The range of oil pumps is very broad. However, it is important to be aware that not every model will meet specific requirements. For this reason, it is worth learning about the basic categories of oil pumps. One of the most common classifications concerns their technology. In this respect, gear, centrifugal, arc, and vane pumps can be distinguished.
Gear Pumps
This is a positive-displacement rotary pump, which may have internal or external gearing. Gear pumps are characterized by a simple design, constant capacity, ease of use, and reliability. They work by drawing in liquid and then pumping it onward using gears. To drive the pump, it is enough to set one gear in motion, which then successively drives the others. The pump may have between two and five gears. It operates at a constant capacity, and its speed ranges from 500 to 900 gear revolutions per minute.
Centrifugal Pumps
These pumps operate using an impeller that rotates at a constant speed, creating suction at the inlet and excess pressure on the discharge side. What is more, the use of centrifugal force and buoyancy ensures a continuous flow of liquid. Centrifugal pumps are characterized by a simple design, low failure rate, low operating costs, high capacity, and relatively small dimensions. They are being used increasingly often and are displacing gear pumps from the market. Their disadvantages include the inability to self-prime and low resistance to contaminants in the pumped liquid.
Arc Pumps
These pumps have many applications and are suitable for pumping almost any liquid. An arc pump consists of two elements—a pumping tube and a drive. When liquid flows through the tube, the impeller is set in motion and the liquid is pumped to the surface. Arc pumps are characterized by ease of use, the ability to pump liquids of varying viscosity, and low weight.
Vane Pumps
They operate using an impeller fitted with vanes that collect the liquid as the pump operates and transfer it to the pump’s discharge chamber. Arc pumps are characterized by high efficiency (which means that smaller motors can be used than with gear pumps), quiet operation, and high resistance to contaminants in the pumped liquid.
