The impact of CVJs on vehicle quietness and ride comfort can be evaluated as early as the design phase

R&D hours reduced by up to 8%

 

NTN Corporation (hereinafter referred to as NTN) has developed a vehicle-level simulation and analysis technology capable of predicting the impact of constant-velocity joints (CVJs)—core components that transmit drive power from the vehicle’s motor or engine to the tires—on vehicle vibration during operation.

Using this technology, the impact of CVJs on vehicle vibration characteristics can be understood as early as the design phase, enabling the development of optimal new products tailored to specific vehicle performance requirements. At the same time, it reduces the man-hours required for prototype manufacturing and real-vehicle evaluation, accelerates the R&D of high-value-added products, and contributes to the creation of vehicles with excellent quietness and ride comfort.

 

In recent years, with the growing popularity of electric vehicles such as hybrid electric vehicles (HEVs) and battery electric vehicles (BEVs), noise and vibration generated by the engine have been significantly reduced. Vehicle body vibrations and noises that were previously difficult to detect have become more noticeable, and market demands for NVH (Noise, Vibration, and Harshness) performance—including interior quietness and driving experience—continue to rise.

Furthermore, the layout of the entire vehicle—including the powertrain and chassis—is becoming increasingly diverse, and automakers are seeking solutions tailored to their unique vibration characteristics. At the same time, the demand for shorter development cycles and improved development efficiency continues to grow, making it increasingly important to predict actual in-vehicle performance during the early design stages of component development.

 

Among the various types of CVJ products, the three-pin sliding CVJ—primarily used on the differential side—is structurally designed to follow the movement of the suspension to transmit power. During operation, internal friction within the universal joint generates minute axial forces (induced forces), which are transmitted to the vehicle body and may cause vehicle vibration, thereby affecting the ride experience. However, in the early stages of CVJ development, it has traditionally been difficult to predict the actual performance of components once installed in the vehicle, making it necessary to rely on repeated in-vehicle testing for validation.

 

To address these challenges, NTN has developed a vehicle vibration prediction simulation model that integrates CVJ mechanism simulation technology with vibration transmission path analysis (TPA) technology.

By optimizing the CVJ simulation model developed over many years, the system achieves high-precision reproduction of induced forces under driving conditions. Furthermore, by accounting for differences in the transmission characteristics of individual components, the model analyzes the entire process by which vibrations travel from the CVJ through the engine, electric drive unit (e-Axle), suspension, and vehicle frame into the passenger compartment, thereby enabling highly accurate prediction of vehicle vibration during operation.

 

Based on this technology, it is possible to understand vibration transmission paths and modes, enabling the evaluation of actual in-vehicle performance as early as the CVJ design phase. Verification can be conducted in the early stages of development, facilitating the development of optimal products tailored to the vehicle’s characteristics. Furthermore, vehicle vibrations can be predicted without the need for prototype parts or real-vehicle testing, which is expected to reduce development man-hours by up to approximately 8% compared to traditional methods.

 

In the future, NTN will use this technology to expand its database of vibration characteristics for various vehicle models, with the goal of establishing a new development process that significantly reduces the need for real-vehicle testing.

 

NTN will continue to refine the low-vibration and high-quietness performance of its CVJs and strengthen customized solutions tailored to various vehicle operating conditions. The company will accelerate the research and development of next-generation mobility products, including electric vehicles such as HEVs and BEVs, contributing to the creation of a comfortable and pleasant mobility society.

 

 

NTN Three-Pins Mobile Constant-Velocity Joint “PTJ”

NTN’s

“Cyber Agile Engineering”

(Digital Agile Engineering)

 

 

NTN is vigorously promoting Cyber Agile Engineering, actively utilizing digital technologies such as simulation and data analysis in the R&D phase to accelerate the development process.

 

By integrating AI technology to enhance design, simulation, and evaluation capabilities in a digital virtual space, NTN is gradually establishing a development process that does not rely on prototype manufacturing or real-vehicle testing, thereby shortening development cycles and improving R&D efficiency. The CVJ analysis technology introduced here is a direct result of this initiative.

 

Moving forward, NTN will further advance the use of digital technologies to empower R&D, enhance its capabilities in developing high-value-added products, ensure timely product launches, and contribute to the realization of a next-generation mobility society.