JTEKT Corporation (Headquarters: Kariya City, Aichi Prefecture, President: Yoshito Kondo, hereinafter referred to as "JTEKT") is promoting the improvement of development efficiency in rolling bearing design through model-based development (hereinafter, MBD※1).
Recently, MBD has been dramatically updated to achieve efficiency in the bearing design process utilizing digital technology and improve the reliability of evaluation analysis using new test facilities.
※1 MBD (Model Based Development): A highly efficient development method that drastically shortens the development period and improves product quality by creating a model of the item to be developed and using simulation technology based on that model.
JTEKT aims to become a solution provider that creates the future of the mobility society through manufacturing and production equipment, under the JTEKT Group 2030 Vision. The JTEKT Group is utilizing a technology platform that aggregates competence, which is element technology and knowledge related to products and manufacturing facilities, to propose solutions by combining these competences to address internal and societal challenges, progressing with the establishment of the Solution Co-Creation Center.

The new MBD allows for significant shortening of the design process and minimizes variations in the considerations by designers by introducing a design core system that leverages JTEKT's competence. Additionally, through the newly developed evaluation testing machine using the magnetic bearing, a competence of the group company, evaluations can be conducted at higher rotation speeds than ever before, thus improving the reliability of evaluation analysis.
JTEKT will utilize this MBD to propose solutions such as early product commercialization and enhanced functionality of products.

Shortening the design process through the design core system.

The conventional design process of bearings required the designer to repeatedly perform various technical calculations manually, which resulted in time loss in data transfer and storage, and variability in the designer's considerations became an issue. Therefore, the entire design process was fundamentally reviewed, and a core design system was developed that enables seamless completion from initial considerations to drafting. With the introduction of this system, the design consideration time was reduced to one-fourth of the conventional process, allowing for excellent considerations regardless of the designer's experience.

Improving the reliability of evaluation analysis with a newly developed evaluation testing machine using magnetic bearings.

In the future, as the electrification of automobiles and industrial machinery accelerates, high-speed rotation, efficiency, and reliability requirements for bearings are expected to increase. To design bearings that meet these needs, an evaluation testing machine using magnetic bearings developed and manufactured by the group company, JTEKT Magnetic Bearings, was created. This machine enables performance evaluation under ultra-high-speed rotation and rapid acceleration/deceleration conditions.
Magnetic bearings are bearings that support the rotating shaft via electromagnetic force in a completely contactless manner, featuring zero friction, no need for lubricating oil, and being maintenance-free. The newly developed evaluation testing machine utilizes magnetic bearings in the motor unit that drives the main shaft, allowing evaluation of ultra-high-speed performance, meeting the high-speed rotation requirements of the electric drive system for electric vehicles (BEV) known as eAxle, up to 45,000 min-1 (dmn※2 value 2.7 million). Additionally, for rapid acceleration and deceleration performance, evaluations can be conducted up to 15,000 min-1/s, significantly exceeding market needs. It can also apply loads in both radial and axial directions and supports oil lubrication and grease lubrication.
Using the developed testing machine allows for understanding the limit performance of bearings up to ultra-high-speed ranges that could not be evaluated with conventional high-speed testing machines, making it possible to develop bearings that do not suffer damage or seizure even under high-speed rotation demands for the miniaturization and high power requirements of eAxle. JTEKT is analyzing simulation results in the digital realm and reflecting the gaps with real phenomena into the analysis process, significantly improving reliability.
※2 dmn : A value that expresses the rotational performance of rolling bearings. Pitch circle diameter (mm) of rolling elements × rotational speed (min-1).

Structure and features of the evaluation testing machine using magnetic bearings.

Evaluation capacity of the evaluation testing machine using magnetic bearings.

Based on the results of this demonstration, Hitachi High-Tech and Hitachi will collaborate with various stakeholders such as material manufacturers including Sekisui Chemical to develop a more user-friendly environment and challenge One Hitachi to commercialize services using this system in Fiscal Year 2025. After the service is commercialized, Hitachi High-Tech will use its broad distribution network as a sales agent to expand to domestic and overseas product and material manufacturers. Companies (buyers and sellers) that participate in this business are being asked to join. Hitachi will work with Hitachi High-Tech and Sekisui Chemical to promote system development toward commercialization. Sekisui Chemical will continue to actively promote initiatives toward achieving a circular economy in 2050 by collaborating with Hitachi High-Tech and Hitachi.

By using a revolutionary design core system and evaluation testing machines for high-efficiency and high-reliability MBD, we are continuously working to shorten the design period of bearings and resolve customer issues with minimal lead time. Furthermore, by promoting this MBD, we will also contribute to the realization of a clean carbon neutrality society with zero emissions.
JTEKT will continue to leverage the group's competence to provide optimal solutions to challenges faced by stakeholders, including customers.

Reference

• Press release on January 16, 2023: "Utilizing MBD in the development of 'JTEKT Ultra Compact Bearing.'"
• Press release on December 28, 2021 "Achieving reduced design time and improved performance for rolling bearings through model-based development."