Transmissions for outboard marine engines having internal ring gear and layshaft

A transmission for an outboard marine engine, the transmission comprising:

• a rotatable input shaft that is rotated by an internal combustion engine;
• a rotatable output shaft that powers a propulsor;
• a forward gear that causes forward rotation of the output shaft and propulsor;
• a reverse gear that causes reverse rotation of the output shaft and propulsor;
• a clutch that is movable between a forward clutch position wherein the forward gear causes the forward rotation of the output shaft and propulsor and a reverse clutch position wherein the reverse gear causes the reverse rotation of the output shaft and propulsor;
• an internal ring gear that couples the output shaft to the forward gear;
• wherein the internal ring gear comprises a sidewall having a radially inwardly facing engagement surface;
• wherein the forward gear comprises an outer engagement surface that engages with the radially inwardly facing engagement surface such that forward rotation of the forward gear causes forward rotation of the internal ring gear and the output shaft;
• and
• a layshaft having a first gear coupled to the reverse gear and a second gear coupled to the output shaft, wherein the layshaft transfers power from the input shaft to the output shaft only when the clutch is moved into the reverse clutch position.

A transmission for an outboard marine engine, the transmission comprising:

• a rotatable input shaft that is rotated by an internal combustion engine;
• a rotatable output shaft that powers a propulsor;
• a forward gear that causes forward rotation of the output shaft and propulsor;
• a reverse gear that causes reverse rotation of the output shaft and propulsor;
• a clutch that is movable between a forward clutch position wherein the forward gear causes the forward rotation of the output shaft and propulsor and a reverse clutch position wherein the reverse gear causes the reverse rotation of the output shaft and propulsor;
• an internal ring gear that couples the output shaft to the forward gear;
• wherein the internal ring gear comprises a sidewall having a radially inwardly facing engagement surface, and
• wherein the forward gear comprises an outer surface that engages with the radially inwardly facing engagement surface such that forward rotation of the forward gear causes forward rotation of the internal ring gear and the output shaft;
• and
• a layshaft having a first gear coupled to the reverse gear and a second gear coupled to the output shaft, wherein the layshaft transfers power from the input shaft to the output shaft only when the clutch is moved into the reverse clutch position;
• wherein the input shaft and output shaft are laterally offset from each other.