Gear pump
The gear pump is a machine for transferring liquids and for force-transmitting power hydraulic motors. It is a subspecies of the positive displacement pump.
Construction
The gear pump is basically composed of three parts:
- Housing with inlet and outlet
- Two gears (one powered )
Depending on the arrangement and size of the gears, a distinction between external, internal gear, gear pumps and screw pumps.
The external gear pump with involute the medium to be transported in the spaces between teeth and housing. The pump is robust and inexpensive by the simple construction.
In the internal gear and the ring gear pump driving gear runs eccentrically in the internal teeth of a ring gear. In the annular gear pump, the medium is conveyed through the changing in volume displacement space between the tooth spaces. In the crescent pump, the medium to be conveyed is fed into the spaces between the tooth gaps of the two gears, wherein the teeth (shown in the drawing, yellow) by the sickle sealed. Both designs also differ in the relative sizes of gear and ring gear. While the outer ring of a ring gear pump has exactly one more tooth than the inner gear and having a generally trochoidal, there are in the internal gear pump or sickle outwardly significantly more teeth than the inside.
Another name for the annular gear pump is Eaton pump according to its developer or rotor pump. At a rotor pump gears are referred to as rotors. Most rotors have very few teeth.
For screw pump is special in that it has helical chambers.
Properties
A gear pump delivers evenly (apart from the hydrostatically induced pulsation), the medium to be pumped and can tolerate medium pressures up to 400 bar. The pressure is as in any hydraulic system through the promotion of the medium against a load -in. If the load increases, the pressure increases.
Applications
- Drive for hydraulic power converter ( hydraulic motors or single / double acting power cylinder ) in construction machinery, tractors and in trade and industry, in particular vehicle
- Circulating cooling circuits
- Funding as the oil pump during combustion engine of the automobile and oil burners; Promotion of high-viscosity liquids ( melting), to be supported at high temperatures and under high pressures
The gear pump is also used most frequently as an engine oil pump in car engines. Screw pumps are due to the low noise frequently in stage hydraulics. Internal and external gear pumps are used very often in hydraulic systems. Gear pump ( Gearpump ) also are used in the production of rubber compounds used where they press the mixture through the filter, so-called screen.
History
The invention of the gear pump is not uniformly documented. On the one hand you back to Johannes Kepler in 1604; other hand, Gottfried Heinrich Graf zu Pappenheim is called, is said to have designed the capsule blower with two axes of rotation for conveying air and water. His gear pump according to other sources 1636 have supplied a fountain with water; Count Pappenheim died, however, already in 1632.