Patent · US Expired

Marine counter-rotational propulsion system

US5890938A · kind A · utility

10Cited by
8References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 2, 1997
Grant dateApr 6, 1999
Priority date
Expiry dateOct 2, 2017

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF02B61/045
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

A marine propulsion system with counter-rotating propellers is provided with the capability of causing the propellers to rotate at different speeds. A first gear is attached to an inner propeller shaft and a second gear is attached to an outer propeller shaft. The inner and outer propeller shafts are arranged in coaxial and concentric relation for rotation about an axis of rotation. A driveshaft is connected to a pinion gear which engages the teeth of the fore and aft gears at different effective diameters. The pinion gear meshes with a first plurality of gear teeth on a beveled surface of the fore gear while a second set of gear teeth of the pinion gear mesh with a second plurality of gear teeth on a beveled surface of the aft gear. Because of the different effective diameters of the first and second pluralities of gear teeth, the inner and outer shafts rotate at different speeds.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.