AA2FO90/61R-VQDN55

The AA2FO90/61R-VQDN55 hydraulic motor is produced by Bosch Rexroth for the A2FM Fixed Motors series. It supplies constant displacement power for automated pump drives and rotary actuators in hydraulic systems. The displacement is 90 cm³ per revolution, so each shaft turn transfers a predictable oil volume to downstream components. With a nominal pressure of 400 bar it develops 573 Nm of torque, enabling direct coupling to heavy-duty transmission shafts. Rotary stiffness of 9.14 kNm/rad limits torsional deflection, which maintains positioning accuracy under load. A small rotating group inertia of 0.0072 kg·m² supports rapid acceleration and deceleration sequences in servo-controlled loops. The unit is built for clockwise rotation when observed from the drive shaft end, simplifying circuit layout in standardized power packs. Maximum working pressure reaches 450 bar for short duration overloads, while the internal case volume of 0.55 L ensures adequate oil for cooling. FKM sealing elements resist high-temperature fluids and common hydraulic additives.

At 1800 rpm—the maximum speed allowed with a 1 bar inlet—the motor outputs 162 L/min of flow to drive cylinders or secondary pumps at planned rates. If the inlet is pressurized, permissible speed rises to 3350 rpm, providing higher power density when required. Inlet pressure may vary between 0.8 and 30 bar absolute, protecting the rotating assembly from cavitation yet accommodating boosted charge circuits. The assembled unit weighs 23 kg, allowing single-person handling during installation or maintenance. Service ports A and B follow the SAE J518 1-inch pattern, offering straightforward hookup to pressure and return lines, whereas the dedicated suction port uses the same standard in a 1-1/4-inch size to lower inlet velocity losses. These port dimensions integrate cleanly with common flange fittings and minimize installation time. Together, the flow capability, speed limits, pressure boundaries, and standardized interfaces define reliable performance in closed-loop and open-loop hydraulic automation.