Four-set linkage screw jack system can be I and T configuration, transmission efficiency can be 85% . It usually consists bevel gearbox, screw jack, electric motor, gear reducer, hand wheel, pillow block bearing, jaw coupling, line shafting. The screw jack system is widely used in wood working machines, plastics processing machines, textile machines, assembly equipment in the automobile and aircraft industries, food and beverage production equipment as well as packaging machines.