Blackstone completed a comprehensive overhaul of a RENK pelletizer gearbox after significant bearing and shaft damage resulting from high unit thrust. The project required advanced mechanical expertise, precision machining, and coordinated execution to restore the gearbox to reliable operating condition within a demanding schedule.

Fig 1. T2 Output Shaft    |   Fig 2. T1 Output Shaft

• Replaced 38 bearings across six shafts using new OEM-specified components

• Repaired damaged thrust bearing fits on the T2 output shaft

• Restored the T2 planetary carrier bearing fit to original specifications

• Completed full inspection, dimensional verification, and reassembly

• Executed precision machining to correct shaft and housing tolerances

Incoming & Disassembly 

• Identifying and qualifying specialized grinding vendors capable of handling large-diameter shafts with tight tolerances

• Rapid sourcing of specialized materials from the U.S. for custom spacer fabrication

• Safe handling and installation of large-diameter shafts and bearings

• Performing precision machining on the damaged T2 shaft to achieve correct thrust bearing fit

Assembly 

Despite complex mechanical damage and logistical constraints, the gearbox was returned to service on an expedited timeline. Through coordinated vendor management, extended work hours, and precision repair execution, Blackstone successfully resolved bearing failures and dimensional issues.

The customer benefited from minimized downtime, restored gearbox reliability, and renewed operational confidence in a critical pelletizer asset.