Brushless DC motor life expectancy

[hyboxis79]

Can anyone recommend me a way to calculate Mean Time Between Repair (MTBF) of BLDC motor. Is there a way of estimating it without the help of the manufacturer?

The engine specs are:
2 poles 21 winding
inrunner
1:4.4 transmission
76.1 mm length
27.6 mm diameter
15 Ampere
15 volt
max rpm 60k
appreciate anyone's help

 

[davidbeach]

MTBR and MTBF are not the same thing. Motor and engine are not the same thing. Every manufacturer will have (very) different MTBR and MTBF numbers. So, no there won't be much help without contacting the manufacturer.

 

[sreid]

Often the motor life is predicted based on bearing life. At 60 KRPM this is probably the case. Bearing manufacturers have good data on this.

The environmental conditions are key to motor life. Can dust get into the bearings? Is the motor temperature cycled causing differential thermal expansion stresses?

 

[MotorVib]

It is also based on the motor temp, but most of the units that I have worked on the insulation life was the limiting factor unless it was being belted. With that said a brg can sound bad and keep working for a vary long time before it fails. In my years working on motors, people often would say the the brg has failed and when it was taken apart the brg would still be good. There should be a way to grease the brg's and given the motor size I would thin that it will have to be greased every 2 to 6 months based on useage. I am assuming they are ball brg's, rolling brg's will need to be greased more often.

sreid is right the environmental conditions are key to motor life. Dust and durt can kill a motor life by increasing the winding temp and contaminating the brg grease.

The best thing to do is to call the manufacturer and talk to them about it. They will want to know what the room temp, load that you are running and type of service (hours per day running).

Chris

"In this house, we obey the laws of thermodynamics." Homer Simpson