CONTINUOUSLY VARIABLE HYDROSTATIC TRANSMISSION HAVING RATIO CONTROLLER ACTUATING COMPONENTS INCORPORATED IN OUTPUT SHAFT

摘要

To control the transmission ratio of a continuously variable hydrostatic transmission including an input shaft (14), an output shaft (16), a pump unit (18) driven by the input shaft (14), a grounded motor unit (20), and a wedge-shaped swashplate (22) drivingly and pivotally connected to the output shaft (16) in hydraulic fluid-communicating position between the pump and motor units (18, 20), a ratio controller is provided having a hydraulically actuated piston (128) incorporated internally of the output shaft (16). A pilot valve (150), also incorporated internally of the output shaft (16), operates to create differential fluid pressures at opposite end faces of the piston (128), forcing axial motion of the piston and ratio-changing pivotal movement of the swashplate (22) linked to the piston.