Hydraulic jack is based on Pascal's principle, that is, the pressure of liquid is the same everywhere, so that in the balance system, the pressure exerted on the smaller piston is relatively small, while the pressure exerted on the larger piston is relatively large, which can keep the liquid still. Therefore, through the transfer of liquid, different pressures at different ends can be obtained, thus achieving the purpose of conversion. The hydraulic jack we often see uses this principle to realize force transmission.
The mechanical jack adopts the mechanical principle, and the use method is to pull the handle back and forth, pull the claw to push the ratchet wheel to rotate, and the small bevel gear drives the large bevel gear to rotate the weight lifting screw, so that the lifting sleeve can rise or fall to achieve the effect of lifting tension. But not as simple as a hydraulic jack.