Steering Column Electric Adjustment with Single Gear Rack
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Solution Overview
Problem
Existing adjustable steering columns for motor vehicles are complex, require multiple components, and compromise on strength and rigidity due to design limitations, particularly in achieving long adjustment paths and stability during crashes.
Innovation Solution
A compact, electrically adjustable steering column design featuring a gear rack on the outer face of the jacket tube, a reduction gear between the electric motor and worm gear, and an energy absorption device, such as a bending wire or sliding block, to enhance strength, rigidity, and crash resistance with reduced component count and installation space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a plurality of gear racks are used to achieve longitudinal adjustment, then the adjustment function is achieved, but the device complexity increases
Solution Approach 1:
The invention extracts the adjustment function from multiple gear racks and concentrates it into a single gear rack that works with a worm gear. The worm gear engages with the single gear rack to provide the longitudinal adjustment function, eliminating the need for multiple gear racks while maintaining the adjustment capability.
Solution Approach 2:
The invention combines the adjustment function that previously required multiple gear racks into a single integrated system consisting of one gear rack and one worm gear. This merging reduces the number of components while achieving the same longitudinal adjustment effect.
2Ease of operation
If rolling elements are used to mount the jacket tube on the guide box, then the jacket tube is mounted, but the bearing structure becomes complex
Solution Approach 1:
The invention removes the complex rolling element bearing structure and replaces it with a simpler mounting arrangement. The jacket tube is mounted on the guide box without requiring intricate bearing mechanisms, thereby simplifying the overall structure while maintaining the mounting function.
3Reliability
If a reduction gear with multiple components is used to guarantee longitudinal adjustment, then the adjustment reliability is improved, but the device complexity increases
Solution Approach 1:
The invention merges the reduction gear functionality into a more compact configuration that works in conjunction with the worm gear and single gear rack. This integration maintains the reliability of longitudinal adjustment while reducing the total number of separate components required.
4Ease of operation
If the outer jacket tube is provided with an opening for the worm gear, then the worm gear can be connected, but the stability of the jacket tube is weakened
Solution Approach 1:
The invention extracts the worm gear connection from the outer jacket tube structure, eliminating the need for openings in the outer tube. The worm gear is connected in a manner that does not require compromising the integrity or stability of the outer jacket tube.
5Volume of moving object
If the installation space between inner and outer jacket tubes is limited, then the structural constraints are reduced, but the configuration options for toothing are limited
Solution Approach 1:
The invention addresses the limited installation space by optimizing the spatial arrangement of the gear rack and worm gear within the constrained volume. The toothing configuration is designed to fit within the limited space while maintaining functional effectiveness, utilizing the available dimensional space efficiently.
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 solution enables longer adjustment paths beyond 150 mm with improved strength and rigidity, reduced noise, and effective energy absorption during crashes, maintaining structural integrity and reducing the risk of component failure.
Implementation Method 1
a worm gear (11) which meshes with the toothing (9, 10, 29) of the gear rack
Implementation Method 2
a reduction gear (13) arranged in an operative manner between the electric motor (8) and the worm gear (11)
Implementation Method 3
an energy absorption device, such as a bending wire or sliding block, to enhance strength, rigidity, and crash resistance
Data Source
AI summary
An adjustable steering column for a motor vehicle may comprise a rotatable steering shaft that has a shaft part that can be displaced axially along its axis of rotation. The shaft part may be rotatably mounted in a jacket tube that is mounted in an axially sliding manner in a guide box held on a retaining part fixed to the vehicle body and can be displaced by means of an electric motor. The adjustable steering column is improved with respect to a small installation space of the electrical adjustment in conjunction with high strength of the steering column. A gear rack may be attached to an outer face of the jacket tube. Also, the electric motor may be fastened to the guide box and may drive a worm gear that protrudes through an opening in the guide box towards the jacket tube and meshes with the gear rack.