Power-Split Planetary Gearset With Dual Inputs for More Operating Ranges
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Solution Overview
Problem
Existing electromechanical power-split hybrid systems have limitations in the number of operating ranges and efficiency, with complex and costly designs that result in high transmission losses and reduced reliability.
Innovation Solution
The use of a planetary gearset with double input and double output, interconnected through dual planet gears and a double-flow gearbox, allowing for increased operating ranges and reduced losses by optimizing the connection of motor-generators and internal combustion engine inputs to achieve lower fuel consumption and CO2 emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple planetary gears, clutches and brakes are used to achieve greater number of speed stages, then the number of operating ranges increases, but the device complexity and manufacturing cost increase
Solution Approach 1:
The single planetary gearset is designed with dual inputs (mechanical from internal combustion engine, electrical from motor-generator) and dual outputs, allowing it to perform multiple functions: power splitting, speed multiplication, and enabling multiple operating ranges (direct drive, gear drive, electric drive) without requiring multiple separate planetary gearsets. This multi-functionality resolves the contradiction by achieving adaptability through a universal component rather than through system multiplication.
2Adaptability or versatility
If multiple clutches and brakes are used to increase operating ranges, then the number of speed stages increases, but transmission losses increase due to friction and inertia
Solution Approach 1:
The invention extracts and eliminates the need for multiple friction clutches and brakes by using a single planetary gearset with controlled input/output connections. The motor-generator serves as an alternative to mechanical friction-based switching, reducing transmission losses by removing the harmful friction elements while maintaining the capability for multiple operating ranges through electronic control of the motor-generator.
3Ease of operation
If hydrostatic units are used to change the sense of rotation, then the output speed reversal is achieved, but the efficiency decreases due to considerable control range requirements
Solution Approach 1:
The invention replaces the hydrostatic control system with a direct mechanical connection through the planetary gearset, where the sense of rotation is changed by controlling the motor-generator's rotation direction. This substitution eliminates the efficiency losses associated with hydrostatic control while maintaining the ease of operation for output speed reversal through electronic control of the electric motor.
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 increases the number of operating ranges, reduces fuel consumption, and minimizes losses by simplifying the system design and reducing the number of components, making it more efficient and cost-effective compared to existing hybrid solutions.
Implementation Method 1
a planetary gearset with dual planet gears and has four input/output members which are divided into two pairs, each dual planet gear being connected to all said four input/output members
Implementation Method 2
an electric drive branch with a first motor-generator block including a first motor-generator, and a second motor-generator block including a second motor-generator
Data Source
AI summary
An electromechanical power-split system and a method of operating thereof is provided, with a mechanical drive branch including an internal combustion engine (3), and with an electric drive branch including a first motor-generator block (59) including a first motor-generator (1) and a second motor-generator block (60) including a second motor-generator (2), the first motor-generator (1) is connectable to the internal combustion engine (3) and to the second motor-generator (2). The system includes a planetary gearset (4) with dual planet gears (46) and four input/output members for altering the flow ratio of the mechanical and electric drive branch. Each dual planet gear (46) is connected to the four input/output members, which are a first pair of input/output members formed by a first sun gear (41) and a ring gear (44), and a second pair of input/output members formed by a second sun gear (43) and a planet carrier (45).