Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
In this method, the velocity of links in a mechanism are determined using the following steps.
Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Kinematics of Mechanisms - Theory of Machines
The angular velocity ratio theorem states that the angular velocity ratio of two links relative to a third link is inversely proportional to the distances of their common instantaneous centre from their respective centres of rotation.
Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
Locate the fixed and permanent instantaneous centres by inspection and tick mark on the book keeping table.
Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
Kennedy's theorem: "If three bodies have relative motion with each other, then their relative instantaneous centres must lie on a straight line.”
Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
Three types of instantaneous centres are: 1. Fixed instantaneous centres, 2. Permanent instantaneous centres, and 3. Neither fixed nor permanent instantaneous centres.
Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
The following tips may be used in locating the instantaneous centres in a mechanism by visual inspection.
instantaneous centre of rotation
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
In many cases, a body has simultaneously a motion of rotation as well as translation.
Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
We have seen that the total acceleration of a point with respect to another point on a rigid link is the vector sum of its radial and tangential acceleration components
Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
When a point on one link is sliding along another rotating link, then the point is known as coincident point.
Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
A slider-crank mechanism is shown in Fig.2.14(a). Crank OA rotates clockwise with uniform angular velocity ω rad/s.
Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
Fig.2.13(a) snows a four-bar chain ABCD in which AD is fixed and BC is the coupler.
Kinematics of Mechanisms - Theory of Machines
Subject and UNIT: Theory of Machines: Unit I: Kinematics of Mechanisms
In this method, the acceleration of links in a mechanism are determined using the following steps.