WO2000068598A1

WO2000068598A1 - Hydrokinetic coupling apparatus

Info

Publication number: WO2000068598A1
Application number: PCT/FR2000/001151
Authority: WO
Inventors: Gustave Chasseguet; Philippe Cossonniere; Daniel Satonnet; Frédéric Sauvage
Original assignee: Valeo
Priority date: 1999-05-05
Filing date: 2000-04-28
Publication date: 2000-11-16
Also published as: JP2002544447A; DE10081340B4; DE10081340T1; FR2793292A1; FR2793292B1

Abstract

The invention concerns a hydrokinetic coupling apparatus comprising a housing (11) including, rotationally symmetrical about an axis, a casing (15-18) provided with a transverse wall (16) capable of being linked in rotation with an input shaft and a blade wheel or impeller (20) capable of driving in hydrokinetic transmission a bladed turbine wheel (28), integral with a hub (35) adapted to be linked in rotation to an output shaft (32), the impeller (20) and the turbine wheel (28) consisting of bladed shells (18-55) (21-29) integral with the inner surface (19-56) of the shells (18-55): the value of the ratio L/H is less than 0.55 and the value of the ratio I/H is not more than 0.35.

Description

"Hydrokinetic coupling device"

The invention relates to a hydrokinetic coupling device of the type comprising a rotating casing internally forming a paddle wheel capable of hydrokinetically driving a paddle wheel impeller housed in this casing. A known hydrokinetic coupling device comprises a casing comprising, of revolution about an axis, on the one hand, an envelope provided with a transverse wall suitable for being linked in rotation to a driving shaft and, on the other hand, an impeller or impeller, capable of hydrokinetically driving a impeller of an impeller, secured to a hub capable of being linked in rotation to a driven shaft.

We have always sought to reduce the axial size of such hydrokinetic coupling devices, in order to obtain, on the one hand, ease of installation in a transmission and, on the other hand, weight savings, due not only to the size of the device but also to the volume of the fluid it contains, which can be added to those already obtained by the use of materials such as thermoplastics and / or thermosets, alloys of synthetic materials, composites , assembled by ultrasonic welding, gluing, gluing or any other means, these weight savings being accompanied by a reduction in cost. Of course, this reduction in axial size must not be accompanied by performance losses which could be caused by the appearance of energy losses in the flow of the fluid due to detachments, recirculations, or the appearance of the phenomenon. cavitation.

Such hydrokinetic coupling devices can be applied in particular to motor vehicles, whether they are for tourism, leisure or industrial use, and as is known in such applications a reduction in axial dimensions is very much sought after.

The impeller and the turbine being made up of shells having vanes integral with the internal face of the shells, if L is designated the maximum width measured axially of the internal circuit available for hydraulic fluid contained in the device, and by H height, measured radially said internal circuit, there has already been proposed, in particular in document US-A-5,241,820, a hydrokinetic coupling device with reduced axial bulk in which the IJH ratio is between 0.55 and 0.65; according to this document, when this ratio is less than 0.55, vortices appear and the performance of the device is degraded.

The Applicant has found that it is possible to lower the value of the ratio IJH below 0.55 insofar as, if I designates the width measured axially in line with the portion of said circuit closest to the axis of the part furthest from the axis, the value of the W / H ratio is at most equal to 0.35.

Thus, according to the invention, a hydrokinetic coupling device comprising a casing comprising, of revolution about an axis, on the one hand, an envelope provided with a transverse wall suitable for being linked in rotation to a driving shaft and , on the other hand, an impeller or impeller, capable of hydrokinetically driving a impeller of an impeller, secured to a hub capable of being linked in rotation to a driven shaft, the impeller and the turbine wheel being constituted of shells having vanes integral with the internal face of the shells, in which L is the maximum width measured axially of the internal circuit at the disposal of the hydraulic fluid contained in the apparatus, I the width measured axially in line with the portion of said circuit most close to the axis of the part furthest from the axis, and H the height measured radially of said internal circuit, characterized in that the value of the ratio IJH is less than 0.55 and the value of the ratio rt l / H is at most equal to 0.35.

