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kinematics of machinery by jayakumar pdf free download
Mechanics: It is that branch of scientific analysis which deals with motion, time and force.Kinematics is the study of motion, without considering the forces which produce that motion. Kinematics of machines deals with the study of the relative motion of machine parts. It involves the study of position, displacement, velocity and acceleration of machine parts.Dynamics of machines involves the study of forces acting on the machine parts and the
motions resulting from these forces.
Plane motion: A body has plane motion, if all its points move in planes which are parallel to some reference plane. A body with plane motion will have only three degrees of freedom. I.e., linear along two axes parallel to the reference plane and rotational/angular about the axis perpendicular to the reference plane. (eg. linear along X and Z and rotational about Y.)The reference plane is called plane of motion. Plane motion can be of three types. 1) Translation 2) rotation and 3) combination of translation and rotation.
Introduction to Kinematics
Kinematics is the branch of science which deals with motion without considering the forces which causes the motion. On the other hand, kinetics is the branch of science which also takes forces which causes motion as well as weight and inertia effects in study.
Kinematic Link and Kinematic Pair
Link: It is defined as a machine element having relative motion with respect to other parts of machine element.
Kinematic pair is defined as a joint of two links which permits relative motion between elements or links. Kinematic pair is constituted when there is mechanical contact between them and having arrangement of mechanism.
Lower pair is said to be constituted when two elements have surface contact between them.
Higher pair is said to be constituted when two element have point contact between them.
Kinematic Chain
Kinematic chain is one in which number of links are so connected that relative motion of any point on a page link with respect to any other point on the other page link follows a governing law
L = 2/3(J+2) Where, L = Number of links, J = Number of Joints
or
J = 3/2(L)-2, Where, H = Number of Higher pairs
One Higher pair = Two lower pair
The criterion for a chain to be constrained:
J+H/2 = 3/2(L)-2,
Where, H = Number of Higher pairs and J =Number of binary joints in chain
If R.H.S. = L.H.S. , Chain is said to be locked.
Mechanism
If the one of the page link of constrained kinematic chain is fixed, it results into 'Mechanism'
A mechanism with four links is called simple mechanism. Mechanism with single degree of freedom are having only even number of links.
Real life example is automobile propelling system which contains links in form of piston, connecting rod and cranks shaft to which flywheel and rear tire is attached.
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kinematics of machinery by jayakumar pdf free download
Broadly speaking, we can define machine as a device for transferring and transforming motion and force or power from the input that is, the source to the output that is the load. Let me repeat. Machine is the device for transferring and transforming motion and force from source to the load. The motion needs to be transformed as it is being transferred from the source to the load. The type of transformation that is needed is decided by the nature of the input motion, that is available and the type of output motion that is desired. Some typical examples of the available input motion and desired output motion, we are listing now.It may be the input motion available using the form of continuous rotation, whereas a desired output motion is a rectilinear motion or the vice versa. The input motion is a rectilinear motion and we need the output motion in the form of continuous rotation. Sometimes, the input motion may be continuous rotation, whereas the desired output motion is in the form of to and fro oscillation or again the vice versa. That is, the
available input motion may be to and fro oscillation along a straight line however, the desired output motion may be continuous rotation. Sometimes, both input and output motion may be continuous rotation but they may have to take place at different speed. Sometimes, the input motion may be continuous rotation however, the output motion desired is that of an angular oscillation. It also needs from continuous input rotation to be
transformed into intermittent rotary motion. At this stage, let us talk of a real life machine that is, the most common machine tool which we call a lid. Here, the input motion is available at the shaft of the driving motor, which is the input motor, normally located at bottom left end of the machine.
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Kinematics is the branch of science which deals with motion without considering the forces which causes the motion. On the other hand, kinetics is the branch of science which also takes forces which causes motion as well as weight and inertia effects in study.
Kinematic Link and Kinematic Pair
Link: It is defined as a machine element having relative motion with respect to other parts of machine element.
Kinematic pair is defined as a joint of two links which permits relative motion between elements or links. Kinematic pair is constituted when there is mechanical contact between them and having arrangement of mechanism.
Lower pair is said to be constituted when two elements have surface contact between them.
Higher pair is said to be constituted when two element have point contact between them.
Kinematic Chain
Kinematic chain is one in which number of links are so connected that relative motion of any point on a page link with respect to any other point on the other page link follows a governing law
L = 2/3(J+2) Where, L = Number of links, J = Number of Joints
or
J = 3/2(L)-2, Where, H = Number of Higher pairs
One Higher pair = Two lower pair
The criterion for a chain to be constrained:
J+H/2 = 3/2(L)-2,
Where, H = Number of Higher pairs and J =Number of binary joints in chain
If R.H.S. = L.H.S. , Chain is said to be locked.
Mechanism
If the one of the page link of constrained kinematic chain is fixed, it results into 'Mechanism'
A mechanism with four links is called simple mechanism. Mechanism with single degree of freedom are having only even number of links.
Real life example is automobile propelling system which contains links in form of piston, connecting rod and cranks shaft to which flywheel and rear tire is attached.
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Kinematics is the branch of classical mechanics which describes the motion of points (alternatively "particles"), bodies (objects), and systems of bodies without consideration of the masses of those objects nor the forces that may have caused the motion.Kinematics as a field of study is often referred to as the "geometry of motion" and as such may be seen as a branch of mathematics.Kinematics begins with a description of the geometry of the system and the initial conditions of known values of the position, velocity and or acceleration of various points that are a part of the system, then from geometrical arguments it can determine the position, the velocity and the acceleration of any part of the system. The study of the influence of forces acting on masses falls within the purview of kinetics.
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i need P jaykumar book bcoz its very simple to understand concepts. i love this book
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