Gearbox with load distribution system

Abstract

A gearbox comprising: an input shaft (9) having first and second helical input gears (1, 2) of opposite hand fixed axially relative to each other and axially moveable in tandem; an output shaft (10); first and second lay shafts (7, 8) offset from the axis of the input shaft (9, 10) and configured to engage with the input and output shafts (9, 10) for transmitting rotational movement from the input shaft (9) to the output shaft (10), each lay shaft (7, 8) comprising an input gear (3, 4) such that the first lay shaft (7) engages with the first input gear (1) but not the second input gear (2) and the second lay shaft (8) engages with the second input gear (2) but not the first input gear (1 ),- and two or more output gears (26) rotatably mounted on, and selectively engageable with, the output shaft (10), the output gears being in continuous mesh with corresponding output gears (5, 6); on the first and second lay shafts (7, 8), wherein the gearbox is configured such that an imbalance in load sharing between the input shaft (9) and the first and second lay shafts (7, 8) when the output shaft (10) is engaged with the first and second lay shafts (7,8) results in axial movement of the first and second input gears (1, 2) tending to reduce the imbalance.

Description

technical field [0001] This invention relates to transmissions used to convert the torque and speed of a source of rotational power, such as an engine or other electric machine. Background technique [0002] Transmissions are commonly used in motor vehicles to allow the engine to operate within its operating limits while taking into account changes in vehicle speed. Gear pairs in transmissions are typically designed with backlash due to mechanical tolerances between the gears and thermal expansion of the gear teeth. Without a small amount of backlash, there is a risk of the transmission jamming under certain conditions. [0003] figure 1 The structure of a particular type of known variator, such as that described in document US 4,754,665, is shown exemplarily in . This type of transmission takes input rotational power from an input shaft 9 and transmits the input rotational power to a pair of countershafts 7 and 8 (also referred to as countershafts) through a head gear se...

AI Technical Summary

Problems solved by technology

However, the nature of the floating relationship between the gears 18, 19 on the main shaft makes this modification difficult because the synchronizers require tight tolerances to engage correctly

Therefore, the use of synchronizers has the risk of causing the transmission to jam due to the aforementioned problems related to the mechanical tolerances between the gears

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