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 designed for durability and consistent performance. They are used in applications that require precise speed control and long service life.

At the core of each pulley are movable flanges, typically made from:

• Cast iron
• Aluminum

Material Options

Cast Iron Pulleys

• High strength and wear resistance
• Stable under heavy loads
• Suitable for continuous-duty applications
• Ideal for demanding industrial environments

Aluminum Pulleys

• Lower weight reduces system mass
• Improved heat dissipation
• Supports longer belt life
• Performs well in high-speed or elevated temperature conditions

The material selection depends on application requirements—whether priority is strength and load capacity or weight reduction and thermal performance.

System Integration and Adjustability

Each variable speed pulley mounts securely to the driven shaft and operates with the motor to provide a continuous range of speed adjustment within defined ratio limits.

Key system features include:

• Adjustable motor bases for quick speed changes
• Ability to adapt to changing loads and operating conditions
• Consistent performance across varying speed ranges

This adjustability is critical in applications where operating conditions change frequently.

Belt Interaction and Wear Control

The belt is a critical component of the system. It is designed to work with the pulley to deliver smooth speed transitions and controlled power transfer.

Benefits of proper belt and pulley design:

• Reduced friction and wear
• Improved efficiency
• Extended service life
• Lower maintenance requirements

Accessories and Customization Options

A full range of components is available to support system performance and customization:

• Sheaves
• Adjustable motor bases
• Mounting hardware

Both standard and custom configurations are available. This allows for:

• Replacement of existing or discontinued components
• Optimization for unique application requirements

Engineering Support and Selection

Torque Transmission provides guidance to help select the correct pulley system based on application needs. Support includes:

• Product selection assistance
• Installation and adjustment guidance
• Access to specifications and technical resources

With decades of experience in variable speed drive systems, our team focuses on delivering reliable performance, extended service life, and efficient operation, contact us today.

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