Hybrid Drive Gear Shifting Using Generator Torque Relief
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Solution Overview
Problem
Existing hybrid drive systems face challenges in maintaining driving comfort and acoustic impressions during gear shifting, particularly when transitioning between combustion engine and electric motor power, as they often require friction clutches that increase complexity and cost.
Innovation Solution
A method where the first electric motor is temporarily connected to the combustion engine and operated in generator mode during shifting, allowing the combustion engine to continue operating and relieving the mechanical switching means, thereby eliminating the need for friction clutches and maintaining continuous torque and acoustic consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If friction clutches are used to enable power transmission during shifting operations, then shifting comfort is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and removes the friction clutch component from the transmission system. Instead of using friction clutches for power transmission during shifting, the invention employs a mechanical shifting means that directly engages and disengages gear elements without requiring friction-based slip control, thereby simplifying the device structure while maintaining shifting comfort
Solution Approach 2:
The patent replaces the friction clutch mechanism with a purely mechanical shifting system. The shifting operation is achieved through mechanical engagement of clutch elements and gear elements that can be directly coupled and decoupled without friction-based slip control, substituting the complex friction-based mechanical system with a simpler mechanical engagement system
2Duration of action of moving object
If friction clutches are used for shifting operations, then continuous power transmission is maintained, but weight and cost increase
Solution Approach 1:
The friction clutch components are extracted and removed from the transmission system. The patent uses a mechanical shifting means that engages and disengages gear elements directly, eliminating the need for friction clutch plates, springs, and associated heavy components, thereby reducing transmission weight while maintaining continuous power transmission capability
Solution Approach 2:
The control device prepares the mechanical shifting means in advance for the shifting operation. The clutch elements and gear elements are pre-positioned and pre-loaded so that when shifting is required, the mechanical engagement can occur rapidly without interruption to power transmission, maintaining continuous operation without the need for heavy friction clutch components
3Weight of moving object
If mechanical shifting means are used without friction clutches, then weight and cost are reduced, but shifting comfort and acoustic impression deteriorate
Solution Approach 1:
The patent employs dynamic control of the mechanical shifting means through a control device that actively manages the engagement and disengagement timing. The control device adjusts the shifting operation dynamically based on operating conditions, ensuring smooth transitions that maintain driving comfort and acoustic quality without requiring heavy friction clutch components
Solution Approach 2:
The control device acts as an intermediary between the driver's shifting request and the mechanical shifting means. It coordinates the timing and force application during shifting operations, mediating the interaction between the mechanical components to ensure smooth, comfortable shifts that mimic the behavior of friction clutch systems while using lighter mechanical components
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 approach enhances driving comfort by ensuring uninterrupted tractive force and torque, reduces emissions, and allows for cost-effective and efficient shifting without friction clutches, mimicking the behavior of a 'virtual double clutch' system.
Implementation Method 1
the first electric motor (1 EM-I) is operated in generator mode, whereby the combustion engine (1 VKM) is loaded and the first mechanical switching means (115) is relieved
Data Source
AI summary
The invention relates to a drive system, a control device, and a method for controlling a mechanical shifting operation in the drive system. The drive system has at least one first multi-gear transmission, having a first input shaft and a first mechanical shifting means. Torques coming from the first input shaft are transmitted to a drive system output shaft. The torques are produced by an internal combustion engine and/or at least one first electric motor. For the purpose of disengaging a gear of the multi-gear transmission, the first electric motor is connected to the internal combustion engine and operated in a generator operating mode at least at times during the shifting operation, whereby the internal combustion engine is loaded and the first mechanical shifting means is unloaded. The mechanical shifting means is thus free of load or torsion and can be easily disconnected/opened.