A compressor includes a casing with an oil retention space, an electric motor, a driveshaft, a compression mechanism, an oil supply passage, an oil discharge passage, an oil supply pump, and an oil discharge pump. The compression mechanism has a movable part, and an upper housing forming a crank chamber. The upper housing has an upper bearing that pivotally supports the driveshaft below the crank chamber. The oil supply passage leads oil in the oil retention space to the crank chamber. The oil discharge passage includes a main oil discharge passage, and a first inflow passage communicating between the main oil discharge passage and the crank chamber. An oil-recovery space is formed in a lower part of the upper housing below the crank chamber. The oil discharge passage includes a second inflow passage communicating between the main oil discharge passage and the oil-recovery space.

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 hermetic compressor includes an airtight case a lower portion of which oil is stored in; a frame received in the airtight case; a compression mechanism disposed in the frame and to compress a refrigerant; a motor mechanism including a stator fixed to the frame and a rotor to rotate inside the stator; a rotation shaft coupled to the rotor and provided with a cavity at a lower portion of the rotation shaft, wherein the rotation shaft rotates together with the rotor and operates the compression mechanism; a stationary shaft inserted into the cavity of the rotation shaft, fixed to the airtight case, and provided with a helical groove formed on an outer circumferential surface; and an oil raising member fixed to the cavity of the rotation shaft and configured to surround the stationary shaft. The oil raising member raises the oil stored in the airtight case.

A compressor includes a compression mechanism configured to compress refrigerant, an electromotive mechanism configured to drive the compression mechanism, a shell accommodating the compression mechanism and the electromotive mechanism, a reservoir provided inside the shell and configured to store mixed liquid including liquid refrigerant and refrigerating machine oil, and an electrode provided inside the reservoir and facing an inner surface of the shell.

A refrigerant compressor reserves lubricating oil in a sealed container, and accommodates therein an electric component, and a compression component which is driven by the electric component and compresses a refrigerant. At least one of slide members included in the compression component is made of an iron-based material, and an oxide coating film comprising a composition A portion, a composition B portion, and a composition C portion is provided on a slide surface of the iron-based material. The composition A portion is a portion containing diiron trioxide (Fe.sub.2O.sub.3) which is more in quantity than other substances, and is, for example, an outermost portion (160a). The composition B portion is a portion containing triiron tetraoxide (Fe.sub.3O.sub.4) which is more in quantity than other substances and containing a silicon (Si) compound, and is, for example, an intermediate portion (160b). The composition C portion is a portion containing triiron tetraoxide (Fe.sub.3O.sub.4) which is more in quantity than other substances and containing silicon (Si) which is more in quantity than silicon (Si) of the composition B portion, and is, for example, an inner portion (160c).

A refrigerant compressor comprises an electric component; and a compression component which is driven by the electric component and compresses a refrigerant. At least one of slide members included in the compression component is made of an iron-based material. An oxide coating film (150) is provided on a slide surface of the iron-based material, the oxide coating film including a first portion (151), a second portion (152), and/or a third portion (153). The first portion (151) contains at least fine crystals (155). The second portion (152) contains columnar grains (156). The third portion (153) contains layered grains (157).

A compressor includes a casing with an oil retention space, an electric motor, a driveshaft, a compression mechanism, an oil supply passage, an oil discharge passage, an oil supply pump, and an oil discharge pump. The compression mechanism has a movable part, and an upper housing forming a crank chamber. The upper housing has an upper bearing that pivotally supports the driveshaft below the crank chamber. The oil supply passage leads oil in the oil retention space to the crank chamber. The oil discharge passage includes a main oil discharge passage, and a first inflow passage communicating between the main oil discharge passage and the crank chamber. An oil-recovery space is formed in a lower part of the upper housing below the crank chamber. The oil discharge passage includes a second inflow passage communicating between the main oil discharge passage and the oil-recovery space.

An output shaft lubricating structure of a liquid pressurizing pump is provided. A first eccentric portion of an output shaft acts as the maximum stress for load when the liquid is pressurized and works. By the power of the output shaft, a telescopic piston of an oil supply device is directly pushed by a second eccentric portion to draw the lubricating oil in a circular core hole and to pressurize and supply the lubricating oil to an oil supply hole of the output shaft to force an oil outlet hole to drain the lubricating oil to the surface of the first eccentric portion for circulatory supplement, such that the turning of a turning wheel on the first eccentric portion can keep better lubrication for a long time so as to prolong the service life of the output shaft and the turning wheel.

A rotor core is configured by stacking a plurality of core plates each including: an inner peripheral side core portion; an outer peripheral side core portion; a magnet insertion hole; a radial connection portion to be connected to the inner peripheral side core portion; a circumferential connection portion to be connected between the outer peripheral side core portion and the radial connection portion, including a minimum width portion having a width smaller than widths at both ends, and having a width smoothly decreasing from both ends toward the minimum width portion; and a thin portion including a uniform thickness portion which is provided in the circumferential connection portion and which has a uniform thickness and a non-uniform thickness portion which is adjacent to the uniform thickness portion and which has an increasing thickness, the thin portion having the minimum width portion within the uniform thickness portion.

An oil feeder and a linear compressor including the same are disclosed. The oil feeder includes an oil cylinder defining an oil supply hole configured to extend in a first direction, an accommodation groove formed concavely at a side, and a communication hole configured to communicate the oil supply hole with the accommodation groove, an oil piston accommodated in the accommodation groove and configured to reciprocate in a second direction perpendicular to the first direction, a first ball accommodated in the oil supply hole and disposed below the communication hole, a second ball accommodated in the oil supply hole and disposed on the communication hole, and an elastic member comprising an outer portion coupled to the accommodation groove and an inner portion coupled to the oil piston.