Metric Trapezoidal Screw Jacks - Notes

  1. The recommended maximum speed is 1,800 rpm providing the recommended horsepower and temperature are not exceeded.
  2. 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.
  3. 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.
  4. Overload capacity of the Trapezoidal Screw Jack is as follows: 10% for dynamic loads, 30% for static loads.
  5. 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.
  6. 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.
  7. Accessories such as boots, limit switches, top plates and clevises are available.
  8. Catalog dimensions are representative only and are subject to change without notice. For construction, use only certified prints.
  9. Units are not to be used as personnel support or movement.
  10. End-of-travel stops are not provided.
  11. Starting torque is100% greater than torque shown.
  12. kW per jack = Torque to raise 1 Kn (N·m) × Number of kN to be raised × rpm
  13. No load torque need only be added if operating under 25% rated load.
Figure 1