BEAM ENGNE

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LinkA component forming a part of a chain; generally rigid with provision at each end for connection to two other links

MechanismA combination of rigid bodies (links) connected by kinematic pairs.

Kinematic pairA joint which is formed by the contact between two bodies and allows relative motion between them.

MachineA collection of mechanisms which transmit force from the source of power to the resistance to be overcome.

TERMINOLOGY

MECHANISM

When a kinematic chain with one of its link is fixed, is called a mechanism.

A mechanism is a skeleton diagram of a machine to transmit the definite motions between various links.Example: type writer, clock work, etc.

Four Bar Chain or Quadric Cycle Chain

•It consists of four links• Each of them forms a turning pair at A, B, C and D•. The four links may be ofdifferent lengths.

Grashof ’s lawThe sum of the shortest and longest link lengths should not begreater than the sum of the remaining two link lengths if there is to becontinuous relative motion between the two links.

What is inversion?Inversion is the

method of obtaining different mechanisms by fixing different links in a kinematic chain, is known as inversion of the mechanism.

INVERSIONS of FOUR BAR CHAIN

BEAM ENGINE (CRANK OR LEVER

MECHANISM)

COUPLING ROD OF A LOCOMOTIVE(DOUBL

E CRANK MECHANISM)

WATTS INDICATOR (DOUBLE LEVER

MECAHNISM)

Inversions of four bar kinematic chainThe four bar chain mechanism consists of

four turning pairs.The four different mechanisms are obtained

by fixing one link at a time.Kinematically, all four inversions of kinematic

chain are identical.However there mobility can be varied by

suitably changing the proportions of lengths of various links.

BEAM ENGINEA part of the mechanism of a beam engine (also

known as crank and lever mechanism).Beam engine introduced in Wanlockhead in 1745Consists of 4 links.

The purpose of this mechanism to convert rotary motion into reciprocating machine..

The crank rotates about the fixed center A, the lever oscillates about a fixed Centre D. The end E of the lever CDE is connected to a piston rod which reciprocates due to the rotation of the crank.

Working principle

BEAM ENGINE ( CRANK AND LEVER MECHANISM)

Beam engine mechanism

Applications It is used to draw out water from mines, as well

as to pump water into canals. This mechanism is widely used in steam engines

but nowadays it is used in water pumps, oil rings, specially sewing machine.

It is type of steam engine where a pivoted overhead beam is used to apply the force from a vertical piston to a vertical connecting rod

It is basically 6 link mechanism that converts rotary motion of crank into reciprocating motion of piston.

Degree of freedom(DOF)DOF of a mechanical system is the no of

independent parameters that defines its configuration.

n = 3 (l – 1) – 2 j – hIt has two degree of freedom i.e rotation

of link about axis perpendicular to the plan and vertical motion.

Stuart Beam EngineThis is a design perfected by James Watt in 1794.

Example of beam engine

A watt engine : showing entry of steam and water

THANKSPRESNTED BY

kavinder(kavi)