Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H23/00—Transmitting power from propulsion power plant to propulsive elements
  • B63H23/32—Other parts
  • B63H23/321—Bearings or seals specially adapted for propeller shafts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H23/00—Transmitting power from propulsion power plant to propulsive elements
  • B63H23/32—Other parts
  • B63H23/34—Propeller shafts; Paddle-wheel shafts; Attachment of propellers on shafts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
  • F16D3/16—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts
  • F16D3/18—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts the coupling parts (1) having slidably-interengaging teeth
  • F16D3/185—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts the coupling parts (1) having slidably-interengaging teeth radial teeth connecting concentric inner and outer coupling parts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H23/00—Transmitting power from propulsion power plant to propulsive elements
  • B63H23/32—Other parts
  • B63H23/321—Bearings or seals specially adapted for propeller shafts
  • B63H2023/322—Intermediate propeller shaft bearings, e.g. with provisions for shaft alignment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H23/00—Transmitting power from propulsion power plant to propulsive elements
  • B63H23/32—Other parts
  • B63H23/321—Bearings or seals specially adapted for propeller shafts
  • B63H2023/325—Thrust bearings, i.e. axial bearings for propeller shafts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H23/00—Transmitting power from propulsion power plant to propulsive elements
  • B63H23/32—Other parts
  • B63H23/321—Bearings or seals specially adapted for propeller shafts
  • B63H2023/327—Sealings specially adapted for propeller shafts or stern tubes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D1/00—Couplings for rigidly connecting two coaxial shafts or other movable machine elements
  • F16D1/06—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end
  • F16D1/064—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end non-disconnectable
  • F16D1/068—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end non-disconnectable involving gluing, welding or the like
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
  • F16D3/84—Shrouds, e.g. casings, covers; Sealing means specially adapted therefor
  • F16D3/843—Shrouds, e.g. casings, covers; Sealing means specially adapted therefor enclosed covers

