EP0262189B1 - High-pressure hydraulic generator-receiver for power transmission - Google Patents

Abstract

Particular construction of a hydraulic generator-receiver with needle bearings (123) on the driving gear (9) and providing for play compensation between the end plates (21, 22) and the envelope (36), a leak return and a better supply of the pressure zone (34).

Description

The present invention relates to improvements made to a hydraulic generator-receiver according to EP-A-0165884 claiming priority from FR-A-2,564,931, comprising two gears coupled to the inside of a stator, at least the one of them being devoid of mechanical bearing which stator also comprises at least one inlet opening and one return opening for a pressurized liquid, while two flanges close the stator on either side of the two gears on which they ensure a lateral seal and that diametric channels covering an angle of 180 ° are provided in the gears, the stator comprising a flexible envelope (39) subjected externally to a centripetal pressure which allows it to ensure the seal on the tops of the teeth of the gears (9, 10) with helical teeth whose helix angle a is such that tga = 2H / rtMt (H = width of teeth, Mt = apparent modulus located in the envelope between e two flexible flanges (21, 22) with hydrostatic compensation ensuring sealing between these flanges and the faces of the gears, the internal hydraulic balancing being ensured by a hydraulic winding comprising rotor conduits (19) in the gears (9 and 10 ), and stator (23) in the flanges (21 and 22), the successive switches between the rotor (19) and stator (23) conduits being ensured by their ends running past one another on a switching circle (20) , the stator conduits emerging therein in cells (100), and simultaneously on the hollow of teeth at the level of the pitch circle for the other end of the stator conduits (23), to ensure the permanent connection between the hollow of opposite teeth for a number of teeth even, and the hollow of opposite teeth with, an offset of half a step for an odd number of teeth, except in the meshing zones (3) and those respectively diametrically opposite (6), in the latter are created hydraulic bearings diametrically opposite the point of engagement (3) of the gears (9 and 10) so that during the rotation of the gears (9 and 10) said winding relationship the pairs of opposite teeth so as to obtain the same hydraulic pressure in the hollow of teeth for diametrically opposite angular positions and to create two opposite forces on the gears in order to cause their engagement without play.

• que chacun des engrenages a une même nombre de dents, même module de denture, même angle a d'hélice, tel que tg
  
  module apparent, H largeur de denture, donnant un décalage de un demi-pas entre les profils de denture sur les faces;
• que l'équilibrage des pignons est assuré par un système de "bobinage hydraulique" permettant la suppression des paliers classiques et la création de "paliers hydrauliques" assurant un engrènement sans jeu des pignons 9 et 10;
• que l'étanchéité interne est assurée par un système de flasques 21 et 22 - enveloppe 36 avec compensation hydrostatique sur les faces et sur les sommets de dents des engrenages 9 et 10, qui permet un rattrapage des jeux dans les deux directions.
• Ces conditions assurent un débit Q constant, et non plus pulsé, ainsi qu'un vecteur vitesse de déplacement des particules fluides à la génération et à la réception parallèle à l'axe des pignons 9 et 10, les composantes de vitesse résultant de la rotation et de l'inclinaison d'hélice se neutralisant.
• Dans le document EP-A-0165884, la figure 9 définissait un équilibrage secteur par secteur et les figures 18 et 19, les différentes possibilités de réalisation des conduits rotoriques et statoriques; ces deux dispositions sont reprises dans la présente invention.

The designations and references used in EP-A-0165884 are used, as are the main characteristics of the invention described in said document, that is to say:

• that each of the gears has the same number of teeth, same gear module, same helix angle a, such as tg
  
  apparent modulus, H toothing width, giving a half-step offset between the toothing profiles on the faces;
• that the balancing of the pinions is ensured by a "hydraulic winding" system allowing the elimination of conventional bearings and the creation of "hydraulic bearings" ensuring a mesh without play of the pinions 9 and 10;
• that the internal seal is ensured by a system of flanges 21 and 22 - casing 36 with hydrostatic compensation on the faces and on the tops of the teeth of the gears 9 and 10, which allows play to be taken up in both directions.
• These conditions ensure a constant flow Q, no longer pulsed, as well as a speed vector of displacement of the fluid particles at the generation and at the reception parallel to the axis of the pinions 9 and 10, the speed components resulting from the rotation. and the propeller tilt neutralizing.
• In document EP-A-0165884, FIG. 9 defined a sector-by-sector balancing and FIGS. 18 and 19, the different possibilities of making the rotor and stator conduits; these two provisions are included in the present invention.

