Eaton Hydraulic Series 76 Manual Displacement Variable Motor Control

This type of control is them common control used on these kinds of motors. It is normally activated by direct mechanical type linkages and cables. The control is a two way position, four way closed center mechanical servo control valve.  There are some difference in the pump and motor control, the control spool is biased (has a cut into the spring washer) to full or maximum swashplate angle with no command to the control handle. It will give it a more control pressure for a full swashplate angle for maximum torque at startup.

The valve has a positive feedback linkage that is attached right on the swashplate. When it is set for minimum swashplate angle, the control spool is moved porting control pressure to the s2 servo piston, forcing the s1 servo piston assy to the bottom right next to the top of the servo sleeve.  The s1 servo piston assy controls the swashplate minimum angle. It uses shims to clamp in between the servo piston and servo piston spacer to warrant the minimum swashplate angle. The motor uses positive feedback linkage to set the swashplate at any given angle, whether maximum or minimum.

If you need more info on this, please call us at 800-361-0068

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