Turbine assembly for hydrokinetic torque converter, and method for making the same

A turbine assembly for a hydrokinetic torque converter. The turbine assembly is rotatable about a rotational axis and hydrokinetic torque converter and comprises a first turbine component coaxial with the rotational axis, and a second turbine component non-moveably secured to the turbine component coaxially therewith. The first turbine component is formed separately from the second turbine component. The first turbine component has a plurality of first turbine blade members integrally formed therewith.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to fluid coupling devices, and more particularly to a turbine assembly for hydrokinetic torque converters, and a method for making the same.

2. Background of the Invention

Typically, a hydrokinetic torque converter includes an impeller assembly, a turbine assembly, a stator (or reactor) fixed to a casing of the torque converter, and a one-way clutch for restricting rotational direction of the stator to one direction. The turbine assembly is integrally or operatively connected with a hub linked in rotation to a driven shaft, which is itself linked to an input shaft of a transmission of a vehicle. The casing of the torque converter generally includes a front cover and an impeller shell which together define a fluid filled chamber. Impeller blades are fixed to an impeller shell within the fluid filled chamber to define the impeller assembly. The turbine assembly and the stator are also disposed within the chamber, with both the turbine assembly and the stator being relatively rotatable with respect to the front cover and the impeller shell. The turbine assembly includes a turbine shell with a plurality of turbine blades fixed to one side of the turbine shell facing the impeller blades of the impeller.

The turbine assembly works together with the impeller assembly, which is linked in rotation to the casing that is linked in rotation to a driving shaft driven by an internal combustion engine. The stator is interposed axially between the turbine assembly and the impeller assembly, and is mounted so as to rotate on the driven shaft with the interposition of the one-way clutch.

Conventionally, the turbine shell and the turbine blades are generally formed separately by stamping from steel blanks. The turbine shell is typically slotted to receive, through the slots, tabs formed on the turbine blades. After the turbine blades are located within the turbine shell, the tabs are bent or rolled over to form a mechanical attachment on the turbine shell that holds the turbine blades fixed in position.

Current hydrokinetic torque converters and methods for assembly thereof are quite complex, cumbersome and expensive. Therefore, while conventional hydrokinetic torque converters, including but not limited to those discussed above, have proven to be acceptable for vehicular driveline applications and conditions, improvements that may enhance their performance and cost are possible.

BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a turbine assembly for a hydrokinetic torque converter. The turbine assembly is rotatable about a rotational axis and comprises a first turbine component coaxial with the rotational axis, and a second turbine component non-moveably secured to the turbine component coaxially therewith. The first turbine component is formed separately from the second turbine component. The first turbine component has a plurality of first turbine blade members integrally formed therewith.

According to a second aspect of the present invention, there is provided a hydrokinetic torque converter, comprising an impeller assembly rotatable about a rotational axis, and a turbine assembly rotatable about the rotational axis and disposed axially opposite to the impeller assembly. The turbine assembly is coaxially aligned with and hydro-dynamically drivable by the impeller assembly. The impeller assembly includes an impeller shell and a plurality of impeller blades outwardly extending from the impeller shell. The turbine comprises a first turbine component coaxial with the rotational axis, and a second turbine component formed separately from and non-moveably secured to the turbine component coaxially therewith. The first turbine component has a plurality of first turbine blade members integrally formed therewith. The hydrokinetic torque converter further comprises a turbine hub rotatable about the rotational axis and non-moveably secured to one of the first turbine component and the second turbine component of the turbine assembly.

According to a third aspect of the present invention, there is provided a method for assembling a turbine assembly of a hydrokinetic torque converter. The method involves the steps of providing a first turbine component, providing a second turbine formed separately from the first turbine component, providing a plurality of fasteners each including at least one fastener arm, and non-moveably securing the second turbine component to the first turbine component by means of the fasteners such that the at least one fastener arm extending axially outward from the second turbine component through the first turbine component.

Other aspects of the invention, including apparatus, devices, systems, converters, processes, and the like which constitute part of the invention, will become more apparent upon reading the following detailed description of the exemplary embodiments.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S) AND EMBODIED METHOD(S) OF THE INVENTION

Reference will now be made in detail to exemplary embodiments and methods of the invention as illustrated in the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the drawings. It should be noted, however, that the invention in its broader aspects is not limited to the specific details, representative devices and methods, and illustrative examples shown and described in connection with the exemplary embodiments and methods.

This description of exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “upper”, “lower”, “right”, “left”, “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship. Additionally, the word “a” and “an” as used in the claims means “at least one” and the word “two” as used in the claims means “at least two”.

A first exemplary embodiment of a hydrokinetic torque coupling device is generally represented inFIG. 1by reference numeral10. The hydrokinetic torque coupling device10is intended to couple driving and driven shafts, for example in a motor vehicle. In this case, the driving shaft is an output shaft of an internal combustion engine (not shown) of the motor vehicle and the driven shaft is connected to an automatic transmission (not shown) of the motor vehicle.

The hydrokinetic torque coupling device10comprises a sealed casing12filled with a fluid, such as oil or transmission fluid, and rotatable about a rotational axis X of rotation, a hydrokinetic torque converter14disposed in the casing12, a lock-up clutch15and a torsional vibration damper (also referred to herein as a damper assembly)16also disposed in the casing12. The torsional vibration damper assembly16is mounted to the torque converter14. The sealed casing12, the torque converter14, the lock-up clutch15and the torsional vibration damper16are all rotatable about the rotational axis X. The drawings discussed herein show half-views, that is, a cross-section of the portion or fragment of the hydrokinetic torque coupling device10above rotational axis X. As is known in the art, the device10is symmetrical about the rotational axis X. Hereinafter the axial and radial orientations are considered with respect to the rotational axis X of the torque coupling device10. The relative terms such as “axially,” “radially,” and “circumferentially” are with respect to orientations parallel to, perpendicular to, and circularly around the rotational axis X, respectively.

The sealed casing12according to the first exemplary embodiment as illustrated inFIG. 1includes a first casing shell17, and a second casing shell18disposed coaxially with and axially opposite to the first casing shell17. The first and second casing shells17,18are non-movably (i.e., fixedly) interconnected and sealed together about their outer peripheries, such as by weld19. The second casing shell18is non-movably (i.e., fixedly) connected to the driving shaft, more typically to a flywheel (not shown) that is non-rotatably fixed to the driving shaft, so that the casing12turns at the same speed at which the engine operates for transmitting torque. Specifically, in the illustrated embodiment ofFIG. 1the casing12is rotatably driven by the internal combustion engine and is non-rotatably coupled to the flywheel thereof, such as with studs13. As shown inFIG. 1, the studs13are fixedly secured, such as by welding, to the first casing shell17. Each of the first and second casing shells17,18are integral or one-piece and may be made, for example, by press-forming one-piece metal sheets.

