The present disclosure relates to a turbo blower capable of operating in a surge area and, more particularly, to a turbo blower capable of operating in a surge area, the turbo blower increasing consistency of performance thereof and efficiency by preventing suspension thereof due to a temporarily generated surge by operating even in a surge area for a predetermined time in addition to a normal area in which the turbo blower normally operates.

An electric pump provided with a pump unit configured to discharge working oil by being rotationally driven by an electric motor includes: a drive shaft configured to transmit rotational driving force from the electric motor to a rotor of the pump unit; a rotation-detection shaft provided coaxially with the drive shaft, the rotation-detection shaft being configured to be rotated together with the rotor; and a rotation detector unit configured to detect rotation of the rotation-detection shaft. The rotation-detection shaft has: an engagement portion configured to engage with the rotor; and a detection-target portion facing the rotation detector unit, and an outer diameter of the detection-target portion is set so as to be larger than an outer diameter of the engagement portion.

Provided is an abnormality diagnosis device including: a physical quantity measurement processor configured to acquire, as time-series data, a physical quantity of an electric motor or a load; a feature parameter calculation processor configured to calculate feature parameters; a correlation function creation processor configured to create a correlation function for two or more feature parameters, and calculate a correlation coefficient corresponding to a measurement result of the physical quantity that changes depending on an abnormality occurrence state; a database configured to store in advance reference data in which a remaining time until a failure is caused and the correlation coefficient are associated with each other; and a diagnosis processor configured to extract from the reference data the remaining time corresponding to the correlation coefficient, and identify the remaining time until the electric motor or the load causes a failure or a part that has caused a failure.

The object of the disclosure is to prevent erroneous transition of an operation mode to an operation limitation mode. A control device 6 includes a controller 62. The controller 62 counts the number of times of occurrence of each of multiple types of abnormalities occurred in a vacuum pump 1, and issues a critical alarm in a case where the number of times of occurrence of each of the multiple types of abnormalities exceeds a predetermined threshold.

Provided is an abnormality diagnosis device including: a physical quantity measurement processor configured to acquire, as time-series data, a physical quantity of an electric motor or a load; a feature parameter calculation processor configured to calculate feature parameters; a correlation function creation processor configured to create a correlation function for two or more feature parameters, and calculate a correlation coefficient corresponding to a measurement result of the physical quantity that changes depending on an abnormality occurrence state; a database configured to store in advance reference data in which a remaining time until a failure is caused and the correlation coefficient are associated with each other; and a diagnosis processor configured to extract from the reference data the remaining time corresponding to the correlation coefficient, and identify the remaining time until the electric motor or the load causes a failure or a part that has caused a failure.

The present disclosure can provide a vacuum pump capable of obtaining a rotation direction and correcting the rotation direction without adding a dedicated rotation direction sensor even in a state of low-speed rotation. The control device is capable of obtaining at least a first state in which a rotor shaft rotates at relatively high speed, and a second state in which the rotor shaft deviates within a gap between the rotor shaft and a protective bearing and rotates at relatively low speed while revolving, acquires output information of a radial displacement sensor, obtains a rotation direction of the rotor shaft in the second state on the basis of the output information, determines whether the rotation direction is normal or not, and when the rotation direction is not normal, stops the rotation and increases rotation speed to achieve a normal rotation direction.

An altitude control system for an unmanned aerial vehicle includes a compressor assembly defining a plenum therein, a passive valve assembly coupled to a first portion of the compressor assembly and in fluid communication with the plenum, and an active valve assembly coupled to a second portion of the compressor assembly and in fluid communication with the plenum. A method of controlling an altitude of an unmanned aerial vehicle and an unmanned aerial vehicle are also provided.

A vacuum pumping device comprises: a turbo-molecular pump; an backing pump connected to an outlet side of the turbo-molecular pump; a measurement section configured to measure first elapsed time until a suction-port-side pressure of the backing pump reaches a predetermined pressure higher than a turbo-molecular pump startable pressure and lower than an atmospheric pressure after start of the backing pump; an arithmetic section configured to calculate, based on the first elapsed time measured by the measurement section, the atmospheric pressure, and the predetermined pressure, second elapsed time until the suction-port-side pressure reaches the turbo-molecular pump startable pressure after the start of the backing pump; and a start control section configured to start the turbo-molecular pump when the second elapsed time has elapsed after the start of the backing pump.

The invention relates to a compressor unit (200) for a refrigeration system using a refrigerant. The compressor (200) unit includes a centrifugal compressor (201) for compressing the refrigerant, wherein the compressor (201) has a discharge outlet (204) for discharging the compressed refrigerant, and a check valve (1; 100; 301a). An inlet (83) of the check valve (1; 100; 301a) is in fluid connection with the discharge outlet (204) of the compressor (201). In order to provide a more reliable and more quite compressor unit (200), the check valve (1; 100; 301a) is a nozzle check valve including a damping mechanism (41, 50; 50, 141), wherein a closing parameter of the check valve (1; 100; 301a) is between 50 s/m.sup.2 and 2000 s/m.sup.2, wherein the closing parameter is a closing time of the check valve (1; 100; 301a) divided by a port area of the check valve (1; 100; 301a).

A vacuum pump system is provided that includes a main vacuum pump that is connected to a chamber that is to be evacuated. An auxiliary pump is connected to an outlet of the main vacuum pump. Furthermore, a sealing gas supply device is connected to the main vacuum pump. The sealing gas supply device is switched on and off with the aid of a control device as a function of a predetermined control variable. Additionally, a method for controlling the vacuum pump system.