EP0869056A1

EP0869056A1 - Propeller tail for boats

Info

Publication number: EP0869056A1
Application number: EP97919413A
Authority: EP
Inventors: Angel Romero Lago
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-04-29
Filing date: 1997-04-28
Publication date: 1998-10-07
Also published as: WO1997041029A1; ES2134097B1; ES2134097A1

Abstract

The propeller tail is intended to be applied to yachts, fishing boats and the like, and is designed to be mounted either internally or externally with respect to the boat itself. The propeller tail structure is based on two truncated groups (11 and 12), the first truncated group being associated to a crown (9) which receives the attack of a gear which moves through the corresponding motor so that the upper truncated group (11) transmits, by means of an axial connection shaft (13), the motion to the lowering truncated group (12) in order to transmit by means of another crown (23) the rotation to the shaft (21) on which is mounted the corresponding propeller (6), all of which being complemented by a rotation system based on a hydraulic rack (28) which is immersed in oil and which is in mesh with a crown (27) so that the final reduction selected from the motor-shift unit to the propeller (6) is achieved through the truncated groups (11 and 12).

Description

OBJECT OF THE INVENTION

The invention refers to a propeller tail for boats to be mainly applied to yachts, coastal fishing boats and the like, the tail itself being structured and made up in such a way that it may be mounted either internally or externally, with respect to the boat itself.

The propeller tail intends that the boat to which it is applied may have a greater manoeuverability and reach a higher cruising speed, having an effect not only on a higher economic use of the boat itself, but also on the possibility of riding out bad sea conditions with greater safety.

BACKGROUND OF THE INVENTION

Propeller tails manufactured at present in the recreational scope range up to medium length or are designed for trailing in ferry boats or dredges, where cruising speed does not have priority.

So, tails used for recreational boats include a generally low quality, aluminium-alloy-casing, with integrated gearing which occupies a big volume, and may be mounted externally with respect to the boat.

Furthermore, the steering of the boat is done by turning the whole body of the tail by means of ball-and-socket joints, and that requires the fitting of rubber seals for the watertightness between the tail and the boat, in such a way that sea water quickly causes wear and tear to the said pice of rubber and enters the boat, causing premature mechanical perishing.

For the aforementioned reason, a transmission with crossheads is required for joining the engine to the tail; as time goes by, this transmission, due to play and to the maladjustment of the crosshead dowel itself, caused by lack of lubrication, causes vibrations which give raise to high noise.

The fact must also be emphasised that, in conventional propeller tails, sea water for mechanical cooling flows through the inner part of the casing, depositing dirt and contributing not only to its rapid wear, but also to the diminishing of its mechanical cooling capacity.

Another drawback shown by conventional tails is that their radius of rotation is 70° as a maximum and propellers are made of aluminium, being less reliable from the point of view of their resistance, not being able to surpass a 508 mm. diameter.

Another characteristic of conventional propeller tails is that they show an almost null flap surface, so that if these elements are not incorporated in the propeller tail, the boat stern lowers visibly when accelerating.

In brief the recreational tails thus far known offer a mechanical and structural fragility and those manufacturated for dredges and ferry boats may be applied to neither yachts nor fishing vessels, due to their different needs.

On the other hand, independently of fishing vessels which are usually equipped with outboard engines, all other boats mount tail shafts, the same occurring with yachts, so that the aforementioned tail shaft implies a low speed when working with water disturbed by the hull, as well as lower manoeuvring capacity and greater space occupation, having an effect in the bailing of holds in fishing vessels, whereas in yachts they are generally under-used, reaching sometimes up to 50% of its overall surface, basically in those of short length.

If we add to the foregoing the fact that sometimes the tail shaft is not parallel to the water surface, but declined up to 12° or more for the purpose of putting the propeller as far back as possible and gaining useful space. This causes the propeller not to use all its power to move the boat, in such a way that in some cases the shipyard is obliged to build hulls only keeled from the head to the exit of the tail shaft, in order to achieve the tail shaft parallel to water, and this causes the boat to pitch in bad weather conditions, requiring sometimes the fitting of additional flaps.

