EP0389979A2 - Z-type stearable balanced power transmission - Google Patents

Abstract

The power transmission system, especially for transmitting power through gears and shafts in a Z-formation between a power unit and an output element (30) such as a propeller, consists of housings (1,2) containing gears linked to the output element and power unit, and coaxial and contra-rotating shafts between them. The shafts are connected to bevel gear systems (21-28) inside the two housings, forming variable ratio gears and clutches. The systemm can be applied to both ships and aircraft, and can also be employed for wind-powered generators.

Description

The present invention relates to a "Z" type power transmission used in particular, but not exclusively, in the field of naval propulsion. It is associated with a motor located inside the hull and transmits power to the horizontal propeller shaft which is placed in a position such that the propeller does not interfere with the boundary or wake layer. The most used type of transmission is the one that comes out of the stern mirror and, in nautical jargon, it is called "interior transmission - outboard" or "rear leg".

Power transmissions of the "Z" type with transmission outside the hull, marketed to date, guide the boat by means of the orientation of the axis of the propeller relative to to the longitudinal axis of the boat with the disadvantage that this orientation has a maximum angle of 30 ° to the right and 30 ° to the left and that the reversal of the direction of travel is achieved by reversing the direction of rotation of the 'propeller. These conventional transmissions also have the disadvantage that the lifting of the foot in a vertical plane is limited by the presence on the transmission of a double universal joint and this lifting can reach a maximum value of approximately 50 °.

As is known, for maneuvering in limited waters, there is a need to be able to orient the propeller in any azimuth direction, so as to allow maximum exploitation of the maneuvering capacities of the boat. We also feel the need to be able to completely raise the rear leg in a vertical plane for inspection and / or to adjust this lifting according to the desired orientation of the thrust, which translates, for planing hulls, by a variation of the plate.

The objective of being able to direct the propulsive thrust in any direction of the horizontal plane, independently of the uplift, for what we know from reading published patents, has been achieved until now by complicated mechanisms starting from a torsional moment balancing system or by a normal "Z" transmission and by servo-assisted guide mechanisms, slow and strictly irreversible.

Torsion balancing systems are described in the following patents: US 2,755,765, US 3,094,967, GB 975,436, DE 1,165,442, US 3,486,478, US 3,750,616, US 3,851,614, and US 4,619,158.

Systems with a servo-assisted drive mechanism are described in the following patents: US 2,499,339, US 2,532,470, US 3,217,688, US 3,452,703, US 3,554,155, US 3,707,939, US 3,769,930 , US 3,795,219, US 4,074,652, US 4,516,940 and US 4,634,389.

The total lifting of the foot has been dealt with in US Pat. No. 4,516,940 and the removable nature in US Patent 4,634,389. However, in these cases, the foot is separated and the power transmission is interrupted.

The object of the present invention is to provide a power transmission in "Z" of the type mentioned above with a device shaped so as to allow variations in azimuthal orientation of 360 ° from the axis of the propeller or propellers. and that, of course, keeping the power transmission running.

Another object of the invention consists in shaping this transmission so as to allow lifting in a vertical plane, by rotation of the body which constitutes the foot, which can reach 180 ° with respect to the normal position while maintaining, in this case also , the power transmission on.

These and other objects of the invention will emerge from reading the description and the claims which follow, drawing attention to the fact that the present power transmission finds, in particular, a valid use in the nautical field, but that it can also find a valid use in other fields such as, for example, the aeronautical field or the field of the exploitation of wind energy.

• un premier corps associé à un organe actif,
• un second corps associé à un premier arbre de transmission d'énergie audit organe actif,
• un couple d'arbres coaxiaux et contra-rotatifs interposés entre les premier et second corps,
• des moyens contenus dans le second corps pour la rotation du premier corps autour d'un axe vertical confondu avec celui du couple d'arbres coaxiaux et contra-rotatifs, et elle est essentiellement caractérisée par le fait qu'elle comprend en outre :
• des moyens interposés entre le premier arbre et l'organe actif aptes à permettre la rotation relative entre le premier corps et le second corps en maintenant la transmission de puissance en marche.

