1. Motor Power Calculation
Formula:
P(kW) = Q(L/min) × P(bar) / (600 × η)
Parameters
- P: Motor power (kW)
- Q: Pump flow (L/min)
- P: System pressure (bar)
- η: Efficiency (normally 0.8~0.9)
Example:
Flow = 20 L/min, Pressure = 100 bar, Efficiency = 0.85
Power ≈ 3.9 kW → Use 4 kW motor
2. Pump Flow Calculation
Formula:
Q(L/min) = V(ml/r) × n(rpm) / 1000
Parameters
- V: Pump displacement (ml/r)
- n: Motor speed (rpm)
Example:
V = 8 ml/r, n = 1450 rpm
Q ≈ 11.6 L/min
3. Cylinder Thrust Calculation
Formula:
Thrust (kgf) = P(bar) × A(cm²) F = P × (π × D²) / 4
Parameters
- D: Cylinder bore (mm)
- P: System pressure (bar)
Example:
Bore D = 50 mm, Pressure = 70 bar
Thrust ≈ 1370 kgf
4. Cylinder Speed Calculation
Formula:
V(m/min) = Q × 10 / A(cm²)
5. Common Matching Recommendations
| Motor Power | Pump Flow Range | Typical Applications |
|---|---|---|
| 0.75 kW | 4~6 L/min | Small machines, clamping |
| 1.5 kW | 8~12 L/min | Light industrial equipment |
| 2.2 kW | 15~20 L/min | Medium machinery |
| 3 kW | 25~30 L/min | Industrial presses |
| 4 kW | 40~60 L/min | Heavy equipment |
| 5.5 kW | 60~80 L/min | Construction machinery |
| 7.5 kW | 80~120 L/min | Large hydraulic systems |