The torque converter14comprises an impeller assembly (sometimes referred to as the pump or impeller wheel)20, a turbine assembly (sometimes referred to as the turbine wheel)22, and a stator assembly (sometimes referred to as the reactor)24interposed axially between the impeller assembly20and the turbine assembly22. The impeller assembly20, the turbine assembly22, and the stator assembly24are coaxially aligned with one another and the rotational axis X. The impeller assembly20, the turbine assembly22, and the stator assembly24collectively form a torus. The impeller assembly20and the turbine assembly22may be fluidly coupled to one another in operation as known in the art. The torque coupling device10also includes a substantially annular turbine (or output) hub28(as best shown inFIG. 1) rotatable about the rotational axis X, which is arranged to non-rotatably couple together the driven shaft and the turbine assembly22. A sealing member29, mounted to a radially inner peripheral surface of the turbine hub28, creates a seal at the interface of the transmission input shaft and the turbine hub28.

The impeller assembly20includes a substantially annular, semi-toroidal (or concave) impeller shell21, a substantially annular impeller core ring26, and a plurality of impeller blades25fixedly (i.e., non-moveably) attached, such as by brazing, to the impeller shell21and the impeller core ring26. Thus, a portion of the second casing shell18of the casing12also forms and serves as the impeller shell21of the impeller assembly20. Accordingly, the impeller shell21sometimes is referred to as part of the casing12. The impeller assembly20, including the impeller shell21, the impeller core ring26and the impeller blades25, is non-rotatably secured to the first casing shell18and hence to the drive shaft (or flywheel) of the engine to rotate at the same speed as the engine output.

The turbine assembly22, as best shown inFIGS. 1-4, comprises a substantially annular, semi-toroidal (or concave) turbine shell30rotatable about the rotational axis X, and a plurality of turbine blades32fixedly (i.e., non-moveably) secured to the turbine shell30and outwardly extending from the turbine shell30so as to face the impeller blades25of the impeller assembly20. The turbine shell30of the turbine assembly22is non-movably (i.e., fixedly) secured to the turbine hub28by appropriate means, such as by rivets27or welding.

Furthermore, the turbine assembly22comprises a first turbine component34rotatable about the rotational axis X, and a second turbine component36formed separately from and non-moveably secured to the first turbine component34coaxially therewith, as best shown inFIGS. 2-4, 7 and 8. As illustrated inFIGS. 2-4, 7A and 8A, the first turbine component34includes a substantially annular first turbine shell member38and a plurality of first turbine blade members40integrally formed therewith and outwardly extending from the first turbine shell member38so as to face the impeller blades25of the impeller assembly20. Preferably, the first turbine shell member38and the first turbine blade members40are made of a single or unitary (i.e., one-piece) component, but may be separate components fixedly (i.e., non-moveably) connected together. The first turbine shell member38has a substantially semi-toroidal radially outer portion42and a substantially annular mounting portion44located radially within the radially outer portion42of the first turbine shell member38. The mounting portion44of the first turbine shell member38is provided with a plurality of equiangularly circumferentially spaced holes45. The first turbine shell member38is fixedly secured to the turbine hub28by the rivets27extending through the holes45in the mounting portion44of the first turbine shell member38.

The radially outer portion42of the first turbine shell member38has a substantially annular, semi-toroidal (i.e., concave) inner surface43aand a substantially annular support surface43blocated radially within the inner surface43aof the radially outer portion42of the first turbine shell member38. Both the inner surface43aand the support surface43bof the radially outer portion42of the first turbine shell member38face the impeller assembly20. As best shown inFIG. 2, the turbine blade members40are integrally formed on and outwardly extend from the inner surface43aof the radially outer portion42of the first turbine shell member38of the first turbine component34of the turbine assembly22. The radially outer portion42of the first turbine shell member38is also provided with a plurality of equiangularly circumferentially spaced holes39, as best shown inFIGS. 2 and 3.

As further illustrated inFIGS. 2-4, 7 and 8, the second turbine component36is formed separately from the first turbine component34and includes a substantially annular second turbine shell member46, and a plurality of second turbine blade members48integrally formed therewith and outwardly extending from an annular, substantially semi-toroidal (i.e., concave) inner surface47Fof the second turbine shell member46so as to face the impeller blades25of the impeller assembly20. Preferably, the second turbine shell member46and the second turbine blade members48are made of a single or unitary (i.e., one-piece) component, but may be separate components fixedly (i.e., non-moveably) connected together.

An annular outer surface47Rof the second turbine shell member46of the second turbine component36non-moveably engages the support surface43bof the radially outer portion42the first turbine component34by appropriate means known in the art, such as adhesive bonding, friction welding, snap-on connection, etc. In other words, the second turbine shell member46of the second turbine component36overlaps the first turbine shell member38of the first turbine component34. The second turbine shell member46of the second turbine component36non-moveably engages the first turbine shell member38of the first turbine component34so as to define together the turbine shell30of the turbine assembly22. An annular rear surface43Rof the first turbine shell member38faces away from the annular outer surface47Rof the second turbine shell member46of the second turbine component36.

The first turbine component34and the second turbine component36are formed separately, and then non-moveably, coaxially assembled together so as to form the turbine assembly22. As best illustrated inFIGS. 4 and 7A, each of the first turbine blade members40is oriented adjacent to one of the second turbine blade members48so as to define together the turbine blade32of the turbine assembly22. Specifically, radially inner distal ends41dof the first turbine blade members40are disposed adjacent to or engaged with radially outer distal ends49dof the second turbine blade members48. Also, the second turbine shell member46of the second turbine component36non-moveably engages the first turbine shell member38of the first turbine component34so as to define together the turbine shell30of the turbine assembly22.

According to the present invention, the first and second turbine components34and36, respectively, are made by casting in aluminum or magnesium alloys or by molding in a thermoplastic or thermosetting plastic materials, or they may be formed by plastic deformation of a metallic material such as sheet steel. Preferably, the first turbine component34is made by casting of an aluminum or magnesium alloy, while the second turbine component36is made by injection molding of a thermoplastic polymer, such as a polyetheretherketone (PEEK) thermoplastic polymer, a polytetrafluoroethylene (PTFE) based material, or a thermosetting polymer. PEEK polymer provides fatigue and chemical resistance, can operate at high temperatures and retains outstanding mechanical properties at continuous-use temperatures up to 240° C. (464° F.), allowing it to replace metal even in the most severe end-use environments. Glass fiber-reinforced and carbon fiber-reinforced grades of PEEK provide a wide range of performance options. For example, the second turbine component36made be made of a glass fiber and carbon fiber reinforced PEEK, such as the KetaSpire® KT-880 CF30 polyetheretherketone, which is a high flow, 30% carbon fiber reinforced grade of polyetheretherketone. In other words, the first turbine component34and the second turbine component36could be made of the same or different materials having different mechanical characteristics, such as a specific strength, specific weight, density, modulus of elasticity, etc.

