Excavator Pumps Uchida Rexroth A7VO series A7VO28,A7VO55, A7VO80, A7VO107, A7VO160, A7VO250, A7VO355, A7VO500 
control for the LR, LRD, LRDH, DR, GRG, DRS, DH, EP, EPG, etc,    
Features:
Variable pump with axial tapered piston rotary group of bent-axis design, for hydrostatic drives in open circuits
For use in mobile and stationary application areas
The flow is proportional to the drive speed and to the displacement, and is infinitely variable from qv max to qv min = 0 
Wide selection of control devices
Compact, robust bearing system with long service life.
Details regarding the choice of hydraulic fluid    
The correct choice of hydraulic fluid requires knowledge of the operating temperature in relation to the ambient temperature: in a closed circuit the circuit temperature. The hydraulic fluid should be chosen so that the operating viscosity in the operating temperature range is within the optimum range (νopt) - the shaded area of the selection diagram. We recommended that the higher viscosity class be selected in each case. Example: At an ambient temperature of X °C an operating temperature of 60 °C is set. In the optimum operating viscosity range (νopt; shaded area) this corresponds to the viscosity classes VG 46 or VG 68; to be selected: VG 68. Please note: The case drain temperature, which is affected by pressure and speed, is always higher than the circuit temperature. At no point in the system may the temperature be higher than 115 °C. If the above conditions cannot be maintained due to extreme operating parameters, please consult us.