Gear Box (AB)

R2026b

Gear box mechanism in angle-based rotational systems

Since R2026b

• 

Gear Box (AB) block

To add a block to a model, double-click the canvas and start typing the block name. Then, select the block from the list.

Libraries:
Simscape / Foundation Library / Mechanisms

Description

The Gear Box (AB) block represents an ideal gear box with a fixed gear ratio. The gear ratio is the ratio of the angular velocity of the shaft at port B to the angular velocity of the shaft at port F. The gear ratio can be positive or negative.

The block uses the equations

$${\omega }_{\text{B}}=N\cdot {\omega }_{\text{F}}$$

$$t_{\text{B}}=\frac{1}{N}\cdot t_{\text{F}}$$

$${\theta }_{\text{Rel}}={\theta }_{\text{F}}-{\theta }_{\text{B}}$$

where:

• ω_B is the shaft angular velocity at port B.

• ω_F is the shaft angular velocity at port F.

• N is the gear ratio.

• t_B is the torque of the system acting on the shaft at port B.

• t_F is the torque of the shaft at port F acting on the system.

• θ_Rel is the relative angle between ports.

• θ_B and θ_F are the angles of ports B and F, respectively.

B and F are angle-based rotational conserving ports. For positive relative angle, port F has a more positive angle than port B.

Variables

To set the priority and initial target values for the block variables prior to simulation, use the Initial Targets section in the block dialog box or Property Inspector. For more information, see Set Priority and Initial Target for Block Variables.

Nominal values provide a way to specify the expected magnitude of a variable in a model. Using system scaling based on nominal values increases the simulation robustness. Nominal values can come from different sources, one of which is the Nominal Values section in the block dialog box or Property Inspector. For more information, see Modify Nominal Values for a Block Variable.

Ports

Conserving

B — Base port

angle-based rotational

Angle-based rotational conserving port that represents the base connection.

F — Follower port

angle-based rotational

Angle-based rotational conserving port that represents the follower connection.

Parameters

Gear ratio — Ratio of gear velocities

5 (default)

Ratio of the angular velocity of the shaft at port B to the angular velocity of the shaft at port F. You can specify positive or negative values.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2026b