VPS Variable speed Pulleys

Variable Speed Pulley (VPS) Dimensions ** Click on Desired Variable Speed Pulley for Detailed Technical Information* Model A B C1 Open C2 Closed D Dia. Standard Bores 3/8 1/2 5/8 10mm 12mm 16mm VPS-15 2-5/8 9/16 3/4 7/16 2-7/8 • •   • •   VPS-20 3   7/8 1/2 3-1/2   • •   • • Non-Standard Bore sizes, both Inch and Metric are available upon request at no extra charge.  Please contact us.

Variable Speed Pulleys are shipped with the blue, heavy strength spring unless another strength spring is requested.

Torque Transmission is an ISO Certified company.

Speed range is infinitely variable within standard ratio limits. All of our variable speed pulleys are color-coded to indicate spring pressure - easy to identify and use.

Standard bores range from 3/8" to 5/8" in hex shaft design. These pulleys combine strength and cost savings of a steel hub and mounting shaft; the pulley flanges are a combination of glass-reinforced nylon and steel pulley face.

Designed for belt sizes from 3/8" V to 1/2" V and horsepower ratings up to 1/2 HP, including fractional horsepower ratings for smaller or more precise applications, they are engineered to offer an economical alternative for many applications that may not require the expense of AC/DC variable speed motors and drives.

Simple belt tensioning adjustments allow for speed changes from 2.45:1 up to 2.8:1. This speed change mechanism enables the rotational speed of the driven shaft to be increased or decreased as needed. The RPM (revolutions per minute) of the shaft can be decreased to match specific application requirements, providing flexibility for efficiency. The pulley system allows for precise adjustment of revolutions per minute (RPM) to optimize performance for various load conditions.

• Economical
• Lightweight
• Strong
• Quiet
• Infinite speed range - within pulley’s ratio limits

Speed adjustments can be made over time to accommodate changing load and application conditions, ensuring optimal performance and efficiency.

Standard variable speed pulley sizes and types, dimensions and spring pressures are listed below.

Standard Tolerances for Bore Sizes, Keyways and Setscrews

To learn more about the benefits and features of our variable speed pulleys, please explore the provided links or contact us for additional information.

Construction and Materials

Variable speed pulleys are engineered with durability and performance in mind, making them a reliable choice for many applications that demand precise speed control and long service life. The core of every variable speed pulley is its set of movable flanges, which are most commonly crafted from high-quality cast iron or aluminum. Cast iron pulleys are favored for their exceptional strength and resistance to wear, providing enhanced security and stability in heavy-duty environments. This makes them ideal for applications where the drive system is subject to high loads or continuous operation.

On the other hand, aluminum pulleys offer a significant decrease in weight, which can be a major benefit in applications where reducing the overall mass of the drive is important. Aluminum’s superior heat dissipation properties also contribute to longer belt life and improved efficiency, especially in high-speed or high-temperature environments. The choice between cast iron and aluminum depends on the specific requirements of your application—whether you need increased strength and security or the benefits of a lighter, more thermally efficient design.

Each variable speed pulley is mounted securely on the driven shaft and works in tandem with the motor to deliver an infinite range of speed adjustments within the standard ratio limits. Adjustable motor bases are a key accessory, allowing for quick and easy changes to the speed range as operational needs evolve. This adjustability is especially valuable in applications where frequent speed changes are necessary, ensuring that your drive system can adapt to varying loads and process requirements.

The belt, another critical component, is designed to work seamlessly with the pulley to provide smooth, efficient speed changes and minimize wear. High-quality materials and precision engineering in both the belt and pulley construction help extend the service life of the entire drive system, reducing maintenance needs and downtime.

In addition to the pulleys themselves, a full range of accessories—including sheaves, adjustable motor bases, and mounting hardware—are available to help you customize your drive for optimal performance. Our extensive stock includes both standard and custom items, so whether you’re looking to choose a new speed pulley for a unique application or need to replace a discontinued item, we can help you find the right solution.

For more information, detailed specifications, or to view instructional videos on installation and adjustment, please contact our team. With decades of experience in variable speed drives, we offer expert guidance to help you select the best products for your application. Trust our commitment to quality and customer service to deliver increased benefits, longer service life, and a drive system designed to work efficiently for your needs.

Standard variable speed pulley sizes and types, dimensions and spring pressures are listed below.