Insights and advice on PT belts

In the Reliability Forum department of Reliable Plant magazine, suppliers provide their insights to a question posed by editor Paul V. Arnold. This issue, the question went out to manufacturers of power transmission belts:

“In your opinion, what is a common mistake end-users make when selecting a power transmission belt?”

This reply comes from Skip Scherer, a communications manager for the Goodyear Tire & Rubber Company.

“Don’t forget to consider belt noise.

“Belt noise can impact workers close to operations or neighbors in nearby homes. Using belt-and-sprocket systems designed to reduce noise can mean the difference between meeting OSHA sound-decibel requirements and incurring high costs associated with workplace monitoring, protection, training and testing. It could also avoid the phone call from an irate and sleepless local resident. In sound-sensitive work areas, use synchronous systems that avoid belt teeth slapping into sprockets and generating an impact noise, which is the familiar whine sound at frequencies determined by tooth pitch and drive operating speed.

“Consider belt profiles that gradually roll each angled belt tooth through a sprocket, eliminating impact noise. Also, self-tracking tooth patterns eliminate the need for sprocket flanges, another source for irritating rubbing noises. Keep in mind that noise is usually created by an energy-robbing action.

“A progressive tooth engagement design can be up to 19 decibels quieter than a synchronous belt with a conventional straight-tooth profile.”

To learn more about belts, visit www.goodyear.com.

This reply comes from Michelle Davis, an engineer for Gates Corporation.

“Whether replacing an existing belt or converting a roller chain drive to a synchronous belt system, the most common mistake end-users make is not having sufficient information about the original belt or drive system.

“To recommend a replacement belt, the distributor or manufacturer needs the belt part number (for example, 3V400) and belt manufacturer. This information may be found in maintenance or purchasing records, or on the belt label. If this information is not available, the end-user may provide the physical dimensions of the original belt, and any special requirements of the drive (such as heat, conductivity or chemical resistance). However, Gates Corporation engineers say the part number is preferred, if available, as a proper replacement belt cannot always be provided based solely on dimensions.

“For V-belt replacement when the part number is not known, the supplier needs the top width, vertical thickness and length (outside circumference) of the belt. Also, the supplier should be told if the belt is notched, if it’s a single or joined construction and if it’s used on a clutching drive.

“For a synchronous belt replacement, the end-user should provide the belt’s top width, length, number of belt teeth, tooth profile (trapezoidal, round or semi-round) and the body material (synthetic rubber or polyurethane).

“Because they require less maintenance, Gates says synchronous belt systems are often selected to replace roller chain drives. The belt supplier can quickly and easily design a new synchronous belt drive from the following information: required horsepower, shaft diameters, driver and driven speeds, center distance and adjustment range, and size limitations due to the belt drive guard.

“To help an end-user with providing the necessary belt or drive conversion information, Gates created an easy-to- complete worksheet. It can be found at www.gates.com/driveworksheet.”

To learn more about belts, visit www.gates.com.

Subscribe to Machinery Lubrication