Characteristics

Screw Jacks have different configuration in relation with the application.

Nel caso in cui il carico si muova lungo una retta la configurazione tipica prevede un Martinetto con base ed anello di centraggio.
Per applicazioni con movimento del carico lungo un arco si consiglia l’utilizzo di Martinetti oscillanti. Questi Martinetti hanno le sedi per i perni ricavate direttamente nel corpo.
The units are different because of the Work Screw extending sense respect to the base.
Work Screw move through the gear box. A Nut is integrated with the Worm Gear such that the Worm Gear and Nut rotate together. When the Work Screw is held to prevent rotation, function of load system bonding or with the Jack Anti Rotation device, the Work Screw move linearly through the gear box to move the load.
Work Screw turns moving a Travel Nut. The Work Screw is fixed to the Worm Gear. This cause the load, which is attached to the Travel Nut, to move along the Work Screw.
Based on our long manufacturing experience of special Screw Jacks, we can offer a wide range of equipment, accessories and special solutions.

Work Screw
  • Trapezoidal Work Screw or Ball Screw.
  • Diameter, pitch and end dimensions on request.
  • Anti-Backlash and Anti-Rotation features.
  • Additional guides and mechanical stop.
  • Flexible, fixed, spiral or telescopic protections.
Worm Screw
  • Double or single, short or long extensions.
  • Mechanical protection of unused extension.
  • Special Worm Screw/Gear ratios.
Accessories
  • Complete Jacking system including gear motor reducers, mitre gear boxes and coupling for dual or multiple Jack arrangements.
  • Supports and couplings for direct motor assembly.
  • Screw end clevis (male/female) or top plates.
  • Electric limit switches for stroke control
  • Linear transducer or Encoder for stroke control.
  • Centesimal dial gauge for direct stroke reading.
  • Ratchets, handwheels simple or with gravitational dial gauge.
Operation can be either manual or motorized.
Screw Jack can be used as single units, in dual or multiple arrangements. Motion uniformity is warranted also when operating multiple Jacks of different sizes with uneven load distribution.
  • Check framing has the required strength to carry both the Screw Jack and the load.
  • Check contact surfaces are even.
  • Verify that Worm Screw is not subject to uneven stress due to bad motor and connecting assembly.
  • Before starting the motor, idle runs should be operated by hand to verify the function of the whole assembly and make sure there are no interferences.
Weingrill Screw Jacks require minimum maintenance.

  • Keep Jack lubrified.
  • Screw Jack should be revised every 500 hours of operation to check components wear. Replace lubricant and parts as required.
  • This control shall be more frequent in case of high duty applications.
  • Routinely inspect Work Screw and eventually remove dirt deposits on the thread.
  • When the backlash between Work Screw and Drive Sleeve exceed ¼ of the pitch replace complete Work Screw, Worm and Screw Gear set.
Spare parts or complete replacements units should be kept in stock to avoid possible extended maintenance shut down.
  • Weingrill Screw Jacks are provided with grease nipples and pre-lubrified at our facility.
  • Work Screw lubrication is at user duty.
  • For normal operations check lubrication monthly.
  • For high duty operations check lubrication weekly.
  • For frequent and continuous operations the Screw Jacks should be provided of an automatic lube system
  • Temperature range from –20 to +100°C
    Lubricant: Mineral oil based lithium grease type EP1, viscosity at 40°C=190 cSt.
    Ex. Shell Alvania EP (LF) 1 or equivalent.
  • Contact the Manufacturer for operations at higher temperatures.