Patent Application
20100260606
The present invention refers to a nautical propeller provided with multiple pitch regulations comprising a hub, a drive shaft, an outer case constrained to the hub, and one or more blades constrained to the outer case such that to be able to rotate around their own shaft. The outer case of the propeller is able to make to rotate each blade around the hub axis. Further, the propeller provides a device for multiple regulation of the angular position of at least one blade around its own shaft relatively to the hub.
The devices of the known art provide different means for regulating the propeller pitch that can be both mechanical and hydraulic. Such devices could be driven by both automatic and manual systems, and could have both continuous and discrete regulations. Patent WO-A-90/11221, in the name of Marine Propeller SRL, describes a manually regulated variable-pitch propeller provided with a central hub, an outer case having an annular shape coaxial with the central hub around which it could relatively rotate, with blades able to rotate around both their own axis and the pinion axis, a device for manual regulating the propeller pitch. The central hub is provided with a pinion engaging with the other component of the crown wheel and pinion, that is the crown wheel, placed at the shaft end of each blade. Every propeller has one more constraint, rotatable with the outer propeller body thanks to which it is made to rotate around the hub axis. When the outer propeller body is rotated relatively to the central hub, every blade is subjected to a rotation both around the axis of the central hub, because of the constrain with the outer propeller body, and around its own axis because of the claw clutch of the crown wheel placed at every blade base, with the pinion rigidly constrained to the propeller hub. The manual regulating device of such a propeller, coupling the outer case to the hub, provides a fixed coupling with the outer case and a decoupling device from the central hub used during the regulating step of the propeller pitch.
Variable-pitch propellers are known as well, wherein the regulation of the propeller pitch may be obtained, during the boat motion too, by a servo-control that, activated by the operator, is able to force a controlled rotation of a crown wheel, coaxial with the propeller hub and rotatably mounted thereon, engaged with the pinion of which every blade shaft is provided with.
For example, the European Patent EP-A-0328966 in the name of BIANCHI S.r.l., teaches how to realize a variable-pitch propeller wherein a fluidic operated ram induces the shift of a toothed sleeve that, conveniently shaped, adapted to cause the controlled rotation of a convenient annular crown wheel, rotationally constrained to the propeller hub. The annular crown wheel, in its turn, by a predefined number of teeth, engages the pinions integral with the propeller blade shafts. The ram manually operating causes the crown wheel and pinions rotation, thereby provoking the incidence angle variation of the blades themselves, that is the propeller pitch.
One of the drawbacks in such propellers of the known art, most of all in case of manually regulated propellers, is that for obtaining a fine regulation of the propeller pitch, it is necessary to provide the crown wheel with a great number of teeth, which drives, by the corresponding pinions, the blade rotation around their pivot axis to the propeller hub. So, to obtain a good accuracy in the propeller pitch regulation, it is necessary to realize crown wheels with an extremely great number of teeth (for example 100-200 teeth), with the consequent difficulties of realizing such crown wheels, and the hard and slow regulation of such a pitch.
Another drawback of the adjustable and variable-pitch propellers of the known art is that it is not possible to carry out operations of rough regulations for the propeller pitch or operations of fine regulation of the same pitch, at operator discretion. Such problems assume more importance while the range of propeller pitch changing is increasing, and of the required regulation accuracy too.
One of the objects of the present invention is then to realize an adjustable and variable-pitch propeller not presenting the above reported drawbacks of the known art.
It has to be outlined that the propeller pitch, obtained by the afore said manual or aided regulation, may be either the base propeller pitch, for example of a propeller with an automatically variable-pitch, that is for example the one described in WO-A-2008/075187 (in the name of MAX PROP S.r.l.), or the operator-fixed pitch, during the motion too, for example by the device described in EP-A-0328966, or the base propeller pitch of the type described in U.S. Pat. No. 4,140,434, in the name of Massimiliano Bianchi.
It is therefore an object of the present invention to provide an adjustable and variable-pitch propeller wherein it could be possible to carry out an extremely accurate regulation of the propeller pitch (fine regulation), without necessarily having to recourse to mechanical parts difficult to realize and without requiring long times for its regulation.
A further object of the present invention is to realize a propeller wherein it is possible to regulate the propeller pitch both in rough mode and in fine mode, at operator discretion, in an extremely simple manner.
