Rotatable Bicycle Drive Unit Housing for Frame Insertion
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Solution Overview
Problem
Existing bicycle drive unit mounting methods face difficulties in easily inserting the drive unit into the bicycle frame, particularly due to the configuration of male screws on the periphery, which can hinder the alignment and insertion process.
Innovation Solution
A method involving a housing with distinct portions, where the crankshaft is positioned on one portion and the propulsion assist motor on another, allowing the housing to be rotated and inserted into the frame in a manner that differs from the initial mounting position, facilitating easier alignment and insertion, and including steps such as moving the drive unit parallel to the crankshaft direction and inserting the crankshaft into a through hole for secure positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If male screws are provided on the periphery of the bicycle drive unit for mounting, then the drive unit can be securely fastened to the frame, but insertion of the drive unit into the frame becomes difficult
Solution Approach 1:
The housing is divided into a first portion (crankcase) and a second portion (motor housing) that can be rotated relative to each other. This segmentation allows the drive unit to be inserted in a different orientation than how it is ultimately mounted, resolving the contradiction between secure mounting and easy insertion.
Solution Approach 2:
The housing portions are designed to rotate relative to each other around the crankshaft axis. This dynamic capability enables the drive unit to transition from an insertion-friendly orientation to a mounting-friendly orientation, allowing easy insertion followed by secure fastening.
2Ease of manufacture
If the housing is configured for direct mounting with male screws, then mounting is straightforward, but the drive unit cannot be easily inserted into the frame
Solution Approach 1:
Dividing the housing into rotatable portions enables the drive unit to be manufactured with mounting features in fixed positions while allowing operational flexibility during installation through rotation before final mounting.
Solution Approach 2:
The drive unit is inserted into the frame in a preliminary orientation that facilitates easy insertion, then the housing portions are rotated to the correct mounting orientation before securing with male screws. This preliminary action resolves the contradiction between straightforward mounting and easy insertion.
3Device complexity
If the crankshaft extends in one direction, then the drive unit structure is simplified, but the drive unit cannot be mounted on various types of frames
Solution Approach 1:
The rotatable housing portions allow the drive unit to adapt to different frame types by changing its orientation during installation, while maintaining a simple crankshaft structure that extends in one direction. The rotation capability provides versatility without increasing structural complexity.
Solution Approach 2:
The rotatable housing design enables a single drive unit structure to be mounted on various types of frames with different opening orientations, providing universal compatibility while maintaining structural simplicity.
Data Source
AI summary
A method for mounting a bicycle drive unit to a frame of a bicycle, in which the bicycle drive unit includes a housing, a crankshaft and a propulsion assist motor. The housing has a first portion and a second portion. The crankshaft is provided to the first portion. The propulsion assist motor is provided to the second portion and includes a rotational axis extending in a direction intersecting a direction in which the crankshaft extends. The method includes a first step of arranging the first portion at a position for mounting the first portion on the frame, and a second step of rotating the housing about an axis parallel to a rotational axis of the crankshaft and inserting the second portion into an opening of the frame after the first step.