Star worm gear
AssigneeWoodward, Inc.
InventorJoseph Thomas Kopecek
Life of this patent
Estimating the term…
Abstract
The subject matter of this specification can be embodied in, among other things, an actuator that includes a worm drive assembly having a worm shaft, and a worm wheel configured as a ring having a radially outer perimeter comprising a first collection of gear teeth extending radially outward from the radially outer perimeter and at least partly engaged with the worm shaft, and a coaxial radially inner perimeter comprising a second collection of gear teeth extending radially inward from the inner perimeter, and an epicyclic gear assembly having a sun gear and a planet gear engaged with the sun gear and the second collection of gear teeth.
Claims23
An actuator comprising:
- a housing;
- a back-drivable worm drive assembly comprising:
- a multiple start worm shaft configured to rotate about a first axis;
- and
- a worm wheel configured as a ring configured to rotate about a second axis that is substantially perpendicular to the first axis and having a radially outer perimeter comprising a first collection of gear teeth extending radially outward from the radially outer perimeter and at least partly engaged with the worm shaft, and a coaxial radially inner perimeter comprising a second collection of gear teeth extending radially inward from the coaxial radially inner perimeter;
- and
- an epicyclic gear assembly comprising:
- a grounded sun gear groundedly affixed to the housing;
- a planet gear carrier;
- and
- a planet gear carried by the planet gear carrier and engaged with the grounded sun gear and the second collection of gear teeth;
- a rotary-to-linear motion conversion assembly comprising a rotary assembly and a linear assembly;
- a rotary shaft engaged to the rotary assembly and the planet gear carrier;
- and
- a linear member engaged to the linear assembly and configured to move linearly.
A method of rotary-to-linear actuation comprising:
- rotating a multiple start worm shaft of a back-drivable worm drive assembly about a first axis;
- urging, by the multiple start worm shaft, rotation of a worm wheel of the back-drivable worm drive assembly about a second axis that is substantially perpendicular to the first axis, wherein the worm wheel is configured as a ring having a radially outer perimeter comprising a first collection of gear teeth extending radially outward from the radially outer perimeter and at least partly engaged with the worm shaft, and a radially inner perimeter comprising a second collection of gear teeth extending radially inward from the radially inner perimeter;
- urging, by the worm wheel, rotation of a planet gear, carried by a planet gear carrier, and engaged with the second collection of gear teeth about a grounded sun gear engaged with the planet gear, wherein the worm wheel, the planet gear, and the grounded sun gear are configured as an epicyclic gear assembly;
- urging, by the planet gear carrier, rotation of a rotary output member;
- urging, by the rotary output member, rotation of a rotary assembly of a rotary-to-linear motion conversion assembly;
- and
- urging, by the rotary-to-linear motion conversion assembly, linear movement of a linear assembly of the rotary-to-linear motion conversion assembly.
Dependencies are inferred from the claim text.