VIBRATION DAMPER WITH BLADE-TYPE ELASTIC MEMBER, AND METHOD FOR MAKING THE SAME
20180363727 ยท 2018-12-20
Inventors
Cpc classification
F16H2045/0278
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16F2230/0064
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16H45/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16H2045/0205
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16F15/1336
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16F2226/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D2300/22
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F16F15/133
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A torsional vibration damper includes a torque input member including a radially oriented first side plate and at least one supporting member mounted thereto, and a unitary radially resilient output member elastically coupled to the torque input member. The resilient output member includes at least one elastic blade configured to elastically and radially engage the at least one supporting member. The elastic blade has a raceway is configured to bear the at least one supporting member. The at least one elastic blade and a blade insert non-moveably secured to the main body. The blade insert radially engages the at least one supporting member. The raceway is defined by a radially outer surface of the blade insert.
Claims
1. A torsional vibration damper, comprising: a torque input member rotatable about a rotational axis and including a radially oriented first side plate and at least one supporting member mounted thereto; and a unitary radially elastic output member pivotable relative to and elastically coupled to the torque input member; the radially elastic output member including an output hub coaxial with the rotational axis and rotatable relative the torque input member, and at least one elastic blade non-movably connected to the output hub and configured to elastically and radially engage the at least one supporting member and to elastically bend in the radial direction upon rotation of the first side plate with respect to the radially elastic output member; the at least one elastic blade defining a raceway configured to bear the at least one supporting member; the at least one elastic blade including a main body and a blade insert non-moveably secured to the main body and radially engaging the at least one supporting member; the raceway of the at least one elastic blade defined by at least a portion of a surface of the blade insert.
2. The torsional vibration damper as defined in claim 1, wherein the main body is made of a first material and the blade insert is made of a different second material.
3. The torsional vibration damper as defined in claim 2, wherein the first material of the main body and the second material of the blade insert of the at least one elastic blade have different mechanical properties.
4. The torsional vibration damper as defined in claim 2, wherein the first material of the main body has greater resiliency than the second material of the blade insert, and wherein the second material of the blade insert has higher hardness than the first material of the main body.
5. The torsional vibration damper as defined in claim 1, wherein the at least one supporting member includes at least one support pin extending axially from the first retainer plate and at least one annular rolling body coaxially mounted on the at least one support pin for rotation around a central axis thereof.
6. The torsional vibration damper as defined in claim 1, wherein the torque input member further includes a radially oriented second side plate, which is axially spaced from and non-moveably attached to the first side plate.
7. The torsional vibration damper as defined in claim 1, wherein the first side plate of the torque input member of the torsional vibration damper has at least one viewing window therethrough configured to expose a portion of the radially elastic output member of the torsional vibration damper therethrough and to identify angular orientation of the elastic blades of the radially elastic output member around the rotational axis.
8. The torsional vibration damper as defined in claim 1, wherein the raceway of the blade insert is coplanar with a radially outer surface of the main body adjacent to the raceway of the at least one elastic blade.
9. The torsional vibration damper as defined in claim 1, wherein the raceway of the blade insert is radially outwardly spaced from a radially outer surface of the main body adjacent to the raceway of the at least one elastic blade.
10. The torsional vibration damper as defined in claim 1, wherein the radially elastic output member, including the output hub and the at least one elastic blade, is made as a single-piece part.
11. A hydrokinetic torque-coupling device for coupling a driving shaft and a driven shaft together, comprising: a casing rotatable about a rotational axis and having a locking surface; a torque converter including an impeller wheel rotatable about the rotational axis and a turbine wheel disposed in the casing coaxially with the rotational axis, the turbine wheel disposed axially opposite to the impeller wheel and hydro-dynamically rotationally drivable by the impeller wheel; and a locking piston axially moveable along the rotational axis to and from the locking surface of the casing, the locking piston having an engagement surface configured to selectively frictionally engage the locking surface of the casing to position the hydrokinetic torque-coupling device into and out of a lockup mode in which the locking piston is mechanically frictionally locked to the casing so as to be non-rotatable relative to the casing; the locking piston including a torsional vibration damper comprising a torque input member including a radially oriented first side plate and at least one supporting member mounted thereto; and a unitary radially elastic output member pivotable relative to and elastically coupled to the torque input member; the radially elastic output member including an output hub coaxial with the rotational axis and rotatable relative the torque input member, and at least one elastic blade non-movably connected to the output hub and configured to elastically and radially engage the at least one supporting member and to elastically bend in the radial direction upon rotation of the first side plate with respect to the radially elastic output member; the at least one elastic blade defining a raceway configured to bear the at least one supporting member; the at least one elastic blade including a main body and a blade insert non-moveably secured to the main body of the at least one elastic blade and radially engaging the at least one supporting member; the raceway of the at least one elastic blade defined by at least a portion of a surface of the blade insert.
12. The hydrokinetic torque-coupling device as defined in claim 11, wherein the main body is made of a first material and the blade insert is made of a different second material.