• opposés à n si le nombre de dents Z est pair;
• opposés à n ± un demi-pas angulaire de denture, si le nombre de dents Z est impair, ces secteurs opposés égaux étant au même potentiel de pression et en même position angulaire sur les deux flasques 21 et 22 et sur l'enveloppe 36.

Sector-by-sector balancing consists in dividing the circumference of the pinion reduced by the value necessary for zone 34 situated around the gear point 3 and the point 6 diametrically opposite thereto, i.e. for example an angular step in 6, and zero steps angular in 3, or an angular step in 6, and an angular step in 3, in an even number 2 N of equal opposite sectors:

• opposite n if the number of teeth Z is even;
• opposite to n ± an angular half-step of toothing, if the number of teeth Z is odd, these equal opposite sectors being at the same pressure potential and in the same angular position on the two flanges 21 and 22 and on the casing 36.

Opposite sectors are equal, but two consecutive sectors can be unequal.

The realization of the rotor conduits is that defined by the form 76 of FIGS. 18 and 19 of the document EP-A-0165884, but with an additional arrangement, that is to say that the rotor circuit is constituted by diametrical bores through the pinions 9 and 10, holes opening into two conduits parallel to the axis of the pinions (or inclined up to the value of the helix angle a), and opposite to n, these two conduits serving four symmetrical switching points on the switching circle 20, these supply symmetrically the fluid bearings between the faces of the flanges 21 and 22 and the faces of the pinions 9 and 10. This symmetry of creation of the fluid bearings is only obtained in the context of the form 76 of rotor and stator conduits.

• la liaison entre les secteurs équipotentiels est permanente;
• les creux de dents passent d'un secteur à une certaine valeur de pression à un autre secteur à une autre valeur de pression, sans risque de court-circuit occasionnant des fuites d'un secteur au suivant.
• les creux de dents opposés à n ou à n ± un demi-pas angulaire de denture sont au même potentiel de pression sauf lors du passage d'un secteur à un autre secteur et sauf aux points de création des "paliers hydrauliques";
• les pignons 9 et 10 sont en conséquence:
• équilibrés dans le cas d'un nombre de dents Z pair;
• équilibrés avec un avantage côté opposé au côté orifice 40 haute Pression correspondant à un demi- pas angulaire de denture en pression dans le cas d'un nombre de dents Z impair;
• la symétrie est totale;
• la liaison entre creux de dents opposés est totalement rompue en 6 et en 3, pour permettre l'équilibrage hydrostatique aux points 6 de création des "paliers hydrauliques".

The whole construction, the holes, the rotor and stator conduits is defined so that:

• the link between the equipotential sectors is permanent;
• the teeth recesses pass from one sector at a certain pressure value to another sector at another pressure value, without risk of short-circuit causing leaks from one sector to the next.
• the hollows of teeth opposite to n or to n ± an angular half-step of toothing are at the same pressure potential except when passing from one sector to another sector and except at the points of creation of the "hydraulic bearings";
• the pinions 9 and 10 are therefore:
• balanced in the case of an even number of teeth Z;
• balanced with an advantage on the side opposite to the orifice 40 high pressure side corresponding to an angular half pitch of teeth in pressure in the case of an odd number of teeth Z;
• the symmetry is total;
• the connection between the hollow of opposite teeth is completely broken at 6 and 3, to allow hydrostatic balancing at the points 6 of creation of the "hydraulic bearings".

The hydraulic generator-receiver according to the invention is characterized in that its rotor circuits in the pinions consist of groups of diametrically opposite conduits on the switching circle and parallel (or inclined to the value of the helix angle) to the axis of the pinions and radials joining the pipes opposite to n to form an H, the high-pressure supply of the permanent total pressure zone being effected by a preferential valve system also allowing the decompression of this zone when desired .

The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it presents and the advantages which it is capable of providing:

Figure 1 is a perspective representation of the invention. The number of teeth Z odd = 15, the 2 N sectors = 6, the helical pinions 9 and 10 mesh at point 3, rotate in the plastic casing 36 and are inserted between the flanges 21 and 22. The take-up of clearances between the flanges 21 and 22, and the pinions 9 and 10 is effected by the action of the 2 N hydrostatic compensation sectors 60 on flanges 21 and 22, and is enabled by the possibility of axial compression of the casing 36.

