Transcript
Clutches
Presented by
Pratyush ranjnan karM-tech manufacturing technologyRegd no.- 163510
Basic idea
Clutches are useful devices with two rotating shafts It connects the driving shaft to a driven shaft, so that the driven
shaft may be started or stopped at will, without stopping the driving shaft
In a drill,,one shaft is driven by a motor and the other is driving a drill chuck. The clutch connects the two shafts so that they can either be locked together and spin at the same speed, or be decoupled and spin at different speeds
Types
Types of Clutches
Positive Clutch
Friction Clutch
Plate Or Disc
Clutch
Single plate clutch
Multiplate Clutch
Cone Clutch
Centrifugal Clutch
Positive Clutch/ dog clutch
It couples two rotating shafts or other rotating components not by friction but by interference.
It is Simple to construct, No heat generated , No slip, Compact ,Low cost.
But it Must be connected when shaft is unloaded. Uses- power press and rolling mills
Friction clutches
Single plate clutch
Multiplate clutch
Centrifugal clutch
Driving shaft
Driven shaft
F=mrω2
ω
ω
Cone clutch
Design and torque transmitted
Area of the ring on contacting surface rrA 2
Axial load on the ring rrpW 2
Frictional resistance offered by ring
rprWFr 2
Frictional torque acting on ring rprrFT rr 22
Torque transmitted is obtained by considering following two assumptions:
a) Uniform pressure theory
b) Uniform wear theory
p = Constant
T R
Rr rprT
0
21
2
2
rrpTR
R
T
r 1
2
2
0
2
Torque transmitted
3231
3
32
32
1
2
RRprpTR
R
32312
2213
2 RRRR
WT
22
21
32
31
32
RRRRWT
Uniform pressure theory
Uniform wear theory In this theory, we are considering that wear which take place
is uniform over the entire contacting surface i.e. p.r = Constant So, p = C/r We know that axial loading acting on the ring is,
Integrating above equation within limits we get, rCW
rrrCrrpW
2
...2...2.
21
21
0
2
22
2
1
2
1
2
RRWC
RRCrCW
rCW
RR
R
R
W
We know that, frictional torque acting on the ring is,
Torque transmitted by single plate clutch can be obtained by integrating the equation within the limits R2 to R1 we get,
rCrrrrCT
rprT
r
r
22
2
2
2
2221
22
21
2
0
0
22
22
2
2
1
2
1
2
1
2
RRCT
RRCrCT
rrCT
rrCT
R
R
R
R
T
r
R
R
T
r
• Power transmitted by single plate clutch is given by,
Where, N = Speed of driving shaft
WattNTP
TP
602.
Any questions
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