Advantageously, if R (m) designates the distance to the axis of the point of the hydraulic circuit closest to the axis and R (L) the radius of the circle on which the maximum width L is placed, the ratio R (m) / R (L) is between 0.6 and 0.8.

Preferably, the width I of the circuit being at a distance R (l) from the axis, the ratio l / L is between 0.6 and 0.7 and the ratio R (l) / R (m) between 2 , 27 and 2.41.

Advantageously, the width I of the circuit being at a distance R (l) from the axis, the ratio R (L) / R (l) is between 0.55 and 0.75.

Preferably, if R (M) denotes the distance to the axis of the point of the hydraulic circuit furthest from the axis, the ratio R (m) / R (M) is between 0.35 and 0.45. Advantageously, the internal profile of the circuit is, in axial section, symmetrical with respect to a transverse plane, perpendicular to the axis.

As a variant, the internal profile of the circuit is, in axial section, slightly inclined on the axis so that the external wall of the shell of the impeller is generally perpendicular to the axis.

Advantageously, the impeller and the turbine are associated with a reactor for constituting a torque converter.

Preferably, the torque converter has a central guide core for the fluid. Advantageously, the core is in three parts carried respectively by the impeller, the turbine and the reactor.

As a variant, the core is in two parts, one of which is carried by the impeller and the other by the reactor.

According to another variant, the core is in one piece carried by the impeller or the turbine; the core is in the form of a ring folded circumferentially in accordion.

According to yet another variant, the core is in one piece carried by the reactor; the core is toroidal, hollow or solid; the core is of planar shape, being produced directly from a conformation of the reactor; the core is generally of planar shape and comprises an axial orientation foot by which it is secured to the blades of the reactor, for example by force fitting or by overmolding; the core is in the form of a ring folded circumferentially in accordion.

Advantageously, inside the envelope is placed a locking clutch intervening between the turbine and the envelope, said clutch comprising a torsion damper, a piston mounted axially movable and at least one friction lining suitable for being tightened between said piston and the internal face of the transverse wall; the torsion damper comprises springs with circumferential action interposed between two parts, guide washer and web, one of these parts being integral in rotation with the friction lining and the other with the turbine.

The presence of the locking clutch, usually called "LOCK-UP", makes the coupling device particularly suitable for application to motor vehicles. The turbine wheel inside the casing is driven by the so-called impeller, thanks to the coupling created by the fluid circulating in the casing and, after starting the vehicle, the locking clutch intervenes to avoid the phenomena of sliding between the two wheels, securing in rotation the driven shaft with the driving shaft.

According to a preferred embodiment, the hydrokinetic coupling device comprises a sub-assembly, advantageously preassembled, essentially comprising the turbine wheel, the web, the guide washer and the circumferential springs. The guide washer is coupled to the web with circumferential play corresponding to the range of action of the springs. With such an arrangement, a friction disc carrying the friction lining is interposed between the internal wall of the casing and the piston movable axially therein, actuated by the oil pressure at the time of locking. The friction disc is rotatably coupled to the web. Alternatively, the friction disc is rotatably coupled to the guide washer.

To better understand the object of the invention, we will now describe, by way of example, purely illustrative and not limiting, an embodiment shown in the accompanying drawings. In these drawings:

- Figure 1 is a half section of a hydrokinetic coupling device according to the invention;

- Figure 2 is a view similar to Figure 1, illustrating a variant;

- Figure 3 is a view similar to Figure 1, illustrating another variant;

- Figures 4 to 6 are partial sectional views similar to Figure 2 showing variants of the inner core carried by the impeller, Figure 6 being a view along arrow VI of Figure 5;

- Figures 7 to 12 are partial sectional views similar to Figure 2 showing variants of the inner core carried by the reactor, Figure 11 being a view along arrow XI of Figure 10;

- Figure 13 is a partial sectional view similar to Figure 2 showing a variant of the inner core carried by the impeller and the reactor; - Figures 14 and 15 are partial views similar to Figure 3 and each show another variant of apparatus according to the invention.