The pinions 9 and 10 are balanced by the stator conduits formed by the cells 30 on the pitch circle, the conduits 23, the cells 100 on the switching circuit 20, and by the rotor conduits formed by the conduits 102 parallel to the axis of the pinion (or inclined to the value of the helix angle a), opposite to n and the conduits 101 for diametric connection between the conduits 102, the assembly ensuring an equipotential bond between sectors opposite to n if Z even, and at n ± half an angular step of teeth if odd Z. The number of connections D is greater than N so as to provide, by the overlaps between the conduits 102 and the cells 100, a permanent connection between opposite sectors while ensuring sufficient sealing between successive sectors. This permanent connection is broken at points 6 and 3, zone 34 of permanent total pressure to ensure the creation at points 6 of "hydraulic bearings".

This figure 1 also shows the arrangement of the orifices 40 HP-BP, shown parallel to the axes of the pinions and of cylindrical shape. They can also adopt a shape derived from the shape of the fluidd vein generated or received and possibly inclined at the helix angle a.

Figure 2 is a sectional elevation II-II (Figure 3), still in the case of catching clearances by compression of the casing 36. It shows the area 34 and the arrangement of the conduits 101 and 102 in the pinions 9 and 10 .

Figure 3, half-section III-III, half-cut XI-XI (Figure 20) shows the arrangement of the hydrostatic compensation sectors 60 on flanges 21 and 22 in the cs of a symmetrical construction, that is to say with symmetry, with respect to the median plane perpendicular to the axes of the pinions 9 and 10. This arrangement does not correspond exactly to the pressures to be balanced, in the sense that it does not take into account the offset introduced by the helix angle, ie a angular half step

par les alvéoles 30, les conduits 23, les alvéoles 100 statoriques et les conduits 101 et 102 rotoriques. Cette figure 3 montre une possibilité d'équilibrage par un conduit 103 constitué par des perçages, soit au travers du corps 49, soit au travers des couvercles 54 ou 55, sont par une tuyauterie acier extérieure à l'appareil et reliant deux secteurs opposés à

The hydrostatic compensation sectors 60 are materialized by the points 45, the anti-extrusion devices 104 and are balanced at

by the cells 30, the conduits 23, the stator cells 100 and the rotor tubes 101 and 102. This FIG. 3 shows a possibility of balancing by a conduit 103 constituted by bores, either through the body 49, or through the covers 54 or 55, are by a steel piping external to the apparatus and connecting two sectors opposite to

It also presents a realiqation of the conduits 101 from a bore produced by piercing a tooth recess with closure by a brazed plug 105.

Figure 4, half-section III-III, half-section XI-XI (Figure 20), shows the arrangement of the hydrostatic compensation sectors 60 on flanges 21 and 22 in the case of an asymmetrical construction. This arrangement corresponds exactly to the pressures to be balanced in the sense that it takes account of the offset introduced by the helix angle a, that is to say an angular half pitch of toothing

Therefore, the flanges 21 and 22 are however always identical, but in position in the generator-receiver, they only have a central symmetry with respect to the point 3 of meshing at mid-height of the pinions 9 and 10. It also has a possibility of balancing by a conduit 103 and another embodiment of the pinions 9 and 10 in two pieces assembled by a link 106, brazing or sintering.

et seront augumentés si la zone 34 adoptée en 3 est plus faible.It should be noted that FIGS. 3 and 4 show the hydrostatic compensation sectors 60 on flanges 21 and 22 located near point 3 reduced by a certain value for the creation of zone 34 at 3 (in principle an angular pitch of toothing); this in the case where the number of teeth Z is odd. In the case of even Z, these sectors near point 3 will have a normal value if the area 34 in 3 is equal to the area 34 in 6, that is to say an angular pitch of toothing

and will be increased if the zone 34 adopted in 3 is weaker.

FIG. 5, section V-V (FIG. 4) shows the conduits 101 and 102 in the pinions 9 and 10, with the conduits 101 being closed by the plug 105. This figure presents various possible construction variants:

flange 21 made of hard material, therefore no anti-extrusion device 104. the seals 45 and 58 are housed in the cover 54;

flange 22 of plastic material, and comprises an anti-extrusion device 104. The seal housings 45 and 58 are molded in the flange 22.

