A method of detecting leakage in a pump (10) that has at least one displacement body (12) for displacing a medium to be pumped into a pressure line (20), the method including the steps of: a) closing-off the pressure line (20), b) operating the pump (10) with a known speed of the displacement body (12), c) measuring the pressure (P) in the pressure line (20), d) repeating the steps b) and c) with different speeds, and e) recording the dependency of the measured pressure from the speed, wherein the speed of the displacement body (12) is program-controlled to increase, starting from a minimum speed, gradually to a maximum speed, the maximum speed being calculated on the basis of the measured pressure rise.

A vacuum pump includes a fan including a rotational speed to be controlled to cool the vacuum pump, a temperature sensor, and a control device that regulates the rotational speed of the fan in dependence on a power consumption of a drive of the vacuum pump and on a temperature measured by the temperature sensor. Another vacuum pump includes an electrically driven fan, an air guide hood, and a conductor that leads from the fan to a supply connection for the fan. The conductor is connected to the supply connection via an electrical connector. The connector is separated from an air flow path, defined by the air guide hood, by a partition wall.

A compressor unit including a screw compressor having a compressor housing that has a screw rotor chamber arranged in the compressor housing, two screw rotors that are arranged in the screw rotor chamber and are mounted on the compressor housing to be rotatable about a respective screw rotor axis, and at least one control slider, which is arranged in a slider channel of the compressor housing, is adjacent to both screw rotors and is movable in a direction of displacement parallel to the screw rotor axes and takes a form such that it affects the final volume and/or the initial volume, wherein there is provided on the screw compressor a compressor operational control unit that takes a form such that it performs a compressor operating function that assists at least one operation of the compressor unit.

A fluid machine device includes a plurality of fluid machines that discharge a fluid; a worn state detection unit that detects a worn state of the fluid machine; a pressure detection unit that measures a pressure from the fluid machines; and a control unit that controls the plurality of fluid machines. The control unit determines whether or not there is the fluid machine that is worn, and performs control to start operation of the fluid machine that is not worn when the pressure is insufficient.

A compressor, a monitoring system and a method of monitoring a compressor that make it possible to monitor the remaining lifetime of a semiconductor element of a motor control system while the processing load is reduced are provided. A compressor (1) includes: a motor control system (10) that controls the rotation speed of a motor (2); a compressor body (3) that compresses air by being driven by the motor (2); a pressure sensor (20) that is provided on the discharge side of the compressor body (3); and a running controller (11) that performs switching between load running and no-load running on the basis of the pressure sensed by the pressure sensor (20). A motor controller (26) of the motor control system (10) calculates a relative temperature of a semiconductor element relative to a reference temperature by using a temperature of the semiconductor element sensed by a temperature sensor (27) at the time of switching from no-load running to load running, and calculates an amount of change in a remaining lifetime of the semiconductor element corresponding to the relative temperature of the semiconductor element, whereby monitoring the remaining lifetime of the semiconductor element.

The invention relates to a method for controlling a rotary screw compressor, having at least a first and a second air-end, wherein both air-ends are driven separately from one another and speed controlled. According to the invention, the following steps are carried out: detection of a volume flow taken at the outlet of the second air-end; adjustment of the rotational speed of both air-ends, when the removed volume flow fluctuates in a range between a maximum value and a minimum value; opening of a pressure-relief valve, if the volume flow falls below the minimum value; and reduction of the rotational speed of at least the first air-end to a predetermined idling speed (V1.sub.L) to reduce the volumetric flow delivered by the first to the second air-end.

Method for operating and in particular monitoring a scroll pump, with the steps of: producing a vacuum by means of the scroll pump; determining a pressure of the scroll pump; comparing the recorded pressure with a pre-set threshold value; and if the recorded pressure lies above the pre-set threshold value, emitting a warning signal. The invention furthermore concerns a scroll pump for executing the method.

A pump apparatus which can more accurately determine the occurrence of an abnormal vibration. The pump apparatus includes: a pump; an electric motor for driving the pump; an inverter as a speed changing means for the electric motor; a vibration detector for detecting at least one of a vibration of the pump, a vibration of the electric motor and a vibration of the inverter; and a controller for controlling the pump. The controller includes a storage unit for storing a measured vibration value measured by the vibration detector. The storage unit has a storage table which, when the rotational speed of the pump is increased stepwise to a predetermined rotational speed, stores the measured vibration value measured at each step.

Provided are a compressor and a monitoring system that can specify a cause of an anomaly of a sensed value of a sensor. A compressor (1) includes: a temperature sensor (11A) that senses a temperature of a compressed air on a discharge side of a low-pressure-stage compressor body (3) and on an upstream side of an intercooler (5); a pressure sensor (12A) that senses a pressure of the compressed air on the discharge side of the low-pressure-stage compressor body (3); a temperature sensor (11B) that senses a temperature of the compressed air on an intake side of a high-pressure-stage compressor body (6) and on a downstream side of the intercooler (5); a temperature sensor (11C) that senses a temperature of the compressed air on a discharge side of the high-pressure-stage compressor body (6); a controller (8) that decides whether or not an anomaly has occurred in sensed values of the sensors (11A), (11B), (11C), and (12A), and estimates a cause of the anomaly; and a display device (9) that displays the cause of the anomaly estimated by the controller (8).

The invention relates to a scroll pump comprising a pressure sensor integrated into the scroll pump.