Measure axial thrust
With the METAX solution for measuring axial thrust, axial forces are measured directly in real operation — not just calculated. The sensor system enables precise measurement and is easy to install, ensuring reliable monitoring and evaluation of forces in a wide range of applications.
Determine axial thrust on centrifugal pumps
Axial thrust and its effect on wear
The reliability of centrifugal pumps depends decisively on the wear and tear of the fixed bearing. In particular, the axial load on the fixed bearing due to the hydraulically generated axial thrust determines the service life of the bearing.
With our patented axial thrust measurement, you can determine the axial forces during operation of the pump. You can plan and optimize service intervals and set the pump's operating point so that it has the longest possible run time until the next necessary repair.
Axial thrust is the resulting axial force, which is mainly caused by the difference in pressure on the impeller and is supported by the shaft on the fixed bearings.
The residual axial thrust is a quality feature of pumps and is checked during the “factory acceptance test”, especially in the case of multi-stage centrifugal pumps.
The residual axial thrust significantly determines the life of the bearing. Changes in axial thrust during operation indicate a changed operating point.
Absorption of axial thrust through fixed bearing
Centrifugal pumps or centrifugal pumps use centrifugal force to deliver liquid. These pumps have one or more impellers (purple), a bearing for radial support (green) and an angular ball bearing (orange) to absorb axial forces from the impeller. The front bearing (green), which only absorbs radial forces, is usually designed as a cylindrical roller bearing, deep groove ball bearing (floating bearing) or as a slide bearing.
The axial thrust is absorbed by the rear bearing arrangement (fixed bearing in orange). The fixed bearing is designed either as a deep groove ball bearing, as a double-row angular contact ball bearing or as two angular ball bearings in an O or X arrangement. Angular contact ball bearings to absorb the high forces that can arise in the process. Double row because axial thrust reversal can also occur.
Axial thrust compensation and residual axial thrust
The axial thrust can be reduced by a back-to-back design of the impellers in multi-stage pumps. In this case, the impellers are symmetrically distributed with respect to the suction port, so that half of the impellers generate thrust in one direction and the other half in the opposite direction.
In single-stage pumps, the axial thrust is reduced either by compensating holes in the impeller or backblades, so that a good compromise between hydraulic efficiency and bearing life is achieved.
Solution for determining axial thrust
We use precise knowledge of bearing geometry and our METAX SAW technology to determine the influence of axial thrust on bearing kinematics.
This allows you to measure the axial thrust of your hydraulics with the original bearing support. For this purpose, the BeMos L8 sensors mounted in the bearing support via compression screws and attached to the BeMos one controller connected.
With our axial thrust calibration device, we calibrate your bearing support design for a specific range of forces and speeds. You can then measure your hydraulics. Measuring axial thrust with METAX technology works both for centrifugal pumps and for positive displacement pumps, which use angular or deep groove ball bearings as fixed bearings.
| applique | Storage type | measurement range | σ/ resolution |
|---|---|---|---|
| pump | CSC 6312 | 0-10 kN | 105 N |
| turbine | SKF 6011 | 0-4 kN | 75 N |
| pump | FAG 3607 | 0-2 kN | 44 N |
Determine in 3 steps
and plan how to BeMos L8 sensors can be installed in your warehouse rack.
and send us the setup with motor on a base plate. We will provide you with a link to download the CAD data for the calibration module.
Play the calibration curves in the BeMOS one controller and send you back the calibrated bearing support with measurement system. Start your measurement.
Our demonstrator setup
With the demonstrator, sensors and measurement systems for pump condition monitoring can be demonstrated live.
For this purpose, the typical pump drive train was built on a small scale as a demo starter.
The demonstrator consists of a drive that can accelerate the drive shaft up to 2,300 rpm via a belt.
A deep groove ball bearing as a fixed bearing and a cylindrical roller bearing as a floating bearing keep the shaft in position. Die sensed mechanical seal, as well as rolling bearing monitoring and axial thrust measurement, can be shown live.
Bearing monitoring and axial thrust measurement
Behind the fixed bearing, a force can be applied axially to the shaft by hand using an adjusting screw and a plate spring package. The force can be increased from 0 newtons to approx. 300 newtons.
The fixed camp is with BeMos L8 sensors equipped and the BeMos one controller was calibrated for axial thrust measurement.
It can be shown that BeMOS can be used, on the one hand, to identify whether the bearing is being operated under load and the rolling elements are slipping (the case is the case with a minimum load of up to approx. 100 Newton). On the other hand, once a “slip-free” state is reached, the axial force is determined and output.