Helical Gear teeth temperature measurement

[SMKRe]

In high speed spur and helical gearboxes lubricated using oil-jet lubrication,
How to estimate the gear teeth temperature accurately? What are methods and instruments to be used? Is it possible to measure the teeth temperature while gearbox is running or It must be stopped to measure the temperature?
Please suggest methods for measuring temperatures while gearbox running and also after stopping?

 

[TugboatEng]

In cases I have seen the temperature of the oil leaving the gears is measured. You would need to incorporate some type of baffle to catch the oil thrown from the heat and concentrate it near the sensor.

 

[SMKRe]

Dear TugboatEng,
I need to measure both gear teeth temperature and mesh oil exit temperature. What will be the temperature difference between these two? In my case oil inlet temperature is 45 degree Celsius (high power and high speed gearboxes- 35 MW and 110 m/s PLV).
Could you please suggest, Some other methods to measure gear teeth temperature.

Oil-jet lubrication directed towards out-mesh or radial to the center of the gears to cool the gears.
Coming to mesh oil temperature measurement, suggest some best ways for collection of mesh oil from gears. Where I need to place the collector/baffle to collect the mesh oil. (pinion bearing oil should not mix)
or else
Where (Near to the gear mesh) can I mount RTD to measure the mesh oil exit temperature?

Please Clarify

 

[mfgenggear]

to my knowledge there is no direct method to measure the gear teeth temperature. while running. but there is measuring the oil temperature. it would be possible to measure the temperature of the housing with electrical sensors. just like measuring the coolant in an automobile.

 

[SMKRe]

Which is the best location to mount RTDs in gearbox to measure mesh oil exit temperature? I am placing it near the Pinion side drive end and non-drive end, where axial mesh flow will come into contact with RTDs. is there any chance of bearing oil coming into contact?

Could any body suggest where the RTDs should be mounted to measure only mesh oil exit temperature.

 

[SMKRe]

Oil inlet temperature to Gear mesh is around 45 deg Celsius. I would like to measure Gear/pinion tooth temperatures using infrared gun after gearbox reaching standstill with lubricating oil also stopped. Will the infrared gun give correct tooth temperature values? Is this method of measuring standstill gear system tooth temperature (instead of running gear system) acceptable in industries?

What could the temperature difference of tooth while in running and after stopping the gearbox?

Please suggest.

 

[romke]

Why are you interested in the teeth temperature? Long before the teeth temperature causes problems to the teeth, the oil temperature will reach a point that viscosity might be too low to lubricate the gears properly and/or oxidation will shorten the time the lubricant can be used.

A reasonably accurate measurement of the bulk oil temperature at startup and the way it changes when running the gears under load usually can indicate whether something needs to be changed in the present setup.

A changeover from a simple mineral oil to a synthetic oil (PAO, PAG)may result in a lower oil operating temperature if the oil temperature is thought to be excessive.