Case Studies

The compressor casing in a jet engine is an extremely valuable part that requires protection against blade tip abrasion, while aiming for the tightest distance between the case and blade tip for optimal compressor performance. Casings are made of high performing metals to sustain the mechanical conditional constraints as well as the harsh environment, debris and pollutant that can damage various parts. This critical area needs to avoid pollutant release in the downstream part of the jet engine.

At different speed regimes in the jet engine, the airflow in the compressor is regulated by variable stator vanes (VSV), which are generally located at the initial stages of the high pressure compressor. This area experiences relatively high pressure and high temperature that progressively increases with modern engine performances.

Flying a helicopter in an unpredictable and changing environment such as the desert or above the sea can lead to the accumulation of several kinds of potential aggressive contaminants, which are not clearly visibly on the bearings of the main shaft of a helicopter rotor.  These damaging substances may cause jamming, ultimately leading to crash. The sealing of the swashplate is critical as it protects this aviation equipment from dust, sand, and debris.

A high pressure turbine in a jet engine is one of the hottest parts in an airplane since this section is right after the combustion section and can reach extreme temperatures and pressures from the expanding airflow. Maintaining air flow control in this area is key to ensuring the efficiency of the engine because any type of leak is a waste of energy. To maintain a tight control on air flow in the turbine as well as limit vibration, metal shrouds are used, facing the tip of the turbine blades.

As manufacturers continue to improve the efficiency of jet engines, this results in the increase of temperatures throughout these systems. One example is High Temperature Stability (HTS) lubrication oils that are conveyed through a complex circuit and subjected to large temperature variations as well as strong vibration. These oils have been developed to sustain the harshest conditions in order to cool down engine parts and lubricate bearings.

How would a helicopter main gearbox (MGB) successfully function without the proper sealing solution? Rotary lip seals are widely used to seal the oil lubricant within the gearbox and protect it from leaking out at where the shaft enters and exits the gearbox. The main gearbox, also known as a transmission, is a critical part in a helicopter’s airworthiness and safety because it is responsible for reducing high input speed generated from engines and providing appropriate torque to main rotors and other accessory systems.