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How to prolong the lifespan of your VSI Crusher Bearings

To ensure prolonged lifespan of your VSI crusher bearings, regular lubrication with the correct grease volume and grease type is essential. All bearing cartridges are designed with a bottom bearing to withstand V-Belt tension, a top bearing to absorb the rotor centrifugal forces and counter V-Belt tension, and a top grease labyrinth to purge foreign material and prevent any dirt ingress into the bearing cartridge.

The bearing cartridge has three (3) grease ports, one for the bottom bearing, one for the top bearing and one to service the labyrinth. Both bottom and top bearings require 10g’s of grease per 8hr shift. The labyrinth requires 50g’s of grease per 8hr shift. To get an idea of how much 10g for the bearings and 50g for the labyrinth is, see the images of grease in a matchbox below.

10 Grams of grease

50 Grams of grease

When using manual lubrication (hand / foot pump) use only Shell Gadus S2-V100-3 or equivalent. This grease has an ISO100 base oil for lubrication, but a thick soap base (NGLI 3). This means the grease base oil is thin to prevent excessive heat, but the grease is also very sticky and will not drip out of the vertical bearings under normal operating temperatures.

Bearing cartridge repair tips:

When repairing failed bearing cartridges, pay special attention to the following:

  • Ensure the bearing cartridge housing and shaft is measured and journal tolerances are within the specified limits
  • Lubricate new bearings to one third (1/3) of the available free space
  • Purge the grease galleries to ensure no blockages exist
  • Use a bearing heater to heat the bearings during assembly – never use a hammer to seat bearings
  • Measure the shaft end float once fully assembled
  • Check that the Labyrinth grease line is piped correctly and not feeding excess grease to a bearing.

Typical causes of bearing cartridge failures:

  • Bearing over greasing causing excessive internal heat
  • Bearing under greasing causing premature bearing wear
  • Labyrinth under greasing allowing dirt ingress into the top bearing
  • Worn / missing labyrinth protection ring (mounted to the rotor underside)
  • Excessive V-Belt tension causing bearing over load
  • Incorrect shaft and cartridge journal tolerances causing bearing overload
  • Inferior bearings used