Marine propulsion – Jet drive – Direction control for fluid jet
Patent
1989-11-16
1991-02-12
Peters, Jr., Joseph F.
Marine propulsion
Jet drive
Direction control for fluid jet
440 38, B63H 1111
Patent
active
049920650
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a jet propulsion assembly for ships, and in particular to a reversing device of such assemblies.
A jet propulsion assembly for ships basically includes a propeller pump, which generally is mounted at the ships stern and has an inlet connected to an inlet opening in the bottom of the ship, forward of the pump. The propeller pump outlet is generally connected to a steering means, which is laterally pivotal around a vertical axle for steering the driving water jet, and connected to a reversing device adapted to be raised and lowered around a horizontal axle for diverting the driving water jet from straight or obliquely rearwards, or straight or obliquely forwards/downwards.
The reversing device of the jet propulsion assembly is normally constructed so that one or several shovel-shaped members can be pivoted horizontally into the driving water jet from the pump to gradually divert the jet. The shovel-shaped members and their suspension points in relation to the steering means and pump are normally positioned so that the water jet will lock the shovel-shaped members in their maximally pivoted positions, in which the water jet is directed obliquely forwards/downwards. Such a known reversing device is disclosed by for example the Swedish patent application No. 8200417-7. This has, as do similar reversing devices, the disadvantage that a considerable force is required to return the shovel-shaped members to their original positions, in which the jet can pass freely straight backwards. It is appreciated that this can give rise to certain risks as the ship is being manoeuvered to change from reverse drive to forward drive. The jet is constantly counteracting the opening of the shovel-shaped members, which can lead to that the ship continues to drive backwards, despite the intention to drive the ship forwards.
The purpose of the present invention is to overcome the above problems and to provide a reversering device of a jet propulsion assembly for ships, wherein the outgoing jet does not strive to lock the shovel-shaped members in their maximally reset positions, at the same time as it effectively diverts the water jet gradually as required.
The object of the invention as well as the characteristic feature thereof appear from the accompanying patent claims.
The invention will be further described below, in conjunction with the attached drawings, wherein
FIG. 1a is a schematical longitudinal section of a jet propulsion assembly with a reversing device according to the invention, wherein the reversing device is shown in its inactive state,
FIG. 1b is a view corresponding to FIG. 1a, and showing the reversign device in its fully reversing state,
FIG. 2 is a schematic, vertical section of the rear portion of a jet propulsion assembly, where the reversing device according to the invention is illustrated by full lines in its inactive state, and by dashed lines in its fully reversing state, and
FIG. 3 is a partially sectioned top view of the jet propulsion assembly in FIG. 2.
The jet propulsion assembly according to the drawings is schematically shown in its position at the stern of a ship, of which only the stern 1 and bottom 2 are implied. The jet propulsion assembly includes an inlet canal 3 extending from a water inlet 4 in the ship bottom 2 to a mounting flange 5 for the pumping house 6 of the assembly. The inlet 4 is provided with a grid 7, which prevents objects from being sucked into the jet propulsion assembly. The pump is comprised of a propeller pump having a hub casing 8, which is provided centrally in the flow way through the pumping house 6. The hub casing 8 is supported by articulated vanes 9. The pump wheel 11 is journalled in the hub casing 8 and is driven from a not further shown driving machinery in the ship by a drive shaft 10.
The outlet side of the pump housing 6 is connected to an outlet pipe 15, over which a laterally pivotal steering means 20 is mounted. The steering means 20 is journalled in vertically positioned axle spindles 16 and 17 and is laterally swiveled arou
REFERENCES:
patent: 2735264 (1956-02-01), Jewett
patent: 3531940 (1970-10-01), Markowski
patent: 4212442 (1980-07-01), Fage
Lundberg Nils E.
Torneman Gerard
MJP Marine Jet Power AB
Peters Jr. Joseph F.
Swinehart Edwin L.
LandOfFree
Reversing device of a jet propulsion assembly for a ship does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Reversing device of a jet propulsion assembly for a ship, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reversing device of a jet propulsion assembly for a ship will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-17996