The power transmission according to the invention is of the type comprising:

• a first body associated with an active organ,
• a second body associated with a first energy transmission shaft to said active organ,
• a pair of coaxial and counter-rotating shafts interposed between the first and second bodies,
• means contained in the second body for the rotation of the first body about a vertical axis coincident with that of the pair of coaxial and counter-rotating shafts, and it is essentially characterized in that it further comprises:
• means interposed between the first shaft and the active member capable of allowing relative rotation between the first body and the second body while keeping the power transmission running.

According to another characteristic, the drive shaft of the energy is coaxial and opposite a second shaft representative of the torque or moment of torsion applied to the means for the rotation of the first body.

• la figure 1 illustre schématiquement une transmission conventionelle de puissance du type en "Z" appliquée à un propulseur nautique à l'exclusion du système de guidage,
• la figure 2 illustre schématiquement une transmission de puissance de type en "Z" supposée appliquée à un propulseur nautique,
• la figure 3 illustre schématiquement une transmission de puissance du type en "Z", avec un système de guidage, appliquée à un propulseur nautique selon une forme d'exécution de l'invention,
• les figures 4 à 15 illustrent chacune schématiquement une autre forme d'exécution selon l'invention de la transmission de puissance du type en "Z", avec systeme de guidage,
• la figure 16 illustre de manière indicative l'application d'une transmission de puissance selon les figures 3-15 au domaine de l'exploitation de l'énergie éolienne,
• la figure 17 illustre de manière indicative l'application d'une transmission de puissance selon les figures 3-15 au domaine aéronautique,
• la figure 18 représente une réalisation pratique de la transmission de puissance conforme au schéma de la figure 5 selon la section G-G de la figure 19,
• la figure 19 est une section selon H-H de la figure 18,
• la figure 20 représente, en section, une réalisation pratique d'une transmission de puissance conforme au schéma de la figure 7,
• la figure 21 représente, en section, une réalisation pratique d'une transmission de puissance conforme au schéma de la figure 11,
• la figure 22 représente schématiquement comment deux transmission de puissance selon la figure 21 sont appliquées à une coque du type planant.

The invention is illustrated, by way of nonlimiting example, by the appended figures in which:

• FIG. 1 schematically illustrates a conventional power transmission of the "Z" type applied to a nautical propellant excluding the guidance system,
• FIG. 2 schematically illustrates a power transmission of the "Z" type assumed to be applied to a nautical thruster,
• FIG. 3 schematically illustrates a power transmission of the "Z" type, with a guidance system, applied to a nautical thruster according to an embodiment of the invention,
• FIGS. 4 to 15 each schematically illustrate another embodiment according to the invention of the power transmission of the "Z" type, with guidance system,
• FIG. 16 illustrates in an indicative manner the application of a power transmission according to FIGS. 3-15 to the field of the exploitation of wind energy,
• FIG. 17 illustrates in an indicative manner the application of a power transmission according to FIGS. 3-15 in the aeronautical field,
• FIG. 18 represents a practical embodiment of the power transmission in accordance with the diagram of FIG. 5 according to the section GG of FIG. 19,
• FIG. 19 is a section along HH of FIG. 18,
• FIG. 20 represents, in section, a practical embodiment of a power transmission in accordance with the diagram of FIG. 7,
• FIG. 21 represents, in section, a practical embodiment of a power transmission in accordance with the diagram of FIG. 11,
• FIG. 22 schematically represents how two power transmissions according to FIG. 21 are applied to a hull of the planing type.

If we consider the traditional transmission in "Z", excluding the driving system, the diagram is that of figure 1.

To give the propeller axis the possibility of orienting itself completely, it is necessary to cut the casing containing the vertical drive shaft, according to a plane shown in Figure 1 in AA and using a mechanism which gives the possibility of controlling the rotation of the foot 1 relative to the upper part or box 2.

This mechanism, the operation of which ensures the guiding of the boat or of the ship, must withstand the reaction to the torque or moment of torsion transmitted by the inner shaft 3, a reaction which passes through the casing in the section under consideration.