13. The hydrokinetic torque-coupling device as defined in claim 12, wherein the first material of the main body and the second material of the blade insert of the at least one elastic blade have different mechanical properties.
14. The hydrokinetic torque-coupling device as defined in claim 12, wherein the first material of the main body has greater resiliency than the second material of the blade insert, and wherein the second material of the blade insert has higher hardness than the first material of the main body.
15. The hydrokinetic torque-coupling device as defined in claim 11, wherein the raceway of the blade insert is coplanar with a radially outer surface of the main body adjacent to the raceway of the at least one elastic blade.
16. The hydrokinetic torque-coupling device as defined in claim 11, wherein the raceway of the blade insert is radially outwardly spaced from a radially outer surface of the main body adjacent to the raceway of the at least one elastic blade.
17. The hydrokinetic torque-coupling device as defined in claim 11, wherein the first side plate of the torque input member of the torsional vibration damper non-rotatably engages the turbine wheel.
18. The hydrokinetic torque-coupling device as defined in claim 11, wherein the torque input member is axially moveable relative to both the impeller wheel and turbine wheel to and from the locking surface of the casing.
19. The hydrokinetic torque-coupling device as defined in claim 11, wherein the locking piston further includes a piston member having the engagement surface, and wherein the piston member is non-moveably connected to the torque input member of the torsional vibration damper.
20. The hydrokinetic torque-coupling device as defined in claim 19, wherein the torque input member further includes a radially oriented second side plate, which is axially spaced from and non-moveably attached to the first side plate, and wherein the piston member is non-moveably connected to the second side plate of the torque input member of the torsional vibration damper.
21. The hydrokinetic torque-coupling device as defined in claim 11, wherein the torque input member further includes a radially oriented second side plate, which is axially spaced from and non-moveably attached to the first side plate.
22. The hydrokinetic torque-coupling device as defined in claim 11, wherein the radially elastic output member, including the output hub and the at least one elastic blade, is made as a single-piece part.
23. A radially elastic output member for a torsional vibration damper, the radially elastic output member being rotatable about a rotational axis and comprising: an output hub rotatable relative to the rotational axis; and two elastic blades extending from the output hub; each of the elastic blades being non-movably connected to the output hub; each of the elastic blades including a main body and a blade insert non-moveably secured to the main body; at least a portion of a surface of each blade insert defining a raceway.
24. The radially elastic output member as defined in claim 23, wherein the main body of each of the elastic blades is made of a first material and the blade insert is made of a different second material.
25. The radially elastic output member as defined in claim 23, wherein the output hub includes radially inner splines for operably interconnecting the radially elastic output member with the torsional vibration damper.
26. The radially elastic output member as defined in claim 24, wherein the first material is selected from the group consisting of spring steel, carbon fiber, and composite polymer materials.
27. The radially elastic output member as defined in claim 24, wherein the second material is made of hardened steel having hardness of between HRC 45 to HRC 65.
28. The radially elastic output member as defined in claim 23, wherein the radially elastic output member, including the output hub and the at least one elastic blade, is made as a single-piece part.
29. A method for assembling a torsional vibration damper, the method comprising the steps of: providing a radially oriented first side plate and at least one supporting member; rotatably mounting the at least one supporting member to the first side plate; providing a unitary radially elastic output member, the radially elastic output member including an output hub coaxial with the rotational axis and rotatable relative the torque input member, and at least one elastic blade non-movably connected to the output hub and configured to elastically and radially engage the at least one supporting member and to elastically bend in the radial direction upon rotation of the first side plate with respect to the radially elastic output member; and elastically coupling the elastic output member to the torque input member so that the at least one elastic blade elastically and radially engages the at least one supporting member; the at least one elastic blade defining a raceway configured to bear the at least one supporting member; the at least one elastic blade including a main body and a blade insert non-moveably secured to the main body and radially engaging the at least one supporting member.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0013] The accompanying drawings are incorporated in and constitute a part of the specification. The drawings, together with the general description given above and the detailed description of the exemplary embodiments and methods given below, serve to explain the principles of the invention. The objects and advantages of the invention will become apparent from a study of the following specification when viewed in light of the accompanying drawings, in which like elements are given the same or analogous reference numerals and wherein:
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DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S) AND EMBODIED METHOD(S) OF THE INVENTION
[0029] 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.
[0030] 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.
[0031] A first exemplary embodiment of a hydrokinetic torque-coupling device is generally represented in
[0032] The hydrokinetic torque-coupling device 10 comprises a sealed casing 12 filled with a fluid, such as oil or transmission fluid, and rotatable about a rotational axis X of rotation, a hydrokinetic torque converter 14 disposed in the casing 12, a lock-up clutch 15 and a torque-transmitting device (or torsional vibration damper) 16 also disposed in the casing 12. The torsional vibration damper 16 of the present invention is in the form of a leaf (or blade) damper. The sealed casing 12, the torque converter 14, the lock-up clutch 15 and the torsional vibration damper 16 are 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 device 10 above the rotational axis X. As is known in the art, the torque-coupling device 10 is 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 device 10. 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.
