For the option | Do the following |
|---|---|
Material (Gear1/Gear2) | |
Define Mass By | ■User Input If you do not want Adams View to calculate mass and inertia using a part's geometry, material type, or density, you can enter your own mass and moments of inertia. ■Geometry and Density You can change the material type used to calculate mass and inertia or simply specify the density of the part. ■Geometry and Material Type The geometry defines the volume and the material type defines the density. |
If you select User Input, the following options will be displayed: | |
Mass | Enter the mass of the gear part. |
The parts are located at the center of the gear, with the z-axis as the rotational axis. | |
Inertia | |
Ixx/Iyy/Izz | Enter the values that define the principal mass-inertia components of the gear part. |
Ixy/Izx/Iyz | Enter the values that define the deviational (cross-product) mass-inertia components of the gear part. |
If you select Geometry and Density, the following options will be displayed: | |
Density | Enter the density value. |
Inertia Geometry | ■ Exact Define mass by default 'density' option, Adams View uses the part's density and the volume of the geometry to calculate its mass and inertia. ■Approximate Approximate volume of the gear element is calculated based on addition of gear blank (cylinder or cone) dimension and involute thread volume. Bore volume is subtracted from this calculated volume. For cylindrical gears, the cylindrical gear blank dimension is considered whereas front and rear cone dimensions are considered in case of bevel and hypoid. Rack considers the base width and trapezoidal teeth volume. The approximately calculated volume is multiplied by density to calculate mass. Approximate method has significant gain in performance over material and exact-density options. However, the calculated values are slightly less than other methods. |
If you select Geometry and Material Type, the following options will be displayed: | |
Material Type | Enter the material type to be used inertia calculation. |
Contact Settings | |
Stiffness | ■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 (<top_dir>\amachinery\examples\gear_stiffness_prop.gfs). |
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. |
Backlash | Select if the Backlash should be entered as an Angle or as a Length. ■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. ■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. |
Sharpness factor | Sharpness factor of the backlash. Controls how sharp the transition is between the lash region with zero forces and the stiff region. See Simplified Gear Method for more information. |
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. See Simplified Gear Method for more information. |
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: ■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) The additional coupling effects are only valid for smaller deflections and angles. Note: This is currently available only for Spur/Helical. |
Carrier Part | Specify a part on which reference marker for the simplified gear force (adams general force) is created. By default it is ground. A marker created on this part serves as coordinate reference for the definition of three orthogonal force components of the simplified gear force. |