What is a Bearing Proof Load Tester?

Aircraft bearings are key components in aerospace applications that are used to support heavy loads and ensuring smooth operation. In order to avoid catastrophic failure, it is paramount to ensure that critical application bearings have been mounted safely and correctly.

The installation of a bearing involves several steps, including inspection, cleaning, lubrication, and alignment, to ensure proper function. One method of securing bearings in place is bearing staking or swaging, which involves applying the appropriate amount of force to deform the housing material around the bearing. This creates a mechanical interference fit without damaging the bearing or its components, or the bearing housing. This method, using bearing swaging or staking tools, helps prevent the bearing from moving out of position or rotating during operation.

However, even after following the correct mounting procedures, there is still a risk that the bearing may have been damaged during installation or has been subjected to an excessive load. As a result, proof testing is critical to ensure that the bearing can withstand its specified loads and operate safely.

Bearing proof testing involves applying a load that is higher than the expected operating load to the bearing to verify its ability to withstand the stress. If the bearing can withstand the load, it has passed the proof test and is deemed safe for use. However, if it fails the test, it must be replaced or reinstalled.

Why selecting the right load cell is key

Load cells are critical components in bearing proof load testers as they are used to measure the applied force to the tested bearing, providing accurate measurements of the bearing's ability to handle the intended loads. Load cell sensors can be designed to measure a wide range of loads, from a few grams to several thousand pounds with high accuracy, making them ideal for testing bearings that are designed to handle heavy loads.

In a bearing proof load tester, load cells are placed between the load source and V-Groove of the bearing being tested. The load source can be manual (i.e. torque wrench) or an automatic bearing proof load tester. As the load is applied, the load cell measures the force being applied to the bearing and sends this data to the IHH500 Handheld Display. If the data indicates that the bearing cannot handle the load, it must be replaced or reinstalled to ensure safe operation.

The linear displacement sensor, typically a DTI gauge, is usually placed between the bearing and the load source. As the load is applied, the bearing will experience some displacement. The linear displacement sensor measures this movement and sends the data to a control unit, where it can be recorded and analyzed.