modelLossyPlanetary
Lossy planetary gear box
Information
The LossyPlanetary gear box is derived from the IdealPlanetary gear box from the standard Modelica Library.
It is made up of an inner sun wheel, an outer ring wheel and a
planet wheel located between sun and ring wheel. The bearing
of the planet wheel shaft is fixed in the planet carrier. The component can be connected to other elements at the
sun, ring and/or flanges. It is not possible to connect
to the planet wheel. Inertia is considered by attaching an inertia block to the planetary gear.
The kinematic equations involving all three gears can be described as follows:
N_sun/N_ring = (w_planet - w_ring)/(w_sun - w_planet)
with ratio=N_ring/N_sun, the equation above can be simplified to
(1+ratio)*w_planet = w_sun + ratio*w_ring
Generally, the teeth of the gears are related as follows (assuming number of teeth is proportional to diameter):
N_sun + 2*N_planet = N_ring
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | ratio | 14.4 | number of ring_teeth/sun_teeth (e.g. ratio=100/50) |
| Real | eta | 0.78 | efficiency of gearhead |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Mechanics.Rotational.Interfaces.Flange_a | sun | Flange of sun shaft | |
| Modelica.Mechanics.Rotational.Interfaces.Flange_a | planet | Flange of carrier shaft | |
| Modelica.Mechanics.Rotational.Interfaces.Flange_b | ring | Flange of ring shaft |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.SIunits.AngularVelocity | w | ||
| Modelica.SIunits.AngularAcceleration | a |