SWL series screw lift jack stroke and lifting load parameter system
The stroke does not affect the rated load: The rated lifting load (such as 10t) of the SWL series is a static design value and does not automatically decrease due to stroke growth.
Long travel requires structural compensation:
Travel>500mm: It is recommended to install a middle support or guide sleeve to prevent the screw from bending and instability (Euler critical load verification);
Travel>800mm: Double screw symmetrical installation or nut movement structure must be used (load is evenly shared by the nut, resulting in better rigidity);
Travel>1000mm: It is recommended to use the ball screw version (SWLB) to reduce friction, improve efficiency and lifespan.
According to the stroke of the screw and the lifting load, refer to Figures 1-3 to find the required model of the elevator. Then, check the lifting force and speed table to verify whether the lifting speed meets the requirements. If the lifting speed found does not meet the requirements, it is recommended to choose a larger model of elevator.
Example: Given that the lifting force is F=20kN, the screw stroke is 400mm, and the lifting speed is V=0.65m/min, try to find the required elevator.
According to F=20kN and screw stroke=400mm, refer to Figure 1 and select SWL5 elevator. Check the lifting force and speed table again to verify that the SWL5 lift only allows a speed of 0.526m/min under a load of 20KN, only for heavy-duty and large elevators. Further checking the lifting force and lifting speed table, it was found that SWL10 is allowed to lift at a speed of 1.44m/min under a load of 20KN, which meets the requirements.