US 12,215,770 B1
Strain wave gear differential with high gear reduction
Derick S. Balsiger, Prescott Valley, AZ (US); and Keith A. Bloxham, Gilbert, AZ (US)
Assigned to HAMILTON SUNDSTRAND CORPORATION, Charlotte, NC (US)
Filed by Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed on Dec. 20, 2023, as Appl. No. 18/390,332.
Int. Cl. F16H 49/00 (2006.01); F16H 35/00 (2006.01)
CPC F16H 49/001 (2013.01) [F16H 35/008 (2013.01); F16H 2049/003 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A harmonic drive, comprising:
a ground ring;
a first flex spline extending axially from the ground ring;
a first input shaft that is radially exterior to the first flex spline,
wherein the first input shaft includes a first wave generator that engages the first flex spline;
a second flex spline, radially within the first flex spline and rotationally coupled to the first flex spline,
a second input shaft that is radially within the second flex spline,
wherein the second input shaft includes a second wave generator that engages the second flex spline;
an output shaft coupled to the second flex spline,
wherein:
the first flex spline includes a first spline that faces radially inward;
the second flex spline includes a second spline that faces radially outward; and
the drive further includes a circular gear that includes: a third spline that face outwardly and engages the first spline; and a fourth spline that faces radially inward and engages the second spline.