Lifting heavy loads with the westons differential pulley lifting. It is expected that it is expected that the efficiency will be 80% when raising a load of 500 n and the effort must be 25 n. Westons differential pulley block, various lifting. It is operated by pulling upon the slack section of a continuous chain that wraps around pulleys.
Westons differential pulley block simple machines in engineering. A differential axle as shown above has two diameters 75 mm and 100 mm. Powerhouse museum, sydney, australia 2003451 differential pulley block, large and small sheaves, 2 ton. Westons differential pulley block video lecture from chapter simple machines in engineering mechanics for first year engineering students. The upper block a has two pulley p 1 and p 2, one having its diameter a little large than that of the other, these pulleys turn together as one pulley, i. Discourse on simple wheel and axle, wheel and differential axle, and worm. In this webcast, we explain the reason why it is called differential pulley. This video explains the operation of a differential pulley system, known as a weston differential pulley. Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. Figure illustrates a westons differential pulley block. This has previously been done to a limited extent by the employment of large sprocket wheels and gearing, but only in such form as to be almost useless for practical purposes.
In a weston s pulley block the radius of the smaller wheel is. The relative size of two connected pulleys determines the maximum weight that can be lifted by hand. A single rope or string or chain passes around the pulleys as. Weston s differential pulley block video lecture from chapter simple machines in engineering mechanics for first year engineering students. The lower block b also carries a pulley, to which the load is attached. Weston s differential pulley block simple machines in engineering mechanics duration. The lower block contains only one pulley which moves up and down and its frame supports the load to be lifted. Figure illustrates a weston s differential pulley block. For example two wheels in each block will give 4 ropes. Weston s recent improvement is to extend the utility of the differential pulley block to the handling of weights of from 3 to 10 tons, or, if necessary, even greater ones. Differential pulley lifting mechanical advantage equations. Westons differential pulley block simple machines in.
Weston differential pulley block is a special type of pulley system, which is normally used to hoist very large masses to a small distance, for. Mechanical advantage differential pulley calculator. Explain mechanical power make calculations involving mechanical power. A differential pulley, also called weston differential pulley, sometimes chain hoist or. A differential pulley, also called weston differential pulley, sometimes chain hoist or colloquially chain fall, is used. This is a special study on simple pulley and pulley block and their. Pulleys differential axles weston differential pulley geared systems winches calculate the force required to slide a block on an inclined plane. A differential pulley, also called weston differential pulley, sometimes chain hoist or colloquially chain fall, is used to manually lift very heavy objects like car engines. Differential wheel and axle simple machines engineering mechanics.1423 74 951 706 157 507 1228 635 1403 908 545 1202 874 344 1346 75 41 515 1496 1499 423 1087 124 399 1060 1068 966 1482 898 1334 1418 360 1257 434 1160 823 1419