Motor—belt drive—bearing housing—fan: high overall vibration, motor overcurrent
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This post was last edited by jmdc on 2017-7-13 22:26. Motor — belt drive — bearing housing — fan (flue gas exhaust fan for a hot air furnace; flue gas temperature: 100°C). The entire assembly has spring shock absorbers; there is significant vibration. An analysis of the causes of motor overcurrent is required — is there any connection between this overcurrent and the excessive vibration?
In my opinion, the motor overcurrent is related to the motor itself, and has little to do with vibration; it is necessary to check which part is experiencing increased friction
What should be the maximum allowable temperature at the bottom, between the two heat sinks, when this motor is in operation to consider it normal? For a bearing housing like this that uses circulating water, what is the maximum normal temperature for its outer surface during operation?
What should be the maximum allowable temperature at the bottom, between the two heat sinks, when this motor is in operation to consider it normal? For a bearing housing like this that uses circulating water, what is the maximum normal temperature for its outer surface during operation?
It seems so; check the fan impeller to see if anything is stuck to it
To analyze the vibration of equipment, it is necessary to consider various aspects: 1. Did it vibrate during previous operations? When did the vibration start, and what changes occurred in operating conditions? 2. Remove the belt and run the motor alone – does it vibrate? 3. Check whether the fan’s bearings are damaged by opening the cover, or examine for any play or vibration in the shaft heads. 4. Whether the dynamic balance of the fan rotor has been disrupted – dust and sludge accumulating on the blades over time can affect the dynamic balance. Check and analyze one by one.
Vibration has little to do with motor overcurrent. Main vibration checks: dynamic and static balance of the impeller, whether the shaft is bent, installation accuracy, etc ； Motor overcurrent check: Check whether the belt is too tight, the parallelism of the pulleys, etc. This type of motor can operate fine at 90°C, with bearing temperatures not exceeding 85°C.
There are three belts on the pulley, and two of them are loose. Will this lead to a decrease in transmission efficiency, thereby increasing the load on the motor? Is it normal for the temperature of the outer surface of this fan bearing housing, through which circulating water flows, to be 70°C?
As long as there is no slipping, it won’t affect efficiency. Remove the belt and turn the shaft by hand to feel the inertia 70°C on the surface depends on the ambient temperature as well; it’s a bit high.