Timing (synchronous) belts mate with same-pitch timing pulleys in power transmission systems in which maintenance of speed ratio is an important design consideration. A timing pulley transmits force to the belt via evenly spaced grooves, which mate with the teeth in the belt. These same grooves and teeth prevent belt slippage. Synchronous belt drives are highly efficient. The belts come in a wide variety of materials and reinforcement materials. Imperial pitch timing belts have a trapezoidal tooth form whose spacing (pitch) is based on inch measurements.
ANSI pitch is the most important specification to consider when searching for timing belts, English pitch. Pitch is the distance from one tooth center to the adjacent tooth center; English or Imperial pitch is also referred to as "H-Pitch". Choices for pitch include 0.080" (MXL), 0.0816" (40 DP), 0.200" (XL), 0.375" (L), 0.500" (H), 0.875" (XH), and .250" (XXH). The geometry of the belt is also important to consider. Belt width, number of teeth, and length are the most important geometry parameters. For a given pitch, a selected number of teeth will determine the belt length. Likewise, a specified belt length will determine the number of teeth.
Timing (synchronous) belts mate with same-pitch timing pulleys in power transmission systems in which maintenance of speed ratio is an important design consideration. A timing pulley transmits force to the belt via evenly spaced grooves, which mate with the teeth in the belt. These same grooves and teeth prevent belt slippage. Synchronous belt drives are highly efficient. The belts come in a wide variety of materials and reinforcement materials. Imperial pitch timing belts have a trapezoidal tooth form whose spacing (pitch) is based on inch measurements.
ANSI pitch is the most important specification to consider when searching for timing belts, English pitch. Pitch is the distance from one tooth center to the adjacent tooth center; English or Imperial pitch is also referred to as "H-Pitch". Choices for pitch include 0.080" (MXL), 0.0816" (40 DP), 0.200" (XL), 0.375" (L), 0.500" (H), 0.875" (XH), and .250" (XXH). The geometry of the belt is also important to consider. Belt width, number of teeth, and length are the most important geometry parameters. For a given pitch, a selected number of teeth will determine the belt length. Likewise, a specified belt length will determine the number of teeth.
Belt material choices for timing belts, English pitch include Neoprene, polyurethane, rubber, and urethane. Belt material selection factors may include operating tension, environmental factors such as humidity and temperature, and power transmission. Consult belt manufacturer to optimize material selection. Many timing belts are reinforced with fibers or cables in the tension area of the belt. Reinforcement can significantly enhance the maximum operating tension of a belt. Metallic and non-metallic reinforcement fibers are available. Consult manufacturer on a specific application for best selection of reinforcement material. Common materials for reinforcement include fiberglass, Kevlar, polyester, and steel.
Performance specifications to consider when specifying timing belts, English pitch include ultimate tensile strength, maximum operating speed, and operating temperature. The ultimate tensile strength is the breaking strength or tension rating. Many belts are rated for a maximum operating speed. This is dependent on material and belt geometry. The operating temperature is the temperature range over which the device must operate. Common features for timing belts, English pitch include double sided, truly endless, and open-ended. Double-sided belts have teeth on both sides of belt. Truly endless belts are manufactured as one closed loop; not spliced. Open-ended belts comes in a roll and may be cut and spliced to desired length and number of teeth.
