abstract:The harmonic coordinate condition is one of several coordinate conditions in general relativity, which make it possible to solve the Einstein field equations. A coordinate system is said to satisfy the harmonic coordinate condition if each of the coordinate functions xα (regarded as scalar fields) satisfies d'Alembert's equation.
The coordinateequationandnoninterferentialconditionof tooth profiles are used to calculate interferenceof tooth profiles of the single wave harmonicdrive.