The new series of in-line filters developed by Bosch Rexroth, Charlotte, N.C., the 110 LE(N) Series, has a filter head that uses the cyclone effect to keep heavier particles away from the filter, which keeps the filter from becoming clogged as quickly as filters in traditional designs. This extends the life of the filter and reduces maintenance.
Incoming hydraulic fluid gets diverted away from the filter and toward the outer wall of the aluminum bowl, creating a downward spiral or cyclone of fluid that forces heavier contaminants away from the filter and towards the bottom of the bowl where they collect. Keeping larger particles from clogging the filter lets the filter last 6 to 8% longer than those in conventional in-line devices.
A spring holds the six-layer, glassfiber- paper filter in place, which prevents swirling fluid from damaging it while keeping the filter from vibrating. The filter bowl is shaped so that fluid flows down and around the filter with uniform pressure. This means all filter surfaces do the same amount of work in removing particles. The filter is rated for particles ranging from 3 to 100 m. The filter works in temperatures from –22 to 212°F. Maximum operating pressure is 1,595 psi.
A differential-pressure contamination sensor measures how dirty the filter is. When the filter needs to be changed, the sensor activates a mechanical maintenance indicator, as well as an electrical indicator on top of the housing. When technicians replace the filter, a spring lifts it off its centering pivot inside the bowl, which simplifies the task.