Four-Wheel Drive Layout With Coaxial Epicyclic Differentials
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Solution Overview
Problem
Existing four-wheel drive cars face challenges in achieving optimal mass distribution with the center of gravity positioned centrally and low to the road surface, which affects traction and aerodynamic efficiency.
Innovation Solution
A four-wheel drive car design with a centrally positioned internal combustion engine, a dual-clutch gearbox aligned with the engine, and epicyclic differentials that distribute torque efficiently to all wheels, allowing for a compact layout with the engine's center of gravity low and close to the road surface, and a large rear aerodynamic extractor for improved aerodynamics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the engine and transmission system are positioned to achieve four-wheel drive functionality, then traction is improved, but the center of gravity position and mass distribution deteriorate
Solution Approach 1:
The transmission shaft is positioned beneath the engine, utilizing the vertical space between the engine and road surface. This dimensional arrangement allows the torque distribution mechanism to operate in the vertical dimension rather than occupying horizontal space, thereby maintaining optimal mass distribution while achieving four-wheel drive traction.
Solution Approach 2:
The transmission shaft is nested within the space between the engine and the road surface, with the epicyclic differentials integrated into this compact arrangement. This nesting approach allows the four-wheel drive mechanism to be contained within the existing engine bay volume without compromising mass distribution or requiring additional external components.
2Reliability
If a traditional four-wheel drive transmission system is implemented, then torque distribution to all wheels is achieved, but the wheelbase length increases
Solution Approach 1:
By positioning the transmission shaft beneath the engine and utilizing vertical space, the system eliminates the need for extended transmission lines that would increase the wheelbase. The torque distribution mechanism operates in the vertical dimension, keeping the horizontal footprint compact and maintaining a short wheelbase.
Solution Approach 2:
The invention extracts the torque distribution function from the traditional horizontal transmission line and relocates it to a vertical arrangement beneath the engine. This separation of the torque distribution function from the main transmission path allows for independent optimization of both torque distribution capability and wheelbase length.
3Object-affected harmful factors
If the center of gravity is positioned low for aerodynamic efficiency, then aerodynamic performance is improved, but the mechanical component layout becomes constrained
Solution Approach 1:
The transmission shaft and epicyclic differentials are arranged in the vertical dimension beneath the engine, utilizing the space between the engine and road surface. This vertical arrangement allows the center of gravity to be positioned low for aerodynamic efficiency while the mechanical components are stacked vertically rather than spread horizontally, simplifying the overall layout.
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 design achieves optimal mass distribution, enhanced traction, and improved aerodynamic efficiency by positioning the engine centrally, minimizing the wheelbase, and incorporating a large rear aerodynamic chute, resulting in high-performance dynamic behavior.
Implementation Method 1
epicyclic differentials that distribute torque efficiently to all wheels
Data Source
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AI summary
Car (1) having: a first axle having two first drive wheels (2); a second axle having two second drive wheels (3); an internal combustion engine (4), which is provided with a plurality of cylinders (8), where respective pistons (9) slide on the inside, and with a drive shaft (10) connected to the pistons (9) and oriented longitudinally; a transmission shaft (25), which is oriented longitudinally and is configured to transmit the motion from the internal combustion engine (4) to the first wheels (2); a gearbox (16) provided with at least one primary shaft (18), which receives the motion from the drive shaft (10), and with at least one secondary shaft (19); a first epicyclic differential (22), which receives the motion from the secondary shaft (19) of the gearbox (16) and transmits the motion to the first wheels (2) through the transmission shaft (25) and to the second wheels (3); and a second epicyclic differential (23), which is coaxial to the two second wheels (3), is interposed between the first epicyclic differential (22) and the second wheels (3), receives the motion from the first epicyclic differential (22) and transmits the motion to the second wheels (3). The two differentials (22, 23) are arranged coaxial to each other.