In the industrial and commercial sectors, one in three electric motors use belt drives. However, some customers fail to take advantage of the potential energy cost savings of certain industrial belts, which are readily available and cost -efficient. While pulleys control the speed of the equipment, industrial belts are designed to position the motor relative to the load. High efficiency and low maintenance are key components to top performing belt transmission systems.
Types of Belt Drives
These are the most commonly used types of belt drives. Using a trapezoidal cross section V-belts create a wedge action on pulleys to increase friction and improve the belt’s power transfer capability.
Heavy loads often require joined or multiple belts. At the time of installation, V-belts have 95% to 98% peak efficiency. Pulley size, driven torque, under or over-belting, and V-belt design and construction impact efficiency. V-belts have a nominal efficiency of 93%, a reduction of 5%, over time if slippage occurs because the belt is not periodically re-tensioned.
These types of belt drives have slots that run perpendicular to the belt’s length, helping to reduce the bending resistance of the belt. While using the same pulleys as v-belts, cogged belts manage to run cooler, last longer, and increase efficiency by 2% from standard v-belts.
This type of belt drive, often referred to as timing belts, boast a 98% efficiency, which is maintained over a wide load range. These toothed belts require the installation of mating tooth-drive sprockets. Synchronous belts require less maintenance and re-tensioning, operate in wet and oily environments and run slip-free. While synchronous belts are the most efficient, they can be noisy, transfer vibrations, and are unsuitable for shock loads. In such applications, cogged belts are the better choice.
Belt Drive Efficiency Calculations: An Example of Potential Savings
A continuously operating, 100-hp, supply-air fan motor (93% efficient) operates at an average load of 75% while consuming 527,000 kWh annually. What are the annual energy and dollar savings if a 93% efficient (η1) v-belt is replaced with a 98% efficient (η2) synchronous belt?
Electricity is priced at $0.06/kWh. Energy Savings = Annual Energy Use x (1 – η1/η2 ) = 527,000 kWh/year x (1 – 93/98) = 26,888 kWh/year
Annual Cost Savings = 26,888 kWh x $0.06/kWh = $1,882
Quick Tips About Belt Drives
- Gather your own data, including operating hours and productivity, of your belt-driven equipment. Determine for yourself if replacing existing v-belts with cogged or synchronous belts and sprockets is a cost-efficient solution for your application.
- Consider cogged or synchronous belts when installing new equipment to increase belt drive efficency. The price premium is minimal compared to the inevitable future costs of conventional pulleys.
A little investment in time to consider whether you're using the right type of industrial belt for the job can have a big payoff in terms of efficiency and maintenance costs.
The product statements contained herein are intended for informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness for a specific application or use. W. W. Grainger, Inc. does not guarantee the result of product operation or assume any liability for personal injury or property damage resulting from the use of such products.
Article and information courtesy of Dayton Manufacturing Company.