Page 324 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

304 Major Process Equipment Maintenance and Repair

Figure B-7. Double reduction high speed gear unit (cut-away view) with
double helical gearing and a simple pressurized lubrication system pow-
ered by a shaft-driven oil pump. This unit exhibits gearing arranged in a
“nested” design, where the high speed gear set is split and the low speed
gear set is nested between the two halves. The main advantage of this
particular arrangement is that it equalizes the loading on all bearings. It
also utilizes the available space more efficiently than some other double
reduction designs.