Non-Circular Steering Gearing for Clean Cornering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing steering devices for vehicles, particularly transport vehicles, face limitations in achieving clean cornering without wheel erasing and enabling transverse travel, as they often require additional electric drives or restrict curve radii and sideways movement.
Innovation Solution
A steering device with non-circular gearing and a transfer function that links steering angles to wheel rotations, using a combination of trigonometric functions and polynomials to adjust gear ratios, allowing for smooth cornering and transverse movement without wheel erasing, by ensuring continuous derivatives and optimal alignment of wheels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-circular gearing with transfer functions is used, then cornering without wheel erasing is achieved, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by using non-circular gearing where the gear ratio varies continuously with the steering angle. The transfer functions (trigonometric for small angles, polynomial for larger angles) dynamically adjust the relationship between steering element rotation and wheel rotation, enabling clean cornering without wheel erasing while managing the complexity through mathematical modeling.
2Adaptability or versatility
If additional electric drives are used for rear wheels, then transverse travel is enabled, but device complexity and cost increase
Solution Approach 1:
The patent achieves multi-functionality by designing a mechanical transmission system that can perform multiple steering functions (cornering and transverse travel) using a single integrated mechanism. The non-circular gearing and transfer functions enable the same transmission device to achieve different wheel orientations depending on the steering input, eliminating the need for separate electric drives for rear wheels.
3Reliability
If eccentric sprockets are used, then cornering is improved, but the common intersection of rolling axes cannot be ensured over wide swivel range
Solution Approach 1:
The patent applies dynamics by transitioning from static eccentric sprockets to a dynamic non-circular gearing system. The gear ratio and tooth profiles are designed to change continuously with the steering angle, allowing the rolling axes to maintain a common intersection point dynamically throughout the entire swivel range, not just at specific positions.
4Device complexity
If only one axle is steered, then device complexity is reduced, but narrow curve radii and transverse travel are not possible
Solution Approach 1:
The patent applies segmentation by dividing the steering control into multiple independent controllable elements (front and rear wheels or axles) that can be steered differently. This allows the system to achieve complex maneuvers like narrow curve radii and transverse travel by coordinating the steering of segmented wheel groups, while maintaining relative simplicity through the use of a unified mechanical transmission mechanism.
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3a~3b
AI summary
The invention relates to a steering device (3) for a vehicle (1), in particular a transport cart, comprising at least a steering element (5) and a transferring apparatus (31, 39, 47, 51) for transferring a steering motion of the steering element (5) to at least a first wheel (7), wherein the first wheel (7) is supported in such a way that the first wheel can be turned about at least a first steering axis (15) and can be rotated about at least a first axis of rotation (23) extending perpendicularly to the first steering axis (15) and the transferring apparatus has at least a first first gear (39), which is mechanically operatively connected to the steering element (5) and has at least a noncircular arrangement of teeth, and at least a first second gear (31), which is mechanically operatively connected to the first wheel (7) and which comprises a noncircular arrangement of teeth complementary to the noncircular arrangement of teeth of the first first gear (39), wherein a motion of the steering element (5) from a position corresponding to straight-ahead travel of the vehicle (1) to a position corresponding to cornering of the vehicle (1) in a direction of a first angle (α) leads to a turning of the first wheel (7) about the first steering axis (15) by a first second angle (γ) from a position of the first wheel (7) corresponding to the straight-ahead travel of the vehicle (1), wherein furthermore the first angle (α) and the second angle (γ) are linked to each other by means of at least a first transfer function, wherein for a first angular range of the first angle (α), the first transfer function is a first trigonometric function, and for a second angular range of the first angle (α), the first transfer function is a first polynomial of the nth degree, with n ≥ 2, and to a vehicle having a steering device according to the invention.