[0033] The sealed casing 12 according to the first exemplary embodiment as illustrated in
[0034] The torque converter 14 comprises an impeller wheel (sometimes referred to as the pump, impeller assembly or impeller) 20, a turbine wheel (sometimes referred to as the turbine assembly or turbine) 22, and a stator (sometimes referred to as the reactor) 24 interposed axially between the impeller wheel 20 and the turbine wheel 22. The impeller wheel 20, the turbine wheel 22, and the stator 24 are coaxially aligned with one another and the rotational axis X. The impeller wheel 20, the turbine wheel 22, and the stator 24 collectively form a torus. The impeller wheel 20 and the turbine wheel 22 may be fluidly coupled to one another in operation as known in the art. In other words, the turbine wheel 22 is hydro-dynamically drivable by the turbine wheel 22.
[0035] The impeller wheel 20 includes a substantially annular, semi-toroidal (or concave) impeller shell 21, a substantially annular impeller core ring 26, and a plurality of impeller blades 25 fixedly (i.e., non-moveably) attached, such as by brazing, to the impeller shell 21 and the impeller core ring 26. Thus, at least a portion of the second shell 17.sub.2 of the casing 12 also forms and serves as the impeller shell 21 of the impeller wheel 20. Accordingly, the impeller shell 21 sometimes is referred to as part of the casing 12. The impeller wheel 20, including the impeller shell 21 (the part of the casing 12), the impeller core ring 26 and the impeller blades 25, are non-rotatably secured to the driving shaft (or flywheel) of the engine to rotate at the same speed as the engine output. The impeller shell 21, impeller core ring 26 and the impeller blades 25 are conventionally formed by stamping from steel blanks.
[0036] The turbine wheel 22, as best shown in
[0037] The impeller shell 21 and the turbine-piston shell 28 collectively define a substantially toroidal first chamber (or torus chamber) 23.sub.1 therebetween. Referring to
[0038] The lock-up clutch 15 includes a locking piston axially moveable along the rotational axis X to and from the locking surface 18 so as to selectively non-rotatably engage the turbine wheel 22 and the casing 12. In turn, the locking piston includes the torsional vibration damper 16 and a substantially annular piston member 34 non-moveably connected (i.e., fixed) to the torsional vibration damper 16. Thus, the torsional vibration damper 16 together with the piston member 34 defines the locking piston of the lock-up clutch 15.
[0039] The piston member 34 has an engagement surface 34e facing the locking surface 18. The piston member 34 is axially moveable along the rotational axis X to and from the locking surface 18 so as to selectively engage the locking surface 18 of the casing 12. The lock-up clutch 15 further includes an annular friction liner 35 fixedly attached to the engagement surface 34e of the piston member 34 by appropriate means known in the art, such as by adhesive bonding. As best shown in
[0040] The annular friction liner 35 is made of a friction material for improved frictional performance. Alternatively, an annular friction liner may be secured to the locking surface 18 of the casing 12. According to still another embodiment, a first friction ring or liner is secured to the locking surface 18 of the casing 12 and a second friction ring or liner is secured to the engagement surface 34e of the piston member 34. It is within the scope of the invention to omit one or both of the friction rings. In other words, the annular friction liner 35 may be secured to any, all, or none of the engagement surfaces. Further according to the exemplary embodiment, the engagement surface 34e of the piston member 34 is slightly conical to improve the engagement with the lock-up clutch 15. Specifically, the engagement surface 34e of the piston member 34 holding the annular friction liner 35 is conical, at an angle of between 10 and 30 relative to the engagement surface 34e of the piston member 34 (or to the plane orthogonal to the rotational axis X), to improve the torque capacity of the lock-up clutch 15. Alternatively, the engagement surface 34e of the piston member 34 may be parallel to the locking surface 18 of the casing 12.
[0041] The torsional vibration damper 16, as best shown in
[0042] The torsional vibration damper 16, as best shown in
[0043] The torsional vibration damper 16 comprises a torque input member 40 rotatable about the rotational axis X, and an integral radially elastic output member 42.sub.1 according to a first exemplary embodiment thereof. The integral radially elastic output member 42.sub.1 is elastically coupled to and configured to pivot (i.e., rotate) relative to the torque input member 40 around the rotational axis X, as best shown in
[0044] The torque input member 40 includes two axially opposite annular, radially oriented retainer plates, including a first annular, radially oriented side plate 46 adjacent to the turbine shell 28, and a second annular, radially oriented side plate 48 adjacent to the piston member 34 and the cover shell 17.sub.1. The first side plate 46 is substantially parallel to and axially spaced from the second side plate 48, as best shown in
[0045] According to the exemplary embodiment of the present invention, as best illustrated in
[0046] Extending axially outwardly at a radially inner peripheral end of the first side plate 46 is a substantially cylindrical, radially inner flange 46if, as best shown in
[0047] Extending axially outwardly at a radially inner peripheral end of the second side plate 48 is a generally cylindrical, radially inner flange 48if, as best shown in
[0048] As further illustrated in
[0049] Moreover, as best shown in
[0050] In addition, the radially oriented first side plate 46 is formed with at least one, and preferably a plurality of second communication openings 55.sub.2 therethrough and circumferentially spaced from each other around the rotational axis X, as best shown in
[0051] Thus, the first and second communication openings 55.sub.1 and 55.sub.2 through the first side plate 46 of the torque input member 40 of the torsional vibration damper 16 and the coupling openings 32 through the turbine shell 28 provide fluid communication between the torus and the damper pressure chambers 23.sub.1 and 23.sub.2, respectively. The first side plate 46 with the coupling arms 47 and the first and second communication openings 55.sub.1 and 55.sub.2 are preferably formed by stamping from a steel blank.
