Hydraulic Control System for Automatic Transmission
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Solution Overview
Problem
Conventional hydraulic control systems in automatic transmissions face challenges in achieving improved efficiency, responsiveness, and smoothness, necessitating a more effective and cost-effective configuration.
Innovation Solution
The hydraulic control system incorporates an analog electronic transmission range selection (ETRS) subsystem with a pressure regulator, clutch actuator, manual valve assembly, latch valve assembly, park servo, and detent mechanism, along with solenoids and a stepper motor to selectively engage torque transmitting devices for various gear ratios and park conditions, enhancing fluid management and actuation precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional hydraulic control systems are used with traditional range selection mechanisms, then the system structure is simpler, but the efficiency, responsiveness, and smoothness of transmission operations deteriorate
Solution Approach 1:
The patent replaces traditional mechanical range selection mechanisms with an electronic control system. The electronic transmission range selection (ETRS) subsystem uses electronic signals to control solenoids, which in turn control hydraulic valves. This substitution of mechanical components with electronic-hydraulic components enables more precise and responsive control of torque transmitting devices, improving transmission operation efficiency while managing system complexity through integrated electronic control architecture.
Solution Approach 2:
The patent employs a sophisticated hydraulic control system where pressurized hydraulic fluid is distributed through multiple circuits to control various torque transmitting devices. The hydraulic system includes pressure regulators, flow control valves, and actuator circuits that work together to achieve smooth and efficient transmission operations. The hydraulic medium enables flexible and responsive actuation of clutches and brakes, directly contributing to improved productivity.
2Ease of operation
If traditional mechanical range selection is used, then the device complexity is lower, but the responsiveness and smoothness of transmission operations deteriorate
Solution Approach 1:
The patent replaces mechanical range selection linkages with an electronic control system that uses solenoids and hydraulic valves. The ETRS subsystem receives electronic range selection signals and translates them into hydraulic actuation commands. This electronic-hydraulic system responds more quickly and smoothly to range changes compared to mechanical systems, improving ease of operation through faster response times and smoother transitions between gear ranges.
Solution Approach 2:
The patent implements dynamic control through electronically controlled solenoids and hydraulic valves that can rapidly adjust fluid flow to torque transmitting devices. The system dynamically responds to driver inputs and transmission conditions, adjusting hydraulic pressure and flow rates in real-time. This dynamic control capability enhances transmission responsiveness while managing complexity through adaptive control algorithms and electronic sensor feedback.
3Adaptability or versatility
If more torque transmitting devices are added for multiple gear ratios, then the adaptability improves, but the device complexity and fluid management difficulty increase
Solution Approach 1:
The patent divides the transmission system into multiple independent torque transmitting devices, each controlled by its own hydraulic circuit and control valve. Forward clutches, reverse brakes, and range control mechanisms are segmented into separate controllable units. This segmentation allows each device to be independently actuated, enabling multiple gear ratios and adaptability while managing overall system complexity through modular control architecture.
Solution Approach 2:
The patent employs a universal hydraulic control system where a single pressurized fluid source serves multiple torque transmitting devices. The hydraulic system uses common pressure regulators and flow control mechanisms that can actuate different clutches and brakes as needed. This multi-functional approach provides adaptability for various gear ratios while reducing redundancy and managing system complexity through shared control resources.
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 enhances the efficiency, responsiveness, and smoothness of automatic transmission operations by precisely controlling torque transmitting devices and improving fluid management, leading to improved performance and cost-effectiveness.
Implementation Method 1
The ETRS subsystem includes an ETRS valve, a park servo, a park mechanism, a mode valve, and a plurality of solenoids
Implementation Method 2
a park servo in downstream fluid communication with the latch valve assembly and the manual valve assembly, and a park lock mechanism mechanically coupled to the park servo
Implementation Method 3
a detent mechanism connected to the manual valve, wherein the detent mechanism detents the manual valve into the Out of Park position
Data Source
AI summary
A hydraulic control system for a transmission includes a source of pressurized hydraulic fluid that communicates with an electronic transmission range selection (ETRS) subsystem. The ETRS subsystem includes an ETRS valve, a park mechanism, a mode valve, a latch valve assembly, and a plurality of solenoids. The ETRS subsystem is configured to provide desired operating conditions during a plurality of potential failure conditions.