It is finally another object of the present invention to provide a nautical propeller with adjustable and variable pitch, that is simple and effective in regulation and at the same time that it is not complex to realize.
These and other objects are obtained by the adjustable and variable-pitch propeller according the first independent claim and the following independent claims.
The nautical variable-pitch propeller, according to the present invention, comprises a hub driven by the drive shaft, an outer case externally constrained to the hub, and one or more blades. Each blade is constrained to the outer case freely to rotate around the axis of its own shaft. The outer case is able to make to rotate each blade around the hub axis, other than to hold the blades constrained to the propeller. Further the propeller is provided with a mechanical device for regulation of the angular position of at least one blade around the axis of its own shaft relatively to the hub. Advantageously the regulating device comprises at least one moving member and means for transmitting movement from at least one moving member to the shaft of at least one blade, according to at least two different laws of motion transmission.
The presence of at least two different laws (functions) connecting the motion law of the moving member to the motion law of the blade shaft, provides the operator not only a higher flexibility in pitch regulation, but furthermore it aids the fine, or accurate, regulation obtaining, without the need of using complex or difficult to realize mechanisms.
This device in fact may allow to carry out a regulation of the propeller pitch in more steps, starting from a first rough regulation, according to one and/or the other of the at least two laws of motion transmission, and then carrying on with one or more fine regulations for a subsequent and more accurate pitch regulation, thanks to the discrete application, or preferably in cascade, of such at least two laws of motion regulation.
For example, as the person skilled of the art may deduce, by a first motion law it will be possible to regulate the angular position of the blade shafts according to multiples of a first angular range, and with the second law of motion transmission, it will be possible to regulate the same shafts according to multiples of a second angular range, different and eventually shifted relatively to the first.
According to a preferred aspect of the present invention, the mechanical device for regulating the pitch comprises at least two moving members, operable separately and/or jointly one relatively to the other, and two corresponding kinematic systems for transmitting motion from the moving members to the blade shaft (or the shafts of the blades), each one according to its own law of motion transmission, being different from one to another.
Such two regulating kinematic systems may be conformed to provide, at the operating of the two corresponding moving members, two different angular displacements of the propeller blade (or blades), such that the propeller pitch regulation may proceed with high accuracy, both when such kinematic systems are displaced, according to a preferred aspect of the invention, in cascade, and on the other hand when they are displaced so that to separately operate on the blade (or blades).
For example, in a preferred embodiment of the present invention, the afore said kinematic systems for transmitting the motion from the moving members to the propeller blade shaft may comprise two different toothed couplings, with a different tooth number, allowing the moving member rotation, and then the corresponding kinematic chains connecting the moving members from the blade shaft, or the shafts of the blades, of the propeller, according to different angular ranges, such that the operating in cascade of the two moving members causes an extremely accurate regulation of the pitch.
For purposes of illustrations only, and thereby absolutely not limitative, some embodiments of the present invention will be provided with reference to the accompanying drawings, in which:
b are respectively a partial schematic side view, representing a check nut of the drive shaft, and a front schematic view of a propeller, without the check nut of the drive shaft, according to a particular aspect of the present invention.
Referring first to the embodiment shown in
The coupling between the hub 8 and the drive shaft 10 may occur in a plurality of methods, according to a known art, as for example by a spline connection, bayonet base, by clamping screws, interference, etc. It has to be observed that elastic means of different kinds may be comprised too in the coupling between the hub 8 and the drive shaft 10, interposed between the latter, as springs, synthetic joint, etc., herein not represented.
As afore said, each blade 11, in the embodiment herein illustrated, is constrained to the hub 8 thanks to an outer case 6, or shell, presenting on its side surface a plurality of holes, each one being intended for housing the shaft 12 of a blade 11. In the preferred embodiment herein illustrated, each shaft 12 of the blades 11 is constrained to the outer case 6 by a constraint 9 allowing the only rotation of the shaft 12, and then of the corresponding blade 11, around its own axis Y-Y. Further, the blades 11 are likewise constrained necessarily to the outer case 6 such that the potential translating movements of the blades 11 along the propeller axis X-X are opposed by such a further constraint. In this way, when the hub 8 is rotated by the drive shaft, the outer case 6 may make to rotate each blade 11 around the propeller axis X-X, in case wherein the hub 8 too is rotationally integral with the outer case 6.
