Straddle carriers based on new technology

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Client
Liebherr Container Cranes, Ireland
Completed
2013 - ongoing
Problem
Bearings of straddle carriers are not reliable enough
Solution
Development of bespoke bearings meeting all requirements

 

Straddle carriers based on new technology

The practice
Straddle carriers suspensions use wheels connected to kingpins for their eight or ten steerable wheels. The kingpins are supported by top bearings. Traditionally roller bearings were used for this purpose, however, this kind of bearing is not very well suited for the application. Life times are relatively short and inconsistent. Replacement of failing bearings is an extensive operation taking a carrier out of the operation for a long time.

Risks and consequences
With a broken king pin top bearing, the carrier needs to be taken out of service and brought in for repairs, both carrying significant costs. When a broken bearing is not detected early enough it can lead to extensive and expensive collateral damage to the expensive kingpins and surrounding parts. Condition monitoring of these bearing up to now has not been successful, they are intact ... until they fail.

The solution
For the top bearings a whole new concept has been made, in which the horizontal and vertical loads are accommodated separately. The metal parts are made out of stainless steel and are combined with D-glide sliding surfaces. The design is compact and can be fitted into existing carriers without modifications.

The result
The new bearings are durable and maintenance free. The weakest link in the suspension system has been eliminated increasing the reliability to the highest level possible with today’s technology. Down time is reduced to the minimum as is the risk of costly repair, with all consequential positive financial and operational advantages.

Links
http://www.liebherr.com/MCP/en-GB/products_mcp.wfw/id-19162-0/measure-metric
https://en.wikipedia.org/wiki/Straddle_carrier