Provided is an air compressor which helps to attain a proper discharge air temperature and which is superior in energy saving property. There are provided an air line connecting an air compressor, an oil separator, and an after cooler; an oil circulation line connecting the air compressor, the oil separator, and an oil cooler; a bearing oil supply line connecting one end of an intermediate branching portion disposed at an intermediate point of the oil circulation line between the oil cooler and the air compressor to a bearing oil supply portion of the air compressor; an intermediate portion oil supply line connecting the other end of the intermediate branching portion to an intermediate oil supply portion of the air compressor; a branching line supplying oil to the bearing oil supply portion and the intermediate oil supply portion; a blower sending air to the oil cooler and the after cooler; a bypass line connecting one end of a bypass branching portion disposed at an intermediate point of the oil circulation line between the oil separator and the oil cooler to the downstream side of the oil cooler of the bearing oil supply line; and a control valve controlling the inflow amount of the lubricating oil to the bypass line.

A lubrication bypass system is disclosed for controlling flow of a lubricant to a reciprocating machine, such as two-stroke engines and two-stroke compressors, based upon one or more operating parameters. The lubrication bypass system can be positioned in fluid communication with a lubrication system that transports a primary flow of the lubricant from a lubricant reservoir to the reciprocating machine cylinder at a predetermined primary flow rate. The lubrication bypass system can be configured to divert a portion of the primary flow, a bypass flow, from the lubrication system at a bypass flow rate based upon the operating parameters. As a result, a secondary flow of lubricant remaining within the lubrication system can be supplied to the reciprocating machine at a secondary flow rate that is less than the primary flow rate. In this manner, the lubrication bypass system can regulate the secondary flow rate.

A compressor system includes: at least one variable-speed compressor, at least one fixed-speed compressor, a main suction pipe and a main discharge pipe; respective suction pipes of the variable-speed compressor and the fixed-speed compressor are connected to the main suction pipe in parallel, and respective discharge pipes of the variable-speed compressor and the fixed-speed compressor are connected to the main discharge pipe in parallel. The main suction pipe is configured with an oil-gas separation fitting structure, and the oil-gas separation fitting structure is designed to enable most oil of oil-gas mixture from the main suction pipe to move into the variable-speed compressor, and to make the variable-speed compressor stay in an oil-rich state.

A piston compressor may prevent excessive oil from accumulating in a crank chamber while securing the supply of oil to a swash plate. In a piston compressor in which an oil separation passage is formed in a shaft and a crank chamber communicates with a suction chamber through the oil separation passage, a supply passage opens at a region of a cylinder block opposed to a swash plate to allow a working fluid introduced from a discharge chamber into the crank chamber to be supplied to the swash plate and a bypass passage allowing the crank chamber to constantly communicate with the suction chamber is provided to prevent the accumulation of excessive oil in the crank chamber regardless of the operation condition. The bypass passage communicates with the crank chamber at a region positioned in the outer side of a rotation trajectory of the swash plate in the radial direction.

A method for monitoring an oil level of an oil-lubricated compressor, the method including: reading at least one oil level sensor, by which an oil level representing the compressor oil level is detected; checking compliance with at least one predetermined verification criterion for verification of the read-out oil level; and relaying an oil level signal if the read-out oil level complies with at least one relaying criterion according to whether the oil level reaches or falls below a predetermined oil level and with the at least one verification criterion.

A pump assembly with at least one liquid space (32) in an interior. The liquid space (32) contains a liquid or is configured for receiving a liquid. A sensor (34, 42) is arranged in the liquid space (32), which sensor is configured to detect at least one material property of the liquid located in the liquid space (32). A filter element (44) is arranged in the interior of the liquid space (32) such that the filter element (44) shields the sensor (34, 42) with respect to the surrounding liquid space (32), the filter element (44) being permeable to the liquid. A method for controlling a pump assembly is also provided.

Provided is an air compressor improved in terms of reliability by taking into consideration of the condensation of the water vapor in the compressed air. According to the present invention, an air compressor includes: a compressor main body; a compression chamber of the compressor main body compressing sucked-in air; an oil supply port supplying a lubricating oil to the compression chamber; an oil separator separating compressed air discharged from the compression chamber and the lubricating oil from each other; oil temperature adjustment means adjusting temperature of the lubricating oil supplied to the oil supply port; control means controlling the oil temperature adjustment means; sucked-in air temperature detection means detecting temperature of the sucked-in air; and sucked-in air humidity detection means detecting humidity of the sucked-in air, wherein the oil temperature adjustment means is controlled on the basis of detection information of the sucked-in air temperature detection means and of the sucked-in air humidity detection means.

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.

An air conditioner and a control method thereof are provided. The air conditioner includes: a compressor including a coil; an oil pool connected to the compressor through an oil piping; a main control board configured to receive a power-on signal of the air conditioner, obtain an actual temperature of the oil pool after receiving the power-on signal, generate a required heating amount in response to the actual temperature of the oil pool being lower than a preset startup temperature, and generate timing control signals according to the required heating amount; a power device, wherein two sides of the power device are respectively connected to the main control board and the coil, and the power device is configured to drive the coil to heat the oil pool according to the timing control signals generated by the main control board.

A refrigerant compressor unit, including a compressor housing and at least one compressor element that is arranged in the compressor housing, is movable by bearing and drive parts, and operates in at least one compressor chamber, at least one lubricant supply point arranged in the compressor housing for at least one of the bearing and drive parts and/or compressor element, and a lubricant supply line to the at least one lubricant supply point, wherein the lubricant supply line has a lubricant storage chamber through which lubricant flows and in which a lubricant presence sensor is arranged for detecting the presence of lubricant in the lubricant storage chamber.