DESCRIPTION OF THE INVENTION

The propeller tail which is proposed has been conceived to the end of solving completely the problems previously stated, showing a great mechanical simplicity, with an oversize in order to avoid possible failure and to withstand the most adverse working conditions, also showing the peculiarity that the tail may be mounted either inside the boat or hanging above the upper stern, this is to say, externally. To all that precedes is added the characteristic that the group engine-gear-tail makes up a compact unit which is assembled over a metallic framework, without any kind of transmission, occupying therefore a minimum space and ruling out sometimes the engineroom. If we add that the casing is made of bronze and manganese, guaranteeing the rigidity of the mechanical drive and the sea corrosion resistance, it is obvious that the propeller tail of the invention is highly advantageous in comparison with those presently known.

More precisely, the propeller tail of the invention comprises two truncated groups linked to each other by means of a central connection shaft, in such a way that one of the groups, through a crown, receives the moving power coming from the corresponding engine, whereas the other, through another crown, transmits movement to the shaft carrying the propeller, the unit of the double truncated group with their shaft, pinions and crown being immersed in oil and placed logically in a general casing, with races, O- rings joints, adjusting nuts, etc.

On the basis of the two truncated groups the final reduction chosen between the engine and the propeller is achieved, this taking place by means of these truncated groups, and not with the gear associated to the engine, as it is traditional.

The fact must be also emphasise that the central connection shaft which links the two truncated groups is fragile, so that it can break in the event of collision with stones or logs, and protecting, therefore, the rest of the mechanism.

Another important particular of the tail of the invention is the use of the pump, on the basis of which a flow of continuous oil may be created from one end of the tail itself, to the other, achieving efficient cooling and a perfect thermal balance, the pump being based on two single pieces with no contact between them, so there would neither be wear nor possible failure, the pieces or components of which are an upper cover fixed to the general casing of the tail and a shaft carrying the crown which receives the rotation power coming from the engine, all of that with the peculiarity that, in order to achieve a higher performance and efficiency, the oil must be drawn in by the upper part of the aforementioned shaft carrying the crown and expelled by the corresponding attack pinion which is the the means of interconnection between the lower end of the shaft and the lower truncated group, through which the shaft of the propeller itself is pushed.

The stern also has a hydraulic steering system integrated by an hydraulic rotation rack in mesh with the corresponding toothed crown.

Structurally the said propeller tail, according to the preferred way of making it, is intended to be mounted internally, including the corresponding nozzle, or mounted externally, in which case it will be fixed, by means of a metallic support, to the respective boat stern, incorporating. in this case flaps of big surface, with the advantages that that implies.

Therefore, among the advantages that the propeller tail offers, the following may be mentioned, as those most important:

Possibility of being mounted either internally or externally.
Internal steering by means of a hydraulic rack, this avoids the usage of rubber seals for watertightness.
Compact mounting without need of transmission.
Casing made of bronze and manganese, with the high mechanical resistance that this implies, being also watertight to the sea water and immersed internally in oil.
Radius of rotation of 90° to 180^a
Diametre of the propeller between 400 mm. and 1.300 mm., being made of bronze and manganese with the high mechanical resistance that this implies, as aforementioned.
Big flaps surface, this forming part of the tail itself.
High speed, given that the propeller does not touch the water disturbed by the hull.
Great capacity of manoeuvre, due to the possibility of turning the propulsion up to 180°.
Mounting of the propeller shaft parallel to water.
Possibility that the boat may be totally keeled, gaining stability.
Circulation pump of oil by spiral, without wear between pieces, there being neither friction nor possibility of failure.
Possibility of choosing the direction of rotation of the propeller only by changing the placing of the crown corresponding to the upper truncated group.

DESCRIPTION OF DRAWINGS.

In order to complete the description which is being carried out and for the purpose of helping to a better understanding of the particulars of the invention, a set of drawings is enclosed to this descriptive memorandum as an integral part of it, where, illustratively and not restrictively, the following has been drawn:

Picture 1.- Shows a drawing according to the longitudinal section of the propeller tail, which is the object of the invention, in the external mounting version.

Picture 2.- Shows the same longitudinal drawing of the tail in the internal mounting version.

Picture 3.- Shows, finally, a longitudinal view in section of the directional hydraulic system, based on a rack.

PREFERRED MAKING OF THE INVENTION.

It may be seen in picture 1 that the propeller tail, which is the object of the invention, intended for external mounting, includes a general casing determined by the linking between parts (1), (2) and (3), part (1) corresponding to the so-called upper part, part (2) to the intermediate, and part (3) to the lower part, the general body (4) being fixed to the latter in the lower part by a bulb cover (5), in the body (4) of which the propeller (6) itself is placed.