The casing 36 is plastic, the hydrostatic compensation sectors on the casing 36 are materialized by the clearance 38, the seal 37, the supply orifice 43 and the anti-extrusion device 107. Balancing between two opposite tooth recesses is clearly shown by the cells 30, the conduits 23, the stator cells 100 and the rotor conduits 101 and 102.

FIG. 6 is an external developed view of the casing 36 which shows the hydrostatic balancing sectors 38 on the casing 36 and their supply via the orifice 43. On the axis 3 corresponding to the point of engagement of the pinions 9 and 10 , the non-return 39 supplying the zone 34 according to document EP-A-0165884 has been replaced by an orifice 43, the zone 34 at 3 being eliminated and replaced by a hydrostatic compensation sector at this point, because it is important to have the same pressure on the axis 3 inside and outside of the envelope 36. The role of the non-return 39 supplying the area 34 will be fulfilled by a device with preferred valve.

FIG. 7, section VII-VII (FIG. 2) is a section of the enclosure 36 which shows the detail of the hydrostatic compensation sectors 38 on the enclosure 36 with anti-extrusion device 107 and supply via the orifice 43.

FIG. 8 is a panoramic representation of the stator circuits alveoli 30, conduits 23, alveoli 100, and rotor circuits conduits 101 and 102 in the case of an even number of teeth Z and symmetrical construction of the hydrostatic compensation sectors 60 on flanges 21 and 22. The upper representation shows the arrangement on the envelope 36, with the area 34, the seals 37, the orifices 43. The shape 108 is a shape which extends the cells 30 towards point 6, for the hydrostatic balancing of the hollow teeth at 6 and the creation of "hydraulic bearings" replacing the supply conduit 33 according to document EP-A-0165884. This arrangement makes it possible to better control the hydrostatic balancing at 6 according to the priority operations in generator or or receiver by varying the length of this shape 108.

FIG. 9 is a panoramic representation of the stator and rotor circuits in the case of an odd number of teeth Z and symmetrical construction of the hydrostatic compensation sectors 60 on flanges 21 and 22.

des alvéoles 100 et une inclinaison des conduits 102 à l'angle d'hélice a. Elle permet un équilibrage plus maintenu des creux de dents, les alvéoles 30 pouvant être plus importants angulairement. Les canaux sont inclinés.FIG. 10 is a panoramic representation of the stator and rotor circuits in the case of a odd number of teeth Z and asymmetrical construction of the hydrostatic compensation sectors 60 on flanges 21 and 22. It requires an offset of an angular half-step dd toothing

alveoli 100 and an inclination of the conduits 102 at the helix angle a. It allows more sustained balancing of the tooth hollows, the alveoli 30 being able to be angularly larger. The channels are tilted.

est alors réalisé par une forme spirale de un quart de pas angulaire de denture du conduit de liaison 23 entre les alvéoles 30 et les alvéoles 100. Des variantes intermédiaires sont possibles en fonction des facilités de construction qu'elles procurent.FIG. 11 is a panoramic representation of the stator and rotor circuits in the case of an odd number of teeth Z, and asymmetrical construction of the hydrostatic compensation sectors 60 on flanges 21 and 22. This construction avoids the offset of an angular half step of teeth cells 100 between the flanges 21 and 22, and therefore to keep the conduits 102 parallel to the axis of the pinions 9 and 10. The offset of

is then produced by a spiral shape of a quarter angular pitch of toothing of the connecting conduit 23 between the cells 30 and the cells 100. Intermediate variants are possible depending on the construction facilities they provide.

FIGS. 12, 13, 14 and 15, according to section II-II, represent various alternative embodiments of the flange clearance take-up assembly 21 and 22, envelope 36.

• enveloppe 36 dure et non déformable, flasques 21 et 22 plastiques;
• flasques 21 et 22 durs et non déformables; enveloppe 36 plastique;
• flasques 21 et 22, enveloppe 36 plastiques.

