Metric Trapezoidal Screw Jacks Quick Reference
|MODEL||Gear Ratio||Capacity (kN)||Lifting Screw Dia.(mm)||Screw Lead (mm)||Root Dia. (mm)||Raise for One Turn of Worm (mm)||Max Input Torque (N·m)||Max Input (kW)||Max Worm Speed at Rated Load (rpm)||Max Load at 1,425 rpm (kN)||Torque to Raise 1 kN (N·m)||No Load Torque (N·m)|
- The recommended maximum speed is 1,800 rpm providing the recommended horsepower and temperature are not exceeded.
- Input torque is shown as torque to lift one kN of load. Starting torque is 100% greater than torque shown. For loads less than 25% of rated loads add tare drag torque.
- Maximum allowable power ratings are based on a 25% duty cycle. For operation at higher duty cycles or repeated use over any segment of the total travel, temperature must be monitored and remain less than 95°C.
- Overload capacity of the Trapezoidal Screw Jack is as follows: 10% for dynamic loads, 30% for static loads.
- Trapezoidal Screw Jacks having gear ratios between 20:1 and 32:1, are self-locking and will hold loads without backdriving in the absence of vibrations. All other ratios may require a brake to prevent backdriving.
- All units are suitable for intermittent operation providing that the housing temperature including ambient is not lower than -30°C. or higher than +95°C. Factory supplied grease in standard units will operate in this range. For higher or lower operating temperature ranges consult Nook Industries.
- Accessories such as boots, limit switches, top plates and clevises are available.
- Catalog dimensions are representative only and are subject to change without notice. For construction, use only certified prints.
- Units are not to be used as personnel support or movement.
- End-of-travel stops are not provided.
- Starting torque is100% greater than torque shown.
- No load torque need only be added if operating under 25% rated load.
|kW per jack =||Torque to raise 1 Kn (N·m) × Number of kN to be raised × rpm|