Performance of Self-Contained Vertical Shaft, Thrust Bearings

The paper outlines the design requirements and constantly increasing demands, particularly in respect of surface speed, placed upon self-contained vertical bearings. Two types of bearing in present-day use are described and the limitations, inherent in design, upon performance discussed.

Test work on serveral sizes of bearing is described and comparisons made. Data on babbitt temperature are given and, following discussion as to the limits to be place upon babbitt temperature and stress as well as comparison between theoretical prediction and measured values, graphs to a load and speed basis are given showing the present limits of operation of these bearings.

Introduction

In an attempt to define the changes in bearing requirements over a period of time, the speeds and loads of self-contained vertical-shaft bearings supplied by the writers’ company in 1964 and 1974 have been examined and presented in Fig. 1. Intuitively over this period, it has been felt that the speed requirements have increased and this clearly shown by the increase from 8 to 27 percent in bearings supplied at 1,500 rpm, i.e., four pole motor speed. Perhaps surprisingly, the 2-400 rpm range has also shown a very substantial increase in demand. Not apparent from the diagram, however, is the increase in inquiry rate for higher speeds generally at two pole motor speeds, i.e, 3,000 – 3,600 rpm.