The ETP Hyloc bush is a unique design based on hydromechanical principles that gives big advantages for the assembly and disassembly of hubs to shafts. It takes away problems & sticking and fretting with major savings in fitting time. Hyloc replaces keyways that have problems with fitting, backlash and fretting. Hyloc also replaces taper connections which are difficult to release and particularly prone to damage from dirt contamination. Being self-contained, Hyloc creates a backlash free shaft connection that is easy to adjust, fast to fix and quick to release.

Hyloc locking bushes are available from Techdrives in a standard range for shafts from 50 to 220 mm. Customised models can be supplied for larger shafts. Connections can be made to gears, rolls, turbine impellors and other types of hub using surfaces that are machined parallel and to standard tolerances. Hyloc works using hydraulic pressure from a hand or electric pump. It consists of double-walled sleeve which encloses a tapered piston which moves axially under the hydraulic pressure. Connection ports allow the piston to be driven into the sleeve which forces the walls outwards, creating a friction connection between the shaft and the hub. When the pressure is removed, the piston locks mechanically forming a secure joint with very high radial load capacity. The bush is released by applying pressure to ports that connector to the opposite end of the piston, forcing it back down the sleeve. The whole process is fast, easy and clean compared to alternatives of keyways and taper joints.

Hyloc is used in rolling mills, water turbines, feed rolls and dynamometers. The common factor is the need to save time on disassembly. Torque ratings are particularly high, for example 30kNm on a 100mm shaft, and the torques is proportional to the mounting pressure so it can be adjusted. Normally bushes are set at 1000 bar, but anywhere in a range 800 to 1200 bar is possible. During assembly it is easy to adjust and precisely position the hub both radically and axially. Once set the Hyloc has excellent concentricity with run-out values of 0.01 to 0.02 mm allowing connection of output gears to gearbox shafts.

Hyloc locking bushes are manufactured by ETP and are available in the UK through www.techdrives.co.uk. Links from the product page lead to a simple animation video showing Hyloc operation. Where medium to large shafts and hubs need to be precisely assembled or reliably disassembled, Hyloc is the product that saves the fitters’ headache and the company’s time.