Why Do High-End Automakers All Favor Shaft Forgings?
In automobile manufacturing, shafts are critical transmission components that play a vital role. With the rapid development of high technology, automobiles have become an indispensable means of transportation in modern times. As a core component, shaft forgings, with their advantages of high strength, lightweight, and durability, have become one of the recognized components by various high-end automobile manufacturers. Then, how does this forging provide dual guarantees for safety and performance in the automotive field? What are its specific applications? This article will explore the specific applications and unique advantages of the shaft machined parts provided by Songjie in the automotive field.
I. Automotive Transmission System
The automotive transmission system is the core part of a vehicle’s power transmission, and shaft forgings are key components of this system. They connect the transmission and drive axle, primarily responsible for transferring engine power to the wheels, while withstanding enormous torsional forces and a certain degree of bending forces. “Star products” in this system include drive shafts, half shafts, and gear shafts, among others.
1.1 Drive Shaft
Automotive drive shafts typically adopt hollow shaft forgings. This hollow structure can not only effectively reduce the vehicle weight and improve fuel economy, but also reduce material waste and lower production costs while maintaining high strength. Moreover, through advanced forging processes (or three-roll cross wedge rolling process), the shape and size of the shaft can be more precise, and the density and toughness of the material can be enhanced, thereby meeting the assembly and application requirements. This enables it to effectively reduce energy loss, further improving transmission efficiency and stability, which not only helps enhance the vehicle’s fuel economy but also boosts the vehicle’s acceleration performance.
In addition, drive shaft forgings boast advantages such as excellent fatigue resistance, high torsional strength, good dynamic balance performance, and a long service life. They improve the overall performance of the engine and have become the preferred choice for high-end models.
1.2 Half Shaft (Drive Shaft)
In four-wheel-drive or front-wheel-drive vehicles, the half shaft plays a crucial role in transmitting power from the differential to the driving wheels, serving as the final component in the vehicle’s power output chain. It not only accurately transmits torque but also endures bending stress caused by the vertical movement of the wheels. When faced with complex road conditions and frequent acceleration/deceleration, this shaft exhibits exceptional durability and fatigue resistance. Additionally, the lightweight design of the shaft forging helps improve the vehicle’s fuel economy and handling performance. It also boasts stronger impact resistance, which is pivotal to the “off-road capability” of off-road vehicles and SUVs.
II. Automotive Steering System
This system is crucial to driving safety, and shaft forgings also play an indispensable role in it, acting as the “precision executor” for handling safety, directly related to a vehicle’s “handling performance” and “safety”. Moreover, given the characteristics of new energy vehicles—”fast acceleration and high vehicle weight”—the steering system bears greater loads. The “deformation resistance” of forged shaft components has thus become an important guarantee for safety.
2.1 Steering Shaft
This kind of shaft forging serves as a “bridge” connecting the wheels and the vehicle body. It not only supports the vehicle weight but also cooperates with the steering mechanism to realize wheel deflection, acting as an important component between the steering wheel and the steering gear. Its main function is to directly transmit the torque and angle generated when the driver turns the steering wheel to the steering gear, making it a transitional shaft from “human-machine interaction” to “mechanical execution”.
Generally, our steering shafts are made of high-strength alloy steel (such as 42CrMo). Through integral forging, internal defects are eliminated, and their mechanical properties and durability are enhanced. The shape and size are more precise, reducing the workload of subsequent processing. In addition, their shear strength is 40% higher than that of cast parts, which can effectively prevent fracture during emergency evasion.
III. "Special Requirements" of New Energy Vehicles
With the popularization of new energy vehicles, the application scenarios of shaft forgings are also expanding. Compared with fuel-powered vehicles, new energy vehicles have higher requirements for “lightweight” and “high-speed adaptability” of shaft components.
3.1 Motor Shaft
The rotation speed of a motor is usually 3-5 times that of a fuel engine, thus requiring it to withstand higher centrifugal force. The drive motor shaft is typically made of high-purity alloy steel. Through precision forging and dynamic balance treatment (precision machining), it can maintain stability during high-speed rotation, reduce vibration and noise, and improve the cruising range and power performance of new energy vehicles.
3.2 Reducer Gear Shaft
New energy vehicles have eliminated the transmission, but the gear shaft of the reducer needs to directly bear the high-torque output of the motor, acting as a “wear-resistant pioneer” for efficient transmission. The forging process enhances the tooth root strength of the gear shaft, avoiding the risk of “tooth breakage”. Meanwhile, lightweight designs (such as hollow shaft structures) are adopted to reduce energy consumption. These gear shaft forgings not only need to feature high strength and precision but also possess good corrosion resistance and wear resistance to meet the long-term service requirements of new energy vehicles.
Conclusion
In addition to the above-mentioned shaft forgings, automobiles also use hub shafts, differential gear shafts, camshafts, turbocharger shafts, crankshafts, transmission gear shafts, and so on. At Songjie, we support customization of various shafts, including mechanical shaft forgings in numerous manufacturing fields, special-shaped shafts, machined shafts, etc. We are committed to meeting the needs of more fields and contributing to the development of more manufacturing industries.