Straddle Electric Vehicle Motor Case Frame Rigidity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Straddle electric vehicles face a trade-off between increasing vehicle body frame rigidity for improved performance and reducing weight, which negatively affects fuel efficiency.
Innovation Solution
A straddle electric vehicle design featuring a vehicle body frame with a motor case that includes a motor accommodating portion, a front fixing portion, an upper-rear fixing portion, and a lower-rear fixing portion, where the motor driving shaft is located within a virtual triangle defined by these portions, enhancing rigidity while minimizing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the rigidity of the vehicle body frame is increased for performance improvement, then traveling stability and turning operability are improved, but the weight of the vehicle body frame increases and fuel efficiency deteriorates
Solution Approach 1:
The motor case is merged with the vehicle body frame structure by integrating the motor accommodating portion, front fixing portion, upper-rear fixing portion, and lower-rear fixing portion into a unified assembly. This merging allows the motor case to serve dual purposes: housing the electric motor and providing structural support to enhance frame rigidity, thereby eliminating the need for separate reinforcement components and reducing overall vehicle weight.
Solution Approach 2:
The motor case is designed with multi-functionality, serving both as the housing for the electric motor and as a structural component of the vehicle body frame. The fixing portions extend into the motor case to provide mounting points that reinforce the frame structure, allowing a single component to fulfill multiple functions: motor accommodation, structural support, and rigidity enhancement, thus avoiding additional weight from separate structural reinforcements.
2Stability of the object's composition
If the rigidity of the vehicle body frame is increased for performance improvement, then traveling stability and turning operability are improved, but the fuel efficiency of the vehicle deteriorates
Solution Approach 1:
The motor case is merged with the vehicle body frame structure by integrating the motor accommodating portion, front fixing portion, upper-rear fixing portion, and lower-rear fixing portion into a unified assembly. This merging allows the motor case to serve dual purposes: housing the electric motor and providing structural support to enhance frame rigidity, thereby eliminating the need for separate reinforcement components and reducing overall vehicle weight.
Solution Approach 2:
The design changes the structural parameters of the motor case by extending fixing portions (front, upper-rear, and lower-rear) into the motor accommodating portion. These extended portions act as structural reinforcements that modify the rigidity distribution of the vehicle body frame, enhancing stability without requiring additional heavy materials, thus maintaining fuel efficiency while improving performance.
3Weight of moving object
If the weight of the vehicle body frame is reduced for fuel efficiency improvement, then fuel efficiency is improved, but traveling stability and turning operability deteriorate
Solution Approach 1:
The motor case is merged with the vehicle body frame structure by integrating the motor accommodating portion, front fixing portion, upper-rear fixing portion, and lower-rear fixing portion into a unified assembly. This merging allows the motor case to serve dual purposes: housing the electric motor and providing structural support to enhance frame rigidity, thereby eliminating the need for separate reinforcement components and reducing overall vehicle weight.
Solution Approach 2:
The motor case structure combines different functional requirements into a single composite-like design where the motor accommodating portion houses the motor while the extended fixing portions provide structural reinforcement. This integrated design achieves optimal strength-to-weight ratio by strategically placing material where it is most needed for both motor accommodation and structural support, rather than using uniform heavy reinforcement throughout the frame.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A straddle electric vehicle includes: a vehicle body frame including a motor case located between a front frame and a pivot frame; and an electric motor including a motor driving shaft that outputs driving force by which a rear wheel is driven. The motor case includes: a motor accommodating portion accommodating the electric motor; a front fixing portion fixed to the vehicle body frame; an upper-rear fixing portion fixed to the vehicle body frame; and a lower-rear fixing portion fixed to the vehicle body frame. In a side view of the vehicle, the motor driving shaft is located in a region surrounded by a virtual triangle defined by connecting the front fixing portion, the upper-rear fixing portion, and the lower-rear fixing portion.