Electric Axle Drive Chassis for Modular Heavy Offroad Trucks
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Solution Overview
Problem
Existing drivetrain solutions for heavy offroad trucks face issues such as harmful emissions, high weight, high center of gravity, complex and expensive components, and limited axle configurations, particularly with the use of internal combustion engines and fixed connections between gearbox and differential.
Innovation Solution
A chassis design for heavy offroad trucks featuring a central load-carrying tube with swinging half-axles and electric drive units, including an electric motor, auxiliary gearbox, and axis differential, allowing independent control of each axle, eliminating internal combustion engines and complex components, and enabling modular configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If internal combustion engine is used for propulsion, then power is provided, but harmful emissions (CO2 and NOx) are produced and weight increases
Solution Approach 1:
The patent replaces the internal combustion engine (mechanical/thermal system) with an electric motor (electrical system). The electric motor receives electrical energy from a power source and converts it directly to mechanical rotation to drive the wheels, eliminating the need for fuel combustion and thus eliminating harmful emissions while providing the necessary propulsion power.
2Power
If internal combustion engine and traditional drivetrain components are used, then propulsion is achieved, but drivetrain weight increases and center of gravity rises
Solution Approach 1:
The patent extracts and removes unnecessary heavy components from the traditional drivetrain system. Specifically, it eliminates the internal combustion engine, clutch, main gearbox, cardan shafts, and other intermediate transmission components, retaining only the essential elements (electric motor, auxiliary gearbox, and differential) needed to achieve propulsion. This extraction of non-essential components significantly reduces overall drivetrain weight.
Solution Approach 2:
The patent segments the drivetrain into independent modular units: the electric motor, the auxiliary gearbox, and the differential are treated as separate but integrated components. This segmentation allows for optimized placement and reduced overall system weight compared to the integrated traditional drivetrain, while also lowering the center of gravity.
3Power
If fixed connection between gearbox and differential is used, then torque is transferred, but installation space requirements increase
Solution Approach 1:
The patent employs a cardan shaft to connect the auxiliary gearbox to the differential, replacing the fixed rigid connection. This dynamic connection allows for angular misalignment and accommodates variations in installation space, enabling the drivetrain components to be positioned more flexibly within the vehicle chassis while still effectively transferring torque from the gearbox to the differential.
4Power
If cardan shafts are used for non-steered axles, then torque is transferred, but cost increases compared to rigid shafts
Solution Approach 1:
The patent applies different types of drive shafts based on the specific requirements of each axle position. Cardan shafts are used for non-steered axles where angular flexibility is needed, while rigid shafts are used for steered axles where precise alignment is required. This localized application of appropriate components optimizes the balance between performance and cost, avoiding the use of expensive cardan shafts where simpler rigid shafts suffice.
Data Source
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AI summary
Chassis, especially for heavy offroad truck, is fitted with drivetrain, wherein the chassis contains central load carrying tube (207) with at least two axles (6-9) with swinging half-axles, where the chassis has at least one drive unit assigned as part of the drivetrain. The drive unit consists of electric motor (201), with assigned auxiliary gearbox (202), connecting load carrying tube (203) and axis differential (18-21), wherein the drive unit is always assigned to only one axle (6-9).