Comparison of Internal Gear Combined Gear Pump and External Gear Pump

Internal gear pump with involute gear pump and cycloid gear pump two. Cycloid gear pump, also known as the rotor pump, the two gears differ by a tooth. Internal gear pump is characterized by: small size, light weight, simple structure, easy manufacture, low price, reliable, self-priming performance is good, not sensitive to oil pollution, easy maintenance. The disadvantage is: large flow and pressure pulsation, noise, displacement and other variables. The characteristics of external gear pump: 1, the average flow of the gear pump is proportional to the number of teeth, and with the square of the modulus proportional 2, gear pump flow is proportional to tooth width, but the tooth width increases by the gear By the increase of hydraulic radial force limit, generally take the tooth width B = (6 ~ 10) m, high pressure take a small value. 3, increase the speed can increase the pump flow, but by the pump suction performance limits. Gear pump speed Generally in the 1000 ~ 1500r / min. 4, In addition, the displacement pump, gear pump flow pulsation maximum.Compared with the external gear pump, the main small, small flow pulsation, noise, etc., but the processing Difficult to use, the use is limited here at the meshing point of the tooth surface contact line has been played to separate the role of high and low pressure chamber, so gear pumps do not need to set a special flow control mechanism.