The take-up of the clearances on the faces and on the tops of the teeth of the pinions 9 and 10, that is to say in two concurrent directions, requires that, on at least one of these two directions, the plasticity of the materials allows these backlash in the other direction, which leads to three possible schemes in the choice of materials used:

• envelope 36 hard and non-deformable, flanges 21 and 22 plastic;
• hard and non-deformable flanges 21 and 22; plastic envelope 36;
• flanges 21 and 22, envelope 36 plastics.

• Figure 12 selon coupe II-II: Flasques 21 et 22 plastiques et enveloppe 36 dure avec garniture plastique 48. Logements des joints par moulage dans les couvercles 54 et 55 ou dans les flasques 21 et 22, et dans la garniture plastique 48 ou dans le corps 9.
• Figure 13 selon coupe II-II: Flasques 21 et 22 plastiques et enveloppe 36 dure ou plastique.

The realization of the seal housings of the hydrostatic compensation sectors which should preferably be done by molding, leads to the following different constructions:

• Figure 12 according to section II-II: Plastic flanges 21 and 22 and hard casing 36 with plastic lining 48. Housing of the seals by molding in the covers 54 and 55 or in the flanges 21 and 22, and in the plastic lining 48 or in the body 9.
• Figure 13 according to section II-II: Plastic flanges 21 and 22 and hard or plastic envelope 36.

Seal housings by molding in the covers 54 and 55 or in the flanges 21 and 22 and in the body 49 or in the casing 36.

Note in this figure 13, the 45 ° joint plane between the casing 36 and the flanges 21 and 22, an angle which allows better sealing between the faces in contact, casing 36 - flanges 21 and 22, as a result of an application of the pressures of the zone 34 to ensure a contact without play, in particular on the Low Pressure sectors.

• Figure 14, according to section II-II: Hard flanges 21 and 22, with plastic lining 109, and plastic envelope 37. Seal housings by molding in the covers 54 and 55 or in the plastic lining 109 and in the body 49 or in the casing 36.
• Figure 15, according to section II-II: Hard or plastic flanges 21 and 22, and plastic envelope 36. Seal housings by molding in the covers 54 and 55 or in the flanges 21 and 22 and in the body 49 or in the casing 36.
• Figure 16, pair XVI-XVI (Figure 4) shows the leakage return to the low pressure sector produced from the bore of the flanges 21 and 22 by a conduit 110 equipped with a non-return 111 and opening through a conduit 112 in a hydrostatic compensation sector 60 BP-HP, the assembly being closed by a stopper plug 113.

Each flange 21 and 22 will be equipped with four of these non-return devices for all operating cases, direction of rotation, generator and receiver, ie two devices per bore. These devices can be considerably simplified, in particular in the plastic flanges 21 and 22, the non-return 111 being able to be produced by a metal washer located on the inlet of the discharge duct in the hydrostatic compensation sector 60.

Mt module apparent 5, H largeur de denture 4. L'angle d'inclinaison a, 120, pourra pour les unités tournant à grande vitesse de rotation, prendre des valeurs de l'ordre de 45°, en particulier loes de l'utilisation de denture chevrons. Dans ces conditions, les conduits HP-BP sont ramenés perpendiculaires aux axes des pignons, et positionnés comme sur les générateurs et récepteurs à engrenages à denture droite.FIG. 17, section XVII-XVII (FIG. 3) shows the new device for pressurizing and decompressing the zone 34 which is the zone of total permanent pressure generated. The supply and the decompression of the zone 34 is made either by the conduit 114, or by the conduits 117, 118 the selection being made by a preferential valve 116 opening into the conduit 115 leading to the zone 34. This device is closed by the plug 119. The valve 116 keeps free the connection between the sector at the top pressure and zone 34 and instantly allows the tilting of this connection when changing the sector for high pressure. It does not close when the pressure drops above the low pressure and therefore allows decompression. It only closes when a sector goes into low pressure. Zone 34 is therefore always at the maximum pressure generated or received. This figure shows the orifice 40 HP-BP inclined at the helix angle a, 120 such that

Mt apparent module 5, H tooth width 4. The angle of inclination a, 120, may for units rotating at high rotational speed, take values of the order of 45 °, in particular in use herringbone teeth. Under these conditions, the HP-BP conduits are brought back perpendicular to the axes of the pinions, and positioned as on the generators and receivers with gears with straight teeth.

