Proportional pressure control valves for differential locks

Increase efficiency by using compact, pilot-operated proportional pressure control valves

Mobile machines need to work efficiently under all kinds of conditions. A constant focus here is on low energy consumption—since the introduction of stricter guidelines, machine manufacturers also need to minimize exhaust emissions. For the operator, on the other hand, the mobile machine must, among other things, offer minimized noise emissions for increased comfort. As a result, control technology is facing major challenges.

But it's low operating costs that are often crucial here. Those who reduce their mobile machine's energy requirements sustainably reduce the costs for operators. As part of this, it is particularly important to further develop the machine’s functions and components. When looking at articulated dump trucks, it becomes clear that conventional proportional pressure control valves for differential locks lead to very frequent accumulator charging. This is due to high levels of leakage in the inactive state. This charging means that the large working pump needs to be activated in the next step. This costs a lot of energy—decreasing the efficiency.
HYDAC offers solutions that sustainably increase efficiency. Taking one of our customers as an example, we will demonstrate our expertise as an innovative problem solver.

In collaboration with our customer, the HYDAC specialists in fluid technology analyzed the cause of the high energy consumption of the differential lock in the articulated dump truck. On this basis, they developed something in complete contrast to conventional products with a large installation space and permanent leakage—a new, needs-based, and above all considerably more efficient solution.

Leakage-optimized and compact pilot-operated valves for high flow rates laid the foundation—these already contributed to increasing efficiency and weight savings. Building on this, our experts developed an innovative additional function that was the perfect answer to our customer’s requirements: the pilot-operated proportional pressure control valve PDMC12S30P-15. It impressed the customer with its patented pilot oil separation. An innovation that reduced leakage in an inactive state by a factor of 20. At the same time, the construction machine manufacturer benefitted from our unrivalled compact design for high flow rates up to 100 l/min.

Thanks to the significant reduction in leakage, the HYDAC solution led to considerably longer accumulator discharging times in the differential lock in the customer’s mobile machines. This didn’t just save the customer energy—the minimized charging times bring other real advantages. In addition to reduced noise generation and therefore increased comfort for the operator, the dump truck manufacturer also benefitted from minimized pump wear. This is because reduced wear means valuable conservation of resources: a cost advantage that really set them apart from the rest of the market. The benefits convinced our customer—to this day, our solution can still be found as a series solution in their products.