The hydrokinetic coupling device shown in FIG. 1 comprises, arranged in the same sealed casing forming an oil pan 11, a torque converter 12 and a locking clutch 13. The casing 11 forms a driving element and is suitable for be linked in rotation to the crankshaft of an internal combustion engine of a motor vehicle. This annular casing comprises an envelope composed of a first shell 15 comprising an annular transverse wall 16 and of a second shell 18 facing the first and shaped so as to define an impeller wheel 20, with vanes 21.

The blades of this wheel are integral with the internal face 19 of the second shell 18. The shells 15, 18 are connected, here by welding; alternatively, they can both be welded to the same annular part, not shown, constituting a starter ring intended to be driven by the starter of the vehicle. To do this, the annular part has a toothing at its outer periphery. The torque converter 12 also includes a turbine wheel 28 provided with blades 29 facing the blades 21 of the impeller and a reactor wheel 30.

The turbine wheel 28 is linked in rotation to a driven shaft 32 by being secured by rivets 33 to an annular flange 34 carrying a hub 35 toothed coupled to the driven shaft 32.

The shell 18 has a sleeve 38 mounted to rotate in a housing nose 24.

A centering hub 40 is welded centrally to the first shell 15; it has a cylindrical surface forming a sliding bearing 41 for an actuating piston 44 of the locking clutch 13. The latter has a friction disc 46 suitable for being clamped between the internal face of the annular transverse wall 16 and a surface plane of said piston 44 when the latter is urged, under the effect of the oil pressure, towards said annular transverse wall 16. The friction disc 46 is coupled in rotation to an annular piece of pressed sheet metal hereafter called veil 52 The disc 46 comprises a metal support coated on each of its faces with friction linings suitable for being clamped in the above manner between the wall 16 and the piston 44. Furthermore, another annular part of the torsion damper, hereinafter called guide washer 50, is fixed to the turbine wheel 28. Said guide washer 50 and said web 52 are shaped to constitute stops circumferential against which bear the corresponding ends of helical springs 54. The guide washer 50 is coupled to the web 52 with circumferential play allowing the springs 54 to play the role of torsional damper and absorb the torque peaks.

The turbine wheel 28 comprises an annular shell 55 on the internal face 56 of which are fixed its blades 29; likewise, the vanes 19 of the impeller 20 are fixed on the internal face 19 of the shell 18.

The internal circuit available to the hydraulic fluid is defined between the internal faces 19 and 56, the shells 18 and 55, and, of course, by the bottom 31 of the reactor 30; as known per se, centrally the fluid is guided by a core 60, here in three parts 61, 62, 63 carried respectively by the free edge of the blades 21, 29 and 36, of the impeller 20, of the turbine 28, and of reactor 30.

If, on the one hand, L designates the maximum width of this circuit, measured axially and corresponding to the maximum axial distance separating the internal faces 19 and 56 of the impeller 20 and of the turbine 28, and, d on the other hand, H its height, measured radially, corresponding to the maximum radial distance separating the lowest part of the bottom 31 of the reactor 30 and the highest root of the blades 21 and 29 of the impeller 20 and of the turbine 28 facing each other, the value of the IJH ratio is less than 0.55.

Furthermore, if I designate by I the width of said circuit measured axially in line with the portion closest to the axis, from the most distant part, the value of the w / h ratio is at most equal to 0 , 35.

Here, the portion closest to the axis, from the part farthest from the axis, from the circuit, that is to say defined between the external parts, here transverse, of the blades 21 of the impeller 20 and blades 29 of the turbine 20, is in line with the external part of the core 60. Thanks to these arrangements, the device, whose axial section of the circuit is in the shape of an egg, can be narrower than those of the prior art, with equal performance. Of course, as is known in the art, it is arranged so that the section of the passage of the fluid, defined between the shells and the core 60, is substantially constant whatever the radius where it is measured.

