A human powered watercraft or land vehicle is described herein. A watercraft or land vehicle may have two pedals that reciprocated are in a linear or slightly curved trajectory but not a circular motion. As the two pedals are reciprocated, an output shaft is rotated in either a clockwise or counterclockwise direction when the left pedal is pushed forward or when the right pedal is pushed forward. The output shaft may be connected to a propeller of a watercraft or a land vehicle so as to propel the watercraft or land vehicle forward. The output shaft may receive rotational input through two gears mounted to the output shaft with one-way bearings that enable the output shaft to rotate in the same direction regardless of whether the left pedal or the right pedal is being pushed forward.

A human powered watercraft or land vehicle is described herein. A watercraft or land vehicle may have two pedals that reciprocated are in a linear or slightly curved trajectory but not a circular motion. As the two pedals are reciprocated, an output shaft is rotated in either a clockwise or counterclockwise direction when the left pedal is pushed forward or when the right pedal is pushed forward. The output shaft may be connected to a propeller of a watercraft or a land vehicle so as to propel the watercraft or land vehicle forward. The output shaft may receive rotational input through two gears mounted to the output shaft with one-way bearings that enable the output shaft to rotate in the same direction regardless of whether the left pedal or the right pedal is being pushed forward.

A human powered watercraft or land vehicle is described herein. A watercraft or land vehicle may have two pedals that reciprocated are in a linear or slightly curved trajectory but not a circular motion. As the two pedals are reciprocated, an output shaft is rotated in either a clockwise or counterclockwise direction when the left pedal is pushed forward or when the right pedal is pushed forward. The output shaft may be connected to a propeller of a watercraft or a land vehicle so as to propel the watercraft or land vehicle forward. The output shaft may receive rotational input through two gears mounted to the output shaft with one-way bearings that enable the output shaft to rotate in the same direction regardless of whether the left pedal or the right pedal is being pushed forward.

A human powered watercraft or land vehicle is described herein. A watercraft or land vehicle may have two pedals that reciprocated are in a linear or slightly curved trajectory but not a circular motion. As the two pedals are reciprocated, an output shaft is rotated in either a clockwise or counterclockwise direction when the left pedal is pushed forward or when the right pedal is pushed forward. The output shaft may be connected to a propeller of a watercraft or a land vehicle so as to propel the watercraft or land vehicle forward. The output shaft may receive rotational input through two gears mounted to the output shaft with one-way bearings that enable the output shaft to rotate in the same direction regardless of whether the left pedal or the right pedal is being pushed forward.

A cycloidal marine propulsion unit, including a hollow rotary casing having a central axis and defining a central inner space with an opening at an axial end thereof. A mounting body rotatably supports the rotary casing on a hull of a marine vessel. A rotating arrangement is provided for rotating said hollow rotary casing, while a plurality of blades extend axially from the rotary casing away from the hull. Each blade is mounted for pivotal movement with respect to the rotary casing, about respective blade axes. The rotating arrangement is configured to rotate the rotary casing by a circumference thereof. A blade shaft portion of each blade is at least partly received within the central inner space so as to attach said blade to the rotary casing.

A cycloidal marine propulsion unit, including a hollow rotary casing having a central axis and defining a central inner space with an opening at an axial end thereof. A mounting body rotatably supports the rotary casing on a hull of a marine vessel. A rotating arrangement is provided for rotating said hollow rotary casing, while a plurality of blades extend axially from the rotary casing away from the hull. Each blade is mounted for pivotal movement with respect to the rotary casing, about respective blade axes. The rotating arrangement is configured to rotate the rotary casing by a circumference thereof. A blade shaft portion of each blade is at least partly received within the central inner space so as to attach said blade to the rotary casing.

A human powered watercraft or land vehicle is described herein. A watercraft or land vehicle may have two pedals that reciprocated are in a linear or slightly curved trajectory but not a circular motion. As the two pedals are reciprocated, an output shaft is rotated in either a clockwise or counterclockwise direction when the left pedal is pushed forward or when the right pedal is pushed forward. The output shaft may be connected to a propeller of a watercraft or a land vehicle so as to propel the watercraft or land vehicle forward. The output shaft may receive rotational input through two gears mounted to the output shaft with one-way bearings that enable the output shaft to rotate in the same direction regardless of whether the left pedal or the right pedal is being pushed forward.

A human powered watercraft or land vehicle is described herein. A watercraft or land vehicle may have two pedals that reciprocated are in a linear or slightly curved trajectory but not a circular motion. As the two pedals are reciprocated, an output shaft is rotated in either a clockwise or counterclockwise direction when the left pedal is pushed forward or when the right pedal is pushed forward. The output shaft may be connected to a propeller of a watercraft or a land vehicle so as to propel the watercraft or land vehicle forward. The output shaft may receive rotational input through two gears mounted to the output shaft with one-way bearings that enable the output shaft to rotate in the same direction regardless of whether the left pedal or the right pedal is being pushed forward.

A propeller drive assembly includes a driveshaft for transferring a torque between an engine and a propeller of a water surface vessel, and a housing enclosing the driveshaft. The assembly includes, separately from the driveshaft, a first element and a second element, the first element extending through a first bore of the second element, wherein one of the first and second elements is fixed to the driveshaft and the other of the first and second elements is arranged to be stationary in relation to the housing, and the one of the first and second elements which is fixed to the driveshaft presents in the first bore a first elongated cavity forming a first helix along the first bore, so as to form with the other of the first and second elements a screw pump.

A propeller drive assembly includes a driveshaft for transferring a torque between an engine and a propeller of a water surface vessel, and a housing enclosing the driveshaft. The assembly includes, separately from the driveshaft, a first element and a second element, the first element extending through a first bore of the second element, wherein one of the first and second elements is fixed to the driveshaft and the other of the first and second elements is arranged to be stationary in relation to the housing, and the one of the first and second elements which is fixed to the driveshaft presents in the first bore a first elongated cavity forming a first helix along the first bore, so as to form with the other of the first and second elements a screw pump.