Two-Wire Differential Locking State Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional differentials fail to effectively manage torque distribution on slippery surfaces, leading to vehicle immobilization, and existing limited-slip differentials are not actively controllable with anti-lock braking systems or traction control systems.
Innovation Solution
A locking differential with an actuator and sensor assembly that can be actively controlled to place the differential in an 'open' or 'locked' condition, using a solenoid assembly and Hall effect sensors to detect the locking state, allowing independent wheel speed control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical limited-slip differential is used, then traction on slippery surfaces is improved, but compatibility with anti-lock braking systems deteriorates
Solution Approach 1:
The patent replaces the purely mechanical limited-slip differential mechanism with an electronically controlled system. An actuator (electric motor or solenoid) is introduced to actively control the locking mechanism, allowing the differential to be integrated with vehicle electronic control systems like anti-lock braking and traction control systems. This substitution enables the differential to respond to electronic control signals rather than relying solely on mechanical force thresholds.
Solution Approach 2:
The differential locking mechanism is made dynamically controllable through an actuator that can adjust the locking state in real-time based on vehicle operating conditions. The system transitions from a static mechanical limitation to a dynamic control system that can actively engage and disengage the locking mechanism as needed, providing adaptability to different driving scenarios and control system requirements.
2Reliability
If a mechanical limited-slip differential is used, then speed differentiation limitation is achieved, but active control capability deteriorates
Solution Approach 1:
The patent replaces passive mechanical speed differentiation limitation with an actively controlled system. An actuator is introduced to dynamically adjust the differential locking mechanism based on control signals from vehicle control systems, enabling active control capability while maintaining speed differentiation limitation when needed.
Solution Approach 2:
The patent incorporates sensors (such as Hall effect sensors or magnetic sensors) to detect the rotational speeds of the left and right wheels and provide feedback to the control system. This feedback mechanism enables the control system to monitor the differential's operation and actively adjust the locking mechanism to achieve desired speed differentiation control, transitioning from passive mechanical control to active feedback-based control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables improved traction control and compatibility with anti-lock braking systems by actively managing differential locking, enhancing vehicle stability on slippery surfaces.
Implementation Method 1
A sensor assembly including a Hall effect sensor and a magnet is mounted to the differential case
Implementation Method 2
The sensor assembly is operable to provide a signal indicating whether the differential assembly is in a locked or open condition
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An axle assembly includes a housing, a first shaft rotatably positioned in the housing, and a second shaft rotatably positioned in the housing. A power transfer mechanism is also positioned in the housing and operable to selectively transmit rotary power between the first and second shafts. An actuator having a linearly moveable member is operable to drivingly engage the moveable member with the power transfer mechanism to cause power transmission between the first and second shafts. A sensor circuit is positioned within the housing and operable to output a signal indicative of the linear position of the moveable member. The sensor circuit includes first and second Hall effect devices electrically connected such that only two electrical terminals extend through the housing.