Honda Introduces New Infinitely Variable Transmission for Motorcycles

Green Car Congress ^ | 10-4-07

[martin_fierro]

Honda Introduces New Infinitely Variable Transmission for Motorcycles

4 October 2007

Hft

The Human-Friendly Transmission.

Honda Motor Co. has developed the Human-Friendly Transmission (HFT), a new automatic transmission system for motorcycles using Honda’s own infinitely variable hydraulic mechanical transmission (IVT). The HFT will be installed on the DN-01, a new motorcycle that is scheduled for market launch at the 40th Tokyo Motor Show.

The HFT is a compact and efficient IVT system encompassing functions for starting, power transmission and shifting, all on a single shaft. The basic configuration of the system consists of an oil pump for converting engine power into hydraulic pressure, and an oil motor for converting the hydraulic pressure back into power for output. Hft2 Configuration of the HFT. Click to enlarge.

Both are made up of multiple pistons, a distributor valve and a swash plate for piston operation, while the cylinders are integrated into the output shaft, forming the characteristic structure of the HFT.

The HFT offers a selection from two fully automatic shifting modes: D mode for ordinary riding and S mode for a sporty riding experience; or a 6-speed manual mode, which gives riders the option of riding with a manual transmission feel.

The HFT also features the world’s first lockup mechanism for an infinitely variable hydraulic mechanical transmission, according to Honda. When cruising, this lockup mechanism works to minimize transmission efficiency losses, contributing to improved fuel economy.

In 1980, Honda introduced the Tact, a machine equipped with a Honda continuously variable transmission, the V-Matic. Honda has continued to develop a variety of new mechanisms up into the present.

[blackie]

Ever the politician. >;-}

[tacticalogic]

Gas engine golf carts use the Milner Transmission. Extremely simple design and works!

Wonder how it would work on a tractor pto.

[JoeSixPack1]

Not sure. The concave pulleys move together and apart as the torque requirement changes pushing the belt to a larger or smaller drive diameter on the pulley thus changing the drive ratio.

Usually a pto has 3 modes, engaged or disengaged and hummin’ along. :-)

[tacticalogic]

Usually a pto has 3 modes, engaged or disengaged and hummin’ along. :-)

Which is fine as long as you want to do it at 540 rpm. :)

[eraser2005]

The pulley contraption is generally called a CVT, for Continuously Variable Transmission.

Several vehicles use this sort of transmission, including, but not limited to:

Ford Five Hundred
Ford Freestyle
Ford Escape Hybrid
Ford Focus C-MAX
Mercury Montego
Mercury Mariner Hybrid
Toyota Prius
Toyota Camry Hybrid
Toyota Highlander Hybrid
Nissan Altima
Nissan Maxima
Nissan Murano
Nissan Sentra
Honda Civic
Honda Insight

This motorcycle system is fluid-based, rather than belt, but the term Infinitely Variable is a bit of a misnomer. There are upper and lower bounds on the transmission ratio, just like a belt-driven one.... just different bounds....

[org.whodat]

Thanks, I knew it was several, but I had no Ideal it was that many, I remember the commercial last year where the were showing the woman put on lipstick and saying no shift shock. I never bothered to look up the trans but I knew it had to be a CVT trans. Built one are two racing automatics, myself. Read a good deal about how they worked back when I had a power mechanics course. LOL