The structure of the polyurethane timing belt is composed of a belt back, a tensile layer, and a tooth.
(1) Polyurethane belt back
The back of the timing belt is used to bond and cover the tensile elements. It should have good flexibility and flex fatigue resistance, not easy to age, good oil resistance, wear resistance, and a suitable size of sharpness on the inner surface of the back Angle grooves, in addition to the process requirements, can also improve the flexural fatigue performance of the toothed belt, and at the same time allow the intercepted air between the belt and the gear teeth to escape during operation to eliminate some noise.
(2) Tensile layer of steel rope (or polyester rope)
The tensile layer is the tensile element of the timing belt, which is used to transmit power and ensure that the pitch of the timing belt does not change during operation. It uses multiple strands of steel rope (or polyester rope) to spirally wrap around the width of the tape, and its position is determined as the pitch line of the timing belt. The tensile layer must have high tensile strength and flexural fatigue strength. The elastic modulus is large, and no elongation is allowed during work, so that the pitch of the timing belt is unchanged.
(3) Polyurethane with teeth
The teeth of the polyurethane timing belt should have high shear strength, good abrasion resistance and oil resistance. The requirements for the pitch distribution of the teeth are very high, and the teeth of the belts should mesh correctly with the grooves of the pulleys. Therefore, the accuracy of the geometric parameters of the teeth needs strict requirements.
Polyurethane timing belt is famous for its excellent oil resistance and abrasion resistance. It is suitable for high-speed operation of small and medium power. The environment should be relatively dry. The working temperature is generally -20 ～ + 80 C.