For the option: | Do the following: |
|---|---|
Gear Force Name | Enter the name of the simplified gear force element. |
Gear 1 | Enter the name for Gear 1. |
Gear 2 | Enter the name for Gear 2. |
Property File | You can reference to available property file to specify input parameters for gear and force. |
Stiffness Model | ■Constant Enter a value for the stiffness coefficient of the gear-to-gear contact. ■Spline Select a gear stiffness property file (*.gfs) which contain tabular gear-to-gear contact stiffness values as function on a normalized gear pitch values (ideally from 0 to 1). However, to ensure continuous transitions between the gear stiffness values when going from one pitch to another, the gear pitch values should be specified between 0 and 2. The gear stiffness values should be repeated for the gear pitch values between 1 and 2. See an example of gear stiffness property file. |
If you selected stiffness model as “Constant” the following option displayed: | |
Contact Stiffness | Enter a value for the stiffness coefficient of the gear-to-gear contact. Note: The stiffness coefficient should always be the translational stiffness, that is, with units Force/Length. To get a full description of all contact parameters please refer to the online help for the IMPACT function. |
If you selected stiffness model as “Spline” the following option displayed: | |
Property File | You can reference to available property file to specify input parameters for gear and force. |
Coupling Directions | Determines which degree of freedom of the relative deflections of gear and wheel which will be taken into account when calculating the single point contact force between them. As default and minimum the rotational (spin) direction is always considered. But for instance if the axial stiffness of the helical gear and/or wheel axle mounting is relatively weak, it will also affect the kinematics of the gear and wheel movements when the torque is developed between them. The generated axial force will try to axially separate the gear and wheel and while they move in this direction they will also rotate like a screw relative to each other. Hence, the measurable torsional (rotating) stiffness between gear and wheel will be decreased due to this effect. The user can additional select a total of four other couplings directions to measure and taken into account in gear force calculation: ■Rotational: ■Radial: Relative radial deflection of the gear and wheel (axle center distance) ■Axial: Relative axial deflection of the gear and wheel (z translational direction) ■Tangential: Relative tangential deflection of gear and wheel ■Tilting: Relative tilting angle between gear and wheel (out of plane) |
All on/off | Click to select/deselect all the coupling dirctions options. |
Damping Ratio | Enter a value for the damping ratio of the gear-to-gear contact. The resulting damping in the gear-to-gear contact will be: Contact Damping = Damping Ratio * Contact Stiffness The contact damping is always expressed be the translational damping, that is, with units Force-Time/Length, regardless if the backlash is measured as an angle or a length. The damping will be converted to appropriate units in the machinery solver code. |
Sharpness Factor | Sharpness factor of the backlash. Controls how sharp the transition is between the lash region with zero forces and the stiff region. |
Backlash Type | Select if the Backlash should be entered as an Angle or as a Length. |
Backlash Angle | Enter a value for the backlash between the gears. The backlash is the total angle, that is, one tooth of Gear 1 is able to move half the backlash angle in either direction before contact with a tooth at Gear 2. |
Backlash Length | Enter a value for the backlash between the gears. The backlash is the total length, that is, one tooth of Gear 1 is able to move half the backlash length in either direction before contact with a tooth at Gear 2. The backlash length is at the Gear 1 base circle. |
Backlash Smoothing Time | Time for ramping up back lash value from zero to its entered value. This smoothing functionality can be useful in order to reduce initial transients in the simulations. Setting value to zero deactivate the smoothing functionality. |