Gear Pair
Use the Gear Pair node for 2D and 3D components to create a connection between gears of the types Spur Gear, Helical Gear, or Bevel Gear in such a way that, at the contact point, they have no relative motion along the line of action. The remaining displacements and rotations of both the gears are independent of each other.
If the Line contact option is chosen in the Contact model, one additional constraint is added at the contact point to restrict the relative rotation about a line joining the two gear centers.
When Friction is included for a gear pair, frictional forces in the plane perpendicular to the line of action are added on both the gears.
Sketch
This section shows a sketch of a gear pair. The sketch highlights the coordinate system attached to both the gears, the coordinate system attached to the gear tooth, the line of action, and other relevant input parameters.
Gear Selection
Select Wheel and Pinion from the list of gears. You can select any Spur Gear, Helical Gear, or Bevel Gear node that is defined for the model.
Line of Action
Define the line of action by specifying Obtained by rotation of tangent in — Clockwise direction, or Counterclockwise direction.
Select the Clockwise direction option in the following cases:
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Wheel is the driver and the Wheel has positive rotation about its own axis.
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Pinion is the driver and the Wheel has negative rotation about its own axis.
Select the Counterclockwise direction option in the following cases:
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Pinion is the driver and the Wheel has positive rotation about its own axis.
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Wheel is the driver and the Wheel has negative rotation about its own axis.
The gear pair sketch in the Sketch section is updated based on the selection and shows the line of action for both cases.
Contact Model
Define the contact model for a gear pair in this section.
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Select the Configuration — Parallel or intersecting or Neither parallel nor intersecting. The Configuration is always set to Parallel or intersecting for spur and bevel gears. For helical gears, you can select the Configuration as Parallel or intersecting (for parallel axis helical gears) or Neither parallel nor intersecting (for crossed axis helical gears).
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For Parallel or intersecting, select the Contact model — Point contact, or Line contact. For Neither parallel nor intersecting the Contact model is always set to Point contact.
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For Parallel or intersecting, enter Contact point offset from pinion center zpn. For Neither parallel nor intersecting it is automatically computed.
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For Line contact, enter Working width of pinion wpn.
In 2D, there are no settings for selecting the Contact Model. The Configuration is always Parallel and the Contact model is always set to the Point contact.
Gear Pair Properties
Define the advanced properties for a gear pair in this section.
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Select Include gear elasticity to enter the gear mesh stiffness, mesh damping, and the contact ratio. These properties can be entered in the Gear Elasticity subnode, which is added automatically. By default, this option is not selected.
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Select Include transmission error to enter the static transmission error for individual gears or for the gear pair. These can be entered in the Transmission Error subnode, which is added automatically. By default, this option is not selected.
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Select Include backlash to enter backlash in a gear pair. This can be entered in the Backlash subnode, which is added automatically. By default, this option is not selected.
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Select Include friction to add friction at the contact point. Enter frictional properties in the Friction (Gear) subnode, which is added automatically. By default, this option is not selected.
Contact Force Computation
Select an option from the list to use the method of computation for the forces at the contact point — Computed using weak constraints, or Computed using penalty method. Alternatively, you can also choose Do not compute.
For Computed using penalty method, enter Penalty factor pc. The default value is ((1[1/ms])^2)*mbd.grp1.me. The exact naming of the variable depends on the tags of the nodes in the model tree.
Theory for Gear Pairs
Location in User Interface
Context Menus
 Multibody Dynamics>Gear Pairs>Gear Pair
Ribbon
Physics tab with Multibody Dynamics selected:
Global>Gear Pairs>Gear Pair