Hitting top gear with drive technology

An investment in expensive machinery is of limited value if the critical standard components that comprise it are ineffective, writes Marcus Schneck, chief executive of standard component manufacturer Norelem

Engineering automation is made possible by the integration of multiple standard components and the amalgamation of multiple drive systems. Gears, motors, ball screws and couplings, integrated with frequency converters at a single source, play a vital part in enabling effective automation in most modern manufacturing facilities.

However, while the application of these standard components can support greater automation, the lifecycle of drive technology very often depends on how these individual components are used, maintained and combined. To understand how to yield maximum value from drive technology, it is important for engineers to familiarise themselves with the individual components themselves.

Gears are integral to the smooth operation of most machinery but these components are subject to wear over time, and must be replaced periodically. Care should be taken to specify high-quality components which enable longer lifecycles and help to avoid costly downtime or damage to machinery.

Gears made from lower-quality materials, unable to cope with the operating conditions or which are imprecisely machined or fitted, are likely to fail with greater regularity than better-quality parts, to the detriment of other parts of the gear drive.

When fitting spur gears, it is essential to align the shafts correctly, since inaccurate fitting can reduce tooth contact, causing wear and excessive noise. They must be fitted firmly to prevent them slipping towards the shaft.

Marcus Schneck (Credit: Norelem)

A ball screw, also referred to as a ball screw linear actuator, converts rotation into linear movement. In this regard, it acts in a similar way to a gear rack (although the construction of the two is entirely different) but the ball screw allows for greater precision and efficiency. Ball screws comprise a threaded screw, which acts as a 'runway' for the nut element, which is actually a component containing re-circulating ball bearings, in which the balls and the ball return are integrated. Ball screws are very commonly seen in machinery, where they may be preloaded to eliminate any potential backlash.

These components have no self-locking mechanism owing to their low rolling friction, and reduction transmissions or engine brakes are generally used as braking systems. They are common in industrial applications, and are generally quite resilient, but they do have to be replaced over time and are susceptible to contamination. Poor circulation of the ball bearing can increase servo load, while excessive backlash generated by a ball screw can compromise accuracy precisely where it is needed most, in equipment such as CNC machines.

Couplings are used to transmit torque between two shafts. Common signs of coupling failure include abnormal 'screeching' noises and excessive vibration. Improper installation, excessive loading, contamination, lack of maintenance and inappropriate size selection are also not unusual.

It is when these components are appropriately combined in an optimum operating environment that they become most effective, enabling seamless automation in a raft of critical machinery found on almost every shop floor. Drive technology is expected to play an increasingly prominent role in the growth of the UK manufacturing sector, as industry strives to become more productive, competitive and effective.

Automation will play an integral part in this journey but an investment in expensive machinery, however justified, is of limited value if the critical standard components that comprise it are ineffective.

Frequent upkeep, maintenance, and replacement of drive technology components is the only way that machinery operators can continue to achieve maximum return on their investment, in terms of cost, improved lead times and greater productivity.