US 12,313,154 B2
Strain wave drive
Pawel Aleksander Chmielewski, Brzezia Laka (PL); Jonathan Darby, Newcastle (GB); Steve Davies, Shrewsbury (GB); Lukasz Turek, Wroclaw (PL); Marcin Cis, Wroclaw (PL); and Katarzyna Agata Łuszczyk, Wroclaw (PL)
Assigned to HAMILTON SUNDSTRAND CORPORATION, Charlotte, NC (US)
Filed by Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed on Dec. 14, 2023, as Appl. No. 18/540,212.
Claims priority of application No. 22461652 (EP), filed on Dec. 23, 2022.
Prior Publication US 2024/0209930 A1, Jun. 27, 2024
Int. Cl. F16H 49/00 (2006.01); B64C 13/34 (2006.01)
CPC F16H 49/001 (2013.01) [B64C 13/34 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A strain wave drive comprising:
an elliptical wave generator shaft rotatable about an axis (X);
a flexible tubular flex spline mounted around the wave generator shaft; and
a ring gear assembly mounted around the flex spline, the ring gear assembly comprising an output ring gear having a circular inner periphery and being sandwiched between two earth ring gears each having a circular inner periphery;
wherein the flex spline has a first number of radially outwardly extending teeth around its an outer periphery of the flex spline;
wherein each earth ring gear has the first number of radially inwardly extending teeth to engage with the teeth of the flex spline; and
wherein the output ring gear has a second number of radially inwardly extending teeth, wherein the second number is greater than the first number, such that as the wave generator shaft rotates, the rotation of the wave generator shaft causes the flex spline to take up the elliptical form of the wave generator shaft and the teeth of the flex spline engage with teeth of the output ring gear at the major diameter of the ellipse, causing the output ring gear to rotate; and
wherein the flex spline includes an engaging portion engaged with each earth ring gear and the output ring gear, and wherein only the engaging portion of the flex spline is deflected.