• un noyau central 121 réalisé avec les demi-conduits 102 sur le cercle de commutation 20, et les conduits 101 percés à travers ce noyau;
• une couronne dentée 122 réalisée avec l'autre partie des conduits 102 sur le cercle de commutation 20. Cette couronne sera, soit usinée et assemblée par brasure 106 sur le noyau 121, sont réalisée par frittage avec ancrages sur le noyau 121 au niveau du cercle de commutation 20.

Figures 18 (half-section II-II) and 19 (partial section through a conduit 101) show an embodiment of the pinions 9 and 10 in two parts:

• a central core 121 produced with the half-conduits 102 on the switching circle 20, and the conduits 101 drilled through this core;
• a ring gear 122 produced with the other part of the conduits 102 on the switching circle 20. This ring will either be machined and assembled by soldering 106 on the core 121, are produced by sintering with anchors on the core 121 at the level of the circle switching 20.

FIG. 20, section II-II, is a variant of the protection of the driving pinion 9 against the external stresses transmitted by the power take-off: shocks, parasitic or internal forces resulting from possible imbalances of the hydrostatic compensations. The pinion 9 is supported at the covers 54 and 55 by two needle bearings 123 which position this pinion 9 relative to the body 49, to the covers 54 and 55, the other constituent parts of the heart of the generator-receiver, pinion 10, flanges 21 and 22, envelope 36 balancing normally with respect to this positioning of the pinion 9 in the same way as in the preceding situations. This device is a variant of the power take-off 52 for protecting the pinion 9. It will also, in combination with the hydrostatic compensation devices, correct certain minor imbalances resulting from operation and other imbalances such as those resulting from compressibility of the hydraulic fluid in the case of an even number of teeth Z.

General rules of construction

The theoretical study will focus on determining the maximum working pressure, the number of teeth Z, the width of teeth H, 4, the apparent modulus Mt, 5, or real Mn of teeth, the angle of inclination a of propeller, the diameter of the output shaft d, the number of sectors 2N, the number of connections D through the pinions 9 and 10 in the width H of teeth 4, depending on the characteristics of the generator-receiver, power , torque, maximum rotation speed w, maximum flow speed V meters per second allowed for hydraulic fluid, priority direction of rotation in generator or receiver, efficiency, price ...

A generator-receiver of small displacement, priority in generator, rotating at high speed of rotation, 3000, 4000 revolutions per minute, will have a small number of sectors N, either N = 2, a small number of connections D, or D = 3 , or D = 4, and a small toothing width H, 4, or a chevron toothing, to limit as much as possible the flow speed of the hydraulic fluid to the maximum speed allowed.

On the other hand, a generator-receiver of large displacement, rotating at low speed 100, 200 or 300 revolutions per minute, priority in receiver, will have a large number of sectors, i.e. N = 4, 5, 6 ... and a large number of connections, ie D = 5, 6, 7 ... and a large tooth width H, 4, allowed by the flow speed of the hydraulic fluid.

Choice of pressure

Pressure adopted the higher the higher the power to be transmitted. Choose the highest possible pressure, compatible towards low powers, with the design requirements of sectors N, and towards high powers with admissible mechanical stresses in gears which are of the order of three, four times the hydraulic pressure . These pressure values can vary from 100 to 800 bars.

• Z impair, soit Z = 9, 11, 13, 15, 17, 19, 21 ...

Choice of number of teeth Z:

• Odd Z, i.e. Z = 9, 11, 13, 15, 17, 19, 21 ...

High rotational speeds w: Z as low as possible, possibly with herringbone gears for very high rotational speeds w.

Small rotational speeds w: Z increases and this increase is partly linked to the mechanical characteristics of the envelope 36. The yield and the price increase if Z increases for the same characteristics of the generator-receiver. The number of teeth Z is associated with the tooth width H, 4, for its determination, as a function of the maximum speed of rotation w, of the maximum speed V meters per second of flow of the hydraulic fluid.

Choice of tooth width H, 4:

If V is the maximum flow speed of the hydraulic fluid in meters per second, w the maximum rotation speed in revolutions per minute, H will be given in meters, by

The speed of flow of the hydraulic fluid is the axial component of the speed of movement in the hollow of the tooth: only this axial component is to be taken into account, the tangential component is canceled by the speed of rotation of the pinion. Everything happens as if the generation (or reception) were ensured by a tooth-piston moving at constant speed in a hollow tooth cylinder, this speed being Z times the width of teeth H for a time corresponding to one revolution of pinion, the direction being axial.