It has to be noticed that the constraint 9 for the only rotation between each shaft 12 and the case 6 may be realized in different ways known in the art, as for example by a simple contact between the shaft 12 and the corresponding hole of the case 6, or by using a bearing interposed between the shaft 12 and the hole of the case 6, etc.
The case 6, as known in the art, has preferably a substantially cylindrical shape, it may be realized in two or more semi-shells reciprocally laterally attached, and is displaced around the hub 8, to which alternatively it could be constrained integrally, when it would be necessary to transmit the motion of the drive shaft 10 to the blades 11, or rotatably, relatively to the same hub 8, when, as it will be described, it would be necessary to regulate the pitch of the blades 11.
Further, each shaft 12 of the blades 11 is provided with a pinion 5, having the function of allowing the controlled rotation of the corresponding blade 11, and optionally preventing too, because of countering parts, the blades 11 from axially releasing from the case 6.
The afore said mechanical device for regulating the angular position of at least one blade 11 around its own shaft 12 relatively to the hub 8 advantageously comprises, according to the present invention, at least one moving member 1, 7, intended for being directly or indirectly activated by the operator, and for transmitting the motion, by corresponding transmission means Z1, Z2, 2, 5, 6, 9, 13, to at least one shaft 12 of the blades 11, according to at least two different laws of motion transmission.
It has to be observed that herein and afterwards with the term “law of motion transmission” is intended such a function relating the displacement of a determined operating point of the moving member with the displacement of the corresponding shaft 12, or the corresponding shafts 12, of the blades 11.
Specifically, in the herein illustrated embodiment, the regulating device comprises a first substantially annular member 1, axially coupled to the hub 8, and provided with a peripheral crown wheel 13 engaging the pinion 5 of the shaft 12 of at least a blade 11, as well as a second substantially annular member 7, coaxially coupled to the hub 8 and constrained to the outer case 6, thanks to a further toothed coupling 2, so that to can transmit a rotary motion to the latter.
Because the relative rotation of the annular members 1 and 7 relatively to the hub 8 causes, thanks to the kinematic systems 2, 6, 13, 15 afore mentioned, the angular displacement of the blade (or blades) 11, such annular members 1 and 7, that can be manually or by a servo-control operated once released from the corresponding toothed couplings Z1 e Z2, constitute the afore said first and second moving members 1 and 7.
In the embodiment shown in the figures, the peripheral crown wheel 13 of the first annular member 1 engages contemporaneously the pinions 5 of the shafts 12 of every blades 11, and similarly the outer case 6, rotationally integral with the second moving member 7 thanks to the coupling 2, is constrained to every shafts 12 of the blades 11, such that the possible propeller pitch regulation, that is the angular displacement of the blades 11 around their corresponding axis Y-Y, happens in unison.
In the preferred embodiment of the present invention herein described, both the first annular member 1, and the second annular member 7, are respectively removably constrained to the hub 8 by two different toothed couplings Z1 and Z2, such that their rotation around the hub may happen only when the member 1 and/or 7 to be operated is firstly disengaged, from the corresponding toothed coupling Z1 or Z2.
In the propeller of
Then the propeller herein described, the toothed couplings Z1 and Z2 have to be such to allow the disengage of the members 1 and 7 from the hub 8, however without allowing the disengage of the crown wheel 13 from the pinions 5 of the blades 11 and of the member 7 from the outer case 6, respectively.
In such a way, once the members 1 and 7 are released from the hub 8, the rotation of the second moving member 7 causes, thanks to the coupling 2, the corresponding rotation of the outer case 6, that in its turn rotates the blades 11 around the propeller axis X-X, whereas the rotation of the first moving member 1 causes the corresponding rotation of the crown wheel 13 and then, by the pinion 5, of the shafts 12 of the blades 11 around the axis Y-Y of the same shafts 12.
It has to be observed that, thanks to the perpetual clutching of the crown wheel 13 with the pinion 5, leaving the first moving member 1 fixed, and then the crown wheel 13, while the second moving member 7 is rotating, the rotation of the shafts 12 around the axis X-X causes, just because of the clutching of the pinions 5 with the crown wheel 13, in this case fixed, the corresponding rotation of the shafts 12 around their own axis Y-Y.
