High efficiency hydraulic mechanical automatic transmission “Hondamatic” featuring excellent drivability
The HMT (hydraulic mechanical transmission) was born from the research and development of high performance automatic transmission for motorcycles. Honda has continued the research and development of the infinitely variable transmission HMT that fills the requirements such as durability, responsiveness, compactness, etc. for application to large motorcycles. Coupled with the electronic control system, the infinitely variable automatic transmission “Hondamatic” has been realized. As for the first practical application, Hondamatic has been applied to the ATV in the North American market, where the working conditions are severest. The research and development of HMT is still going on to make the system suitable for motorcycles.
|Key points of development|
|The “Hondamatic” consists of the
piston-type hydraulic pump driven by the engine power (torque
and revolutions) and the piston-type hydraulic motor located
in the opposite side on the same axis. It is a hydraulic mechanical,
infinitely variable transmission (HMT) using the coaxial layout,
with the output shaft taking out the power from both “the
hydraulic power transmission in that the torque from the produced
hydraulic pressure is increased in the motor side” and
“the mechanical transmission from the direct spinning
drive from the pump”. Honda applied an electronic control
system to the HMT developed over a long period of time, and
thus realized the compact, infinitely variable automatic transmission.
The “Hondamatic” features high performance under
various working conditions through the precise control of the
reduction ratio depending on the running conditions, in addition
to the inherent high transmission efficiency of HMT.
|Applied to American spec ATV subjected to use in adverse environment|
|The ATV is used mainly in North America for a
wide variety of uses, from utility purposes at farms and ranches
to recreational uses such as hunting, fishing, trail rides,
etc. Currently, more than 700,000 units are sold in a year and
the volume is still growing. In addition to durability and reliability,
Honda considered mount-ability into the engine and performance,
and decided to apply the electronically-controlled HMT system
that has been developed over a long period of time. The newly
developed transmission system, having the same level of durability
as the engine unit and the engine brake performance similar
to a gear transmission system is named as “Hondamatic”
and applied to the Honda’s 500cc class ATV “Rubicon”.