[0052] In an assembled condition of the hydrokinetic torque-coupling device 10, one or more of the coupling arms 47 of the first side plate 46 drivingly engage the turbine shell 28 by axially extending through one or more of the coupling openings 32 in the turbine shell 28 of the turbine wheel 22, as best shown in
[0053] According to the exemplary embodiment of the present invention, the first side plate 46 includes four (4) coupling arms with four (4) first communication openings 55.sub.1, and four (4) second communication openings 55.sub.2, while the turbine shell 28 of the turbine wheel 22 has eight (8) coupling openings 32. In other words, not each of the coupling openings 32 through the turbine shell 28 of the turbine wheel 22 receives one of the coupling arms 47 therethrough. The coupling openings 32 not engaged by the coupling arms 47 and the second communication openings 55.sub.2 provide free hydraulic fluid flow through the first side plate 46 into a cavity axially between the first and second side plates 46 and 48 of the torsional vibration damper 16. Smaller amounts of the hydraulic fluid flow through the rest of the coupling openings 32 and the first communication openings 55.sub.1.
[0054] The torque input member 40 further includes at least one, and preferably two supporting members 50. In the exemplary embodiment, the supporting members 50 are in the form of annular rolling bodies (or cam followers), such as cylindrical rollers rotatably mounted to the radially external peripheries of the first retainer plate 46 and the second side plates 48, and axially disposed between the first and second side plates 46 and 48, respectively. Each of the rolling bodies 50 is rotatable around a central axis C thereof best shown in
[0055] The rolling bodies 50 are positioned so as to be diametrically opposite one another, as best shown in
[0056] The radially elastic output member 42.sub.1, includes an annular output hub 44 coaxial with the rotational axis X and rotatable relative to the torque input member 40, and at least one and preferably two substantially identical, radially opposite curved elastic leaves (or blades) 56.sub.1 integral (or unitary) with (i.e., made as a single part or as a part made of separate components fixedly (i.e., non-moveably) connected together) the output hub 44, as best shown in
[0057] As best shown in
[0058] Each of the curved elastic leaves 56.sub.1 and each of the raceway portions 64 are elastically deformable in radial direction. The bent portion 62 subtends an angle of approximately 180. At least a portion of a radially external surface of the curved raceway portion 64 of each of the curved elastic leaves 56.sub.1 defines a radially outer raceway 66 configured as a surface that is in rolling contact with one of the rollers 50, so that each of the rolling bodies 50 is positioned radially outside of the elastic leaf 56.sub.1, as illustrated in
[0059] As described above, the radially elastic output member 42.sub.1 is configured to be elastically and radially supported by the rolling bodies 50, and to elastically bend in the radial direction upon rotation of the torque input member 40 with respect to the radially elastic output member 42.sub.1, as best shown in
[0060] As best shown in
[0061] The main body 57.sub.1 of each of the curved elastic blades 56.sub.1 is made of highly resilient (i.e., elastic) material, such as spring steel, carbon fiber or composite polymer material. The blade insert 59.sub.1 of each of the curved elastic blades 56.sub.1, on the other hand, is made of hardened steel, such as tool steel (HRC 45-65), and includes the curved raceway portion 64 defining the cam profile. The term tool steel commonly refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools, such as cutting tools. Their suitability comes from their distinctive hardness, resistance to abrasion and deformation and their ability to hold a cutting edge at elevated temperatures. As a result, tool steels are suited for their use in the shaping of other materials. Thus, the main body 57.sub.1 and the blade insert 59.sub.1 of the at least one elastic blades 56.sub.1 are made of materials having different chemical composition and mechanical properties. Specifically, the main body 57.sub.1 is made of a first material, and the blade insert 59.sub.1 is made of a second material, which is different from the first material. In other words, the first and second materials have different chemical composition and mechanical properties. Moreover, the first material of the main body 57.sub.1 has greater elasticity (resiliency) than the second material of the blade insert 59.sub.1, while the second material of the blade insert 59.sub.1 has higher hardness than the first material of the main body 57.sub.1.
