E-Bike Planetary Drive Assembly for Smooth Gear Shifting
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Solution Overview
Problem
Existing drive arrangements for vehicles, such as bicycles and electric bicycles, face inefficiencies due to the size of manual transmission structures and jerky transitions caused by torque and power flow reversals when using direct gears.
Innovation Solution
An operating method utilizing a planetary gearbox that eliminates torque and power flow reversals by controlling the locking and releasing of sun gears and planetary stages, allowing for variable translation without direct gears, resulting in simplified torque sensing and a more compact structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If direct gears are used in the transmission device, then the structure is simpler, but torque and power flow reversals occur causing jerky transitions
Solution Approach 1:
The patent removes direct gears from the transmission device, extracting the problematic component that causes torque and power flow reversals. The transmission now exclusively uses planetary gear stages, eliminating the source of jerky transitions while maintaining gear ratio variability through controlled locking and releasing of sun gears and planetary stages.
Solution Approach 2:
The patent implements dynamic control of the planetary gear system by selectively locking and releasing sun gears and planetary stages during operation. This dynamic adjustment allows smooth transition between different gear ratios without the jerky transitions associated with direct gears, as the power flow remains continuous and controlled throughout the transmission process.
2Ease of operation
If planetary gears are used to eliminate torque flow reversal, then operation smoothness improves, but the device complexity increases
Solution Approach 1:
The planetary gear stages serve multiple functions simultaneously: they provide gear ratio variation, eliminate torque flow reversal, and enable smooth operation. By designing the transmission so that planetary stages perform all these functions, the patent avoids needing separate mechanisms for each function, thereby managing complexity while achieving multiple benefits.
Solution Approach 2:
The planetary gear system is designed to self-regulate power flow direction through its inherent structure. The controlled locking and releasing of sun gears and planetary stages allows the system to automatically prevent torque flow reversal without requiring external intervention or complex control mechanisms, making the system self-sufficient in maintaining smooth operation.
3Adaptability or versatility
If multiple sun gears and planetary stages are controlled, then gear ratio variability increases, but the control mechanism becomes more complex
Solution Approach 1:
The transmission device is divided into multiple independent planetary gear stages, each with its own sun gear that can be controlled separately. This segmentation allows for precise control of gear ratios by selectively locking or releasing individual sun gears, providing high adaptability while keeping each control unit relatively simple and modular.
Data Source
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AI summary
The present invention relates to an operating method for a drive arrangement (80) for a vehicle (1), an electric bicycle, e-bike or pedelec, which can be driven by muscle power and/or, in particular, additionally by motor power. The drive arrangement (80) is configured with a crankshaft (15) rotatable about an axis of rotation (Y) for receiving a first torque, in particular one generated by muscle power, and with a transmission device (20) which is configured to transmit the first torque from the crankshaft (15) to an output element (4) that can be coupled to a drive wheel (9-2) of the vehicle (1) and to a variable transmission by means of a multi-stage planetary gear (21), which is configured to be switchable, in particular automatically.In this operating procedure, the respective gear ratio of the planetary gear set (21) is set by selecting or changing gears and by controlled locking and/or unlocking of the respective sun gears (55, 56) and/or the planetary stages (57, 58) corresponding to the sun gears (55, 56). For each gear ratio and for each gear of the drive arrangement (80), at least one of the sun gears (55, 56) and/or at least one of the planetary stages (57, 58) corresponding to the sun gears (55, 56) is always locked.