The Lossy Gear component models the gear ratio and the losses of a standard gear box in a realistic way, including the stuck phases that may occur at zero speed. The gear boxes that can be handled are fixed in the ground or on a moving support, have one input and one output shaft, and are essentially described by the equations
where is constant gear ratio, is the efficiency due to mesh friction, and is the bearing friction torque.
Loss Table
The Loss Table parameter is five-column table that defines the loss terms and in terms of the absolute value of the input shaft speed, , and of the energy flow direction. Its columns are with
|
|
Angular speed of
|
|
|
Mesh efficiency when input shaft is driving
|
|
|
Mesh efficiency when output shaft is driving
|
|
|
Absolute bearing friction torque when input shaft is driving
|
|
|
Absolute bearing friction torque when output shaft is driving
|
|
|
The rows of the Loss Table are ordered according to , with the first row having the smallest . The values for , , , and at a particular shaft speed are interpolated from the values in the table.
To add rows to the table, right-click on the value and select Edit Matrix Dimension.
With these variables, the mesh efficiency and the bearing friction are formally defined as
Losses are modeled in a physically meaningful way taking into account that at zero speed the movement may be locked due to the friction in the gear teeth and/or in the bearings.