Manual Screw Jacks, when to use?

hand wheel screw jack

As you know, Screw Jack can be both Electric Driven and Manual operated.  When you manually operated screw jacks, you can use hand wheel or hand crank. So when to use hand wheel screw jack?

  • In case of power failure, screw jacks can be moved manually via a handwheel. To do this, one input shaft shall be available on the screw jack for the connection of the handwheel. If a brake motor is used, the brake shall be un-clamped firstly, so to allow for movement.
  • Light load, low duty cycle, low-speed application.
  •  Intermittent positioning applications

Our standard jacks use Trapezoidal screw and have self-locking function which is very safe for manually operated by hand. We have different models for your selection, our SWL machine screw jack is extremely popular for this application.

You can also use digital position indicators if you need more precise position display. It can measure the rotations of the input shaft and display the corresponding position in the digital counter window. The display value per input shaft revolution is variable and is achieved through a series of gear reductions configured to accommodate different worm gear screw jack ratios, screw pitch, and travel length.

How to choose handwheel for manual screw jack?

manual screw jacks
Some people select any handwheel that rotates without careful consideration, but whether the design is right or wrong makes a significant difference in practical use. While the output of an ordinary person, which can be generated for 10 minutes or more, is said to be 1/4 horsepower, the operation cannot be maintained unless the handwheel operating force is no more than 50 N.

The handwheel (handle)operating force(P)is calculated as follows:

P= input shaft torque/Handwheel radius.

Select a handwheel ensuring P=5oN or less

Our hand wheel screw jacks advantages

  • Easy installation to existing actuators. All hand wheels are bored, keyed, and set-screw drilled to the proper dimensions.
  • Revolving handle design for rotational ease.
  • Recessed hub and spoke design.
  • Cast iron material with chrome plating

The table in our screw jack system necessories page presents dimensional information for our Hand Wheels. To properly select the best hand wheel for your application, please review the provided information, or contact [email protected]