General casing defined as aforementioned has a lateral part (7) in which the attack pinion (8) is placed and which receives the power from the corresponding engine-gear group with the characteristic that from that pinion (8) pushes a crown (9) mounted over the shaft (10) corresponding to the upper truncated group (11), which is related to the lower truncated group (12) by means of an axial shaft (13), with the insertion of the corresponding attack pinions (14). This is to say that the upper (11) and (12) lower truncated groups are joined to each other, with the insertion of the corresponding attack pinions (14), by means of an axial shaft (13), the whole being inside the aforementioned casing and immersed in oil, being completed in the upper part by a cover (15) which together with the aforementioned shaft (10) forms a pump, on the basis of which a continuous oil-flow is created from one end to the other, achieving efficient cooling and perfect thermal balance.

The fact must be emphasised that the tail is watertight to sea water, and is installed completely full of oil as previously explained, with an expansion cup in the upper level, in such a way that when working, sea water cools its external lower part, at the same time as the oil does so inside. Rotation are complemented with the respective races (16), with securing nuts, etc., showing in the upper part the respective race-carriers (17). The corresponding watertight O-rings joints (18) are included as well as the oil-entrance- connection (19), being complemented with regulating grommets (20) for the truncated groups (11) and (12).

As it has been previously stated, the propeller (6) is mounted over the lower body (4), and more precisely over the so-called tail shaft (21), being fixed to it by means of a nut (22), and in the shaft (21) of which a crown (23) is placed, which receives power from the lower truncated group (12), as the upper crown (9) belonging to the upper truncated group (11) receives it from the attack pinion (8) through which connection to the engine takes place.

The propeller tail so-built forms part of a compact whole and is intended to be anchored externally, specifically to the upper stern (23) of the boat, by means of a metallic support (24) joined to the boat, as well as a fastening plate (25), in such a way that the joint of the latter to the support and to the casing of the tail takes place by means of respective silentbloc (26). The engine and the gear are mounted internally, over the metallic frame, the space occupied by the driving set being therefore reduced, boats of short length being basically benefitted.

Over the lower part (3) of the casing big surface flaps (48) are conceived.

The tail so-built is intended to transmit to the water the power which it receives from the engine through the gear, the final reduction taking place between the engine and the propeller by means of a combination of the two truncated groups (11) and (12) and not in the gear as traditionally happens; all of these in such a way that the transmission of power from the elastic coupling which joins the gear and the tail itself goes through the following mechanisms: upper attack pinion (8), upper crown (9), upper truncated group shaft (10), central connection shaft (13), lower attack pinion (14), lower truncated group (12), lower crown (23), tail shaft (21) and propeller (6).

The reversing of the direction of rotation of the propeller itself (6), in backwards and forwards manoeuvres, occurs in the gear, given that the tail is limited in transmitting it to the water.

In the event that two tails were mounted in a boat, propellers should turn in the direction opposite to the rotation in both manoeuvres, given that if it was not so, the boat would not navigate directly, it being displaced laterally in such a way that in order to achieve that two propellers turn in the direction opposite to the rotation, it is enough with changing the position of the race- carrier piece (17) and the crown itself (9) of the upper truncated group. (11)

On the other hand, and it has previously being stated, the propeller tail is watertight to sea water and is installed completely full of oil and with an expansion cup in the upper level, in such a way that, when working, sea water cools its external lower part, at the same time as oil cools its inner part.

By means of the pump formed by an upper cover (15) and the upper crown-carrier (9) shaft (10), a continuous flow of oil is obtained from one end to the other, achieving efficient cooling and perfect thermal balance, in such a way that the two sole pieces which form the pump do not experience friction and, therefore, there is neither wastage nor failure, with the peculiarity that oil must be drawn to the highest part of the shaft itself (13) and expelled by the attack pinion of the lower truncated group (12).

With regard to the steering system, the same is represented in picture no. 3 and includes a crown (27) and a rack (28), in such a way that a orbitrol attached to the rudder of the boat shall govern the flow of oil in that hydraulic rack (28) mounted in the propeller tail itself. The said steering hydraulic system, as a whole, has been designed bearing in mind the fitting of one, two or more tails per boat.

This hydraulic system includes a piston (29) and an exit ram (30), it having two closing covers (31) and (32), the first of them as a dead light and the second as a perforated lid for the exit of the ram (30), this being intended in order to synchronise the rotation in the event that two propeller tails are mounted.