[0062] The radially outer raceway 66 of each of the curved elastic blades 56.sub.1 is defined by at least a portion of a radially outer surface of the blade insert 59.sub.1 (made of hardened steel) that is in rolling contact with an associated one of the rollers 50. Preferably, the radially outer raceway 66 of each of the curved elastic blades 56.sub.1 is defined only by the radially outer surface of the blade insert 59.sub.1 that is in rolling contact with the associated one of the rollers 50. Thus, the rollers 50 travel on the blade insert 59.sub.1 and do not make contact with the main body 57.sub.1 of the curved elastic blade 56.sub.1. As best shown in
[0063] At least one of the first and second side plates 46 and 48 of the torsional vibration damper 16 is formed with at least one, and preferably a plurality of viewing windows 49 therethrough, as best shown in
[0064] In operation, when a rolling body 50 moves along the raceway 66 of the blade insert 59.sub.1 of the curved elastic leaf 56.sub.1, the rolling body 50 presses the curved raceway portion 64 of the curved elastic leaf 56.sub.1 radially inwardly, thus maintaining contact of the rolling body 50 with the curved raceway portion 64 of the curved elastic leaf 56.sub.1, as best illustrated in
[0065] In the disengaged position of the lock-up clutch 15, the torque flows through the torque converter 14, i.e. the impeller wheel 20 and then the turbine wheel 22 non-rotatably coupled to the to the first side plate 46 of the torque input member 40. The torque is then transmitted to the driven shaft (transmission input shaft) 2 splined directly to the output hub 44. In the engaged position of the lock-up clutch 15, torque from the casing 12 is transmitted to the torque input member 40 (i.e., the first and the second side plates 46 and 48, and the rolling bodies 50) through the elastic output member 42 formed by the output hub 44 and the elastic leaves 56. The torque is then transmitted from the output hub 44 of the elastic output member 42 to the driven shaft (transmission input shaft) 2 splined to the output hub 44. Moreover, when the torque transmitted between the casing 12 and the output hub 44 of the elastic output member 42 varies, the radial forces exerted between each of the elastic leaves 56 and the corresponding rolling bodies 50 vary and bending of the elastic leaves 56 is accordingly modified. The modification in the bending of the elastic leaf 56 comes with motion of the rolling body 50 along the associated raceway 66 of the curved elastic leaf 56 due to stresses.
[0066] The raceway 66 has a profile so arranged that, when the transmitted torque increases, the rolling body 50 exerts a bending force on the corresponding curved elastic leaf 56.sub.1 which causes the free distal end 60 of the curved elastic leaf 56.sub.1 to move radially towards the rotational axis X and produces a relative rotation between the torque input member 40 and the output hub 44 of the elastic output member 42, such that both the first and the second side plates 46, 48 and the output hub 44 move away from their relative rest positions. A rest position is that position of the torque input member 40 relative to the elastic output member 42, wherein no torque is transmitted between the casing 12 and the output hub 44 of the elastic output member 42 through the rolling bodies 50.
[0067] The profiles of the raceways 66 are such that the rolling bodies 50 exert bending forces (pressure) having radial and circumferential components onto the curved elastic leaves 56. Specifically, the elastic leaves 56 are configured so that in a relative angular position between the torque input member 40 and the elastic output member 42 different from the rest position, each of the rolling bodies 50 exerts a bending force on the corresponding elastic leaf 56, thus causing a reaction force of the elastic leaf 56 acting on the rolling body 50, with the reaction force having a radial component which tends to maintain the elastic leaf 56 in contact with the rolling body 50. In turn, each of the elastic leaves 56 exerts onto the corresponding rolling body 50 a back-moving force having a circumferential component which tends to rotate the rolling bodies 50 in a reverse direction of rotation, and thus to move the torque input member 40 (thus, the turbine wheel 22) and the output hub 44 of the elastic output member 42 back towards their relative rest positions, and a radial component directed radially outwardly, which tends to maintain each of the raceways 66 in direct contact with the corresponding rolling body 50. When the torque input member 40 and the elastic output member 42 are in the rest position, the elastic leaves 56 are preferably radially pre-stressed toward the rotational axis X so as to exert a reaction force directed radially outwards, to thus maintain the curved elastic leaves 56 in engagement with the associated rolling bodies 50.
[0068] Moreover, the profiles of the raceways 66 are so arranged that a characteristic transmission curve of the torque according to the angular displacement of the rolling body 50 relative to the raceway 66 is symmetrical or asymmetrical relative to the rest position as may be desired. According to the exemplary embodiment, the angular displacement of the rolling body 50 relative to the raceway 66 is more important in a direct direction of rotation than in a reverse (i.e., opposite to the direct) direction of rotation.
[0069] According to the exemplary embodiment, the angular displacement of the casing 12 relative to the elastic output member 42.sub.1 in the locked position of the lock-up clutch 15 is greater than 20, preferably greater than 40. The curved elastic leaves 56.sub.1 are regularly distributed around the rotational axis X and are symmetrical relative to the rotational axis X so as to ensure the balance of the torque converter 14.
