Product-related Initiatives for the Environment  Back Number (2011)

Bearings are a fundamental industrial product that is indispensible for humanity. Bearings enable parts to move easily and rotate smoothly. They improve functioning, conserve energy, and enable devices to be made smaller and last longer.

The Minebea Group boasts the top share in two opposing segments of the market: that for miniature ball bearings with a outer diameter of 22mm or less, and that for rod ends and spherical bearings for the aviation industry.

However, for both types of bearings, users demand extremely high levels of precision and product quality. To enhance these attributes of our bearings even further, we must push the limits of technology for such product attributes as outer and inner race groove roundness, ball sphericity, and the material quality of constituent parts.

Using our proprietary production equipment, maintenance technology, production line architecture and other expertise embodying 60 years of accumulated knowhow, the Minebea Group produces all of its bearing components in-house, and has never stopped pursuing ever-higher precision and product quality.

These highly precise, quality bearings are incorporated in home appliances, telecommunications equipment, automobiles and other products that play an integral role in our daily lives, and their high precision, extended service life, resource- and energy-efficiency and other characteristics are contributing to the environment in all kinds of ways.

A wide range of home appliances and office products, including televisions, air conditioners, PCs, and printers, operate by converting alternating (AC) mains current to direct current (DC) with an internal AC-DC converter. However, it is difficult to achieve 100% AC-DC conversion, and all of the current that cannot be converted to DC is radiated as heat.

Conventional AC-DC converters operating with an input voltage of 100 volts require two or three heat sinks affixed to the circuit board to dissipate heat into the air, because conversion efficiency is in the 87-90% range.

However, the new dual-boost LLC-type AC-DC converter developed by the Minebea Group achieves 93% efficiency with 100-volt input and 94% efficiency with 200-volt input without the need for heat sinks. Consequently, it was possible to reduce the height of the new converter board to 10 millimeters and reduce the number of parts required.

This newly developed AC-DC converter is expected to become a core energy-efficiency product for such applications as large flat-panel televisions and data center servers.

In FY2010, the Minebea Group began mass production of a brushless DC motor incorporating internal drive and control circuits.

Compared to DC motors that employ brushes to control the direction of current, the new DC motor consumes less power, is more efficient, and has a longer service life. The use of neodymium magnets and ball bearings developed by Minebea enhanced the motor's output characteristics. These motors are already being used in heliostat drive mechanisms for concentrated solar power systems, a potentially important next-generation source of electric power.

Furthermore, while DC motors using brushes have a power efficiency of 40-50%, brushless DC motors boast an efficiency of approximately 70%. Since it is estimated that more than half of all electricity consumed in machine operation is used to drive motors, demand for DC brushless motors is expected to increase in part due to their energy efficiency.

The Minebea Group has commercialized a series of weather-resistant, oil- and dust-proof AC fan motors with long service lives for products used in harsh environments, such as machine tools, and for such outdoor products as solar light generation systems and electric vehicle rechargers.

Enhancing weather resistance in all kinds of environments, this series saves user time and trouble required for maintenance while contributing to lower life cycle costs.