Variable Speed Supercharger with Planetary Friction Drive
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Solution Overview
Problem
Conventional superchargers have a fixed gear ratio, resulting in insufficient boost ratios at low engine speeds, which limits engine torque and efficiency across the entire engine speed range.
Innovation Solution
An electro-mechanical variable speed supercharger combines a supercharger and an alternator with a three-branch planetary friction drive, allowing for fully controllable boost-on-demand operation through three operating modes: boosting, neutral, and charging, utilizing an electric machine to adjust the impeller-to-pulley speed ratio for optimal engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed gear ratio is used in the supercharger, then the structure is simple, but the boost ratio is insufficient at low engine speeds
Solution Approach 1:
The patent applies a variable speed mechanism that dynamically adjusts the impeller speed relative to engine speed. The system transitions from a fixed gear ratio to a dynamic transmission system that can vary the speed ratio, allowing the impeller to maintain optimal speed across different engine operating conditions, particularly improving low-speed boost performance.
Solution Approach 2:
The transmission system is designed to perform multiple functions: it provides both fixed and variable speed ratios, and can operate in different modes (boosting mode, neutral mode, charging mode) depending on engine conditions. This multi-functionality allows a single system to address various performance requirements across the entire engine speed range.
2Power
If the impeller speed is increased to improve low-speed torque, then the engine power output increases, but the energy consumption increases
Solution Approach 1:
The system dynamically adjusts impeller speed based on real-time engine conditions. At low engine speeds, the variable speed mechanism increases impeller speed to maintain adequate boost pressure and torque. At high engine speeds, the system reduces the speed multiplication to minimize energy consumption, creating an optimal balance between performance and efficiency across the operating range.
Solution Approach 2:
The transmission ratio is changed as a variable parameter rather than being fixed. The system continuously adjusts the speed ratio parameter based on engine speed and load conditions, allowing optimal energy transfer at each operating point. This parameter variation enables the system to achieve high torque when needed while minimizing energy losses during normal operation.
3Adaptability or versatility
If a variable speed supercharger is implemented, then the boost ratio is optimized across engine speeds, but the device complexity increases
Solution Approach 1:
The transmission system is designed to perform multiple functions within a single integrated structure. It provides both fixed and variable speed capabilities, and can operate in different modes (boosting, neutral, charging) depending on engine conditions. This multi-functionality allows the system to achieve high adaptability without proportionally increasing complexity.
Solution Approach 2:
The patent introduces a variable speed mechanism as an intermediary between the engine and impeller. This intermediary component enables smooth transition between different operating modes and provides the necessary speed adaptation without requiring complete redesign of the supercharger system. The variable speed mechanism acts as a mediator that reconciles the conflicting requirements of simplicity and adaptability.
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
The solution provides consistent engine torque and power across the entire engine speed range, enhancing fuel efficiency and reducing weight, while also enabling intelligent electric power generation to maintain battery state of charge.
Implementation Method 1
a three-branch, high-ratio planetary friction drive comprising an outer ring, a sun shaft, and three sets of planetary clusters mounted in a carrier or multiple carriers
Data Source
AI summary
A supercharger for boosting intake manifold pressure in an internal combustion engine and producing electrical energy comprises an input shaft (3), a electric machine (50) including a stator (51) and a rotor (53), a compressor (70) including an impeller (71), and a planetary transmission (30) located between the input shaft (3) and the rotor (53) of the electric machine (50) and the impeller (71) of the compressor (70), all such that the input shaft 3 can drive both the impeller (71) and the rotor (53), or the rotor (53) and input shaft (3) can drive the impeller (71). The planetary transmission (30) includes an outer ring (31) operatively coupled to the input shaft (3), a sun member (39) operatively coupled to the impeller (71), planetary clusters (38) located between the outer ring (31) and sun member (39), and a carrier (37) operatively coupled to the planet clusters (38) and the rotor (53). Each planetary cluster (38) comprises an inner roller (35) and an outer roller (33).