Automobile transmission shaft is one of the parts, which can be said to be a device for transmitting power. The function of the transmission shaft is to transmit the power of the gearbox to the driving wheels to make the vehicle move forward or backward normally. If it is damaged, there will be sudden acceleration or abnormal sound.

 

Materials of automobile transmission shaft -- Introduction

 

The commonly used materials of shaft parts are 35, 45 and 50 high-quality carbon steel, of which 45 steel is the most widely used. Ordinary carbon steels such as Q235 and q255 can also be used for shafts with small load or less important. Alloy steel can be used for those with large stress, limited axial size and weight, or some special requirements. For example, 40Cr alloy steel can be used in the workplace with medium precision and high speed, and the material has better comprehensive mechanical properties after quenching and tempering treatment; Cr15, 65Mn and other alloy steels can be used in the situation of high precision and poor working conditions. These materials have good wear resistance and fatigue strength after quenching, tempering and surface quenching; For shaft parts working under high-speed and heavy load conditions, 20Cr, 20CrMnTi, 20mn2b and other low-carbon steels or 38CrMoA1A carburized steels are selected. After carburizing, quenching or nitriding treatment, these steels not only have high surface hardness, but also greatly improve their core strength, so they have good wear resistance, impact toughness and fatigue strength. Nodular cast iron and high strength cast iron are often used in manufacturing shafts with complex shape and structure because of their good casting performance and vibration damping performance. In particular, the rare earth magnesium nodular cast iron developed in China has good impact toughness, friction reduction, vibration absorption and low sensitivity to stress concentration. It has been used to manufacture important shaft parts in automobiles, tractors and machine tools.

 

Material composition of automobile transmission shaft

 

Automobile transmission shaft is composed of shaft tube, telescopic sleeve and universal joint. The telescopic sleeve can automatically adjust the change of the distance between the transmission and the drive axle. The universal joint ensures the change of the included angle between the output shaft of the transmission and the input shaft of the drive axle, and realizes the constant angular speed transmission of the two shafts. Generally, the universal joint is composed of a cross shaft, a cross bearing and a flange fork. The universal joint of transmission shaft used by Steyr series heavy trucks adopts roller cross shaft bearing and short and thick cross shaft, which can transmit large torque. A butterfly spring is arranged on the end face of the bearing to compress the roller. Reinforced nylon gasket with spiral groove is added to the end face of the cross shaft to prevent sintering when transmitting power with large included angle or large torque.

 

A tubular sealing protective sleeve is added outside the flange spline shaft of the automobile transmission shaft, and two polyurethane rubber oil seals are set at the end of the protective sleeve, so that a completely sealed space is formed in the telescopic sleeve, so that the telescopic spline shaft is not eroded by external sand and dust, which is not only dust-proof but also rust proof. Therefore, applying grease in the spline shaft and sleeve at one time during assembly can fully meet the use requirements, there is no need to install oil nozzle for lubrication, and the maintenance content is reduced.

 

Material of automobile transmission shaft -- structural characteristics of automobile transmission shaft

 

The vehicle selects different types of transmission shafts according to different driving forms, 4 × 2. The vehicle in the form of drive has only one main transmission shaft, 6 × 4. Vehicles in the form of drive include intermediate transmission shaft, main transmission shaft, middle and rear axle transmission shaft, 6 × 6. The vehicle with driving form has not only the middle transmission shaft, main transmission shaft, middle and rear axle transmission shaft, but also the front axle drive transmission shaft. The middle transmission shaft of the vehicle with long wheelbase is generally provided with the middle support of the transmission shaft, which is composed of support frame, bearing and rubber support.