Supercharger Drive with Variator Ratio Control
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Solution Overview
Problem
Existing drive arrangements for superchargers in internal combustion engines face inefficiencies due to fixed gear ratios, leading to wasted energy and potential torque reduction when accelerating, as they struggle to optimize supercharger speed and torque delivery in response to varying engine demands.
Innovation Solution
A drive arrangement using a continuously-variable transmission with a toroidal variator, controlled by a system that adjusts the variator ratio to match engine conditions, ensuring the supercharger operates at optimal speed while limiting torque changes to prevent transient torque reductions, thereby optimizing energy delivery and maintaining cost, weight, and complexity efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a fixed ratio gear train is used to drive the supercharger, then the supercharger operates at a constant multiple of crankshaft speed, but energy is wasted at high engine speed and torque delivery is insufficient at low engine speed
Solution Approach 1:
The patent applies a continuously variable transmission (CVT) with a variator mechanism that dynamically adjusts the gear ratio between the crankshaft and supercharger. This allows the drive ratio to change continuously based on engine operating conditions, optimizing torque delivery at low speeds while preventing energy waste at high speeds, thereby resolving the contradiction between productivity and energy loss.
2Speed
If a variable ratio drive is immediately swept from low to high ratio during sudden acceleration, then the supercharger accelerates quickly, but a substantial part of engine torque is absorbed to accelerate the supercharger and is unavailable to accelerate the vehicle
Solution Approach 1:
The control system performs preliminary action by pre-planning the variator ratio sweep trajectory before sudden acceleration occurs. When acceleration is detected, the system gradually sweeps the ratio rather than immediately, preparing the supercharger acceleration in advance while managing torque demands to ensure adequate power remains available for vehicle acceleration.
Solution Approach 2:
The control system continuously monitors engine torque, supercharger speed, and vehicle acceleration demands, using feedback to dynamically adjust the variator ratio sweep rate. This closed-loop control ensures that the supercharger accelerates quickly when needed while preventing excessive torque absorption that would reduce power available for vehicle acceleration.
3Reliability
If a torque-controlled variator system is used to control maximum inertial torque to the supercharger, then the control problem is solved, but the system becomes costly and heavy due to required actuators and hydraulic control apparatus
Solution Approach 1:
The patent replaces the complex hydraulic control apparatus and high-power actuators with a more compact and cost-effective actuator design. The new system uses a simplified mechanical or electric actuator that directly controls the variator ratio without requiring elaborate hydraulic systems, thereby maintaining control reliability while reducing device complexity and cost.
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 solution allows for efficient and controlled supercharger operation, minimizing energy waste and maintaining torque delivery during sudden accelerations, while reducing costs and complexity by using a low-power actuated variator with a simple control system.
Implementation Method 1
a variator operatively connected between the input and the output of the transmission, which variator has an output that is driven at an operating ratio from an input
Data Source
AI summary
A supercharging arrangement for an internal combustion engine is disclosed. The supercharging arrangement comprises a supercharger having a rotational drive input, and a transmission having a rotational drive input to receive drive from an internal combustion engine, and a rotational drive output connected to the input of the supercharger. The transmission includes a variator operatively connected between the input and the output of the transmission, which variator has an output that is driven at an operating ratio from an input. There is a control system that operates to cause an engine to deliver an amount of torque that is indicated by the state of an input to the control system. The control system is further operative to set the operating ratio of the variator.