Transmission for driving counter-rotating propellers, lubrication system, and associated methods

A transmission for converting an engine drive shaft rotation into coaxial counter-rotations for driving a pair of propellers, the transmission comprising:

• a fore driven gear having teeth, the fore driven gear affixable to an inner shaft for rotating an outer propeller;
• a driven sprocket having teeth affixable to a hollow outer shaft coaxial with the inner shaft for rotating an inner propeller, the driven sprocket coaxial with the fore driven gear;
• a drive shaft having an aft end rotatably affixable within the housing and a fore end having means for being rotatably driven;
• a fore gear affixed for corotation with the drive shaft and having fore gear teeth positioned for meshing with the fore driven gear teeth for driving the fore driven gear in a first direction;
• a drive sprocket affixed for corotation with the drive shaft and having for driving the driven sprocket in a second direction opposite the first direction;
• and
• a chain meshable with the teeth of the driven sprocket and the drive sprocket.

A method for improving an efficiency and lowering a noise output of a counter-rotating-propeller-driven vehicle comprising the steps of:

• providing a propulsion system comprising:
• an inner shaft having means for affixing an outer propeller thereto;
• a hollow outer shaft having a lumen therethrough and means for affixing an inner propeller thereto and positionable in surrounding and coaxial relation to the inner shaft;
• a fore driven gear having teeth, the fore driven gear affixable to the inner shaft;
• a driven sprocket having teeth affixable to the outer shaft, the driven sprocket coaxial with the fore driven gear;
• a drive shaft having an aft end rotatably affixable within the housing and a fore end having means for being rotatably driven;
• a fore gear affixed for corotation with the drive shaft and having fore gear teeth positioned for meshing with the fore driven gear teeth for driving the fore driven gear in a first direction;
• a drive sprocket affixed for corotation with the drive shaft and having teeth for driving the driven sprocket in a second direction opposite the first direction;
• a chain meshable with the teeth of the driven sprocket and the drive sprocket;
• and
• utilizing the propulsion system to drive a pair of propellers in counter-rotating motion.

A propulsion system for driving a pair of propellers in counter-rotation, the transmission comprising:

• an inner shaft having means for affixing an outer propeller thereto;
• a hollow outer shaft having a lumen therethrough and means for affixing an inner propeller thereto and positionable in surrounding and coaxial relation to the inner shaft;
• a fore driven gear having teeth, the fore driven gear affixable to the inner shaft;
• a driven sprocket having teeth affixable to the outer shaft, the driven sprocket coaxial with the fore driven gear;
• a drive shaft having an aft end rotatably affixable within the housing and a fore end having means for being rotatably driven;
• a fore gear affixed for corotation with the drive shaft and having fore gear teeth positioned for meshing with the fore driven gear teeth for driving the fore driven gear in a first direction;
• and
• a drive sprocket affixed for corotation with the drive shaft and having teeth for driving the driven sprocket in a second direction opposite the first direction;
• and
• a chain meshable with the teeth of the driven sprocket and the drive sprocket.

A transmission for converting an engine drive shaft rotation into coaxial counter-rotations for driving a pair of propellers, the transmission comprising:

• a housing having an interior space, a fore side, and an aft side opposed to the fore side, the fore side affixable to an engine bell housing, an opening in the aft side for permitting a pair of coaxial propeller shafts to pass therethrough, and an opening in the fore side;
• a fore driven gear having teeth, the fore driven gear positioned within the housing interior space and affixable to an inner shaft for rotating an outer propeller;
• a driven sprocket having teeth positioned within the housing interior space and affixable to a hollow outer shaft coaxial with the inner shaft for rotating an inner propeller, the driven sprocket coaxial with the fore driven gear;
• a drive shaft having an aft end rotatably affixable within the housing and a fore end extending through the housing fore side opening and having means for being rotatably driven by an engine;
• a fore gear affixed for corotation with the drive shaft and having fore gear teeth positioned for meshing with the fore driven gear teeth for driving the fore driven gear in a first direction;
• a drive sprocket affixed for corotation with the drive shaft and having teeth for driving the driven sprocket in a second direction opposite the first direction;
• and
• a chain meshable with the teeth of the driven sprocket and the drive sprocket.

A propulsion and lubrication system comprising:

• a hollow inner shaft for rotating an outer propeller having an opening at an end thereof and a lumen therethrough in communication with the hole;
• a hollow outer shaft coaxial with the inner shaft for rotating an inner propeller positioned in surrounding and coaxial relation to the inner shaft;
• removable means for sealing the opening in the inner shaft;
• means for driving the inner and outer shaft in counter-rotating relation;
• and
• bearing means positionable between the inner and the outer shafts in covering relation to the hole, the bearing means movable relative to the inner shaft;
• wherein lubricant is sealable within the inner shaft and is distributable through the hole, between the inner shaft and the bearing means, into a space between the inner and the outer shaft, without a pump for circulating the lubricant.

