3
Babbitt
Shoe
Spring
Base
Figure 4.--Spring loaded thrust bearing.
Base
Adjusting Screw
Babbitt
Shoe
Figure 3.--Adjustable shoe thrust bearing.
three bearing types would look very similar. All three use babbitt lined, pie shaped bearing shoes
that are tiltable to allow a wedge of oil to form automatically between the shoes and the thrust
runner. The differences lie in the supporting structure for the bearing shoes.
that are tiltable to allow a wedge of oil to form automatically between the shoes and the thrust
runner. The differences lie in the supporting structure for the bearing shoes.
The adjustable shoe thrust bearing uses a jack screw under each of the shoes for adjusting the
height and loading of the shoes. Figure 3 illustrates the basic components. A pivot point on top
of each of the jack screws allows the shoe to pivot freely and form the required oil wedge.
height and loading of the shoes. Figure 3 illustrates the basic components. A pivot point on top
of each of the jack screws allows the shoe to pivot freely and form the required oil wedge.
The spring loaded thrust bearing consists of the bearing shoes supported by a number of coil
springs on the baseplate, as shown in figure 4. The springs are usually preloaded to a point that
there is very little deflection with the static weight of the rotating parts that they support. With
the addition of the hydraulic down thrust of the turbine, the springs will deflect to equalize the
load between shoes. A variation of this design uses a single Belleville washer or conical spring
under each shoe, rather than multiple coil springs.
springs on the baseplate, as shown in figure 4. The springs are usually preloaded to a point that
there is very little deflection with the static weight of the rotating parts that they support. With
the addition of the hydraulic down thrust of the turbine, the springs will deflect to equalize the
load between shoes. A variation of this design uses a single Belleville washer or conical spring
under each shoe, rather than multiple coil springs.