Types of Pressure Washing Motor Pump and Their Advantages and Disadvantages
Let's explain the pros and cons of each type and get an in-depth look at how each works:
Drive shaft drives piston pump
Swing plate pump
An entry-level pump uses a wobble plate attached to the driveshaft to push the piston back and forth to create suction, which then pushes the water out.
Each piston has a large spring that allows the wobble plate to push towards them. This results in the pump being only 70% efficient as it has to push the water and the spring. Swing pumps are not economical to repair because they have many intricate parts that are difficult to reach and are hermetically closed at the factory.
Their lifespan is somewhat comparable to that of axial lobe pumps, around 200 – 400 hours (about 3 hours/week for 2-3 years).
Used for: Some pressure washers below 2500 PSI and low flow rates (less than 2 GPM).
Advantages: There is no seal that moves back and forth with the piston, self-priming, can run dry and can generate high pressure.
Cons: Many moving parts add complexity, and low flow. cannot be economically substituted. Not as efficient as other pumps.
Swashplate Pump (Axial Cam)
A mid-range pump that offers many advantages over swing and is capable of higher PSI and GPM. You can see in the animation below that it is similar to a swing, but with a slight difference that the piston actually rotates around the swash plate. The swashplate angle allows the piston to stroke as it sucks in water from one side and pushes it out the other. This operation allows for a larger oil tank and larger bearings for longer life. It rotates on the same axis as the drive shaft because it is directly connected.