Composite dry vacuum pump having roots and screw rotors
Patent 5549463 Issued on August 27, 1996. Estimated Expiration Date: 
March 3, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
March 3, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 1626768 3146717 3182670 Mechanical pumps Hydrodynamic fume scrubber Reactor chamber self-cleaning process Fluid rotating apparatus Fluid rotating apparatus with rotor communicating path Fluid rotating apparatus Fluid rotating apparatus with plural drive motor synchronization system InventorAssigneeApplicationNo. 398441 filed on 03/03/1995US Classes:418/3, DIVERSE ROTARY EXPANSIBLE CHAMBER DEVICES418/9, Interengaging rotary members418/200With axially spaced working membersExaminersPrimary: Vrablik, John J.Attorney, Agent or FirmForeign Patent References
International ClassesF04C 023/00F04C 025/02 Foreign Application Priority Data1994-11-24 JPAbstractA composite dry vacuum pump of this invention has closed chambers accommodating a pair of screw rotors and a pair of roots rotors respectively mounted coaxially to the front ends of the screw rotors. The roots rotors and the screw rotors are rotated at the same speed in opposite directions by a motor to aspirate fluids from a suction port on one end wall and discharge the fluid through a discharge port on the outer surface of the other end wall. The characteristics of power requirement of the portion of the roots rotors and that of the portion of the screw rotors changes inversely to the suction port pressure variation, therefore the characteristic of the total power requirement of the pump of this invention is almost flat over the all pressure range and the motor having smaller output power can operate the pump according to the present invention. Furthermore, the pump of this invention having the roots rotors coaxially assembled on the front end of the screw rotors makes a device containing this pump more compact one. | |
