Alignment and tensioning of belt drives made easy

FAG Industrial Services (F’IS), the maintenance and condition monitoring division of the Schaeffler Group, has extended the range of functions offered by two of its proven measuring instruments – SMARTY2 and TRUMMY2 – used for aligning and tensioning belt drives and chain sprockets.

Not only do the new functions make these precision instruments even easier to use, they also help to reduce wear and tear on the drive components. A correctly aligned and tensioned belt drive or chain sprocket means less friction and vibration are generated by the drive system, which means less wear on belts, belt pulleys, bearings and seals. This means the running time and reliability of the machinery is increased, energy costs are kept to a minimum and overall plant efficiency is improved.

Ideal for checking the alignment of belt-driven fans, compressors, conveyors, pumps and ventilators, the ‘FAG Top-Laser SMARTY2’ measures and adjusts the alignment of drives and pulleys significantly faster and more accurately than using conventional methods. With its new, optional real time digital display of readings, belt drives can now be aligned even more quickly and accurately.

The device displays the parallelism and misalignment of both pulleys and is suitable for both horizontally- and vertically-mounted machinery. Only one person is required to carry out the alignment and the device can also be used on non-magnetic sprockets or pulleys.

Used on flat, toothed and Vee belts, the SMARTY2 detects angular or parallel misalignment, or a combination of the two. Mounting can be achieved in just a few seconds. The user can clearly see the laser beam on the target marks. Once the user has adjusted the laser beam to coincide with the slots in the target marks, the machine is correctly aligned.

The target marks come in optical or digital form. For the digital version, adjustment values are shown in real time on the display. Angular misalignment is displayed as degrees and parallel misalignment in millimetres.

In addition, because the device is so lightweight (270g) the emitter and target marks can be attached to non-magnetic drive pulleys using strong, double sided adhesive tape.

Belt tensioning tool
As well as alignment, correct belt tension is a prerequisite for maximising the life of a belt drive. The ‘FAG Top-Laser TRUMMY2’ is a high precision opto-electronic handheld measuring instrument for optimising belt tension (strand force). Its improved design enables users to perform measurements using only one hand.

TRUMMY2 consists of a cableless measurement probe and a robust, handheld control unit. Measurement parameters are shown in the display either as frequency (Hz) or force (N). The device also has a measurement probe with cable for areas that are difficult to access.

To calculate the optimum strand force (belt tensioning force) for a drive, the belt mass and length are entered into the instrument. By generating an impulse – for example by striking the stationary belt – the tensioned belt is excited to its natural vibration. The individual static natural frequency generated is measured within seconds by the TRUMMY2’s sensor using ‘clock pulse light’ and shown on the display. The strand force is calculated and then compared with the specified nominal value.

This measurement technology (clock pulse light) is superior to conventional methods – such as measurements using sound waves – because the measurement result is not distorted by disruptive external influences.

The optimised belt tension increases the service life of the belt drive. Moreover, it prevents potential consequential damage to rolling bearings, seals and shafts caused by excessively high belt tension. In this way, costly unplanned downtime is minimised.

For more information on F’IS products and services, please visit www.schaeffler.co.uk or telephone the marketing department on 0121 351 3833.