Nested Gearbox Shafts for Compact Gear Selection and Engagement
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Solution Overview
Problem
Current control solutions for X-Y type gearbox operating systems are cumbersome and difficult to install in three-axis gearboxes, and the integration of electrical machines for hybridization is hindered by the presence of linear or rotary actuators.
Innovation Solution
A compact gearbox operating system with a first and second shaft, each with a respective actuator assembly, where the first shaft is hollow and fitted over the second shaft, allowing for independent axial translation and rotation, enabling separate selection and engagement of gears without the need for large control casings, and allowing for the integration of an electrical machine for mild hybridization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If linear or rotary actuators are used in the operating system, then the selection and engagement functions are achieved, but the overall dimensions increase and hybridization with electrical machines becomes problematical
Solution Approach 1:
The patent applies nesting by placing the second shaft (with engagement elements) inside the hollow first shaft (with selection elements). This nested configuration allows both selection and engagement functions to be integrated in a compact arrangement, eliminating the need for separate linear or rotary actuators and enabling future hybridization with electrical machines.
Solution Approach 2:
The operating system achieves multi-functionality by integrating both gear selection and engagement functions into a single compact mechanism. The first shaft handles selection movements while the second shaft handles engagement, both within the same spatial envelope, replacing traditional separate actuator systems.
2Reliability
If a traditional control casing is used to house the operating system, then all components are protected and integrated, but the installation becomes extremely problematical and space requirements increase
Solution Approach 1:
The patent segments the operating system into two independent shaft assemblies (first shaft with selection elements, second shaft with engagement elements) that can be manufactured and assembled separately. This segmentation simplifies installation in three-axis gearboxes while maintaining component protection and integration through the nested configuration.
3Ease of operation
If the operating system uses separate co-ordinates for selection and engagement, then the functions are clearly separated, but the kinematic chain becomes very cumbersome
Solution Approach 1:
The patent merges the selection and engagement kinematic chains by integrating them within the same nested shaft structure. The first shaft (selection) and second shaft (engagement) share the same spatial envelope and are coupled through the nested arrangement, simplifying the overall kinematic chain while maintaining functional separation.
Data Source
AI summary
Described herein is a system for operating a gearbox that includes: a first shaft having a first longitudinal axis; a first actuator assembly operatively connected to the first shaft; a second shaft having a second longitudinal axis; a second actuator assembly operatively connected to the second shaft; and a plurality of engagement elements connected in rotation to the second shaft. The first shaft is hollow, is fitted on the second shaft, and is axially movable relative to the second shaft. The plurality of engagement elements are moreover connected in translation to the first shaft and are axially movable therewith along the first longitudinal axis and relative to the second shaft. The first and second shafts can be operated independently of one another for execution of the movements of selection and engagement of the gears of the gearbox.