| 摘要 |
1,228,986. Variable ratio friction gears. S. STAUBER. 11 July, 1968 [13 July, 1967], No. 33158/68. Heading F2D. A steplessly variable ratio friction gear of the "harmonic" or "strain wave" type comprises a radially deformable ring 1 pressed by planet wheels 2 into frictional engagement with a coaxial interfitting ring 10 at a number of peripheral locations, the rings engaging at surfaces 7, 11 which are of frusto-conical or other form giving axial variation of diameter, and one ring being axially adjustable relative to the other to vary the gear ratio. Either of the rings 1, 10 may be the output member, the other being held stationary. The planet wheels 2 engage an input sun wheel 3 on a shaft 4. Wheels 2, 3 and the inner surface of ring 1 may have frictional or toothed engagement. The adjustable ring may be moved manually or by any suitable power means. In a modification, the sun and planet wheels are replaced by a polygonal member on the shaft 4, the apices of the polygon being in sliding contact with the ring 1. In a further modification, the planet wheels 2 or the polygonal member are external of the outer ring 10, which is the deformable ring in this case. |
