Zahnradfabrik Friedrichshafen, Ag.

Zf-herion-systemtechnik Gmbh

Fritz Heinemann

George Marsland

Heinz Marschner

Strain-wave transmission with tubular strain wheel

One embodiment of a harmonic-drive device insertable, e.g., into a clutch housing having elevated fluid pressures comprises a cup-shaped member with a flexible cylindrical inserted in a casing and rigidly connected thereto, the cup member bearing at its end a pair of substantially cylindrical supports in which a drive shaft is rotatably journaled. The shaft bears a mechanical wave generator which deforms the middle portion of the cup wall into an elliptical cross-section, whereby splines on opposite sides of the cup wall are shifted to mesh with inwardly projecting teeth of a pair of rings, one ring having teeth greater in number than the splines and being attached to a motion-output component rotatably and slidably secured to the cup casing. The supports in the cup are tapered to a minimum diameter at their inner ends substantially equal to the minor axis of the elliptical cross-section. In another embodiment of the device, the wave generator and the supports are formed as an enlargement of the drive shaft provided on an outer surface with ribs or sealing stripes subdividing the surface of the enlargement into a matrix of compartments. The cross-section of the shaft enlargement varies from circular at the ends to elliptical in the center and the compartments are connected to a hydraulic circuit for being pressurized by a lubricating fluid.

Harmonic-drive assembly

One embodiment of a harmonic-drive device insertable, e.g., into a clutch housing having elevated fluid pressures comprises a cup-shaped member with a flexible cylindrical inserted in a casting and rigidly connected thereto, the cup member bearing at its end a pair of substantially cylindrical supports in which a drive shaft is rotatably journaled. The shaft bears a mechanical wave generator which deforms the middle portion of the cup wall into an elliptical cross-section, whereby splines on opposites sides of the cup wall are shifted to mesh with inwardly projecting teeth of a pair of rings, one ring having teeth greater in number than the splines and being attached to a motion-output component rotatably and slidably secured to the cup casing. The supports in the cup are tapered to a minimum diameter at their inner ends substantially equal to the minor axis of the elliptical cross-section. In another embodiment of the device, the wave generator and the supports are formed as an enlargement of the drive shaft provided on a outer surface with ribs or sealing stripes subdividing the surface of the enlargement into a matrix of compartments. The cross-section of the shaft enlargement varies from circular at the ends to elliptical in the center and the compartments are connected to a hydraulic circuit for being pressurized by a lubricating fluid.

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Friedrichshafen, Germany

Fritz Heinemann