The present invention describes a reciprocating compressor, comprising: an assembly block (10); a rotating shaft (20) comprising at least one inner axial channel (21), said inner axial channel (21) connected to at least one inner radial channel (22a, 22b) or to a cam (23); the cam (23) is associated with a connecting rod (24), and the connecting rod (24) is associated with a movable piston (25) within a compression cylinder (26); and an oil pump (C), comprising: an axial flow electric motor comprising a rotor (30), with magnets (31), and a stator (40) with coils (41); wherein the rotor (30) and the stator (40) are fixed to the shaft (20) and to the assembly block (10), respectively, by means of bearings or fixing arrangements.

A compressor includes: a shell forming an outer portion thereof and having lower part in which an oil pan is formed to store oil; a motor provided in the shell; a compression unit provided in the shell to compress a working gas when being driven by the motor; a frame fixed to the shell and supporting the compression unit; a shaft supported by the frame, connecting the motor and the compression unit, provided to transmit a turning force of the motor to the compression unit, and including an oil passage; and an oil pump provided at lower part of the shaft to draw oil from the pan and supply the oil into the oil passage. The pump includes a bypass valve that is opened, when a pressure of oil flowing in the oil passage is higher than a threshold pressure, to return part of the oil to the pan.

A lubricating oil supply apparatus having a structure in which a valve is forced in a direction for opening a bypass hole by a centrifugal force, and a spring presses the valve in a direction in which the valve closes the bypass hole. When the above-described structure is applied to an oil pump in which an oil (lubricating oil) supply amount increases in proportion to an operation speed, it is possible to secure a sufficient oil (lubricating oil) supply amount in a low speed operation mode, and prevent oil from being supplied more than necessary in a high speed operation mode.

A compressor includes a compression mechanism that compresses refrigerant; a main shaft that transmits a rotational driving force to the compression mechanism; a balance weight provided below the compression mechanism and integrated with the main shaft, the balance weight having a cylindrical outer peripheral surface centered at the main shaft; and an oil sump portion provided below the balance weight and stores lubricating oil to be supplied to the compression mechanism. The balance weight has an annular oil-receiving recessed portion in an upper surface, the oil-receiving recessed portion being centered at the main shaft and integrated with the balance weight. The balance weight has a hollow portion in a lower surface, the hollow portion extending in part of the lower surface in a peripheral direction around the main shaft and being integrated with the balance weight. The oil-receiving recessed portion communicates with at least part of the hollow portion.

A hermetic compressor includes: a compression unit; a motor unit; a crankshaft that connects the motor unit and the compression unit; and a bearing member provided with a shaft receiving hole so as to support the crankshaft in a radial direction. An oil supply groove that defines a part of an oil supply passage is formed on an outer circumferential surface of the crankshaft, and the oil supply groove is provided between the outer circumferential surface of the crankshaft and an inner circumferential surface of the bearing member facing the outer circumferential surface of the crankshaft to be located out of pressed regions generated when the crankshaft rotates. As the oil supply groove that supplies oil to a bearing surface between the crankshaft and a main bearing is formed by avoiding the pressed regions, oil may be smoothly supplied to the bearing surface.

A compressor includes a casing that stores a lubrication oil in a bottom portion, a compression mechanism disposed in the casing, an electric motor disposed above the compression mechanism, a discharge pipe opening in a space in the casing on an upper side of the motor, and an oil drainage mechanism that guides a lubrication oil adhering to an inner wall of the casing to the discharge pipe using a swirling flow generated by rotation of the motor. The oil drainage mechanism includes an oil drain pipe having one end opening in the inner wall of the casing and another end connected to the discharge pipe, and a flow-rate regulating valve disposed at the oil drain pipe. The flow-rate regulating valve has a changeable opening degree. The opening degree of the flow-rate regulating valve is configured to be regulated in accordance with a rotational speed of the motor.

A hermetic compressor may include a frame, a crankshaft, and an oil pump. The crankshaft may be rotatably mounted to the frame. The oil pump may be mounted to a lower portion of the crankshaft to be rotatable together with the crankshaft. The oil pump may pump oil from a lower region to an upper region of a shell using centrifugal force. The crankshaft may be provided with a hollow hole therein that is inclined in two directions with respect to an axial direction of the crankshaft. This may result in increasing a dynamic pressure for scattering the oil to the upper region of the shell and an oil supply amount.

A compressor according to an embodiment includes: a discharge valve; a discharge space formed downstream of the discharge valve; a liquid injection hole for injecting a refrigerant liquid into the discharge space; and a heat medium flow path located opposite to the discharge space across a partition wall forming the discharge space.

A lubricant holder for vertical conveying of lubricant using a crankshaft of a coolant compressor includes a sleeve element having a clear cross-section delimited by an inside wall, which cross-section extends along a longitudinal axis, from an upper end to a lower end, an inner element that has a mantle surface that extends along a longitudinal axis of the inner element, from a lower end to an upper end, wherein in an operating state the inner element is arranged within the clear cross-section with its mantle surface, at least in certain areas. At least one groove of the inside wall and/or of the mantle surface, which groove runs in spiral shape, has a varying angle of inclination, which preferably increases from the lower end to the upper end of the mantle surface.

Disclosed are a fluid pumping device and a horizontal compressor. The fluid pumping device comprises a pump structure in the form of an internal-meshing gear pump and is provided with first and second pump members, a pump housing structure for accommodating the pump structure, and at least two suction paths and/or at least two discharge paths. Suction and compression cavities are defined between the first and second pump members; the at least two suction paths are configured to rotate with the pump structure, and a fluid can be sucked into the suction cavity via the at least two suction paths respectively; and the at least two discharge paths are configured to rotate with the pump structure, and the compressed fluid can be discharged from the fluid pumping device via the discharge paths respectively. The fluid pumping device is assembled in the horizontal compressor.