A gear pump is a type of positive displacement pump. Gear pumps use the actions of revolving gears to move fluids. The rotating gears create a liquid seal with the pump casing and generate suction at the pump inlet. The fluid that is drawn into the pump is enclosed within the teeth of the rotating gears and transported to the discharge. Today we’re discussing information related to the internal gear pump working principle in GA. There are two basic designs of gear pump – external and internal. An external gear pump consists of two duplicate, interlocking gears supported by separate shafts. An internal gear pump functions on the same principle but the two interlocking gears are of different sizes with one rotating inside the other. The rotor is an internal gear that has the teeth projecting on the inside. The Internal Gear Pump Working Principle In GA There are three stages in an internal gear pump’s working cycle – filling, transfer, and delivery. As the gears come out on the inlet side of the pump, they produce an expanded volume. Liquid flows into the cavities and is trapped by the teeth of the gears as they continue to rotate against the pump partition and casing. The trapped fluid is moved from the inlet to the discharge around the casing. As the teeth of the gears are interlocked on the discharge side of the pump, the volume is decreased and the fluid is forced out. Close tolerances between the casing and the gears allow the pump to produce suction at the inlet and prevent fluid from leaking back from the discharge side. The main Features And Benefits Of An Internal Gear Pump The internal gear pump working principle is simple and they are compacted with a limited number of moving parts. They are unable to match the pressure generated by responding pumps or the flow rates of centrifugal pumps, but they offer higher pressures and throughputs than lobe or vane pumps. Internal gear pumps have better suction abilities than external gear pumps and are more suited to high viscosity fluids. Because the output is directly proportional to rotational speed, internal gear pumps are commonly used for metering and blending operations. The low internal volume provides for a reliable measure of liquid passing through a pump and hence accurate flow control. The Main Applications For Internal Gear Pumps Some typical applications that work well with the internal gear pump working principle in GA include:

  • Fuel oil and lube oil;
  •  Resins and polymers;
  • Alcohols and solvents;
  • Asphalt, bitumen, and tar;
  • Polyurethane foam;
  • Food products such as corn syrup, chocolate, and peanut butter;
  • Paint, inks, and pigments;
  • Soaps and surfactants;
  • Glycol.

An internal gear pump moves fluid by repeatedly encompassing a fixed volume within interlocking gears and transferring it mechanically to deliver a smooth pulse-free flow proportional to the rotational speed of its gears. They are versatile and are able to operate across a wide range of fluid viscosities and temperatures. They are preferred to external gear designs in applications involving higher viscosity fluids, at high temperatures and with fluids containing solids. Typically, internal gear designs operate at lower rotational speeds than external gear designs, have greater clearances and are therefore less susceptible to wear in these applications. For the same reasons, internal gear pumps are also better suited to pumping shear-sensitive fluids. If you would like more information regarding the internal gear pump working principle in GA, call us today and speak to one of our experts.