US 12,331,811 B2
Gear arrangement
Estebane Geoffrey Joseph Champ-Locatelli Ép. Saltapes, La Balme (FR)
Appl. No. 18/853,676
Filed by CHAMP-LOCATELLI ÉP. SALTAPES, Estebane Geoffrey Joseph, La Balme (FR)
PCT Filed Apr. 7, 2023, PCT No. PCT/IB2023/000207
§ 371(c)(1), (2) Date Oct. 2, 2024,
PCT Pub. No. WO2023/194804, PCT Pub. Date Oct. 12, 2023.
Claims priority of application No. 2205215 (GB), filed on Apr. 8, 2022.
Prior Publication US 2025/0109781 A1, Apr. 3, 2025
Int. Cl. F16H 55/08 (2006.01); F16H 1/32 (2006.01); F16H 1/46 (2006.01)
CPC F16H 1/32 (2013.01) [F16H 1/46 (2013.01); F16H 55/0806 (2013.01); F16H 55/088 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A gearbox comprising an internal-external gear pair having a small tooth number difference, the internal-external gear pair comprising:
an internal gear, arranged about an internal gear axis and having a first number of internal gear teeth; and
an external gear having an external gear axis arranged to orbit the internal gear axis and having a second number of external gear teeth, the external gear being arranged to engage with the internal gear teeth;
wherein the small tooth number difference, between the second number of external gear teeth and the first number of internal gear teeth, is less than a fifth of the number of internal gear teeth;
wherein the internal gear teeth and the external gear teeth have an involute shape with no profile shift, or with a profile shift below a value at which respective working pressure angles of the external gear teeth and the internal gear teeth differ by more than 20% of the working pressure angle of the external gear teeth;
wherein at least one of the internal gear teeth and the external gear teeth has an addendum coefficient of less than 0.8; and
wherein at least one of the internal gear teeth and the external gear teeth have an addendum coefficient greater than 0.3.