[0070] Various modifications, changes, and alterations may be practiced with the above-described embodiment of the elastic output member 42.sub.1, including but not limited to the additional embodiments shown in
[0071] Alternatively, the torsional vibration damper 16 of the hydrokinetic torque-coupling device 10 may comprise an integral radially elastic output member 42.sub.2 according to a second exemplary embodiment thereof illustrated in
[0072] The radially elastic output member 42.sub.2 includes an annular output hub 44 coaxial with the rotational axis X and rotatable relative the torque input member 40, and at least one and preferably two substantially identical, radially opposite curved elastic leaves (or blades) 56.sub.2 integral (i.e., unitary) with the output hub 44, as best shown in
[0073] As best shown in
[0074] Each of the curved elastic leaves 56.sub.2 and each of the raceway portions 64 are elastically deformable. The bent portion 62 subtends an angle of approximately 180. A portion of a radially external surface of the curved raceway portion 64 of each of the curved elastic leaves 56.sub.2 defines a radially outer raceway 66 configured as a surface that is in a rolling contact with one of the rollers 50, so that each of the rolling bodies 50 is positioned radially outside of the elastic leaf 56.sub.2, as illustrated in
[0075] As best shown in
[0076] The main body 57.sub.2 of each of the curved elastic blades 56.sub.2 is made of flexible (i.e., elastic) material, such as spring steel, carbon fiber or composite polymer material. The blade insert 59.sub.2 of each of the curved elastic blades 56.sub.2, on the other hand, is made of hardened steel, such as tool steel (HRC 45-65), and includes the curved raceway portion 64 defining the cam profile.
[0077] The radially outer raceway 66 of each of the curved elastic blades 56.sub.2 is defined by at least a portion of a radially outer surface of the blade insert 59.sub.2 (made of hardened steel) that is in rolling contact with one of the rollers 50. Thus, the rollers 50 each travel on the blade insert 59.sub.2 and do not make contact with the main body 57.sub.2 of the associated curved elastic blade 56.sub.2.
[0078] As best shown in
[0079] In operation, when a rolling body 50 moves along the raceway 66 of the blade insert 59.sub.2 of the curved elastic leaf 56.sub.2, the rolling body 50 presses the curved raceway portion 64 of the curved elastic leaf 56.sub.2 radially inwardly, thus maintaining contact of the rolling body 50 with the curved raceway portion 64 of the curved elastic leaf 56.sub.2.
[0080] Further alternatively, the torsional vibration damper 16 of the hydrokinetic torque-coupling device 10 may comprise an integral radially elastic output member 42.sub.3 according to a third exemplary embodiment thereof illustrated in
[0081] The radially elastic output member 42.sub.3 includes an annular output hub 44 coaxial with the rotational axis X and rotatable relative the torque input member 40, and at least one and preferably two substantially identical, radially opposite curved elastic leaves (or blades) 56.sub.3 integral (i.e., unitary) with the output hub 44, as best shown in
[0082] As best shown in
[0083] Each of the curved elastic leaves 56.sub.3 and each of the raceway portions 64 are elastically deformable. The bent portion 62 subtends an angle of approximately 180. A portion of a radially external surface of the curved raceway portion 64 of each of the curved elastic leaves 56.sub.3 defines a radially outer raceway 66 configured as a surface that is in a rolling contact with one of the rollers 50, so that each of the rolling bodies 50 is positioned radially outside of the elastic leaf 56.sub.3, as illustrated in
[0084] As best shown in
[0085] The main body 57.sub.3 of each of the curved elastic blades 56.sub.3 is made of flexible (i.e., elastic) material, such as spring steel, carbon fiber or composite polymer material. The blade insert 59.sub.3 of each of the curved elastic blades 56.sub.3, on the other hand, is made of hardened steel, such as tool steel (HRC 45-65), and includes the curved raceway portion 64 defining the cam profile.
[0086] The radially outer raceway 66 of each of the curved elastic blades 56.sub.3 is defined by at least a portion of a radially outer surface of the blade insert 59.sub.3 (made of hardened steel) that is in rolling contact with one of the rollers 50. Thus, the rollers 50 travel on the blade insert 59.sub.3 and do not make contact with the main body 57.sub.3 of the curved elastic blade 56.sub.3.
[0087] As best shown in
[0088] In operation, when a rolling body 50 moves along the raceway 66 of the blade insert 59.sub.3 of the curved elastic leaf 56.sub.3, the rolling body 50 presses the curved raceway portion 64 of the curved elastic leaf 56.sub.3 radially inwardly, thus maintaining contact of the rolling body 50 with the curved raceway portion 64 of the curved elastic leaf 56.sub.3.
