Machine provided with a machine element (2) and an oil pump (4) and a motor (3) to drive the machine element (2) and the oil pump (4), whereby the oil pump (4) is provided with a shaft (13) with a rotor (12), whereby the oil pump (4) is provided to pump oil from an oil reservoir (5) via an inlet channel (8) to nozzles that lead into the motor (3) and/or machine element (2) to lubricate and/or cool one or more bearings or other machine components, characterized in that in the inlet channel (8), near the oil pump (4) a dam (16) is provided that is higher than the height (A) of the central axis (18) of the shaft (13) of the oil pump (4) minus the smallest diameter (B) of the rotor (12) of the oil pump (4) divided by two.

A vacuum system having a condenser and a root vacuum pump set includes an independent inlet condenser set having an inlet end for receiving vapor inputted from an output of an air cooling power generator condenser of a generator; air in the vapor being condensed, and the surplus air is outputted; a root vacuum pump set including at least one root vacuum pump; the root vacuum pump set further including an input end and an output end; the input end being connected to the independent inlet condenser set; air outputted from the independent inlet condenser set being inputted to the at least one root vacuum pump for compression and then the compressed air being outputted from the output end; and a backing pump connected to the output end of the root vacuum pump set by using an output pipe; the backing pump serving to receive air outputted from the root vacuum pump set.

A vane pump includes: a rotor configured to rotate under rotational force from a rotary shaft while supporting multiple vanes and including a curved surface portion with an arc shape centered on the rotary shaft and a rotor recess depressed from the curved surface portion toward a rotation center; a cam ring disposed so as to surround the rotor and including an inner peripheral surface facing the curved surface portion of the rotor; and an inner plate disposed on one end of the cam ring in an axial direction of the rotary shaft so as to cover an opening of the cam ring and including a suction inner recess depressed toward the rotation center relative to the curved surface portion of the rotor.

A method of operating a vacuum pump system, the method including the steps of: operating a primary vacuum pump having a variable speed motor; connecting at least two secondary vacuum pumps in parallel with said primary vacuum pump; dividing the secondary vacuum pumps in groups, each group including at least one secondary vacuum pump; and assigning a priority for each of said groups. The method further includes the steps of measuring the inlet pressure p1, comparing the measured inlet pressure p1 with a predetermined pressure value p0, and if p1 is higher than p0, starting the secondary vacuum pump at a first predetermined startup load S.sub.startup,1 if it includes a fixed speed motor, and/or starting the secondary vacuum pump at a second predetermined startup load S.sub.startup,2, if it includes a variable speed motor.

A power saving vacuuming pump system is based on complete-bearing-sealing and dry-large-pressure-difference root vacuuming root pumps includes an input valve at an input end of a vacuum space for receiving gas mixture of saturation water vapor and non-condensed air from a condenser of a power plant; a first root vacuum pump connected to the input valve for receiving gas mixture from the input valve and then compressing the gas mixture; a second root vacuum pump connected to the first root vacuum pump for receiving gas mixture from the first root vacuum pump and then compressing the gas mixture. Inner connection walls between the vacuum chamber and the two bearing rooms are installed respective bearings which are installed to be around the driving shaft, and thus all the vacuum chamber and the two bearing rooms are tightly sealed. The vacuum chamber is completely dried so as to prevent from internal emulsion.

A complete bearing-sealed root vacuum pump system capable of promoting vacuum ability of a condenser of a power plant provides a complete bearing-sealed structure. All chambers are isolated effectively so that liquid cannot flow there between and thus not to destroy the root vacuum pump. Therefore, the lifetime of the root vacuum pump is prolonged. The heat exchangers are arranged between the root vacuum pumps and the front stage pump so as to return the condensed water. The condenser vacuum is improved and thus the power generation efficiency is promoted, and power consumption is lowered. As a result a large power plant can save several thousand tons of coals per year.

A power saving vacuuming pump system is based on complete-bearing-sealing and dry-large-pressure-difference root vacuuming root pumps includes an input valve at an input end of a vacuum space for receiving gas mixture of saturation water vapor and non-condensed air from a condenser of a power plant; a first root vacuum pump connected to the input valve for receiving gas mixture from the input valve and then compressing the gas mixture; a second root vacuum pump connected to the first root vacuum pump for receiving gas mixture from the first root vacuum pump and then compressing the gas mixture. Inner connection walls between the vacuum chamber and the two bearing chambers are installed respective bearings which are installed to be around the driving shaft, and thus all the vacuum chamber and the two bearing chambers are tightly sealed. The vacuum chamber is completely dried so as to prevent from internal emulsion.

An apparatus includes a sensor assembly disposable in a drill string proximate a drilling motor. The sensor assembly has a first pressure sensor in fluid communication with an upstream side of a rotor in the drilling motor, a second pressure transducer in fluid communication with a downstream side of the rotor and a rotational speed sensor coupled to the rotor. A processor is in signal communication with the first pressure transducer, the second pressure transducer and the rotational speed sensor.

A method for controlling the speed of a compressor with a controller as a function of the available gas flow. The method includes the steps of setting a desired value for the inlet pressure; determining the inlet pressure; and determining the speed. The method further includes controlling the speed of the compressor by reducing or increasing it depending on whether the inlet pressure is less than or greater than a set desired value until the inlet pressure is equal to the set desired value where the characteristic data of the compressor relating to the efficiency and/or the Specific Energy Requirement (SER) as a function of the speed and the inlet pressure is provided and the desired value of the inlet pressure is adjusted on the basis of the aforementioned characteristic data so that the efficiency of the compressor is a maximum or the SER is a minimum.

Control systems and methods for increasing efficiency of a compressor while the compressor capacity exceeds compressor load, by using a mechanical unloader such as a slide valve to reduce the internal volume ratio of the compressor and allow a more efficient speed to be maintained by a variable frequency drive (VFD) while reducing the compressor capacity based on the load. Control systems include the VFD, a controller for the VFD and the mechanical unloader, and temperature sensors. Compressor embodiments further include one or more compressors and mechanical unloaders operated by the control systems.