What part of a gear tooth provides the profile between the top of the tooth and the bottom of the tooth space?

The dedendum is the section of a gear tooth that defines the depth of the tooth space or the distance from the pitch circle to the bottom of the tooth space. It essentially determines how far the tooth extends down into the gear, creating the space needed for adjacent teeth. This section is crucial as it ensures proper meshing of gears and influences the overall performance of the gear system.

When gears are designed, the relationship between the dedendum and addendum (the part of the tooth above the pitch circle) is significant for maintaining appropriate clearances and preventing interference during operation. The profile typically refers to the shape of the tooth itself, but it does not specifically address the area that connects the top of the tooth with the bottom of the tooth space. The throat is more a term used in context with the internal geometry of the gear, but it doesn’t cover the essential function carried out by the dedendum. Therefore, the dedendum is the correct term for describing the part of the gear tooth that delineates the profile between the top and the bottom of the tooth space.