Machine element or mechanism – Gearing – Interchangeably locked
Reexamination Certificate
2001-07-14
2003-10-21
Estremsky, Sherry (Department: 3681)
Machine element or mechanism
Gearing
Interchangeably locked
C074S330000, C074S661000, C477S006000, C477S008000
Reexamination Certificate
active
06634247
ABSTRACT:
The invention relates to a gearbox, particularly for a motor vehicle, with multiple shafts such as a first and a second gear input shaft and a gear output shaft as well as a multitude of gear pairs between the gear output shaft and the gear input shafts, consisting of an idler that is arranged around one of the shafts, respectively, and connected with it in a stationary manner, and a fixed wheel that is arranged in a stationary manner on a corresponding shaft so as to comb with the idler for the purpose of forming gears with different gear ratios between the gear input shaft and one of the gear output shafts.
Such gears are basically known particularly in connection with internal combustion engines and the separation of the gear input shafts through a clutch of the crankshaft and represent the state of the art for the task of further developing and automating these gearboxes. One aspect of the task is to manufacture this gearbox in the automatic version in a cost effective manner, another aspect of the task is the economical operation of a drive branch with such a gearbox. Furthermore, a partial aspect of the task consists of creating a method for the ecological and comfortable operation of a motor vehicle with a gear box pursuant to the disclosed application documents.
This task is resolved with a gearbox, particularly for motor vehicles, with a multitude of shafts such as a first and a second gear input shaft and an output shaft, which in a beneficial version can also be formed by two shaft branches that can be united later one, for example, with a differential or toothed wheel work, with this gearbox being equipped with at least the following features:
a) a multitude of gear pairs is arranged between the gear output shaft and the gear input shafts, consisting of an idler that is arranged around one of the shafts, respectively, and connected with it in a stationary manner, and a fixed wheel that is arranged in a stationary manner on a corresponding shaft so as to comb with the idler for the purpose of forming gears with different gear ratios between the gear input shaft and one of the gear output shafts;
b) at least one gear input shaft can be driven at least in part through a drive unit with a drive shaft;
c) at least one gear input shaft can be connected with a first electric unit;
d) the gear output shaft can be connected with at least one driving wheel;
e) at least one gear can be actuated automatically with an actuator.
For this embodiment, the idler and fixed wheels that are formed by the gear pairs can be arranged on the gear input shafts and/or the gear output shaft, wherein it may be beneficial to arrange the idlers on the gear input shafts, respectively. Furthermore, it may be beneficial for other embodiments to arrange the idlers on the gear output shaft, particularly in transmissions where the appropriate fixed wheels can be arranged rationally on the gear input shafts because their diameter can be designed so small that they can be easily manufactured in a firmly connected version or single-piece version through forging, milling, stamping processes, through hot flow processes such as lateral extrusion or similar processes. The drive unit can be formed by an internal combustion engine, for example, a piston engine with crankshaft, with appropriate devices being provided for dampening torsional oscillation, axial and/or wobble oscillation between the internal combustion engine and the transmission. Furthermore, the drive unit can be formed by a second electric unit, wherein the first as well as the second electric unit, which can also be operated in a polyphase manner as an electric engine and/or generator based on the synchronous, asynchronous and/or reluctance principle, can drive one gear input shaft, respectively, and can have roughly the same dimensions. Particularly in connection with the usage of an internal combustion engine as the drive unit, it is particularly beneficial to design its drive shaft so that it can be coupled with the gear input shafts, wherein at least one gear input shaft, preferably both, can be coupled with the drive shaft. One embodiment in accordance with the invention provides for a design where the clutches are friction clutches, preferably dry friction clutches, in the form of a double clutch, with this being possibly arranged in the clutch housing of the gearbox, i.e. axially between the drive unit and the transmission. For this version, the previously mentioned dampening devices can be integrated in the double clutch, furthermore a flywheel that may be provided can hold the clutches, wherein the various clutch components can be fastened to the flywheel as modules and the flywheel can be a divided flywheel with two-mass effect.
Based on one inventive idea, the drive unit can furthermore be formed by an internal combustion engine with a crankshaft that can be connected with one gear input shaft, respectively, through a double clutch. For this purpose, an electric unit—such as the one described above as the first electric unit—can be connected additionally with at least one gear input shaft in such a manner that it can be uncoupled. It can also prove particularly beneficial to arrange the electric unit so as to allow it to be connected alternatively with both gear input shafts. This connection can be formed by a friction, shifting or magnetic clutch, which creates the connection from the electric unit to the gear input shaft by building up electro-magnetic fields, wherein the formation of the connection and/or the selection of this clutch can occur through an actuator of the electric, hydraulic and/or pneumatic as well as a combined procedure or in the case of a magnetic clutch through the appropriate selection of the electric currents through the device adjusting the magnetic effect, such as coils or similar devices. Of course, two clutches can also be beneficial for forming a connection between the gear input shafts and the electric unit that can be uncoupled, wherein one clutch, respectively, can connect the electric unit with one of the gear input shafts and two appropriate actuators can be used for this purpose.
Beneficial embodiments of the gearbox provide for the fact that the gear output shaft can be arranged basically coaxially to the drive shaft and/or that one of the gear input shafts is arranged basically coaxially to the drive shaft. It can prove particularly beneficial to arrange one gear input shaft as a hollow shaft around the other gear input shaft. In a beneficial version, the gear pairs that form the individual gears can be arranged alternating on the two gear input shafts in dependence of the gear ratios. This way it is possible to operate the vehicle through a gear input shaft, which is connected with the internal combustion engine through the appropriate clutch, and a gear with one gear ratio, while on the other gear input shaft the next gear ratio is engaged with an engaged clutch between the gear input shaft and the internal combustion engine. This way, for example, four, preferably six, separate forward speeds and one reverse speed can be incorporated in these transmissions, wherein those gears with an increasing gear ratio can be arranged on one gear input shaft and those gears with gear ratios in between the gear ratios of that on the first gear input shaft can be arranged on the other gear input shaft. The reverse gear can be arranged on either of the two gear input shafts. In an alternative to this embodiment, the motor vehicle can be operated purely electrically in reverse, wherein the electric unit is operated in the opposite rotational direction. The preferred starting gear with the smallest gear ratio can, for example, be arranged on the first one, the second gear with the next higher gear ratio on the second one, the third gear again on the first one and the fourth gear again on the second one etc. The electric unit can be connected with the gear input shaft that contains the gear with the smallest or the gear with the next smaller gear ratio. The individual gears are preferably formed through fixed
Berger Reinhard
Fischer Robert
Pels Thomas
Reik Wolfgang
Reitz Dierk
Estremsky Sherry
Lewis Tisha D.
Luk Lamellen und Kupplungsbau Beteiligungs KG
Mangels Alfred J.
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