Dual-Knuckle Suspension Layout for In-Wheel Motor Torque Steer
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Solution Overview
Problem
The integration of in-wheel motors in vehicles leads to a narrower wheel space and increased kingpin offset, causing torque steer phenomena that affect driving stability.
Innovation Solution
A suspension apparatus with a separated steering axis and suspension axis, featuring a first knuckle rotating around a first axis, a second knuckle moving along a second axis, a first suspension arm supporting the second knuckle, and a limiting member limiting its rotation, designed to counteract the effects of increased kingpin offset.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If in-wheel motors are installed inside wheels to expand interior space, then vehicle interior space is improved, but kingpin offset increases causing torque steer phenomena
Solution Approach 1:
The suspension system is divided into two separate knuckles: a first knuckle for steering rotation and a second knuckle for suspension movement. This segmentation allows the steering axis and suspension axis to be separated, reducing kingpin offset and eliminating torque steer while maintaining the in-wheel motor configuration for expanded interior space.
Solution Approach 2:
The first knuckle acts as an intermediary component between the drive unit and the second knuckle. It transmits steering input while the second knuckle handles suspension movement, allowing the steering axis to be separated from the suspension axis and reducing the harmful torque steer effect.
2Force
If kingpin offset is increased to provide braking force, then braking capability is improved, but torque steer phenomenon occurs affecting driving stability
Solution Approach 1:
By separating the steering function (first knuckle) from the suspension and braking function (second knuckle), the system reduces kingpin offset. This allows braking force to be effectively transmitted through the second knuckle while minimizing the torque steer that would otherwise compromise driving stability.
3Object-generated harmful factors
If steering axis and suspension axis are separated, then torque steer is reduced, but device complexity increases
Solution Approach 1:
The first knuckle and second knuckle are connected to form an integrated assembly that combines steering and suspension functions. While the internal structure is segmented, the overall design merges these functions into a compact unit that reduces kingpin offset without proportionally increasing external complexity.
Solution Approach 2:
The first knuckle serves multiple functions: it acts as a steering pivot, connects the drive unit to the second knuckle, and provides structural support. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity despite the separated axis design.
Data Source
AI summary
A suspension apparatus and a suspension apparatus for a vehicle are provided. The suspension apparatus includes a drive unit installed inside a wheel, a first knuckle connected to the drive unit and configured to rotate around a first axis, a second knuckle connected to the first knuckle and configured to move along a second axis spaced apart from the first axis, a first suspension arm connected to the second knuckle and configured to support the second knuckle with respect to a vehicle body, and a limiting member connected to the first suspension arm and configured to limit rotation of the second knuckle around the second axis.