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A revolute joint (also called pin joint or hinge joint) is a one- degree-of-freedom 
kinematic pair
In classical mechanics, a kinematic pair is a connection between two physical objects that imposes constraints on their relative movement (kinematics). German engineer Franz Reuleaux introduced the kinematic pair as a new approach to the stud ...
used frequently in mechanism
Mechanism may refer to:
*Mechanism (economics), a set of rules for a game designed to achieve a certain outcome
**Mechanism design, the study of such mechanisms
*Mechanism (engineering), rigid bodies connected by joints in order to accomplish a ...
s and machine
A machine is a physical system that uses power to apply forces and control movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to natural biological macromol ...
s. The joint constrains the motion of two bodies to pure rotation along a common axis
An axis (: axes) may refer to:
Mathematics
*A specific line (often a directed line) that plays an important role in some contexts. In particular:
** Coordinate axis of a coordinate system
*** ''x''-axis, ''y''-axis, ''z''-axis, common names ...
. The joint does not allow translation
Translation is the communication of the semantics, meaning of a #Source and target languages, source-language text by means of an Dynamic and formal equivalence, equivalent #Source and target languages, target-language text. The English la ...
, or sliding linear motion
Linear motion, also called rectilinear motion, is one-dimensional motion along a straight line, and can therefore be described mathematically using only one spatial dimension. The linear motion can be of two types: uniform linear motion, with ...
, a constraint not shown in the diagram. Almost all assemblies of multiple moving bodies include revolute joints in their designs. Revolute joints are used in numerous applications such as door hinge
A hinge is a mechanical bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation, with all ...
s, mechanisms, and other uni-axial rotation devices.
A revolute joint is usually made by a pin or knuckle joint, through a rotary bearing. It enforces a cylindrical contact area, which makes it a lower kinematic pair, also called a full joint. However, If there is any clearance between the pin and hole (as there must be for motion), so-called surface contact in the pin joint actually becomes line contact.
The contact between the inner and outer cylindrical surfaces is usually assumed to be friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of t ...
less. But some use simplified models assume linear viscous damping in the form , where is the friction torque, is the relative angular velocity
In physics, angular velocity (symbol or \vec, the lowercase Greek letter omega), also known as the angular frequency vector,(UP1) is a pseudovector representation of how the angular position or orientation of an object changes with time, i ...
, and is the friction constant. Some more complex models take stiction
Stiction (a portmanteau of the words '' static'' and ''friction'') is the force that needs to be overcome to enable relative motion of stationary objects in contact.
Any solid objects pressing against each other (but not sliding) will require some ...
and the Stribeck effect into consideration.
See also
* Cylindrical joint *Kinematics
In physics, kinematics studies the geometrical aspects of motion of physical objects independent of forces that set them in motion. Constrained motion such as linked machine parts are also described as kinematics.
Kinematics is concerned with s ...
* Degrees of freedom (mechanics)
In classical mechanics, physics, the number of degrees of freedom (DOF) of a mechanical system is the number of independent parameters required to completely specify its configuration or state. That number is an important property in the analysi ...
* Kinematic pair
In classical mechanics, a kinematic pair is a connection between two physical objects that imposes constraints on their relative movement (kinematics). German engineer Franz Reuleaux introduced the kinematic pair as a new approach to the stud ...
* Mechanical joint
* Prismatic joint
A prismatic joint is a one- degree-of-freedom kinematic pair which constrains the motion of two bodies to sliding along a common axis, without rotation; for this reason it is often called a slider (as in the slider-crank linkage) or a sliding ...
References
Kinematics Rigid bodies {{classicalmechanics-stub