According to a first application of the invention, if we designate by R (m) the radius on which the point of the circuit is located closest to the axis, more precisely the distance to the shortest axis from the bottom 31 of reactor 30, and by R (L) the radius on which the maximum width L is placed, in such an egg-shaped profile the ratio R (m) / R (L) is advantageously between 0.6 and 0.8. In addition, it is good to arrange for the ratio l / L to be between 0.6 and 0.7, and for the ratio R (l) / R (m) to be between 2.27 and 2, 41, in which I denotes the width of the circuit at a distance R (l) from the axis.

According to another application of the invention, it is arranged that the ratio l / L is between 0.6 and 0.7, and that the ratio R (L) / R (l) is between 0.55 and 0.75. According to another application, if R (M) designates the distance to the axis of the point of the hydraulic circuit furthest from the axis, that is to say the distance to the largest axis of the foot of the blades 21 and 29 of the impeller 20 and the turbine 28, arrangements are made so that the ratio R (m) / R (M) is between 0.35 and 0.45.

Excellent results are obtained when all of the above conditions are met.

Thus, according to a first exemplary embodiment which has given satisfaction, IJH = 0.52, w / H = 0.34, R (m) / R (L) = 0.71, l / L = 0.65, R (l) / R (m) = 2.36, R (L) / R (l) = 0.60 and R (m) / R (M) = 0.38.

According to a second example, IJH = 0.54, w / H = 0.34, R (m) / R (L) = 0.59, l / L = 0.62, R (l) / R (m) = 2.27, R (L) / R (l) = 0.74 and R (m) / R (M) = 0.38.

According to a third example, IJH = 0.52, w / H = 0.34, R (m) / R (L) = 0.8, l / L = 0.65, R (l) / R (m) = 2.41, R (L) / R (l) = 0.52 and R (m) / R (M) = 0.38.

In these examples, the internal profile of the circuit is in axial section symmetrical with respect to a transverse plane, perpendicular to the axis, as visible in FIG. 1.

Thanks to the invention, as can be seen, the egg shape of the circuit allows the implantation of the locking clutch 13 by leading to a 12-clutch 13 converter assembly of small axial size. In Figure 1, the web 52, integral with the friction disc 46, has the right of the springs 54 of the legs of axial orientation for support thereof; the guide washer 50 in the form of a ring secured to the external part of the shell 55 of the turbine 28 has locally a U-shaped section whose wings frame the axial tabs of the web 52.

According to Figure 2, the guide washer 50 is formed at the outer periphery of a plate 58 secured at its inner periphery by the rivets 33 to the flange 34 of the hub 25; it is to this plate 58 that the turbine 28 is fixed at 59. Of course, the structures can be reversed; so according to the figure

3, it is the guide washer 50 which is secured to the friction disc 46 while the web 52 is secured to the shell 55 of the turbine 28.

According to FIGS. 1 to 3, the core 60 is in three parts 61, 62, 63 each of which is carried by the blades of the impeller 20, of the turbine 28 and of the reactor 30.

Variants are possible.

According to Figure 4, the core 70 is in one piece, toroidal in shape and carried by the vanes 21 of the impeller 20 to which it is electrically welded or brazed; thanks to this arrangement, the turbine 28 in particular, with its shell 55 and its blades 29, can be obtained in one piece by molding, for example being made of plastic.

According to Figures 5 and 6, the core 80 is also in one piece, carried by the vanes 21 of the impeller 20, but here the core 80 is a ring folded circumferentially in accordion; thus, it can be made of stamped steel and fixed to the impeller 20 for example by welding, brazing or otherwise.

While being in one piece, the core can be carried by the reactor 30 instead of being carried by the turbine 20; Figures 7 to 12 show examples of such a core. According to FIG. 7, the core 90 is toroidal in shape secured to the reactor

30 for example by overmolding, the 30-core reactor assembly 90 being a part of the bi-material type. According to FIG. 8, the core 91 is of planar shape, being produced directly from a one-piece conformation of the reactor 30 itself.

According to Figure 9, the core 92 is generally of planar shape and comprises an axial orientation foot by which it is secured to the blades 36 of the reactor 30, at the outer edge thereof; this joining is obtained by any suitable means such as press fitting, bonding or other.

