translation – movement along x, y, and z axis (three degrees of freedom) rotation – rotate about...
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Translation – movement along X, Y, and Z axis (three degrees of freedom)
Rotation – rotate about X, Y, and Z axis (three degrees of freedom)
Point
X
Y2 DOF
YZ
3 DOF
X
Rigid Body
Y
X
3 DOF
X
YZ
6 DOF
One Link (3DOF) Two Links (6DOF)
One Link (3DOF)
Two Links + One Joint (4DOF)
The Revolute joint (pin or hinge joint) - one degree of freedom(Reduces 2 degrees of freedom in )It allows pure rotation between the two links that it connects (R joints)
18
The Sliding joint (prism or piston joint) - one degree of freedom(Reduces 2 degrees of freedom)It allows linear sliding between the two links that it connects (P joint)
DOF = degree of freedom (Planar)L = number of links, including ground link
J1 = number of 1 DOF joints
J2 = number of 2 DOF joints
DOF ≤ 0 structure
mechanismDOF > 0
DOF = 3(L – 1) – 2J1 – J2
L = 4 , J1 = 4 pin connections, J2 = 0
DOF = 3(L – 1) – 2J1 – J2
DOF = 3(4 – 1) – 2(4) – (0) = 1
Four Bar mechanism
Slider crank mechanism
L = 4 , J1 = 3 pin connections + 1 slider = 4 J2 = 0
DOF = 3(4 – 1) – 2(4) – (0) = 1