A PROPOSAL ON THE PROJECT TOPIC:
DESIGN AND FABRICATION OF MOTORIZED SCREW JACK FOR A FOUR WHEELER
BY
OKARDI RAYMOND BELEMA U08ME1011
INTRODUCTION
Screw jack
A jackscrew is a type of jack which is operated by turning a lead screw. It is also known as a screw jack, and is commonly used as car-jacks.
A jackscrew's compressive force is obtained through the tension force applied by its lead screw. An Acme thread is most often used, as this thread is very strong and can resist the large loads imposed on most jackscrews while not being dramatically weakened by wear over many rotations. These types are self-locking, which makes them intrinsically safer than other jack technologies like hydraulic actuators which require continual pressure to remain in a locked position. Most jackscrews are lubricated with grease.
Advanced screw mechanisms may use a recalculating-ball nut to minimize friction and prolong the life of the screw threads, but such jackscrews are usually not self-locking. The thread profile of such screws is semicircular, not trapezoidal as in an Acme thread.
Motorized Screw Jack has been conceived having studied the difficulty in lifting the any type of light vehicles. Our survey in the regard in several automobile garages, revealed the facts that mostly some difficult methods were adopted in lifting the vehicles for reconditioning. Now the project has mainly concentrated on this difficulty, and hence a suitable device has been designed. Such that the vehicle can be lifted from the floor land without application of any impact force. The fabrication part of it has been considered with almost case for its simplicity and economy, such that this can be accommodated as one of the essential tools on automobile garages.
This device the motorized screw jack for automobile garages has been developed to later the needs of small and medium automobile garages, who are normally man powered with very minimum of skilled labours. In most of the garages the vehicles are lifted by using hand operated screw jack. This needs high man power and skilled labours. In order to avoid all such disadvantages. This, motorized screw jack has been designed in such a way that it can be used to lift the vehicle very smoothly without any impact force. The operation is made be simple that even an unskilled labour can handle, by just demonstrating the working of the motorized screw jack once.
ABSTRACT
Motorized/Automatic Screw Jack: Fabrication of a motorized screw jack is easy especially when the parts are available in the market. This mechanical engineering project can be easily completed by integrating an electric motor with a screw jack.
A screw jack or a Jackscrew is operated by turning a lead screw. The height of the jack is adjusted by turning the lead screw. This can be done either manually or by integrating an electric motor with it. This integration is our project.
The difficult part in the project may be finding a low speed motor that is able to work at 12V. This is because the battery output of an automobile is 12V, and the electricity needed for the operation of the screw jack is taken from this battery.
Another will be regarding speed reduction. 12V motors usually operate at higher speeds, likely at 4000 or 5300 rpm. So reducing this high rpm to the required lower rpm for the operation of screw jack without bulky accessories or power loss is quite challenging. But still this is one of the interesting projects in mechanical engineering.
A screw jack includes a pair of frames disposed between a pair of walls, a bracket disposed above the beams, and a bolt engaged between the lower ends of the frames. An actuating device is engaged with the bolt and includes a motor for rotating the bolt so as to move the lower ends of the frames toward each other or away from each other and so as to elevate the bracket. The bracket can be easily move up and down by the motorized actuating device. The present project relates to a jack, and more particularly to a motorized screw jack assembly. Typical screw jacks comprise a handle for driving a bolt element so as to elevate an object. However, it will be difficult for most women to operate the handle. In addition, the elevation speed of the screw jack is slow. The present project has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional screw jacks. The primary objective of the present project is to provide a screw jack which is motorized such that the screw jack can be easily operated. In accordance with one aspect of the project, there is provided a jack assembly comprising a pair of wall members fixed together in parallel with each other and each including two horizontal grooves and a vertical groove arranged between the horizontal grooves; a pair of frames including a middle portion pivotally coupled together at a shaft, the shaft including two ends slid ably engaged in the vertical grooves of the wall members, the pair of frames including two lower ends and two upper ends, two blocks pivotally secured to the lower ends of the pair of beams at two axles, the first axles including end portions slid ably engaged in the horizontal grooves; a bolt engaged through the blocks; a bracket; a pair of arms including lower ends pivotally coupled to the upper ends of the frames and upper ends pivotally coupled to the bracket; and means for
actuating the bolt so as to move the blocks toward each other or away from each other in order to move the bracket upward or downward. Accordingly, the motorized screw jack in accordance with the present project can be easily operated with the motorized actuating mechanism. Although this project has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted.
SPECIFICATION
Features Structure : Electric Motor Voltage : D.C 12V~14V Current : 15 Amp
Operating Method : Vertical Lift Screw Operating Type Operating Range : Max. 346mm (13.62") Minimum Height : 141mm (5.59") Vehicle Weight : Within 2,500kg (5,510 lbs) Power : DC 12v Car Cigar Lighter or Car Battery Operating Time: Around 1 Min 30 Sec Special Features : High-Powered Motor Simple and compact Design Easy one button operation
WORKING PRINCIPLE
The lead-acid battery is used to drive the d.c motor. The d.c motor shaft is connected to the spur gear. If power is given to the D.c motor, it will run so that the spur gear also runs to slow down
the speed of the D.C motor. The screw jack moves the screw upward, so that the vehicle lifts from ground. The vehicle is lifted by using the lifting platform at the top of the screw jack. The motor draws power supply from the battery. The lifting and uplifting is done by changing the battery supply to the motor. ADVANTAGES
1. The loaded light vehicles can be easily lifted. 2. Checking and cleaning are easy, because the main parts are screwed. 3. Handling is easy. 4. No Manual power required. 5. Easy to Repair. 6. Replacement of parts are easy 7. The moving parts of this system are cooled by the oil itself used. Thus this project does not require any cooling arrangements. DISADVANTAGES
1. Cost of the equipment is high when compared to ordinary hand jack. 2. Care must be taken for the handling the equipment such as proper wiring connection, battery charging checkup, etc. APPLICATIONS
1. It is useful in auto-garages. 2. In emergency conditions like tyre flat out. 3. This motorized screw jack is used for lifting the vehicles. 4. Thus it can be useful for the following types of vehicles in future;
Maruti, Ambassador, Fiat, Mahindra, TATA CONCLUSION
Screw Jacks are the ideal product to push, pull, lift, lower and position loads of anything from a couple of kilograms to hundreds of tonnes. The need has long existed for an improved portable jack for automotive vehicles. It is highly desirable that a jack become available that can be operated alternatively from inside the vehicle or from a location of safety off the road on which the vehicle is located. Such a jack should desirably be light enough and be compact enough so that it can be stored in an automobile trunk, can be lifted up and carried by most adults to its position of use, and yet be capable of lifting a wheel of a 4,000-5,000 pound vehicle off the ground. Further, it should be stable and easily controllable by a switch so that jacking can be done from a position of safety. It should be easily movable either to a position underneath the axle of the vehicle or some other reinforced support surface designed to be engaged by a jack. Thus, the product has been developed considering all the above requirements. This particular design of the motorized screw jack will prove to be beneficial in lifting and lowering of loads.
