The structure of polyurethane timing belt consists of three parts: belt back, tensile layer (steel core or Kevlar core), and belt teeth.
(1) The back of the polyurethane belt backing timing belt is used to bond and wrap the tensile element. It should have good flexibility and flex fatigue resistance, not easy to age, good oil resistance, and abrasion resistance, on the inner surface of the belt back A sharp-angled groove with an appropriate size can not only improve the flexural fatigue performance of the toothed belt due to process requirements, but also allow the intercepted air between the belt and the gear teeth to escape during operation to eliminate part of the noise.
(2) Steel wire rope (or Kevlar wire rope) Tensile layer 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 remains unchanged during operation. It uses multi-strand steel wire rope (or Kevlar wire rope) to spirally wind the cloth along the width of the tape, and its position is set as the pitch line of the timing belt. The tensile layer must have high tensile strength and bending fatigue strength. The elastic modulus is large, and no elongation is allowed during work, so as to ensure that the pitch of the timing belt remains unchanged.
(3) Polyurethane belt teeth Introduction Polyurethane timing belt teeth have high shear strength, good wear resistance and oil resistance. The pitch distribution of the belt teeth is required to be very high, and the belt teeth mesh with the tooth groove of the belt wheel correctly. Therefore, the correctness of the geometric parameters of the belt teeth must be strictly required.
Polyurethane timing belt is known for its excellent oil resistance and abrasion resistance. It is suitable for high-speed operation of medium and small power. The environment should be relatively dry. The ideal working temperature is generally -20～+80 C.
●Most of the rubber timing belt is composed of four parts, namely: glass fiber tensile layer, neoprene tape back, neoprene tape teeth and nylon cloth layer. The following is a detailed introduction to these four components:
(1) Glass fiber tensile layer
The glass fiber tensile layer is a rope composed of multiple strands of glass fiber, which is spirally wound at the pitch line of the tape along the width of the tape. It has high strength, small elongation, corrosion resistance and good heat resistance.
(2) Neoprene tape back
The neoprene tape back firmly adheres the glass fiber to the pitch line, and plays the role of protecting the tensile material. When the belt back is used in the transmission, it can prevent the damage caused by friction. It is better than the polyurethane timing belt The wheel back has superior hydrolysis resistance and heat resistance.
(3) Neoprene tape teeth
The belt teeth are made of neoprene with high shear strength and appropriate hardness. They need precise molding and precise distribution to properly mesh with the tooth grooves of the pulley. The tooth roots must maintain a specified distance from the pitch line. No change.
(4) Nylon cloth layer
The nylon cloth layer is the anti-friction part of the protective tape. It should have excellent wear resistance and is composed of nylon cloth with a small friction coefficient.
The rubber timing belt has the characteristics of dynamic bending, anti-cracking, good performance, excellent ozone performance, aging resistance, heat resistance, oil resistance, abrasion resistance, etc., so it is widely used.