Moreover, as best shown inFIGS. 7B and 7C, the first turbine component34and the second turbine component36have a variable thickness. In fact, both the first turbine shell member38and the first turbine blade members40of the first turbine component34have a variable thickness, as best shown inFIGS. 7B and 8B. Similarly, both the second turbine shell member46and the second turbine blade members48of the second turbine component36have a variable thickness, as best shown inFIGS. 7B and 7C. For instance, an axial thickness k1of the radially outer portion42of the first turbine shell member38in a region of the inner surface43ais larger than an axial thickness k2of the radially outer portion42of the first turbine shell member38in a region of the support surface43b, as best shown inFIG. 7B.

Furthermore, as best illustrated inFIG. 7B, the axial thickness k1of the radially outer portion42of the first turbine shell member38in the region of the inner surface43asubstantially equals the sum of the axial thickness k2of the radially outer portion42in the region of the support surface43band an axial thickness k3of the second turbine shell member46(shown inFIG. 7C). Also, an axial thickness t1of a radially outer proximal end41pof the first turbine blade members40is larger than an axial thickness t2of the radially inner distal ends41dof the first turbine blade members40, as best shown inFIG. 7B. Similarly, an axial thickness t3of a radially inner proximal end49pof the second turbine blade members48is larger than an axial thickness t4of the radially outer distal ends49dof the second turbine blade members48, as best shown inFIG. 7C.

Accordingly, the molded turbine assembly22can have variation in thickness, and be formed in a very particular form and shape. Also, the molded turbine assembly can have reinforcing ribs. Thus, with the molded turbine assembly of the present invention there is a possibility for mass optimization by putting the thickness where it is needed for strength and reducing the thickness where it is not needed, where stress and deformation are low.

The second turbine component36further includes a plurality of circumferentially (or angularly) spaced snap fasteners50, as best shown inFIGS. 3, 6, 8A and 8C. The snap fasteners50are configured to axially extend through the holes39in the radially outer portion42of the first turbine shell member38in order to fixedly (i.e., non-moveably) secured the second turbine shell member46to the first turbine shell member38.

Each of the snap fasteners50according to the first exemplary embodiment of the present invention, as best shown inFIG. 6B, includes a resilient cylindrical, hollow snap arm (or fastener arm)52integrally formed with a base portion56of the second turbine shell member46on the annular outer surface47Rthereof so as to extend axially outward from the outer surface47Rof the second turbine shell member46toward the first turbine shell member38of the first turbine component34. Preferably, the cylindrical snap arm52extends substantially perpendicularly to the outer surface47Rof the second turbine shell member46, or substantially parallel to the rotational axis X. An axially distal free end of the cylindrical snap arm52is formed with one or more arc-shaped barbs or ledges54extending radially outwardly from the axially distal end of the snap arm52. According to the first exemplary embodiment of the present invention, each of the snap fasteners50has two radially opposite barbs54, as best shown inFIGS. 3B and 6B. Moreover, as best shown inFIG. 8C, each of the barbs54has an outwardly tapered exterior end surface55forming a ramp surface. The opposite barbs54on the axially distal end of each of the snap arms52are similar but are oriented in opposite directions so as to face one another. The axially distal end of the cylindrical snap arm52is elastically deformable in the radial direction.

The second turbine shell member46is fixedly (i.e., non-moveably) secured to the first turbine shell member38by the male snap fasteners50extending through the holes39in the radially outer portion42of the first turbine shell member38.

A method for assembling the turbine assembly22by securing the second turbine component36to the first turbine component34is as follows. First, the snap arms52of the snap fasteners50of the second turbine component36are inserted into the holes39of the first turbine component34. Then, the snap fasteners50are pressed through or into the holes39(manually or by machine), causing the snap arms52of the snap fasteners50to resiliently deform inwardly as a result of the pressure applied by edges of the holes39against the tapered exterior end surfaces55of the opposite barbs54. During insertion, the outwardly inclined tapered exterior end surfaces55of the opposite barbs54also act to guide the snap arms52into the holes39. The snap arms52of the snap fasteners50advance through the holes39until the snap arms52spring back to their original position as soon as the opposite barbs54pass (or clear) the edges of the holes39, i.e. until the barbs54of the snap fasteners50of the second turbine component36positively engage the annular rear surface43Rof the first turbine shell member38so that the annular outer surface47Rof the second turbine shell member46engages the annular support surface43bof the radially outer portion42of the first turbine shell member38.

Various modifications, changes, and alterations may be practiced with the above-described embodiment, including but not limited to the additional embodiments shown inFIGS. 9-30. In the interest of brevity, reference characters inFIGS. 9-30that are discussed above in connection with Figs.FIGS. 1-8Care not further elaborated upon below, except to the extent necessary or useful to explain the additional embodiments ofFIGS. 9-30. Modified components and parts are indicated by the addition of a hundred digits to the reference numerals of the components or parts.

In a hydrokinetic torque coupling device110of a second exemplary embodiment illustrated inFIGS. 9-16B, the second turbine component36of the turbine assembly22is replaced by a second turbine component136of a turbine assembly122. The hydrokinetic torque coupling device110ofFIGS. 9-16Bcorresponds substantially to the hydrokinetic torque coupling device10ofFIGS. 1-8C, and only the portions of the second turbine component136which differ will therefore be explained in detail below. In the second exemplary embodiment of the present invention illustrated inFIGS. 9-16B, the second turbine component136includes two or more equiangularly circumferentially (or angularly) spaced snap fasteners150, as best shown inFIGS. 11, 14, 16A and 16B. The second turbine shell member146of the second turbine component136non-moveably engages first turbine shell member38of a first turbine component34so as to define together a turbine shell130of the turbine assembly122.

The snap fasteners150are configured to axially extend through the holes39in the radially outer portion42of the first turbine shell member38in order to fixedly (i.e., non-moveably) secure the second turbine shell member146to the first turbine shell member38.

