Urban Bus Wheel Diameter and Modular Electric Drive
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Urban transport vehicles with large wheels face challenges in passenger comfort and accessibility due to raised sections for wheel arches, limiting the size of the central corridor and requiring complex drive systems that are not modular or efficient.
Innovation Solution
The use of wheels with a smaller diameter (700-750 mm) allows for a simplified, modular structure with a larger central corridor and compact high-efficiency drive systems, eliminating the need for raised sections and enabling easier movement and accessibility, while maintaining sufficient load capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If large wheels are used in urban transport vehicles, then the vehicle can support heavy loads and maintain stability, but the wheel arches require raised sections that reduce central corridor size and passenger comfort
Solution Approach 1:
The patent applies parameter changes by reducing the wheel diameter from conventional large sizes to specifically 765 mm, and further optimizing to 700-750 mm. This parameter change allows the wheel arches to be lowered, eliminating raised sections and improving central corridor accessibility while maintaining sufficient load capacity through optimized wheel and suspension design.
2Power
If complex drive systems are used to accommodate large wheels, then the vehicle can maintain power and torque, but the structure becomes non-modular and less efficient
Solution Approach 1:
The patent applies segmentation by dividing the drive system into modular components: electric motors, reduction gears (with ratios of 5-8), and differential mechanisms. Each module can be independently optimized and assembled, enabling standardized configurations that maintain high power and torque while improving modularity and efficiency. The reduction gear stages are clearly segmented to achieve the required torque multiplication.
Solution Approach 2:
The patent replaces conventional mechanical drive systems with electric motors directly coupled to the wheels through reduction gears. This substitution eliminates complex mechanical transmissions, clutches, and shafts, resulting in a simpler, more efficient, and modular electric drive system that maintains high power output while reducing structural complexity.
3Ease of operation
If small wheels are used, then the structure is simplified and central corridor is enlarged, but the load capacity may be compromised
Solution Approach 1:
The patent optimizes the wheel diameter parameter to 700-750 mm (with 765 mm as a specific embodiment), which is smaller than conventional wheels but large enough to maintain adequate load capacity. This optimized parameter allows the wheel arches to be lowered for improved accessibility while the wheel size remains sufficient to support the vehicle and passenger load through proper structural design.
Solution Approach 2:
The patent utilizes the spherical geometry of the wheels to maximize load distribution. By optimizing the wheel diameter and incorporating curved, ergonomic seat designs that follow the wheel arch contours, the system achieves efficient load bearing with smaller wheels, maintaining strength while improving space utilization and accessibility in the central corridor.
Data Source
Figure 1~5
Figure 6
Figure 7
AI summary
This urban transport vehicle, of the bus type, comprises a body mounted on axles, each axle having at least two wheels placed either side of the body, the transport vehicle having a total live load of more than 5 metric tons and an overall length of more than 5.5 metres, characterised in that the wheels of at least one axle have a diameter of between 700 and 750 mm, each wheel being driven by an electric motor (21) with at least two stages of reduction gears (27,37) being provided between this motor and the wheel.