HYDRAULIC A7VO..LRD Variable #Pump -1

https://www.facebook.com/M.Naguib.fouda #VARIABLE_PUMP_REXROTH Variable Pump of Bent-Axis Design for Open Circuits * High Pressure Applications The A7VO is a variable pump with an internal drain for open hydraulic circuits. The bent-axis rotary group is characterized by its robustness and good self-priming properties. The drive shaft bearings also allow external forces to be absorbed. For particularly demanding requirements in terms of force absorption and running time, type A7VLO has a rotary group with specially strengthened bearings. The swivel angle of the rotary group is changed by moving the control lens along a spherical surface by means of an adjusting piston. Increasing the angle increases the pump flow and the required drive torque. Reducing the angle reduces the pump flow and the required drive torque. The maximum angle is e.g. 25o or 26,5o. The minimum 0o. The pump is controlled as a function of the operating pressure and adjusted by means of external control signals. The necessary control pressure is taken from the pressure side via a check valve. * Constant Horsepower Control LR (see Spring-Loaded Control/Hyperbolic Control) The control holds the pump input torque M [Nm] constant. The constant horsepower control is a function of this constant torque in combination with a constant input speed n [1 /min]. On one side we have the input mechanical drive power P = M • n [kW], on the other the hydraulic output power P = Q • p [kW]. While operating pressure p [bar] is dependent on load, flow Q [I/min] can be varied by changing the swivel angle. Similar to a computer, the control continuously multiplies pressure and flow, and compares the result with the set value. Any upward drift is corrected by reducing the swivel angle and, inversely, by increasing the swivel angle. The control is adjustable (screwing in the setting screw increases the set value). Start of control is at max. swivel angle. The position at end of control is dependent on the maximum pressure. Alternatively, both end values can be limited by the stop screws. Warning: if the maximum set angle is increased there is a danger of cavitation in the pump and of over-speeding of the hydraulic motor! Increasing the minimum set angle can lead to overloading of the prime mover in the high pressure range. #VARIABLE_PUMP_REXROTH https://www.facebook.com/M.Naguib.fouda