A compressor system is provided that includes a contact cooled compressor and a coolant separator. The coolant separator is used to remove coolant fluid from a compressed flow stream produced by the contact cooled compressor during its operation. The coolant separator routes the removed coolant fluid back to the contact cooled compressor for further use. In some forms the coolant fluid is cooled prior to delivery back to the compressor. A stop valve can be provided in the coolant fluid return line to halt the flow of the fluid. A pressure sensitive member can be disposed to sense pressure of the coolant fluid that has been routed past the stop valve. Operation of the compressor can be changed as a result of the sensed pressure from the pressure sensitive member. Information from a temperature sensitive member can also be used to change operation of the compressor.

The present invention provides an oil feed type air compressor that can reduce a power consumption of a compressor body during an unload operation. The oil feed type air compressor includes: a compressor body (1) compressing air while feeding an oil into a compression chamber; a separator (4) disposed on a discharge side of the compressor body; a compressed air-feeding system (5) feeding the compressed air separated by the separator to a use destination of the compressed air; an oil-feeding system (6) feeding the oil separated by the separator to the compression chamber of the compressor body; an oil cooler (11) and a temperature sensor (12) disposed in the oil-feeding system; and a controller enabling execution of a temperature control. The temperature control by the controller is performed by variably controlling a rotation speed of a cooling fan (13) such that, during the load operation, a temperature detected by the temperature sensor is a target value T1, and during the unload operation, the temperature detected by the temperature sensor is a target value T2 (with the proviso of T1>T2).

An oil detecting device for a compressor and a compressor including an oil detecting device are provided. A casing in which oil is received has a plurality of capillary tubes in an inner space of the casing, and a condition of oil is detected on the basis of a result of a measured pressure from the plurality of capillary tubes.

Refrigerant compressor installation comprising at least three compressors which are arranged in parallel between an intake conduit and a pressure conduit and which each comprise a lubricant sump unit, wherein the compressors, when in operation, work in such a way that the respective pressures in the respective lubricant sump units of the respective compressors form a pressure cascade according to which the compressors have a successively slightly decreasing pressure in the respective lubricant sump unit in a defined cascade sequence, and wherein the lubricant sump units are connected to each other in a manner corresponding to the cascade sequence by way of a lubricant conduit system for lubricant transport, and wherein each lubricant sump unit comprises a port to which is connected an insert element which on the one hand establishes communication with the lubricant conduit system and on the other hand is configured such that it predetermines, for the respective lubricant sump unit, a lubricant level from which lubricant is transported to the lubricant sump unit that follows next in the cascade sequence.

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 compressor system can include a lubricant injection system useful to supply lubricant to an airend. The compressor system can include a variable lubricant flow valve which can be regulated by a controller on the basis of operating conditions of the compressor system. In one form the compressor system also includes an oil separator and/or an oil cooler with or without a thermal control valve. The controller can have one or more modes of operation, including a mode in which the controller regulates the flow of lubricant to the airend to increase an internal flow area of the valve when the airend is operated at an unloaded or loaded condition. In some forms the controller can regulate the lubricant flow valve and/or the thermal control valve and/or the lubricant cooler.

The present invention provides a co-rotating scroll compressor that can inhibit leakage of lubricant supplied to a synchronous drive mechanism. A co-rotating scroll compressor includes a drive-side plate 20 placed between a driving scroll member 70 and a motor 5 at a predetermined distance from the driving scroll member 70 in a direction of a drive-side rotation axis CL1. The drive-side plate 20 includes a shaft portion 20b fixed to a driving shaft 6 of the motor 5 and a fixing portion 20a fixed to an outer periphery of the driving scroll member 70, and a synchronous drive mechanism made up of a needle bearing 32a and a pin 32b is placed between the drive-side plate 20 and driving scroll member 70.

A compressor system includes: a compressor having a suction side and a discharge side, wherein the compressor is operative to compress a gas using oil, wherein the suction side operates at a suction pressure and is operative to receive a the gas and the oil into the compressor; and wherein the discharge side is operative to discharge the compressed gas and the oil; a gas/oil separator tank operative to store oil separated from the compressed gas for subsequent use by the compressor; a supplemental oil reservoir in fluid communication with the suction side; and a valve operative to, when opened, expose the supplemental oil reservoir to the suction pressure of the suction side of the compressor, and draw oil from the supplemental oil reservoir by suction into the suction side of the compressor.

Method for cooling a liquid-injected compressor element, where a liquid is injected in the compression chamber of the compressor element (2) via an injection valve (13). The method includes the step of adjusting the quantity of liquid which is injected in the compression chamber of this compressor element (2) as a function of a specific adjusting parameter, irrespective of any other possible adjustments. The quantity of liquid to be injected is adjusted by using a second injection valve (19), which has the shape of an adjustable valve to this end.

A Method for controlling the liquid injection of a compressor device or expander device. This compressor device includes at least one compressor element or expander element, whereby the element comprises a housing that comprises a rotor chamber in which at least one rotor is rotatably affixed by means of bearings, whereby liquid is injected into the element. The method comprises the step of providing two independent separated liquid supplies to the element, whereby one liquid supply is injected into the rotor chamber and the other liquid supply is injected at the location of the bearings. The separated liquid supplies are realised by means of a modular channelling piece of an injection module.