The servo pump shown in Fig. 6.27 is like that shown in Fig. 6.26, except a torque motor is used to position the spool of…
Before beginning our discussion of closed-loop hydrostatic transmissions, it is necessary to first learn how a servo-controlled pump operates. A variable displacement axial piston pump…
A configuration where all four wheels are powered is shown in Fig. 6.18. A single pump provides flow to four motors. This machine can be…
The vehicle shown in Fig. 6.17 has three wheel motors supplied by the same pump. In the design of such a vehicle, care must be…
The vehicle shown in Fig. 6.14 has a separate in-line hydrostatic transmission for each drive wheel. The engine delivers power via a universal joint driveline…
As previously mentioned, it is often necessary to provide a road speed, so the machine can be moved on the highway between job sites. (Generally,…
Wheel motors, mounted at both rear wheels (Fig. 6.12), is a variation of the configuration shown in Fig. 6.11. This arrangement eliminates the universal joint…
A hydrostatic transmission provides improved maneuverability, but at a cost. The efficiency of a hydrostatic transmission is always lower than a discrete-gear transmission. A discrete-gear…
The same vehicle shown in Fig. 6.1 is shown in Fig. 6.11 with the mechanical transmission replaced with a hydrostatic transmission; all other components remain…
A hydrostatic transmission (HST) is simply a pump and motor connected in a circuit. Other components are added to obtain certain operating features. The four…