Each of the snap fasteners150according to the second exemplary embodiment of the present invention includes one or more resilient snap arms152integrally formed with a base portion156of a second turbine shell member146on an annular outer surface147Rthereof so as to extend axially outwardly from the outer surface147Rof the second turbine shell member146toward the first turbine shell member38of the first turbine component34. Preferably, the snap arms152extend substantially perpendicular to the outer surface147Rof the second turbine shell member146, or substantially parallel to the rotational axis X. According to the second exemplary embodiment of the present invention, the snap fastener150includes four snap arms152oriented diagonally opposite to one another, as best shown inFIGS. 11A and 14. However, the snap fastener150may include more or fewer than four snap arms152.

An axially distal free end of each of the snap arms152is formed with a barb or ledge154extending outwardly from the axially distal end of the snap arm152. Moreover, as best shown inFIGS. 16A and 16B, each of the barbs154has an outwardly tapered exterior end surface155forming a ramp surface. The barbs154on the axially distal ends of the snap arms152are similar to but oriented in opposite directions so as to face away from each other. The snap arms152are elastically deformable in the radial direction.

The second turbine shell member146of the second turbine component136is fixedly (i.e., non-moveably) secured to the first turbine shell member38of the first turbine component34by the snap fasteners150extending through the holes39in the radially outer portion42of the first turbine shell member38.

A method of securing the second turbine component136to the first turbine component34is as follows. First, the snap arms152of the snap fasteners150of the second turbine component136are inserted into the holes39of the first turbine component34. Then, the snap fasteners150are pressed into the holes39(by applying an axial force to the second turbine component136toward the first turbine component34or to the first turbine component34toward the second turbine component136), causing the snap arms152of the snap fasteners150to resiliently deform inwardly as a result of the pressure applied by edges of the holes39against the tapered exterior end surfaces155of the barbs154. This force can be applied either manually or using a machine. During insertion, the outwardly inclined tapered exterior end surfaces155of the barbs154also act to guide the snap arms152into the holes39. The snap arms152of the snap fasteners150advance through the holes39until the snap arms152spring back to their original or undeformed position as soon as the barbs154pass (or clear) the edges of the holes39, i.e. until the barbs154of the snap fasteners150of the second turbine component136positively engage an annular rear surface43Rof the first turbine shell member38so that the annular outer surface147Rof the second turbine shell member146engages the annular support surface43bof the radially outer portion42of the first turbine shell member38.

In a hydrokinetic torque coupling device210of a third exemplary embodiment illustrated inFIGS. 17-26, the second turbine component36of the turbine assembly22is replaced by a second turbine component236of a turbine assembly222, and further comprises two or more of snap fasteners250. The hydrokinetic torque coupling device210ofFIGS. 17-26corresponds substantially to the hydrokinetic torque coupling device10ofFIGS. 1-8C, and only the portions of the second turbine component236and the snap fasteners250, which differ, will therefore be explained in detail below. In the third exemplary embodiment of the present invention illustrated inFIGS. 17-26, a base portion256of a second turbine shell member246of the second turbine component236includes a plurality of circumferentially (or angularly) mounting holes258complementary to and having substantially the same diameter as holes39of a first turbine component34.

The snap fasteners250, as best shown inFIG. 20, are formed separately from the first and second turbine components34and236, respectively. Accordingly, the snap fasteners250may be made of a material different from the material(s) of the first and second turbine components34and236, respectively. Each of the snap fasteners250according to the third exemplary embodiment of the present invention includes a circular base251, and one or more resilient snap arms252which extend axially outward from the base251, as best shown inFIG. 20. The one or more resilient snap arms252of each of the snap fasteners250are configured to axially extend through the holes39in the radially outer portion42of the first turbine shell member38and the mounting holes258in the second turbine shell member246in order to fixedly (i.e., non-moveably) secure the second turbine shell member246to the first turbine shell member38. In an assembled condition, the snap arms252extend axially from the second turbine shell member146toward the first turbine shell member38. Preferably, the snap arms252extend substantially perpendicularly to the base251and an outer surface247Rof the second turbine shell member246, or substantially parallel to the rotational axis X. According to the third exemplary embodiment of the present invention, each of the snap fasteners250includes four snap arms252oriented diagonally opposite to one another, as best shown inFIGS. 20 and 23. However, the snap fastener250may include more or fewer than four snap arms252.

An axially distal free end of each of the snap arms252is formed with a barb or ledge254extending radially outwardly from the axially distal end of the snap arm252. Moreover, as best shown inFIG. 20, each of the barbs254has an outwardly tapered exterior end surface255forming a ramp surface. The barbs254on the axially distal ends of the snap arms252are similar to but are oriented in opposite directions so as to face one another. The snap arms252are elastically deformable in the radial direction.

The second turbine shell member246of the second turbine component236is fixedly (i.e., non-moveably) secured to the first turbine shell member38of the first turbine component34by the snap fasteners250extending through the holes39in the radially outer portion42of the first turbine shell member38and the mounting holes258in the second turbine shell member246.

A method of securing the second turbine component236to the first turbine component34is as follows. First, the second turbine shell member246of the second turbine component236is brought in contact with the first turbine shell member38of the first turbine component34so that the mounting holes258in the second turbine shell member246are aligned with the holes39in the radially outer portion42of the first turbine shell member38. Then the snap arms252of the snap fasteners250are inserted into the mounting holes258of the second turbine component236. Then, the snap fasteners250are pressed into the mounting holes258(by applying an axial force to the bases251of the snap fasteners250toward the holes39of the first turbine component34), causing the snap arms252of the snap fasteners250to resiliently deform inwardly as a result of the pressure applied by edges of the mounting holes258and the holes39against the tapered exterior end surfaces255of the barbs254. This force can be applied either manually or using a machine. During insertion, the outwardly inclined tapered exterior end surfaces255of the barbs254also act to guide the snap arms252into the mounting holes258and the holes39. The snap arms252of the snap fasteners250advance through the mounting holes258and the holes39until the snap arms252spring back to their original or undeformed position as soon as the barbs254pass (or clear) the edges of the holes39, i.e. until the barbs254of the snap fasteners250of the second turbine component236positively engage an annular rear surface43Rof the first turbine shell member38so that the annular outer surface247Rof the second turbine shell member246engages the annular support surface43bof the radially outer portion42of the first turbine shell member38.

