Structural Features of Four-Wheel-Drive Off-Road Forklifts

Structural characteristics of the four-wheel-drive off-road forklift are as follows: (1) Good passability with all-wheel drive for off-road use. There is no differential between the axles, and large-diameter wide-base semi-steel tires are adopted. (2) Articulated frame is used. The frame articulation angle generally reaches 30° to 40°, and the steering system is simple, requiring only an ordinary steering drive axle to achieve a small turning radius. Operating the steering wheel causes the frame to swing horizontally, facilitating alignment of the forks with the load. (3) All-wheel braking. Except for small-tonnage forklifts that use expanding shoe brake structures, most adopt caliper brakes, while large-tonnage forklifts also use wet brakes. The parking brake is mainly a handbrake. (4) The rear axle of the off-road forklift is fixed to the frame, while the front axle can swing vertically relative to the frame. Support hydraulic cylinders are installed between the frame and the front axle; when the forklift performs lifting operations, the hydraulic cylinders are operated to keep the lifting gantry in a lateral position; when the vehicle travels again, the upper and lower chambers of the hydraulic cylinders are interconnected through damping orifices, ensuring smooth vehicle travel. (5) The wheelbase and track width are relatively large, enhancing the vehicle's lateral and longitudinal stability. (6) Good mobility. The travel speed is generally 30 to 40 km/h, with good acceleration performance and a certain gradeability. (7) Driver seat arrangement. This provides the operator with better visibility during loading, and the driver's seat is generally positioned at the front. (8) Travel system. Similar to loaders, there are various mechanical transmission options, such as hydraulic shift mechanical transmission, hydraulic transmission, and hydrostatic transmission. The difference lies in the use of full power matching, where the load condition is full-load climbing operation.