Roots Vacuum Pumps 2016 by Leybold

More catalogs by Leybold | Roots Vacuum Pumps 2016 | 40 pages | 2017-05-08


Page 10 of Roots Vacuum Pumps 2016

operating principle roots vacuum pumps which are also called roots blowers are rotary plunger type pumps where two symmetrically shaped impellors ­rotate in oppo­site directions inside the pump housing the figure-of-eight rotors are synchronized by a gear which ­ensures that the impellors are ­counter-rotating in such a way that they are near to one another and to the housing without actual ­con­tacting in rotor positions i and ii see figure “operational diagram of a single-stage roots vacuum pump with v­ ertical pumping action” the volume of the intake is increased as the rotors turn further to position iii a part of the vol­ ume is cut off from the ­intake side in position iv this volume is opened to the exhaust side and gas under forevacuum pressure higher than the intake pressure flows in this gas compresses the gas coming from the intake as the rotors turn further the compressed gas is ejected through the exhaust flange this process repeats itself twice for each rotor per full turn as the rotors do not come into contact with the pump’s housing roots vacuum pumps may be ­operated at high speeds thus a high pumping speed is obtained from comparably small pumps 10 operational diagram of a single-stage roots vacuum pump with vertical pumping action the pressure difference and the ­com­­pression ratio between intake and ex­haust is limited in roots v­ acuum pumps in practice the maximum attainable pressure difference is of significance only in the rough vacuum range ­ p 10 mbar p 7.5 torr where-as in the medium vacuum range p 1 mbar p 0.75 torr the attain­ able compression ratio is of importance roots vacuum pumps from leybold have been designed to specially meet the requirements of the fine vacuum range they are normally used in connection with backing pumps or in closed gas cycles wslf series leybold full line catalog fall 2016 design the pump chamber of roots vacuum pumps is free of any sealing agents or lubricants only the toothed wheels of the synchronous gear are lubricated with oil toothed gear wheels and bear­­ ings of the ruvac are placed in two side chambers which also contain the oil reservoir these two side chambers are ­separated from the pump chamber by piston ring seals suitably designed oil supply systems in both chambers ensure that a ­sufficient quantity of oil is supplied to the gear wheels and bearings at all permissible speeds almost all ruvac roots vacuum pumps are designed for a horizontal and vertical pumping action leybold