In a hydrokinetic torque coupling device310of a fourth exemplary embodiment illustrated inFIGS. 26-33, the second turbine component36of the turbine assembly22is replaced by a second turbine component336of a turbine assembly322. The hydrokinetic torque coupling device310ofFIGS. 26-33corresponds substantially to the hydrokinetic torque coupling device10ofFIGS. 1-8C, and only the portions of the second turbine component336, which differ, will therefore be explained in detail below. In the fourth exemplary embodiment of the present invention illustrated inFIGS. 26-33, the second turbine component336includes two or more of circumferentially (or angularly) spaced snap fasteners350, as best shown inFIGS. 26, 28A, 28B and 33. The snap fasteners350are configured to fixedly (i.e., non-moveably) secure the first turbine component34of the turbine assembly322to the second turbine component336thereof. The second turbine shell member346of the second turbine component336non-moveably engages first turbine shell member38of a first turbine component34so as to define together a turbine shell330of the turbine assembly322. Moreover, the snap fasteners350are configured to axially extend through the holes39in the radially outer portion42of the first turbine shell member38in order to fixedly (i.e., non-moveably) secure the second turbine shell member346to the first turbine shell member38.

Each of the snap fasteners350according to the fourth exemplary embodiment of the present invention includes a resilient hollow cylindrical snap arm352and a slotted ring353. The cylindrical snap arm352is integrally formed with a base portion356of a second turbine shell member346on an annular outer surface347Rthereof so as to extend axially outward from the outer surface347Rof the second turbine shell member346toward the first turbine shell member38of the first turbine component34. Preferably, the cylindrical snap arm352extends substantially perpendicularly to the outer surface347Rof the second turbine shell member346, or substantially parallel to the rotational axis X. An axially distal free end of the cylindrical snap arm352is formed with one or more arc-shaped barbs or ledges354extending radially outwardly from the axially distal end of the snap arm352. According to the fourth exemplary embodiment of the present invention, each of the snap fasteners350has two radially opposite barbs354, as best shown inFIGS. 28B, 31B and 33. Moreover, as best shown inFIG. 33, each of the barbs354has an outwardly tapered exterior end surface355forming a ramp surface. The opposite barbs354on the axially distal end of each of the snap arms352are similar but are oriented in opposite directions so as to face one another. The axially distal end of the cylindrical snap arm352is elastically deformable in the radial direction.

Each of the slotted rings353is a radially expandable slotted ring (i.e., formed with a slot353ashown inFIG. 31B), such as a conventional snap ring or C-ring well known to those skilled in the art, and has axially opposite flat surfaces. As best shown inFIG. 33, each of the slotted rings353is maintained radially over and around the cylindrical snap arm352within the barbs354and seated upon and around the cylindrical snap arm352of the snap fastener350. As illustrated, the slotted rings353are disposed between the rear surface43Rof the first turbine shell member38and the barbs354of the snap arms352. The slotted rings353increase the contact surface for axial retention. The slotted rings353can also be “load” snap rings configured to exert an axial load (or force) to stack (or press) the first and second turbine components34and336, respectively, together.

A method of securing the second turbine component336to the first turbine component34is as follows. First, the snap arms352of the snap fasteners350on the second turbine component336are inserted into the holes39of the first turbine component34. Then, the snap arms352are pressed over the holes39(manually or by machine), causing the snap arms352of the snap fasteners350to resiliently deform inwardly as a result of the pressure applied by edges of the holes39against the tapered exterior end surfaces355of the opposite barbs354. During insertion, the outwardly inclined tapered exterior end surfaces355of the opposite barbs354also act to guide the snap arms352into the holes39. The snap arms352of the snap fasteners350advance through the holes39until the snap arms352spring back to their original or undeformed position as soon as the opposite barbs354pass (or clear) the edges of the holes39. Next, the slotted rings353are mounted over and around the cylindrical snap arm352between the rear surface43Rof the first turbine shell member38and the barbs354of the snap arms352. In this position, the barbs354of the snap fasteners350of the second turbine component336positively engage the flat surfaces of the slotted rings353, while the opposite flat surfaces of the slotted rings353engage the annular rear surface43Rof the first turbine shell member38so that the annular outer surface347Rof the second turbine shell member346engages the annular support surface43bof the radially outer portion42of the first turbine shell member38.

In a hydrokinetic torque coupling device410of a fifth exemplary embodiment illustrated inFIGS. 34-42, the second turbine component36of the turbine assembly22is replaced by a second turbine component436of a turbine assembly422. The hydrokinetic torque coupling device410ofFIGS. 34-42corresponds substantially to the hydrokinetic torque coupling device10ofFIGS. 1-8C, and only the portions of the second turbine component436, which differ, will therefore be explained in detail below. In the fourth exemplary embodiment of the present invention illustrated inFIGS. 34-42, the second turbine component436includes two or more of circumferentially (or angularly) spaced fasteners450, as best shown in FIGS.34,39and40. The fasteners450are configured to fixedly (i.e., non-moveably) secure a first turbine component34of the turbine assembly422to the second turbine component436thereof. The second turbine shell member446of the second turbine component436non-moveably engages a first turbine shell member38of the first turbine component34so as to define together a turbine shell430of the turbine assembly422. Moreover, the fasteners450axially extend through the holes39in the radially outer portion42of the first turbine shell member38in order to fixedly (i.e., non-moveably) secure the second turbine shell member446to the first turbine shell member38.

Each of the fasteners450according to the fifth exemplary embodiment of the present invention includes a hollow cylindrical fastener arm452and a slotted ring453. The cylindrical fastener arm452is integrally formed with a base portion456of a second turbine shell member446on an annular outer surface447Rthereof so as to extend axially outward from the outer surface447Rof the second turbine shell member446toward the first turbine shell member38of the first turbine component34. Preferably, the cylindrical fastener arm452extends substantially perpendicular to the outer surface447Rof the second turbine shell member446, or substantially parallel to the rotational axis X. An axially distal free end452aof the cylindrical fastener arm452is formed with an annular groove454, as best shown inFIGS. 36B and 42. Moreover, as best shown inFIG. 42, the axially distal free end452aof the cylindrical fastener arms452has an outwardly tapered exterior end surface455.

Each of the slotted rings453is a radially expandable slotted ring (i.e., formed with a slot453ashown inFIGS. 35 and 36A), such as a conventional snap ring or C-ring well known to those skilled in the art, and has axially opposite flat surfaces. As best shown inFIG. 40, each of the slotted rings453is maintained radially over and around one of the cylindrical fastener arms452and at least partially seated (disposed) in the annular groove454of the fastener450. As illustrated, the slotted rings453are disposed between the rear surface43Rof the first turbine shell member38and the axially distal free ends452aof the cylindrical fastener arms452. The slotted rings453are provided to retain axially the first and second turbine components34and436, respectively, together. The slotted rings453can also be a “load” snap rings configured to exert an axial load (or force) to stack (or press) the first and second turbine components34and436, respectively, together.

