Definition:
It can be define like a movable joint of two bodies whose relative movements are both limited.
A series of parts rigidly connected together form a link in a mechanism.
Movements
In a planar mechanism, each link, considering isolated, can have got three independent movements: two of translation, considering the axes ‘x’ and ‘y’ in a coordinate system chosen, and one of rotation around the axe ‘z’, perpendicular to the plane.
A link can have got six independent movements in the space.
Each independent movement, that a body can have, is called degree of freedom.
Restriction
When links form a kinematic joint, they lose the posibility of do certain movements. Their degrees of freedom decrease as well. Limitations introduce in these links’s relative movement are denominate linkage conditions.
Clasification
Kinematic joints are classify according to the number of degrees of freedom.
WACHT OUT!: Outside Spain, kinematic joints are classify in two groups: lower and higher pairs.
