Timing Pulleys & Idler Pulley | Single, Double or No Flange Pulleys

A timing pulley is a cogged or cross-tooth pulley with the belt tooth matching the pulley tooth, much like a chain and sprocket. U.S. Rubber developed the first timing pulleys or synchronous pulleys and belts in the 1940s. As the name synchronous implies, timing pulleys were first used to keep two shafts in synchronous. Timing pulleys are designed to fit specific shaft sizes and types, ensuring precise alignment and secure operation. It is in the last 60 years that the timing pulley and belt are considered a positive drive alternative to chain and a replacement for friction drives, such as V-belts.

We at Torque Transmission continue to improve upon this tradition with our time-tested, precise, and reliable timing pulley solutions.

Why Use a Timing Pulley?

Timing belts offer a broad range of innovative drivetrain solutions; these drives employ the positive engagement of two sets of meshing teeth. Hence, no slippage and almost no backlash, maintaining a constant speed ratio, all extremely important in any application and more so in automated machinery requiring indexing or sequencing.

Advantages of timing pulleys:

Timing pulleys with nylon coating or tensioners help protect the belt and drive system from wear and damage.
Timing pulleys provide a safe and reliable solution for power transmission, reducing the risk of slippage and system failure.

Advantages:

Timing Pulleys come with many distinct advantages, such as…

Timing Pulley/Belts are a positive drive for the transfer of rotary mechanical force.
Low backlash drive, high resolution for motion control applications, as well as low maintenance for continuous operations
Positive drive for high torque load transmission applications, giving dependable service life, speed ratios, and low noise.
Efficient operation and repetitive, accurate positioning
Positive drive like a chain but without all the negative attributes of a chain, no lubrication, and quiet
Low-cost and low-mass alternative to a gear train
Positive acceleration and braking, with 99% efficiency
Timing belts do not stretch and require no lubrication.

Types of Timing Pulleys are Defined by Tooth Geometry and Pitch:

Trapezoidal tooth profile with pitch measured in inches.
MXL (0.080), XL (0.200), L (0.500)
Low cost
Very good positioning accuracy
Curvilinear tooth profile with pitch measured in millimeters.
HTD 3mm, 5mm, 8mm
GT3 2mm, 3mm, 5mm
Higher torque load per centimeter of belt width
Greater positioning accuracy

Note: Some profiles, such as FHT®, are to be discontinued and may not be available in the future.
Pulleys and belts can also be cut to custom widths or diameters to meet specific application requirements.

graphs

Trapezoidal Tooth Profile Curvilinear Tooth Profile

Timing Pulley Applications

Timing pulleys play a critical role in applications where precise power transmission and synchronization are essential. Working seamlessly with timing belts, they ensure accurate motion control while minimizing slippage and maintenance issues.

Tooth Profiles for Specific Applications

The tooth shape determines belt compatibility and performance.

Curvilinear profiles (GT2, GT3, HTD): Ideal for high-torque or high-speed systems requiring frequent reversals or precision positioning.
Trapezoidal profiles (XL, L, T): Reliable for continuous, high-speed conveying systems where consistent performance is key.

Material Selection and Performance

Selecting the right material enhances system efficiency and durability:

Aluminum: Lightweight, corrosion-resistant, and ideal where weight reduction matters.
Steel: Offers maximum strength and longevity under heavy loads.
Nylon or Polyurethane: Quieter and more flexible for sound-sensitive or light-load environments.

Supporting Components for Extended Life

Flanges and idlers are essential for maintaining belt alignment and tension. Flanges secure engagement between the belt and pulley, while idlers guide the belt and reduce wear—both extending system life and reliability.

Selecting the Right Pulley

Choosing the correct timing pulley depends on load, speed, and system layout. With a broad range of sizes, materials, and tooth configurations available, selecting the optimal pulley ensures efficient, dependable performance across your power transmission applications.

Torque Transmission's Timing Pulleys

XL 0.200 pitch
L 0.500 pitch
3mm HTD
5mm HTD
8mm HTD
GT3
- 2mm pitch
- 3mm pitch
- 5mm pitch

These timing pulley products are sold in a variety of sizes and configurations to meet different application needs. All products are designed for reliable performance in a wide range of drive systems. Customers can request custom bore sizes, modifications, or quotes for specific timing pulley products.

Torque Transmission-Your Timing Pulley Supplier

At Torque Transmission, we understand the importance of precise and reliable power transmission in your systems. All our product’s profiles, widths, and pitch diameters align with MPTA and ARPM Standards.

Together, we can identify your timing pulley needs and then create tailored solutions to meet them. For easier product selection, you can also watch our video tutorial on how to use the timing pulley selector tool.