Screw Jack

                                           Screw Jack

What is a screw jack? How can it work? Which guideline of material science does it use? How to figure exertion required and productivity of a screw jack? 

The standard, on which a screw jack works is like that of a slanted plane. On the off chance that one complete turn of a screw string is envisioned to be loosened up, from the body of the screw jack and created, it will frame a slanted plane, as appeared in Fig. 1.22. 

From the geometry of the figure, 

Screw Jack 

In a screw jack, the exertion (P) required at the circuit of the screw is the same as examined for the slanted plane, for example 

For raising the heap, P = W tan (α + ϕ) 

furthermore, for bringing down the heap, P = W tan (α - ϕ) 

Notes: 

1. At the point when the grating is ignored, at that point ϕ = 0. All things considered 

2. The productivity of a screw jack is given by 

The proficiency of a screw jack 

3. The proficiency of a screw jack is most extreme, when helix edge, 

Greatest productivity of a screw jack 

furthermore, the most extreme effectiveness is given by 

Greatest productivity of a screw jack