AZPT-020 AZPT-022 AZPT-025 AZPT-028 AZPT-032 AZPT-036 External Gear Pump REXROTH AZPS Series

The geometry of the displacement gearing, matched in formby the rotation of the drive shaft, results in the parabolic flowcharacteristic shown here on the left. In a standard pump, thischaracteristic is repeated each time a gear tooth meshes. Withtheir dual-flank system, the flow pulsation of SILENCE pumpsis reduced by 75%% - with correspondingly lower excitationof downstream system components - at double the fundamen-tal frequency. During this process, the gear pair exhibits anextremely reduced rear flank backlash, so that hydraulic sealingis provided not just by the front flank of the driven gear, butalso by the rear flanks. In this way, the front and rear flanksaltemately contribute to flow displacement. And by adaptingthe shape of the metering notches, the expansion of thehydraulic line of action is half that of the standard pump. Construction The external gear unit consists essentially of a pair of gearssupported in bearing bushings and the case with a front anda rear cover. The drive shaft protrudes from the front coverwhere it is sealed by the shaft seal ring. The bearing forcesare absorbed by special bearing bushings with sufficientelasticity to produce surface contact instead of line contactThey also ensure excellent resistance to galling - especiallyat low speed. The gears have 12 teeth. This keeps both flowpulsation and noise emission to a minimum.