In introducing an axial piston variable pump for hydraulic systems in the new size 18, Bosch Rexroth has narrowed the price gap to identically-sized gear pumps. Manufacturers of mobile equipment in the agricultural and construction sectors can now implement the efficiency-enhancing technology on tractors and vehicles of 37 kW and higher, and auxiliary drives on larger vehicles.

In enabling demand-controlled power generation for lower-power range agricultural and construction mobile equipment, manufacturers and operators can improve machine efficiency by up to 16 percent, while simultaneously lowering exhaust emissions.

With the use of variable pumps previously restricted to machines in the upper power ranges, lower-powered machines were designed with energy-intensive open-centre systems using fixed pumps. The A1VO offers a range of available control types – pressure control, load-sensing control and electronic control – providing an economically-attractive alternative for many hydraulic systems that previously used fixed pumps.  

Breakthrough technology for mobile equipment
Hydraulic systems with demand-controlled power generation supplied by variable pumps are central to a more economical mechanical operation. The A1VO is fitted with an integrated load-sensing controller to assume demand-controlled power generation, increasing the efficiency of implement hydraulics and improving the responsiveness of load handling.  

Comprehensive simulations using OEM engine map data of a commercially-available 66 kW diesel motor demonstrated that the A1VO reduces energy savings by between 10 and 16 percent. On a projected tractor life of 6 000 hours and assuming a typical load cycle distribution, the unit was calculated to produce savings of around 10 000 litres of diesel. The variable pump achieves the greatest fuel savings in partial-load operations, such as holding the plough during transportation or working with the front loader.

The A1VO pump comes in two sizes, 18 and 35 cm3, both of which are housed in a compact, flexible and reliable enclosure that allows a simple installation into existing hydraulic circuits without altering the underlying specifications. The A1VO can be easily combined with other pumps through a universal through-drive and interchangeable adapter. By using a seven piston rotary group, and by integrating all ports and the controller into the port plate, increased leak tightness is achieved in a compact, robust enclosure.

The A1VO is also designed for applications such as auxiliary drives in large vehicles. It can easily function as a supply unit for hydrostatic fan drives. For this reason, Bosch Rexroth has supplemented the controller portfolio of the A1VO to include a cartridge-style electro-hydraulic controller.

As the official partner to Bosch Rexroth across sub-Saharan Africa, the Bosch Rexroth A1VO variable pump is distributed through Hytec, a Hytec Group company.