Tilting Pad Thrust Bearings with Load Measuring Mechanism

The journal bearing forces in bearings can often be determined quite accurately by using the rotor weight in many turbomachinery applications. This is in general more difficult with regard to the thrust bearing forces which often will be determined by the fluid mechanics within the turbomachine. However, the thrust forces acting on just one thrust bearing may also result from more than just one rotor in complex turbomachinery trains. The complexity of these calculations of axial forces in turbomachinery trains, including a vast number of different operation points, could lead to certain inaccuracies.

There are different options for measuring the thrust forces in tilting pad thrust bearings. One of the most popular options to measure the thrust forces in tilting pad thrust bearings is the use of load cells. These load cells (sealed measurement devices) could either be installed into the back of all individual pads or in the retainer (support bearing body) of the bearing. In any case, the number of thrust pads determines the number of load cells that have to be used.

Another method is the use of a spacer with strain gauges or alternatively the use of special thrust bearing support rings (retainer) with flexible pad supports. In the following, we would like to show two of these options for thrust force measurement in more detail.

Thrust force measurement using load cells in the thrust tilting pads

In this case, there are pockets machined into the back of the individual tilting pads where a special load cell is implemented. This load cell must be temperature-stable, oil-resistant, and oil-tight. It is also important to ensure that the shape of the tilting point on the load cell is suitable for hydrodynamic tilting pad thrust bearings.

This force measurement method can only be used for medium to large thrust tilting pads due to the dimension of the load cells. The use of a self-equalizing system is also recommended.

Thrust force measurement using special bearing support rings with flexible pad support

For smaller pad sizes or thrust bearings without self-equalizing systems, the thrust force measurement is possible by using of a special support ring with elastic support for the thrust pads.

Strain gauges are used to measure the deformation of the flexible pad support. This allows to calculate the forces on each single pad and thus the total force on the thrust bearing.

If you are interested in more detailed information about the different options for measuring the thrust forces in tilting pad thrust bearings, please do not hesitate to contact us.??

Kindly we want to remind you that Miba's recommendations for the use of its products are based on experience and technical standards, and do not represent any assurance of characteristics or warranty commitments. Any warranty or guarantee of merchantability or fitness for a particular purpose is excluded. Thank you for your well-understanding.