Then, the operating in cascade of the two moving members 1 and 7 of the propeller in
It has to be observed that, in the embodiment herein illustrated, the displacement extent of the members 1 and 7, that is their angular position, once their operating is finished, is determined by the geometry Z1 and Z2 of the toothed couplings (or toothing). These latter in fact allow such members 1 and 7 to move only by amounts determined by the dimensions (and then the number) of the corresponding teeth, being necessary a re-clutching of the moving members 1, 7 over the corresponding toothed couplings Z1 and Z2, at the conclusion of their operating.
The toothed couplings Z1 and Z2, defining in this case the possible displacements of the moving members 1 and 7, as well as the kinematic systems comprising the pinion 5 of each shaft 12, the crown wheel 13 of the moving member 1, the toothed coupling 2 between the moving member 7 and the case 6 respectively, as well as the case itself 6, constitute therefore the motion mode of such shafts 12 just when the moving members 1 and 7 are operated.
The peripheral crown wheel 13 of the first moving member 1, the pinions 5, the outer case 6 (maintained fixed), and the toothed coupling Z1 thereby constitute a first transmission kinematic system from the moving member 1 to the shafts 12 of the blades 11 and, similarly, the toothed coupling 2, the outer case 6, the crown wheel 13 itself (maintained fixed relatively to the hub 8 and engaged with the corresponding pinions 5) and the pinions 5, as well as the toothed coupling Z2, constitute a second transmission kinematic system of the motion from the moving member 7 to the shafts 12 of the blades 11.
It has to be noticed that, referring to the afore said second kinematic system for motion transmission, the outer case 6 relating to the hub 8, as well as the toothed coupling (or toothing) Z2, constitute the means for rotating the shafts 12 of the blades 11 around the propeller axis X-X, whereas the toothed crown wheel 13, with the pinions 5, constitute the means for rotating the shafts 12 around their axis Y-Y, when the rotation of the shafts 12 themselves around the afore said axis X-X occurs.
The afore said motion transmission means Z1, Z2, 5, 2, 6, 13 of the propeller herein described define, thanks to their geometry, at least two different laws of motion transmission relating the displacement of each moving member 1 and 7 to the displacement of the shafts 12 of the blades 11, so that the operating of the two moving members 1 and 7 may provide a synergic operating of the shafts 12, for example allowing a high regulating precision of the angular position of such shafts 12, and then of the propeller pitch. As mentioned yet, such laws of motion transmission are such functions relating reciprocally the displacement of a determined operating point of the corresponding moving member 1, 7 to the displacement of the corresponding shafts 12; functions that, in this case, are relating reciprocally the rotation around the propeller axis X-X of the moving members 1, 7, to the rotation of the shafts 12 around their own axis Y-Y.
More particularly, as it will be evident for a person skilled in the art, the geometry of the toothed couplings Z1 and Z2, as well as of the crown wheel and pinions composed by the crown wheel 13 and the pinions 5 of the shafts 12 of the blades 11, substantially determine the afore said at least two different laws of motion transmission from the moving members 1, 7 to the shafts 12.
Usually, and preferably, the tooth number in the toothed couplings Z1 and Z2 are different to distinguish the afore said at least two laws of motion transmission.
For example, the fulfillment of the two toothed couplings Z1, Z2 with a different number of teeth, independently from the circumference whereon the toothing is realized, concurs to determine two different laws of motion transmission from the moving members 1, 7 to the pinions 5 of the blades 11.
In other words, in the particular embodiment of the invention herein shown, the toothing Z1 and Z2 determine, according to the corresponding number of teeth, the minimal angular range of displacement of the moving members 1 and 7, and then the minimal angular rotation range of the blades 11 around their corresponding axes Y-Y, the multiples of which establish the whole angular displacement of the blades 11. Thereby, for example, if Z1 presents 22 teeth and Z2 presents 23 teeth, the corresponding annular moving members 1 and 7 could rotate by angles that are respectively multiples of 2π/22 radians and 2π/23 radians, such that, by operating in cascade such members 1 and 7 would be possible, by the kinematic systems above described, to provide the shaft 12 of each blade 11 as many as 22×23=506 different regulation possibilities.
Generally speaking, it has so to be observed that one of the advantages of the present invention is provided by the possibility of an extremely accurate regulation of the propeller pitch, that is of the angular displacement of the shafts 12 of the blades 11, without the need of using pinions and crown wheel having a higher number of teeth. In fact in the embodiments herein described, as it will be evident, making two regulations in cascade of which the first by a regulating device having a number N of teeth, and the second having a number M of teeth, it is possible to obtain M adjustments for each of the N previously determined positions, so obtaining a number of possible regulations of N×M in view of a number of teeth of N+M.
