192 clutches and power-stop control – Vortex-flow drive and clutch – Including drive-lockup clutch
Reexamination Certificate
1999-05-05
2001-06-12
Lorence, Richard M. (Department: 3681)
192 clutches and power-stop control
Vortex-flow drive and clutch
Including drive-lockup clutch
C192S070170, C192S213100, C464S066100
Reexamination Certificate
active
06244401
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a torque-transmitting apparatus with a fluid-operated torque coupler such as, e.g., a fluid coupling or a hydrodynamic torque converter, with at least one housing that can be connected to a driving shaft of a prime mover. The housing contains at least one impeller pump receiving torque from the housing and a turbine that is connected to the input shaft, such as a transmission shaft, of a power train to be driven. Also, if applicable, the housing contains at least one stator arranged between the pump and the turbine. Further, at least one damper is arranged in the power flow between the turbine and a rotary output element of the device. The damper has an input member constrained to rotate together with the turbine and an output member connected to the rotary output element. The input member and the output member are rotatable relative to each other at least against the opposition of a restoring force furnished by energy-storing devices arranged between them.
Torque-transmitting apparatuses of this kind have been proposed, e.g., in DE-OS 195 14 411. To allow rotational displacement of the input and output members relative to each other, it is customary for torque-transmitting apparatuses of this kind to be equipped with a hub that has a toothed internal profile establishing a positive engagement with the transmission shaft and also a toothed external profile which mates with a further component, normally a further hub that carries the turbine and has a toothed internal profile, with play between the flanks of the mating teeth. When a lockup clutch is added that is activated by an axial control piston, there needs to be a corresponding axial space to allow for the axial travel of the hub containing the two toothed profiles. The manufacture of hubs of this kind is complex and therefore expensive. Furthermore, due to the required axial dimension, longer transmission shafts will be needed. Added to this is the difficulty of connecting bulky hub components with the filigreed construction of the turbine shell. Also, dampers that extend far in the radial direction have a tendency to wobble. If in an attempt to solve these problems, the damper is axially docked to the turbine along two or more perimeters of different radii, this will cause undesirable stresses and frictional losses in the damper.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to improve the design of a torque-transmitting apparatus in a manner that allows a stress-free accommodation of the damper as well as economical and technical improvements in the manufacturing process for torque-transmitting apparatuses of this kind. According to a further object of the invention, the device is to be manufacturable in such a manner that a modular assembly without time-consuming fastening operations can be performed during final assembly. Also required of the torque-transmitting apparatus are the capabilities to transfer torque of high magnitude and to attenuate rotational perturbations over a broad RPM range. Besides, the unit is to meet the objectives that it will minimize wear and prolong the useful life of the overall system of which it is a part.
SUMMARY OF THE INVENTION
The invention is embodied in a torque-transmitting apparatus of the kind that has a fluid-operated torque coupler such as a hydrodynamic torque converter or a similar device comprising
at least one housing that can be connected to a driving shaft of a prime mover,
at least one pump that is arranged inside of and driven by the housing,
a turbine that is connected to and drives the input shaft of a power train such as a transmission shaft and also, if applicable,
at least one stator arranged between the pump and the turbine, and further
at least one damper arranged in the torque-flow path between the turbine and a rotary output element of the apparatus, with an input member of the damper being constrained to rotate together with the turbine and an output member of the damper being connected to the rotary output element, the input member and the output member being at least rotatable relative to each other at least against the opposition of the restoring force exerted by energy-storing devices arranged between them.
In accordance with one presently preferred embodiment of the improved torque-transmitting apparatus, the damper at its outside perimeter is directly or indirectly connected to the turbine through a positive rotational constraint. This connection may be free of play relative to coaxial rotational displacements but may allow an axial displacement of the turbine and the input member of the damper relative to each other. For example, the connection may be axially displaceable by means of an axial plug-in connection with the damper rigidly attached to a hub. The problem can further be solved through a torque-transmitting apparatus with a damper whose connection to the turbine shell or turbine, or to the hub, is rotationally fixed both along an inside and outside perimeter, while in the axial direction the connection is fixed only along one perimeter, either on the hub or on the turbine shell, so that axial stresses are relieved by an axial displacement at the axially nonrestrained connection.
In accordance with a further inventive concept, there may also be an axially and rotationally fixed connection at the outside perimeter of the damper in which case, in order to prevent stresses in the damper, the inside perimeter of the damper may be designed to be axially displaceable, e.g., in an arrangement where the damper, by means of a positive circumferential coupling such as a toothed profile, engages a complementary profile on the hub. In addition, the profile on the hub may be axially fixed but rotatable on a complementary profile of the turbine hub on which the turbine is seated, with the amount of rotational play designed to be at least equal to the working range, i.e., the effective angular range, of the damper. The play in the form-fitting engagement between the turbine hub and the hub may also be obtained through additional devices such as window-like openings that are distributed over the circumference of the hub and are engaged with angular play by a corresponding series of axially directed projections on the turbine hub.
With particular advantage, the connection between the turbine and the input member of the damper is accomplished through welding processes such as laser welding, impulse welding, or resistance welding, in which case the damper can be centered on the hub by means of a disk-shaped part that holds the energy-storing devices, or on the turbine shell, e.g., by providing the turbine shell with a series of projections that are distributed over the circumference and that may also serve as locating references for the weld.
It is advantageous for the torque-transmitting apparatus to be provided with a lockup clutch arranged in the torque-flow path between the driving shaft and the damper, in which case it has proved to be beneficial if the lockup clutch, by means of friction linings or laminar disks, establishes a positive engagement with a housing surface and transfers the torque to be transmitted directly to the input member of the damper. Thus, when the lockup clutch is engaged, the torque converter is bypassed and the torque to be transmitted is introduced directly into the damper and from there to the rotary output element and subsequently to the transmission shaft. When the lockup clutch is disengaged, the turbine will impart the torque that has been converted—in most cases amplified through the effect of the stator—to the input member of the damper from where the torque will follow the same path as has been previously described.
The clutch can be engaged and disengaged through an axially moveable control piston that is controlled by an application of pressure. It is advantageous if the control piston defines a plenum chamber which, in the engaged state of the lockup clutch, is essentially sealed tight against the interior space of the housing (except for i
Honemann Rudolf
Maienschein Stephan
Meisner Marc
Darby & Darby
Lorence Richard M.
LuK Getriebe-Systeme GmbH
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