectively configured to supply oil to inner and outer oil channels formed by the orbiting wrap and the fixed wrap. Thus, the scroll type compressor has an oil channel structure that allows oil feeding into to the scrolls.