Position-Based Damping Isolator for BAS Torque Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional isolators fail to effectively manage torsional vibrations and torque transmission in vehicles equipped with Belt-Assisted Start (BAS) drive systems, where an electric motor is used to start the engine, leading to inefficiencies and potential damage.
Innovation Solution
An isolator design featuring a shaft adapter, rotary drive member, and a position-based damping structure that transfers torque via frictional damping force between the rotary drive member and shaft adapter, with a selected amount of relative movement that prevents excessive spring compression and ensures efficient torque transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional isolator is used in a BAS drive system, then the isolator can reduce torsional vibrations, but the isolator cannot effectively manage torque transmission during engine starting and may cause excessive spring compression or failure
Solution Approach 1:
The isolator employs a movable damping member that can dynamically change its position along the shaft adapter between a retracted position and an extended position. This dynamic adjustment allows the isolator to adapt to different operating conditions: during normal operation the damping member is retracted to minimize friction, while during BAS events it extends to provide frictional damping and protect the spring arrangement from excessive compression
Solution Approach 2:
The isolator changes the friction parameter between the damping member and shaft adapter based on operational needs. By controlling the engagement of the damping member with the shaft adapter, the system can vary the frictional force from minimal (during normal operation) to significant (during BAS events), thereby protecting the spring arrangement from damage while maintaining adaptability to the BAS drive system
2Object-generated harmful factors
If the damping structure engages at large relative movement, then it can provide frictional damping, but it allows excessive spring compression that may damage the spring arrangement
Solution Approach 1:
The damping member is positioned to engage with the shaft adapter before the spring arrangement reaches its maximum compression limit. This preliminary engagement provides frictional damping that prevents the spring arrangement from experiencing excessive compression forces that could cause damage, while still allowing sufficient relative movement to effectively dampen torsional vibrations
3Object-generated harmful factors
If the isolator allows relative movement between rotary drive member and shaft adapter, then it can dampen vibrations, but it reduces torque transmission efficiency
Solution Approach 1:
The isolator dynamically adjusts the frictional engagement between the damping member and shaft adapter based on operational conditions. During normal operation, the damping member is retracted to minimize friction and maximize torque transmission efficiency. During BAS events or when torsional vibrations are present, the damping member extends to provide frictional damping, thereby reducing energy loss only when necessary
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 isolator effectively isolates torsional vibrations and manages torque transmission in BAS systems, preventing spring damage and maintaining efficiency during engine starts and operation, while reducing kinetic impacts and extending the isolator's longevity.
Implementation Method 1
a first isolation spring arrangement that is positioned to transfer torque between the shaft adapter and the rotary drive member
Implementation Method 2
a position-based damping structure that is positioned to transfer torque via a frictional damping force between the rotary drive member and the shaft adapter
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In an aspect, an isolator is provided for isolating a device driven by an engine via an endless drive member. The isolator includes a shaft adapter that is connectable with a shaft of the device, a rotary drive member that is engageable with the endless drive member, a first isolation spring arrangement that is positioned to transfer torque between the shaft adapter and the rotary drive member, and a position-based damping structure. The damping structure is positioned to transfer torque via a frictional damping force between the rotary drive member and the shaft adapter at a selected amount of relative movement therebetween. The selected amount of relative movement is selected to be less than a maximum permitted amount of flexure of the first isolation spring arrangement.