Tuesday, February 27, 2024 3:23:08 PM

Fixed Displacement Gear Pump Failure Mode

3 years ago
#38 Quote
I have a customer who has a fixed displacement gear pump that is bypassing about 2-3 gpm under load. I recommended replacing the pump but their solution was to increase rpm to get to the required flow under load. My concern is the heat generation and eventual failure of the pump.

Will the pump wear faster now the speed is increase? What is the failure mode for a gear pump?
3 years ago
#39 Quote
This begs a couple of questions. What is the pump displacement?  Without this, we do not know what the percentage loss is.
A 60 gpm "efficient" piston pump will have have 3 gpm (5%) heading out the case drain when it is new.
If the pump is worn, then increasing the rpm is an expensive short term fix. The additional lost flow at pressure will take more fuel of kW's and damage the fluid.  Existing contamination will cause wear and the need to increase the rpm even more.
2 months ago
#68 Quote
Have you tried using a peristaltic pump??
2 weeks ago
#72 Quote
What is the specs of the pump motor assembly?
if it's a low flow pump and its dumping oil back to suction under load, i don't think increase in RPM will help as the load will remain same.
replacing a pump/repair the existing one would be a better option.
2 weeks ago
#74 Quote
Hi Kamlesh -  Dan Helgerson answered a similar question a while back, he stated “This begs a couple of questions. What is the pump displacement?  Without this, we do not know what the percentage loss is. A 60 gpm "efficient" piston pump will have have 3 gpm (5%) heading out the case drain when it is new. If the pump is worn, then increasing the rpm is an expensive short term fix. The additional lost flow at pressure will take more fuel of kW's and damage the fluid.  Existing contamination will cause wear and the need to increase the rpm even more”.  

Another suggestion was to use a peristaltic pump.  Those are generally used when you don't want a possibility of contaminants in the fluid and they are commonly used in the medical industry as an accurate metering pump but they are limited as to their maximum pressure that they can supply flow at.