Cone Friction Clutch Release Control to Inhibit Drag Torque
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Solution Overview
Problem
Existing friction clutches face challenges in achieving a compact design with increased transmission torque capacity while preventing drag torque, especially under hydraulic control, as they tend to become stuck during release.
Innovation Solution
A friction clutch design featuring a cylindrical clutch drum, a hub, a piston, a pusher plate with a tapered surface, an end plate with a tapered surface, and a normally open type valve mechanism in a canceller chamber, which allows for efficient torque transmission through tapered surfaces and inhibits drag torque by controlling hydraulic oil flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the hydraulic pressure is increased to improve close contact between plates and friction plates, then transmission torque capacity is increased, but the friction clutch becomes larger and more complex
Solution Approach 1:
The patent employs conical surfaces with tapered geometry instead of traditional flat plate surfaces. The pusher plate and output cone feature complementary tapered surfaces that frictionally engage, converting axial hydraulic force into radial clamping force through the cone angle. This curved surface approach increases transmission torque capacity within a compact volume by leveraging mechanical advantage from the conical geometry.
Solution Approach 2:
The invention utilizes a hydraulic piston operating within a hydraulic chamber to generate the axial force required for frictional engagement. The hydraulic system provides controlled, high-magnitude force generation in a compact form, enabling the conical surfaces to achieve sufficient clamping pressure without increasing overall clutch size. The hydraulic chamber and piston mechanism efficiently convert fluid pressure into mechanical clamping force.
2Force
If the cone clutch is used to increase transmission torque capacity, then torque capacity is improved, but drag torque occurs when hydraulic pressure is released due to stuck engagement
Solution Approach 1:
The patent introduces a canceller component with a canceller chamber that acts as an intermediary mechanism to actively separate the conical friction surfaces during release. The canceller chamber receives hydraulic fluid that generates pressure to push the pusher plate away from the output cone, ensuring complete disengagement. This intermediary hydraulic separation mechanism prevents the conical surfaces from remaining stuck in partial engagement, thereby eliminating drag torque while maintaining compact dimensions.
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 enhances transmission torque capacity, maintains a compact size, and improves engagement and release responses by preventing drag torque through controlled hydraulic oil management.
Implementation Method 1
a third tapered surface (25) frictionally engaging the first tapered surface (21) and a fourth tapered surface (26) frictionally engaging the second tapered surface (23)
Implementation Method 2
when hydraulic oil is supplied to the canceller chamber (34), the valve of the valve mechanism (40) is closed... the piston and the pusher plate connected to the piston are pushed back by the hydraulic oil pressure
Implementation Method 3
a normally open type valve mechanism (40) which is arranged in the through hole (46)... when lubricating oil is supplied to the canceller chamber (34), a valve of the valve mechanism (40) is open, and when hydraulic oil is supplied to the canceller chamber (34), the valve of the valve mechanism (40) is closed
Data Source
Figure 1
Figure 2
AI summary
Provided is a friction clutch which is compact, has a large transmission torque capacity, and inhibits a drag torque from occurring. In the friction clutch 10, since the torque is transmitted between the clutch drum 12 and the hub 16 through each frictional engagement of the tapered surfaces on the pusher plate 20 and the output cone 24, and on the end plate 22 and the output cone 24, the transmission torque capacity of the friction clutch 10 can be increased and the friction clutch 10 can be comparatively compact. When the clutch is released, the hydraulic oil is supplied to the canceller chamber 34 to close the valve of the valve mechanism 40. Thus, the hydraulic oil is stored in the canceller chamber 34 and then the piston 18 and the pusher plate 20 connected to the piston 18 are pushed back by the hydraulic oil pressure. Therefore, drag torque can be inhibited.