[0089] Further alternatively, the torsional vibration damper 16 of the hydrokinetic torque-coupling device 10 may comprise an integral radially elastic output member 42.sub.4 according to a fourth exemplary embodiment thereof illustrated in
[0090] The radially elastic output member 42.sub.4 includes an annular output hub 44 coaxial with the rotational axis X and rotatable relative the torque input member 40, and at least one and preferably two substantially identical, radially opposite curved elastic leaves (or blades) 56.sub.4 integral (i.e., unitary) with the output hub 44, as best shown in
[0091] As best shown in
[0092] Each of the curved elastic blades 56.sub.4 and each of the raceway portions 64 are elastically deformable. The bent portion 62 subtends an angle of approximately 180. A portion of a radially external surface of the curved raceway portion 64 of each of the curved elastic blades 56.sub.4 defines a radially outer raceway 66 configured as a surface that is in a rolling contact with one of the rollers 50, so that each of the rolling bodies 50 is positioned radially outside of the elastic blade 56.sub.4, as illustrated in
[0093] As best shown in
[0094] As best shown in
[0095] The main body 57.sub.4 of each of the curved elastic blades 56.sub.4 is made of flexible (i.e., elastic) material, such as spring steel, carbon fiber or composite polymer material. The blade insert 59.sub.4 of each of the curved elastic blades 56.sub.4, on the other hand, is made of hardened steel, such as tool steel (HRC 45-65), and includes the curved raceway portion 64 defining the cam profile.
[0096] The radially outer raceway 66 of each of the curved elastic blades 56.sub.4 is defined by at least a portion of a radially outer surface of the blade insert 59.sub.4 (made of hardened steel) that is in a rolling contact with one of the rollers 50. Thus, the rollers 50 travel on the blade insert 59.sub.4 and do not make contact with the main body 57.sub.4 of the curved elastic blade 56.sub.4.
[0097] In operation, when a rolling body 50 moves along the raceway 66 of the blade insert 59.sub.4 of the curved elastic leaf 56.sub.4, the rolling body 50 presses the curved raceway portion 64 of the curved elastic leaf 56.sub.4 radially inwardly, thus maintaining contact of the rolling body 50 with the curved raceway portion 64 of the curved elastic leaf 56.sub.4.
[0098] The radially elastic output members 42.sub.1-42.sub.4 and the curved elastic blades 56.sub.1-56.sub.4, are substantially geometrically identical to each other in the exemplary embodiment of the present invention. In view of these similarities, and in the interest of simplicity, the description of the exemplary embodiments and methods of the invention occasionally uses a reference numeral 42 and 56 without a subscript numeral to designate an entire group of substantially geometrically identical radially elastic output members. For example, the reference numeral 42 will be used when generically referring to each of the radially elastic output members 42.sub.1-42.sub.4 rather than reciting all four reference numerals, while the reference numeral 56 will be used when generically referring to each of the radially elastic output members 56.sub.1-56.sub.4.
[0099] The lock-up clutch 15 is provided for locking the driving shaft and the driven shaft 2 together. In other words, the lock-up clutch 15 is configured to non-rotatably couple the casing 12 and the torque input member 40 in the engaged (locked) position, and configured to drivingly disengage the casing 12 and the torque input member 40 in the disengaged (open) position.
[0100] The lock-up clutch 15 is usually activated after starting of the motor vehicle and after hydraulic coupling of the driving and driven shafts, in order to avoid the loss of efficiency caused in particular by slip phenomena between the turbine wheel 22 and the impeller wheel 20. The piston member 34 is axially displaceable toward (an engaged (or locked) position of the lock-up clutch 15) and away (a disengaged (or open) position of the lock-up clutch 15) from the locking surface 18 inside the casing 12. Moreover, the piston member 34 is axially displaceable away from and toward the locking surface 18 of the casing 12 together with the torsional vibration damper 16 relative to the driven shaft 2 along the rotational axis X. The sealing member (e.g., the sealing ring) 72 creates a seal at the interface of the cylindrical flange 48if of the second side plate 48 and the driven shaft 2.
[0101] The axial motion of the piston member 34 and the torsional vibration damper 16 along the driven shaft 2 is controlled by a pressure differential between the torus and damper pressure chambers 23.sub.1 and 23.sub.2 positioned on axially opposite sides of the torsional vibration damper 16.
[0102] The piston member 34 is selectively pressed against the locking surface 18 of the casing 12 so as to lock-up the torque-coupling device 10 between the driving shaft and the driven shaft 2 to control sliding movement between the turbine wheel 22 and the impeller wheel 20. As discussed above, the torque input member 40 of the torsional vibration damper 16 with the piston member 34 is axially movable toward and away from the locking surface 18 of the casing 12 between the lockup position and the non-lockup (open) position. Axial movement of the torque input member 40 is accomplished by changing the pressure differential between the torus and damper pressure chambers 23.sub.1 and 23.sub.2. A pressure increase in the torus chamber 23.sub.1 relative to the damper chamber 23.sub.2 (or stated differently, a pressure decrease in the damper chamber 23.sub.2 relative to the torus chamber 23.sub.1) shifts the torsional vibration damper 16 and the piston member 34 axially in the direction of torque transmission, i.e., towards the locking surface 18 of the casing 12, that is left to right in
[0103] Specifically, when the pressure in the torus chamber 23.sub.1 increases relative to the damper chamber 23.sub.2, the hydraulic fluid from the torus chamber 23.sub.1 flows under pressure into the cavity between the first and second side plates 46 and 48 of the torsional vibration damper 16 through the coupling openings 32 in the turbine shell 28 of the turbine wheel 22 and the first and second communication openings 55.sub.1 and 55.sub.2 in the first side plate 46. As a result, the hydraulic fluid from the torus chamber 23.sub.1 presses the second side plate 48 in the direction away from the turbine wheel 22 so as to displace the torsional vibration damper 16 with the piston member 34 towards the locking surface 18 of the casing 12. In other words, when an appropriate hydraulic pressure in applied to the torque input member 40 of the torsional vibration damper 16, the torsional vibration damper 16 with the piston member 34 moves rightward (as shown in
[0104] On the other hand, a pressure increase in the damper chamber 23.sub.2 relative to the torus chamber 23.sub.1 (or stated differently a pressure decrease in the torus chamber 23.sub.1 relative to the damper chamber 23.sub.2) shifts the torsional vibration damper 16 and the piston 34 affixed thereto axially against the direction of torque transmission, i.e., away from the locking surface 18 of the casing 12, that is right to left in
[0105] During operation, when the lock-up clutch 15 is in the disengaged (open) position, the engine torque is transmitted from the impeller wheel 20 by the turbine wheel 22 of the torque converter 14 to the driven shaft 2 through the torsional vibration damper 16. When the lock-up clutch 15 is in the engaged (locked) position, the engine torque is transmitted by the casing 12 to the driven shaft 2 also through the torsional vibration damper 16.