At last it has to be noticed that any other coupling between the moving members 1 and 7 and the hub 8 allowing the moving members 1, 7 to change from a constrained position to a de-constrained position from the same hub 8 and allowing, in the constrained position, the relative controlled displacement of such members 1, 7 relatively to the hub 8, falls anyway within the inventive conception of the present invention.
In the embodiment herein described the moving members 1 and 7 are separately operable, that is there is no law relating the mutual positions induced by the operator. However, such a moving members, according to alternative embodiments of the present invention, herein not shown, may be reciprocally constrained such that the operating of a member affects also the motion of the other moving member or the other moving members. Further, the fulfillment of a propeller provided with only one or more moving members falls in the inventive conception of the present invention, where each one of them, thanks to the kinematic systems of motion transmission, are provided with the possibility of changing the law of motion transmission between the blade and the moving member itself. Of such kinematic systems of motion transmission, at least one may be provided with gear wheel couplings. Further, in the embodiment herein described, the moving members 1, 7 are two, they have annular shape and have circular motion, but they may be only one too, they may be straight sliders or generally be provided with kinematic systems for transforming a translatory motion in a rotary motion, and vice versa.
Referring now to
This kind of solution, illustrated by way of example in
Similarly, the elastic connection means 22 elastically disconnects the moving member 7 from the outer case 6, elastically decoupling the two elements, by the toothed coupling 2 and the intermediate annular sleeve 17 interposition.
More in detail, the kinematic system for the motion transmission from the second moving member 7 to the shafts 12 of the blades 11 of the propeller in
In this way, once the propeller has been mounted, after the operator carried out the pitch regulation, the elastic connection means 22, thanks to its deformability, allows the outer case 6 to partially rotate around the moving member 7, thereby causing both a rotation of the blades 11 around the axis X-X of the hub 8, and the rotation of the shaft 12 of each blade 11 around its own axis Y-Y, thanks to the crown wheel 13 and the pinions 5, thereby causing a continuous automatic changing of the propeller pitch (as for example described in WO-A-2008/075187). Further, such an elastic decoupling by the connection means 22, will aid the possible jerk mitigation during the boat motion.
In short, as afore mentioned, such elastic connections, that can be one or more than one if present, exercise different functions, relating to their arrangement in the propeller.
As described yet, for example, both elastic connection means 21 and 22 of the propeller in
Alternatively, the elastic connection means 22 of the propeller in
Referring to what afore reported, and particularly to
The process for regulating the propeller pitch, according to an aspect of the present invention, may be executed rendering shiftable the outer portion of the propeller along the axis X-X, after at least the outer case 6, with the blades 11 and the regulating devices 1, 2, 5, 7, 13, Z1, Z2 of the angular position of the blades 11, that is of the propeller pitch, have been released from a stop, conveniently realized, having the purpose of impeding axial movements of the propeller by different clamps or blocks, as for example an engaging clutch, screw clutch, interfering clutch, by insertion of a pin, etc.
In
More in detail, in the specific embodiment of
The profile 45, in the embodiment of
More in general the coupling geometry between the ring 41 and the hub 8 may comprise one or more grooves 49 approximately displaced on planes perpendicular to the axis X-X of the drive shaft, so that, thanks to the engagement of the profile 45, the ring 41 is able to counter the translatory movements along the axis X-X of the same ring 41, and then of the outer case 6 of the propeller.
The clamping ring 41 may further present some toothing 48, 46, almost parallel to the axis X-X of the hub, integrally and rotationally coupling the afore said clamping ring 41 relatively to the hub 8 and the nut 43, in their turn advantageously provided with grooves.
Particularly, the nut 43 presents in fact some grooves 47 accommodating the toothing 46, and similarly the hub 8 may present similar grooves, not shown in the figure, to accommodate the toothing 48 of the clamping ring 41.
In this way, the clamping of the ring 41 integrally couples the nut 43, the hub 8, and the remaining propeller components.
Therefore, the propeller in
Thanks to the clamping type described, the forces acting on the outer case 6 of the propeller, along the axis X-X, that would aid a relative shift respect to the hub 8, are countered by the clamping ring 41 without directly acting on the clamping means of the hub 8 oh the drive shaft 10, comprising in this case the nut 43, but that can be composed of any other means adapted to hold the hub 8 to the drive shaft 10.
