Product Details Supplier Info More products

German gear specialist Stelter Zahnradfabrik is using HWR’s Inozet pendulum bridges, available from Thame Workholding, to machine gear base bodies for car gearboxes and wind turbines from solid ball-bearing quality steel and help it to achieve the required mean roundness error of less than 10 micron without additional grinding and honing operations.

The bridges consist of three pendulum segments that can be mounted to any conventional three-jaw chuck, whether with tongue and groove or fine serration interfaces.

A three-jaw chuck is easily converted into a compensating six-jaw chuck with the clamping force at each point of contact reduced accordingly, according to the company.

Key specifications

  • The mounted bridges float, which reduces the deformation forces to a minimum while still providing safe and secure clamping
  • When a workpiece is clamped with the Inozet pendulum bridges, the error is reduced to 5 micron on the internal diameter and almost down to 10 micron on the clamping side
  • The pendulum segments are positioned on the existing chuck to ensure that the effective force of all six jaws is always pointing towards the centre
  • HWR calculates the exact mounting points for each chuck
  • The segments each have a pair of top jaws that are mounted via two screws
  • When the chuck is closed, one of the jaws of each pair pushes itself against the workpiece
  • On contact, the second jaw oscillates into position and all six jaws are then clamping simultaneously and uniformly
  • Each jaw pair can be moved radially, meaning that the entire clamping range of the chuck is covered with one set of gripper jaws mounted onto the pendulum bridges
  • Can be used for internal and external machining
  • Both hard and soft jaws, as well as special jaws, can be used
  • If a workpiece is machined to size on the OD, Stelter Zahnradfabrik is able to lock the Inozet chuck in place, bore out the soft jaws and clamp the component accurately via six points
  • Machines large planet gears destined for wind-power stations

Thame Workholding

View full profile