manufacturing of disc couplings 2 - craZZyden.com

badwaterreflectiveUrban and Civil

Nov 29, 2013 (3 years and 8 months ago)

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MANUFACTURING OF DISC
COUPLINGS

CH.UMESH CHANDRA

08B61A0311


ABSTRACT

Disc

couplings

transmit

power

through

tensile

force

between

alternating

driving

and

driven

bolts

on

a

common

bolt

circle
.

The

disc

coupling

consists

of

two

hubs,

two

flexible

discs

and

a

spacer
.

The

main

aim

of

this

project

is

to

study

and

examine

design

and

visually

observe

the

manufacturing

process

of

disc

couplings
.


INTRODUCTION

A

coupling

is

a

device

used

to

connect

two

shafts

together

at

their

ends

for

the

purpose

of

transmitting

power
.



To

reduce

transmission

shock

loads

from

one

shaft

to

another
.


To

introduce

protection

against

overloads
.


To

provide

for

misalignment

of

the

shafts

or

to

introduce

mechanical

flexibility
.


To

provide

disconnection

for

repairs

or

alterations
.


BASIC TYPES OF COUPLINGS

1
.
Rigid

couplings


-

Sleeve

or

Muff

coupling


-

Clamp

or

Split
-
muff

coupling


-

Flange

coupling

2
.
Flexible

couplings


-

Bushed

pin

type

coupling


-

Universal

coupling


-

Oldham

coupling



DISC COUPLINGS

Disc

couplings

transmit

torque

from

a

driving

to

a

driven

bolt

tangentially

on

a

common

bolt

circle
.

Torque

is

transmitted

between

the

bolts

through

a

series

of

thin,

stainless

steel

discs

assembled

in

a

pack
.

Misalignment

arises

from

the

flexibility

that

comes

from

the

length

of

material

between

the

bolts
.

Misalignment

is

taken

through

bending

in

the

link

between

the

bolt

holes
.



DESIGN REVIEW

A)

Flexing

Element

Design
:

In

the

design,

the

flexible

elements

have

a

polygonal

outer

profile

with

a

circular

central

hole
.





B)

Coupling

bolt
:


The

coupling

bolts

in

the

design

are

manufactured

out

of

high

tensile

steel

and

are

adequately

sized

to

transmit

torque

through

friction

rather

than

shear
.

TYPES OF MISALIGNMENT

There are three types of misalignments:

1. Axial Misalignment

2. Angular Misalignment

3. Parallel
-
offset Misalignment


SELECTION PROCEDURE


Review the initial requirements for a flexible coupling and
select the type of coupling that best suits the system.


Obtain the flexible coupling’s characteristic information so
the interactions of the coupling with the system can be
checked to ensure compatibility.


The coupling selector should obtain the values:



1. Horsepower


2. Operating speed


3. Offset misalignment


4
.
Torque


5. Angular misalignment etc.



MANUFACTURING PROCESS

The

main

parts

of

the

flexible

disc

coupling

are

two

hubs,

a

spacer

and

two

flexible

discs
.










DISC

MANUFACTURING
:

The

discs

are

manufactured

from

spring

steel

because

spring

steel

can

withstand

wide

range

of

temperatures

and

has

high

yield

strength
.

First,

the

heavy

sheet

metal

gauges

are

taken

and

cut

according

to

the

required

square

shape

depending

on

the

number

of

holes
.


A

blanking

die

is

used

to

cut

or

shape

the

metal

laminations

by

making

them

flat

in

one

operations
.

These

flat

sheets

are

brought

together

by

pressing

them

against

each

other

using

hydraulic

press
.

The

ends

of

the

formed

metal

sheets

are

grinded

for

safety

purpose

and

also

for

accurate

finishing

and

high

efficiency
.



After

that

holes

are

drilled

at

the

marked

places

with

the

help

of

a

drilling

machine

and

these

holes

are

finished

to

perfection
.

Washers

are

induced

into

each

and

every

hole

to

fit

the

bolts

perfectly
.




HUB AND SPACER MANUFACTURING:

The

hub

and

spacer

are

manufactured

from

cast

iron
.

Cast

iron

as

a

raw

material

undergoes

rust

removal

process

and

undergoes

different

operations

in

lathe

machine,

drilling

machine,

grinding

machine,

milling

machine

and

CNC

machine

to

form

a

standard

hub

and

spacer

according

to

the

required

dimensions
.

First,

the

cylindrical

shaped

iron

bar

undergoes

the

turning

operation

where

the

upper

layer

of

the

cylindrical

bar

is

removed

so

that

the

bar

is

clean

from

all

impurities

such

as

rust
.




The holes at the two ends of the sections are drilled either on a
drilling machine or using drill bits which are held stationary in the
tail stock or tool turret of the lathe.


CNC milling machine is used for the milling operations to achieve
high complex geometry and high product quality.

Also the ability of the spindle to move in the z
-
axis is the main
reason to use CNC milling machines in the coupling manufacturing.



The

hub

is

manufactured

on

the

lathe

machine

involving

operations

such

as

turning,

rough

turning

and

the

hole

part

is

done

on

a

drilling

machine
.



Also a slotting machine is used to slot a key way in the hub
.

COUPLING FAILURES,QUALITY
PLAN AND INSPECTION

1
.

Disc

failures

such

as

Misalignment

failure,

Fatigue

failure,

elongated

bolt

holes
.

2
.

Distorted

disc

packs

such

as

Compression

damage

of

a

disc

pack,

Elongation

damage

of

a

disc

pack
.

3
.

Torque
-
overload

failure
.


Visual

inspection

must

be

carried

out

to

check

broken

disc,

loose

bolts

and

they

must

be

replaced
.


Chemical

Mechanical

NDT

machining

is

the

manufacturing

process

carried

out

as

a

part

of

the

quality

plan
.


CONCLUSION

Advances in couplings is a continuing process as the
needs of power transmission increase. Disc couplings
have numerous of advantages such as low maintenance,
good dynamic balance, no lubrication cost, high
torsional rigidity and is used in many application such
as compressors, generators etc.

Hence in future, disc couplings play a vital role in many
applications.