3. I. SIMPLE WHEEL & AXLE
V.R= D/d
D=DIAMETER OF EFFORT WHEEL
d= DIAMETER OF LAOD AXLE
4. II. DIFFERAINTIAL AXLE & WHEEL
V.R= 2D/(d1-d2)
D =DIAMETER OF EFFORT WHEEL
d1= DIAMETER OF OF BIGGER AXLE
d2= DIAMETER OF OF SMALLER AXLE
5. III. WESTON’S DIFFERAITIAL PULLY
BLOCK
1) IF NUMBER OF COGS OR TEETH ARE GIVEN
V.R= 2T1/(T1-T2)
T1=NUMBER OF COGS OR TEETH ON BIGGER PULLY
T2= NUMBER OF COGS OR TEETH ON SMALLER PULLY
2) IF D=DIAMETER OF BIGGER & d=DIAMETER OF SMALLER PULLY IS GIVEN
V.R= 2D/(D-d)
6. IV. SINGLE PURCHASE CRAB
V.R.= D/d×T1/T2
D= DIAMETER OF EFFORT WHEEL.
d= DIAMETER OF LAOD DRUM.
T1=NUMBER OF TEETH ON SPUR OR MAIN GEAR.
T2= NUMBER OF TEETH ON PINION.
IF EFFORT HANDLE LENGTH ‘L’ IS PROVIDED INSTEAD OF EFFORT WHEEL.
V.R.= 2L/d×T1/T2
7. V. DOUBLE PURCHASE CRAB
V.R.= D/d×T1/T2× T3/T4
D= DIAMETER OF EFFORT WHEEL.
d= DIAMETER OF LAOD DRUM/LAOD AXLE.
T1=NUMBER OF TEETH ON SPUR ‘A’
T2= NUMBER OF TEETH ON PINION ‘B’ MOUNTED ON INTERMEDIATE SHAFT.
T3= NUMBER OF TEETH ON SPUR ‘C’ MOUNTED ON INTERMEDIATE SHAFT.
T4= NUMBER OF TEETH ON PINION ‘D’ MOUNTED ON EFFORT WHEEL.
IF HANDLE OF LENGTH ‘L’ IS GIVEN,
V.R= 2L/d×T1/T2× T3/T4
L=LENGTH OF HANDLE.
8. VI. WORM & WORM WHEEL
1. IF EFFORT WHEEL IS PROVIDED
V.R. =RT/r
R=RADIUS OF EFFORT WHEEL.
T=NUMBER OF TEETH ON WORM WHEEL.
r= RADIUS OF LOAD DRUM.
2. IF HANDLE IS USED IN PLACE OFEFFORT WHEEL IS PROVIDED.
V.R. =LT/r
L=LENGTH OF HANDLE.
2. IF WORM IS ‘n’ THREADED.
V.R. =RT/nr or =LT/nr
n=NUMBER OF THREAD ON WORM.
9. VII. GEARED PULLY BLOCK
V.R.= T1/T2× T3/T4
D= DIAMETER OF EFFORT WHEEL.
d= DIAMETER OF LAOD WHEEL.
T1=NUMBER OF CAGS ON EFFORT WHEEL ‘A’
T2= NUMBER OF CAGS ON PINION WHEEL ‘B’.
T3= NUMBER OF TEETH ON SPUR WHEEL OR MAIN GEAR ‘D’
T4= NUMBER OF CAGS ON THE LOAD WHEEL ‘C’
IF DIAMETER OF EFFORT WHEEL ‘A’ &LOAD WHEEL ‘C’ IS GIVEN
V.R= D/d× T2/T3
D=DIAMETER OF EFFORT WHEEL ‘A’
d= DIAMETER OF LAOD WHEEL ‘C’
T3= NUMBER OF TEETH ON SPUR WHEEL ‘B’
T2= NUMBER OF TEETH ON PINION WHEEL ‘D’.
10. VIII. SCREW JACK
V.R.= 2 π L/p
L=LENGTH OF EFFORT HANDLE LEVER ARM.
p= PITCH OF THREAD OR PITCH OF SCERW
V.R= π D/p
D=DIAMETER OF EFFORT WHEEL
p= PITCH OF THREAD OR PITCH OF SCERW