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A recycler was experiencing regular failures of a mounted bearing unit on an optical sorting conveyor. In the three months after installation of the machine, a total of 5 bearing failures were recorded. An NSK application engineer examined the application and determined that vibration and lubrication issues were causing the bearing to fail prematurely. NSK recommended using SNN Plummer Blocks combined with NSKHPS Spherical Roller Bearings.

Key Facts

  • Optical sorting machine
  • Mounted units failing prematurely
  • Vibration causing grub screws to loosen and shaft to spin on bearing inner ring
  • Heat generation caused by no lubrication escape path.
  • NSK solution: SNN plummer blocks with NSKHPS Spherical Roller Bearings
  • Elimination of bearing failures
  • Significant reduction in downtime and maintenance costs
  • Optical Sorter Conveyor
  • NSK Plummer Block SNN series

Value Proposals

  • NSK Application Engineering performed an Application Review following a Failed Bearing Analysis
  • It was determined that vibration  had caused the grub screws to loosen, resulting in the shaft spinning in the bearing inner ring
  • It was also determined that the type of mounted unit allowed for no grease escape path, which caused excessive grease build up resulting in high heat generation
  • NSK recommended HPS Spherical Roller Bearings mounted on adapter sleeves in an SNN plummer block housing.
  • The adapter sleeve locking method means that the bearing cannot come loose on the shaft even with vibration
  • NSK SNN plummer blocks provided a grease escape hole as standard, allowing excessive grease build up is avoided
  • No failures have been recorded since suggested recommendations were implemented

Product Features

  • Equipped with 2 lubrication and 1 draining hole
  • Solid base corners for locating pins
  • Square shape and center marks
  • Easy assembly and alignment with low maintenance costs
  • High rigidity-minimizing deformation of the bearing seat
  • Comprehensive range of sealing & arrangements to match all needs
  • Excellent heat transfer
  • Housing can be used with both double row self-aligning ball bearings or double row spherical roller bearings

Cost Saving Breakdown

Before Cost p.a. NSK Solution Cost p.a.
20 bearings annual $8,998 4 bearings annual $900
10 breakdowns annual, 2 hours per breakdown, $2,250 per hour cost $45,000 No breakdowns $0
Fitting and inspection $3,000 Initial fitting costs $599
No Training $0 Training and install supervision $900
Total Costs $56,998 $2,399