Re-machining on Crusher Shaft

A precision intervention was carried out on a Ø950 mm crusher shaft, specifically targeting the re-machining of the journal over a length of 440 mm. The goal of this operation was to ensure the required geometrical characteristics and surface finish for optimal in-service performance.

The task involved careful grinding of the journal to achieve a surface roughness (Ra) between 0.3 and 0.4 μm, in full compliance with the technical specifications for such large-scale components. This high level of finish is essential to ensure a reliable interface with mounted elements and to minimize premature wear or friction.

This operation is part of a broader quality assurance and reliability approach for critical surfaces, ensuring that machined components meet the mechanical requirements of the equipment.

On-Site Grinding of a Turbine Shaft – Hydroelectric Site

As part of a corrective maintenance operation, on-site grinding was carried out on two cylindrical bearing surfaces of a turbine shaft at a hydroelectric facility. These areas exhibited surface defects that were incompatible with reassembly requirements.

The intervention was performed directly on-site using an abrasive grinding system mounted on a custom support. This method allowed correction of surface irregularities without disassembling the shaft, maintaining its position and axis throughout the process.

Manual alignment using a dial gauge ensured precise positioning of the tool along the shaft axis, guaranteeing consistent and accurate rework. The abrasive process achieved the required surface finish while adhering to the specified dimensional and geometric tolerances.

The operation concluded with a dimensional inspection of the reworked areas, confirming that the shaft was compliant and ready for reuse.

This type of on-site grinding provides an efficient solution for restoring functional surfaces, minimizing downtime and avoiding heavy dismantling operations.

Rehabilitation of a span by orbital machining 

As part of a curative maintenance operation on hydraulic production equipment, an intervention was carried out on a damaged cylindrical bearing, requiring a geometric correction on site.

The operation involved a cross-axis orbital machining machine, allowing direct intervention on the shaft without disassembly of the structure. After establishing a geometrical reference via laser tracker, an unwinding machining was carried out, with a removal of 10 mm at least radius over a length of 450 mm.

A weld was then made on the two chamfers, followed by a finishing machining of diameter Ø200 mm, carried out in a tolerance of 0.10 mm, by controlled pass.

The entire intervention was conducted in a constrained environment, with portable equipment and a high level of accuracy requirements. Dimensional and visual checks were used to validate the compliance of the treated scope.

This type of service illustrates the ability to restore critical functional areas on site, reducing downtime while ensuring the reliability of mechanical assemblies.