A method for making a transmission comprising the steps of:

• rotatably affixing a fore driven gear having teeth within a housing and to an inner shaft for rotating an outer propeller;
• rotatably affixing a driven sprocket having teeth within the housing and to a hollow outer shaft coaxial with the inner shaft for rotating an inner propeller, the driven sprocket coaxial with the fore driven gear;
• opposedly affixing a fore end and an aft end of a drive shaft for rotation within the housing;
• mounting a fore drive gear on the drive shaft in driving relation to the fore driven gear;
• mounting a drive sprocket on the drive shaft in driving relation to the driven sprocket;
• meshing a chain with the teeth of the driven sprocket and the drive sprocket;
• and
• providing means for driving the fore driven gear and the driven sprocket in counter-rotation.

A transmission for converting an engine drive shaft rotation into coaxial counter-rotations for driving a pair of propellers, the transmission comprising:

• a driven sprocket having teeth affixable to an inner shaft for rotating an outer propeller;
• an aft driven gear having teeth, the aft driven gear affixable to a hollow outer shaft coaxial with the inner shaft for rotating an inner propeller, the aft driven gear coaxial with the driven sprocket;
• a drive shaft having an aft end rotatably affixable within the housing and a fore end having means for being rotatably driven;
• a drive sprocket affixed for corotation with the drive shaft and having teeth for driving the driven sprocket in a first direction;
• an aft drive gear affixed for corotation with the drive shaft and having aft gear teeth positioned for meshing with the aft driven gear teeth, the aft gear teeth for driving the aft driven gear in a second direction opposite the first direction;
• and
• a chain meshable with the teeth of the driven sprocket and the drive sprocket.

A propulsion system for driving a pair of propellers in counter-rotation, the transmission comprising:

• an inner shaft having means for affixing an outer propeller thereto;
• a hollow outer shaft having a lumen therethrough and means for affixing an inner propeller thereto and positionable in surrounding and coaxial relation to the inner shaft;
• a driven sprocket having teeth affixable to the inner shaft;
• an aft driven gear having teeth, the aft driven gear affixable to the outer shaft, the aft driven gear coaxial with the driven sprocket;
• a drive shaft having an aft end rotatably affixable within the housing and a fore end having means for being rotatably driven;
• a drive sprocket affixed for corotation with the drive shaft and having teeth for driving the driven sprocket in a first direction;
• and
• an aft gear affixed for corotation with the drive shaft and having aft gear teeth positioned for meshing with the aft driven gear teeth for driving the aft driven gear in a second direction opposite the first direction;
• and
• a chain meshable with the teeth of the driven sprocket and the drive sprocket.

A transmission for converting an engine drive shaft rotation into coaxial counter-rotations for driving a pair of propellers, the transmission comprising:

• a housing having an interior space, a fore side, and an aft side opposed to the fore side, the fore side affixable to an engine bell housing, an opening in the aft side for permitting a pair of coaxial propeller shafts to pass therethrough, and an opening in the fore side;
• a driven sprocket having teeth positioned within the housing interior space and affixable to an inner shaft for rotating an outer propeller;
• an aft driven gear having teeth, the aft driven gear positioned within the housing interior space and affixable to a hollow outer shaft coaxial with the inner shaft for rotating an inner propeller, the aft driven gear coaxial with the driven sprocket;
• a drive shaft having an aft end rotatably affixable within the housing and a fore end extending through the housing fore side opening and having means for being rotatably driven by an engine;
• a drive sprocket affixed for corotation with the drive shaft and having teeth for driving the driven sprocket in a first direction;
• an aft drive gear affixed for corotation with the drive shaft and having aft gear teeth positioned for meshing with the aft driven gear teeth for driving the aft driven gear in a second direction opposite the first direction;
• and
• a chain meshable with the teeth of the driven sprocket and the drive sprocket.

A method for improving an efficiency and lowering a noise output of a counter-rotating-propeller-driven vehicle comprising the steps of:

• providing a propulsion system comprising:
• an inner shaft having means for affixing an outer propeller thereto;
• a hollow outer shaft having a lumen therethrough and means for affixing an inner propeller thereto and positionable in surrounding and coaxial relation to the inner shaft;
• a driven sprocket having teeth affixable to the inner shaft;
• an aft driven gear having teeth, the aft driven gear affixable to the outer shaft, the aft driven gear coaxial with the driven sprocket;
• a drive shaft having an aft end rotatably affixable within the housing and a fore end having means for being rotatably driven;
• a drive sprocket affixed for corotation with the drive shaft and having teeth for driving the driven sprocket in a first direction;
• an aft gear affixed for corotation with the drive shaft and having aft gear teeth positioned for meshing with the aft driven gear teeth for driving the aft driven gear in a second direction opposite the first direction;
• and
• a chain meshable with the teeth of the driven sprocket and the drive sprocket;
• and
• utilizing the propulsion system to drive a pair of propellers in counter-rotating motion.