In order to reduce the effect on a compressor caused by foaming in an oil tank, a control unit for controlling an oil pump starts the oil pump before a compressor is started (SA1), starts the compressor (SA4) when an oil supply differential pressure P satisfies a compressor startup condition during a reference time Tas from the starting of the oil pump (“Yes” in SA3), and extends the operation of the oil pump for a prescribed time without starting the compressor (Step SA5) when the compressor startup condition is not satisfied (“No” in SA3).

The present invention relates to a linear compressor. The linear compressor according to an aspect of the present invention includes a spring axially elastically supporting a driving assembly. The spring includes a spring body axially extending, a front spring link forming an end of the spring body by extending from a side of the spring body, and a rear spring link forming the other end of the spring body by extending from the other side of the spring body. Any one of the front spring link and the rear spring link is fixed to the driving assembly and the other one is fixed to a supporting assembly.

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.

Systems and methods for providing lubricant from a first compressor to a second compressor are provided. A control module receives a start command for a climate-control system having the first and second compressors, allows lubricant from the first compressor to flow into an inlet of the second compressor, turns the second compressor to an ON-mode, and prevents lubricant from the first compressor from flowing into the inlet of the second compressor after the second compressor has been in the ON-mode for a predetermined time period.

A scroll compressor includes an oil circulation pipe having one end inserted through a casing to be connected to an oil storage space inside the casing and another end connected to a suction passage for supplying refrigerant from outside of the casing to a compression chamber, an oil circulation valve disposed between the both ends of the oil circulation pipe to selectively open or close the oil circulation pipe, and a controller to control an opening or closing operation of the oil circulation pipe to reduce or eliminate frictional loss due to a shortage of oil by adjusting an oil level of the oil storage space at an initial operation.

An apparatus includes a suction header, a drain leg, an oil separator, and an oil reservoir. The suction header is configured to receive a refrigerant and the drain leg is coupled to the suction header. The oil separator is configured to separate an oil from the refrigerant from a compressor. During a first mode of operation, the drain leg is configured to collect an oil from the refrigerant from a compressor at the suction header. During a second mode of operation, the oil separator is configured to direct the oil separated from the refrigerant from the compressor through the drain leg and to the oil reservoir.

A linear compressor includes a spring axially elastically supporting a driving assembly. The spring includes a spring body axially extending, a front spring link forming an end of the spring body by extending from a side of the spring body, and a rear spring link forming the other end of the spring body by extending from the other side of the spring body. Any one of the front spring link and the rear spring link is fixed to the driving assembly and the other one is fixed to a supporting assembly.

In order to reduce the effect on a compressor caused by foaming in an oil tank, a control unit for controlling an oil pump starts the oil pump before a compressor is started (SA1), starts the compressor (SA4) when an oil supply differential pressure P satisfies a compressor startup condition during a reference time Tas from the starting of the oil pump (“Yes” in SA3), and extends the operation of the oil pump for a prescribed time without starting the compressor (Step SA5) when the compressor startup condition is not satisfied (“No” in SA3).

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).

The lubricant level within a reservoir is difficult to monitor, leading to the reservoir being refilled more often than necessary to ensure that the reservoir always contains lubricant. A lubricant level sensing system is connected to and monitors various aspects of the pump assembly that draws lubricant from the reservoir. The pump assembly displaces a known volume of lubricant with each pump stroke. A lubricant-level estimator calculates an estimated lubricant level remaining in the reservoir based on a stroke-count value as sensed from the pump assembly and on a reference value stored in a memory. The estimated lubricant level provides the lubricant remaining and the rate of usage such that maintenance can be scheduled ahead of time to prevent the reservoir running dry.