Marine pod drive system

Abstract

A marine pod drive system for a marine vessel is disclosed. The marine pod drive system may a prime mover, a transmission unit and a first drive shaft. The transmission unit may be driven by the prime mover via a first drive shaft. The transmission unit further rotates a first intermediate shaft. The marine pod drive system further may include an underwater steerable structure comprising a first gearbox, a second intermediate shaft, a second gearbox and a propeller shaft. The first gearbox may include a first helical gear mounted on the first intermediate shaft and a second helical gear mounted on the second intermediate shaft. The rotation or torque from the first intermediate shaft is transmitted to the propeller shaft via the first gearbox, the second intermediate shaft, and the second gearbox. The propeller shaft may drive at least one propeller to produce thrust to drive the marine vessel.

What is claimed is: 
     
         1 . A marine pod drive system for driving a marine vessel, comprising:
 a prime mover;   a transmission unit configured to be driven by the prime move via a first drive shaft;   a first intermediate shaft configured to be rotated by the transmission unit;   an underwater steerable structure, the underwater steerable structure comprising:
 a first gearbox, the first gearbox is driven by the first intermediate shaft, the first gearbox comprising:
 a first helical gear mounted on the first intermediate shaft; and 
 a second helical gear engaged with the first helical gear and configured to be rotated by the first helical gear; 
 
 a second intermediate shaft, wherein the torque from the first intermediate shaft is transmitted to the second intermediate shaft via the first gearbox; 
 a second gearbox configured to be rotated by the second intermediate shaft; 
 at least one propeller shaft configured to be driven by the second gearbox; and 
   at least one propeller configured to be rotated by the at least one propeller shaft.