Wet Double Clutch Piston Stop Structure to Prevent Escape
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing double wet clutches in motor vehicle transmissions face issues with piston escape during abnormal operations, leading to potential failures and increased complexity and cost due to the need for additional safety mechanisms like circlips.
Innovation Solution
A double wet clutch design with a control system featuring an abutment surface that limits the axial displacement of the force transmission member, positioned at a specific axial distance from the force transmission member, preventing piston escape and reducing the overall stroke of the piston, thus enhancing reliability without additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an independent stop element like a circlip is mounted in a groove to limit piston movement, then piston escape is prevented, but device complexity and manufacturing cost increase
Solution Approach 1:
The invention merges the stop function into the existing guide bearing housing structure. The axial extension bearing surface of the guide bearing housing directly serves as the stop surface, eliminating the need for separate stop elements like circlips. This integration maintains piston containment while reducing device complexity.
Solution Approach 2:
The guide bearing housing performs multiple functions: it guides the piston axially, supports the rotating thrust bearing, and provides the stop surface to limit piston travel. By making the housing multi-functional, the invention eliminates dedicated stop components while maintaining reliability.
2Manufacturing precision
If the piston stroke is made long to accommodate wear and deformation, then component tolerance is improved, but the risk of piston ejection increases
Solution Approach 1:
The invention incorporates a safety margin by positioning the stop surface at a distance from the fully engaged position of the multi-disc assembly. This preliminary limitation of piston travel prevents the piston from reaching positions where wear and deformation could cause ejection, while still accommodating normal operational tolerances.
Solution Approach 2:
The axial extension bearing surface acts as a pre-positioned safety barrier that limits piston travel before abnormal conditions can develop. This beforehand constraint prevents piston ejection even when wear and deformation occur during operation.
3Reliability
If additional safety components are added to prevent piston escape, then reliability improves, but manufacturing cost increases
Solution Approach 1:
The stop function is merged into the guide bearing housing that already exists in the system. By utilizing the axial extension bearing surface of this existing component as the stop surface, the invention eliminates the need for additional safety components, thereby reducing manufacturing cost while maintaining reliability.
Solution Approach 2:
The guide bearing housing serves itself by providing both guidance and stopping functions. The same component that guides piston movement also provides the stop surface, eliminating the need for separate safety components and reducing overall manufacturing cost.
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 ensures the reliability and safety of the double wet clutch by limiting piston displacement and preventing escape, even when the multi-disc assembly is worn, without the need for additional safety features like circlips, resulting in a more compact and cost-effective design.
Implementation Method 1
a hydraulic control system comprising a housing, intended to be fixed to the gearbox, having two concentric annular chambers and two annular pistons that move axially within each of the two annular chambers
Implementation Method 2
Each piston carries a rotating thrust bearing that bears against a power transmission element cooperating with one or the other of the two clutches
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a wet double clutch (1) comprising first and second clutches (E1, E2), of the multi-disk type, the first clutch (E1) being located radially outside the second clutch (E2), each of the first and second clutches (E1, E2) comprising: - an input-side disk carrier (8, 9) attached to an input hub (6) which is common to the first and second clutch (E1, E2) and designed to be rotatably coupled to the crankshaft; - a multi-disk assembly (10, 11) connected to the input-side disk carrier (8, 9); - a force transmission member (25, 38) which is movable in translation along the axis O so as to actuate the multi-disk assembly (10, 11) between a disengaged position and an engaged position of the clutch (E1, E2); said wet double clutch (1) comprising a stop surface (60) capable of limiting the axial movement of the force transmission member (25) of the first clutch (E1) in the direction of the multi-disk assembly (10).