Choice of the apparent module Mt, 5:

Calculation of Mt for the transmission of power as a function of the pressure adopted, the speed of rotation w, the number of teeth Z, and the width H, 4 of teeth.

Choice of the propeller tilt angle a:

Calculation from

Choice of the output shaft diameter d:

Calculation from the maximum torque to be transmitted, and the maximum stress allowed.

Choice of the number of sectors 2 N:

Determination of the angular value of a sector:

The step in value 3 with an angular toothing pitch, zone 34, is distinct from the sectors located near point 3.

The bearing in 3 has an angular toothing pitch, zone 34, amputated by half an angular toothing pitch, the sectors located on either side of point 3.

• amputée de la moitié de la zone 34, si Z est impair;
• normale, si Z est pair.

Sectors N on either side of zone 34 in 3 will therefore have a value:

• amputated by half of area 34, if Z is odd;
• normal, if Z is even.

The adoption for the hydrostatic compensation sectors on flanges 21 and 22, of a symmetrical arrangement with respect to the median plane perpendicular to the axes of the pinions 9 and 10 and at mid-height thereof, or of an asymmetrical arrangement, that is to say with an offset of half an angular step of teeth, to better correspond to the pressures to be balanced, will depend on the materials used, but the second solution must satisfy all the conditions.

The table gives the possible choices for the sectors: the values underlined solid lines, are those which make it possible to obtain the same pressure inside and outside of the envelope 36 on the axis 3, the values underlined lines dotted lines lead to possible constructions as a receiver, but with a lower pressure value outside than inside the envelope 36 on axis 3

The choice of the number of 2N sectors will depend on the characteristics sought; if N increases, the yield and the price increase. The more the displacement per revolution increases, the more Z and N will increase to solve the problems of resistance and dimensioning of the envelope 36. However, the study should always seek to carry out the construction with Z and N as weak as possible.

Practical production of parts:

Body 49: obtained by molding, aluminum-based alloy, cast iron or steel. Possible molding of the seal housings.

Lids 54 and 55: obtained by molding, aluminum-based alloy, cast iron or steel. Possible molding of the seal housings.

• en matériaux plastiques ou composites, réalisation par moulage avec logements de joints.
• en matériaux durs, alliage aluminium plomb, à bonnes caractéristiques de frottement
• en matériaux durs, plus garniture plastique 109, réalisation par moulage avec logements de joints.

Flanges 21 and 22:

• made of plastic or composite materials, produced by molding with seal housings.
• made of hard materials, lead aluminum alloy, with good friction characteristics
• made of hard materials, plus plastic lining 109, produced by molding with seal housings.

• en matériaux plastiques ou composites, réalisation par moulage avec logements des joints
• en matériaux durs, acier nitruré
• en matériaux durs, plus garniture plastique 48 acier nitruré et garniture plastique adhérisée par moulage avec logements des joints.

Envelope 36:

• made of plastic or composite materials, produced by molding with seal housings
• hard material, nitrided steel
• made of hard materials, plus plastic lining 48 nitrided steel and plastic lining bonded by molding with seal housings.

Sprockets 9 and 10: hard materials, case hardening or nitriding steel.

• par usinage complet en une seule partie ou en deux parties assemblées par brasure;
• par frittage d'une couronne dentée sur un noyau central préalablement usine;
• par frittage complet.

Production:

• by complete machining in a single part or in two parts assembled by brazing;
• by sintering a ring gear on a central core previously produced;
• by complete sintering.

Precisions required: pairing of the widths of teeth H, 4, pinions 9 and 10, surface conditions of the order of 0.20 to 0.40 on the tops of teeth and on the faces, faces perpendicular to the teeth profiles.