The principle that we adopt consists in canceling the above reaction to ensure that the mechanism in question can be activated by forces of modest value. Because in this case, although cutting off the casing, the reaction missing in it, the foot 1 remains stable with the power transmission on. By transmitting the movement, through section A-A in FIG. 1, by means of two counter-rotating coaxial shafts with equal and opposite torques or moments, the resulting reaction, absorbed by the casing, is zero. This condition is achieved with the diagram in FIG. 2 where the bevel gears 4 and 5 are identical just like the gears 6 and 7.

Considering stopped this type of transmission, we note that it is not possible to rotate the foot 1 around the common axis, relative to the upper part 2 because, since a relative rotation of the trees contra -rotating 8 inside and 9 outside must be carried out, the arrangement of the shafts and gears united between them prevents it.

To clarify, by simply referring to FIG. 1, the "Z" conformation of the transmission is defined by the drive shaft 10, the vertical shaft 3 and the propeller shaft 11.

The present invention, still starting from the diagram in FIG. 2 (counter-rotating shafts, therefore cancellation of the reaction), we consider four fundamental ways of rotating the foot 1, not only along the vertical axis but also and simultaneously, if desired, along an upper horizontal axis of rotation about which it is desired to carry out the lifting in a vertical plane of the assembly composed by the foot 1 and by the upper part or box 2. Each of these four ways is represented diagrammatically in the figures 3, 4, 5 and 6 as well as some variants of the way of Figure 5 in Figures 7-10 and some variants of the way of Figure 6 in Figures 11-15.

As it is possible to notice, all of these diagrams have in common, as a fundamental and exclusive principle which will be better understood later, the fact that the torque or guiding torque enters the upper box 2 by means of a shaft coaxial and opposite to that which transmits the propulsion energy, so that, by allowing the box 2 to rotate around said horizontal axis, the two input transmissions are maintained with continuity inside the same upper box. Consequently, all the internal mechanisms are capable of respecting these conditions.

FIG. 3 relates to the case where, along each of the two counter-rotating shafts 8 and 9, freewheel seals 12 and 13 are interposed.

By doing so, with the power transmission running, the foot 1 maintains its position stably, unless a moment or torque tending to rotate it occurs. The value of this moment must be equal to or greater than that transmitted, at this time, by one of the shafts: this moment is transmitted to foot 1 through the gear train 14, 15, 16 and 17 and the corresponding shafts among which, it should be observed, the tree 18 input representative of this moment and which is also that of guiding. The gear 17 is integral with the foot 1. In this solution, the interposition of a friction clutch on the motor shaft 10 is suitable and it is advisable to use an auxiliary rudder for small variations in the route. The operation of the foot, in this case, should preferably occur when the motor transmits powers of modest value.

The choice of this type of transmission is intended, in principle, for medium-sized ships such as ferry boats and tugs and for sailing boats with an auxiliary engine.

FIG. 4 relates to the case where, along each of the two counter-rotating shafts 8 and 9, a friction clutch 19 and 20 is interposed, respectively.

This case is considered, according to the knowledge of the inventor, in the patents: GB 975,436, DE 1,165,442 and US 3,486,478.

However, there has apparently been no corresponding marketing, no doubt due to the difficulty of the practical execution of the automatic device for controlling the two clutches.

The clutches 19 and 20 are actuated, one at a time, automatically, before each control tending to rotate the foot 1, by a mechanism integrated in the guide system which is composed of the gears 14, 15, 16, 17 and by their trees. The controlled clutch, that is to say disconnected, is that concerning the shaft which, for this rotation, is requested to slide.

An auxiliary device, not shown in this diagram, makes it possible to control the simultaneous detachment of the two clutches.

It is advisable to use an auxiliary rudder for small variations in the course.

The choice of this type of transmission is provided in principle for ferries and tugs as well as for sailing boats with an auxiliary engine.

Figures 5 and 7 (the lower part of Figure 7 is as in Figure 5) relate to the case where, between the drive shaft 10 and the two counter-rotating shafts 8, 9 of the foot, there is interposition of a differential 21 followed by two gear trains 22 with 23 and 24 with 25 with equal ratio, the gears 23 and 25 being respectively associated with the shafts 8 and 9.

