cotter & knuckle joints

ACTIVE LEARNING ASSIGNMENT PRESENTATIONMACHINE DESIGN & INDUSTRIAL DRAFTING

(2141906)

TOPICECCENTRIC LOADING, COTTER & KNUCKLE

JOINTS

PREPARED BYMECHANICAL – 4B2

DEVANSU KHORASIYA (150120119066)

GUIDED BYPROF. HARDIK PATEL

PREPARED BY : DEVANSU KHORASIYA(GIT-150120119066)

WHICH CONTENT WE WILL BE GOING TO LEARN IN THIS PRESENTATION..

1.ECCENTRIC LOADING2.COTTER JOINTS3.KNUCKLE JOINTS

Lets Starts The Journey…


WHAT IS CENTRIC & ECCENTRIC LOADING ??


COTTER JOINTS :-A cotter is a flat wedge-shaped piece of steel as shown in figure. This is used to connect rigidly two rods which transmit motion in the axial direction, without rotation.These joints may be subjected to tensile or compressive forces along the axes of the rods. Examples of cotter joint connections are: connection of piston rod to the crosshead of a steam engine, valve rod and its stem etc.

A typical cotter joint is as shown in figure. One of the rods has a socket end into which the other rod is inserted and the cotter is driven into a slot, made in both the socket and the rod.


•Let P = Load carried by the rods,•d = Diameter of the rods,•d1 = Outside diameter of socket,•d2 = Diameter of spigot or inside •diameter of socket,•d3 = Outside diameter of spigot collar,•t1 = Thickness of spigot collar•d4 = Diameter of socket collar,

•c = Thickness of socket collar,•b = Mean width of cotter,•t = Thickness of cotter,•l = Length of cotter,•a = Distance from the end of the slot to the end of rod,•σt = Permissible tensile stress for the rods material,•τ = Permissible shear stress for the cotter material, and•σc = Permissible crushing stress for the cotter material.


A Cotter Joints Is A Flat Wedge Link Piece Of Steel Of Rectangular Cross Section Which Is Inserted Through The Rods At High Angle To Their Axes .It Is Uniform In Thickness But Tapering In Width , Generally On One Side Only. Usually The Taper Is 1 In 30. When A Special Arrangement Like A Set-screw Is Provided For Keeping The Cotter From Slackening Its Taper May Be As Large As 1 In 7. The End Of The Cotter Are Made Narrow To Facilitate The Hammering For Fixing And Removing. Cotter Joins Are Generally Use To Fasten Rigidly Two Rod S Which Is Subjected To Tensile Or Compressive Stress Along Their Axes. This Joint Is Used To Connect Two Circular Rods.This Joint In Not Suitable Where The Member Are Subjected Under Rotation.PREPARED BY : DEVANSU KHORASIYA(GIT-

150120119066)

REMIND THESE POINTS

FAILURES :-

FAILURES CONTINUE...

DIAGRAM FOR FAILURES

HERE IS THE EQUATIONS OF FAILURES :-

KNUCKLE JOINT :-Two or more rods subjected to tensile and compressive forces are fastened togetherTheir axes are not in alignments but meet in a pointThe joint allows a small angular moment of one rod relative to anotherIt can be easily connected and disconnectedApplications: Elevator chains, valve rods, etc


SIMPLE ASSEMBLING OF KNUCKLE JOINT


These joints are used for different types of connections e.g. tie rods, tension links in bridge structure. In this, one of the rods has an eye at the rod end.The other one is forked with eyes at both the legs. A pin (knuckle pin) is inserted through the rod-end eye and fork-end eyes and is secured by a collar and a split pin.These joints are used for different types of connections e.g. tie rods, tension links in bridge structure.In this, one of the rods has an eye at the rod end and the other one is forked with eyes at both the legs.A pin (knuckle pin) is inserted through the rod-end eye and fork-end eyes and is secured by a collar and a split pin.Normally, empirical relations are available to find different dimensions of the joint and they are safe from design point of view. The proportions are given in the figure.PREPARED BY : DEVANSU KHORASIYA(GIT-150120119066)

FAILURES :-

FAILURES CONTINUE...

APPLICATIONS OF COTTER Simple to design and

manufacture Simple to assemble and

dismantle Very high tightening force

due to wedge action which prevents loosening of parts in service

Connection of the piston rod with the cross heads

Joining of tail rod with piston rod of a wet air pump

Foundation bolt Connecting two halves of

fly wheel (cotter and dowel arrangement)

Simple To Design And Manufacture Fewer Parts -Less Cost More Reliability Simple To Assemble And DismantleJoints Between The Tie Bars In A Roof Trusses.Between The Links Of Suspension Bridge.In Valve Mechanism Of A Reciprocating Engine.Fulcrum For The Levers.Joints Between The Links Of A Bicycle Chain.

APPLICATIONS OF KNUCKLE


APPLICATION OF COTTER JOINT


APPLICATION OF KNUCKLE JOINT


AT THE LAST…….One Humble Request to all of YOU….

Make sure Your House, School, College, Society, Road, State, Nation, World is Neat and Clean……PREPARED BY : DEVANSU KHORASIYA(GIT-150120119066)

THANK YOU GUYS FOR LISTINING ME……

PRESENTATION & DESIGNED BYDEVANSU KHORASIYA (150120119066)

MY AIM IS….

CLEAN INDIAGREEN INDIA &MAKE IN INDIA.


cotter & knuckle joints

Engineering