EQH Thrust Bearings
EQH Thrust Bearings
Our equalizing flooded thrust bearing is the product of years of design refinement and application experience.
Elements and Design of Kingsbury Thrust BearingsBeginning with a fundamental review of the Kingsbury thrust bearing, this section lists basic bearing elements and how they work, as well as design options and accessories.How Kingsbury's Thrust Bearing WorksA thrust bearing transmits axial loads to the foundation or machine support of rotating machinery.Our equalizing thrust bearing actually transmits the load through a self-renewing film of oil during operation and a unique force-balancing action distributes the load across the shoes. Working surfaces touch each other only during start-up and shut-down. Otherwise, these surfaces are separated by the fluid film, so surface wear is minimal, and bearing life dramatically lengthened.The Kingsbury thrust bearing offers many operating advantages, including:
- Excellent shock absorbing capacity
- Superior damping characteristics
- Life span equal to that of the machine
- Versatility in application
- Performance monitoring capability
Basic Elements
Here is a quick review of the basic elements in a Kingsbury equalizing fluid film thrust bearing:
Rotating Thrust Collar The forged steel collar, which is rigidly attached to the shaft or rotor, transmits the thrust load from the rotating shaft to the bearing shoes.
The collar faces are ground, then lapped flat and smooth to reduce frictional loss and increase load capacity.
Stationary Pivoted Shoes
The shoes (also known as pads or blocks) in our thrust bearings have three parts:
Shoe Body Shoe thickness has been selected to reduce the amount of thermal and elastic deformation. For a center-pivoted shoe, a certain amount of thermal or elastic crowning is necessary for the thrust shoe to carry load, whereas excessive crowning reduces load-carrying capacity. Therefore, we have carefully optimized our designs so that the elastic or thermal crowning of a Kingsbury thrust shoe yields maximum load-carrying capacity.
Babbitt Face The thickness of the babbitt has also been optimized to increase compressive strength of the babbitt while maintaining the very desirable embedability characteristic of babbitt. This material allows small amounts of foreign particles that are in the lubricating oil to embed themselves in the babbitt rather than score or damage the rotating collar.
Shoe Support The spherical pivot on Kingsbury thrust shoes allows the shoe to tilt not only in the direction of rotation but also in the radial direction, compensating for some misalignment between the thrust bearing face and the rotating thrust collar. The ability of a shoe to pivot as well as to tilt increases load-carrying capability at all shaft speeds. The thrust shoe pivot, or shoe support, and the upper leveling plate where the thrust shoe pivot makes contact, are both made of high carbon steel, heat-treated to Rockwell 50C, to prevent damage to the pivot contact areas.