In this way the motor torque is distributed to the same extent, by the presence of the differential 21, on the two counter-rotating shafts 8, 9 in movement, even if one of them performs a rotation greater than that of the other . The conditions for the free rotation of the foot with the power transmission on are thus fulfilled.

The presence of the differential and considered in US Pat. No. 3,094,967 already cited where, however, in order for it to be able to perform its function, it is necessary to interpose an inverter between the differential and the foot, indicated by 22-25 in the figure. 1 of this patent.

According to the present invention, on the contrary, the particular arrangement of the members as a whole makes it possible to eliminate this inverter and to carry out a lifting of the foot in a vertical plane in addition, naturally, to the orientation of the axis of the propeller in a horizontal plane.

In FIG. 5, the movement is transmitted to the satellites of the differential by means of a cross 26 secured to the shaft 10 while in FIG. 7 the movement is transmitted by means of a bell 27 and in both cases the planetary ones 28 are each secured to a bevel gear which transmits the movement, each by means of its correspondent, to the vertical coaxial shafts 8, 9.

The mechanism of Figure 5 is more compact, while that of Figure 7 is simpler in its construction.

In addition to the mechanisms shown diagrammatically in FIGS. 5 and 7, the differential can be mounted near the propeller according to the diagrams in FIGS. 8, 9 and 10, the upper parts of which are as in FIG. 6.

In FIG. 8, the movement of the two coaxial shafts 8, 9 is transmitted by each, split, on two opposite counter-rotating propellers 30 and one of the two (the central shaft 8 in the case of FIG. 8) the transmits through a differential 29.

The same function can have a differential connected to the outer shaft and the arrangements of the gears in the box of foot 1 can be different.

In the case of FIG. 8, the torsional moment transmitted by the differential 29 arranged near the propeller is half that transmitted by the differential 21 provided in the upper part or box 2 of the diagrams in FIGS. 5 and 7.

In FIG. 9, the differential 31 is disposed between the final bevel gears 32, 33 and the shaft 11 of the propeller at a cross member 34 which carries the satellites 31 'of the differential 31.

In FIG. 10, the differential 35 is placed between the two horizontal coaxial shafts 36, rotating in the same direction, and the propeller 30. The studs or trunnions 37 on which the satellites rotate are integral with the hub 30 'of the propeller.

For all these cases of FIGS. 5, 7, 8, 9 and 10, the interposition of a friction clutch after the engine is necessary.

FIG. 6 relates to the case where, in the box 38 of foot 1, each of the counter-rotating shafts 8, 9 transmits, through a bevel gear train, its torsional moment to its own individual propeller shaft 11 'and 11 "which necessarily in the diagram are offset. This is how the foot 1 is free to rotate and that the current system of gears transmits to it the command for its rotation. In this case, a condition is imposed as regards concerns the considerations expressed previously, it is that the moments of torsion transmitted by the two counter-rotating shafts 8 and 9 are equal so that the reaction to these moments existing on the foot 1 is zero. condition, the more the difference between the powers absorbed by the two propellers tends to zero.

FIGS. 11, 12, 13, 14 and 15, the upper parts of which are identical to that of FIG. 6, schematize mechanisms based on the same principle as in FIG. 6.

In FIG. 11, the movement arrives at two coaxial, adjacent and counter-rotating propellers which have been widely adopted for a long time.

Figures 12 and 15 show two mechanisms which transmit the movement to two coaxial propellers 30, adjacent and rotating in the same direction. The hydrodynamic characteristics of this pair of propellers, although predictable, are not known.

In FIGS. 13 and 14 the propellers are arranged as in FIG. 6, but they are coaxial: in FIG. 13 they are counter-rotating, while in FIG. 14 they rotate in the same direction.

For all these mechanisms shown diagrammatically in the cases of FIGS. 6, 11, 12, 13, 14 and 15, which are relatively simple, the interposition of a friction clutch after the engine is necessary.

For the types of transmission shown diagrammatically in FIGS. 5 to 15, provision is made for the generalization of use.

In addition to marine applications, the invention in all of these embodiments can also be applied to other sectors, such as the wind and / or aeronautical sector.

