SERVICES
Welding repair
Welding repair can be achieved durably.
Concerning welding repair, Novexa offers its competencies in the following cases :
- Gear teeth breakage, even on high hardness until 60 HRc
- Methodology : Preheating 150°C maximum, regular fissure control through dye penetrant inspection, welding rods 680S, 2222 or 3922, preheating if ARCAIR
Remachining of gear teeth according to our own procedure Novexa, précision 0.1mm
- Breakage or fissures on tires and bearings
- Fealure of ferrules or ground of mill
- All types of fealures or breakages on crown junctions, rims and others...
Our difference does not lie in the welding repair itself but in the added value from gear teeth reprofiling or remachining of tires. Actually our global understanding enables us to intervene, taking into account the entirety of causes and effects.
The precision of these interventions is fundamental for the durability of the equipment.
Welding repair – Case n°1
Situation :
A broken tooth on a kiln crown
- helical gear teeth
- module 30
- width 600 mm
- fissuration in the rim require a dismantling for repair
Appearance of the broken tooth.
The piece represents 85% of the total width.
This could stem from an assembly defect /tightening of the junction. Helical gear teeth are very sensitive to meshing constraints on the edges.
Appearance of the breakage.
A fissure has been detected on the opposite pitch.
Before any intervention, a lifting of the material by ARC AIR needs to be done in order to clean the area and avoid occurrence of fissures.
Welding repair by a welding bead.
NOVEXA defines the type of welding rod. We dispose at least of one Novexa welder in every team (the other one might be a local welder).
Tooth in the making.
The welding need to be carried out regularly, pre-heating must be permanent at 130 / 150 °C.
The tooth is completely rebuilt and ready for machining
The cutting side needs to be adjusted in order to obtain :
- a load distribution centered on 80% of the tooth.
- a profile and pitch of less than 0,07 mm.
Phase of pre-heating and reprofiling of the welded tooth.
Welding process.
Our workers respect the defined procedures scrupulously .During the entire process, security procedures are always carefully respected. A security meeting is arranged by the responsible Novexa manager at the start of every job.
The tooth flank is cleaned after the procedure.
The cutting sides are controlled and validated via a template.
This picture has been taken during a repair process of a second unattainable fissure, after dismantling of half of the crown.
Appearance of gear shortly after relocation.
The sides, the active flanks and retro have been re-machined on-site.
Visionée : Etape 1
1
2
3
4
5
6
7
8
9
10
Welding repair – Case n°2
Intervention on a kiln roller.
Fissuration between 2 holes of foundry / smelting ?.
Deformation of the welding seam by par procédé ARC AIR.
View of the area after teeth grinding process and before the start of the welding process.
Maintaining the temperature at 150°C.
Chiseling of the welded area.
Polishing of the surface for final condition.
Visionée : Etape 1
1
2
3
4
5
6
7
Welding repair – Case n°3
An orientation ring with a tapered interlock has come back to the premises.
Reason : transversal fissuration on 1 tapered interlock.
NOVEXA has confirmed the feasability of the reparation.
Opening of the fissure after flanging of the ring.
Machining stage and pre-heating to 140°C.
Welding stage with a welding rod, chosen by NOVEXA (and consulting CASTOLIN).
Process :
- welding of the fissure
- reprise of the main bore
- drilling of tapered interlock.
Welding completed.
A fissuration control via magnetoscopy is carried out after machining.
Rerun of the main bore and drilling of the tapered interlock. Tolerance levels are inferior to 0,03 mm.
Result after reparation and assembly.
The ring has been repaired in 2 days.
The supply of a new one would have been taken 2 months (production halt).
Visionée : Etape 1
1
2
3
4
5
6
Novexa has always been an expert in managing wear speed. As a privileged partner in the industry, Novexa disposes of a long record of interventions regarding wear of gear, reprofiling, consulting and audit.
As of today, Novexa has developed its service range even further : our unique know-how applies to the wear of tires, alignment control measures and linked services ( bearing scrapping, welding repair etc.) as well.
SERVICES