Injector Bearing White Paper

Here is something you don’t get to see every day. We dissected an injector bearing off of a Hydra Rig Injector model 680.  The engineer who did the failure analysis brought to light some things we expected to see, like uneven load. But, he also uncovered some consistent findings that we think are DETRIMENTAL to the life of these injector chains and bearings.  See below.

Pictured is the inner race of sample bearing one. Notice wear patterns and uneven load that is placed on these bearings.  The title picture is the outer race of this same bearing. The uneven load these bearings experience is something that is just unavoidable during operations.  (unless, you bring your injector in for a retro fit by XS Performance!)

Take Minute and review the notes below from the bearing failure inspection.

Bearing # 1

  • Outer ring – uneven loading and skid marks on the outer ring raceway; minor spalling or corrosion on the raceway.
  • Inner ring – uneven loading and skid marks on the outer ring raceway; minor spalling or corrosion on the raceway.
  • Rollers – minor spalling and skid marks on roller OD
  • Seals – did not seal out the contaminants. Need seal lip improvement
  • Grease – more like brown-muddy liquid.


Bearing # 2

  • Outer ring – more uneven loading compared to bearing # 1. One row of roller takes more load than the other.
  • Inner ring – on one side there is very little wear mark on the inner ring OD.
  • Seals – did not seal out the contaminants. Need improvement.
  • Grease – more like muddy slurry.


Attention: I know we like to keep our equipment clean, and looking good for customers rolling out onto their location.  Even the OEM suggest washing chains of debris for a regular/routine P.M.   Can we be over doing it?  Pressure washing bearings has never made any sense to me. But it seems to be a common practice within the industry.

When I read the engineer’s review of the condition of the grease I laughed out loud! I am convinced that if we take some more time and attention during machine cleaning, that the life of these bearings could be extended. Keep the pressure washer away from the bearings!!!!! Is removing bearings before cleaning and installing after cleaning too tall of an order? Its up to you to decide.

Final thought on the review, Skidding on outer races. This is an easy one to look for while injector is in shop or ground level. Skidding = Too fast + not enough load.  When this happens through the traction zone, the inner and out races and not rotating. Instead, the bearing is sliding through the work zone instead of rotating.

If you are in need of injector bearings, chain parts, or a complete injector chain assembly give us a call.  Servicing all US shale plays.


Extreme Shale Performance LLC
Elmira NY, Odessa TX, Washington PA
Phone: 814-688-7956