CH 17: Flexible Mechanical Elements
Flexible mechanical elements (belts, chains, ropes) are used in conveying systems and
to transmit power over long distances (instead of using shafts and gears).
The use of flexible elements simplifies the design and re
CH16: Clutches, Brakes, Couplings and Flywheels
These types of elements are associated with rotation and they have in common the
function of dissipating, transferring and/or storing rotational energy.
Clutches and Brakes perform the same function where tw
CH 14: Spur and Helical Gears
This chapter is devoted to analysis and design of spur and helical gears such that they
will resist bending failure of teeth and pitting failure of tooth surfaces.
The Lewis Bending Equation
The Lewis equation is used to esti
CH 13: Gears-General
Types of Gears
There are four principal types of gears:
Spur gears: (Fig. 13-1) the simplest type of gears. The teeth are parallel to the
axis of rotation. It transmits rotation between parallel shafts.
Helical gears: (Fig. 13-2) th
CH 12: Lubrication and Journal Bearings
The purpose of lubrication is to reduce friction, wear and heating of machine parts
moving relative to each other.
In sleeve bearing, a shaft (or Journal) rotates within a sleeve (or bushing) and the
CH 15: Bevel and Worm Gears
Bevel Gears - General
Bevel gears are classified as follows:
Straight Bevel Gears: (Fig. 13-35) used for pitch line velocities up to 5m/s, noise
level is high.
Spiral Bevel Gears: (Fig. 15-1) used for higher speeds, noise lev
CH 10: Mechanical Springs
Springs allow controlled application of force or torque; also they can be used for
storing and releasing energy.
In general, springs may be classified as: wire springs, flat springs, and special shaped
Wire springs (rou
CH 11: Rolling-Contact Bearings
Also called antifriction bearings or rolling bearings.
The starting friction is about twice the running friction.
Different from journal bearings in that the load is transferred by elements in rolling
contact rather than s
CH 9: Design of Permanent Joints
This chapter introduces permanent joining methods which include: welding, soldering,
cementing, bonding, etc.
Permanent joining usually leads to significant savings over non-permanent joining
(because of the elimination of
CH 8: Screws, Fasteners, and the Design of Non-Permanent Joints
This chapter introduces non-permanent joining elements such as bolts, nuts, setscrews
rivets, pins, keys, etc.
It also introduced power screws which changes angular motion to linear motion, w
CH 6: Fatigue Failure Resulting from Variable Loading
Some machine elements are subjected to static loads and for such elements static
failure theories are used to predict failure (yielding or fracture). However, most
machine elements are subjected to var
CH 3: Load and Stress Analysis
Machine elements carry different types of loads (concentrated, distributed, axial,
lateral, moments, torsion, etc.) according to the function and configuration of each
element. These loads cause stresses of different types a
CH 4: Deflection and Stiffness
Stress analyses are done to ensure that machine elements will not fail due to stress
levels exceeding the allowable values. However, since we are dealing with deformable
bodies (not rigid), deflections should be considered a
CH 5: Failures Resulting from Static Loading
A static load is a stationary (constant magnitude, location and direction) force or
couple (moment or torque) applied to a member.
Failure in machine design means that a part become permanently distorted (i.e.
CH 1: Introduction
Science explains what is; Engineering creates what never was.
Laws of nature
System, Input, Output
System Input, Output, Laws
Output System, Input, Laws
Inverse Analysis Input
CH 2: Materials
Choosing the appropriate material is an important step in mechanical design.
Material Strength and Stiffness
Standard tensile test is used to determine many of the mechanical
properties of the materials.
- Load, , and deflection,
, are rec