Dual Lubrication Circuits for Automatic Transmission Start Clutch Cooling
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Solution Overview
Problem
Existing automatic transmissions face challenges in maintaining the durability of starting frictional engagement elements and lubricating oil due to excessive heat generation, leading to potential leakage and component deterioration.
Innovation Solution
A lubrication control apparatus with separate lubrication circuits for the starting frictional engagement element and other elements, controlled by a controller that adjusts flow rates based on temperature thresholds, using mechanical and electrical pumps to ensure adequate cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single lubrication circuit supplies lubricating oil to all frictional engagement elements, then the system is simple, but the starting frictional engagement element cannot receive adequate cooling under excessive heat load
Solution Approach 1:
The lubrication system is divided into two separate circuits: a first lubrication circuit dedicated to supplying lubricating oil to the starting frictional engagement element for cooling, and a second lubrication circuit for supplying lubricating oil to other lubricated portions. This segmentation allows independent control of oil flow rates to each circuit, enabling the controller to increase flow to the starting element while maintaining adequate flow through the oil cooler via the second circuit, thus resolving the temperature contradiction.
2Reliability
If the flow rate of lubricating oil is increased to cool the starting frictional engagement element, then durability of the starting element is improved, but fuel efficiency deteriorates due to increased energy consumption
Solution Approach 1:
The lubrication control apparatus dynamically adjusts the flow rate of lubricating oil supplied to the starting frictional engagement element based on real-time temperature conditions. The controller increases the flow rate only when the temperature of the starting element exceeds a predetermined threshold, and maintains normal flow rate when temperature is within acceptable ranges. This dynamic adaptation ensures durability is improved only when necessary, minimizing unnecessary energy consumption and maintaining fuel efficiency.
Solution Approach 2:
The system changes the operating parameter (flow rate of lubricating oil) based on the temperature condition of the starting frictional engagement element. When the temperature exceeds a threshold, the flow rate parameter is increased to enhance cooling; when temperature is normal, the flow rate returns to standard levels. This parameter adjustment ensures durability is improved only when necessary, minimizing unnecessary energy consumption.
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 approach effectively restrains temperature rises in both the starting frictional engagement element and lubricating oil, ensuring the durability of these components and maintaining fuel efficiency.
Implementation Method 1
a first lubrication circuit that supplies the lubricating oil to a starting frictional engagement element to be engaged when a vehicle starts
Implementation Method 2
the temperature of the lubricating oil is likely to rise while the durability of the starting frictional engagement element is ensured
Data Source
AI summary
A lubrication control apparatus for an automatic transmission includes a first lubrication circuit that supplies lubricating oil to a starting frictional engagement element to be engaged when a vehicle starts, a second lubrication circuit that supplies the lubricating oil to a lubricated portion other than the starting frictional engagement element, and a controller that performs control to increase a flow rate in the first lubrication circuit while limiting a flow rate in the second lubrication circuit when a temperature of the starting frictional engagement element is equal to or higher than a threshold temperature, and the controller changes the threshold temperature in accordance with the temperature of the lubricating oil.