Product Details Supplier Info More products

Locking bushes from ETP are being used as part of the Neuron project, led by Dassault, to build an unmanned combat aerial vehicle (UCAV) demonstrator.

The build makes use of reconfigurable fixtures that rely on the holding properties of ETP-Express locking bushes.

These adaptable fixtures, known as hexapods, support the fuselage during assembly.

As additional parts to the fuselage are built in different assembly stages, new fixtures are added or moved to new locations on the structure, giving maximum support and enabling optimal accessibility for the operators.

Hexapods are more commonly found with powered actuators, but a project between the University of Linkoping, ETP and SAAB sought to develop it for workholding.

Here the additional advantages of high rigidity, ability to accept side loads, very precise adjustment and small footprint become relevant.

On each leg, an ETP-Express locking bush is fitted to allow sliding movement until tightened, when it becomes rigid without backlash.

Hexapod holding fixtures can be laser aligned and locked in position.

When the time comes to reconfigure the fixture, the ETP bushes are simply loosened, giving immediate free release of the legs.

The ETP-Express shaft locking bushes are more commonly used for connection of hubs, sprockets, cams and gears to rotating shafts without using keyways.

They work by pressurisation of a cylindrical chamber that sits between thin inner and outer walls, causing them to expand and grip the hub and the shaft.

Pressurisation that sets the rated performance is easily achieved by tightening a single radially mounted screw.

ETP-Express bushes have features that are matched to the hexapod application.

As well as torques transmitted radially, ETP-Express is equally good at transmitting the axial forces present in the hexapod.

Partial tightening of the pressurisation screw achieves a light resistance force against movement, which is ideal for setting the position.

Once set, the full tightening torque is applied without any resulting axial movement that could disturb the set position.

Loosening the single screw gives immediate and free release.

The ETP-Express bush is available from Techdrives in a range of sizes for shafts of 15 to 100mm.

The Neuron project will produce an unmanned aerial vehicle to serve as a technology demonstrator, with the first flight expected in 2011.

View full profile