Geared motor

Introduced in MORe v4.2

Represents a geared motor. Models rotor and gear inertia including gear reduction.

Block diagram

Signal	Description
\(u_f\)	Filter output
\(u_v\)	Coupling link velocity
\(u_x\)	Coupling link position
\(v_{fb}\)	Motor velocity. Can be used as feedback in architecture.
\(x_{fb}\)	Motor position. Can be used as feedback in architecture.
\(y\)	Motor output. Force acting on coupling link.

Parameter

Variable	Units linear	Units rotary	Description
Gear ratio	\(-\)	\(-\)	Gear ratio
Stiffness	\(N/m\)	\(Nm/rad\)	Stiffness of gear at the output shaft [1]
Damping	\(N s/m\)	\(Nm s/rad\)	Damping of gear
Inertia	\(kg\)	\(kg m^2\)	Gear and motor inertia [2]
Spindle pitch	\(-\)	\(m\)	Ballscrew spindle pitch. [3]

[1]

Torsional stiffness, usually referred as \(C_{t21}\) in datasheets. Calculated as quotient of applied to torque to the output shaft and its resulting twist. (The input shaft is fixed) \(C_{t21} = \Delta T / \Delta\phi\)

[2]

Total inertia as sum of rotor inertia and gear inertia observed from the drive side.

[3]

Used in postprocessor to allow for scaling of the error only. Scales setpoints to linear axis movement.

\(x_{lin} = x_{rot} \frac{hs}{2 \pi \cdot gr}\)

Coupling

Link selection to represent the motor. The controller output (force/torque) will be applied to the selected link.