| 摘要 |
Steering system for an endless track type tractor having an engine, a power distribution device for equally distributing the power of the engine to two outputs, a pair of power trains each including a torque converter, a transmission and a steering brake for transmitting the power to each of a pair of lateral shafts adapted to selectively drive an endless track through a sprocket for turning the tractor rightwardly or leftwardly. The transmissions and the steering brakes are hydraulically actuated through hydraulic cylinders and electromagnetic valves controlled by a manually operable steering switch mechanism so as to shift either one of the transmissions to neutral while the related one of the steering brakes is actuated to braking position for the turning of the tractor at a rate determined by the fluid pressure supplied to the hydraulic cylinders. The steering system includes a pair of adjustable treadle pressure reducing valves each connected to the respective hydraulic cylinder for the steering brake and a treadle reducing valve coupled switch mechanism connected in parallel to the respective one of the electromagnetic valves for the steering brakes, thereby permitting the tractor to be turned rightwardly or leftwardly at a selected rate as determined by the degree of actuation of the selected one of the treadle valves. |
