Motor Vehicle Drive Shaft Crash-Mode Segmentation
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Solution Overview
Problem
Motor vehicle drive shafts lack a defined failure mechanism in the event of a crash, which can lead to unintended reinforcement of the vehicle in the longitudinal direction, compromising safety and operational behavior.
Innovation Solution
A motor vehicle drive shaft design featuring a receptacle-tube component and a push-fit component with a friction-fitting/form-fitting connection that transitions from a torque-transmitting state to a crash state upon predefined longitudinal loading, where the push-fit component is partially pushed into the receptacle-tube component, enabling controlled failure and high torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the drive shaft is designed with high strength and rigidity to transmit high drive forces, then torque transmission capability is improved, but the drive shaft becomes excessively reinforced in the longitudinal direction during a crash
Solution Approach 1:
The drive shaft is divided into multiple components: a first drive shaft component, a second drive shaft component, and a connection component. This segmentation allows the torque transmission function to be maintained through the connection component while the individual segments can move relative to each other during a crash, preventing excessive longitudinal reinforcement.
Solution Approach 2:
The connection component acts as an intermediary element between the first and second drive shaft components. It transmits torque during normal operation but allows controlled relative movement during a crash, serving as a mediator that balances torque transmission capability with crash safety requirements.
2Power
If the drive shaft components are rigidly connected to maximize torque transmission, then power transmission efficiency is improved, but the drive shaft lacks a defined failure mechanism in the event of a crash
Solution Approach 1:
The connection between drive shaft components transitions from a static rigid connection to a dynamic system. The connection component allows the drive shaft to adapt its stiffness characteristics based on loading conditions: rigid during normal operation for efficient torque transmission, and flexible during crash to enable controlled failure.
Solution Approach 2:
The effective stiffness parameter of the drive shaft changes based on the state of operation. During normal operation, the connection component maintains a rigid connection for high torque transmission. During crash, the connection allows relative movement, effectively changing the stiffness parameter to enable controlled failure and energy absorption.
3Strength
If the push-fit external diameter is made equal to the receptacle internal diameter for tight fit, then connection strength is improved, but the push-fit component cannot be partially pushed into the receptacle-tube component during crash
Solution Approach 1:
The connection component has different local properties: a first connection region with a first diameter that provides strong torque transmission, and a second connection region with a second diameter that is smaller than the receptacle internal diameter, allowing longitudinal displacement during crash. This local quality differentiation resolves the contradiction between connection strength and crash displacement capability.
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
The design ensures a controlled failure mechanism during crashes, maintaining vehicle safety by preventing excessive longitudinal reinforcement while allowing high torque transmission and favorable crash behavior.
Implementation Method 1
The connection component conjointly with the receptacle-tube component configures a receptacle connection for the transmission of torque
Implementation Method 2
the connection component, in particular radially on the outside, has a knurling
Implementation Method 3
the push-fit component in the longitudinal direction is at least partially pushed into the receptacle-tube component
Implementation Method 4
at least one of the previously mentioned connections (push-fit connection, receptacle connection), is destroyed in particular on account of a loading of the motor vehicle drive shaft in the longitudinal direction
Data Source
AI summary
A motor vehicle drive shaft has a receptacle tube component with a receptacle internal diameter and a push-fit component with a push-fit external diameter. The push-fit external diameter is smaller than or equal to the receptacle internal diameter. The receptacle tube component and the push-fit component can be rotated about a common drive shaft rotational axis and extend along the latter in a longitudinal direction. The receptacle tube component and the push-fit component are connected to one another for the transmission of torque. A connecting component is provided, wherein the connecting component is connected in a torque-conducting manner to the receptacle tube component by way of a receptacle connection. The connecting component is connected to the push-fit component by way of a push-fit connection. At least one of the two connections is configured as a combined frictionally locking and positively locking shaft/hub connection.