Ring type harmonic wave gear reducer

A ring-shaped harmonic gear speed reducer relates to a harmonic speed reducer aiming at solving the prior problems of low loading ability, low axiality of the dynamic and static rigid wheel and low driving accuracy.A wave producer(4) of the utility model is an elliptic cam, on the outer wall of which two flexible ball bearings(5) with the first guard ring(6) between them are provided, the axial direction of the two flexible ball bearings(5) are located respectively by an axial circlip (7) provided on the outer wall of the wave producer(4), a flexible wheel(3), engaged with a static rigid wheel(1)and a dynamic rigid wheel(2) having an axiality bearing(9)between them, is provided on the outer ring of the two flexible ball bearings(5), wherein the direction of axle of the axiality bearing(9) is located through the flange(1-1)on the outer wall of the static rigid wheel(1) and the second guard ring(8)on the outer wall of the static rigid wheel(1).The utility model can satisfy requiments of the high bearing ability in special driving situation, the high axiality between the dynamic and static rigid wheel, and the high driving accuracy.