JointsComponents that constrain the motion between two frames 
Prismatic joint (1 translational degreeoffreedom, 2 potential states, optional axis flange) 

Revolute joint (1 rotational degreeoffreedom, 2 potential states, optional axis flange) 

Revolute joint that is described by 2 positional constraints for usage in a planar loop (the ambiguous cutforce perpendicular to the loop and the ambiguous cuttorques are set arbitrarily to zero) 

Cylindrical joint (2 degreesoffreedom, 4 potential states) 

Universal joint (2 degreesoffreedom, 4 potential states) 

Planar joint (3 degreesoffreedom, 6 potential states) 

Spherical joint (3 constraints and no potential states, or 3 degreesoffreedom and 3 states) 

Free motion joint (6 degreesoffreedom, 12 potential states) 

Free motion joint with scalar initialization and state selection (6 degreesoffreedom, 12 potential states) 

Spherical  spherical joint aggregation (1 constraint, no potential states) with an optional point mass in the middle 

Universal  spherical joint aggregation (1 constraint, no potential states) 

Ideal 3dim. gearbox (arbitrary shaft directions) 

Joint (no mass, no inertia) that describes an ideal rolling wheel (rolling on the plane z=0) 

Joint (no mass, no inertia) that describes an ideal rolling wheel set (two ideal rolling wheels connected together by an axis) 

Components that aggregate several joints for analytic loop handling 

Components that define joints by constraints 

Components used for analytic solution of kinematic loops (use only if you know what you are doing) 
This information is part of the Modelica Standard Library maintained by the Modelica Association.
This package contains joint components, that is, idealized, massless elements that constrain the motion between frames. In subpackage Assemblies aggregation joint components are provided to handle kinematic loops analytically (this means that nonlinear systems of equations occurring in these joint aggregations are analytically solved, i.e., robustly and efficiently).
Model  Description 

Prismatic  Prismatic joint and actuated prismatic joint
(1 translational degreeoffreedom, 2 potential states) 
Revolute  Revolute and actuated revolute joint
(1 rotational degreeoffreedom, 2 potential states) 
Cylindrical  Cylindrical joint (2 degreesoffreedom, 4 potential states) 
Universal  Universal joint (2 degreesoffreedom, 4 potential states) 
Planar  Planar joint (3 degreesoffreedom, 6 potential states) 
Spherical  Spherical joint (3 constraints and no potential states, or 3 degreesoffreedom and 3 states) 
FreeMotion  Free motion joint (6 degreesoffreedom, 12 potential states) 
SphericalSpherical  Spherical  spherical joint aggregation (1 constraint,
no potential states) with an optional point mass in the middle 
UniversalSpherical  Universal  spherical joint aggregation (1 constraint, no potential states) 
GearConstraint  Ideal 3dim. gearbox (arbitrary shaft directions) 
MultiBody.Joints.Assemblies  Package of joint aggregations for analytic loop handling. 
MultiBody.Joints.Constraints  Package of components that define joints by constraints 