Bevel gear operated Screw Jack for Lifting Operation


With the increasing level of technology, researchers all over the world are working continuously to improve and implement better and robust design of materials at workplace for productivity, efficiency and effectiveness. Detailed design procedure of a quick lifting screw jack is
presented in this paper. The design is fundamentally a modification of the conventional scissor jack.
The problems associated with the conventional jacks are the ergonomic snags experienced by operators due to prolonged bending or squatting positions during operation. These problems of waist pain and backaches are as a result of continuous turning of the wrench or crank shaft in an uncomfortable position for a long period. These led to the design and modification of quick lifting screw jack with gear arrangements that are safe, reliable and capable of raising or lowering heavy load with little effort. The results showed that the introduction of the crank and gear mechanism would help reduce difficulty in operation, reduce time, increase efficiency and effectively control the difficulties concomitant with Ergonomics – which is an ultimate sensitivity in design process.

bevel gear operated screw jack
bevel gear operated screw jackf

Over the years, engineers, scientist and ergonomist have extolled the conventional automobile screw jack (scissors jack) as being very efficient, yet continue to seek new designs to increase reliability and reduce its shortcomings and maintenance costs. Screw application is used in the elevation of vehicles or objects. The operation of the screw jack is such that it comprises a handle for driving a bolt element (Lead Screw) manually to adjust the height of the jack to elevate a vehicle or an object. Existing jacks are of great disadvantage to elderly women especially under unfavorable weather condition . A mechanical jack is a device which lifts weighty or heavy equipment and vehicles so that maintenance can be carried out underneath at workplace or manufacturing setting . A jack screw is a type of jack which functions by turning a lead screw. It is commonly used to lift heavy load to a height. A good example is the car-jacks. In the case of a screw jack, a small force applied in the horizontal plane is used to raise or lower large load . A good number of operational staff in manufacturing, bottling, oil and gas and other multi-national companies perform task in a squatting or cowering position for a long period. These results to inefficiency at workplace due to ergonomically imbalance position they encounter which often times give rise to back ache and poor body architecture in the future.

These present available jacks further require the operator to remain in prolonged bent or squatting position to operate the jack. Due to its difficulties, body pains, back ache and others can emerge as a result of continuous turning of the wrench or crank shaft in an uncomfortable position for a long period. The statement of problem has led to the motivation of designing a modified quick lifting screw jack with gear arrangement. The introduction of the bevel gear will help reduce difficulty in operation with a handle incorporated in the design and also reduce time spent to a very minimum.

Material Selection of Parts:
The choice of material is very important in the design of an automobile jack as in the case of other engineering designs. It is one of the most important decisions a designer is called to make.
The decision is usually made before the dimensions of the part are established. One very important factor in material selection is the strength. Other factors include wear, corrosion, weight, noise, lubrication, marketability, manufacturability, safety, functionality, cost, etc. Some aforementioned have to do unswervingly with the dimensions, the material, the processing, and the joining of the element of the system. For effective performance of jack, mild steel is majorly used because of its strength, toughness and low cost. It provides material properties that are acceptable for the application. Finally, the selected material of mild steel gives a reduced weight of the jack.

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