# Coupling and flange coupling and its design

9 Jan 2018
1 sur 8

### Coupling and flange coupling and its design

• 1. Title:- Flange Coupling Mechanical Engineering Department Submitted By - Name : Rupesh Kumar Section : B Roll No. : 23 Sem : 6th Faculty Advisor - Prof. S. S Kumbhalkar (Prof. Mech. Engg. Dept.) Session 2017-18 Subject –Machine Design - II TAE II: Technical Presentation
• 2. COUPLINGS Couplings are mechanical devices which connect one shaft to another or to couple a drive shaft to a driven shaft. Shaft coupling are used in machinery for next purposes. 1. To provide for the connection of shafts of units that are manufactured separately, such as a motor and a generator, and to provide for disconnection for repairs or alterations, 2. To provide for misalignment of the shafts or to introduce mechanical flexibility. 3. To reduce the transmission of shock loads from one shaft to another. 4. To introduce protection against overloads. 5. T o alter the vibration characteristics of rotating units.
• 3. Couplings Coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power MotorCoupling Pump
• 4. Flange coupling • A rigid flange coupling consists of two cast iron flanges are mounted and keyed on the ends of each shaft and are drawn together by a series of bolts. • For more accurate connection, on the ends of the flange couplings machined the centering surfaces. • The bolts holding the flanges together are sometimes reduced in diameter so that they would readilybreak or shear off in the event of a damaging overload that to serve as a safety device.
• 6. Steps of design Rigid flange coupling • Step:1 Calculate the diameter torque to be transmitted –Mt- use the equation. • Step 2 :Calculate the diameter of the shaft-d-use the equation (Assume di=0) Round off the shaft diameter to R20 series. • Step 3: Based on the diameter of shaft calculated select the coupling and Note down its dimensions. • Step 4 :CHECKING FOR SHEAR STRENGTH OF THE BOLT. 1. Calculate Ft- Refer P.7.106 use equation Ft=2Mt/D2 2. Calculate [Ft] use equation Ft 3. Use equation [Ft] = n x d2/4 x [] ; Where [] is allowable shear stress of shaft material.Compare Ft and [Ft] 4. For safer Design Ft  [Ft] ; If Ft >[Ft] select Next higher coupling and repeat theprocedure from step 3 until Ft  [Ft]
• 7. • Step 5 :CHECKING FOR BEARING STRENGTH OF THE BOLT 1) Note down the value of (b) 2) Calculate (Ft) ; use the equation [Ft] = nd2 b [b] 3) Compare Ft & (Ft) For safer design F (Ft) If Ft> (Ft) select Next higher coupling and repeat the Step 3 & Step 5 Ft  [Ft] • Step 6 :Draw a neat sketch of the coupling with dimensions. Compare the allowable torque (Mt) with the actual torque Mt For safer design Mt  [Mt] If Mt  [Mt] then increase the width & thickness or length of the key to Next higher standard values and repeat from Step 10.1 until Mt  [Mt] • Step:7 Draw a neat sketch of the coupling with dimensions. If flange coupling satisfies all the strength requirements, then it is selected for the application.