The said system is completed with friction bands (33), collars (34) and bearing scraper (35), as well as with a fork (37), with adjusts the synchroniced rotation of two tails, and a silentbloc (38), a slide (39), an adjusting bolt (40) and a tightening nut (41).

In the event that a single propeller tail is installed, the two covers (31) and (32) would be deadlight, the bucket (30), the fork (37) and the silentblock (38) being substituted by a securing screw (42) to the piston itself (29), with the help of the grommet.

If two tails are fitted in the boat, it would correspond exactly with that shown in picture no. 3, in such a way that in an end the cover (31) would be mounted with the securing screw (42) of the piston (29), and on the other end the perforated lid (32) synchroniced bucket (30), adjustable fork (37) and the silentbloc (38), would be mounted, with the peculiarity that the silentbloc of both tails would be fixed with two perforated iron hoops and keeping the distance constant and, therefore, the synchrony in rotation.

If three or more propeller tails are installed in both ends of the rotation cylinder of the central tail, an adjustable fork, the silentbloc etc would be mounted, and in the side tails as previously explained and shown in picture no. 3.

In picture no. 2 it may be observed that the propeller tail in the case provided for its internal mounting, which has a salient (43) of the part of the casing (2), for the securing to the corresponding seating (44), which would go welded to the boat itself for the securing of the aforementioned tail, in such a way that in this option the tail will have the corresponding nozzle (45).

It is not deemed necessary to lengthen this description because any expert in the matter may understand the scope of the invention and the advantages that may arise from it.

Materials, forms, size and arrangements of the elements may be changed, provided that this does not mean a change in the essence of the invention.

Terms used in this memorandum may be construed in the widest sense and without restriction.

Claims

Propeller tail for boats, that, being intended to be applied to yachts, coastal fishing boats and the like, and having the purpose of transmitting the power received from the engine through the corresponding gear to the water, is mainly characterised because it is made from a general casing which has inside two truncated groups (11) and (12), the first truncated group receives the rotation movement through a crown (9), through an attack pinion (8), coming from the engine, whereas the lower truncated group (12), through a crown (23), transmits the motion of the shaft (21) in which the corresponding propeller (6) is mounted, both truncated groups (11) and (12) being connected one to another by means of an axial conection shaft (13), with the insertion of the corresponding attack pinion (14). It has been conceived that it will have a cover (15) in the upper part, which together with the shaft (10) for the upper truncated group (11) determines an oil pump which enters inside through the upper connection (19); with the peculiarity of including internally a steering hydraulic system made from a crown (27) in mesh with a rack (28) immersed in oil.
Propeller tail for boats, pursuant to 1st. claim, characterised because it includes internally the corresponding races (16) for the rotating parts, as well as watertight joints (18) and grommets (20) .for the regulation of truncated groups (11) and (12).
Propeller tail for boats, pursuant to the previous claims, characterised because in the steering hydraulic system determined by a crown (27) and a rack (28), a piston (29) and the corresponding exit ram (30) have been foreseen, in such a way that in the ends their respective covers (31) and (32) are included, the latter being perforated for the ram exit (30) in the end of which an adjustable fork (37) with a silentbloc (38) is mounted in order to permit the mounting of two or more propeller tails in the boat.
Propeller tail for boats, pursuant to the previous claims, characterised because in the event of mounting a single propeller tail, covers (31) and (32) are deadlight, without an exit ram (30), adjustable fork (37) and silentbloc (38) and including for the tightening of the piston (29) a screw (42) in the end corresponding to the cover (31).
Propeller tail for boats, pursuant to claims 3rd. and 4th, characterised because the hydraulic steering system also includes a slide (39) pressed by an adjusting screw (49) over which the respective tightening nut (41) is mounted.
Propeller tail for boats, pursuant to the previous claims, characterised because it includes a metallic support (24) which joins it to the corresponding boat, the said joint being made to the upper stern (23) by means of a fastening plate (25) located between a pair of silentbloc (26).
Propeller tail for boats, pursuant to claim no. 6, characterised because it includes big surface flaps (48) in order to cause a high stability to the vessel.
Propeller tail for boats, pursuant to claims 1st to 5th., characterised because part (2) of the casing includes a salient (43) in order to fasten the whole to a seating (44) welded to the boat, also including a nozzle (45) in its upper part for the internal mounting of the propeller tail itself with respect to the boat.