E-Bike Frame Layout for Straight Battery Removal and Rigidity
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Solution Overview
Problem
Existing electric bicycles with central motors face issues of decreased rigidity and unsightly battery accommodation due to limited space below the frame, leading to asymmetric or bulky frame constructions.
Innovation Solution
The drive battery is accommodated in the down tube with a straight removal path, and the drive unit is positioned above the frame section, allowing for a U-shaped frame geometry that maintains rigidity and aesthetic appeal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a battery and motor are mounted in the rear wheel hub, then the center of gravity shifts backward and assembly is simplified, but riding stability deteriorates due to unbalanced weight distribution
Solution Approach 1:
The battery is divided into two separate battery packs that are distributed to different wheel hubs. This segmentation allows the weight to be balanced across the vehicle while keeping each battery pack compact and easy to assemble into the hub structure.
Solution Approach 2:
The first and second battery packs are positioned asymmetrically in the front and rear wheel hubs respectively, but their combined weight distribution creates a balanced center of gravity. This asymmetric placement simplifies assembly while achieving weight balance through strategic positioning.
2Ease of manufacture
If the battery is built in the form of a hub motor, then assembly is simplified, but the battery cannot be easily detached for charging
Solution Approach 1:
The battery system is segmented into two independent battery packs that can be separately installed and removed from the wheel hubs. This allows the battery to be detached for charging while maintaining the simplified hub-integrated structure during normal operation.
Solution Approach 2:
The battery packs are designed with dynamic installation and removal capabilities, allowing them to be easily attached to and detached from the wheel hubs. This enables flexible operation where the battery can be quickly removed for charging and reinstalled when needed.
3Stability of the object's composition
If the battery is mounted in the vehicle body, then weight distribution is balanced, but assembly becomes complicated
Solution Approach 1:
Instead of mounting one large battery in the vehicle body, the battery is segmented into two smaller packs that are distributed to the wheel hubs. This segmentation simplifies assembly while achieving balanced weight distribution through strategic placement at the wheels.
Solution Approach 2:
The battery mounting location is shifted from the vertical dimension (vehicle body) to the horizontal dimension (wheel hubs). This dimensional change allows weight distribution to be achieved through lateral placement rather than central mounting, simplifying the assembly structure.
4Duration of action of moving object
If a large-capacity battery is used to extend driving distance, then driving range increases, but the battery becomes a safety hazard due to increased risk
Solution Approach 1:
The large-capacity battery is divided into two smaller battery packs with distributed capacity. This segmentation reduces the energy concentration in each pack, lowering the safety risk while maintaining the total driving range through combined capacity of both packs.
Solution Approach 2:
Each battery pack is designed with localized safety features and thermal management tailored to its specific position and capacity. This local optimization reduces safety risks by addressing the specific conditions of each battery pack rather than treating them as a single large system.
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
This configuration enhances frame rigidity with slim profiles, simplifies assembly, and improves the appearance of the bicycle by optimizing the use of available space and reducing mechanical stress on the frame.
Implementation Method 1
a generator (22) that generates electric power by using a driven force from the driven wheel
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
An electric bicycle with a central motor has a frame (100) comprising a down tube (120), a seat tube (110) and a frame section (150) linking the down tube (120) and the seat tube (110). The frame (100) features an opening delimited inter alia by the down tube (120), the seat tube (110) and the frame section (150). It further comprises a drive unit (200) 5 including the motor and a bottom bracket for accommodating a crank. The drive unit (200) is accommodated in the opening of the frame (100), adjacent to the frame section (150). A drive battery is accommodated in the down tube (120), and the down tube (120) comprises an access opening at an end of the down tube (120), arranged in such a way that the drive battery is removable from the down tube (120) along a straight removal path of the battery.