Vibration causing coupling failures – Causes and solutions

Vibration causes coupling failure for a number of different reasons.

Couplings provide a vital function of mechanical power transmission from engine source to equipment.

Traditional coupling technology is broken into 2 sections, high speed low angular misalignment or lower speed and higher angular misalignment.

Traditional high speed coupling need precise installation.

High speed coupling like jaw couplings, elastomeric coupling, grid couplings/spring couplings, tire couplings have a very small amount of angular misalignment, this misalignment is less than 1°. The speed at which the couplings run in usually in excess of 4500 rpm, this means with such small degrees of misalignment, installation is critical and any variations means these couplings work out of their intended capacity.

Elastomeric couplings need insert replacement as vibration increases.

This means couplings become out of phase and for these couplings, increased wear of their internal components such as spider inserts, springs or elastomeric. With this increased wear comes increased vibration since these inserts are meant to absorb vibration. This then means these inserts need to be replaced otherwise the vibration gets worse.

If the coupling needs to be used at more than 1 degree then what are the options.

The usual option are universal joints but that creates its only issues.

  1. It cant run at the high speeds that elastomeric and jaw couplings can be used at
  2. Internal bearings need constant greasing  and when worn replacement.
  3. No ability to absorb vibration, risks damage to equipment.

Universal joint while well know have no ability to absorb vibration themselves without other equipment to absorb it (slip yokes is an example)

Universal joints cant run at high speeds without issues due to heat buildup

Universal joints were designed to be a lower speed application not to be used in the high speed equipment like we have today. Conveyor belts and other industrial equipment is now in use 24/7 and with that “always on” means that the bearings or block and pin that allow the universal joint to be flexible need to be constantly greased as otherwise the equipment will fail due to the heat buildup.

Greasing universal joints every 8 hours

Some applications that universal joints are used in like agriculture, the manufacturers tell the end use to grease every 8 hours or if they use the more expensive needle bearings every 250 hours, so either daily or monthly. Can you stop your equipment daily to be greased? Use a number of universal joint or they are in hard to reach places, so how long each day or month are you wasting on greasing universal joints?

Forget the greasing, how much is it costing in downtime and labor costs to replace failed/failing bearings?

A universal joint, a block and pin universal joint are cheap but without regular maintenance they fail so constant greasing is what’s required. Now what happens when its time for the bearings/block and pin to replaced as they are failing or they have failed? When the bearing cross in a universal joint becomes worn, vibration also increases.

Replacement parts are cheap but the lost production time and labor to replace them is not. A worker replacing these parts per hour is costing you $50 plus the lost production time makes it more like $100 per hour, more in industries like mining and then the parts.

So that cheap $40 universal joint is costing you $420 per year based on it needing to be serviced 4 times per year, with replacement parts and that’s not including the cost if it needs to be replaced.

Now put that same universal joint in a hard to reach place, that doubles the cost per year. Still think a $40 universal joint is cheap if its costing you $840 per year?

How many universal joints are in your equipment? The bill adds up, quick.

What Twin Spring Coupling does differently

No 1 We don’t use spider inserts, grid springs, bearings, we use one large central ball bearing to allow the coupling to pivot like that or a universal joint

No 2 The dual spring action absorbs vibration much like the elastomeric insert in traditional couplings

No 3 The springs allow the coupling to be flexible like a universal joint

No 4 No internal bearings means no heat build up and failed bearings due to lack of grease

One coupling that can replace multiple traditional couplings, makes it a cheaper alternative than buying and having to install multiple different coupling types, each with their own unique installation methods.

The cost saving of maintenance and lost productivity make Twin Spring Coupling the only choice when replacing couplings or designing equipment.



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