Potential applications

Torotrak’s full-toroidal traction drive transmission technology is highly scaleable which makes the inherent benefits of the full-toroidal variator available to a wide range of industries and potential applications.

Heavy-duty construction

A key issue for heavy off-highway vehicles is controllability on variable surfaces. Torotrak’s electronically controlled, full-toroidal traction drive transmission technology with patented torque control incorporates, at no extra cost, such features as hill-hold, anti-rollback, anti-wheelspin and seamless forward-reverse shuttle to improve both accuracy and safety under the most demanding conditions. Since the functions require minimal human intervention, the driver or operator is able to concentrate more completely on the immediate task, improving productivity. Torotrak’s IVT architecture eliminates gear changing so there is no unwanted torque interruption during operation. Compared to a hydrostatic transmission of equivalent capacity, Torotrak’s technology offers product cost savings and vehicle fuel efficiency benefits.

Mining equipment

The mining industry faces many of the same problems as the heavy-duty construction market and Torotrak’s full-toroidal traction drive transmission technology is able to bring the same benefits for vehicles operating above and below ground.

At the cutting face, mining machines fitted with Torotrak’s variable speed drive technology with torque control can provide a constant, controlled high torque to the cutting head, independent of cutting speed, making it easier for machines to safely cut through difficult hard spots. The seamless speed variation inherent in the variator eliminates the compromise of fixed ratio transmissions; the ideal ratio is always available.

Marine applications

The requirements of the marine industry have many parallels with land-based applications and Torotrak’s full-toroidal traction drive transmission technology is able to offer similar benefits. Examples include:

• Maximum engine efficiency during prolonged cruising coupled with near silent operation, similar to the needs of a long distance bus
• Good controllability during low speed manoeuvres in harbour, including shifting from forward to reverse, analogous to the needs of a farm tractor or forklift truck
• Lower capital cost than comparable hydrostatic transmissions

Specific benefits of Torotrak’s full-toroidal traction drive transmission technology for marine applications include:

• Compatibility with different engines without requiring physical gearing changes; engines with differing torque curves and rev ranges can be controlled to operate at their individual optimum settings without changes to the physical specification of the variator or the engine
• Substantial fuel economy gains for planing craft by throttling back the engine and gearing up the transmission ratio once ‘on the plane’
• Efficiency benefits from the ability of the transmission to optimise the prop speed for any given boat speed (not possible with a conventional transmission)

Gensets

AC generators have to run at a fixed speed in order to generate power at the appropriate alternating current frequency. By using standard technology the engine also has to run at a fixed speed which means that the most efficient areas of the engine’s load/speed map are simply unavailable. At times of low electrical power demand, electrical energy may have to be wasted in load banks simply to maintain an acceptable engine operating condition! Interposing Torotrak’s technology between the engine and the generator allows decoupling of the engine speed from the constant generator speed. This allows a number of advantages:

• The engine always operates at the speed / load setting that will give minimum fuel consumption for the specific electrical load required. NB The transmission will respond to changes in demand more than quickly enough to maintain generator speed and thus 'clean' power
• Because the maximum engine speed can be increased, a smaller, lighter, cheaper engine can be specified for a given power requirement
• Underloading can generally be eliminated, obviating the need for load banks and wasteful operation at low load
• Problems of cylinder glazing, excessive oiling and port fouling can be virtually eliminated by using the Torotrak full-toroidal traction drive technology because they arise primarily when the engine is run under high speed, light load –an inefficient running condition avoided using this technology