The increased use of piston type hydrostatic drives on vehicles creates a greater need for understanding their application requirements. The hydraulic circuitry must be arranged to accommodate: braking, wheel spin out, differential speeds, and overhauling loads. Equal consideration must be given to the fluid type, filtration, temperature control, and reservoir configuration.
The fluids used in piston type drives must be kept clean, must be kept within a safe operating temperature range, and must be compatible with all of the component parts of the system. Experience at Dynex in over 15 years of applying this type of equipment, shows that 25 micron filtration provides good protection. We have found that heat exchangers are not normally required in open loop systems.
The fluids selected for a piston type hydrostatic drive should have characteristics that promote long life. The importance of proper additives should be realized and whether or not the fluid will break down under the action of the drive components. Chemical reactions that could damage seals, or cause undesirable coatings on the internal parts of the equipment, must be avoided.