Granted Patent B2

US 12,655,896 · App. 18/584,384 · Granted Jun 16, 2026

Inventors: Łukasz Turek (Wrocław, PL); Jonathan A. Darby (Newcastle, GB); Paweł Chmielewski (Brzezia Łąka, PL); Marcin Cis (Lutynia, PL)

Assignee: HAMILTON SUNDSTRAND CORPORATION

F16H49/001B64C13/28F16H2049/003

Abstract

Claims (41)

1 . A flex spline for a strain wave drive, the flex spline comprising:

a flexible tubular body having a first open end and a second open end;

a first set of radially outwardly extending teeth around its outer periphery at the first open end;

a second set of radially outwardly extending teeth around its outer periphery at the second open end; and

a third set of teeth located axially between the first and the second sets of teeth, wherein the teeth extend outwardly;

wherein the flexible tubular body further comprises:

one or more sections of changed geometry located between the first and third sets of teeth or the second and third sets of teeth,

wherein the sections of changed geometry are provided with a geometric feature in the flex spline body that is not present in the remainder of the flex spline body;

wherein the geometric feature comprises a plurality of perforations;

wherein the perforations are not shaped as a circle in cross-section.

2 . The flex spline of claim 1 , wherein the perforations are elliptical in cross-section.

3 . A strain wave drive comprising:

a flex spline according to claim 1 .

4 . The strain wave drive of claim 3 for moving a flight control surface of an aircraft.

5 . A flex spline for a strain wave drive, the flex spline comprising:

a flexible tubular body having a first open end and a second open end;

a first set of radially outwardly extending teeth around its outer periphery at the first open end;

a second set of radially outwardly extending teeth around its outer periphery at the second open end; and

a third set of teeth located axially between the first and the second sets of teeth, wherein the teeth extend outwardly;

wherein the flexible tubular body further comprises:

one or more sections of changed geometry located between the first and third sets of teeth or the second and third sets of teeth,

wherein the sections of changed geometry are provided with a geometric feature in the flex spline body that is not present in the remainder of the flex spline body;

wherein the geometric feature comprises a portion of reduced thickness;

wherein a radially inner undercut creates the portion of reduce thickness.

6 . The flex spline of claim 5 , wherein the portion of reduced thickness has a varying thickness across the section.

7 . A strain wave drive comprising:

a flex spline according to claim 5 .

8 . The strain wave drive of claim 7 for moving a flight control surface of an aircraft.

9 . A flex spline for a strain wave drive, the flex spline comprising:

a flexible tubular body having a first open end and a second open end;

a first set of radially outwardly extending teeth around its outer periphery at the first open end;

a second set of radially outwardly extending teeth around its outer periphery at the second open end; and

a third set of teeth located axially between the first and the second sets of teeth, wherein the teeth extend outwardly;

wherein the flexible tubular body further comprises:

one or more sections of changed geometry located between the first and third sets of teeth or the second and third sets of teeth,

wherein the sections of changed geometry are provided with a geometric feature in the flex spline body that is not present in the remainder of the flex spline body;

wherein the geometric feature comprises corrugations formed in the body.

10 . The flex spline of claim 9 , wherein the section of changed geometry includes a corrugated portion and a portion of reduced thickness.

11 . A strain wave drive comprising:

a flex spline according to claim 10 .

12 . The strain wave drive of claim 11 for moving a flight control surface of an aircraft.

Assignments (2)

Priority Claims (1)

Continuity (1)

References Cited (15)