25-08-2017, 09:32 PM
SHAFT COUPLING AND PIPE JOINTS
[attachment=48461]
INTRODUCTION
Coupling is a device that connects two shafts. The shafts which are normally coaxial are
required to be connected so that power can be transmitted from one shaft to another.
Figure 6.1 shows one application of coupling in which the shaft of an electric motor on
the right is joined with the shaft of a worm gear reducer on the left. The essential features
that two discs are mounted on two coaxial shafts and bolted to rotate together are seen
from this Figure 6.1. Yet it is to be noted that in a few practical cases shafts which are
parallel and not coaxial can be joined by Oldham’s coupling and shafts which are
inclined can be joined by universal coupling.
A Coupling Connecting Shafts of an Electric Motor and Worm Gear Reducer
Couplings are temporary fastening devices in the sense that they can be easily dismantled
if and when required.
Rigid and flexible coupling are commonly used to connect coaxial shafts. Clutches which
transmit power by surface friction can be regarded as disengaging type of coupling. Rigid
couplings are used between perfectly coaxial shafts.
Coupling
Machine Drawing
MUFF COUPLING
A muff is a sleeve which can cover two ends of the shafts and in each shaft there is a key
that joins muff with the shaft. The key passes through entire length of the muff and two
aligned keyways in some cases.
Figure 6.2 : A Sleeve Coupling
The muff or sleeve coupling presents problem of fitting the key in the keyway whether a
single key or two keys in two shaft ends are used.
Split muff coupling is made in two halves which are placed on the shaft ends and keys are
tightened with bolts. Proper recesses for tightening the bolts are provided.
Figure 6.3 shows the example.
(a) Split Muff with Bolts
(b) Split Muff Tightened on Two Coaxial Shafts
Split Muff Coupling
Figure 6.4 shows a sleeve coupling. Draw elevation with upper half in section and
side view full.
Figure 6.4 : Sleeve Coupling
Figure 6.5 shows a split muff coupling. Draw elevation with upper half in section
and end view with right half in section along centre line of right hand side bolt.
(a) Draw elevation of sleeve coupling of Figure 6.4 full section.
(b) Draw elevation of muff coupling of Figure 6.5 in full view.
FLANGE COUPLING
It is a rigid coupling used to connect two strictly coaxial shafts. Figure 6.1 shows one
such coupling connecting shafts of electric motor and worm wheel reducer. The coupling
consists of two flanges, usually made in cast iron. The flanges are keyed to the driving
and driven shafts. The flanges are identical in all respects except that one has circular
projection and other has corresponding recess to make a register. When two faces of
flanges are brought in contact the projection fits into recess ensuring perfect coaxiality.
The flanges are then connected with the bolts passing through holes near the periphery.
The faces of the flanges are machine finished true square to shaft axis. The flange
couplings are used for shaft diameters of 18 to 200 mm.
SAQ 4
Figure 6.6 shows two flanges on two perfectly coaxial shafts. Align holes and
assemble the flanges and draw elevation and side views.
Two Flanges on Two Coaxial Shafts, the Flange Bolts are not
PROTECTED FLANGE COUPLING
Flange coupling often refers to unprotected type as shown in Figure 6.6. The bolt heads
and nuts are fully exposed and may present risk to operators. The bolts are protected by
providing cover which extend circumferentially from periphery over the bolt head and
nut. This is known as protected flange coupling.
[attachment=48461]
INTRODUCTION
Coupling is a device that connects two shafts. The shafts which are normally coaxial are
required to be connected so that power can be transmitted from one shaft to another.
Figure 6.1 shows one application of coupling in which the shaft of an electric motor on
the right is joined with the shaft of a worm gear reducer on the left. The essential features
that two discs are mounted on two coaxial shafts and bolted to rotate together are seen
from this Figure 6.1. Yet it is to be noted that in a few practical cases shafts which are
parallel and not coaxial can be joined by Oldham’s coupling and shafts which are
inclined can be joined by universal coupling.
A Coupling Connecting Shafts of an Electric Motor and Worm Gear Reducer
Couplings are temporary fastening devices in the sense that they can be easily dismantled
if and when required.
Rigid and flexible coupling are commonly used to connect coaxial shafts. Clutches which
transmit power by surface friction can be regarded as disengaging type of coupling. Rigid
couplings are used between perfectly coaxial shafts.
Coupling
Machine Drawing
MUFF COUPLING
A muff is a sleeve which can cover two ends of the shafts and in each shaft there is a key
that joins muff with the shaft. The key passes through entire length of the muff and two
aligned keyways in some cases.
Figure 6.2 : A Sleeve Coupling
The muff or sleeve coupling presents problem of fitting the key in the keyway whether a
single key or two keys in two shaft ends are used.
Split muff coupling is made in two halves which are placed on the shaft ends and keys are
tightened with bolts. Proper recesses for tightening the bolts are provided.
Figure 6.3 shows the example.
(a) Split Muff with Bolts
(b) Split Muff Tightened on Two Coaxial Shafts
Split Muff Coupling
Figure 6.4 shows a sleeve coupling. Draw elevation with upper half in section and
side view full.
Figure 6.4 : Sleeve Coupling
Figure 6.5 shows a split muff coupling. Draw elevation with upper half in section
and end view with right half in section along centre line of right hand side bolt.
(a) Draw elevation of sleeve coupling of Figure 6.4 full section.
(b) Draw elevation of muff coupling of Figure 6.5 in full view.
FLANGE COUPLING
It is a rigid coupling used to connect two strictly coaxial shafts. Figure 6.1 shows one
such coupling connecting shafts of electric motor and worm wheel reducer. The coupling
consists of two flanges, usually made in cast iron. The flanges are keyed to the driving
and driven shafts. The flanges are identical in all respects except that one has circular
projection and other has corresponding recess to make a register. When two faces of
flanges are brought in contact the projection fits into recess ensuring perfect coaxiality.
The flanges are then connected with the bolts passing through holes near the periphery.
The faces of the flanges are machine finished true square to shaft axis. The flange
couplings are used for shaft diameters of 18 to 200 mm.
SAQ 4
Figure 6.6 shows two flanges on two perfectly coaxial shafts. Align holes and
assemble the flanges and draw elevation and side views.
Two Flanges on Two Coaxial Shafts, the Flange Bolts are not
PROTECTED FLANGE COUPLING
Flange coupling often refers to unprotected type as shown in Figure 6.6. The bolt heads
and nuts are fully exposed and may present risk to operators. The bolts are protected by
providing cover which extend circumferentially from periphery over the bolt head and
nut. This is known as protected flange coupling.