Diver-propulsion units

Abstract

A diver-propulsion unit 1 has a two-part cylindrical casing 2,3 with hand-grips 9 either side for holding forwardly of the swimming diver and giving maneuverability. Propulsion-thrust is from a propeller 15 rotating within a cylindrical duct 14 of a nozzle-mount 11 to which the casing-parts 2,3 are clamped. The propeller 15 is driven via a belt-drive 25,26 by an electric motor 22 which is mounted on the nozzle-mount 11 outside the duct 14 and which is powered by batteries in externally-projecting pods 31 of the rear casing-part 3 . The belt-drive 25,26 extends across the water-flow to the duct 14 within a channel 29 of the nozzle-mount 11 . The channel 29 is closed by a radial cover-shell 6 of the front casing-part 2 , and a fairing 30 of the casing-part 2 projects into a cylindrical rim 13 of the nozzle-mount 11 to establish a flow-path of reducing cross-sectional area into the duct 14 . Location of the motor 22 peripherally of the casing 2,3 and its batteries in projecting pods 31 facilitates their cooling by water external to the casing 2,3.

1 . A diver-propulsion unit comprising: a propeller for providing propulsion thrust of the unit: mounting means defining a cylindrical duct-portion, means mounting the propeller for rotation coaxially within the cylindrical duct-portion; a motor mounted on the mounting means externally of the cylindrical duct-portion; and coupling means for coupling the motor to the propeller to drive rotation of the propeller. 
     
     
         2 . The diver-propulsion unit according to  claim 1 , wherein the mounting means comprises a nozzle-mount having a forward annular part for intake of water, and a rear part defining the cylindrical duct-portion, the forward annular part extending to the cylindrical duct-portion for defining an intake-water path into the cylindrical duct-portion for the intake of water. 
     
     
         3 . The diver-propulsion unit according to  claim 2 , wherein the intake-water path is of reducing cross-sectional area into the cylindrical duct-portion. 
     
     
         4 . The diver-propulsion unit according to  claim 2 , wherein the forward annular part of the nozzle-mount includes a radially-extending channel, and wherein the coupling means includes drive means that extends within the channel for coupling the motor drivingly to the propeller. 
     
     
         5 . The diver-propulsion unit according to  claim 4 , wherein the drive means comprises one of a belt-drive, a chain-drive and a shaft-drive. 
     
     
         6 . The diver-propulsion unit according to  claim 4 , wherein the motor is coupled to the drive means via gearing. 
     
     
         7 . The diver-propulsion unit according to  claim 4 , wherein the drive means is coupled to the propeller via gearing. 
     
     
         8 . The diver-propulsion unit according to  claim 1 , having an external casing enclosing the mounting means and the motor. 
     
     
         9 . The diver-propulsion unit according to  claim 8 , wherein the external casing comprises a front-casing for defining a water inlet to the diver-propulsion unit, and a rear-casing for defining a water outlet from the diver-propulsion unit. 
     
     
         10 . The diver-propulsion unit according to  claim 9 , wherein the propeller is mounted within the cylindrical duct-portion on a drive-shaft that extends axially of the cylindrical duct-portion, and wherein the drive-shaft has front and rear ends journalled respectively in front and rear portions of the rear-casing. 
     
     
         11 . The diver-propulsion unit according to  claim 10 , wherein the coupling means includes means for coupling the motor to the front end of the drive-shaft for driving the propeller in rotation, and wherein the means for coupling the motor to the front end of the drive-shaft comprises a first pulley coupled to the motor for rotation by the motor, a second pulley coupled to the front end of the drive-shaft for rotating the drive-shaft, and a belt-interconnection between the first and second pulleys for conveying rotation of the first pulley to the second pulley. 
     
     
         12 . The diver-propulsion unit according to  claim 11  wherein the first and second pulleys are mounted on shafts journalled in respective parts of the front-casing. 
     
     
         13 . The diver-propulsion unit according to  claim 11  wherein the front-casing comprises a peripheral rim and a cover for the belt-interconnection, the cover for the belt-interconnection extending radially of the peripheral rim of the front-casing. 
     
     
         14 . A diver-propulsion unit comprising: a nozzle-mount that includes a cylindrical duct; the nozzle-mount defining a water-flow path through the cylindrical duct; means mounting a propeller for rotation coaxially within the cylindrical duct; motor means mounted on the nozzle-mount outside the water-flow path through the cylindrical duct; and coupling means for coupling the motor to the propeller for rotating the propeller to create thrust for propulsion of the diver-propulsion unit. 
     
     
         15 . The diver-propulsion unit according to  claim 14 , having an external casing enclosing the nozzle-mount and the motor. 
     
     
         16 . The diver-propulsion unit according to  claim 15 , wherein the external casing is cylindrical with a bulge portion housing the motor. 
     
     
         17 . A diver-propulsion unit comprising: a cylindrical duct; means defining a water-flow path through the cylindrical duct; means mounting a propeller for rotation in the water-flow path coaxially within the cylindrical duct; motor means mounted outside the water-flow path through the cylindrical duct; and coupling means for coupling the motor means to the propeller for rotating the propeller to create thrust for propulsion of the diver-propulsion unit. 
     
     
         18 . The diver-propulsion unit according to  claim 17 , including an external casing to the cylindrical duct and the motor means, the external casing comprising a front-casing for defining a water inlet to the water-flow path, and a rear-casing for defining a water outlet from the water-flow path. 
     
     
         19 . The diver-propulsion unit according to  claim 18 , wherein the propeller is mounted within the cylindrical duct on a drive-shaft that extends axially of the cylindrical duct, and wherein the drive-shaft has front and rear ends journalled respectively in front and rear portions of the rear-casing. 
     
     
         20 . The diver-propulsion unit according to  claim 17 , wherein the coupling means comprises drive-transmission means for transmitting drive from the motor means to drive the propeller in rotation, the drive-transmission means including means to convey the drive from the motor means to the propeller transversely through the water-flow path.