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The eBearing News
November 29, 2005
NTN Develops Intelligent
Wheel Hub Bearing / CV Unit
copyright © 2005 eBearing Inc.
NTN Corp. (Japan; TSE:
6472) announced it has
developed a unitized wheel bearing hub unit with integral constant velocity joint;
in addition, the assembly incorporates advanced force detection sensors.
The "intelligent axle unit" provides instantaneous measurement of a vehicle's speed,
traction force and cornering force. The sensors allow for the development of more
accurate and faster-responding vehicle stability control systems.
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| (courtesy NTN) |
Electronic vehicle stability control (VSC) systems are increasingly available on passenger cars
and trucks, helping prevent excessive slipping or skidding in corners, sliding on slippery
surfaces, or loss of control during abrupt maneuvers.
In the wheel hub bearing unit, sensors detect the small deflections and distortions caused
when the unit is subjected to cornering forces. Sensors in the CV joint detect similar
deflections caused by driving torque. Together, the sensors give a picture of how the
vehicle, tires, and road are interacting.
NTN said vehicle stability control systems currently in use are limited by the fact that
the sensors measuring cornering and braking forces are often measuring secondary or tertiary
effects -- throttle position, or vehicle speed via yaw rate or lateral acceleration sensors,
for example. However, NTN argues, those chassis-mounted sensors are compromised by their location
being isolated by the vehicle's entire suspension system. As a result, those sensors necessarily
suffer from a significant time lag from when the vehicle interacts with the road and the
motion is carried through the vehicle's suspension and chassis to the sensors.
By moving the sensors to where they are most directly in contact with the tires and the road,
information about the vehicle's interaction with the road is measured virtually instantaneously
and without the chassis/suspension damping effects.
The result is faster, higher quality information available to the vehicle's stability
control system. In addition, by incorporating the sensors at every wheel location rather
than at just one central location, more data is available which allows even more precise
and immediate control of the VSC system.
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| (illustrations courtesy NTN) |
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- by Bruce A. Carr
from individual research,
tips and commercial sources.
Unauthorized reproduction is prohibited.
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Entire contents Copyright 1999-2008, eBearing Inc. All rights reserved.
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eBearing.com ... for everything that moves™
Entire contents Copyright © 1999-2008, eBearing Inc. All rights reserved.
eBearing.com and "... for everything that moves" are registered trademarks of eBearing Inc.
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