Lubrication Management ofRotating Element Bearings

SAIEE RMS Technical Forum

Mario Kuisis/2017-02-21

Agenda▌ Causes of failure

▌ Typical lubrication issues

▌ Lubrication management options

▌ Taking control

▌ Case study

Causes of Motor and Bearing Failure

Causes of Motor and Bearing Failure

Bearing lubrication issues

• Under lubrication

• Over lubrication

• Wrong lubricant

• Contamination

• Overheating

• Aged lubricant

Lubrication Management

Options

• Sealed bearings – no maintenance

• Manual greasing – fixed time interval, volume managed

• Manual greasing – fixed service interval, volume managed

• Automatic greasing – fixed time interval and volume

• Manual greasing - on demand

• Vibration

• Temperature

• Ultrasound

Naturally occurring ultrasound

What is Ultrasound?

Same as ultrasonic

sound

Characteristics of Ultrasound

• Readily travels through gases, solids and liquids

• Obeys the rules of reflection, refraction and diffraction

• Low diffraction in air

• Pronounced directional properties

• Low energy

• Attenuates rapidly

• Produced in great intensity by any friction event

All bearings produce ultrasound

Mode of use

An experienced

ultrasound

inspector

Possible causes of high ultrasound

• Worn bearing

• Under lubrication

• Over lubrication

• Degraded lubricant

In our experience - the most common enemy of bearings in SA

• Too much grease has caused the bearing

to explode. The seal has been pushed out

and the balls have dropped out through

the gap.

• Stopped production for 4 hours

The solution

Acoustic

lubrication

Monitor ultrasound whilst greasing

Bearing in need of grease

Bearing not needing grease

From under to over lubrication

How is it done?

• Lubrication adaptors for

use with purpose built

ultrasonic detectors

• Monitor and quantify the

ultrasound whilst greasing

Acoustic lubrication

Eliminate the

guesswork

• Listen to ultrasound and measure ultrasound dBµV level

• Apply half stroke of grease

• Wait 15 to 30 seconds

• Listen to ultrasound whilst checking the ultrasound dBµV

• If the ultrasound reduces, apply more grease

• As soon as the level of ultrasound goes up, STOP greasing

• If it went up on the first stroke, STOP immediately

Trend chart – good bearing in need of grease

Case study

Results of a

successful

acoustic lubrication

management

programme

• Friction monitored by ultrasound level

• Lubricate when ultrasound level exceeds threshold

• Grease volume managed by ultrasound

• Detect lubricant that is contaminated, aged, over heated

and degraded by incompatible mixing

Bearing life

Grease consumption

Thank youwww.pragmaworld.net

www.martec.co.za