#4
Post
by Gothard » 26 May 2005, 05:24
It was steered through a double differential combined with the Naeder (a hydrostatic unit). The driver used the Naeder steering system to line up the gun as it couldn't move left or right. It ran on a Holt suspension which was covered by skirting. The suspension was leaf and coil springs on vertical articulations. The tracks were driven by the rear sprocket and could be adjusted from the inside. Had APX1 turret.
What is a hydrostatic transmission?
A hydrostatic transmission consists of a variable-displacement pump and a fixed or variable displacement motor, operating together in a closed circuit. In a closed circuit, fluid from the motor outlet flows directly to the pump inlet, without returning to the tank.
As well as being variable, the output of the transmission pump can be reversed, so that both the direction and speed of motor rotation are controlled from within the pump. This eliminates the need for directional and flow (speed) control valves in the circuit.
Because the pump and motor leak internally, which allows fluid to escape from the loop and drain back to the tank, a fixed-displacement pump called a charge pump is used to ensure that the loop remains full of fluid during normal operation. The charge pump is normally installed on the back of the transmission pump and has an output of at least 20% of the transmission pump's output.
In practice, the charge pump not only keeps the loop full of fluid, it pressurizes the loop to between 110 and 360 PSI, depending on the transmission manufacturer. A simple charge pressure circuit comprises the charge pump, a relief valve and two check valves, through which the charge pump can replenish the transmission loop. Once the loop is charged to the pressure setting of the relief valve, the flow from the charge pump passes over the relief valve, through the case of the pump or motor or both, and back to tank.
