Offset power transmitted more smoothly

Problem: . The usual solution is to use gears, but even the best designs tend to introduce a small amount of vibration. Alternatives include the use of belt or friction drives, but these may not allow the transmission of sufficient torque, or may put an unwanted bending moment on shafts and bearings. Solution: The German company Inkoma Maschinenbau offers a parallel crank coupling, which allows the smooth transmission of very high torque from one shaft to another parallel shaft. The device comprises three disks, each pair interconnected by at least three links. The first disk is connected to the input shaft and the third disk to the output shaft. The central disk is situated between the input and output disks, connected to them by the links. Units are available to accommodate parallel displacements up to 320mm and torques up to 450,000Nm. Each unit is supplied ready for use and lubricated for life, but may be additionally lubricated via the grease nipples in the links. Pre-load is 10Nm to eliminate backlash. Applications: UK vendor Drive Lines Technologies describes how the devices may be used in extrusion haul-offs and to achieve very fine finishes on copper drums used in the printing industry. They are said to have extremely long lives if used with the 'right design considerations'. These include not operating beyond 95% of the stretched displacement, and not within 25% in order to prevent instability of the centre disk. TS Drivelines http//:www.drivelines.co.uk