A method of securing the second turbine component436to the first turbine component34is as follows. First, the fastener arms452of the fasteners450on the second turbine component436are inserted into the holes39of the first turbine component34. Then, the fastener arms452are pressed over the holes39(manually or by machine), until the axially distal free ends452aof the fastener arms452pass (or clear) the edges of the holes39. Next, the slotted snap rings453are mounted into the annular groove454of the fastener arms452. In this position, the slotted snap rings453of the fasteners450positively engage the annular rear surface43Rof the first turbine shell member38so that the annular outer surface447Rof the second turbine shell member446engages the annular support surface43bof the radially outer portion42of the first turbine shell member38.

In a hydrokinetic torque coupling device510of a sixth exemplary embodiment illustrated inFIGS. 43-51, the turbine assembly22is replaced by a turbine assembly522. The hydrokinetic torque coupling device510ofFIGS. 43-51corresponds substantially to the hydrokinetic torque coupling device10ofFIGS. 1-8C, and only the portions of the turbine assembly522, which differ, will therefore be explained in detail below.

The turbine assembly522of the sixth exemplary embodiment comprises a first turbine component534rotatable about the rotational axis X, and a second turbine component536non-moveably secured to the first turbine component534coaxially therewith, as best shown inFIGS. 43-45, 48 and 49. As illustrated, the first turbine component534includes a substantially annular first turbine shell member538and a plurality of first turbine blade members40integrally formed therewith and outwardly extending from the first turbine shell member538so as to face the impeller blades25of the impeller assembly20. Preferably, the first turbine shell member538and the first turbine blade members40are made of a single or unitary component, but may be separate components fixedly (i.e., non-moveably) connected together.

The first turbine shell member538has a substantially annular, semi-toroidal (i.e., concave) inner surface543aand a substantially annular support surface543blocated radially within the inner surface543aof the first turbine shell member538. Both the inner surface543aand the support surface543bof the first turbine shell member538are facing the impeller assembly20. As best shown inFIG. 44, the turbine blade members40are integrally formed on and outwardly extend from the inner surface543aof the first turbine shell member538of the first turbine component534of the turbine assembly522. A radially inner peripheral edge542of the first turbine shell member538is provided with a plurality of circumferentially spaced, generally U-shaped cut-outs539, as best shown inFIGS. 44 and 45.

As further illustrated inFIGS. 44 and 45, the second turbine component536includes a substantially annular second turbine shell member546and a plurality of second turbine blade members48integrally formed therewith and outwardly extending from the second turbine shell member546so as to face the impeller blades25of the impeller assembly20. Preferably, the second turbine shell member546and the second turbine blade members48are made of a single or unitary component, but may be separate components fixedly (i.e., non-moveably) connected together.

The second turbine shell member546has a substantially annular, semi-toroidal radially outer portion546o, a substantially annular base portion556located radially within the radially outer portion546o, and a substantially annular mounting portion546mlocated radially within the base portion556and the radially outer portion546oof the second turbine shell member546. The second turbine blade members48are integrally formed with the radially outer portion546oof the second turbine shell member546and outwardly extend from an annular, substantially semi-toroidal (i.e., concave) inner surface547Fof the second turbine shell member546. The mounting portion546mof the second turbine shell member546is provided with a plurality of circumferentially spaced holes545. The second turbine shell member546is fixedly secured to the turbine hub28by the rivets27extending through the holes545in the mounting portion546mof the second turbine shell member546.

In the sixth exemplary embodiment of the present invention illustrated inFIGS. 43-51, the second turbine component536includes two or more of equiangulrly circumferentially (or angularly) spaced fasteners550, as best shown inFIGS. 43, 47, 48 and 49. The fasteners550are configured to fixedly (i.e., non-moveably) secure the first turbine component534of the turbine assembly522to the second turbine component536thereof. A second turbine shell member546of the second turbine component536non-moveably engages a first turbine shell member538of the first turbine component534so as to define together a turbine shell530of the turbine assembly522.

Each of the fasteners550according to the sixth exemplary embodiment of the present invention includes a fastener arm552integrally formed with the base portion556of the second turbine shell member546on an annular outer surface547Rthereof so as to extend axially outward from the outer surface547Rof the second turbine shell member546toward the first turbine shell member538of the first turbine component534. Preferably, the fastener arm552extends substantially perpendicular to the outer surface547Rof the second turbine shell member546, or substantially parallel to the rotational axis X. Moreover, the fastener arms552are configured to axially extend through equiangularly disposed U-shaped cut-outs539formed in the radially inner peripheral edge542of the first turbine shell member538in order to non-rotatably secure the second turbine component536relative to the first turbine component534. Specifically, a circumferential length of each of the fastener arms552substantially equals the circumferential length of each of the U-shaped cut-outs539. Accordingly, as the fastener arms552of the second turbine component536extend through the U-shaped cut-outs539in the first turbine component534, the relative angular movement between the first turbine component534and the second turbine component536is blocked.

Furthermore, an axially distal free end552aof each of the fastener arms552is formed with a circumferentially extending groove554open radially outwardly from the rotational axis X, as best shown inFIGS. 51 and 52.

The turbine assembly522according to the sixth exemplary embodiment of the present invention further comprises a single slotted (or snap) ring553substantially coaxial (or concentric) with the rotational axis X. The slotted ring553is a radially expandable slotted ring (i.e., formed with a slot553ashown inFIG. 45), such as a conventional snap ring or C-ring well known to those skilled in the art, and has axially opposite flat surfaces. As best shown inFIGS. 43, 48, 49 and 50, the slotted ring553is maintained radially over the fastener arms552and at least partially seated (disposed) in the grooves554of the fastener arms552. As illustrated, the snap ring553is disposed between the rear surface543Rof the first turbine shell member538and the axially distal free ends552aof the fastener arms552. The snap ring553is provided to retain axially the first and second turbine components534and536, respectively, together. Thus, the first turbine component534and the second turbine component536are fixedly (i.e., non-moveably) secured one to another. The snap ring553can also be a “load” snap rings configured to exert an axial load (or force) to stack (or press) the first and second turbine components534and536, respectively, together.

A method of securing the second turbine component536to the first turbine component534is as follows. First, the fastener arms552of the fasteners550on the second turbine component536are inserted into the cut-outs539of the first turbine component534until the axially distal free ends552aof the fastener arms552with the grooves554pass (or clear) the edges of the cut-outs539. Next, the slotted snap ring553is mounted into the grooves554of fastener arms552. In this position, the slotted snap ring553positively engage the annular rear surface543Rof the first turbine shell member538so that the annular outer surface547Rof the second turbine shell member546engages the annular support surface543bof the radially outer portion542of the first turbine shell member538.

