NTN Corporation (hereafter, NTN) has developed the “Hydrodynamic Twin Bearphite” that supports the axis of a motor with a lower torque than conventional bearings, while at the same time delivering outstanding reliability and quiet operation.
NTN has been manufacturing the hydrodynamic Bearphite (sintered metal hydrodynamic bearing Oil-impregnated Sintered Bearing), which features hydrodynamic grooves on the inner diameter sections of the oil-impregnated sintered bearing. The product is widely used in applications such as hard disk drive (HDD) spindle motors and fan motors for cooling electronic equipment due to its high reliability.
Households and offices throughout Japan are currently being called upon to achieve a target 15% reduction in electricity consumption. While consumers demand quieter fan motors used in mobile devices, household electronics and AV equipment, and HDD spindle motors, the more pressing challenge today is reducing the amount of electricity that motors consume during operation.
To produce a lower torque version of the hydrodynamic Bearphite used in motors, the Hydrodynamic Twin Bearphite was developed featuring hydrodynamic bearing surfaces in two areas and a uniquely designed space between them.
The Hydrodynamic Twin Bearphite delivers the same quiet operation and high reliability afforded by the non-contact support characteristic of the hydrodynamic bearing, but reduces bearing torque loss during rotation by approximately 10% by optimizing the design of the large diameter space between the inner diameter surfaces of the bearing. The bearing itself contributes largely to reducing the electrical consumption of motors. Improvements made to the press fit position helps retain the precision of bearing inner surface when the bearing and housing are assembled. This means press fitting can be used for assembly, which is a much simpler process than conventional bonded fitting.
NTN is planning to recommend the Hydrodynamic Twin Bearphite to manufacturers of fan motors and start mass production during 2012. The Hydrodynamic Twin Bearphite will be on display at the 20th Motion & Power Transmission Exhibition held at Tokyo Big Sight between July 20 and 22, with the product expected to be widely used in applications throughout industrial machinery and the automotive industry.
|(1)||10% reduction in rotating torque (compared to conventional products)|
|→||Optimized design of space between the hydrodynamic Bearphite inner diameter surfaces to reduce bearing torque loss when rotating|
|(2)||Outstanding quietness, high reliability|
|→||Non-contact support for the rotational axis with hydrodynamic effects|
|(3)||Simple assembly to housing|
|→||Press fitting possible with large outer diameter surfaces|
Fluid Dynamic Bearing Unit Department, Composite Material Product Division Tel: +81-567-95-5005
|External view of Hydrodynamic Twin Bearphite||Bearing inner diameter surfaces (cut-away model)|