Eight-Speed Planetary Transmission Hydraulic Clutch Control
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Solution Overview
Problem
Current automatic transmissions for motor vehicles face inefficiencies in gear shifting and torque transmission, leading to parasitic losses and inadequate engine braking capabilities, particularly due to the limitations of traditional clutch and brake mechanisms.
Innovation Solution
A transmission design incorporating four simple planetary gear sets, a torque converter assembly with a one-way clutch and lock-up clutch, and hydraulically actuated friction clutches and brakes, which allows for precise control of gear shifts and torque distribution through the application of hydraulic pressure to achieve multiple speed ratios and efficient power transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional clutch and brake mechanisms are used in automatic transmissions, then the transmission can achieve gear shifting functionality, but parasitic losses increase and engine braking capabilities become inadequate
Solution Approach 1:
The patent applies dynamics by making the clutch and brake mechanisms controllable and adaptable through hydraulic pressure control. The system dynamically adjusts the engagement state of clutches and brakes based on operating conditions, enabling precise control over torque transmission and gear shifting while minimizing parasitic losses through optimized engagement timing and pressure control.
Solution Approach 2:
The patent employs hydraulics by using a hydraulic control system to actuate the clutches and brakes. Hydraulic pressure is used to engage and disengage the friction clutches and brakes, providing smooth torque transmission control and reducing mechanical impact during gear shifts. This hydraulic actuation system enables precise control while minimizing energy losses associated with traditional mechanical linkage mechanisms.
2Ease of operation
If traditional clutch mechanisms are used, then gear shifting can be achieved, but smoothness of gear shifting deteriorates
Solution Approach 1:
The patent uses hydraulic pressure control to achieve smooth gear shifting. The hydraulic system provides gradual and controlled engagement of clutches and brakes, eliminating sudden mechanical impacts. This hydraulic actuation allows for progressive torque transfer during gear transitions, ensuring smooth shifting while maintaining efficient torque transmission and minimizing energy losses.
Solution Approach 2:
The system dynamically controls the engagement process through hydraulic pressure modulation. By adjusting pressure levels and engagement timing, the system optimizes the smoothness of gear shifts while minimizing the duration of transitional states that would cause parasitic losses. The dynamic control enables adaptive adjustment based on vehicle operating conditions.
3Reliability
If traditional brake mechanisms are used, then speed control can be achieved, but engine braking capabilities become inadequate
Solution Approach 1:
The patent implements dynamic control of brake mechanisms through hydraulic pressure regulation. The system can selectively apply and modulate brake force based on driving conditions, enabling effective engine braking by controlling the release and engagement of brakes in coordination with gear selection. This dynamic control enhances reliability of speed control while minimizing energy losses through optimized brake application timing and force levels.
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 enables smooth gear shifting, minimizes parasitic losses, and provides effective engine braking, enhancing the overall efficiency and performance of the transmission system by allowing precise control over clutch and brake engagement.
Implementation Method 1
hydraulically actuated friction clutches and brakes, which allows for precise control of gear shifts and torque distribution through the application of hydraulic pressure
Implementation Method 2
hydraulically actuated friction clutches and brakes
Data Source
AI summary
A multiple speed power transmission comprising: four epicyclic gearing assemblies each having first, second, and third rotating elements with specified interconnections, an input shaft connected to one of the rotating elements, an output shaft, two rotating clutches releasably connecting the input shaft to rotating elements, and four brakes selectively holding rotating elements against rotation. Clutches and brakes are applied in combinations of two to produce eight forward ratios and one reverse ratio.