The screw jack, also referred to as the mechanical jack, is driven by a manpower through a screw pair, and a screw or nut sleeve is utilized as a jacking member. The ordinary screw jack supports the fat by the thread self-locking function, and the structure is simple, but the transmission performance is normally low and the greenhouse gearbox return stroke is sluggish. The thread of the self-propelled screw jack has no self-locking action and is equipped with a brake. When the brake can be released, the weight can be quickly lowered by itself and the return period can be shortened, but the framework of the jack is usually complicated. The screw jack can support heavy objects for a long period, and the maximum lifting capacity has already reached 100 tons, which is widely used. Following the horizontal screw is certainly mounted on the lower part, the weight could be traversed at a small distance.

Principle useful:

The mechanical jack is among the types of manual lifting tools. Its compact structure makes reasonable utilization of the rocking of the rocker to rotate the pinion. It really is operated by a pair of conical gears to operate a vehicle the screw to rotate and push the lifting sleeve to ensure that the excess weight rises or decline.


1. Before use, it’s important to check whether the jack is regular, whether the components are flexible, add lubricating oil, and correctly estimate the weight of the large object. Make use of a jack of suitable tonnage and steer clear of overloading.

2. Adjust the technique of supporting the teeth on the rocker. First of all, turn the rocker straight in the clockwise direction by hand to make the lifting sleeve quickly ascend the top weight.

3. Insert the handle in to the rocker hole, move the deal with along, and the pounds will rise. When the red warning line shows up on the lifting sleeve, the handle should be stopped immediately. If you want to lower one’s teeth in the opposite direction, the pounds will begin to fall.


1. Always keep the top of machine clean, examine the internal structure frequently, make the pinion in the rocker flexible and reliable, and lift the lifting sleeve openly.

2. The friction surface between the lifting sleeve and the housing must be oiled anytime. Other oil filling holes ought to be lubricated regularly.

3. In order to consider the protection in use, avoid overloading, use illness, it isn’t appropriate to make use of multiple units to avoid danger.