Torque Converter Axial Downsizing via Turbine Nesting
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Solution Overview
Problem
The existing torque converter design faces challenges in axial downsizing due to the positional arrangement of the lockup damper and lockup clutch, which increases the axial dimension of the entire converter to ensure fluid circulation space.
Innovation Solution
The torque converter design features a turbine with an outer peripheral portion bulging toward the engine and an inner peripheral portion on the engine side, with a concaved intermediate portion between them, allowing the lockup damper to be positioned axially overlapping with the torus, and the lockup clutch to be directly coupled to the casing, thereby reducing the axial dimension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the lockup damper and lockup clutch are disposed on the engine side of the torus to ensure proper positioning, then the shock absorption and direct coupling functions are achieved, but the axial dimension of the torque converter increases
Solution Approach 1:
The patent repositions the lockup damper from the traditional engine-side location to a location that axially overlaps with the torus. This spatial reconfiguration allows the damper to be integrated within the existing axial envelope of the fluid circulation path, eliminating the need for additional axial space while maintaining the shock absorption function during lockup clutch engagement.
Solution Approach 2:
The lockup damper is positioned within the axial space already occupied by the torus structure. By nesting the damper's axial position within the existing fluid working section boundaries, the design avoids adding external axial dimensions while still providing the necessary shock absorption capability.
2Reliability
If the axial dimension of the torus is increased to ensure fluid circulation space, then the fluid circulation is maintained, but the overall axial dimension of the torque converter increases
Solution Approach 1:
The turbine shell employs differential shaping with bulging portions and concaved portions that locally optimize the fluid circulation path. The bulging portions toward the engine side and concaved portions on the opposite side create efficient fluid flow channels without requiring uniform axial expansion, maintaining fluid circulation while controlling overall axial dimension.
Solution Approach 2:
The turbine shell incorporates curved surfaces including bulging portions and concaved portions that optimize fluid circulation paths. These curved geometries enable efficient fluid flow guidance within a compact axial envelope, maintaining circulation performance without increasing axial dimension.
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 configuration effectively reduces the axial dimension of the torque converter while maintaining efficient fluid circulation and shock absorption during lockup clutch engagement, enhancing engine fuel economy and transmission efficiency.
Implementation Method 1
a lockup damper having an elastic member adapted to absorb shock during engagement of the lockup clutch
Implementation Method 2
a turbine disposed opposed to the pump from a side of the engine with respect to the pump and adapted to be rotationally driven by the pump through fluid
Data Source
AI summary
Disclosed is a torque converter (1) which comprises: a casing (10) coupled to an output shaft of an engine; a torus (T) defined by a pump (20), a turbine (30) and a stator (40) each disposed within the casing (10); a lockup clutch (60) adapted to directly couple the turbine (30) and the casing (10); and a lockup damper (70) adapted to absorb shock during engagement of the lockup clutch (60). The turbine (30) has an outer peripheral portion (31a) bulging toward the engine to define a part of the torus (T), an inner peripheral portion (31c) located on the side of the engine with respect to a one-way clutch (50) supporting the stator (40), and an intermediate portion (31b) formed to be concaved toward a side opposite to the engine, in a radial position between the outer peripheral portion (31a) and the inner peripheral portion (31c). A part (75) of the lockup damper (70) is disposed on the side of the engine with respect to the intermediate portion (31b) and in a position axially overlapping with the torus (T). This makes it possible to allow a torque converter to be axially downsized.