Variable-Stiffness Hydraulic Powertrain Mount for Torque and Vibration
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Solution Overview
Problem
Vehicle powertrain mounts with a single stiffness struggle to effectively manage torque loads and vibrations, particularly during vehicle start-stop events, as they are either too stiff or inadequate in dissipating forces and vibrations.
Innovation Solution
A powertrain mount assembly featuring a main rubber element with an outer and inner armature, a hydraulic body, a membrane, and an electrically operated valve that adjusts stiffness by controlling fluid flow, allowing for relative movement and varying compliance based on valve position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a powertrain mount is designed with high stiffness to handle torque loads, then it can support high torque loads, but it cannot adequately damp vibrations and forces during normal operation
Solution Approach 1:
The patent implements a variable stiffness mount that dynamically adjusts its characteristics based on operating conditions. A valve assembly with a solenoid controls fluid flow between a first chamber and second chamber, allowing the mount to transition between a first state (higher stiffness for torque loads) and a second state (lower stiffness for vibration damping). This dynamic adjustment resolves the contradiction by making the stiffness property changeable rather than fixed.
Solution Approach 2:
The patent changes the physical parameters of the mount by controlling fluid pressure distribution. When the solenoid is de-energized, fluid flows to equalize pressure between chambers, creating a softer mount state. When energized, pressure differential is maintained for a stiffer state. This parameter change approach allows the same physical structure to exhibit different mechanical properties suitable for different operating conditions.
2Object-affected harmful factors
If a powertrain mount is designed with soft compliance to damp vibrations, then it can damp forces and vibrations, but it cannot adequately support high torque loads
Solution Approach 1:
The variable stiffness mount dynamically switches between compliant and rigid states. During normal operation with the solenoid de-energized, the mount maintains a softer compliance for vibration damping. When high torque loads are detected and the solenoid is energized, the mount transitions to a stiffer state to support the increased loads. This dynamic behavior resolves the contradiction between compliance and strength.
Solution Approach 2:
The mount alters its mechanical parameters through controlled fluid pressure changes. The solenoid-controlled valve assembly regulates fluid flow to adjust the pressure balance between the first and second chambers, thereby changing the overall stiffness parameter of the mount to match operational requirements - softer for vibration damping, stiffer for torque support.
3Device complexity
If a single stiffness mount is used for all operating conditions, then the design is simple, but it cannot optimize performance across different vehicle operations
Solution Approach 1:
The patent introduces a dynamic control system with a solenoid valve assembly that enables the mount to adapt to different operating conditions. The valve assembly includes a movable valve member controlled by a solenoid, which regulates fluid flow between chambers to adjust mount stiffness. This dynamic capability provides adaptability across various vehicle operations while maintaining a relatively compact and integrated structure.
Solution Approach 2:
The variable stiffness mount serves multiple functions within a single device: it provides vibration damping during normal operation, supports high torque loads during acceleration and load changes, and transitions between states based on operational needs. The integrated design combines the mounting function with active stiffness control, making the device versatile across different vehicle operating conditions.
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 provides a dynamically adjustable stiffness, enhancing vibration damping and noise reduction during engine restarts while maintaining sufficient stiffness for high torque loads, thereby improving vehicle comfort and performance across various operating conditions.
Implementation Method 1
a hydraulic body, a membrane and a valve. The MRE has an outer armature, an inner armature and an isolating element coupled to the outer armature and to the inner armature... the hydraulic body defines part of the fluid flow path, a fluid chamber that is communicated with the fluid flow path
Implementation Method 2
The membrane defines part of the control chamber and is arranged between the port and the fluid flow path... when the valve head is in the second position and fluid in the fluid flow path acts on the membrane, the membrane flexes relative to the fluid flow path
Implementation Method 3
The valve has a valve head movable relative to the port between a first position closing the port and a second position spaced from the port... when the valve head is in the first position air in the control chamber cannot exit the control chamber through the port
Implementation Method 4
the valve is electrically operated and the valve head is moved relative to the port in response to application of electricity to the valve
Data Source
AI summary
A powertrain component mount includes a housing, a main rubber element, a hydraulic body, a membrane and a valve. The main rubber element has an outer armature, an inner armature and an isolating element coupled to the armatures, the isolating element being formed of a material that is more flexible than the outer armature and the inner armature, wherein the main rubber element defines at least part of a fluid flow path. The hydraulic body supports the outer armature of the main rubber element, defines part of the fluid flow path, a fluid chamber, and part of a control chamber communicated with the fluid flow path. The hydraulic body has a port open to the control chamber. The membrane defines part of the control chamber and the valve has a valve head movable between a first position closing the port and a second position spaced from the port.