Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H5/00—Arrangements on vessels of propulsion elements directly acting on water
  • B63H5/07—Arrangements on vessels of propulsion elements directly acting on water of propellers
  • B63H5/125—Arrangements on vessels of propulsion elements directly acting on water of propellers movably mounted with respect to hull, e.g. adjustable in direction, e.g. podded azimuthing thrusters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B2211/00—Applications
  • B63B2211/06—Operation in ice-infested waters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H5/00—Arrangements on vessels of propulsion elements directly acting on water
  • B63H5/07—Arrangements on vessels of propulsion elements directly acting on water of propellers
  • B63H5/125—Arrangements on vessels of propulsion elements directly acting on water of propellers movably mounted with respect to hull, e.g. adjustable in direction, e.g. podded azimuthing thrusters
  • B63H2005/1254—Podded azimuthing thrusters, i.e. podded thruster units arranged inboard for rotation about vertical axis
  • B63H2005/1258—Podded azimuthing thrusters, i.e. podded thruster units arranged inboard for rotation about vertical axis with electric power transmission to propellers, i.e. with integrated electric propeller motors

Definitions

• the present invention relates .to a propulsion arrangement as disclosed in the preamble of claim 1 ' and, correspondingly, to a method in accordance with claim 8.
• the present invention relates to such a ship's propulsion arrangement which includes a separate propulsion device housing which comprises a motor and a propeller, wherein said housing extends outwards from the ship's hull and is turnable by means of primary power transmission means which include especially mechanical components.
• the present invention also relates to a method for the management of exceptional forces in connection with such a propulsion arrangement which extends outwards from the ship's hull and which can be turned by means of power transmission means which suitably include mechanical components.
• Such ship's propulsion means wherein a propeller is arranged at a structure which is separate from the hull and which structure, as such, can be turned and by means of which turning the propeller stream can be directed into a desired direction are well known in the maritime field.
• the motor can be located at any suitable place. If the motor is located within the hull the arrangement is usually such that the drive power to the propeller is transferred via a shaft and a bevel gear arrangement.
• an especially favorable embodiment of such a propeller arrangement includes a separate housing structure, a so called “pod”, which usually is designed in a favorable shape with respect to the water stream, in which pod the driving motor for the propeller, in most cases an electric motor, is located.
• a so called “pod” which usually is designed in a favorable shape with respect to the water stream, in which pod the driving motor for the propeller, in most cases an electric motor, is located.
• the propulsion system brought into the market under applicant's trade mark "Azipod” (TM) can be mentioned.
• this kind of structure brings about a number of considerable advantages and for this reason such propulsion arrangements nowadays are adapted to the most various types of vessel.
• the housing structure at a propulsion arrangement as discussed above constitutes this kind of structure extending outside from the ship's hull.
• this kind of housing structure is arranged in a fixed manner to an arm structure which, in turn, is arranged in a turnable manner to the ship's hull in such a way that said housing and its propeller (s) are located below the vessel at a location which is hydrodynamically and operationally appropriate.
• an installation location is usually arranged in such a way that the propulsion device, as such, will be located within the ship's outermost extent and is thus in a way sheltered.
• a turning rim or collar which in most cases is toothed, is arranged at the upper end of the arm, at which turning rim a turning motor for turning the housing is arranged.
• This motor is controlled by the ship's steering arrangement, and may as such be of any kind suitable to this purpose.
• the power connection between the turning motor and said turning rim is arranged by means of a pinion gear arrangement so that the turning, motor acts directly at said turning rim and thus brings about a turning of the arm and the housing structure attached thereto.
• the propeller is often considered to be the most vulnerable part of the arrangement the exchange of a broken propeller is not a very complicated task, as such.
• repairing or exchanging a turning machinery or a part thereof may often be a task of considerable complexity, especially due to the fact that the location of the machinery or its elements is often very inconvenient.
• the problem has until now been solved by dimensioning the entity comprising the turning rim and the turning motor considering also the stress calculated to constitute a predictable result of the exceptional forces included in the bases of dimensioning.
• the parts of a turning arrangement are often heavily oversized in relation to the actual function.
• the object of the present invention is to solve the aforesaid problem so that a turning arrangement is achieved which is safer than known arrangements and wherein the dimensioning, however, can be based on the loads relating to the daily use.
• a further object of the present invention is to disclose such an arrangement wherein an overload caused by even an extreme exceptional load does not bring about any permanent damage to the apparatus but where the ship ' s performance without any separate measures is guaranteed also after, e.g., a light grounding, and especially so that a resetting of any security arrangement, and thus a continuing of the safe operation, generally- require no separate actions .
