This tutorial shows how to assemble gears (that are imported) in SpaceClaim. The type of gears considered is “External Gears”. These are typically used to increase or decrease the speed of shafts. Usually, one of the gears has lesser number of teeth (higher RPM/Speed) and the other has larger number of teeth (lower RPM).
When gears are imported inside SpaceClaim, we need to define Gear Condition/Constraint between them, which is done by selecting two cylindrical surfaces. The main task boils down to finding out the radii of these mating cylinders (also known as Pitch Radius). The following diagram shows the equations of determining the radii R1 and R2 of the two cylinders, given the number of teeth in the gears and the distance between the centers of the gears. We have two equations with R1 and R2 and solving for R1 and R2 is straight forward.
- We have imported a Gear Assembly from GrabCAD.
- The revolute joints (consisting of a Align condition + Tangent condition) are defined so that gears have a freedom to rotation (degree-of-freedom) about their axes.
- The pitch cylinders are determined in the form of surfaces (which do not add up to the mass of the components)
- Gear condition is defined between them.
- One of the gears is rotated and the other rotates due to meshing.
- Go to SC-Motion. Gear conditions are made use of in the solver and simulation is done.
The SpaceClaim assembly file (with Gear condition defined) can be downloaded here.