Key Points to remember

• Internal combustion is the most widely used prime mover which converts heat energy in the fuel into mechanical energy in the form of rotation. An internal combustion engine consists of several parts, the machine design deals with applying the basic principles to key parts such as Cylinder and cylinder liners,Piston,piston rings,piston pin, connecting rod, big and small end bearings,crankshafts etc.

Key Points to Remember

• A Pressure vessel is defined as a container pipeline which is used for storing carrying fluids under pressure
•  An unfired Pressure vessel is defined as a container or pipeline which is used for storing carrying steam, gases or liquid at a pressure above atmospheric pressure.

KEY POINTS TO REMEMBER

• A cylinder is said to be 'THIN' if the ratio of its inner diameter to the thickness of wall is more than 20. And when it below 20 then it is termed as thick cylinder.
• A thin cylinder is subjected to two principal stresses, Circumferential stresses (along circumference) and longitudinal stress (along length). 

Important Points to Remember 

• The objective of material handling system the moment of materials from one point to another point within the plant
• The material handling system consists of three activities one picking up the material second transporting the load and third sitting down the Lord
• A good material handling system should have, accuracy in low transportation, low operating and initial cost, easy to operate and maintain, and it should give operational safety.

Theory Questions and Answers
Q.1. What is the function of gearbox in a machine tool? or What is the need of a multispeed bearbox in a machine tool or automobile?

Kye points :

• Bearing is a mechanical element whose function is to support two machine parts and which permits relatve motion between them with minimum friction.

• Bearings are classified on the basis of nature of contact as Sliding contact bearings and Rolling contact bearings.

• Rolling contact bearings are further classified as Ball beaings and roller bearing.

Theory Questions and Answers on Sliding Contact Bearings

Q.1. State the Assumptions made in Petroff's equation. Derive the Petroff's equation. Also state the limitations of PEtroff's equation.

Ans :

Petroff equation is used to determine the coefficient of friction in hydrodynamic bearing,  it is based on following assumptions,

WORM and WORM gear :

A worm drive is an arrangement of gears in which a worm ( In the form of screw) meshes with a worm wheel (in the form of spur gear). A worm gear can transmit motion (speed reduction) as well as it can transmit high torque. Another distinguishing feature of worm gear unit is that they transfer motion in 90 degrees.

Q.1. Where bevel gears are used? what is their speciality? What are different types of bevel gears?

Q.1. Compare the contact between mating of spur and helical gears teeth? Which is better?