Rotary Steering Gear Layout for Compact Heavy-Vehicle Packaging
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Solution Overview
Problem
Traditional steering systems for heavy-duty vehicles, such as trucks, require significant space in the under-hood environment due to their reliance on hydraulically powered RCB gears or worm and wheel steering systems, which also limit the implementation of electrically powered steering systems.
Innovation Solution
A completely rotary steering gear system that utilizes stacked gears and an electric motor to generate sufficient power for steering, eliminating linear movement and reducing the system's footprint, allowing for integration in various under-hood layouts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If hydraulic assist RCB steering systems or worm and wheel steering systems are used, then sufficient power is generated to steer heavy vehicles, but the system occupies significant space in the under-hood environment
Solution Approach 1:
The patent transitions from linear movement (hydraulic RCB or worm and wheel) to rotary movement only. The sector gear rotates continuously in the same plane as the pinion, eliminating the need for linear stroke space. This dimensional change allows the system to achieve sufficient steering power while occupying minimal under-hood space.
Solution Approach 2:
The stacked gear arrangement nests multiple gear assemblies (first gear assembly with first intermediate gear and pinion, second gear assembly with second intermediate gear and pinion) vertically one above another. This nesting approach allows multiple stages of torque multiplication to be packed into a compact vertical footprint, providing ample steering power while minimizing the horizontal space required in the under-hood environment.
2Power
If hydraulic assist RCB steering systems are used, then sufficient power is generated to steer heavy vehicles, but the system limits the implementation of electrically powered steering
Solution Approach 1:
The patent replaces traditional hydraulic assist RCB steering systems with an electrically powered rotary gear system. The electric motor directly drives the pinion gear, eliminating the need for hydraulic pumps, reservoirs, and RCB mechanisms. This substitution enables electrically powered steering while maintaining sufficient power delivery through the stacked gear reduction system.
Solution Approach 2:
The rotary steering system provides a universal platform that can be integrated into various under-hood layouts. The compact stacked gear arrangement can accommodate different motor positions, housing configurations, and vehicle architectures. This multi-functional design allows the same basic mechanism to serve different vehicle types and steering configurations, enhancing adaptability compared to dedicated hydraulic or worm-and-wheel systems.
3Ease of operation
If traditional steering systems are used, then steering function is achieved, but the system occupies significant space allowing limited integration of other vehicle systems
Solution Approach 1:
The stacked gear assemblies are arranged vertically in a compact nested configuration, with the first gear assembly positioned above the second gear assembly. This vertical nesting minimizes the horizontal footprint, creating space in the under-hood environment for additional vehicle systems such as air conditioning compressors, exhaust components, or electrical systems, while maintaining full steering functionality.
Solution Approach 2:
By changing from linear to rotary movement, the system eliminates the need for extensive linear space required by hydraulic RCB systems. The continuous rotary motion of the sector gear allows for a compact packaging that prioritizes vertical stacking over horizontal expansion, thereby freeing up space for other vehicle systems.
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 rotary steering system provides ample power to steer heavy vehicles while occupying less space, enabling the use of electrically powered steering and accommodating other vehicle systems in the under-hood environment.
Implementation Method 1
A motor is fixed to a third pinion. The third pinion is engaged with the second intermediate gear. The motor is to provide torque that rotates the input shaft, the first gear assembly, the second gear assembly, and the output shaft.
Implementation Method 2
A first intermediate gear is engaged with the input gear. A second intermediate gear is fixed to a second pinion. The second pinion is engaged with the first intermediate gear or a third intermediate gear. A third gear is fixed to a shaft. The third gear is engaged with the first pinion.
Data Source
AI summary
Rotary steering systems are disclosed. An example steering apparatus includes an input shaft including an input gear, an output gear fixed to an output shaft, a pitman arm coupled to the output shaft, the pitman arm to couple to a drag link to turn wheels of a vehicle as the output shaft rotates, an intermediate gear set including a first intermediate gear and a second intermediate gear, the first intermediate gear in contact with the input gear, the second intermediate gear in contact with the output gear, the first intermediate gear to rotate with the input gear, the second intermediate gear to rotate with the first intermediate gear, the output gear to rotate with the second intermediate gear.