Vehicle Accessory Power Management Assembly Speed Ratio Switching
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Solution Overview
Problem
Existing vehicle power systems provide accessory devices with rotary power at the same speed as the engine output shaft, leading to unnecessary high RPM power input when the engine is operating at high RPM, which can tax the engine and reduce efficiency.
Innovation Solution
A power transmitting device with a speed ratio switching mechanism, controlled by a controller, that adjusts the speed ratio between the input and output shafts based on engine speed and other parameters, allowing the accessory devices to receive reduced power during high RPM engine operation, thereby reducing torque burden on the engine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the accessory devices are directly driven by the engine output shaft at the same speed, then the accessory devices receive sufficient power, but the engine experiences unnecessary torque burden and reduced efficiency at high RPM
Solution Approach 1:
The patent applies a variable speed ratio mechanism that dynamically adjusts the transmission ratio between the engine output shaft and accessory devices based on engine operating conditions. The controller monitors engine parameters and changes the speed ratio to optimize power delivery, reducing the torque burden on the engine at high RPM while maintaining sufficient power to accessories when needed.
Solution Approach 2:
The system changes the speed ratio parameter between the input shaft and output shaft based on engine operating conditions. By varying this parameter, the system can decouple the direct 1:1 speed relationship, allowing accessories to receive appropriate power levels without forcing the engine to work at unnecessarily high torque levels during high RPM operation.
2Device complexity
If the speed ratio between input and output shafts is kept constant, then the transmission system is simple, but the system cannot adapt to varying engine operating conditions and accessory power requirements
Solution Approach 1:
The patent implements a dynamic speed ratio switching mechanism that transitions from a fixed constant ratio to a variable ratio system. The controller activates different clutch configurations based on engine parameters, enabling the transmission to adapt its characteristics to match varying operational requirements while maintaining manageable system complexity through controlled switching between predefined states.
Solution Approach 2:
The transmission system is designed to perform multiple functions through a single integrated mechanism that can operate in different modes. The same transmission assembly can provide both direct drive and reduced speed ratio operation, allowing it to serve different accessory power requirements without requiring separate transmission systems for different operating conditions.
Data Source
AI summary
A vehicle accessory power management assembly has a power device, an accessory device, a power transmitting device and a controller. The power transmitting device has an input part coupled to the power device, an output part coupled to the accessory device, and a speed ratio switching part switchable between a first operating state in which the input part and the output part rotate at a first speed ratio relative to one another and a second operating state in which the input part and the output part rotate at a second speed ratio relative to one another. The controller is configured to switch the speed ratio switching part between the first operating state and the second operating state in response determining whether the speed of output of the power device is above a pre-determined value or below a pre-determined value.