Temperature of the pump bearing cover
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A new CZ water pump, with a capacity of 50 tons and a head of 50 meters. During testing, it was found that the temperature of the bearing cover adjacent to the motor was normal at 50 degrees. For the bearing cover adjacent to the impeller, measurements showed that the temperature was 57–60 degrees in the horizontal direction; however, a higher temperature of 72 degrees was detected in the vertical direction. But as long as one moves away from that point, the temperature drops back below 60 degrees. In other words, there is one spot on the bearing cover where the temperature is higher. The temperature of the bearing housing itself was measured at 54 degrees. Please discuss what’s going on here; is there a problem with the axial clearance? Why is there a high temperature at the impeller end?
There may be some errors in the measurements; the gland is quite small, so it’s impossible for there to be a large difference in temperature. You can feel it with your hand – you can touch it when the temperature is in the 50s degrees, but not when it’s in the 70s degrees
If the pump bearing gland temperature rises due to a small axial clearance, which end’s bearing gland temperature increases, or by how much? Is it from the motor side or from the impeller side? Are the bearing caps at both ends still at high temperatures?
Are the bearings of the impeller 6306 or NU306?
Continue to monitor the temperature to see if it rises; if it remains constant within this range, it can be used further, with the temperature ideally not exceeding 90 degrees.
If the bearing temperature no longer rises, then this temperature is fine; it is suspected that too much oil was added to the bearing on the non-drive side
The impeller balance is not proper, or the shaft runout is out of tolerance
The bearing may be defective at the area with high temperature; pay close attention.