Preventive maintenance puts the ‘shhh’ in belt drive systems

A chirping sound, however pleasant when you are taking a stroll through the park, is an unwanted noise when it emanates from a revved up engine at your plant – as it’s often indicative of a misaligned pulley.

Belt drive systems are used extensively in water and wastewater treatment plants to rotate the fans, pumps, and turbines. As with all critical applications, preventive maintenance of drive systems is always better than a reactive approach, as Steve Hittmann, National Product Manager – Mechanical Drives at CBC explains.

Pulley misalignment is a major cause behind premature failure of belts. Even small misalignment of less than one degree can cause the belt to wear out unevenly and fail eventually.

There are two types of pulley misalignments, Steve explains. “Parallel misalignment means that the pulleys’ shafts are parallel but the pulleys themselves are not in the same plane. Angular misalignment is when the pulleys are tilted so that their shafts are not parallel to each other.”

To ensure precise pulley alignment during the initial set up, CBC recommends using Gates EZ Align laser alignment tool, which enables a single operator to simultaneously adjust the pulley to avoid both parallel and angular misalignments.

“The traditional methods of pulley alignment include using a straightedge or a string, but these methods are simply not reliable enough and can be time consuming,” says Iain Street, State Sales Manager – NSW for Power Transmission at Gates.

“The Gates EZ Align units mount magnetically to the face of most pulleys. The transmitter unit projects a laser line onto the reflector unit, which is magnetically attached to the other pulley face. This helps the technician ensure that the transmitted and reflected laser lines match with the respective reference lines,” he explains.

Another potential cause for premature failure in belts could be that the belts are not tensioned to the right amount during the initial set up or have stretched over time.

“When dealing with a quality belt such as the Gates Poly Chain® GT™ Carbon™ Gates Predator® v-belts or the Quad–Power™ 4, you do not generally require re-tensioning during the life of the belt. However, some poor quality belts tend to stretch and so a re-tensioning might be required,” says Steve.

“When it comes to belt tensioning, both over-tensioning and under-tensioning adversely affect the life of the belt. For example, if v-belts are under-tensioned, they can slip. Slippage generates heat and will result in cracking and belt failure. On the other hand if belts are over-tensioned, belt and bearing life can be reduced,” he adds.

Gates offers solutions for this too. The Gates 508C Sonic Tension Meter ensures simple and accurate tension measurement by analysing sound waves from the belt through the sensor.

“The 508C Sonic Tension Meter is suitable for multi-ribbed belts, v-belts and synchronous belts and measures the belt tension easily and accurately every time,” says Street.

Apart from the EZ Align laser alignment tool and 508C Sonic Tension Meter, Gates also offers a range of safety tools for installation and maintenance of drive systems.

The BIRD is a Belt Installation and Rotation Device that the maintenance personnel can use to lower the risk of finger and hand injuries due to hands getting caught in pinch points during routine installation and maintenance.

“Prior to the launch of the BIRD, in order to inspect or install a drive, personnel would pull on the belt or grab the edges of the pulley or sprocket to turn the drive. Regardless of the care taken, this procedure is inherently dangerous,” says Street.

Gates and CBC offer these and more Gates maintenance and installation tools as part of the Gates maintenance kits.

“The Gates maintenance kits include all of the tools required to safely install and align the drive system. Customers can choose from multiple kits depending on their requirements and budgets,” Hitmmann says.

Gates also works closely with CBC to provide online or in-person training to the maintenance team as part of the two companies’ engineering and technical services, says Street.

“We have a 3-4 hour on-site training program that we offer either on behalf of CBC or in conjunction with them,” he adds.