40Cr Cylindrical Gear Helical Gear For Gearbox And Machine Tools

40Cr Cylindrical Gear Helical Gear For Gearbox And Machine Tools

It has good mechanical properties, suitable for medium load and speed applications. 

Characters of Cylindrical Gear Helical Gear:

1. Helical gear transmission is basically the same as spur gear transmission. The main difference is that helical gears have a helix angle β. This angle has a direct impact on the axial force Fa, and Fa is proportional to tgβ.
2. In order to prevent the bearing from being subjected to excessive axial force, the helix angle β of the helical cylindrical gear should not be too large. However, if β is too small, the characteristics of the helical gear will not be so obvious. Usually, the value range of β is 8°~20°, and 8°~15° is commonly used. In some designs, β tends to increase, and some even reach 25°.

Heat treatment characteristics of 40Cr steel:
1. 40Cr steel is a medium carbon alloy steel, suitable for manufacturing mechanical parts that bear medium loads and work at medium speeds, such as gears, shafts, worms, etc. on machine tools.
2. The heat treatment process of 40Cr steel includes annealing, normalizing, quenching, tempering and tempering, which are essential to ensure the performance of the gear. The design of the heat treatment process needs to be different according to the specific application and working conditions of the gear.

3. Normalizing is part of the preliminary heat treatment, and the heating temperature is usually 30 to 50 degrees above Ac3 (the critical temperature of steel). For medium carbon alloy steel, the normalizing temperature is usually 50 to 100 degrees above Ac3, and the specific temperature range is about 850 to 900 degrees. The quenching and tempering process is used to increase the hardness and strength of the steel while maintaining a certain ductility.

Gear design elements:
When designing a gear, multiple factors need to be considered, including tooth shape, module, pressure angle, tooth top height, tooth root height, number of teeth, etc. Among them, the pressure angle is an important parameter, which determines the inclination angle of the gear tooth relative to the normal of the reference line. Generally, a 20-degree pressure angle is used, but other values ​​can also be selected according to specific applications. The larger the pressure angle value, the wider the tooth root will be, which is beneficial to the improvement of gear strength.

Selection of module:
Module is the basic element that indicates the size of gear teeth. The choice of module depends on the load and rotation speed of the gear. Generally speaking, the greater the load and the faster the rotation speed of the gear, the larger the module needs to be designed to enhance the strength of the gear. There are standard values ​​for the module, and the appropriate module can be selected according to the specific application and requirements.

40Cr Spiral Bevel Gear Parameters:

About us: 

1. Our company was formerly known as Changsha Double Star Gear Industrial Co., Ltd., which was established in 1994. It is a directly affiliated school-run enterprise founded by Professor Zeng Tao of Central South University, an authoritative expert on spiral bevel gears in China.