Friction Element Latch Device Using Screw Mechanism
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Solution Overview
Problem
Conventional friction element systems in automatic transmissions require continuous energy consumption to maintain engagement and need a separate power source for disengagement, leading to inefficiencies in energy use and complexity in control mechanisms.
Innovation Solution
A friction element latch device with a rotatable screw, movable piston, guide pins, and a guide groove system that uses a restriction device and elastic members to maintain engagement without continuous power input, allowing for simple control of engagement and disengagement through a single drive source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous power is supplied to maintain engagement of friction element, then engagement state is maintained reliably, but energy consumption increases
Solution Approach 1:
The screw mechanism is activated in advance to move the piston to the engaged position before power is cut off. Once the piston reaches the engaged position, the guide groove structure maintains the engagement state without requiring continuous power supply, thus achieving reliable engagement while reducing energy consumption.
Solution Approach 2:
The guide groove structure automatically maintains the piston in the engaged position through its geometric constraints without requiring external power. The system serves itself by using the structural design of the guide groove to hold the piston, eliminating the need for continuous energy input to maintain engagement.
2Ease of operation
If separate power source is used to release engagement state, then disengagement control is achieved, but device complexity increases
Solution Approach 1:
The same screw mechanism that moves the piston into engagement is also used to retract it for disengagement. By reversing the rotation direction of the single screw, both engagement and disengagement operations are achieved, eliminating the need for separate power sources and reducing control mechanism complexity.
Solution Approach 2:
The screw mechanism serves multiple functions: it both engages and disengages the friction element. This multi-functional design allows a single actuator to control the entire engagement cycle, simplifying the overall system architecture and reducing the number of required components.
3Use of energy by moving object
If guide groove restricts piston movement to maintain engagement, then energy consumption is reduced, but piston mobility is limited
Solution Approach 1:
The guide groove provides dynamic constraints that adapt to the operational phase. During engagement, the groove geometry restricts movement to maintain position and reduce energy consumption. During disengagement, the same groove allows controlled movement when the screw retracts the piston, thus balancing energy efficiency with necessary mobility.
Solution Approach 2:
The piston undergoes periodic movement between engaged and disengaged states. The guide groove restricts movement during the engaged phase to save energy, while allowing movement during the disengagement phase when actuated by the screw, creating a periodic cycle that alternates between constrained and mobile states.
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
Reduces energy consumption by eliminating the need for continuous power to maintain engagement, improves fuel efficiency, and simplifies the control of friction element engagement and disengagement, enhancing responsiveness and transmission efficiency.
Implementation Method 1
a screw arranged to be rotatable by receiving power from a driving source; a piston arranged to be movable by rotation of the screw
Implementation Method 2
a friction element such as a brake and a clutch, whose operation is selectively controlled at each shifting level
Implementation Method 3
The guide may further include a guide device for guiding the movement of the guide pin to move the piston in a direction in which the friction element is disengaged
Data Source
AI summary
A friction element latch device includes: a screw provided to be rotatable by receiving power from a driving source; a piston arranged to be movable by rotation of the screw; a guide arranged to selectively restrict movement of the piston; a guide pin protruding in a radial direction from an outer circumferential surface of the piston and guided by the guide; and a friction element arranged to be engaged as the piston moves.