JUNE-JULY 2018 Digital copy | Page 69

book in series Integrated motor pump The motor/pump unit can be installed as a single block in special applications. This special design has two important advantages: less space is needed as the coupling has no bell housingand the prime mover is cooled down because the oil is sucked through the motor itself (Figure 4.75). Yet, we must stress that in this device the heat resulting from the efficiencies of the circuit and the electric motor is yielded to the oil, which warms up quickly. This unit is therefore suitable for intermittent operation unless a good heat exchange is guaranteed in continuous operation. Figure 4.73 Load sensing pressure control performs tasks that are similar to the previous one, but displacement variation does not depend on the pressure over the outlet of the generator but on the real pressure of the actuator. The power controller guarantees a constant force on the actuators by acting on the pressure/flow parameters (Figure 4.72). The electronic proportional control ensures better results (Figure 4.73). Transducers on the swash plate and the valve (depicted in the drawing on the rod of the inclination piston and next to the solenoid) guarantee high performances. More transducers and different hydraulic valves can adjust pressure/flow parameters in many different ways. Figure 4.75 Figure 4.74 Figure 4.76 JuNe-july 2018 | Global MDA Journal | 69