Posted on September 29th, 2016
Most truck hydraulic systems consist of a gearbox driven PTO drive powering a gear pump. These systems work fine for a single telescopic cylinder used to lift a tipper bin at the back of a truck. Its a logical step to use this as the power source for the pump on a water truck. The trouble with even a well designed simple system is that the intensity of the water spray from the water pump is dependant on the speed of the drive at the gearbox at the PTO. Therefore water spray pressure varies with gear selection and engine speed. Often this setup is good enough, however sometimes an operator needs to be able to ensure a certain quality of spray regardless of operating conditions.
Our customer came to us with well defined specifications. They wanted their water truck pod to have two patterns, (a low speed as well as a high speed) depending on the coverage required. Furthermore they wanted the low spray pattern to be independent of vehicle speed. On top of that they had a fleet of trucks that were used with the various “pods”, so the system was to be used with different trucks, some of which would could have different flows and pressures.
Our “Hydraulic Solution” utilised a priority flow divider, with the priority flow giving the low speed. For the high speed pattern, both priority and excess were combined.
The module was mounted onto the water truck pods and connected to the various trucks in the fleet by hydraulic quick connectors. The result: water truck pods with performance that is independent the truck driving the pod or of engine speed and gear choice.