Further, the coupling of the toothing 46 with the complementary toothing 47, externally obtained on the nut 43, prevents the latter from rotating and unscrewing during the propeller operations. In fact, because of the integral constraint created between the ring 41 and the hub 8, the toothing 46 of the ring 41 necessarily rotates integrally with the hub 8 and then is opposing, thanks to its coupling with the toothing 47, to any relative rotation of the nut 43 relatively to the hub 8 and the shaft 10.
At last, the use of the clamping ring 41 entails an appreciable facilitation for the substitution of the afore said nut 43, in the assembling step, so that its type, the corresponding thread, as well as other its characteristics may be easily modified, without impacting the propeller assembling or its regulation.
After the propeller stop removal, for example composed of the ring 41, it is then possible to translate the case 6, with the blades 11 and the regulating device 1, 2, 5, 7, 13, Z1, Z2 relatively to the hub 8, to the point of de-constraining the moving members 1, 7 from the corresponding toothed couplings Z1 and Z2. At this point, it will be possible to locate the blades 11 in their “feathered” position, in order to establish a reference position starting from which it is possible to obtain an accurate regulation of the propeller.
After having determined which is the exact propeller pitch, that is the rotation angle of the blades 11 around their own axis Y-Y starting from the afore said “feathered” position of the same blades 11, it is possible, for example by a predetermined table, to determine which might be the corresponding clutching positions of the two moving members 1, 7 over the corresponding toothed couplings Z1 and Z2, and then the extent of their rotations around the axis X-X of the propeller.
At this point, a previously determined rotation of the first moving member 1 is carried out, until the latter will reach its desired clutching position with the toothing Z1. Such a rotation of the moving member 1 happens maintaining the outer case 6 fixed, so that to cause the rotation of the crown wheel 13 relatively to the latter, around the axis X-X, and then, by means of the pinion 5, to cause a first rotation of the shafts 12 of the blades 11 around their corresponding axis Y-Y.
Then, if it is necessary another regulation of the propeller pitch, not obtainable with the rotation only of the first moving member 1, it may be performed a rotation of the second moving member 7, to the point of reaching the latter too its calculated clutching position with the toothing Z2, which determines the relative rotation of the outer case 6, and of the blades 11, relatively to the axis X-X, and relatively to the crown wheel 13, maintained fixed and engaged with the pinion 5, so that to provide one more angular rotation, around the corresponding axes Y-Y, the shafts 12 of the blades 11. Such a further angular rotation, because of the different laws of motion transferring of the first kinematic system Z1, 5, 13 and the second kinematic system Z2, 2, 6, 5, 13, will cause angular changes in the position of every shaft 12 of the blades 11 around its own axis Y-Y, different from these previously obtained operating the first moving member 1, so that it is possible to obtain an extremely exact and accurate regulation of the propeller pitch.
As an alternative, in a further possible embodiment of the propeller according to the present invention shown in
More in details, two graduate scales (101 and 102), respectively for the first and the second moving members (1, 7) are stamped, or attached, on the external propeller surface.
Each scale (101 and 102) is provided with a fixed reference point (103, 104) from which it is possible to set the angle of incidence that will be reached by the blades (11) after the rotation of the first and the second moving member (1, 7) both in the clockwise or the anticlockwise direction.
In this way, the user can regulate the propeller in a very simple manner by rotating the moving members (1, 7) of the desired value directly visible on the scales (101 and 102) without using the aforementioned table.
It has to be observed that, although it has been described the initial operating of the first moving member 1 and then of the corresponding kinematic system Z1, 5, 13 and then the operating in cascade of the second moving member 7 with the corresponding kinematic system Z2, 2, 6, 5, 13, it is obviously possible to obtain a similar propeller pitch inverting the afore described operation sequence.
The subsequent shift of the members 1, 7 of the blades 11 and the outer case 6 to the point of obtaining the re-clutching of the moving members 1, 7 on the corresponding toothing Z1, Z2 of the hub 8, will complete the manual regulation step of the pitch.
Such rotations and shifts having been executed, which, thanks for example to the different number of teeth of the toothing Z1 and Z2, allow to obtain an efficient and accurate regulation of the propeller pitch without the need of long regulating operations, the propeller is completely re-assembled, inserting again the afore said stop to prevent the shift along the axis X-X of the various components of the propeller itself.