In a hydrokinetic torque coupling device610of a seventh exemplary embodiment illustrated inFIGS. 52-62, the turbine assembly522is replaced by a turbine assembly622. The hydrokinetic torque coupling device610ofFIGS. 52-62corresponds substantially to the hydrokinetic torque coupling device510ofFIGS. 43-51, and only the portions of the turbine assembly622, which differ, will therefore be explained in detail below.

The turbine assembly622of the seventh exemplary embodiment comprises a first turbine component634rotatable about the rotational axis X, and a second turbine component636non-moveably secured to the first turbine component634coaxially therewith, as best shown inFIGS. 52-54. As illustrated, the first turbine component634includes a substantially annular first turbine shell member638and a plurality of first turbine blade members40integrally formed therewith and outwardly extending from the first turbine shell member638so as to face the impeller blades25of the impeller assembly20. Preferably, the first turbine shell member638and the first turbine blade members40are made of a single or unitary component, but may be separate components fixedly (i.e., non-moveably) connected together.

The first turbine shell member638has a substantially annular, semi-toroidal (i.e., concave) inner surface643aand a substantially annular support surface643blocated radially within the inner surface643aof the first turbine shell member638. Both the inner surface643aand the support surface643bof the first turbine shell member638are facing the impeller assembly20. As best shown inFIG. 53, the turbine blade members40are integrally formed on and outwardly extend from the inner surface643aof the first turbine shell member638of the first turbine component634of the turbine assembly622. A radially inner peripheral edge642of the first turbine shell member638is provided with a plurality of circumferentially spaced pairs of protrusions, each pair including first and second protrusions6391and6392, respectively. The pairs are equiangularly disposed about the edge642. Each of the first and second protrusions6391and6392extending radially inwardly from the radially inner peripheral edge642of the first turbine shell member638and integrally formed with the first turbine shell member638, as best shown inFIGS. 53 and 54. Moreover, the radially inner peripheral edge642of the first turbine shell member638is coaxial (or concentric) with the rotational axis X. According to the seventh exemplary embodiment, a circumferential distance between the first and second protrusions6391and6392is substantially bigger that a circumferential distance between the first protrusions6391or between the second protrusions6392, as best shown inFIGS. 53 and 54.

As further illustrated inFIGS. 52-54, the second turbine component636includes a substantially annular second turbine shell member646and a plurality of second turbine blade members48integrally formed therewith and outwardly extending from the second turbine shell member646so as to face the impeller blades25of the impeller assembly20. Preferably, the second turbine shell member646and the second turbine blade members48are made of a single or unitary component, but may be separate components fixedly (i.e., non-moveably) connected together.

In the seventh exemplary embodiment of the present invention illustrated inFIGS. 52-61, the second turbine component636includes two or more of circumferentially (or angularly) spaced snap fasteners650, as best shown inFIGS. 52, 54, 55, 56, 58 and 61. The snap fasteners650are configured to fixedly (i.e., non-moveably) secure the first turbine component634of the turbine assembly622to the second turbine component636thereof. A second turbine shell member646of the second turbine component636non-moveably engages a first turbine shell member638of the first turbine component634so as to define together a turbine shell630of the turbine assembly622.

Each of the snap fasteners650according to the seventh exemplary embodiment of the present invention includes a resilient snap arm652integrally formed with the base portion656of the second turbine shell member646on an annular outer surface647Rthereof so as to extend axially outward from the outer surface647Rof the second turbine shell member646toward the first turbine shell member638of the first turbine component634, as best shown inFIG. 55. Preferably, the snap arms652extend substantially perpendicularly to the outer surface647Rof the second turbine shell member646, or substantially parallel to the rotational axis X. Also, each of the snap arms652extends substantially circumferentially (or angularly). In other words, each of the snap arms652is a circular arc (i.e., part of a circle) coaxial (or concentric) with the rotational axis X. Moreover, a radius of the radially inner peripheral edge642of the first turbine shell member638and a radius of a radially outer peripheral surface of each of the snap arms652are substantially equal to each other.

Furthermore, the snap arms652are configured to axially extend between the first and second protrusions6391and6392formed on the radially inner peripheral edge642of the first turbine shell member638in order to non-rotatably secure the second turbine component636relative to the first turbine component634. Specifically, a circumferential (or angular) length of each of the snap arms652substantially equals to the circumferential distance between the first and second protrusions6391and6392of the first turbine component634. Accordingly, as the snap arms652of the second turbine component636extend between the first and second protrusions6391and6392of the first turbine component634, the relative angular movement between the first turbine component634and the second turbine component636is blocked.

Furthermore, an axially distal free end652aof each of the snap arms652is formed with a barb or ledge654extending radially outwardly from the axially distal end652aof the snap arm652, as best shown inFIG. 55. Moreover, as best shown inFIG. 55, each of the barbs654has an outwardly tapered exterior end surface655forming a ramp surface. The snap arms652are elastically deformable in the radial direction. The second turbine shell member646of the second turbine component636is fixedly (i.e., non-moveably) secured to the first turbine shell member638of the first turbine component634by the snap fasteners650extending between the first and second protrusions6391and6392of the first turbine component634.

A method of securing the second turbine component636to the first turbine component634is as follows. First, the snap arms652of the snap fasteners650on the second turbine component636are inserted into spaces between the first and second protrusions6391and6392of the first turbine component634. The snap arms652are pressed toward the first turbine component634, causing the snap arms652to resiliently deform inwardly as a result of the pressure applied by the radially inner peripheral edge642of the first turbine component634against the tapered exterior end surfaces655of the barbs654of the snap fasteners650. During insertion, the outwardly inclined tapered exterior end surfaces655of the barbs654also act to guide the snap arms652into the spaces between the first and second protrusions6391and6392of the first turbine component634. The snap arms652of the snap fasteners650advance toward the first turbine component634until the snap arms652spring back to their original or undeformed position as soon as the barbs654pass (or clear) the radially inner peripheral edge642of the first turbine component634, i.e. until the barbs654of the snap fasteners650of the second turbine component636positively engage an annular rear surface643Rof the first turbine shell member638so that the annular outer surface647Rof the second turbine shell member646engages the annular support surface643bof the first turbine shell member638.

In a hydrokinetic torque coupling device of a eighth exemplary embodiment illustrated inFIGS. 63-72, the turbine assembly622is replaced by a turbine assembly722. The hydrokinetic torque coupling device ofFIGS. 63-72corresponds substantially to the hydrokinetic torque coupling device610ofFIGS. 52-62, and only the portions of the turbine assembly722, which differ, will therefore be explained in detail below.

