Drivetrain Hub | Gears App

Gears App is designed to make the modeling process easy, intentionally limiting the amount of fidelity required to model and simulate a system of gears.  A functionality where this philosophy can be noticed is in the modeling of constraints, i.e. the relationships between parts.

Two key rules exist for part constraints:

  1. All parts are free to rotate, unless specified otherwise.
  2. All parts are in the ground reference frame, unless specified otherwise.

For item (1), this means a revolute constraint implicitly exists between each part and its reference frame, i.e. as though it is mounted on a bearing.  For item (2), any part can be moved to the reference frame of another part.  This is typically done for the following use cases:

  1. Mounting a gear to a shaft.
  2. Mounting a gear to a carrier.

For item (a), it is likely a weld or clutch constraint will be needed between the gear and shaft, depending on your gearbox architecture.  For item (b), this approach is required to correctly model a planet gear that precesses with a planetary carrier.