• one object of the present invention is also to- disclose such an arrangement which renders possible a use also of such turning arrangements which earlier have been considered impossible or at least inappropriate .
• One further object of the present invention is also to dis- close such an arrangement wherein the need for service is as low as possible while the security still remains to its original extent .
• an arrangement according to the present invention is characterized in that sliding means including a dampening arrangement are arranged on the path of power transmission between said housing and the ship's hull, wherein said sliding means enable an additional relative turning of the propulsion means independently of a forced control by the main power transmission means .
• the method according to the present invention is characterized therein that the propulsion device, due to the impact of an exceptional force and by means of sliding means including a damping arrangement is brought to turn in relation to said main power transmission means or some of their components.
• Figure 1 discloses as a general side view a part of a ship, at which a turning propulsion device known per se is installed,
• Figure 2 discloses in a corresponding sectional view the general arrangements for a known propulsion device
• Figure 3 discloses schematically and seen from above the general arrangement for one embodiment in accordance with the present invention, wherein the " damping primarily is based on a function of friction surfaces,
• Figure 4 discloses as a partially enlarged view the arrange- ment according to Figure 3 as a section taken along line A-A,
• Figure 5 discloses in a corresponding manner the general arrangement of Figure 3 as a section taken along line B-B, where the turning arrangement, however, as such has been arranged in accordance with an alternative implementation, and
• Figure 6 discloses schematically how the power impact acting on the propulsion device develops as a function of time when a device in accordance with one embodiment ⁇ of the present invention is. operating.
• a propulsion arrangement for a vessel 1 includes, as known per se, a housing structure 3 having a propeller 2 arranged at at least one end thereof, which housing among professionals in the field usually is called "pod" .
• a vessel can have several such pods, which can be arranged at the stern as well as at the bow of the vessel.
• a pod 4 includes a main housing structure 3 as well as an arm portion -6 connecting it to the vessel's 1 hull 5.
• said arm portion 6 further includes wings 7 acting as a kind of rudder surface, as disclosed in more detail in Figure 2.
• the actual housing portion 3 and its arm 6 are turnable around an axis which extends transversely in relation to the vessel 1, favorably essentially vertically ⁇ around a t ⁇ rning axis C-C, in which case the apparatus entity at the same time acts both as the a pushing or propulsion device of the vessel 1 as well as as the its steering means, i.e. as a- rudder.
• Figure 2 discloses that the actual propulsion unit favorably includes an electrical motor inside said housing 3, as well as any possible other .means for rotating the propeller 2.
• a known arrangement as disclosed in F_igure 2 comprises a tooth wheel rim 8 arranged at the upper end of said arm portion 6, which rim is rotated by means of a pinion wheel 10 rotated by a motor 9 in accordance with steering commands given at the ship's bridge 11.
• the arrangement further includes bearing and sealing arrangements for the arm, which arrangements, as known per se, are disclosed in Figure 2 only allusively.
• said tooth wheel rim 8 , the structure of said turning motor 9 as well as said pinion wheel 10 are usually dimensioned taking into account exceptional forces caused by an accident or by extreme conditions, so that the structures as such stand also the loads caused by, e.g., blocks of ice or even by a light grounding.
• loads primarily cause a tendency for the propulsion device to turn away from the direction indicated by the turning motor 9. Since such an application of force due to an exceptional shock torque caused by a blow can •be manifold in relation to the turning force required for the normal steering of the vessel this has in practice lead to that said elements, i.e. said tooth wheel rim 8, turning motor 9, and pinion wheel 10 in fact by necessity have bee dimensioned too heavily.
• Figure 3 discloses, seen from above, a new turning rim arrangement in accordance with one embodiment of the present invention, which arrangement, as such, can be adapted instead of a prior art turning rim 8 as disclosed in Figure 8 , favorably even so that an arrangement according to the present invention also can be adapted as a retrofitting to existing propulsion devices .
• the toothed part of the turning rim is shown to have an internal toothing, but a turning rim having an external toothing as disclosed in ⁇ Figure 2 is also possible, as is disclosed in more detail in Figure 5.
• the turning rim arrangement according to the present invention includes at least two- parts which at least to a limited extent are mutually movable, i.e. mainly rotatable, where one of said parts, i.e. the actual turning rim 8', is in connection with the turning machinery 9, e.g., with said pinion wheel 10 or, in the case disclosed in Figure 5, via a worm wheel 20.
• the other part of the turning arrangement in the disclosed embodiment a turning collar 12 , is arranged in such a way that it is in an operational, i.e. a power transmitting, contact with the propulsion device 4, that is mainly with its arm portion 6.
• slip damper means are arranged in accordance with the present invention, by means of which the energy caused by the slipping can be controlled without damage to the actual drive means 8', 9, 10 20.
• Figures 4 and 5 disclose an arrangement according to one favorable embodiment of the present invention, where the damping is achieved utilizing means including mutually interacting friction surfaces 13, 13a, 13b.
• Figure 4 which discloses a section A-A of Figure 3
