Gear constraint between two frames spinning about parallel axes
This block represents a common gear constraint between two frames. This constraint restricts motion such that rotation of the base frame causes rotation of the follower frame and vice-versa. Base and follower frames represent two meshed gears rotating about parallel Z axes. The structure of the model must be such that the Z axes of the two frames are parallel for all time.
The common gear constraint can be external, in which case the two frames rotate in opposite directions, or internal, in which case the two frames rotate in the same direction. For the two frames to rotate jointly, they must possess two rotational degrees of freedom about parallel axes. In a model, joint blocks provide these degrees of freedom˙.
The block dialog box contains a Properties area with common gear options and parameters.
Select gear type. Options include internal or external. Internal gears have teeth along the inner circumference. External gears have teeth along the outer circumference. The default type is External.
Select the method to specify the common gear with. Options include Center Distance and Ratio and Pitch Circle Radii.
Specify the common gear constraint in terms of the center-to-center separation distance and the gear teeth ratio (Nf/Nb).
Enter the center-to-center distance between base and follower gears. Select a physical unit. The default value is 20.0 cm.
Enter the gear teeth ratio between base and follower gears. This ratio is Nf/Nb, where Nf and Nb represent the number of teeth in the follower and base gears, respectively. The default value is 1.0.
Specify the common gear in terms of the base and follower gear radii.