Rexroth Axial Plunger Pump A4VSO71EO2/10R-VPB25N00 A4VSO71EO2/10R-VZB13N00 A4VSO71EO2/10R-PZB13N00

The LR2 control can be upgraded with electronic proportional control for PLC integration, following these steps:

1. Install a Rexroth VT-VSPA1-1-1X proportional amplifier to convert PLC signals (4-20mA/0-10V) into hydraulic control signals
2. Connect the pump's power feedback sensor (R901500888) to the PLC's analog input module to form a closed-loop control
3. Use Siemens S7-1500 PLC to program adaptive logic -- for example, in a crane system, the PLC adjusts the 4-20mA signal based on boom load (measured by a load cell): 4mA (10% displacement) for no load, 12mA (50% displacement) for medium load, 20mA (100% displacement) for full load
4. Calibrate via Rexroth IndraWorks software to ensure signal linearity (error ≤1.5%)
5. Add a manual override switch for emergency operation. This upgrade reduces energy consumption by 25-30% compared to mechanical LR2 control.

Intermittent failure of power limiting is usually caused by unstable feedback or electrical interference:

1. Feedback Signal Instability: Check the power feedback sensor's wiring -- loose terminals or damaged shielding can cause signal fluctuations. Replace the sensor cable with a double-shielded type (Rexroth R900023456) and secure terminals with heat-shrink tubing
2. Control Valve Contamination: The LR2 valve's spool may stick intermittently due to fine particles. Disassemble the valve, clean the spool with ultrasonic cleaning (30 minutes, 40kHz), and reassemble with a new O-ring kit (R900912345)
3. Electrical Interference: If the pump is near high-voltage cables, install a signal filter (Rexroth VT-VRPA1-1-1X) between the amplifier and PLC to suppress noise (50/60Hz)
4. Pilot Pressure Fluctuation: Install a 0.3L accumulator in the pilot circuit to stabilize pressure (30-40 bar) during load spikes. After troubleshooting, test the power limiting function 10 times with varying loads to confirm stability.

Energy recovery integration leverages the pump's bidirectional potential (when used as a motor):

1. Hardware Configuration: Install a check valve (Rexroth SL 20 PA1-4X) and a high-pressure accumulator (50L, 350 bar) between the pump's pressure port and the crane's brake cylinder
2. Control Logic: When the crane lowers the boom (braking), the load drives the pump to rotate as a motor, charging the accumulator with high-pressure oil (via the check valve); when the boom lifts, the accumulator discharges to assist the pump, reducing the pump's load by 40-50%
3. Pressure Setting: Adjust the accumulator's pre-charge pressure to 180 bar (60% of the pump's working pressure) and set the pump's pressure limiting value to 350 bar (10 bar above the accumulator's maximum pressure)
4. Safety Measures: Install a pressure relief valve (420 bar) and a burst disc (450 bar) on the accumulator circuit to prevent overpressure. This system reduces fuel consumption by 15-20% in crane applications.