Ship Loader Shuttle Investigation

Description of Problem

BMT WBM was commissioned to assist in identifying the cause of excessive resistance in the dual drive system of a ship loader boom conveyor shuttle. During acceleration and deceleration of the shuttle, the drive carriage exhibited excessive deflection and, after only a short period in service, the drive system components had developed undue wear.

The drive system was a similar mechanical system to that designed for a different machine which, over a longer service period, had not exhibited similar problems.

 

What capability BMT WBM was able to offer

With comprehensive experience in heavy machinery and material handling plant BMT WBM undertook an investigation to identify the underlying cause of the increased resistance in the shuttle travel system., BMT WBM was able to determine that the idle redundant drive arrangement was increasing the inertia reflected to the primary drive and, combined with the restraint method adopted in the design, caused a bucking motion of the drive carriage during the acceleration and deceleration of the shuttle. This behaviour resulted in the drive torque arm shearing, failed guide roller bearings and an interference of the drive pinion and encoder pinion mesh. All of which led to accelerated the wear in the pinions.

Following the replacement of the worn components the problem was simply rectified with a change to the control system enabling a load sharing arrangement between the two drives.

 

capability BMT WBM was able to offer