• a friction ring portion 14 of said tooth rim 8' is arranged into pressure between a turning collar 12 constituted by two superimposed parts 12a and 12b.
• the possibility of a relative movement between parts 8 ' /14 and 12a/l2b has been achieved, which in Figure 3 is presented by arrows in opposite directions. Due to the properties of the co-operating frictional surfaces 13, 13a, 13b and a favorable arrangement according to one embodiment of the present invention this relative movement can be very controlled very strictly as disclosed in more detail below.
• Figure 4 show that said tooth rim 8 ' favorably is arranged at the turning collar assembly 12, 12a, 12b in such a way that said turning rim 8 ' is centered by said turning rim assembly 12, 12a, 12b. In tangential direction, however, said turning rim 8 ' remains in contact with said turning collar assembly only via the frictional forces acting between said friction surfaces 13, 13a, 13b.
• Said turning collar assembly is in turn favorably in operational contact with the arm portion 6 of the propulsion device 4, e.g., via guiding pins 15 which mutually center said turning collar portions 12a, 12b, directly by means of an arrangement according to Figure 5 or in some other way known per se for achieving a shape lock connection so that the rotative torque of both said collar 12a and said collar 12b will be transferred to the propulsion device 4 and thus enables it to be turned in a desired way.
• the actual turning assembly is favorably fitted in a installation block 17 by means of a bearing arrangement 16 and other arrangements known per se required by the operation (not shown) which installation block in its turn, in a manner known per se, is attached to the hull 5 of the vessel 1.
• FIG. 5 which partially discloses a section B-B of Figure 3 said turning collar portions 12a, 12b in accordance with an especially favorable embodiment of the present invention, are mutually connected by means of a screw assembly 18 so that the normal force of said turning collar portions 12, 12a, 12b can be adjusted at least in the region of said friction portions 13, 13a, 13b.
• a cup spring 19 or the like resilient member is arranged at said screw assembly 18.
• Such a resilient member renders possible, by utilization of the tightening torque acting at said screw assembly 18, a very exact adjustment of the normal force acting at said friction surfaces 13 and thus also of the friction acting between said tooth rim 8 ' and said turning collar 12.'
• FIG 6 schematically discloses an example of how an impact force "F" directed towards a propulsion device 4 can develop as a function of time "t", e.g., when a vessel 1 meets an unforeseen obstacle such as a block of- ice, a stone or even a wrongly arranged quay structure so that the propulsion device hits the obstacle.
• F Q represents a turning force considered normal in view of the normal steering operations ' and for which a conventional turning apparatus 8, 9, 10 and 20 must.be dimensioned in any case.
• the starting friction force "F ⁇ " acting between the co-operating friction surfaces 13, 13a, 13b and thus also the device's disengagement torque with respect to an excessive stress can be set very easily and securely into accordance with a required safety torque by adjusting the torque at the tightening screw assembly 18.
• thi-s torque depends on many structural factors, of which especially the size, surface structure and material of said friction surfaces 13, 13a, 13b can be mentioned.
• the management of energy leads to a heating of the friction surfaces.
• the energy build-up during, e.g., about three seconds can be in the order of, e.g., about 3 MW, which energy in one structure in accordance with the present invention causes a rise .of temperature of about 80°.
• a rise in temperature does not constitute any problem, as such, since the heat will be distributed essentially evenly into the friction ring portion 14 of the tooth rim 8' and, correspondingly, into the turning collar 12.
• a separate cooling arrangement (not shown) can be arranged in connection with said elements.
• said friction arrangement 13 is built up as a multi-layer lamellated structure, and in another embodiment the arrangement comprises special wedge elements by means of which the press force between said elements 12a, 12b, 14 can, e.g., be momentarily raised by actively operating means.
• the disclosed arrangement further brings the advantage that, e.g., the retrieval of the steering function does not require any separate arrangements or measures taken by the operator, perhaps except for , a check of the tightening torque at said screw assemblies 18, e.g., in connection with normal maintenance of the vessel.
• the slip between said tooth rim 8 ' and said turning collar assembly 12 will be maximally 180° (i.e. the propulsion device 4 turns totally into the opposite direction) , after which the starting friction between the friction surfaces 13, 13a, 13b by itself has the effect that the grip between the tooth rim 8 ' and the turning collar assembly 12 again will correspond to the detachment force "F ⁇ ". of the starting friction.
• any position indication sensors (not shown) usually necessary for the steering operation and known per se are arranged at the main structure of the propulsion arrangement 4, i.e. in connection with, e.g., said arm portion 6, in which case the position between said turning collar 12 and said tooth rim 8', or any dislocation of said position, actually has no impact on the vessel's steering arrangements.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Gear Transmission (AREA)
• Transmission Devices (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8559154

Family Applications (1)

Country Status (3)

Cited By (2)

Families Citing this family (1)

Citations (2)

• 2000
  • 2000-09-25 FI FI20002108A patent/FI109680B/sv active
• 2001
  • 2001-09-14 WO PCT/FI2001/000799 patent/WO2002024522A1/en active Application Filing
  • 2001-09-14 AU AU2001287771A patent/AU2001287771A1/en not_active Abandoned

Patent Citations (2)

Also Published As

Similar Documents

Legal Events