Timing belts combine the characteristics of belt drive and chain drive Composed of strong layer 1, toothed belt 2, and back belt 3.

1. Advantages of Timng belt drive:

(1) No relative sliding, constant belt length, stable transmission ratio;

(2) Thin and lightweight, with high strength layer, suitable for high-speed transmission, with a speed of up to 40 m/s;

(3) The flexibility of the belt is good, and smaller diameter pulleys can be used. The transmission structure is compact and can achieve a larger transmission ratio;

(4) The transmission efficiency is high, reaching 0.98-0.99, making it increasingly widely used;

(5) The initial tension is small, so the load on the shaft and bearings is small

2. Disadvantages of Timing belt drive:

Manufacturing and installation require high precision and high cost

3. The purpose of Timing belt drive:

Mainly used in medium and low-power transmissions that require accurate transmission ratios, such as computers, recorders, grinders, and textile machinery.

4.Parameters, types, dimensions, and markings of synchronous belts

4.1. Parameters of synchronous belt: 

(1) Pitch pb

(2) Modulus m: m=pb/T

4.2. Types and sizes of Timing belts

The working tooth surface of a Timing belt is divided into two categories: trapezoidal teeth and arc teeth .Timing belts have both single-sided and double-sided structures. The toothed arrangement of double-sided tape is divided into two forms: DA type and DB type In addition, there are special structured synchronous belts used for special purposes.