Pin connections are used to enable rotation along a single axis
while constraining axial translation.
• References (constraint rules):
– Axis Alignment to enable
rotation about a single axis.
♦ Use axes or cylindrical
– Translation Reference to
constrain translation along the
♦ Use planes or planar surfaces
• Examples include:
– Door hinge
– Crankshaft in an engine
Figure 1 – Axis Alignment
Figure 2 – Translation Reference
Assembling Components using the Pin Connection
Pin connections are used to enable rotation about a single axis. For example,
a hinge on a door and a crankshaft in a engine both use a Pin connection.
Pin connections require two constraints (rules) that limit their degrees of
freedom about a single axis. These two constraint rules are:
• Axis Alignment — The axes or cylindrical surfaces you select as references
determine the axis of free rotation.
• Translation Reference — The datum planes or planar surfaces you select
with the axis alignment restrict translational movement in the axis direction.