Adjustable Speed Drives
Adjustable speed drives (ASDs) also called variable speed drives (VSDs) describe equipment used to control the speed of machinery. Many industrial processes, such as assembly lines, must operate at different speeds for different products. If a process calls for an adjustment of flow from a pump or fan, adjusting the speed during the process can help save energy.
ASDs are used in a variety of industrial operations and can have ratings from a fraction of a horsepower to thousands of horsepower. Some are based on mechanical techniques and others are based on electrical. Common mechanical drives include belted and traction types. Electrical drives include eddy-current, wound-rotor, induction motor, DC, AC, servo, variable speed, and engineered types.
Adjustable Speed Drives are used for:
- Varying the speed of a motor-driven shaft
- Energy efficiency and money savings
- Gaining a competitive advantage
Adjustable Speed Drives are used when:
- It is more convenient than changing belts
- A slow startup speed is required
- Several finite-operating speeds are required
- Shaft speed needs to remain constant despite different loads
- Overcome high inertia upon startup
- Torque must be held constant with changing shaft speeds
- Two shafts need to be synchronized
- Reduce operating and maintenance costs
- Improve product quality
Content on this page was created using excerpts from the Power Transmission Handbook (5th Edition), which is written and sold by the Power Transmission Distributor’s Association (PTDA). The Power Transmission Handbook is just under 400 pages and is a valuable resource for anyone involved or interested in the power transmission industry.