# Calculation and Selection of Synchronous Belts and Pulleys

Synchronous belt transmission is a cutting-edge transmission method that utilizes the interlocking of belt teeth to transmit power.

It boasts precise synchronous transmission, requires no lubrication, prevents slippage, is eco-friendly, and operates with minimal noise.

Its transmission efficiency is impressive, reaching 0.98, and the speed ratio can range from 1:10. The maximum line speed is 50M/s, and the transmission rate can range from hundreds of watts to hundreds of kilowatts, making it suitable for multi-shaft transmission.

Synchronous belt transmission is widely used in a variety of industries, including textiles, automobiles, chemical fibers, cigarette production, papermaking, printing, and chemicals.

In recent years, there has been a growing demand for its use in the mining, metallurgy, steel machinery, and medical equipment industries.

## 1. Selection and calculation of vertical synchronous belt and pulley:

Design Requirements for Vertical Direction: The total weight of the tray and its contents is 20 kilograms (196 Newtons), and it takes 6 seconds for the slider to travel a distance of 1250 millimeters.

### 1. Design power

Check the table according to the working conditions and take Ka = 1.5

### 2. Belt type selection

According to

And pulley speed

Select 5m arc belt after checking the table.

### 3. Number Z and pitch diameter of belt teeth

According to the belt speed and installation size, it is advisable to choose the larger value as much as possible. After referring to the table, a 5M belt with 26 teeth and a pitch diameter was selected.

Diameter of outer circle

### 5. Transmission ratio

The driving and driven pulleys are consistent, the transmission ratio is I = 1, and the driving and driven pulleys are of the same model.

Check the table

### 11. Setting of retaining ring

5m pulley, minimum height of retaining ring k = 2.5 ~ 3.5, r = 1.5, thickness of retaining ring t = 1.5 ~ 2

Diameter of the bend of the retaining ring

Outer diameter of retaining ring

Vertical synchronous pulley:

• Pulley Type: Circular Arc Tooth with 5m
• Pitch Pitch Diameter: 41.38mm
• Number of Teeth: 26
• Outer Diameter: 40.24mm
• Total Pulley Width: 13.3mm
• Outer Diameter of Retaining Ring: 48.24mm
• Pulley Hole Diameter: 10mm
• Fixing Method: Set Screw (Side Fixing with Table Width of 7mm and Threaded Hole of M3, Secured with Two Screws at 90 Degrees)

Vertical synchronous belt:

Belt type 5m arc belt, with a bandwidth of 10.3mm and a pitch length of about 3418mm

## Selection of synchronous pulley

The following parameters require attention when selecting a synchronous pulley: tooth shape, number of teeth, material and surface finish, and pulley shape.

## 1. Tooth shape

The tooth shape of synchronous belts can be categorized into several types: English (Ordinary Torque) MXL, XL, L, H; Metric (High Torque) S2M, S3M, S4M, S5M, S8M; and (Ordinary Torque) T5 and T10.

When selecting the tooth shape, refer to the following table for guidance.

Simple type selection table 1 (MXL, XL, L, H, T5, T10)

Simple type selection table 2 (S*M)

## 2. Number of teeth

The number of teeth is an important parameter of the synchronous belt pulley.

The pitch diameter of the synchronous belt pulley = the number of teeth × Pitch / π

## 3. Material and surface treatment

The common materials of synchronous pulley are aluminum alloy and 45 steel, and the surface treatment is:

## 4. Pulley shape

K-wheel

A-wheel

B-wheel

D-wheel

Specification of belt axle hole: