Precision locking bushes improve productivity
Bushes set feeds for up to 72000 bottles per hour
Special locking bushes from ETP are being used by a major manufacturer of PET blow moulding machines on the feed mechanisms. With outputs of up to 72000 bottles per hour, any downtime on these machines is expensive. The bushes, fitted on the axes of the infeed and outfeed transfer wheels, give reliable backlash free torque transmission. Should any adjustments be required, the ETP bush with single screw fixing allows fast and accurate resetting.
Blow moulding machines to make PET (polyethylene therepthalate) bottles are increasingly used as the material is light, unbreakable, transparent and taste free. Preforms of the bottles are heated to achieve elasticity end then transported by a conveyor and infeed transfer wheel to a blow mould, one of up to 36 on a rotating assembly. Once the bottle is formed, a second outfeed transfer wheel takes the bottles away. The locking bushes fix on the axes of the two transfer wheels and allow both radial and height adjustment.
ETP are specialists in backlash free shaft to hub connections using internal chambers that are pressurised through a fastening screw. The radially mounted setting screw pressurises between the inner and outer walls causing then to expand and grip the shaft and hub. Positioning is easy to achieve, surface pressures are even and low, and the bush can be re-used up to 1000 times. In the UK full information can be found on the Techdrives website www.techdrives.co.uk.
To meet the application requirements ETP supplied a special locking bush based on their ETP-EXPRESS model with a shaft diameter of 40 mm. Six locations in the flange of the bush were provided for the arms of the transfer wheel. To withstand cleaning, the bush
was constructed in stainless steel. Reliable torque transmission of 500 Nm was achieved backlash free, unlike the previously used mechanical connection with polygon profile.
The ETP-EXPRESS improves the accuracy of the feed as there is no backlash, and downtime is reduced by the easy single screw setting that gives quick radial and vertical adjustment. Standard ETP products for shafts from 6 to 220 mm are often ex-stock and details are given on the Techdrives website www.techdrives.co.uk.