In the eighth exemplary embodiment of the present invention illustrated inFIGS. 63-72, a second turbine component736includes two or more of circumferentially (or angularly) spaced snap fasteners750, as best shown inFIGS. 64-66, 68, 71 and 72. The snap fasteners750are configured to fixedly (i.e., non-moveably) secure a first turbine component734of the turbine assembly722to the second turbine component736thereof. A second turbine shell member746of the second turbine component736non-moveably engages a first turbine shell member738of the first turbine component734so as to define together a turbine shell of the turbine assembly722.

The turbine assembly722of the eighth exemplary embodiment comprises a first turbine component734rotatable about the rotational axis X, and a second turbine component736non-moveably secured to the first turbine component734coaxially therewith, as best shown inFIGS. 63-64 and 68-72. As illustrated, the first turbine component734includes a substantially annular first turbine shell member738and a plurality of first turbine blade members40integrally formed therewith and outwardly extending from the first turbine shell member738so as to face the impeller blades25of the impeller assembly20. Preferably, the first turbine shell member738and the first turbine blade members40are made of a single or unitary component, but may be separate components fixedly (i.e., non-moveably) connected together.

A radially inner peripheral edge742of the first turbine shell member738is provided with a plurality of circumferentially spaced pairs of protrusions, each pair including first and second protrusions7391and7392, respectively. Each of the first and second protrusions7391and7392extending radially inwardly extending from the radially inner peripheral edge742of the first turbine shell member738and integrally formed with the first turbine shell member738, as best shown inFIGS. 63 and 64. Moreover, the radially inner peripheral edge742of the first turbine shell member738is coaxial (or concentric) with the rotational axis X, as best shown inFIG. 68. According to the seventh exemplary embodiment, a circumferential distance between the first and second protrusions7391and7392is substantially bigger that a circumferential distance between the first protrusions7391or between the second protrusions7392, as best shown inFIGS. 63, 64 and 68.

As further illustrated inFIGS. 63-64 and 68-72, the second turbine component736includes a substantially annular second turbine shell member746and a plurality of second turbine blade members48integrally formed therewith and outwardly extending from the second turbine shell member746so as to face the impeller blades25of the impeller assembly20. Preferably, the second turbine shell member746and the second turbine blade members48are made of a single or unitary component, but may be separate components fixedly (i.e., non-moveably) connected together.

Each of the snap fasteners750according to the eighth exemplary embodiment of the present invention includes a resilient snap arm752integrally formed with a base portion756of the second turbine shell member746on an annular outer surface747Rthereof so as to extend axially outward from the outer surface747Rof the second turbine shell member746toward the first turbine shell member738of the first turbine component734, as best shown inFIG. 65. Preferably, the snap arms752extend substantially perpendicularly to the outer surface747Rof the second turbine shell member746, or substantially parallel to the rotational axis X. Also, each of the snap arms752extends substantially circumferentially (or angularly). In other words, each of the snap arms752is a circular arc (i.e., part of a circle) but not coaxial with the rotational axis X, as best shown inFIG. 68. Specifically, a radius R1of the radially inner peripheral edge742of the first turbine shell member738is substantially different than a radius R2of a radially outer peripheral surface of each of the snap arms752. Moreover, as best shown inFIG. 68, the radii R1and R2have different centers radially spaced from each other to a distance S.

Moreover, the snap arms752are configured to axially extend between the first and second protrusions7391and7392formed on the radially inner peripheral edge742of the first turbine shell member738in order to non-rotatably secure the second turbine component736relative to the first turbine component734. Specifically, a circumferential (or angular) length of each of the snap arms752substantially equals to the circumferential distance between the first and second protrusions7391and7392of the first turbine component734. Accordingly, as the snap arms752of the second turbine component736extend between the first and second protrusions7391and7392of the first turbine component734, the relative angular movement between the first turbine component734and the second turbine component736is blocked.

Furthermore, an axially distal free end752aof each of the snap arms752is formed with a barb or ledge754extending radially outwardly from the axially distal end752aof the snap arm752, as best shown inFIG. 65. Moreover, as best shown inFIG. 65, each of the barbs754has an outwardly tapered exterior end surface755forming a ramp surface. The snap arms752are elastically deformable in the radial direction. The second turbine shell member746of the second turbine component736is fixedly (i.e., non-moveably) secured to the first turbine shell member738of the first turbine component734by the snap fasteners750extending between the first and second protrusions7391and7392of the first turbine component734.

A method of securing the second turbine component736to the first turbine component734is as follows. First, the snap arms752of the snap fasteners750on the second turbine component736are inserted into spaces between the first and second protrusions7391and7392of the first turbine component734. The snap arms752are pressed toward the first turbine component734, causing the snap arms752to resiliently deform inwardly as a result of the pressure applied by the radially inner peripheral edge742of the first turbine component734against the tapered exterior end surfaces755of the barbs754of the snap fasteners750. During insertion, the outwardly inclined tapered exterior end surfaces755of the barbs754also act to guide the snap arms752into the spaces between the first and second protrusions7391and7392of the first turbine component734. The snap arms752advance toward the first turbine component734until the snap arms752spring back to their original or undeformed position as soon as the barbs754pass (or clear) the radially inner peripheral edge742of the first turbine component734, i.e. until the barbs754of the snap fasteners750of the second turbine component736positively engage an annular rear surface743Rof the first turbine shell member738so that the annular outer surface747Rof the second turbine shell member746engages the annular support surface743bof the first turbine shell member738. As the snap arms752are not coaxial with the rotational axis X, the deformation of the snap arms752during assembly of the turbine assembly722is less and stress and plastic deformation lower on distal ends (extremities) of the snap arms752, then during the assembly of the turbine assembly622of the seventh exemplary embodiment.

Therefore, the present invention provides a novel turbine assembly for a hydrokinetic torque converter and method for assembling thereof. The turbine assembly of the present invention has light weight and reduced inertia that both increase launching performance and reduce exhaust emissions of the engine, allows greater flexibility in design for improved mass and strength optimization compared to turbine assemblies of conventional hydrokinetic torque converters.

The foregoing description of the exemplary embodiment(s) of the present invention has been presented for the purpose of illustration in accordance with the provisions of the Patent Statutes. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. The embodiments disclosed hereinabove were chosen in order to best illustrate the principles of the present invention and its practical application to thereby enable those of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as suited to the particular use contemplated, as long as the principles described herein are followed. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains. Thus, changes can be made in the above-described invention without departing from the intent and scope thereof. It is also intended that the scope of the present invention be defined by the claims appended thereto.