Hydraulically driven, multiple rotor riding trowel

摘要

High performance, multiple rotor riding trowels for finishing concrete comprise hydraulic circuitry enabling complete joystick control to the operator. The rigid trowel frame mounts separate spaced-apart, downwardly-projecting, bladed rotor assemblies that frictionally engage the concrete surface. The rotor assembly blades finish the surface while supporting the trowel. The rotor assemblies are tilted with double acting, hydraulic cylinders to effectuate steering and control. Double acting hydraulic cylinders also control blade pitch. Separate gimbaled, hydraulic motors revolve each rotor assembly. A joystick system enables operator hand control with minimal physical exertion. The joystick system activates electrical circuitry that fires solenoid control valves to energize various hydraulic cylinders that tilt the rotors and alter blade pitch. The hydraulic steering control circuit driven by a motor driven pump pressures a flow divider circuit to control the solenoid tilt control valves. A bypass-valve in line before the flow divider enables an operator to customize the trowel steering speed. A motor drive control circuit responsive to a hydraulic pump controls each hydraulic drive motor, and provides for speed control and heat dissipation.