Classified according to the constraints introduced by kinematic pairs. The kinematic pair that introduces a constraint is called a secondary pair, and the kinematic pair introducing the two constraint is called a two order pair, and there are three, four, and five pairs of pairs.Classify according to the geometry of the contact part. It can be divided into cylindrical pair, plane and plane pair, spherical pair, helix pair, etc..All kinematic pairs in a mechanism are low pairs, called low pair mechanisms. At least one pair of kinematic pairs in the mechanism is a high pair, which is called a high pair mechanism.
There are many classifications of sports pairs:According to the form of contact pairs of sports pairs: the surface and surface contact pairs of motion in the contact part of the pressure is low, is called a low pair, and point or line contact motion is called high pair, high pair ratio low, easy to wear.The lower pairs usually have revolute pairs, moving pairs, helical pairs, high pairs with wheels and rails, cams and followers, gears, etc..Classification according to the form of relative motion. A relative motion between the two members of the sports side if plane motion is plane motion, if the space motion is called space motion pair between two members only relative rotation motion is called a rotary pair, between two members only movement pair moving relative to the mobile side.
The basic mechanism consisting of two meshed gears is called a gear pair.This is a kind of sports pair, belonging to a high pair mechanism.A kinematic pair is a movable connection of two components that is in direct contact and can produce relative motion.
