View Factor Orientation (or View factor or shape factor) plays an important role in radiation heat transfer. View factor is defined as, "fraction of radiation leaving surface 'i' and strike 'j' ". Summation Rule (View Factor) If there is are similar surfaces 'i' and 'j' , then: Blackbody Radiation Exchange Radiation Exchange between Opaque, Diffuse, Gray surfaces in an Enclosure 1. Opaque 2. Surfaces 3. Two surface enclosure Radiation Shield It is used to protect surfaces from radiation act like a reflective surface. References: Material from Class Lectures + Book named Fundamentals of Heat and Mass Transfer by Theodore L. Bergman + My knowledge. Photoshoped pics are developed. Some pics and GIF from Google. Videos from YouTube ( Engineering Sights ).
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Cotter and Knuckle Joints
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Cotter Joints
A temporary fastener used to connect rigidly two co-axial rods (or bars) which are subjected to axial tensile or compressive forces.
Cotter ↣ A flat wedge shaped piece of rectangular cross-section of uniform thickness and its width is tapered for an easy adjustment.It is made of steel.
Used in connecting piston rod to cross-head of reciprocating steam engine.
Inserted ⊥ to the axis of shaft.
Strength of key < Cotter strength ↣ because of removing material.
We add taper on top of key while we add taper on top, bottom but along width side of cotter.
Types of Cotter Joint
1. Sleeve and Cotter Joints
Simplest of all cotter joints and is used to fasten two round rods/bars.
Rectangular cross-section area, tapered both sides along width.
We add cotter pin ⊥ to the axis of shaft and add sleeve to shaft and then add pin.
It has better strength than Socket and Spigot Cotter joint.
Taper in cotter is 1 in 24.
2. Gib and Cotter Joints
It is used to join two square rods but round rods can be joined with suitable modification.
One end of rod is U-fork shaped and the other is of square end.
Gib ↣ C-shaped added to provide strength to joints (for greater load bearing area and holding force between cotter and rods).
Lug ↣ one side of gib is tapered and the other is straight with 2 rectangular projections which get U-shaped rod and rod together then we add cotter pin.
3. Socket and Spigot Cotter Joint
Used to connect 2 circular rods to carry both tensile and compressive loads.
One end is provided with a socket by enlarging its end.
Spigot ↣ Other rod is inserted into socket.
Design of Socket and Spigot Cotter Joint
Knuckle Joint
Mechanical joint used to connect two rods which are under a tensile load.
One of the rod can be positioned through some angle about the plane containing rods.
Cross-section of Knuckle is circular.
It contains two ends, end of one rod is made into fork (double eye) and the other rod end is made into eye.
Pin is inserted and they are held by means of collar and a taper pin.
Design of Knuckle Joint
References:
Material from Class Lectures + Book named Mechanical Engineering Design by Shigley (8th Edition) + my knowledge.
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