The lifting unit comprises a cylinder, a linear guide rail, a rack, a gear shaft
assembly and a self-lubricating
assembly, a lifting mode that a gear is matched with the rack is adopted, lifting space cannot be occupied in the lifting direction, low-position lifting movement and high-position lifting movement can be achieved, and the self-lubricating
assembly is arranged, so that the lifting roller
bed is convenient to lift. Lubricating
oil can be provided at the meshing position of a rack and a gear and on a sliding block of a linear guide rail, it is guaranteed that wheel clamping is avoided during meshing operation of the rack and the gear, overheating caused by too large
friction force can be prevented, meanwhile, sliding smoothness of the sliding block on the linear guide rail is guaranteed, and stable operation of the whole lifting unit is guaranteed. The lifting roller
bed comprises the lifting unit, a roller
bed table board unit, a roller unit, a roller driving unit, a lifting driving unit, a stopper unit and a positioning pin unit, the lifting roller bed can achieve lifting movement and horizontal conveying of the sleigh, and different production requirements can be met by adopting standardized and modularized design.