Introducing New Screw Jack Design and Application Guide
Screw jacks are low duty mechanical linear motion devices used in lifting and positioning systems. They are often combined with other connecting and drive components to create a multi jack lifting system. However, because every requirement is very different, selection can sometimes be difficult.
So, to help get you started on organizing the characteristics that need to be considered, DieQua has created a new screw jack design and application guide to highlight the available options and provide advice on how to design your system.
Screw jacks are typically rated for their static capacity. This means how much force the screw jack can hold. There are several characteristics that can limit the amount of force allowed. In it’s static state the first consideration would be the screw length.
In a compression load, there are forces exerted on the screw as well as the jack body axial bearings. The longer the screw length, the higher the possibility that the screw could buckle. Hence the term “buckling force”. This could limit the available capacity.
Other limitations on lift capacity have to do with the duty cycle. The faster or more often the load is moved, the lower the dynamic capacity of the screw jack. Because there are high frictional forces, the life reduces or capacities are de-rated as cycles increase. More detail about this is highlighted in the guide.
The majority of lifting applications use a combination of either two or four jacks that share the overall load. This balances the load and allows the use of smaller jacks. The systems can get a little more complicated, however, as the multiple jacks need to be connected so that a single power source can be used to actuate them.
The application guide provides various application examples to give you some ideas on how the jacks might be oriented. While the examples may not be precisely relevant to your industry the basic configuration concepts are highly applicable to other applications.
When designing a system there are many connecting and safety options that are either necessary or can be incorporated to enhance operation. The guide provides several checklists to assure all the elements required in the specification are considered.
Screw jacks with capacities from 1/2 ton to 100 ton are highlighted in the guide. Two versions, a “Standing” model, where the screw travels through the jack body, and a “Rotating” version, where a nut travels the length of the spindle, are both discussed along with the appropriate options and auxiliary components.
While the guide is a good start and will provide you with the application characteristics that need specifying, it is still best to discuss with your DieQua representative your overall goals. Allowing us to help you move your design in the right direction will simplify the process and assure that you create a reliable and cost effective system.
Did you know that DieQua publishes a monthly email newsletter that features interesting articles just like this one?
Our newsletter was designed to be a little different than other manufacturer's newsletters that are primarily product centric. While products and services available from DieQua are highlighted, other elements revolve around the personal and professional development of the design engineer.
To receive this newsletter, please visit the registration page and fill out your information.