Pump Technology
Micropump utilizes a variety of positive displacement pump technologies in its wide range of precision, low flow pumps, including external gear, gerotor, peristaltic, multiple and single piston, and sliding vane. Also available are high performance centrifugal pumps in a very compact size.
External Gear Pumps
Consists of two or more rotating gears which mesh together. One of the gears is turned by a power source and drives the other gear(s). The spaces between the gear teeth carry the fluid from the inlet to the outlet. The gear mesh point prevents the fluid from returning to the inlet. Gear pumps are available in cavity and suction shoe styles, both of which provide pulseless delivery.
Gerotor Pumps
Are rotary pumps that are constructed with an externally toothed internal rotor as well as with an annular tooth external rotor, which bear slightly eccentric to each other. During rotation of the rotors around their offset axis, the pumping chambers simultaneously increase on the induction side and decrease on the delivery side of the pump. A homogeneous flow rate is generated between the kidney-shaped inlet and outlet.
Multiple and Single Piston Pumps
Multiple and single piston pumps use piston like rotor elements supported from swash plates inset into the pump endplate to move fluid through the pump.
Peristaltic Pumps
Tubing is used as the pump chamber and may be single or multichanneled. The fluid confined in the tubing is displaced when two or more rollers squeeze the tubing against the walls of the pump housing. Changing the tubing size or ther rotor speed will vary the flow rate. Maximum pressure capability is limited to the tubing.
Sliding Vane Pumps
Vanes are contained in a rotor, rotating in an eccentric housing. The fluid is trapped between the vanes and housing and is swept through the pump. It is similar to a flexible impeller pump, except the impeller blades or vanes are made of a rigid material.
Centrifugal Pumps
Consists of an impeller rotating within a casing. Liquid directed into the center of the rotating impeller is picked up by the impeller vanes and accelerated to a high velocity. When the liquid in the impeller is forced away from the center of the impeller, a reduced pressure is produced and consequently more liquid flows forward. There is no closed volume, like in a positive displacement pump, therefore, a steady flow through the impeller is produced. The pump basically increases the Bernoulli head of the flow between the eye and the exit of the pump.
