192 clutches and power-stop control – Vortex-flow drive and clutch – Including drive-lockup clutch
Reexamination Certificate
1999-09-23
2001-02-27
Lorence, Richard M. (Department: 3681)
192 clutches and power-stop control
Vortex-flow drive and clutch
Including drive-lockup clutch
C192S070180
Reexamination Certificate
active
06193036
ABSTRACT:
The present invention concerns hydrokinetic coupling appliances, notably for motor vehicles, equipped with a locking clutch, usually referred to as a “lock-up” clutch, for mechanically making their turbine wheel and their impeller wheel integral with respect to rotation, as described for example in the document FR-A-2 726 620.
In this document, the hydrokinetic coupling appliance has, inside a sealed casing, filled with oil, a torque converter with a turbine wheel and an impeller wheel, and a lock-up clutch.
In general terms the casing has a first half-shell provided with an axially fixed transverse wall by means of which it is connected to the driving shaft. The turbine wheel is connected to an internally fluted hub for rotatably connecting it to a driven shaft.
The first half-shell, and therefore the casing, forms the input element of the hydrokinetic coupling appliance which is rotary in operation, whilst the hub forms the output element of the said appliance.
Being a case of an application for a motor vehicle, the driving shaft consists of the crankshaft of the vehicle engine, whilst the driven shaft consists of the input shaft of the transmission box.
The lock-up clutch has at least one friction lining which, fixed with respect to rotation to the turbine wheel and hub, either directly, or indirectly by means of a torsion damper, is disposed axially between on the one hand the said transverse wall fixed with respect to the impeller wheel and on the other hand a piston which is mounted so as to be able to move axially with respect to the transverse wall forming a counter-piston. This piston is rotatably connected to the transverse wall, usually by elastic tongues substantially elongated tangentially to a circumference of the whole. This type of circumferentially acting tongue will hereinafter be referred to as a tangential tongue.
These tongues are mounted inside a variable-volume control chamber delimited on the one hand radially externally by the friction lining and radially internally by a cylindrically shaped centring device adjacent to the transverse wall and on the other hand axially by the piston and transverse wall.
These tongues are fixed at one of their ends firstly in a fluidtight manner to the transverse wall of the casing, either directly or by means of a driving piece which is separate or in a single piece with the tangential tongue.
This fixing is easy to achieve, for example by means of rivets issuing by extrusion from the transverse wall.
Next the other end of the tongue is fixed to the piston. Having regard to the location of the tongues in the control chamber, this fixing is effected by means of two-part fixing members, for example a rod with a shouldered head mounted in the control chamber.
This rod passes, with radial clearance, through the piston and is connected by crimping to a ring situated outside the control chamber.
The rod is fixed to the tongues. Thus the fixing is effected by acting on only one side of the outside of the control chamber and by breaking the rod.
The fixing members are therefore relatively expensive and it is necessary to have recourse to a traction tool for breaking the rod and a crimping tool for crimping the ring on the notched rod.
The object of the present invention is to mitigate this drawback, in a simple and economical fashion.
An aim of the invention is therefore to fix the elastic tongues to the elastic fixing member of standard type, whilst locating the tongues in the control chamber.
According to the invention, a lock-up clutch of the type indicated above in which the elastic tongues are fixed on the one hand at one of their circumferential ends by first means of fixing to one of the transverse wall/piston pieces, referred to as the first piece, and on the other hand at the other one of their circumferential ends by second means of fixing to the other one of the transverse wall/piston pieces, referred to as the second piece, is characterised in that the first piece has passage holes coinciding axially with the second fixing means and in that the passage holes are closed off at the end by sealing obturators.
By virtue of the invention the fixing means can be of the same type. Because it is possible to act, by virtue of the invention, on both sides of the transverse wall/piston pieces, the tongues can be fixed by bonding or welding to the pieces in question. The fixing means, in a variant, can consist of fixing members.
By virtue of the invention the fixing members are then more economical and can be of a standard type without there being any need to break a rod and to crimp a ring because, by virtue of the passage holes, it is possible to act on both sides of the second piece on the second fixing members by means, in a known fashion, of a tool and a counter-tool.
Thus the piston can be fixed to the tongues by means of simple rivets passing through associated openings in the piston with smaller radial clearance so that coupling of the piston to the elastic tongues is more certain.
The relative movements between the piston and the tongues are reduced in all cases.
The first fixing members can be identical to the second fixing members. For example, it can be a case of conventional rivets or rivets formed by extrusion from the transverse wall and the piston.
The obturators are introduced at the end, after fixing of the tongues, in the passage holes in order to close these off in a fluidtight manner.
The obturators can, for this purpose, be force-fitted, or fitted by contraction followed by expansion in the passage holes, or fixed by welding, snapping-in, screwing, deformation, crimping or bonding to the transverse wall/piston piece concerned.
Naturally, depending on whether the holes are produced in the transverse wall or the piston, it is possible to first of all fix the tongues to the transverse wall and then to the piston or in the other case first of all fix the tongues to the piston and then to the transverse wall. Naturally, passage holes can be provided in the piston and in the transverse wall.
By virtue of the invention there are therefore more possibilities, with regard to the manufacturing process, whilst having the possibility of acting axially in both directions, that is to say on each side of the piston and of the transverse wall and without using a tool for crimping a ring and breaking a rod by traction.
In one embodiment, the obturators consist of plugs.
Advantageously, the passage holes are stepped in diameter in order to form a transverse internal shoulder connecting the smaller-diameter portion to the larger-diameter portion of the passage hole.
Advantageously, the plug is also stepped in diameter whilst being shouldered, in a manner complementary to that of the passage hole. As a result the plug has a head and a body and the larger-diameter head of the plug comes to be housed in the larger-diameter portion of the passage hole and comes into abutment against the shoulder of this hole by means of its transverse shoulder connecting the head of the plug to its smaller-diameter body introduced into the smaller-diameter portion of the passage hole.
This body can be knurled for forcible introduction of the plug into the passage hole.
This body can be threaded and the smaller-diameter portion of the passage hole is then given a female thread. The plug is then screwed into one of the transverse wall/piston pieces. The plug is shorter axially than the passage hole.
It will be appreciated, when the plug with a shouldered head is introduced into the stepped passage hole of the piston, that the hydraulic pressure prevailing on the side of the piston opposite to the control chamber prevents the plug from coming out again when the lock-up clutch is engaged since the said pressure is then greater than that prevailing in the control chamber.
All this harmonises well with the dished shape of the piston increasing its strength. Naturally the elastic tongues can be inclined. In all cases they are circumferentially oriented and axially elastic.
As a variant, the obturator consists of a ring. The passage holes are then step
Arhab Rabah
Bochot Jean-Claude
Lemaire Alain
Thevenon Luc
Liniak Berenato Longacre & White
Lorence Richard M.
Valeo
LandOfFree
Hydrokinetic coupling apparatus with lock-up clutch for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydrokinetic coupling apparatus with lock-up clutch for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydrokinetic coupling apparatus with lock-up clutch for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2593166