Rehabilitation of a A2800 Gear Drive Unit
VAKOMA make every effort to provide tailored solutions to relevant drive and gear problems.
Unquestionably, the Type A2800 mill gear drive with Novikov teeth is one of these problematic gear units (in part, upgrading has already been made with modest success). For torque splitting and torsion shafts, in conjunction with perfectly adjusting the teeth on this gear drive, a task almost impractical to solve, VAKOMA have devised a tailored solution technology.
This technology comprises several specific steps of work. It starts by precisely reconditioning the existing gearcase on site, and installing new Vakoma gears with case-hardened and ground involute teeth is the final step. As the technology involves re-boring of the existing gearcase VAKOMA have designed, built and tested a dedicated job-to-job machine tool.
Both this machine tool which serves to correct misalignment of bore centres in the gearcases, and the VAKOMA® gears allow long-time and trouble-free operation to be achieved for the gear drive units and, hence, the cement mills.
Following the rehabilitation, the A2800 gearcase would house one complete set of gears (shaft, gear, pinion) less. Yet, the torque required will be transmitted without deficiency due to use of advanced materials, with less mass moved, entailing durable energy and oil savings
Time needed for rehabilitation: 10 to 20 days
Unload the received Vakoma gears with hardened and ground involute teeth.
Remove the bearing caps of the existing A2800 gearcase.
Gauge the casing and the bearing bores by means of a high-accuracy 3D coordinate gauge (laser tracker).
Unpack the Vakoma rehabilitating unit and position it in the 'line' of bores.
Position the rehab unit in the mid 'line' of bores.
Mount the bearing caps and fine-position the rehab unit. .
Use the Vakoma rehabilitation unit to re-machine the bearing bores.
Head of Job-to-Job Machining to supervise machining operations.
Position the Vakoma rehab unit in the outer 'line' of bores and use the laser tracker gauge to verify the accurate physical location and alignment. (The 'line' of bores for machining is chosen following prior gauging. Only one outer 'line' of bores will be needed; the other one will remain clear).
Install the new Vakoma sets of gears in the rehabilitated 'lines' of bores.
Vakoma Sets of gears installed will have case-hardened and ground teeth.
Adjust the teeth in mesh and use blueing ink to check the contact pattern.
Connect the new oil pipes.
Establish connection to the new oil supply system.
Mount the output-end clutch.
Mount the drive clutch.
Monitor the key parameters and measuring points during trial operation.
Monitor the oil supply system and the oil temperature during trial operation.
Check oil supply in the gear drive unit during trial operation.
Ready-to-operate Type A2800 gear drive unit rehabilitated by Vakoma GmbH with 'lines' of bores remachined to a high accuracy so as to achieve the best possible physical shaft location and a long service life. Equipped with case-hardened and ground involute teeth and a new oil supply system.