A hydraulic power unit should be specified from the machine duty, not selected only by motor power or tank size. Pressure, flow, actuator speed, duty cycle, control logic and heat generation must be considered as one system. A clear operating description helps prevent an oversized, overheated or poorly controlled unit.
1. Define the actuator and motion
List each cylinder or motor, its bore or displacement, stroke, load, required speed and operating sequence. State whether several actuators move at the same time. This establishes the required flow and how the valve circuit should distribute it.
2. Confirm pressure and flow
Provide the normal working pressure, required maximum pressure and expected flow. The relief setting should protect the system without becoming the normal operating control. If the load varies widely, explain the complete operating cycle rather than supplying only one maximum value.
3. Describe the duty cycle
- Running time per cycle
- Cycles per hour
- Continuous or intermittent operation
- Ambient temperature and ventilation
- Expected start frequency
Duty cycle strongly affects motor selection, reservoir volume, oil temperature and the need for cooling.
4. Specify the electrical supply and control
Confirm voltage, phase and frequency, together with the required control voltage. List sensors, pressure switches, emergency functions and any PLC or remote-control interface. For DC mobile units, also provide battery voltage and available current.
5. Define the hydraulic circuit
State whether the unit is single-acting or double-acting and describe load holding, lowering control, unloading, pressure regulation and emergency operation. Include filtration, return-line requirements and cleanliness expectations where known.
RFQ checklist
- Application and operating sequence
- Pressure, flow and actuator data
- Motor voltage, phase and frequency
- Reservoir orientation and installation envelope
- Valve functions and electrical controls
- Duty cycle, environment and cooling needs
YUYOU Hydraulics can configure the pump, motor, reservoir, manifold and control components around the confirmed working conditions.
