EN
Hardened case over a tough core on heavy-duty rack teeth
Core Selling Points
· Large modules for high tangential force and shock.
· 42CrMo or 40Cr: quenched and tempered core for toughness, induction-hardened tooth flanks for wear.
· Spur teeth for simple, robust meshing and no axial thrust.
· Made to drawing or sample, with hardness and material reports.
· Rail car positioners in wagon tipplers at mines, ports and power plants
· Transfer cars and traversers
· Heavy slide gates and bin gates
· Travel drives of heavy carriages
· Replacement racks for older bulk handling equipment
Mining and bulk handling drives combine three loads that racks dislike: high force, shock at start-up and abrasive dust. A rail car positioner, for example, pulls a train of loaded wagons using a rack along the track and pinions on the positioner. The rack tooth sees the full pulling force on every start.
Force decides module. The tangential force on the tooth is Ft = 2T / d, with d = z x m. For a given output torque, a larger pinion lowers the tooth force, and a larger module gives a stronger tooth. Spur teeth are preferred in this duty: no axial thrust on the pinion bearings and no sensitivity to small mounting errors.
Material and heat treatment are chosen for toughness first. A quenched and tempered 42CrMo core takes shock without cracking; induction hardening adds a wear-resistant layer on the flanks. In abrasive conditions, keep the rack accessible for cleaning and use grease that is replenished, not left to collect dust.
| Item | Value |
| Tooth form | Spur, 20 deg |
| Module | M6-M10 standard; larger to drawing |
| Material | 42CrMo, 40Cr, C45 |
| Heat treatment | Quenched and tempered core + induction hardened flanks |
| Accuracy | DIN 8 / DIN 9 (milled) |
| Length | To drawing; joinable sections |
| Reports | Material certificate, hardness report |
| Module m | 6 | 8 | 10 |
| Pitch p, mm | 18.85 | 25.13 | 31.42 |
| Tooth depth 2.25 m, mm | 13.5 | 18.0 | 22.5 |
| Pinion d with 17 teeth, mm | 102 | 136 | 170 |
Tooth force falls as pinion diameter rises: Ft = 2T / (z x m)
· Toughness-first material and heat treatment for shock loads.
· Copy service for worn racks without drawings.
· Racks and pinions supplied together and checked for mesh.
Applicable Industries
Mining and quarrying, ports and bulk terminals, power plant coal handling, steel works, cement plants.
Note: longwall shearer haulage racks are a separate, mining-certified system and are only made to the customer's drawing and approval.
For drawings, samples or a quotation, send us your rack, pinion or gear specification and quantity.
