Increase the gear diameter, tooth width, speed and reduce the number of Melt Metering Gear Pump . Too high N will shorten the time for the gear teeth to rotate the suction chamber The increase of N and diameter increases the circumferential velocity and centrifugal force of gears. Increasing the difficulty of inhalation, P at the root of the tooth decreases, gas may be released, resulting in Q reduction, vibration and noise, and even make the pump unable to work. Therefore, the maximum circumfer