MARINE PROPULSION SYSTEM SUPPORTED BY A STRUT
First Claim
1. A marine propulsion system, supported by a strut, comprising:
- an inner propeller shaft supporting a first propeller adjacent a trailing end thereof, and the inner propeller shaft having an interface, at a leading end thereof, to facilitate connection with a drive shaft for receiving torque supplied thereto and for supplying a first portion of the torque to the first propeller;
an outer propeller shaft supporting a second propeller adjacent a trailing and thereof, and the outer propeller shaft surrounding at least a portion of the inner propeller shaft; and
a differential gear set for receiving a second portion of the torque from the drive shaft and supplying the second portion of torque to the outer propeller shaft so that the second propeller rotates in an opposite direction to the first propeller;
wherein thrust, generated by rotation of the first and the second propellers, is conveyed back along either the inner propeller shaft or the outer propeller shaft and back to the drive shaft while the thrust, conveyed upstream to the drive shaft, avoids from passing through either the differential gear set or the strut.
1 Assignment
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Accused Products
Abstract
A marine propulsion system, supported by a strut, comprising an inner propeller shaft supporting a first propeller adjacent a trailing end thereof, and the inner propeller shaft is connected to the drive shaft for receiving and supplying a first portion of torque to the first propeller as well as transfer thrust, generated by the first propeller, along the inner propeller shaft back to the drive shaft. An outer propeller shaft supports a second propeller adjacent a trailing and thereof, and the outer propeller shaft surrounds the inner propeller shaft. A differential gear set receives a second portion of the torque and supplies the second portion to the outer propeller shaft so that the second propeller rotates in an opposite rotational direction to the first propeller. The thrust, generated by the first and the second propellers, is conveyed along either the inner or the outer propeller shafts, to the drive shaft.
3 Citations
20 Claims
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1. A marine propulsion system, supported by a strut, comprising:
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an inner propeller shaft supporting a first propeller adjacent a trailing end thereof, and the inner propeller shaft having an interface, at a leading end thereof, to facilitate connection with a drive shaft for receiving torque supplied thereto and for supplying a first portion of the torque to the first propeller; an outer propeller shaft supporting a second propeller adjacent a trailing and thereof, and the outer propeller shaft surrounding at least a portion of the inner propeller shaft; and a differential gear set for receiving a second portion of the torque from the drive shaft and supplying the second portion of torque to the outer propeller shaft so that the second propeller rotates in an opposite direction to the first propeller; wherein thrust, generated by rotation of the first and the second propellers, is conveyed back along either the inner propeller shaft or the outer propeller shaft and back to the drive shaft while the thrust, conveyed upstream to the drive shaft, avoids from passing through either the differential gear set or the strut. - View Dependent Claims (2)
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3. A marine propulsion system comprising:
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a strut having a strut through bore extending through; an inner propeller shaft supporting a first propeller adjacent a trailing end thereof, and the inner propeller shaft having an interface, at a leading end thereof, to facilitate connection with a drive shaft for receiving torque therefrom and supplying a first portion of the torque to the first propeller as well as for transferring thrust, generated by the first propeller, along the inner propeller shaft back to the drive shaft; an outer propeller shaft supporting a second propeller adjacent a trailing end thereof, and the outer propeller shaft surrounding a portion of the inner propeller shaft; the inner and the outer propeller shafts both extending through the strut through bore; a differential gear set being accommodated within the strut and surrounding both the outer and inner propeller shafts, the differential gear set comprising a differential input shaft, a differential output shaft and first and second idle gears, and the differential input shaft being drivingly connected to the inner propeller shaft in order to receive a second portion of the torque supplied thereto and the differential gear set reversing the second portion of the torque so that the differential output shaft drives the outer propeller shaft so as to rotate the second propeller in an opposite rotational direction than the first propeller; and a leading end of the outer propeller shaft being connected to a leading end of the inner propeller shaft to facilitate, during operation, both rotation of the outer propeller shaft with respect to the inner propeller shaft as well as transfer of thrust, generated by the second propeller, to the inner propeller shaft and back to the drive shaft. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of using a marine propulsion system to power a vessel, the method comprising:
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providing a strut having a strut through bore extending through; supporting a first propeller adjacent a trailing end of an inner propeller shaft, and forming an interface, adjacent a leading end of the inner propeller shaft, to facilitate connection with a drive shaft and receive torque therefrom, and the inner propeller shaft supplying a first portion of the torque to the first propeller as well as transferring thrust, generated by the first propeller, along the inner propeller shaft back to the drive shaft; supporting a second propeller adjacent a trailing end of an outer propeller shaft, and surrounding the inner propeller shaft with the outer propeller shaft; extending both the inner and the outer propeller shafts through the strut through bore; accommodating a differential gear set within the strut and at least partially surrounding the outer propeller shaft with the differential gear set, the differential gear set comprising a differential input shaft, a differential output shaft and a pair idle gears; drivingly connecting the differential input shaft to the inner propeller shaft in order to receive a second portion of the torque supplied thereto and drivingly connecting the differential output shaft to the outer propeller shaft with the differential gear set causing the second propeller to rotate in an opposite rotational direction than the first propeller; and connecting a leading end of the outer propeller shaft to a leading end of the inner propeller shaft to facilitate, during operation, both rotation of the outer propeller shaft with respect to the inner propeller shaft as well as transfer of thrust, generated by the second propeller, to the inner propeller shaft and back to the drive shaft.
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Specification