Harmonic gear drives are widely used in space mechanism in nearly decades

but the solid lubrications of the reducer is a difficult problem until now. In this paper

the authors studied vacuum running behaviors of XB 3 60 harmonic reducer under solid lubrication by a self made vacuum running tester. The test results showed that this tester is reasonable and reliable for harmonic reducer

and the PVD film has a good luibricating properties for space mechanism.