Transformer oil circulating pump with forced lubrication - has helical slots in shaft and radial slots pumping oil allowing higher oil temp. and reduced wear in bearings

摘要

The oil pump and driving electric motor are mounted on a common shaft and immersed in the transformer oil inside the transformer housing, it pumps the oil to circulate around the core and through heat exchangers. To aid the lubrication of the bearing oil is bled into the bearing from the motor housing through a hole (128) in the casing. It circulates through helical grooves (118,116,120,121) cut into the shaft over the bearing and wound in the opposite direction to the sense of rotation, and then flows out through radial grooves (122) in the end bearing (114) aided by centrifugal force. The motor is a small sealed unit which requires practically no maintenance. Care is taken to prevent contamination by metal particles detached from the bearings as a result of frictional wear. A system to detect bearing wear is incorporated to activate an alarm or stop the pump when a degree of wear is detected.