According to the variant of FIGS. 10 and 11, the core 93 is of the same kind as that of the core 80 of FIGS. 5 and 6, folded circumferentially in an accordion, but here it is carried by the reactor 30. According to FIG. 12, the core 94 is of the kind of that of the core 90 of FIG. 7 but here it is of solid form instead of being of hollow form as in FIG. 7; moreover, here the core 94 and the reactor 30 are in one piece while in FIG. 7 the core 90 is overmolded.

It is also possible to constitute the core in two parts, one of which is carried by the turbine 20 and the other by the reactor 30. FIG. 13 illustrates such a possibility; according to this figure, the core consists of a part 95 of the conventional type carried by the turbine 20 and a part 96, of the kind of that of the core 91 of FIG. 8, of generally planar shape, carried by the reactor 30 .

According to a variant not shown, the core is of the kind described in FIGS. 5 and 6, or 10 and 11, but is carried by the turbine 28.

Of course, as shown in the figures, the shape of the blades, in particular their free edge, of the pump or turbine or reactor member devoid of core element is adapted to that of the core which they follow at best.

In the variants described so far, the internal profile of the circuit of the torque converter 12 is symmetrical with respect to a transverse plane, perpendicular to the axis.

While remaining within the scope of the invention, it is possible to give this profile an asymmetrical shape.

According to the variant of FIG. 14, the egg shape of the circuit is slightly inclined on the axis until the outer wall of the shell 18 supporting the impeller 20 is generally perpendicular to the axis. This arrangement allows, with equivalent axial dimensions of the coupling device, to reserve more space for the locking clutch 13 at the outer periphery, or, for the same clutch, to reduce the axial size of the device.

According to Figure 15, the outer wall of the shell 18 supporting the turbine 20 is also perpendicular to the axis; here, the shell 55 of the turbine 28 has moreover been deformed in line with the clutch 13 by creating a recess therein 57 to increase the space available for the clutch 13; in parallel, the part 62 of the core 60 carried by the turbine 28 carries a boss 67 oriented towards the inside of the core 60, the shape of the boss 67 matching that of the subsidence 57 by extending along the latter while respecting the constant passage section regardless of its diameter.

Advantageously, a preassembled subassembly is produced essentially comprising the turbine wheel 28, the guide washer 50, the web 52, and the circumferential springs 54. To do this, said guide washer 50 is coupled to the web with a circumferential clearance allowing the action of the springs 54 and for this purpose it comprises legs directed radially inwards, engaged in circumferential grooves obtained by folding said veil.

The operation is similar to that of a conventional hydrokinetic coupling device. As a reminder, it will be recalled that the turbine wheel 28 is driven by the impeller wheel thanks to the fluid contained in the housing and that, after starting the vehicle, the locking clutch 13 allows, to avoid the phenomena of sliding between the wheels 20 and 28, a connection of the driven shaft with the driving shaft, by tightening the friction disc 46, under the effect of the axial displacement of the piston 44. The locking which results therefrom allows direct drive of the driven shaft 32, typically the input shaft of a gearbox, by the casing 11 linked in rotation to the crankshaft of the vehicle engine.

Claims

1. Hydrokinetic coupling apparatus comprising a casing (11) comprising, of revolution about an axis, on the one hand, an envelope (15-18) provided with a transverse wall (16) suitable for being linked in rotation to a driving shaft and, on the other hand, an impeller or impeller (20), capable of hydrokinetically driving a turbine wheel (28) with blades, integral with a hub (35) suitable for being linked in rotation to a driven shaft (32), the impeller (20) and the turbine wheel (28) being made of shells (18-55) having blades (21-29) integral with the internal face (19-56) of the shells (18-55), in which L is the maximum width measured axially of the internal circuit available to the hydraulic fluid contained in the device, I the width measured axially in line with the portion of said circuit closest to the axis of the part furthest from the axis, and H the height measured radially of said internal circuit, characterized in that the value of the rap IJH port is less than 0.55 and the value of the w / h ratio is at most equal to 0.35.