Claims (9)

1. A hydraulic generator/receiver for power transmission comprising two coupled gears, at least one of which has no mechanical bearing, within a stator which also includes at least one inlet opening and one return opening for the liquid under pressure, while two blank flanges enclose the stator on either side of the two gears providing a lateral seal therefor and diametrical channels at an angle of 180° are provided in the gears, the stator having a flexible envelope (39) subjected externally to a centripetal pressure which causes it to provide a seal at the tips of the teeth in helically toothed gears (9, 10) wherein the helix angle a is such that tan a = 2H/n Mt (H = tooth width, Mt = apparent modulus) located within the envelope between two flexible flanges (21, 22) with hydrostatic compensation making a seal between these flanges and the faces of the gears, internal hydraulic balance being provided by a hydraulic winding comprising rotor conduits (19) within the gears (9 and 10) and stator conduits (23) within the flanges (21 and 22), successive switching between the rotor conduits (19) and the stator conduits (23) being effected through their ends passing one before the other over a circle of commutation (20), the stator conduits there opening into recesses (100), and simultaneously over the tooth spaces in the pitch circle at the other end of the stator conduits (23) in order to provide a permanent link between opposite tooth spaces when the number of teeth is even, and the opposite tooth spaces offset by half a step when the number of teeth is odd, except in the gearing zones (3) and those respectively diametrically opposite (6), hydraulic bearings being created in the latter diametrically opposite the meshing point (3) of the gears (9 and 10) so that as the gears (9 and 10) rotate the said winding places opposing pairs of teeth in a relationship so as to provide the same hydraulic pressure in the tooth spaces for diametrically opposite angular positions and two reverse forces are created on the gears so that they engage without play, characterised in that the rotor circuits in the gears (9, 10) consist of groups of conduits (102) which are diametrically opposite in the circle of commutation (20) and parallel (or inclined at the angle of helical pitch) to the axis of the gears (9, 10) and radial (101) joining together the conduits (102) with a displacement of n to form an H, the high pressure feed to the permanent total pressure zone (34) being provided by means of a preferential valve system (116) whereby this zone (34) may also be decompressed when desired.

2. A hydraulic generator/receiver according to claim 1 characterised in that balancing between the sectors is effected by means of a stator winding of conduits (103) connecting sectors having the same pressure potential, these conduits (103) being formed within the body (49) or within the covers (54) and (55) by a series of bores, or by steel pipes outside the generator/receiver.

3. A hydraulic generator/receiver according to any one of the foregoing claims, characterised in that the hydrostatic compensation sectors should be designed in number and size so that the hydraulic pressure is identical within and outside the envelope (36) at point (3) corresponding to the meshing point, this arrangement also enabling outside conduits (103) and inside conduits (101 and 102) to be combined in order to balance the sectors, in particular for units of small volumetric capacity and high rotation speed.

4. A hydraulic generator/receiver according to any one of the foregoing claims, characterised in that the gaps between the teeth at points (6) are pressurised in order to provide hydrostatic compensation for the "hydraulic bearings" by an extension (108) of the recesses (30), whose size will depend on the friction and sealing conditions at those points and priority functioning as a generator and direction of rotation.

5. A hydraulic generator/receiver according to any one of the foregoing claims, characterised in that the gears (9) and (10) are constructed in one piece or in two pieces, and in the latter case consist of:

a central core (121) pierced with radial conduits (101) and axial half conduits (102),

a toothed ring (122) brazed or centred onto the central core (121) with half conduits (102) identical to those in the core.

6. A hydraulic generator/receiver according to any one of the foregoing claims, characterised in that the hydrostatic compensation sectors (60) on plastic flanges (21) and (22) and (38) on plastic envelope (36) are fitted with anti-extrusion metal dishes (104) and (107).

7. A hydraulic generator/receiver according to any one of the foregoing claims, characterised in that the assembly comprising flanges (21) and (22) and envelope (36) permits play to be taken up in two intersecting directions:

an axial direction on the faces of gears (9) and (10),

a radial direction on the tips of the teeth of gears (9) and (10), will be made of material which is plastic in at least one of the two directions:

hard envelope (36), plastics flanges (21) and (22),

hard flanges (21) and (22), plastics envelope (36),

flanges (21) and (22), plastics envelope (36).

8. A hydraulic generator/receiver according to any one of the foregoing claims, characterised in that the gears (9) and (10) may be constructed with symmetrical herringbone gearing.

9. A hydraulic generator/receiver according to any one of the foregoing claims, characterised in that the gear (9) may be supported at the covers (54) and (55) by needle roller bearings (123) which position this gear (9) around which the other components, gear (10), flanges (21) and (22), envelope (36), balance each other normally with respect to this position, as in the foregoing structures.

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