High torque density miniature laminar gear transmission

Inventors

Weir, Richard • Huddle, Stephen • Murali, Barathwaj • Celik, Ozkan

Assignees

Colorado School of Mines • University of Colorado Colorado Springs

Abstract

A miniturized laminar gear box possessing high torque densities and methods of manufacturing the same. The high torque density is possible by directing the output shaft of the planetary stages through the sun gear and behind the input shaft. This allows the input shafts of the planetary stages to face towards the interior of the gearbox and provides a rotary shaft for the spur stages housed in between the planetary stages.

Core Innovation

The invention provides a compact, high torque density gearbox that uses stacked lamina to integrate gear stages. A first lamina includes a first planetary gear stage having an output cage, and the output cage includes an output shaft extending perpendicular from the planetary stage and crossing from the first lamina to a second lamina.

In the second lamina, a second planetary gear stage is provided with a sun gear and at least two planet gears. The output shaft of the first planetary stage interfaces with the sun gear of the second planetary stage, forming a stacked planetary-to-planetary arrangement that enables torque transmission across adjacent lamina.

The described embodiments also include additional internal gearing using a rotary shaft arrangement for spur stages. A first pinion gear positioned between stages uses the output shaft as its rotary shaft, and at least two planet gears interface with the first pinion gear. Further embodiments include a third planetary stage in the second lamina and a spur gear where the pinion gear interfaces with the spur gear and the spur gear’s input shaft interfaces with the sun gear of the third planetary stage. The disclosed gearbox possesses a torque density of at least 0.15 Nm/m3.

Claims Coverage

The independent claim defines a compact, high torque density gearbox with stacked lamina and inter-lamina torque transfer, and it specifies 5 inventive features. Dependent claims refine the architecture by adding pinion and further stage-to-spur stage interfaces while maintaining the torque density requirement.

Overall, the claims cover a compact gearbox built from stacked lamina with a first planetary output cage that sends an output shaft perpendicular across lamina to interface with a sun gear in a second planetary stage. The claim set further tightens the torque transfer path using a pinion gear with an assigned rotary output shaft, specifies that planet gears interface with that pinion, and optionally extends the stack with a third planetary stage and a spur gear interface. The gearbox is defined to achieve a torque density of at least 0.15 Nm/m3.

Stated Advantages

Documented Applications