Small power unit gives trailers a lift

Elkhart, IN -When Mark Eichhorn, the engineering manager at trailer jack assembly manufacturer Equalizer Systems, needed a new way of providing a lifting device for trailers, he didn't have much space available in the jack assembly. "In our applications, every inch counts," he says.

Eichhorn now uses Micro-Pack MP90 Series hydraulic power units from SPX Fluid Power (Rockford, IL) in lifting and leveling devices on the front end of the trailer jack assemblies. Eichhorn points out that the pump's compact 3.75 x 5.50 inch size is important to his company's products. "Our previous lifting units were two inches longer in each dimension," says Eichhorn. "That limited us."

"We reduced the pump's size by incorporating the pump into the center plate," says Othello Garganera, a mechanical engineer and product manager at SPX Fluid Power. "When we took the power unit's pump out of the reservoir, the reservoir became shorter, but we were still able to maintain a relatively large volume of oil in a small space." The large volume of oil enables the Micro-Pack MP90 to generate pressures up to 3,000 psi in a compact unit-enough for lifting the trailer jack's heavy loads.

When designing trailer assemblies, tight spaces often translate into performance limitations. Using the small MP90 hydraulic power units opened new markets for Equalizer Systems. "We now install the units on horse trailers, race-car trailers, and use it for motor home leveling," says Eichhorn.

With other power units, the bolts were in awkward positions and became difficult to reach. "When designing the MP90 Micro-Pack, SPX made sure the bolting was easily accessible," says Garganera.

Valve options for the MP90 power unit include adjustable and tamper proof valves and pressure compensated flow controls. Additional applications for the power unit include small commercial truck-mounted cranes, truck cab tilting, and wheelchair lifts.

For more information about hydraulic power units from SPX: Enter 538