TTPS Operation Circle MPM II Unit IV and V Mill gear box inspection complete overhauling and reassembling of gear box in Unit IV and V HP 803 bowl mills during breakdown of gear box

Charges for draining the oil from mill gear box, cleaning the gear box, worm wheel, worm shaft with neat cloth, arresting of oil leaks and refilling the gear box with old or new oil as directed by the Engineer –in charge, including transportation of material from and to stores and cost of consumables.

Charges for Dismantling of upper skirt assembly, lower skirt assembly, Mechanical face seal assembly, dust guard and blue matching of seal runner, renewal of seal (bronze), air seal, dismantling of Mill bottom cover, upper bearing housing cover, oil seals etc., Complete overhauling, assembling back the lower skirt assembly, scrapper assembly and arresting the oil leakages in the return line and also spillage’s at the rear side of gearbox to prevent Mill fire including cleaning and tapping the threaded holes.

Charges for dismantling the gear coupling bolts, gear coupling (worm shaft only), distance piece, unscrewing the worm shaft extension cover bolts and bearing housing cover bolts, removing the worm shaft extension cover, lowering to ground floor, releasing the worm shaft assembly from its position and assemblies providing back the overhauled worm shaft assembly in the gear box and fitting back the worm shaft extension cover, bolting and tightening the bolts to the required torque level and assembling back the gear coupling bolts, distance piece etc.

Charges for checking the bearing clearance after dismantling the thrust bearing and radial bearing housing covers, removing the bushes, springs etc. thoroughly cleaning the bearing housings and other components inspecting the thrust bearings, resetting the axial clearance by reducing the thickness of shims in the thrust bearing housing cover, providing of new shims and by trial method adjusting the clearance to 0.10 mm to 0.15 mm. Assembling back the thrust and radial bearing housing properly and renewing the gland studs and gland packing in the worm shaft assembly.

Charges for changing the worm shaft thrust bearing after gas heating and releasing the old bearings from the worm shaft, heating the new bearing in oil bath and providing the new bearing in the worm shaft in proper position.

Charges for renewing radial bearing in the worm shaft after gas heating and releasing the old bearing and providing new bearing in the worm shaft after heating the bearing in oil bath.

Charges for lifting the bowl hub, bowl along with the bull ring segments and vertical shaft by hydraulic jacks, clamping the thrust bearing with fixtures and removal of shims and releasing the jacks, checking blue match, radial run out, back lash as directed by the Engineer incharge, including the cost of consumables.

Charges for dismantling the bowl hub cover, removing all studs in output shaft, removing the bed bolts and dowels of gear box and lifting the bowl by about 60mm supporting the bowl with temporary support, removing the reject hopper with tramp iron chute, removing lube oil inlet & output lines and racking out the gear box from the sole plate through rolls and leading to a position away from the mill bay, as direction by Engineer – in –charges. This including transportation of material from and to stores provision of necessary pulling and lifting machineries, slings, consumables etc.., required for the work.

Charges for leading the gear box from mill bay, installing on the sole plate, fixing of dowels and tightening of bed bolts, lowering the bowl on the gear box output shaft after releasing the temporary supports, fixing and tightening the bowl hub cover, dismantling of the scrapper shoe assembly and refixing with correct clearance, attending to correction works in the under bowl bottom plates & liners, re-fixing the reject hopper and connecting the oil lines and commissioning the gear box.

Charge for removing the gear box top cover after removing the bolts, cleaning the top bearing, checking the clearance, renewal of top guide bearing if necessary and refitting the same as direction by engineer in charge. This includes cost of consumables and T&Ps etc..,