[0106] A method for assembling the hydrokinetic torque-coupling device 10 is as follows. It should be understood that this exemplary method may be practiced in connection with the other embodiments described herein. This exemplary method is not the exclusive method for assembling the turbine assembly described herein. While the methods for assembling the hydrokinetic torque-coupling device 10 may be practiced by sequentially performing the steps as set forth below, it should be understood that the methods may involve performing the steps in different sequences.
[0107] The method for assembling the hydrokinetic torque-coupling device 10 is as follows. First, the impeller wheel 20, the turbine wheel 22, the stator 24, and the torsional vibration damper 16 may each be preassembled. The impeller wheel 20 and the turbine wheel 22 are formed by stamping from steel blanks or by injection molding of a polymeric material. The turbine shell 28 of the turbine wheel 22 is formed with at least one, preferably a plurality of coupling openings 32 therethrough and circumferentially spaced from each other. The stator 24 is made by casting from aluminum or injection molding of a polymeric material. The impeller wheel 20, the turbine wheel 22 and the stator 24 subassemblies are assembled together so as to form the torque converter 14.
[0108] The torsional vibration damper 16 is then added. The first side plate 46 with the coupling arms 47 and the first and second communication openings 55.sub.1 and 55.sub.2 is formed by stamping from a steel blank. The second side plate 48 is also formed by stamping from a steel blank. Before the torsional vibration damper 16 is assembled, the piston member 34 of the lock-up clutch 15 is fixed (i.e., non-movably secured) to the first side plate 46 of the torque input member 40 by appropriate means, such as by welding, adhesive bonding or fasteners, such as rivets. Next, the torsional vibration damper 16 is mounted to the turbine wheel 22 so that the turbine shell 28 non-rotatably engages the first side plate 46 of the torque input member 40 of the torsional vibration damper 16. Specifically, the coupling arms 47 of the first side plate 46 engage the coupling openings 32 of the turbine shell 28.
[0109] The elastic output member 42 is formed with the output hub 44 and at least one and preferably two substantially identical, radially opposite curved elastic blades 56 as an integral (or unitary) component, e.g., made as a single part, but may be made of separate components fixedly connected together. The elastic output member 42 includes a main body 57 and a blade insert 59 non-moveably secured (i.e., fixed) to the main body 57 of each of the curved elastic leaves 56. The blade insert 59 is fixed to the main body 57 of each of the curved elastic leaves 56 by appropriate means, such as mechanical fasteners (e.g., rivets or screws), welding (such as laser welding), adhesive bonding, etc. The main body 57 of each of the curved elastic blades 56 is made of flexible material, such as spring steel, carbon fiber or composite polymer material. The blade insert 59 of each of the curved elastic blades 56, on the other hand, is made of hardened steel, such as tool steel (HRC 45-65). The term tool steel commonly refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools. Their suitability comes from their distinctive hardness, resistance to abrasion and deformation and their ability to hold a cutting edge at elevated temperatures. As a result, tool steels are suited for their use in the shaping of other materials.
[0110] Then, the first shell 17.sub.1 is non-moveably and sealingly secured, such as by welding at 19, to the second shell 17.sub.2, as best shown in
[0111] Therefore, the torsional vibration damper of the hydrokinetic torque-coupling device of the present invention provides a number of advantages over the conventional torsional vibration damper. Specifically, the torsional vibration damper of the hydrokinetic torque-coupling device of the present invention simplifies the design, makes assembly of the hydrokinetic torque-coupling device easier, and saves both weight and manufacturing cost of the hydrokinetic torque-coupling device. Moreover, the radially elastic output member of the present invention improves performance, mechanical characteristics and durability of the torsional vibration damper.
[0112] The foregoing description of the exemplary embodiments 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.