16-01-2013, 01:06 PM
DESIGN AND FABRICATION MOTORIZED DRIVEN SCREW JACK
DESIGN AND FABRICATION MOTORIZED DRIVEN.ppt (Size: 1.76 MB / Downloads: 90)
ABSTRACT
Fabrication of motorized driven screw jack is an approach in running the screw jack by using a motor.
Where the load is lifted using Tommy bar. When the bar is rotated, the force applied on bar is used to lift the load.
Based on this principle the electrically drive screw jack is working. The comfort of lifting the jack is increased by providing a dc motor provides the required torque to lift the load.
The first stage is designing, where the worm (driver) and worm wheel (driven) is being designed. And threaded screw which is moving vertically over the worm wheel is also being designed. The entire setup is enclosed the box.
LIFTING JACK
Jack (tool), mechanical device used to raise or otherwise exert a force on an object too heavy to deal with by hand. A common example is the automobile jack, which is used to elevate the end of a car by a system of ratchets, gears, and screws.
Lifting jacks are used for leveling or positioning heavy equipment, or for supporting structures. Common types of lifting jacks include bottle, inflatable, pallet, ratchet, scissor, screw, service or floor, toe, and transmission.
GEARS
Gears, toothed wheels or cogs are positive type drives which are used to transmit motion between two shafts or a shaft and a component having linear motion, by meshing of two or more gears. They have advantage over other drives like chains, belts etc. in case of precision machines where a definite velocity ratio is of importance and also in case where the driver and the follower are in close proximity; the downside is that gears are more expensive to manufacture and their operating cost is also relatively high.
BELTS
Belts are used to mechanically link two or more rotating items. They may be used as a source of motion, to transmit power between two points, or to track relative movement.
As a source of motion, a conveyor belt is one application where the belt is adapted to continually carry a load between two points. A belt may also be looped (or crossed) between two points so that the direction of rotation is reversed at the other point.