2. hydrokinetic coupling apparatus according to claim 1, in which R (m) denotes the distance to the axis of the point of the hydraulic circuit closest to the axis and R (L) the radius of the circle on which is placed the maximum width L, characterized in that the ratio R (m) / R (L) is between 0.6 and 0.8.

3. hydrokinetic coupling device according to claim 2, in which the width I of the circuit is at a distance R (l) from the axis, characterized in that the ratio l / L is between 0.6 and 0 , 7 and the ratio R (l) / R (m) between 2.27 and 2.41.

4. hydrokinetic coupling apparatus according to claim 2, wherein the width I of the circuit is at a distance R (l) from the axis, characterized in that the ratio R (L) / R (l) is included between 0.55 and 0.75.

5. hydrokinetic coupling device according to claim 2, in which R (M) denotes the distance to the axis of the point of the hydraulic circuit furthest from the axis, characterized in that the ratio R (m) / R (M) is between 0.35 and 0.45.

6. hydrokinetic coupling apparatus according to one of claims 1 to 5, characterized in that the internal profile of the circuit is, in axial section, symmetrical with respect to a transverse plane, perpendicular to the axis.

7. hydrokinetic coupling device according to one of claims 1 to 5, characterized in that the internal profile of the circuit is, in axial section, slightly inclined on the axis so that the external wall of the shell (18 ) of the impeller (20) is generally perpendicular to the axis.

8. hydrokinetic coupling apparatus according to one of claims 1 to 5, characterized in that the impeller (20) and the turbine (28) are associated with a reactor (30) for constituting a torque converter (12).

9. hydrokinetic coupling apparatus according to claim 8, characterized in that the torque converter (12) has a central guide core (60,70,80,90,91-95) for the fluid.

10. hydrokinetic coupling apparatus according to claim 9, characterized in that the core is in three parts (61, 62,63) carried respectively by the impeller (20), the turbine (28) and the reactor (30 ).

11. hydrokinetic coupling apparatus according to claim 9, characterized in that the core is in two parts, one of which (95) is carried by the impeller (20) and the other (96) by the reactor ( 30).

12. hydrokinetic coupling apparatus according to claim 9, characterized in that the core is in one piece (70,80) carried by the impeller (20) or the turbine (28).

13. hydrokinetic coupling apparatus according to claim 12, characterized in that the core (80) is in the form of a ring folded circumferentially in accordion.

14. hydrokinetic coupling apparatus according to claim 9, characterized by the core is in one piece (90-94) carried by the reactor (30).

15. hydrokinetic coupling apparatus according to claim 14, characterized in that the core is toroidal, hollow (90) or solid (94).

16. hydrokinetic coupling apparatus according to claim 14, characterized in that the core (91) is of planar shape, being produced directly from a conformation of the reactor (30).

17. hydrokinetic coupling apparatus according to claim 14, characterized in that the core (92) is generally of planar shape and comprises an axial orientation foot by which it is secured to the blades (36) of the reactor (30) , for example by force fitting or by overmolding.

18. hydrokinetic coupling apparatus according to claim 14, characterized in that the core (93) is in the form of a ring folded circumferentially in accordion.

19. hydrokinetic coupling apparatus according to one of claims 1 to 18, characterized in that inside the envelope (15-18) is placed a locking clutch (13) intervening between the turbine ( 28) and the casing (15-18), said clutch comprising a torsional damper, a piston (44) mounted axially movable and at least one friction lining suitable for being clamped between said piston (44) and the internal face of the transverse wall (16).

20. hydrokinetic coupling apparatus according to claim 19, characterized in that the torsion damper comprises springs (54) with circumferential action interposed between two parts, guide washer (50) and web (52), the one of these parts being integral in rotation with the friction lining and the other with the turbine (28).

21. hydrokinetic coupling apparatus according to one of claims 18 or 19, taken in conjunction with claims 7 and 8, characterized in that the shell (55) of the turbine (28) is deformed in line with the clutch (13) by creating a recess in the hollow (57) and the core (60) carries a boss (67) whose shape matches that of the sag (57) by extending along it while respecting the constant passage section whatever its diameter.