Function

 
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Function

Downsizing allows machine performance to be maintained even while reducing the installed drive power. In the ideal case downsizing results getting below the “magic” 56 kW limit for the diesel engine. In downsizing, the efficiency of the hydraulics is drastically increased and the available energy used more efficiently. The chief areas for optimization are the travel drive, the working hydraulics and the electronic control.

With the downsizing system the available engine output was reduced from 68 kW to 55 kW while maintaining the same machine performance. This significantly reduced the challenges presented by the TIER 4 final emissions requirements.

 

Example of a downsizing system from Rexroth
on a compact loader

 
  Original system: compact loader with 68 kW Downsizing system: compact loader with 55 kW Efficiency increase
Optimized travel drive 350 medium pressure pump 400 bar high pressure pump A24VG, keeping MCR radial piston motors Approx. 17%
Radial piston motor Radial piston motor and A6VE variable motor combined with a GFT planetary gearbox Approx. 4%
Improved working hydraulics Open center control block Load sensig system with an A10VO pump combined with the closed center compact loader valve (SSLV) Improvement and efficiency increase in the working hydraulics
Use of electronic control No electronic control Electronic control For fully optimizing the energy flow from engine to travel drive and working hydraulics