Armenia Intellectual Property Agency
Utility Model Number: 302 U
Date of Patent: October 3, 2012
Gear Pump with Different Teeth
Inventor: Varuzhan Harutyunyan, Nor-Nork 9th massive 97/7, 0059 Yerevan, Armenia
Application No.: AM20120085U
Filed: June 18, 2012
The invention concerns positive displacement rotary pumps and compressors.
An external gear pump in the field concerned is described in the book: A. G. Skhirtladze, V. I. Ivanov, V. N. Kareev “Gidravlicheskie i pnevmaticheskie sistemi” pages 94-101, published at 2006.
The utility model represents as positive displacement rotary pump.
Gear Pump with Different Teeth consists of a case, a pair of meshing cylindrical gears in it, two ports in the case: one for the liquid suction and the other one for the liquid discharge. The first gear rotates from actuator. The teeth of the gears have the same pitch diameter.
The first gear has two opposite big teeth, while the second gear has two opposite big cavities having the pitch greater than pitch of small teeth in 3, 5, 7 or more times. The addendum diameter of big teeth is greater than the addendum diameter of small teeth, whereas the dedendum diameter of big cavities is taken so, that a big tooth of the first gear can easily mesh with a big cavity of the second gear.
The reliability and effectiveness are enhanced.
Fig. 1 is an axonometric view of the gear pump with different teeth without cover
Fig. 2 is a plan view of the pump without cover
The external gear pump consists of meshing cylindrical gears and the case, which has two ports: one for liquid intake and the other one for its discharge. One of the gears receives rolling motion from actuator, while the other one rotates through meshing with the previous gear. The liquid is filled into the cavities between teeth and is delivered to discharge port along the case contour. The liquid cannot flow in the opposite direction because of the teeth strong meshing.
The pump has following limitations:
Since the suction occurs when a tooth of one gear leaves a cavity of the other gear, the pump generates low vacuum, which prevents its use for delivering high viscous liquids and limits suction head as well. Based on the suction and discharge nature, the pump has low admission and compression ratio, which results high volumetric losses after slight wear of teeth especially at high pressure. Because of the low compression ratio, the device cannot be used as compressor.
Gear Pump with Different Teeth consists of a case, a pair of meshing cylindrical gears in it, two ports in the case: one for the liquid suction and the other one for the liquid discharge. One of the gears rotates from actuator. The teeth of the gears have the same pitch diameter.
In addition, the first gear has two opposite big teeth, while the second gear has two opposite big cavities having the pitch greater than pitch of small teeth in 3, 5, 7 or more times. The addendum diameter of big teeth is greater than the addendum diameter of small teeth, whereas the dedendum diameter of big cavities is taken so, that a big tooth of the first gear can easily mesh with a big cavity of the second gear.