Farm Ireland
Independent.ie

Tuesday 25 July 2017

SDF broadens use of 'vario' transmissions

Bruce Lett

SAME Deutz-Fahr (SDF) have now extended the use of vario transmissions in their range of tractors with the introduction of two new TTV models to the Agrofarm range.

New are the Deutz-Fahr Agrofarm TTV 420 and Agrofarm TTV 430, rated at 100hp and 110hp respectively from their four-cylinder engine.

The new Agrofarm TTV models are based on the recently introduced Profiline 420 and 430 versions and these new models offer stepless speed adjustment from 0.1-40kph in two working ranges.

Designed and built in-house, the T5100 vario transmission is of a compact design for use specifically in low to medium horsepower tractors. Combining mechanical and hydrostatic elements, the transmission comprises a two-stage planetary transmission with power-shuttle and two-speed power-shift, plus a hydrostatic pump and motor.

The mechanical aspects of the transmission provide the two working ranges and the hydrostatic element the infinitely variable speed adjustment -- up to 23kph for heavy draft work in the first range and up to 40kph for lighter duties and road transport in the second range.

According to SDF, the transmission achieves almost 100pc mechanical efficiency from 5-18kph in the first range and 10-38kph in the latter.

The manufacturers claim the TTV gearbox allows the Agrofarm models to run with a reduced engine speed of 1,800rpm at 40kph, keeping below the engine's 2,100rpm maximum speed and giving the potential for improved fuel economy.

Not short on abilities, SDF's little TTV versions offer a cruise control function plus the TTV's operating characteristics can be adjusted using a dial from Eco through to Power settings.


The Eco mode setting makes full use of the TCD2012 engine's 1,400-1,700rpm constant torque band, while Power mode operates in the 1,800-2,100rpm constant power zone.

In pto mode, engine speed and load can be managed in relation to forward speed. Both models are equipped with what SDF call a 'Sense Clutch', which allows forward/reverse shuttle sensitivity to be adjusted through five settings to suit the operator or task being carried out.

The new Agrofarm TTV models are based on the recently introduced Profiline 420 and 430 versions, which feature a four-pillar cab instead of the traditional six. This is in keeping with many other manufacturers, and on the SDF tractors it provides 60mm extra head room over the standard model.

A console on the right-hand side allows the transmission and pto functions to be selected, while a display on the cab's right-hand A-post displays the selections made.

The Agrofarm TTV specification also includes four electronically controlled spool valves, electronic joystick and rear linkage. Lift capacity is a respectable 6,200kg.

Irish Independent