Known in the art is an intermediate gear transmission such as a double clutch transmission, automatic shift transmissions, manual shift transmissions, or the like. These are generally configured and built by mounting rotating gear wheels on a shaft which are interconnecting with fixed gear wheels on an additional shaft, forming the so called gear wheel pairing. Through the interchangeable, fixed connections with the wheels which rotate on the shaft, the pairing of different gear shift positions in the intermediate transmission and its related flow of force in the intermediate transmission can be achieved by adding switching elements such synchronization devices or claw or friction elements.
The activation of the switching elements, needed to shift the required gear pair configurations, takes place on the related shaft where the gear wheels, such as idle gears, are loosely positioned in the intermediate gear transmission, either mechanically, hydraulically, pneumatically, or magnetically, from either the outside or the inside.
The documents of DE 102 06 584 A1, DE 43 25 964 A1, and DE 103 02 502 A1 present the general state of the art, in view of operating the switching elements, in regard to operating the switching elements, from the inner section of the shaft to enable or disable the idle gear wheels or gear wheel pairing, respectively.
The external activation of the switching elements, in an intermediate transmission, is usually achieved via a shift fork or a similar device, whereby the activation of the switching elements from the inner part of the shaft, which carries the idle gear wheels, require less space when compared to activation of idle gear wheels and required shaft surface from the outside, because the switching configuration is located in the inside of the shaft, requiring also less space in the radial direction. To the contrary, intermediate transmissions with an inner activation mechanism of the idle gear wheels require more space in comparison to intermediate transmissions with an external activation of the switching elements in the axial direction.
This is based on the application of an activation force and directing it to the switching elements located in between the idle gear wheels, in order to activate the idle gear wheels and switching elements in the inner part of the shaft which also carries the idle gear wheels. Since neither the width of the bearings of the idle gear wheels located on the shaft nor the switching elements space requirements can be altered, and the directional guidance of the activating force through the shaft is very limited, the internal activation of the switching elements of the shaft has to be achieved in areas which are not functionally utilized by the idle gear wheels or the switching elements. As a result, available unused areas of the shaft are needed which can only be made available by extending the length of the shaft.
USPTO Backgrounds
USPTO Backgrounds