Improved pumps

A new Direct Displacement Control (DDC) pump is designed to offer many advantages over previous types. Benefits include reduced installation time, longer overall machine life, extra flexibility to the vehicle design process, and lower noise.

A key feature of the Sauer-Danfoss DDC is its built-in Neutral Return Mechanism (NRM). All DDC pumps need this but, on most competing products, the complex, external unit containing linkages and springs is placed outside the pump.

On the Sauer-Danfoss pump the NRM is inside. This means installation effort is minimised, as is the number of external linkages and springs. Space is also saved, which leaves room for other components on the application Another im p ortant benefit is longer machine life. Locating the return mechanism inside the pump means it is protected and always lubricated. Users can expect more consistent machine operation and longer service intervals. Branko Horvat, product portfolio manager at Sauer-Danfoss USA, explains, “All DDC pumps need a Neutral Return Mechanism to bring the swash plate back to neutral. Historically, though, the pumps have featured external mechanisms subject to contaminants that include everything from dust and dirt to sticks and stones. In such designs, external wear points, friction, and machine vibration also add to maintenance needs and, over time, NRM performance may degrade. Placing the Neutral Return Mechanism inside the product, we have eliminated this problem. Our testing shows that the pump s r eturn p erformance c ontinues to sta y within extremely tight tolerances. The result i s lon g er service intervals and longer machine life benefiting vehicle manufacturers and end-users alike.”Flexibility is another i m p ortant feature.

The new pump is “the industr y 'sy DDC solution offering three displacements in one housing – 25 CC, 30 CC, and 35 CC.”It means that the pump installation process is the same for different vehicle models, which allows engineers to spend more time on other design issues.

The pump is designed for closed-loop operations on machines where high noise levels can be an issue. “Both the sound level and the sound quality have been improved. In fact, the DDC pump is up to 4 dB quieter than similar products available on the market and the nature of the sound or the sound quality is better too,”Branko Horvat explained.

For more information see: www.sauer-danfoss.com