In the wind power sector, if a wind-driven propeller is to be connected to an electric generator or other stationary machine (Figure 16) and if the propeller axis 39 in the wind direction, by applying one of the mechanisms shown above to the power transmission, it is possible to control the orientation of the propeller only with the force of the oriented blade 40 by the wind itself or by an automatic control of small power.

In aeronautics, in convertible aircraft (Figure 17), we need to modify, with the engine fixed and with power transmission running, the orientation of the axis of the propeller (or propellers) from the vertical position of takeoff to that of horizontal flight. By applying one of the transmissions mentioned above, the requested result is obtained with a low power command.

The invention is described below with the aid of three embodiments which relate respectively to the cases of FIGS. 5, 7 and 11.

The production of a transmission according to the diagram in FIG. 5 is illustrated by FIGS. 18 and 19.

The drive shaft 41, after a friction clutch and an elastic seal 42, leaves the stern mirror 43 and enters the box 44 where, by means of a bevel torque 45, 46, it drives the shaft 47 (which in practice corresponds to the motor shaft 10 shown diagrammatically in FIGS. 3-15) which carries, in orthogonal arrangement, the four studs or trunnions 48 on which are mounted four conical satellites 49 engaged all together with two bevel planetary gears 50: this coupling constitutes the differential (indicated at 21 in FIG. 5).

The bevel gears 50 are integral with each of the gears 51 and 52 which transmit the movement, with an identical ratio, to the counter-rotating vertical shafts 53 and 54 by means of their couples or bevel gears 55 and 56.

A current mechanism for returning to the counter-rotating propellers 57 and 58, the operation of which is immediately understood, completes the power transmission.

The control member is constituted by the transmission comprising the shaft 59 '(corresponding to the pipe shaft shown diagrammatically at 19 in FIGS. 3-15) and the gears 59, 60, 61 and 62, the final gear 62 being integral, via the hollow shaft 63, of the foot 64 containing the propeller shafts.

A hydraulic cylinder 65, by rotating the part 66, and therefore also the foot 64 around the sockets 67 and 68 coaxial with the shaft 47 and the shaft 59 ', determines the angle of lifting of the axes of the propellers in the vertical plane.

A simple device 69 prevents the lifting of the foot 64 when the propulsion thrust is directed towards the stern while it does not obstruct it when, as in the case of an impact impact, the foot is pushed to lift .

By means of the traction of a steel cable 70, which cooperates with a grooved wheel 71, it is possible to carry out the total lifting of the assembly 64, 66, for example for the inspection and / or cleaning of the propeller.

The embodiment of a transmission according to the diagram in FIG. 7 is illustrated in FIG. 20, where the lower part is identical to that of FIGS. 18 and 19.

The driving energy arrives at the bell 72 by means of a bevel gear 73 integral with the latter. The bell 72 carries studs or journals 74 on which the satellites 75 rotate which are simultaneously engaged with the sun gear 76 secured to the shaft 77 and with the sun gear 78 forming a single block with the bevel gear 79.

The shaft 77 transmits the movement of the planet wheel to the bevel gear 80. Thus the motive power arrives split, through the differential, to the counter-rotating vertical shafts 81 inside and 82 outside.

The rest of the mechanism is identical to that illustrated in the previous figures 18 and 19.

It is clear that, in this case too, there is coaxiality between the motor shafts 77 and driven 59 'and therefore the possibility also of rotation of the whole assembly around their common axis for the lifting of the assembly.

The embodiment of a transmission according to the diagram in FIG. 11 is illustrated in FIG. 21 applied to a hull (planing) prepared for the application of two motors and two transmissions in "Z" according to the diagram in FIG. 22 which represents said shell seen from above.

Note the particular shape of the stern to allow the exit outside of the transmissions through the vertical longitudinal walls 83 and 84 (the one on the right 84 is also shown in Figure 21). The pipe controls, gathered under table 85, pass through the vertical transverse walls 86, 87.

