Hybrid Drive Arrangement with Planetary Gearsets for Reverse Driving
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Solution Overview
Problem
Hybrid vehicles lack a simple and cost-efficient solution for reverse driving that utilizes both combustion and electric engines, particularly in hybrid operation, and existing transmissions require significant constructive effort and are not highly efficient for trucks.
Innovation Solution
A drive arrangement comprising two planetary gearsets and three switching elements, allowing for independent operation of electric and combustion engines for forward, reverse, and purely electric driving modes, with a single actuator controlling the switching elements to minimize complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a transmission is added to hybrid vehicles to adapt speed and torque output, then the adaptability to driving resistance is improved, but the device complexity increases
Solution Approach 1:
The transmission is divided into two independent partial gears (first and second partial gears), each with its own input shaft and gear ratios. This segmentation allows the system to selectively engage different gear paths for different driving conditions, providing adaptability while keeping each partial gear relatively simple in structure.
Solution Approach 2:
The planetary gearset serves multiple functions: it can connect the electric engine to both input shafts, enable electrodynamic start-up, provide gear ratio changes, and facilitate switching between different drive modes (electric-only, combustion-only, hybrid). This multi-functionality reduces the need for separate components, thereby managing complexity.
2Adaptability or versatility
If a planetary gearset with multiple switching elements is used to enable reverse driving and hybrid operation, then the versatility of driving modes is improved, but the device complexity increases
Solution Approach 1:
The patent merges the reverse gear function and the hybrid drive control into the existing planetary gearset structure. By utilizing the inherent elements (sun gear, ring gear, carrier) and their multiple connection possibilities, the system achieves reverse driving capability without adding a separate reverse gear mechanism, thus limiting the increase in complexity.
Solution Approach 2:
The switching elements dynamically reconfigure the connections within the planetary gearset based on the desired driving mode. The system can switch between connecting the ring gear to the first or second input shaft, enabling flexible transition between forward driving, reverse driving, electric-only mode, and hybrid mode without mechanical reconfiguration.
3Ease of operation
If multiple switching elements are used to control different gear input shafts and planetary gearset connections, then the ease of operation for mode switching is improved, but the device complexity increases
Solution Approach 1:
The electric engine serves as both the actuator for the switching elements and the primary drive source. The control system electronically actuates the switching elements based on driving conditions, eliminating the need for complex mechanical shift mechanisms. The system self-regulates the switching based on sensor feedback and control algorithms.
Data Source
AI summary
A drive arrangement having combustion and electric engines and a transmission with input shafts (4, 5). The drive arrangement includes first and second planetary gearsets (PG1, PG2), each having a carrier, and sun and ring gears. One element of gearset (PG1) is rotationally fixed to shaft (5). Another element of gearset (PG1) is fixed to a housing. One element of gearset (PG2) is connected to the electric engine. Another element of gearset (PG2) is rotationally fixable to shaft (4). When a first switching element is engaged, a further element of gearset (PG2) is fixed to the housing. When a second switching element is engaged, the further element of gearset (PG2) is rotationally fixed to shaft (5), to which the element of gearset (PG1) is also rotationally fixed. When a third switching element is engaged, the further element of gearset (PG2) is rotationally fixed to a further element of gearset (PG1).