Steer-by-Wire Torque Limiter with Elastic Damping
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Solution Overview
Problem
Steer-by-wire steering systems require a mechanical stop to limit the steering wheel's rotation to 720 degrees, which existing solutions fail to achieve effectively and reliably, leading to inconsistent steering performance and potential damage from excessive rotation.
Innovation Solution
A mechanical stop device comprising a cylinder-shaped control piece, blocking pieces, guide links, and a housing that engages with the steering shaft, allowing proportional movement to limit the steering shaft's rotation to 720 degrees by using a link pin and guide link mechanism, with optional spiral guide links and elastic damping elements for enhanced reliability and acoustic damping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical stop is implemented to limit steering shaft rotation to 720 degrees, then steering safety and reliability are improved, but device complexity increases due to additional components like blocking pieces, guide links, and control pieces
Solution Approach 1:
The mechanical stop is divided into separate functional components: a control piece that rotates with the steering shaft, blocking pieces that engage with the control piece, and guide links that connect them. This segmentation allows each component to perform its specific function while maintaining overall system reliability without requiring a monolithic complex structure.
Solution Approach 2:
The guide link acts as an intermediary element between the control piece and blocking piece, transforming the rotational movement of the steering shaft into the blocking action. This intermediary mechanism simplifies the connection between moving parts and ensures reliable engagement at the maximum rotation angle.
2Reliability
If blocking pieces are made to engage firmly with the control piece to ensure reliable stopping, then steering reliability is improved, but impact forces are transmitted to the steering housing causing damage
Solution Approach 1:
Elastic damping elements are installed in advance within the housing to cushion and absorb impact forces when the blocking pieces engage with the control piece. This beforehand cushioning prevents harmful forces from being transmitted to the steering housing while maintaining reliable stopping action.
Solution Approach 2:
The elastic damping elements convert the harmful impact forces generated during blocking engagement into beneficial elastic deformation energy, absorbing the shock and preventing damage to the steering housing while maintaining the reliability of the stopping mechanism.
3Manufacturing precision
If the guide link is designed in a spiral manner to transform rotary movement into proportional linear movement, then steering precision is improved, but manufacturing complexity increases
Solution Approach 1:
The guide link is designed with a spiral curvature that transforms the rotary movement of the control piece into proportional linear movement of the blocking piece. This curved geometry provides precise movement transformation while the spiral form can be efficiently manufactured using standard forming processes.
Data Source
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AI summary
The invention relates to a device for limiting the rotation of the steering shaft (4) of a steer-by-wire steering system of a motor vehicle, comprising a housing (1, 6) that receives a control piece (2, 7) and at least one locking piece (3, 8) engaging with it, wherein the control piece (2, 7) is rotatably mounted in the housing (1, 6), has at least one guide cam (221, 73), at least one stop (212, 72) and an axial receptacle for the positive engagement of a drive element of the steering shaft (4), and wherein the locking piece (3, 8) is pivotably or slidably mounted in the housing (1, 6) and has at least one cam pin (31, 83) that engages in a guide cam (221, 73) of the control piece (2, 7) and is movable via this such that a stop surface arranged on the at least one locking piece (3, 8) a defined rotational position of the control piece (2, 7) is against its stop (212, 72).