Loading and unloading arm with lifting device

The loading and unloading arm with the lifting device comprises a base, a force arm is arranged above the top of the base, and rectangular plates are fixedly connected to the positions, close to the left side and the right side, of the bottom of the base. Through mutual cooperation of a first servo motor, a double-groove wheel, a transmission belt, a single-groove wheel, a first threaded rod, a first threaded sleeve, a sliding plate and connecting rods, force arms fixed to the ends of the two connecting rods can move upwards through the two connecting rods fixed to the sliding plate, and material conveying can be conveniently conducted on material storage tanks with different heights; through mutual cooperation of a second servo motor, a driving bevel gear, a driven bevel gear, a second threaded rod, a second threaded sleeve, a rectangular block, a limiting rod, a connecting plate, a hinge rod, moving plates and universal wheels, the two universal wheels fixed to the adjacent moving plates can make contact wi