In a processing line for the production of steel rod and bar, the fixing of the feed rollers has been made more efficient by the use of an ETP-HYLOC shaft to hub connection. As well as accepting the high radial forces and giving accurate concentricity, the HYLOC locking bush greatly reduces the time required to change the rollers.
The hardened steel feed rollers grip the rod or bar with axial force, driving it to the next stage of the process. A change in material size or the inevitable wear of the profile cut into the rollers requires that the rollers be changed. Important factors are the time required to change, the accuracy of the radial run-out and the ability of the connection to withstand axial forces and shock loads measured in tonnes.
ETP-HYLOC consists of a double-walled sleeve, which encloses a tapered, moveable piston, which is moved through hydraulic pressure and is mechanically self-locking. In the
flange there are three connections in both the radial and axial direction that can be freely chosen. Mounting and dismantling is done with a hand or motor pump. Normal working pressure is 1000 bar.
In this application the HYLOC locking bush proved capable of run-out figures below 0.02mm, even for shafts up to 220mm. Once mounted, no hydraulic pressure remains in the bush and the resulting mechanical connection is easily able to withstand the high radial forces. Downtime to change rollers is dramatically reduced. After pressurisation the HYLOC freely releases in a process taking a few minutes to make the connection. On reassembly the bush does not move axially during pressurisation and the process is clean with no escaping oil.
The ETP-HYLOC bushes are available in the UK through Lenze Limited. Standard models exist for shafts up to 220mm and customised specials are available for larger sizes. Other typical applications are the fixing of large gears, turbine impellors, flying shears, rotary test rigs and axial compression test machines.