Integrated Wet Clutch With One-Way Clutch for Drag Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric vehicles' electric machines produce higher rotational speeds than traditional engines, leading to increased speed differentials across clutches, which results in higher temperatures and wear, reducing clutch longevity.
Innovation Solution
A wet clutch system integrated with a one-way clutch that controls speed differentials across the clutch by adjusting torque transfer based on the electric motor's conditions, while maintaining desired lubrication through lubricating passages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If electric machines are used to generate torque for vehicle wheels, then higher rotational speeds and power output are achieved, but speed differential across the clutch increases leading to higher temperatures and wear
Solution Approach 1:
The clutch system dynamically adjusts the coupling state between the electric motor and transmission based on operating conditions. The control system monitors speed differential and temperature, then selectively engages or disengages the clutch to prevent excessive heat generation while maintaining power transmission capability when conditions are favorable.
Solution Approach 2:
The clutch acts as an intermediary element between the high-speed electric motor and the transmission system. By controlling the engagement and disengagement of this intermediate component, the system can decouple the motor from the transmission during high-speed differential conditions, preventing direct transmission of harmful thermal effects while maintaining the power pathway when safe.
2Power
If electric machines operate at higher rotational speeds, then greater power is produced, but friction and drag energy generate substantially higher temperatures in the clutch pack
Solution Approach 1:
The system dynamically manages energy losses by adjusting clutch engagement based on real-time monitoring of speed differential and temperature conditions. When the electric motor operates at high speeds creating excessive friction and drag, the clutch is disengaged to eliminate these energy losses, allowing the motor to maintain high power output without wasting energy as heat in the clutch pack.
3Force
If speed differential across the clutch is increased, then torque transfer capability is improved, but wear increases and longevity is reduced
Solution Approach 1:
The clutch system employs dynamic control to optimize the balance between torque transfer capability and component longevity. The control algorithm continuously assesses operating conditions and adjusts clutch engagement accordingly, allowing high torque transfer when speed differential is manageable, but disengaging the clutch when speed differential would cause excessive wear, thereby extending the service life of the clutch while maintaining required torque transmission performance.
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 integration of a one-way clutch within the wet clutch system effectively manages speed differentials, reducing drag losses and temperature differentials, thereby enhancing clutch operation and extending its longevity.
Implementation Method 1
a one-way clutch integrated into the wet clutch between the gear and the hub
Implementation Method 2
The wet-clutch may further include various lubricating passages in a shaft on which the wet clutch is arranged. The lubricating passages may promote lubricant flow to various portions of the wet clutch.
Implementation Method 3
The increased speed differential may produce substantially higher temperatures from friction and drag energy to a clutch pack compared to a lower speed differential.
Data Source
AI summary
Systems and a method for a clutch assembly are provided. In one example, a wet clutch for an electric motor includes a plurality of friction plates connected to a clutch hub; a plurality of separator plates connected to a drum and interleaved with the plurality of friction plates, a gear coupled to the electric motor; and a one-way clutch integrated into the wet clutch so as to be positioned between the gear and the clutch hub to allow free rotation in a predetermined direction while the wet clutch is hydraulically actuated and the friction plates and the separator plates rotate at the same speed thus avoiding drag losses.