Why choose PTO Pump?

• Enhanced Performance: Significantly higher pressure (typical 25 bar vs 5 bar) and flow capabilities compared to commonly available pump systems
• Versatility: The same pump can still be used with a tractor when needed

Why automate it?

• Noise Reduction: Minimize noise level by operating the pump only as fast as necessary
• Energy Efficiency: Optimize power consumption by reducing motor speed and pressure
• Flexible Control: Microcontroller-driven system allows for easy integration of additional features (e.g. timeouts, remote-control)

High flow, medium pressure application

Mechanical

• Belt drive
  • Pulley motor: 2x13mm, d=100mm
  • Pulley PTO-shaft: 2x13mm, d=250mm
  • 2 x 13mm v-belt
• Expansion tank: 8 Liter
• Bypass valve: 3/4”
• Pressure relief valve: 10 bar
• PTO Shaft: 1 3/8” (34.9 mm)
• Bearings: 2x 35 mm roller bearings with clamping sleeve
• Various fittings, valves, couplings…

Main pipe assembly with flow sensor, bypass and pressure relief valve

Pump

• Name: ML 20
• Power: 4 kW
• Rotational speed:
  • Max: 700 rpm
  • Rated: 540 rpm
• Connection: 1 3/8”, 6 Tooth PTO shaft
• Max. Pressure: 25 bar
• Flow rate:
  • Low pressure: 180 l/min
  • High pressure: 70 l/min

PTO-Pump with cover removed

Motor

• Rated power: 4 kW
• Rotation speed: 1415 rpm
• Voltage: 380 V
• Frequency: 50 Hz
• Type: Three phase asynchronous motor
• Attachment: Star-delta cam switch
• Previous application: Powering a stationary thresher

Motor mount is being positioned on the frame

Control

• Controller: Custom pcb with ESP-32 microcontroller
• Switching power supply: 12 V, 2 A
• VFD: 7.5 kW variable frequency drive
• Servo motor: DS51150-12V 150 kg
• Pressure sensor: Analog 5 V, 0-34.5 bar (500 psi)
• Flow sensor: Size 2”, 5-24 V, 10-200 L/min, 12 Pulses per Liter

Open control cabinet with power supply, custom pcb, VFD and Display

• Regulation
  • Speed Control: Automatically adjusts motor speed to match the water demand using the VFD
  • Pressure Regulation: Maintains consistent pressure output using PID control manipulating the bypass valve with a servo motor
• User Interface
  • Hardware Interface:
    • Start/stop and set target pressure using buttons
    • View sensor data on 7 segment display
  • Web Interface:
    • Control pump remotely
    • View data history
• Smart Control
  • Auto Power Down: Enters power-saving mode during inactivity
  • Dynamic pressure: Reduces Pressure when no water is used

First test with servo controlling the bypass valve