Automation Application – Loading Dock’s Corrosion Problem – Solved by LM76!

E. Longmeadow, MA – Linear Motion Application – Automation – 

The Problem –

An LM76 customer is a manufacturer of loading dock ramps. These automation systems are installed in every state and experience all climates and conditions. Each dock section employs a 1″ shaft and linear bearings for length adjustment. Delivery trucks are side-loaded so the platform is adjusted outward to meet the truck body so loaders/unloaders have a safe walkway between building and truck. If the ramp cannot be properly adjusted because its rusted, frozen solid, gaps between the loading dock and the truck body become fall-through hazards for workers.

Why is this system failing? In many northern facilities, accumulated snow and ice are sprayed down with glycol and then salt. The system originally used Rc60, 1060 steel shafting and standard steel shelled, 52 100 linear ball bearings. A bad choice for such a tough, corrosive environment. Quickly, these systems were rendered useless, frozen in place, and hazardous.

The Answer –

LM76 was called to review the situation and asked to come up with a recommendation. Given that their customers had a very large installed base, the cost of changing out the design format with a new design was out of the question. Thus, LM76 had to come up with the best possible fix that would allow for a fast and uncomplicated field retrofit package.

First, LM76 changed out the original steel shaft with a 44c stainless steel shaft. Although the 440c is more corrosive resistant than the steel, it has carbon introduced into its chemistry so that it can be case hardened (required for linear bearings). For additional hardness (fromRc60 to Rc78) and superlative corrosion resistance we coated the shaft with a special thin dense chrome. For a direct plug-in bearing LM76 chose a 440c stainless steel linear ball bearing with special scraper seals.

About LM76

Founded in 1976, LM76 has been a leading designer/manufacturer of linear bearings, slides and linear motion systems. LM76 is renowned for its industry leading Minuteman PTFE Composite linear bearings. LM76 is a leading supplier of precision linear shafting: RC60, 300 Series Stainless Steel, and ceramic-coated aluminum shafting. LM76 also offers several FDA/USDA compliant linear bearings and slides for the food processing, pharmaceutical, medical, and packaging industries.

For additional information contact Mike Quinn at: LM76, 140 Industrial Dr., E. Longmeadow, MA 01028; Telephone: , Fax: 413-525-3735 or E-Mail: mquinn@lm76.com or visit the website at http://www.lm76.com