Created by: -Manthan Kanani

BRANCH:- Mechanical Engg.

Group Members:- Enroll. No.

Manthan Kanani 140050119028Ishant Kalra 140050119027Pratik Kanani 140050119029Rajneesh Joshi 140050119026

The theory of machines in an applied science which is used to understand the relative motion between the geometry and motions of the parts of a machine or the mechanisms and the study of forces which produce these motion. the study of mechanism involves both their Alalysis as well synthesis.Analysis involves the study of motions and analysis as well as synthesis.Synthesis involves the design of various parts of machines concerning its shape and size, material and to be used and the arrangement of parts so that the resulting machine can perform the desired tasks.

• KinematicsIt is that branch of Theory of Machines which deals with the relative motion between the various parts of the machines with out forces applying to it.• DynamicsIt is that branch of Theory of Machines which deals with the forces and their effects, while acting upon the machine parts in motion.• KineticsIt is that branch of Theory of Machines which deals with the inertia forces which arise from the combined effect of the mass and motion of the machine parts.• StaticsIt is that branch of Theory of Machines which deals with the forces and their effects while the machine parts are at rest. The mass of the parts is assumed to be negligible.

Actual Reciprocating steam machine

Each part of machine which has relative motion to some other part of the machine is known as Kinematic link or an element.A link is not necessary a rigid body but it is a resistance body. A resistant body is one which is capable of transmitting the required motion and forces with negligible deformation.Types of links is shown below.

•The link which do not undergo an appreciable deformation while transmitting the required motion and forces are called rigid link

•The link which are partly deformed while transmitting motion in such a way they do not affected the required transmission of motion are called flexible link

•The links which transmit the motion by fluid pressure as compression are called fluid link

When two kinematic link are connected in such a way that their motion is either completely or successfully constrained , these links are said to form a kinematic pair. Types of Kinematics pairs:

• Nature of relative motion between the links.• Nature of contact between the links.• Nature of mechanical arrangement between the links.

Classification according to nature of relative motion between the links

Slider or prismatic pairTurning or Revolute pair

Screw or Helical pair

Rolling pair Spherical or Globular pair

Classification according to nature of contact between the link

Cam and follower lower pair

Higher pair cylinder and surface

Classification according to the mechanical arrangement

Self closed pairForce closed pair

Binary joint

Quaternary joint

Ternary joint

Binary link

The link which can be attached in mechanism at two points is called as binary link is shown in fig.

Binary joint

When two links are joined at the same connection to form a kinematic chain, the joint is known as binary joint as shown in fig.

InversionsDifferent mechanism by fixing different link of slider crank chain are as follows :First inversion This inversion is obtained when link

FIRST INVERSION (ground body) is fixed. Application- Reciprocating engine, Reciprocating compressor etc...Second inversion This inversion is obtained when link

SECOND INVERSION (crank) is fixed. Application- Whitworth quick return mechanism, Rotary engine, etc...Third inversion This inversion is obtained when link

THIRD INVERSION (connecting rod) is fixed. Application- Slotted crank mechanism, Oscillatory engine etc..,Fourth inversion This inversion is obtained when link

FOURTH INVERSION (slider) is fixed. Application- Hand pump, pendulum pump or Bull engine, etc...

Slider crank chain inversion. When one of the turning pairs of a four-bar chain is replaced by a sliding pair, it becomes a single slider crank chain or simply slider crank chain. This mechanism is composed of three important parts: The crank which is the rotating disc, the slider which slides inside the tube and the connecting rod which joins the parts together. As the slider moves to the right the connecting rod pushes the wheel round for the first 180 degrees of wheel rotation. When the slider begins to move back into the tube, the connecting rod pulls the wheel round to complete the rotation.

FIRST INVERSION

Gnome engine Whitworth quick return mehanism

SECONDINVERSION

THIRD INVERSION

FOURTH INVERSION

Hand pump

The Scotch yoke (also known as slotted link mechanism) is a reciprocating motion mechanism, converting the linear motion of a slider into rotational motion, or vice versa. The piston or other reciprocating part is directly coupled to a sliding yoke with a slot that engages a pin on the rotating part. The location of the piston versus time is a sine wave of constant amplitude, and constant frequency given a constant rotational speed

This is used to connect two parallel shafts when they are not co-axial and the distance between their centre lines is small

Oldham’s coupling

Scotch mechanism

A trammel of Archimedes is a mechanism that traces out an ellipse. It consists of two shuttles which are confined ("trammelled") to perpendicular channels or rails, and a rod which is attached to the shuttles by pivots at fixed positions along the rod. As the shuttles move back and forth, each along its channel, the end of the rod moves in an elliptical path. The semi-axes a and b of the ellipse are the distances between the end of the rod and the two pivots. An ellipsograph is a trammel of Archimedes intended to draw, cut, or machine ellipses, e.g. in wood or other sheet materials. An ellipsograph has the appropriate instrument (pencil, knife, router, etc.) attached to the rod. Usually the distances a and b are adjustable, so that the size and shape of the ellipse can be varied.

Elliptical mechanism

Created by :-MANTHAN KANANI