The embodiment schematically illustrated in
The propeller in
However, differently from the propeller of
More in detail, the first moving member 1, composed of an annular body coaxial to the hub 8, is integral with, not permanently, the same hub 8 thanks to the toothing Z1, for example provided with M teeth, and it is connected to the shafts 12 of the blades 11 thanks to a first kinematic system of motion transmission Z1, 15, 13, 5. Such a first kinematic system comprises, in addition to the toothing Z1, a ring 15, that is rotationally integral around the axis X-X with the first moving member 1, being coaxially mounted to the hub, just rotatably around the afore said axis X-X, and it is further peripherally provided with a toothed annular crown wheel 13, that is always engaged with the pinions 5 of the shafts 12.
The shape of the toothing Z1 is such that a shift of the first moving member 1, particularly along the axis X-X in direction of the prow, allows to decouple such a member 1 from the hub 8, without for this reason decoupling the two components 1 and 15. For countering such a shift and assuring a constant and permanent coupling of the member 1 with the hub 8, in absence of outer forces directly or indirectly exercised by the operator (by a servo-control), a torsion spring 18 is provided, opposing to the afore said shift along the axis X-X in direction of the prow.
The second moving member 7, 17 of the device for regulating the propeller pitch of
Such a second kinematic system comprises, in addition to the toothing
Z2, an outer case 6 of the propeller, a toothed coupling 2, rendering rotationally integral the case 6 itself with the second moving member, as well as the pinions 5 of the blades 11 and the crown wheel 13 (always engaged with the pinions 5 and fixed, during the regulation effected by such a second moving member 7, 17). It has to be observed that the toothed coupling 2 is dimensioned such that the outer case 6 and the second moving member 7, 17 are always coupled, also when the moving member 7, 17 is shifted relatively to the hub 8 along a direction parallel with the axis X-X of the propeller, in the stern direction.
Further, the toothing Z2 is shaped such that the shift of the moving member 7, 17 relatively to the hub 8 in the stern direction causes the moving member decoupling from the same toothing Z2.
For countering such a shift and assuring a constant and permanent coupling of the moving member 7, 17 and the toothing Z2 a torsion spring 19 is provided, opposing to the shift realized in the regulating step of the propeller pitch.
The second moving member 7, 17 of the propeller of
It has to be noticed that the means of elastic radial connection 22, as before better described, has both the function of mitigating possible impacts (jerks) which the propeller may be subjected to during the motion, and allowing an automatic regulation of the propeller pitch, during the boat motion.
Further, it has likewise to be observed that the toothing Z2 obtained on the hub 8 and the annular member 7 is specifically shaped to maintain the coupling of the member 7 with the hub 8 in a predetermined position assembly only, which are obtained or missed after a shifting along a direction parallel to the axis X-X of the same member 7.
For carrying out the manual regulation of the propeller pitch in
To carry out the propeller pitch regulation operating the second moving member 7, 17 it is necessary to shift the moving member 7, 17 in the stern direction with a sufficient force to overcome the opposite one by the torsion spring 19. When the afore said translation of the moving member 7, 17 in the stern direction has been obtained for a sufficient length, the decoupling of such a member 7, 17 from the toothing Z2 is obtained. In this way, once such a decoupling has been obtained, it is possible to rotate the moving member 7, 17, except for elastic deformations by the elastic connection means 22, around the axis X-X of the hub 8. Being the moving member 7, 17 constrained (by the toothing 2) to rotate integrally to the outer case 6, which makes to rotate the shifts 12 around the axis X-X of the hub 8, the rotation of the moving member 7, 17 further entails the rotation around the axis X-X of the hub 12 of the blade 11, that is engaged to the crown wheel 13 by the pinions 5. In consequence, a rotation of the moving member 17 entails a changing of the propeller pitch too.
The implementation in cascade of the two moving members 1 and 7, 17, as afore described referring to the propellers in
| Number | Date | Country | Kind |
|---|---|---|---|
| MI2009A000719 | Apr 2009 | IT | national |
This application claims the benefit of priority from Italian Patent Application No. IT/MI2009A000719, filed Apr. 28, 2009 and PCT Application No. PCT/IT2009/000154, filed Apr. 8, 2009. This application is also a continuation-in-part of PCT/IT2009/000154. The contents of each application are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/IT2009/000154 | Apr 2009 | US |
| Child | 12755141 | US |
