JTEKT Corporation (Headquarters: Kariya City, Aichi Prefecture; President: Yoshihito Kondo; hereinafter referred to as "JTEKT") has won the Invention Award in the National Invention Awards for the year of Reiwa 6, sponsored by the Japan Institute of Invention and Innovation, for its patented technology of "Low-powered hydrostatic bearings" used in the grinding wheel shaft of a grinding machine.
Summary of this technology:
A grinding machine is a machine tool that grinds workpieces with a rotating grinding wheel and can achieve excellent dimensional accuracy and surface roughness. Bearings (bearings) that support the grinding wheel shaft of the grinding machine are essential components to ensure stable rotation of the grinding wheel.
In this patented technology, the performance improvement of the "hydrostatic bearings" that support the grinding wheel shaft by applying pressure to the lubricating oil was evaluated. By separating the forward and reverse flows of lubricating oil generated in the bearing during the rotation of the grinding wheel shaft and suppressing the turbulence of the lubricating oil, it was made possible to reduce the power loss (loss of energy due to the flow of lubricating oil) during high-speed rotation by about 20% compared to conventional hydrostatic bearings. This contributes to the reduction of power consumption and CO2 emissions.
Hydrostatic bearings originally have excellent rotational precision and vibration damping properties compared to other methods such as "rolling bearings", and their characteristics of long life span that there is no metal contact part. It was also a major appeal point that energy saving was achieved without impairing these features.
Process of establishing technology:
In recent years, technology has been sought after to reduce the power loss of hydrostatic bearings generated due to the high-speed rotation of the grinding wheel in view of productivity improvement.
JTEKT clarified that the main causes of power loss generated were "interference between flows" and "turbulence of the lubricating oil" within the bearing, through fluid analysis and other procedures. Based on this analytical result, they developed a low-powered hydrostatic bearing that rectifies the flow by separating the forward flow that follows the rotational axis inside the bearing from the reverse flow at the bottom of the bearing and additionally turning that flow into laminar flow.
By incorporating this technology into a grinding machine, it will not only contribute to energy saving, but also suppresses the displacement amount, such as elongation and inclination of parts due to heat, and contributes to the reduction of machine floor space by downsizing the cooling device. Additionally, this technology won the Minister of Education, Culture, Sports, Science and Technology Award at the 2022 Central Japan Invention Awards and the Minister of Economy, Trade and Industry Award at the 2020 Excellent Energy-Saving Equipment and System Awards hosted by the Japan Machinery Federation.
Our grinding machine has won the Minister of Economy, Trade and Industry Award for Excellent Energy-Saving Equipment and Systems.
Won the "Minister of Education, Culture, Sports, Science and Technology Award" at the 2022 Central Japan Invention Awards.
Patent Overview of This Technology:
Patent Registration Number: Patent No. 6455177
Name of the Invention: Hydrostatic fluid bearing device, spindle device for machine tool using hydrostatic fluid bearing device
Going forward
Hydrostatic bearings have been a core technology that JTEKT has been developing for a long time. They will continue to practice efforts to improve product performance in machine tools, such as the low-powered hydrostatic bearing technology in this case. Additionally, in all JTEKT Group products, they strive for environmentally conscious development such as weight reduction, simplification, and downsizing, and contribute to carbon neutrality for customers who use our group's products.