Direct-drive gas pressure washers
A"Direct Drive"pump has a hollow shaft,which simply slides onto the drive shaft of a engine and the flange on the pump is mounted to the face of the engine,so the pump spins at the same speed as the engine—typically 3600 RPM.This system has the advantage of being simple,with few moving parts,and therefore is less expensive.The disadvantage is by having the pump spin as much as the engine the bearings get more wear and tear,reducing the life span of the pump.
Belt-drive gas pressure washers
Belt-drive units use pulleys and belts to slow the speed of the pump.Where the engine spins as 3600 RPM the pump will be slowed from 1100 to 1600 RPM depending on the pulley and belt set up.This system ensures long pump life because the bearings do not get as much wear and the pump is isolated from the heat of engine,being separated by the belts and pulleys.The disadvantage of this system is there is some loss of efficiency due to the additional friction from the belts and pulleys and more maintenance required adjusting the belts.
Gear-drive gas pressure washers
Gear-drive unit use an extra gear-reduction system installed between engine and pump,Gear Drive installation will not only keep the heat transfer down,but also make the pump turn at half speed which will result in longer life of the pump bearings and seals. Compare with belt drive system,the gear drive unit features more compact and less efficiency loss.This consequently makes such machines industria and allows the pump continuously running.
Life time compare chart
The pump life chart is a rough way of comparing the average pump life of the different gas drive systems based upon how much the pump spins over the life of the system.All other things being equal,the slower the pump spins,the longer the pump will last due to bearing life and the wear and tear on internal parts.The way the pump is used and exposing the pump to adverse conditions like running dry,in extended by-pass,freezing,or cavitation coupled with insufficient maintenance will significantly affect how long the pump lasts in actual conditions.