Over the years, Kingsbury engineers have refined the design of tilting pad journal bearings to increase performance, enhance operating stability, and extend operating life. Properly selected bearings are crucial to the performance of rotating equipment. Conversely, the cost and inconvenience of a poorly selected bearing can be catastrophic. The purpose of this information is to provide both the designer and the user of rotating equipment with a handy guide to the proper selection of Kingsbury pivoted-shoe journal bearings, as well as an overview of where they are best applied.



Why pivoted shoe journal bearings?



As rotating machinery has evolved, many types of bearings have come and gone. Today, rotational speeds and power density levels continue to increase, along with the complexity of the machinery. The dynamic characteristics of such complex machines depend heavily on the journal bearings.



The simplistic plain journal bearing, inherently unstable at light loads, can experience self-excited subsynchronous vibration during operation ? a phenomenon known as oil whirl. While some bore profile modifications have been successful at raising the stability threshold when new, a fixed geometry bearing is susceptible to damage from misalignment, unbalance, wear, or shock loading. The inherent design characteristics of a pivoted shoe journal bearing, on the other hand, eliminate all concerns about oil film instability. At the same time, the mechanical design of a pivoted shoe journal bearing provides excellent resistance to shock and unbalanced loading while allowing continued operation during conditions of misalignment or wear.OptionsOptional Features



Floating seals, Code FS



When oil flow out of the bearing along the shaft has to be controlled, floating seal rings are recommended. Both shoe retaining plates are fitted with floating seal rings 



Instrumentation, Code MT



Journal shoes are instrumented with thermocouples or RTD's to monitor bearing temperatures. The type of instrumentation required and sensing position (shoe center or trailing edge) should be indicated Specify both on the 'Inquiries' form, page 29.



Proximity Probes, Code PP



Customer furnished proximity probes are mounted radially on special shoe retaining plates. The probes are mounted 90° apart for monitoring shaft position or orbit 



High Pressure Lift, Code HL



Shoes are modified for the injection of high pressure oil to establish an oil film at start-up or during very low speed operation. Kingsbury can also supply high pressure lift systems if required (see Catalog W).



Thrust Capability



Thrust bearing capability can be incorporated in a pivoted shoe journal bearing with suitable shoe retaining plate modifications.



Code TF



Thrust face with flat land, babbitted bumper incorporated into one or both of the shoe retaining plates.



Code TT



Same as flat face bumper except with taper land design to handle higher axial loads.



Code TS



Thrust shoes (NE style bearing) mounted on one or both shoe retaining plates. For more information, refer to section on Journal Thrust.