Coupling Inspection Guide for Double-Girder Cranes

Couplings play a vital role in connecting drive and driven shafts, efficiently transmitting torque while often providing vibration damping in heavy-load applications. These crucial components consist of two halves, each mounted to a respective shaft, forming the critical link between power sources and working mechanisms.

1. Common Coupling Types in Crane Systems

Double-girder cranes primarily use flexible pin couplings for their excellent torque transmission capabilities. However, these components require frequent inspection as they represent one of the crane's most vulnerable parts.

2. Critical Inspection Standards

1. Precision Measurement Verification
   • Ensure all dimensions remain within manufacturer specifications using calibrated instruments
   • Immediately replace couplings with excessively worn bolt holes that exceed repairable limits
2. Gear Tooth Wear Evaluation
   • Retire couplings demonstrating 15-20% reduction in original tooth thickness
   • Discard units showing visible fractures or missing teeth to avoid operational hazards
3. Flexible Component Analysis
   • Examine rubber buffers in pin-type couplings for uneven wear
   • Pay special attention to gear tooth conditions in gear-type couplings, particularly in hoisting assemblies

3. Effective Maintenance Procedures

• For pin couplings:
  Promptly replace deteriorated rubber elements or leather pads
  Address vibration issues caused by pin/hole deformation by:
  ∙ Rotating the flange 90 degrees to create new mounting holes
  ∙ Installing new standard pins (never modifying existing holes)
• For gear couplings:
  Conduct monthly backlash measurements
  Apply specialized high-viscosity lubricant every quarter

4.Operational Benefits

Proper coupling maintenance delivers:
✔ 40% reduction in unexpected breakdowns
✔ Extended drivetrain component lifespan
✔ Prevention of dangerous load oscillations