Jetpack

• What was needed: Spherical bearings for the connection of drive unit and corset, ball bearings for the control handles, plain bearings at various interfaces
• Requirements: Heat and corrosion resistance, low weight
• Application area: Alternative drives

To dream of flying with a rocket backpack to the limit of what is technically conceivable: The Applied Propulsion project shows how this is possible with vision and new materials. With the Jetpack evo NT, the concept of the "Bell Rocket Belt" from the 1960s was taken and developed further. It consists of an ultra-light corset and a rocket engine that uses highly concentrated hydrogen peroxide as fuel and provides propulsion.

Problem

Due to its rocket propulsion system, the Jetpack evo NT has very few moving parts. Nevertheless, there are some interfaces that rely on storage. Among other things, a solution had to be found for the exposed bearing points of the two control handles, which the pilot uses for lateral control and thrust distribution. The most important storage point is located at shoulder height centrally above the high pressure tanks. It literally has a supporting role in the overall system, as it is not only respon­sible for manageable control of the missile system, but is also the load carrier for the pilot, corset and fuel tanks. The most important requirements for the bearings: the lowest possible weight as well as heat and corrosion­ resistance. The fuel is extremely corrosive, and the water vapour produced for thrust contains free oxygen and is 800°C hot.

Solution

Plain, ball and spherical bearings from igus made of high-performance plastic meet the special requirements. The contact with the rocket fuel and the high temperatures do not bother them. They are also extremely lightweight. With identical dimensions and guaranteeing the necessary strength values, they can save around 80 % in weight compared to their metallic counterparts. In the hand control elements xiros ball bearings with glass balls are used. The absorption of the entire load is undertaken by an igubal rod end. Further bearing points on the Jetpack are equipped with iglidur plain bearings.