Referring in particular to FIG. 21, the engine torque or moment of torque arrives at the shaft 88 ′ and therefore at the bevel gear 88 through a friction clutch 89 and an elastic seal 90 and is distributed through the gears 91 and 92, to the counter-rotating coaxial shafts 93 and 94. These transmit the movement intended for the counter-rotating propellers 95 and 96 located in the foot 97 (which is shown here rotated 90 ° relative to the direction normal), each for its own account, by means of two bevel gear trains 98 and 99, with two coaxial shafts 100 inside and 101 outside corresponding respectively to 11 'and 11 "of the diagram in FIG. 11.

The propeller 96 is of variable pitch (conventional) with adjustment from the outside so as to be able to make the torsional moments transmitted by the two vertical counter-rotating shafts identical.

In this case also, the whole assembly rotates around the axis of the motor shaft by means of the sockets 102 and 103 so as to vary the attitude or to raise the foot by means of the cable 104 and, as in all in the aforementioned cases, there is coaxiality between the drive shaft 88 'and the shaft 105 representative of the torque or torque of driving. The control of the pipe is transmitted, by means of the chain pinion 106 and the aforesaid shaft 105, to the internal gears, as described for FIG. 18.

Claims (11)

"Z" type power transmission including: - a first body (1) associated with an active member (30); - a second body (2) associated with a first shaft (10) for transmitting energy to said active member (30); - a pair of coaxial and counter-rotating shafts (8, 9) interposed between said first (1) and second body (2); - Means (14,15,16,17,18) contained in said second body (2) for the rotation of said first body (1) about a vertical axis coincident with that of the pair of coaxial and counter-rotating shafts ;
characterized by the fact that it further comprises means (12,13,19,20,21,29,31,35) interposed between said first shaft (10) and said active member (30), capable of allowing rotation relative between said first body (1) and said second body (2) while keeping the power transmission on. Transmission according to claim 1, characterized in that said energy transmission shaft (10) is coaxial and opposite a second shaft (18) representative of the torsional moment applied to the above means (14-18) for the rotation of the aforesaid first body (1). Transmission according to claim 1, characterized in that said means interposed between said first shaft (10) and said active member (30) are composed of freewheel seals (12,13) each associated respectively with one of the above two counter-rotating coaxial shafts. Transmission according to claim 1, characterized in that the said means interposed between the said first shaft (10) and the said active member (30) are composed of a differential gear system (21) comprising a planet carrier spider (26) connected in the above first tree (10), the planetary (28) of the differential being freely rotatable around said first shaft and each transmitting its movement, through a gear train (22,23-24,25), to one of the two vertical counter-rotating shafts (8,9). Transmission according to claim 1, characterized in that said means interposed between said first shaft (10) and said active member (30) are composed of a differential gear system (21) comprising: a bell (27) carrying the satellites and connected to the aforesaid first shaft (10), a central shaft (27 ') pivoted to said bell (27) carrying a first sun gear (28) connected, via said central shaft (27') and a gear ( 22), to a gear (23) driving in one direction said inner shaft (8) and a second sun gear (28) of the above differential being connected, by means of a gear (24) integral with itself, to a gear (25) driving said outer shaft (9) in another direction. Transmission according to Claim 1, characterized in that one of the said counter-rotating shafts (8, 9) transmits its movement simultaneously to two opposite and counter-rotating active members (30), while the other shaft transmits it to the same active organs (30) through a differential (29). Transmission according to claim 1, characterized in that the counter-rotating shafts (8,9) transmit their movement to the active member (30) through a differential (31), the axis (11) of said active member ( 30) carrying a spider (34) on which the satellites (31 ') of said differential rotate. Transmission according to claim 1, characterized in that the counter-rotating shafts (8,9) each transmit their movement to two coaxial shafts (36) to the axis of the active member (30), each of said shafts (36), on the side of a hub (30 '), being integral with a sun gear of a differential (35) including the pivots (37) satellites are integral with said hub (30 '). Transmission according to claim 1, characterized in that each of the two counter-rotating shafts (8, 9) actuates its active member (30), both adjacent and opposite, both counter-rotating and rotating in the same direction. Transmission according to any one of the preceding claims, characterized in that it is used in the aeronautical field, in particular for convertible devices. Transmission according to any one of the preceding claims, characterized in that it is used in the field of the exploitation of wind energy.

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