Axial Piston Variable Pump A7VO - Group VH A/S

Blocked for new applications / Für Neuanwendung gesperrtRE 92 202/03.06 A7VO Bosch Rexroth AG 3/32Technical DataHydraulic fluidBefore starting project planning, please refer to our datasheets RE 90220 (mineral fluid), RE 90221 (environmentallyacceptable press ure fluids) and RE 90223 (HF pressurefluids) for detailed information regarding the choice of pressurefluids and conditions of use.The A7VO variable pump is not suitable for use with HFA. IfHFB, HFC and HFD or environmentally acceptable pressurefluids are being used, the limitations regarding technical dataand seals mentioned in RE 90221 and RE 90223 must beobserved.When ordering please indicate the used hydraulic fluid.Viscosity rangeWe recommend that a viscosity (at operating temperature) foroptimum efficiency and service life purposes ofν opt = optimum viscosity 16...36 mm 2 /sbe chosen, taken the tank temperature (open circuits) intoaccount.Limits of viscosity rangeThe following values apply in extreme cases:ν min = 5 mm 2 /sshort term (t < 3 min) at max. permitted temperaturet max = +115°C.ν max = 1600mm 2 /s,short term (t < 3 min) with cold start (p < 30 bar, n ≤ 1000 rpm,t min = -40°C).Note that the maximum hydraulic fluid temperature of 115°Cmust not be exceeded locally either (e.g. bearing area). Thetemperature in the bearing area is - depending on pressureand speed-up to 12 K higher than the average leakage fluidtemperature.Special measures are necessary at temperatures between-40°C and -25°C. Please contact us.See RE 90300-03-B for detailed information about use at lowtemperatures.Selection diagram-40° -20°16001000600400vis co si ty ν in mm 2 /s200100604020100° 20° 40° 60° 80° 100°160055-40° -25° -10° 0° 10° 30° 50° 70° 90° 115°tem pe ra ture t in °Ct min = -40°CVG 22VG 32VG 46VG 68VG 100hydraulic fluid temperature range3616t max = +115°CDetails regarding the choice of hydraulic fluidThe correct selection of hydraulic fluid requires knowledge ofthe operating temperature in relation to the ambient temperature,in an open circuit the tank temperature.The hydraulic fluid should be selected so that within theoperating temperature range, the operating viscosity lies withinthe optimum range (ν opt ) (see shaded section of the selectiondiagram). We recommend that the highest possible viscosityrange should be chosen in each case.Example: At an ambient temperature of X° C an operating temperatureof 60° C is set in the circuit. In the optimum viscosityrange (ν opt ; shaded area) this corresponds to the viscosityclasses VG 46 or VG 68; to be selected: VG 68.Please note: The leakage fluid temperature, which is affectedby pressure and rotational speed, is always higher than thetank temperature. At no point in the system may the temperaturebe higher than 115°C.If this cannot be achieved due to unusual operating parametersor high ambient temperatures, we recommend to apply bearingflushing at port U.FiltrationThe finer the filtration, the cleaner the fluid and the longertheservice life of the axial piston unit.To ensure proper function of the axial piston unit, the hydraulicfluid must have a cleanliness level of at least20/18/15 according to ISO 4406.At very high hydraulic fluid temperatures (90°C to max. 115°C),a cleanliness level of at least19/17/14 according to ISO 4406 is required.Please contact us if these cleanliness leveles cannot be achieved.