192 clutches and power-stop control – Clutches – Torque responsive
Reexamination Certificate
2000-03-02
2001-10-16
Lorence, Richard M. (Department: 3681)
192 clutches and power-stop control
Clutches
Torque responsive
C192S070170, C074S00700R, C290S046000, C310S074000
Reexamination Certificate
active
06302253
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a torque transmission unit having a torsion damping device and a shift clutch arranged between an input shaft and an output shaft and an electric machine with a rotor concentrically arranged relative to a stator, the rotor being effectively connected with the input shaft.
2. Description of the Related Art
A torque transmission unit is disclosed in German references DE 43 23 601 A1 and DE 43 23 602 A1 having an electric machine combined with a torsion damping device and a shift clutch. These references show that one of the shift clutch and the torsion damping device may be arranged within a central construction space delimited by the stator of the electric machine. Torsion damping elements of the torsion damping devices are shown as being integrated into the clutch disk of the shift clutch. While the known means for torsion damping do reduce torsional vibrations, these known means are not sufficient particularly, for example, in luxury vehicles in which special vibration damping is expected and in compact economy vehicles which are designed for a particularly low energy consumption and therefore typically have a more pronounced vibration behavior within the drive train. Although it is possible to employ an electric machine for additional torsion damping, the use of the electric machine for this purpose consumes additional energy.
SUMMARY OF THE INVENTION
The object of the invention is to provide a torque transmission unit for a motor vehicle having good torsion damping characteristics while optimizing the consumption of the electric energy used for torsion damping and simultaneously uses only a small construction space.
The object is achieved by a torque transmission unit according to an embodiment of the present invention having a torsion damping device comprising a primary flywheel mass rotatable relative to a second flywheel mass, the primary mass being effectively connected to an input shaft of the torque transmission unit and the secondary flywheel mass being effectively connected to the output shaft. The torque transmission unit further comprises a shift clutch and an electric motor having a stator and a rotor, wherein the rotor is effectively connected to the input shaft. Furthermore, at least one of the torsion damping device and the shift clutch are arranged within an annular space delimited by the rotor and stator of the electric machine.
The use of the primary and secondary flywheel masses markedly improves torsional vibration damping such that the amount of energy used by the electric machine for torsional vibration damping may be reduced. The mass of known torsion damping devices typically comprise a fluid damping device to damp vibrations at low rotational speeds such as when an internal combustion engine is started or stopped. However, optimum torsional vibration damping may be achieved by an electric machine at these low rotational speeds with comparatively low energy consumption because the torques which occur are comparatively low. Therefore, the use of these fluid damping devices may be eliminated to markedly reduce the outlay in terms of construction for the inventive torsion damping device in the torque transmission unit of the present invention.
Furthermore, the above described embodiment of the present invention beneficially utilizes the axial construction space so that even compact economy vehicles may be equipped with the torque transmission unit according to the present invention.
The internal combustion engines used in economy vehicles with optimized consumption and having a small number of cylinders often suffer from noticeably less than true running properties. A larger flywheel mass may be used to improve the running properties of an internal combustion engine within certain limitations. To utilize this principle, the primary mass of the torsion damping device of the present invention is connected to the rotor of the electric machine which enlarges the primary mass. The rotor of the electric machine thus comprises part of a flywheel mass for the internal combustion engine.
Alternatively, the secondary mass of the torsion damping device may be connected to the rotor of the electric machine. This alternative configuration may be used in torsion damping devices having a design in which a starting aid function is achieved for the internal combustion engine by virtue of the work which is stored in the torsion damping device. The work stored in the torsion damping device may be used to generate a torque which is added to a torque generated by the electric machine during an engine start. Consequently, the electric machine of this configuration may be designed with a lower power than an electric machine which does not use the work stored in the torsion damping device, thereby facilitating small construction space and low energy consumption on using the electric machine.
Model computations have shown that a simple single-disk clutch may present a construction space problem, particularly in high-performance vehicles. It may therefore be expedient to design the shift clutch of the inventive torque transmitting unit as a multiple-disk clutch to optimally utilize the construction space delimited by the rotor and stator of the electric machine.
With a view to a simple torsion damping device which works reliably, the connection of the torsion damping device between the primary mass and the secondary mass may be made by a torque input component and a torque output component with a spring device arranged between the torque input component and the torque output component. The spring device may be used, for example, as a work accumulator for the starting aid function described above.
To produce a compact torque transmission unit, the primary mass may comprise a carrying sleeve on which the secondary mass is rotatably mounted.
The primary and secondary masses may designed as sheet metal parts. Furthermore, the secondary mass may further comprise a guide sleeve rotatably mounted on the carrying sleeve of the primary mass.
For this purpose, the carrying sleeve has a stop for receiving an axial bearing point of the guide sleeve.
To simplify assembly, the guide sleeve may be produced in one integral piece with the rotor.
To simplify the design of the components, particularly with regard to forming work steps of forming sheet metal components, the guide sleeve may comprise a circumferential transmission profile which engages a counterprofile of the torque input component or the torque output component of the torsion damping device. The use of the circumferential transmission profile allows the torque components to be subdivided and also simplifies assembly. Furthermore, the profile connection between the circumferetial transmission profile and the counterprofile of the torque components may be used to achieve radial and axial tolerance compensation within the torsion damping device.
When the rotor of the electric machine is connected as part of the primary mass, the rotor may comprise a split design having multiple rotor segments in which one of the rotor segments is connected to the input shaft and another of the rotor segments is connected to the torsion damping device. This embodiment simplifies the connection of the rotor to the two functional components mentioned, namely the input shaft and torsion damping device.
To utilize the construction space within the stator and rotor of the electric machine in terms of maximum damping work of the torsion damping device, the torsion damping device may comprise a parallel arrangement of a plurality of spring devices. The torque input and torque output parts for each spring are combined to form a structural unit.
In a further embodiment, one of the torque components may comprise a cylindrical basic body having a first receiving portion and a second receiving portion at an axial distance from one another for guiding a first of the plural spring devices and at least a further receiving portion for guiding a second of the plural spring devices.
The basic
Link Achim
Reisser Wolfgang
Vogt Sebastian
Cohen & Pontani, Lieberman & Pavane
Lorence Richard M.
Mannesmann Sachs AG
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