A dry-type primary vacuum pump includes an injection device to distribute a purging gas in the pumping stages. The injection device includes: a first pressure sensor arranged on a common portion of the distributor, a second pressure sensor arranged on each branch of the distributor, and a control unit to generate a pulse width modulation command signal for the control of the regulation valves independently of one another as a function of the pressure measurement differences between the first pressure sensor and the second pressure sensors.

A dry type primary vacuum pump is provided, including at least two pumping stages mounted in series between a suction and a discharge of the pump; two rotors extending in the pumping stages and being configured to rotate synchronously in a reverse direction to drive a gas to be pumped between the suction and the discharge; an injection device configured to distribute a purge gas in at least one pumping stage, the injection device including at least one injector and at least one injection valve with an on or off control configured to be interposed between a purge gas supply source and the injector; and a control device configured to control opening and closing of the injection valve to inject a purge gas by successive pulses into the at least one pumping stage. A method for controlling the injection of a purge gas the vacuum pump is also provided.

A pumping system is provided, including a rough-vacuum pump; a Roots vacuum pump including a pumping stage having a stator inside which two Roots rotors are configured to rotate synchronously in opposite directions to drive a gas to be pumped between an inlet orifice and an outlet orifice; and a pipeline connecting the outlet orifice to an intake of the rough-vacuum pump, a shortest distance between an edge of the outlet orifice and each of the Roots rotors in the pumping stage being less than 3 cm, and the outlet orifice being situated at the end of an upstream tube of the pipeline that passes into the pumping stage.

The present disclosure provides a product removal apparatus, a treatment system, and a product removal method that can sufficiently remove the products deposited inside a vacuum pump and also suppress corrosion of the base material of the vacuum pump. The product removal apparatus of the present disclosure includes: a sensor for measuring the temperature of the inside of a vacuum pump, the thickness of a film of a product in a flow path in the vacuum pump, or the vibration frequency of the vacuum pump; a gas supplier for supplying a gas containing hydrogen halide, fluorine, chlorine, chlorine trifluoride, or fluorine radicals to the vacuum pump; and a control device. The control device controls the gas supplier so that the supply of the gas to the vacuum pump is stopped depending on a rate of temperature increase calculated from the temperature measured by the sensor, the film thickness, or the vibration frequency.

An eccentric bush assembly structure of a scroll compressor, in which an orbiting scroll is eccentrically coupled to a rotary shaft of a drive motor, including a bush body rotatably coupled to the orbiting scroll while being pinned to the rotary shaft of the drive motor by an eccentric shaft, the bush body having a friction prevention groove formed in a surface facing a tip surface of the rotary shaft so as not to come into frictional contact with the tip surface.

A deposit detection device for an exhaust pump is provided, which can be easily put into operation without the burdens of, for example, installing equipment for flowing a gas, or adding or changing operation modes in apparatuses. The device is configured to include: a means for detecting motor current values a motor that rotates a rotating body; a current value storage portion that stores only motor current values that are equal to or greater than a preset value from among detected motor current values; an average value calculation portion that calculates an average value per unit time of the stored motor current values; an average value storage portion that stores the calculated average value; an approximation calculation portion that determines a linear approximation of the stored chronologically ordered average values; and a difference value calculation portion that determines a difference value between a predicted motor current value calculated by using the linear approximation and an initial motor current value at a start of use of the exhaust pump. A time when the difference value exceeds a predetermined threshold is determined as a time for maintenance of the exhaust pump.

In order to prevent excessive motor loading or system overheating due to the accumulation of particulate or dust, from SACVD type CVD processes, in the running clearances of the vacuum pump a vacuum pumping arrangement is provided having a plurality of vacuum pumping stages and comprising a first pump inlet through which process fluid from the vacuum chamber can enter the pump and pass through each of the pumping sections towards a pump outlet, and a second pump inlet through which process fluid can enter the pump and pass through only one or more pumping stages downstream of the most upstream pumping stage, wherein the apparatus configured to conveying process fluid from the vacuum chamber to the first pump inlet for pumping during the second processing step and conveying process fluid from the vacuum chamber to the second pump inlet for pumping during the first processing step.

A control device that controls a target vacuum pump including a motor, including: a decision unit that decides, using at least one of target state quantities at a time of a past stop process of the target vacuum pump or another vacuum pump wherein the target state quantities are state quantities which fluctuate in accordance with a load at a time of a process of stopping a vacuum pump, a normal fluctuation range or a normal time fluctuation behavior of the target state quantity at the time of the stop process; and a control unit that controls the motor, wherein the control unit compares the target state quantity at the time of the process of stopping the target vacuum pump with the normal fluctuation range or the normal time fluctuation behavior, and changes a method of controlling the motor during the stop process depending on the comparison result.

A method is provided for controlling a temperature of a vacuum pump of a dry vacuum pump type subjected to variable pumping loads, the pump including a stator, a pumping stage, two shafts extending into the stage and respectively bearing a rotor to rotate synchronously in opposite directions in the stator and to drive a gas from a suction inlet to a delivery outlet, a cooling element coupled to the stator, a temperature sensor to measure a stator temperature, and a controller to control the stator temperature by the cooling element and the temperature sensor; and the method including controlling the pump temperature by the cooling element based on a temperature setpoint and a measurement of the stator temperature, and monitoring whether a value of a pumping load parameter is below a load threshold and, if so, increasing the setpoint. A vacuum pump and a system are also provided.

A pumping system is provided, including a rough-vacuum pump; a Roots vacuum pump including a pumping stage having a stator inside which two Roots rotors are configured to rotate synchronously in opposite directions to drive a gas to be pumped between an inlet orifice and an outlet orifice; and a pipeline connecting the outlet orifice to an intake of the rough-vacuum pump, a shortest distance between an edge of the outlet orifice and each of the Roots rotors in the pumping stage being less than 3 cm, and the outlet orifice being situated at the end of an upstream tube of the pipeline that passes into the pumping stage.