How to Choose the Right Timing Belt Tooth Profile

Posted on Aug 16, 2013  | Tags: timing-belt

There are three basic categories for timing belt tooth profiles: Trapezoidal, Curvilinear, and Modified Curvilinear

Trapezoidal Timing Belt Tooth Profiles

Trapezoidal timing belt tooth profiles include the pitches (distance from the center of one tooth to the center of the next tooth) MXL (.08″) , XL (.2″), L (.375″), H (.5″), XH (.875″), XXH (1.125″). LT (.0816″), T2.5 (2.5mm), T5 (5mm), T10 (10mm), AT5 (5mm), AT3 (3mm), and AT10 (10mm). Trapezoidal timing belt profiles excel at registration and are commonly available. L, H, XH, and XXH are readily available in neoprene with fiberglass reinforcements. T2.5, T5, T10, AT3, AT5, and AT10 belts are typically offered in urethane with steel reinforcements. MXL and XL belts are typically offered in neoprene with fiberglass reinforcements, urethane with kevlar reinforcements, or urethane with polyester reinforcements. LT pitch is typically offered in urethane with kevlar reinforcements or urethane with polyester reinforcements.

Curvilinear Trapezoidal Timing Belt Tooth Profiles

Curvilinear timing belt tooth profiles include the HTD profiles. Curvilinear profiles were designed for high torque and high speed applications and are an upgrade over trapezoidal profiles for those applications. They also provide better tracking and less backlash than trapezoidal pitches. HTD profiles are measured in the metric pitch sizes of 3mm, 5mm, 8mm, and 14mm. HTD profiles are typically offered in neoprene with fiberglass reinforcements.

Modified Curvilinear Trapezoidal Timing Belt Tooth Profiles

Modified Curvilinear timing belt tooth profiles include the PowerGrip GT2, Powerhouse™, Poly Chain GT, and Powerhouse MX™. All of these profiles are less prone to backlash. The PowerGrip GT2 and the compatible Powerhouse™ pitch excel at high speed applications and have excellent tracking. They are offered in 2mm, 3mm, 5mm, 8mm, and 14mm pitches and are typically constructed from neoprene with fiberglass reinforcements. The Poly Chain GT and compatible Powerhouse MX™ excel at high torque applications and also have excellent tracking. They are offered in 8mm and 14mm pitches and are typically made from urethane with either kevlar or carbon reinforcements.