Definitions

• the present invention refers to a transmission for boats, as well as to a boat equipped with such a transmission .
• the present invention refers to a transmission for boats with a fixed type surface, i.e. non-steering and not adjustable during sailing, characterised by simplicity and cost-effectiveness of construction, as well as by compactness and high propulsion efficiency.
• Figures 4A-4E show some different types of boats. From a brief analysis, each of them will lead to a clear indication of the peculiar advantages and drawbacks. On the other hand, from the description it will emerge how the present invention allows all of the different advantages of the different types of boats to be combined in a unique embodiment, avoiding their drawbacks.
• Figure 4A shows a traditional propeller shaft line transmission immersed with through-hull of the shaft directly in the bottom. Such an embodiment shows a high angle of inclination of the propeller shaft with respect to the horizontal.
• a boat to compare it with the others, which have all been aligned starting from the transom, has an unacceptable inner bulk in terms of the rational exploitation of the spaces.
• the costs of making such a boat are not high at the expense, however, of a low efficiency of propulsion with respect to the other cases of the prior art due to the high angle of inclination of the propeller shaft and of the advanced position of the barycentre, due to the position of the motor group.
• Figure 4B shows the typical installation of a surface propeller transmission system with a small angle of the propeller shaft with respect to the horizontal.
• the external bulk is remarkable because, in order to have the propeller in a correct work position, the shaft must have a much greater length, for example with respect to the boat 4E, and, consequently, it is necessary for the hull to have a so-called tail that performs the task of being able to install the propeller shaft support and the rudder.
• the production costs are high, greater than case 4E, whereas the efficiency of propulsion of the two cases is comparable.
• Figure 4C shows the case of surface transmissions of the articulated type that have an internal bulk that is comparable to boats 4B and 4E.
• the transmission is supported directly by the transom and, for this reason, it is not necessary for the hull to extend from this side, as happens, on the other hand, for embodiment 4B.
• the overall bulk is also similar to the previous one and greater than case 4E.
• the manufacturing costs are greater than boat 4B, the possibility of steering and varying the inclination of the transmissions in progress makes the propulsion system more complicated and expensive, and much greater than case 4E.
• the efficiency of propulsion is comparable both to boat 4B and to boat 4E.
• Figure 4D shows the case of sterndrive transmission systems that results much more compact than the previous ones, both inside and outside the hull, also because usually it does not need a mechanical inverter group, since this part is generally included in the so- called "sterndrive".
• the transmission therefore, is competitive with case 4E with regard to bulks, the cost is higher, whereas efficiency of propulsion is lower, due to the complexity of the two bevel gear pairs which a "sterndrive" is equipped with, both with respect to boat 4E and boats 4B and 4C.
• Figure 4E shows the type of boat according to the present invention. While maintaining an external bulk beyond the transom that is comparable to the compact boat 4D, it has internal bulks and efficiency of propulsion comparable to cases 4B and 4C, whereas the efficiency of propulsion is greater with respect to 4A and 4D but, in particular, the cost is lower with respect to all the previous cases.
• the purpose of the present invention is to make a transmission that is alternative to the known ones and particularly efficient.
• the purpose of the present invention is to make a transmission that is cost-effective, compact and that at the same time offers high efficiency of propulsion .
• the propeller shaft on the side opposite the propeller, comprises a gear sleeve with spherical teeth welded thereto.
• a gear sleeve performs the function of a "simplified" joint for the transmission of the movement that comes from the motor- inverter group.
• This coupling is called “simplified” because it does not require intermediate transmission elements, joints of various kinds, instead it allows, through flanging and another toothed sleeve, the movement to be transmitted and to absorb, within a certain limit, alignment errors.
• the transmission is not equipped with an actual thrust bearing, instead the thrust is discharged from the inner end 29 of the shaft 12 on a bronze billet 18 fixed to a first flange 19 that, in turn, by fastening to a second flange 20, discharges the thrust on the inverter 25 (only schematically shown) .
• This is possible thanks to the particular configuration of the transmission shaft, which includes a toothed spherical joint at one end, welded to the shaft, as it will be detailed further hereinafter.
• the projection angle 21, formed by the shaft 12 with the construction line, in other words the base line 22 of the boat, does not have the ideal inclination close to 0°, but the value of such an angle can be up to 10°.
• the distribution of the weights will also be such as to promote the efficiency of propulsion, d) In order to keep the efficiency of propulsion at the maximum possible level, i.e.
• this transmission system uses a propeller 15 the blades of which have the characteristic of having a high positive, or backwards, rake angle, close to 15°, such as to make the thrust as horizontal as possible.
• FIG. 1 shows a section view of the transmission for boats according to the present invention
• figure 2 shows an enlarged detail of the transmission of figure 1 of the present invention
• FIG. 4E schematically show some different types of boats where figure 4E corresponds to the boat set-up in which the transmission for boats according to the present invention is installed;
• FIG. 5A and 5B show a side view and an axonometric view of the end of the shaft 12 to which the gear sleeve 30 31 has already been welded, in order to highlight how such a gear sleeve and the spherical cap 29 are ideally obtained from a unique spherical body;
