Three-Pass Torque Converter Layout Without a Forged Pilot Hub
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Solution Overview
Problem
Conventional torque converters with integrated clutches face challenges in cost, complexity, and clutch controllability due to their design, particularly the need for a large, complex forged pilot hub for fluid flow direction in three-pass designs.
Innovation Solution
A torque converter design with a simplified architecture featuring a damper assembly, seal plate, and three fluid passages that eliminate the need for a forged pilot hub by using a separate sealed apply chamber and non-crossed fluid flow, enhancing clutch controllability and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional three-pass torque converter design is used with integrated clutch and turbine, then fluid coupling function is achieved, but device complexity increases due to need for large forged pilot hub for fluid flow direction
Solution Approach 1:
The patent divides the fluid flow control function into separate components: the seal plate creates distinct sealed chambers (first apply chamber, second apply chamber, third chamber) that separate fluid flow paths. This segmentation eliminates the need for a single complex forged pilot hub while maintaining precise fluid direction control for clutch operation.
Solution Approach 2:
The seal plate acts as an intermediary component that directs fluid flow between chambers without requiring a large forged pilot hub. The seal plate with its specific openings and sealed chambers mediates the fluid flow paths, providing the necessary control function with reduced complexity.
2Ease of manufacture
If a simplified architecture without forged pilot hub is used, then costs and complexity are reduced, but clutch controllability may be compromised
Solution Approach 1:
By segmenting the apply pressure control into two separate sealed chambers (first and second apply chambers) with independent fluid supply paths, the system achieves precise clutch controllability without requiring an expensive forged pilot hub. Each chamber can be controlled independently for optimized clutch engagement.
Solution Approach 2:
The patent uses hydraulic fluid pressure control through multiple sealed chambers and flow paths to achieve precise clutch controllability. The hydraulic system with separate apply chambers provides the necessary control force without mechanical complexity of a forged pilot hub.
3Device complexity
If fluid flow paths are crossed in conventional design, then compact layout is achieved, but fluid circulation efficiency decreases
Solution Approach 1:
The seal plate serves as an intermediary that organizes fluid flow paths to prevent crossing. It creates distinct sealed chambers with dedicated supply and return paths, ensuring efficient non-crossed fluid circulation while maintaining compact overall layout through strategic placement of chambers and flow paths.
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 design achieves reduced costs and complexity while providing improved clutch controllability through precise pressure control and efficient fluid circulation, eliminating the need for a complex forged pilot hub and enhancing the overall efficiency of the torque converter.
Implementation Method 1
A damper assembly may be disposed between the front cover and the turbine shell. The damper assembly may comprise springs
Implementation Method 2
A damper assembly may be disposed between the front cover and the turbine shell
Implementation Method 3
the first chamber is supplied fluid from the first flow path such that the piston plate is displaced axially toward the turbine shell forcing the turbine piston against the impeller shell
Implementation Method 4
a turbine including a turbine shell axially movable to frictionally engage the impeller shell such that the turbine shell forms a turbine piston of a lock-up clutch
Data Source
AI summary
A torque converter comprises a front cover, an impeller including an impeller shell fixed to the front cover, and a turbine including a turbine shell axially movable to frictionally engage the impeller shell such that the turbine shell forms a turbine piston of a lock-up clutch. A damper assembly disposed between the front cover and the turbine shell comprises: springs; a flange connected to the turbine shell and drivingly engaged with the springs; and a spring retainer supporting the springs and connected to a turbine hub. A piston plate may be disposed between the spring retainer and front cover and configured to be axially displaceable to force the turbine piston against the impeller shell for engagement of the lock-up clutch. A seal plate may be fixed to the front cover and disposed between the front cover and the piston plate with the piston plate sealed to the seal plate.