NTN Develops World's First Hydraulic Motorcycle Autotensioner, Compact Yet Ideal For High-revving, High Torque Engines

	

NTN Develops World's First Hydraulic Motorcycle Autotensioner, Compact
Yet Ideal For High-revving, High Torque Engines



Tokyo, Japan, Mar. 26, 2004 - (JCN Newswire) - NTN Corporation
has developed the world's first "Hydraulic Motorcycle
Autotensioner". This autotensioner is compact and ideal for motorcycles
with large, high-revving, high torque engines. The autotensioner
maintains the correct amount of tension on the engine timing chain. This
makes the chain last longer and also damps out unnatural engine noises
which occur due to chain vibration.

NTN's hydraulic motorcycle autotensioner employs a hydraulic damper
mechanism, similar to those used in cars, and a relief valve mechanism
that delivers optimal damping force with any variation of chain tension.
Compared to the old mechanical type, this hydraulic autotensioner has
great durability and is ideal even for large motorcycles with 20 percent
higher engine rpm and torque.

Motorcycles typically use a conventional mechanical type autotensioner
that employs a ratchet or friction type mechanism. However, these are
not reliable enough in terms of durability or suppressing resonant
vibrations. In particular, these mechanical autotensioners are a problem
in large sports bikes with big, high-revving, high torque engines. 

NTN's hydraulic motorcycle autotensioner delivers optimal damping force
to the engine chain system even at high engine rpm's and high torque
levels by using a damper regulator mechanism that is controlled by
spring load and relief valve opening pressure. The unit offers superb
durability compared to mechanical actuators because a hydraulic damper
mechanism is employed. 

Sales of four hundred million yen annually are anticipated.


About NTN Corporation

NTN Corporation makes mechanical friction bear-able. The company
manufactures bearings (which range in diameter from one millimeter to
five meters) for use in almost any machine or mechanical system,
including automobiles, jet engines, stereos, computers, and household
appliances. NTN also makes precision processing and automated production
equipment used in the high-tech industry, including CD inspection and
LCD repair systems. The company's automated production equipment
includes bearings, spindles, and positioning tables. NTN also supplies
the automobile industry with constant velocity joints that are used in
four-wheel drive and independent suspension vehicles. About 65% of NTN's
sales are in Asia.For further information, please visit the NTN
Corporation home page at: www.ntn.co.jp <http://www.ntn.co.jp>