Drive Shaft Press-Fit Connection for Crash Force Absorption
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Solution Overview
Problem
Existing drive shaft designs for motor vehicles fail to effectively absorb and transmit axial forces during crashes without causing damage, leading to potential buckling and penetration into the passenger cell.
Innovation Solution
A shaft connection comprising a metal shaft tube and a connecting element with an outer toothing pressed into the shaft tube, forming both circumferential and axial connections, allowing for the absorption and transmission of axial forces without damage by enabling telescopic movement upon exceeding a defined axial holding force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the drive shaft is designed to shorten axially in the event of a crash, then the drive shaft can prevent buckling and penetration into the passenger cell, but the shaft connection may suffer damage from excessive axial forces
Solution Approach 1:
The shaft tube is formed into the connecting element beforehand to create a controlled deformation zone. This pre-formed geometry allows the connection to absorb axial crash forces through controlled telescopic movement and deformation, preventing uncontrolled buckling while protecting the shaft connection from excessive damage
Solution Approach 2:
The shaft tube geometry is modified by forming it into the connecting element, changing its physical parameters (shape, volume, structural configuration). This transformed geometry enables the shaft tube to absorb axial forces through controlled deformation and telescopic movement, resolving the contradiction between crash safety and connection integrity
2Power
If a press fit connection is used between the connecting element and shaft tube, then torque transmission is achieved, but the connection cannot effectively absorb axial forces during crashes
Solution Approach 1:
The shaft tube-forming connection serves multiple functions: it maintains the press fit for torque transmission while simultaneously providing crash force absorption through controlled deformation. The formed geometry enables both rotational power transmission and axial force management, making the connection multi-functional
Solution Approach 2:
The connection transitions from a rigid press fit structure to a dynamic system where the shaft tube can deform and move telescopically during crashes. The formed geometry allows controlled movement and deformation under axial loads while maintaining torque transmission capability during normal operation
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 shaft connection effectively absorbs and transmits axial forces, maintaining integrity during crashes by allowing controlled telescopic movement, thus preventing damage and ensuring safe operation.
Implementation Method 1
a connecting element (3) made of a metal material, wherein the connecting element (3) has an outer toothing (6) which is pressed into a shaft tube (4) with a press fit
Implementation Method 2
the shaft tube (4) comprises an axial connection section (10) which is formed radially inwardly into the connecting element (3), such that an interlocking axial connection is formed between the shaft tube (4) and the connecting element (3) for transmitting axial forces
Implementation Method 3
energy is absorbed in the form of deformation work and friction when axial force is applied in the event of a crash along an increased displacement path
Implementation Method 4
energy is absorbed in the form of deformation work and friction when axial force is applied
Data Source
AI summary
A shaft connection, e.g., for a motor vehicle driveline, comprises a metal shaft tube material and a metal connecting element. The connecting element comprises a connecting portion with an outer toothing which is pressed with a press fit into a connecting portion of the shaft tube so that an interlocking connection effective in the circumferential direction is formed for torque transmission, wherein the connecting element comprises a maximum outer diameter in the region of the outer toothing; wherein the shaft tube comprises an axial connecting region which is formed radially inwardly into a section of the connecting portion that is reduced relative to the outer toothing so that an interlocking axial connection effective in the axial direction is formed between the shaft tube and the connecting element for transmitting axial forces. A drive shaft can have such a shaft connection.