• FIG. 6 and 7 show an embodiment analogous to that of figures 1 and 2 in which, however, the spherical toothing of the gear sleeve 30 31 and the spherical cap 29 are not obtained from a unique spherical body, but from spherical bodies of different radii.
• a transmission for boats according to the present invention is shown with 10.
• the shaft 12 of the propeller is a practically cylindrical element, with constant section, worked at both ends.
• a diameter-reducing cone 23 is provided, which brings the diameter from the maximum one of the shaft to that of the propeller hub.
• the so-called "ribbing and grooving" 24 is obtained for the installation of the propeller 15 in turn fixed through a nut 25 screwed to the threaded front core 26.
• this cylindrical fore part 28 of the shaft 12 does not end with a flat front surface, but with a spherical cap 29, of radius R, the function of which will be explained hereinafter.
• the cylindrical portion 28 performs the function of being able to fit a sleeve 30 onto the shaft with an outer gear with a spherical toothing 31.
• the gear sleeve 30 31 is then welded 32 to the shaft 12 to make it a unique piece. It should be noted that the spherical cap 29 projects from the plane formed by the gear sleeve 30 31.
• the task of the spherical cap 29 is to discharge the thrust of the propeller 15 during the forward travel also in rotation with a different angle from the theoretical ideal alignment angle.
• the spherical cap 29 transfers the thrust to a billet or plate 18, preferably made of bronze or another anti-friction material, at the centre of which a spherical cavity is obtained, through mechanical processing by removal of material, said cavity having a radius equal to that of the spherical cap 29 of the end of the shaft 12.
• This billet or plate 18, which acts as a bearing brass is in turn fixed through a suitable centring system to a coupling flange 19 with the exit flange 20 of the inverter 25.
• the flanges 19 and 20 are in turn coupled to a toothed sleeve 34 that transmits the movement to the shaft through coupling with the gear sleeve 30 31.
• the toothed sleeve 34 preferably has straight teeth.
• This angle in any case small, is such as not to reduce the maximum admittable design torque and power values.
• Figure 5 shows how the gear sleeve 30 31 and the spherical cap 29 can ideally be obtained from a unique spherical body.
• Figures 6 and 7 show a different embodiment in which the spherical toothing of the gear sleeve 30 31 and the spherical cap 29 are not obtained from a unique spherical body, but from spherical bodies of different radii .
• a front seal system 39 fixed to the shaft 12 and rotating with it, which act on a static counterface 40, preferably made of ceramic.
• a counterface 40 is kept in position through strapping 42 by a bellows rubber cap 41 that, in turn, is fixed through strapping 42 to a flange 43 bolted to the internal side of the transom 11.
• the bellows cap 41 is mounted with a compression pre-load.
• the passage duct 14 from the inside to the outside the shaft 12 is obtained by moulding with the fibreglass hull and therefore forms a unique piece with it.
• the support of the shaft 12 consists of a stainless steel tube 46 slightly longer than the passage duct 14, so as to face inside the engine room in which the propulsion- inverter groups are installed.
• FIG. 3 is a view of the aft of a hull arranged for the installation of the transmission sub ect-matter of the present invention. In such a view the shaft 12 and the propeller 15 are not shown.
• Figure 3 has the purpose of showing the symmetrical installation of the transmission and, at the same time, clarifies the reciprocal position of some components, a position that is not clear in the view/longitudinal section of figure 1.
• the installation test is carried out under ideal alignment conditions, i.e. so that the angle formed by the propeller shaft 12 with the exit shaft of the inverter be null.
• the shaft 12 is stiffened, i.e. the existing tolerances or clearances are set to zero.
• toothed sleeve 34 with the whole motor-inverter group connected thereto, can be inserted inside the cavity of the equivalent cap 37 only perfectly aligned with the propeller shaft 12.
• the installer can compare the ideal alignment thus obtained with the support structure of the motors in the engine room, which will preferably be pre-moulded from fibreglass, and take whatever measures he/she considers most suitable and effective.
• These can consist in adapting the structure or the interfaces between structure and motor-inverter group or, if the alignment error angle between propeller shaft 12 and support structures of the motor-inverter group is less than the tolerance angle ensured by the spherical gear sleeve 30 31, the installer can evaluate whether to exploit this tolerance and not to carry out any intervention.
• the transmission 10 for boats of the present invention is compact and cost-effective, without having a negative impact on propulsion, thanks to the fact that the inner end of the shaft 12 is associated with a "simplified" direct coupling 17 with the inverter 25 of the boat in the absence of joints, for example homokinetic joints, between shaft 12 and inverter 25.
• a connection is made through a spherical cap 29 at the end of the shaft, said spherical cap 29 being associated with a plate 18 that acts as a bearing brass, at the centre of said plate a complementary spherical cavity is obtained having the same radius as the spherical cap 29.
• Such a plate 18 is integral at the rear with a first flange 19 coupling with a second flange 20 exiting from the inverter 25.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Ocean & Marine Engineering (AREA)
• General Engineering & Computer Science (AREA)
• General Details Of Gearings (AREA)
• Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)

Priority Applications (1)

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Publications (1)

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ID=53052966

Family Applications (1)

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Citations (6)

Family Cites Families (2)

• 2016
  • 2016-02-26 CN CN201680004921.2A patent/CN107108007B/zh active Active
  • 2016-02-26 WO PCT/IB2016/051061 patent/WO2016135686A1/en active Application Filing

Patent Citations (6)

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