Scania: Freewheeling retarder reduces fuel consumption

[kscarbel]

Wall Street Journal / May 14, 2014

Many trucks have some form of auxiliary brakes. For almost two decades Scania's customers have been able to appreciate just how powerful, yet smooth, effect a hydraulic retarder from Scania can provide. Besides comfort and a relaxing drive, it also provides savings by reducing the need for normal brake system maintenance. In this latest version, the retarder automatically disengages and freewheels when not in use to save on fuel. And it is now even more powerful than before.

One of the Scania Retarder models is now available in a new version (R4100D) that automatically disengages and enters a freewheeling mode when not active. This reduces drag losses because both vaned wheels that provide braking power when rotating in oil are disengaged. Actual fuel savings will vary depending on road conditions, but an average of a half percent reduction is taken as the rule of thumb.

The driver doesn't have to do anything. When braking power is needed, the freeSHYwheeling stops and the engagement takes place smoothly and immediately using a type of synchronisation that is similar to that in Scania gearboxes. Besides not requiring any energy, the freewheeling retarder also provides higher braking power, 4,100 Nm instead of 3,500 Nm, as well as an increased braking effect at lower engine rpm with the help of higher gear ratios.

"Reducing fuel consumption is Scania's main priority," says Örjan Åslund, responsible for Product Affairs at Scania Trucks. "The freewheeling retarder produces further savings that also contributes to an elevated driving experience."

"The activation of the retarder itself is either initiated by the driver -- via a lever on the steering column or with a light touch of the brake pedal -- or when the cruise control requests braking, says Åslund. As soon as the retarder is not in use, it freewheels again on its own. But it remains ready to smoothly and firmly change from freeSHYwheeling to full braking power in no time."

Deliveries of the new retarder to customers will begin in the first quarter of 2015.

Scania is one of the world's leading manufacturers of trucks and buses for heavy transport applications, and of industrial and marine engines. Employing some 41,000 people, the company operates in about 100 countries.

[mack mhe9]

Sounds like a Cat brake saver? Drove a Cat 3406a with one, thought it was a nice set up at the time.

[kscarbel2]

Scania Retarder interacts with the cruise control, exhaust brake and wheel brakes to provide total speed control at the touch of a button or a dab on the brake pedal.

Completely integrated with the cruise control, as well as with the service brakes and exhaust brake when cruising, a vehicle with the Scania Retarder provides automatic speed control up and down the hills.

Retarder braking is either initiated with a dab on the brake pedal or controlled manually with the lever on the steering column.The gap between cruising speed and downhill speed can be set in small steps using a button on the steering wheel.

When set to work automatically with the exhaust brake and the service brakes, service brake applications are reduced by up to 75 percent and brake wear minimised.

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[scania v8]

Functioning superb... and indeed saves a lot of brake overhaul (see picture breakpad wear indicator) was after little less then 1000000km 

[mrsmackpaul]

Thats pretty impressive