Compliant Gear Assembly Attenuates Torque Spikes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gear systems in internal combustion engines experience excessive noise and premature wear due to impulsive loads, which are not effectively addressed by traditional methods such as increasing mass or incorporating compliance, as these solutions lead to increased weight and complexity.
Innovation Solution
A compliant gear assembly with a hub subassembly and a gear ring that moves between two stop positions, utilizing a compliance mechanism to bias the gear ring toward a first stop position and allowing it to translate perpendicular to the hub axis in response to torque, maintaining meshing of adjacent gears and reducing noise and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional gear systems are used with rigid connections, then structural simplicity is maintained, but excessive noise and premature wear occur due to impulsive loads
Solution Approach 1:
The patent applies dynamics by making the gear ring movable relative to the hub, allowing it to translate perpendicular to the hub axis in response to applied torques. This dynamic capability enables the gear assembly to accommodate impulsive loads from cylinder firing and fuel injection, preventing gear tooth separation and reducing noise and wear while maintaining reasonable structural complexity
Solution Approach 2:
The patent changes the positional parameter of the gear ring relative to the hub, allowing translation between first and second stop positions. This parameter change enables the system to adapt to varying torque conditions, maintaining gear meshing under impulsive loads and reducing harmful effects without excessive structural complexity
2Stability of the object's composition
If gear mass is increased to reduce susceptibility to torque disturbances, then gear train stability improves, but system weight increases
Solution Approach 1:
Instead of increasing mass for stability, the patent uses a movable gear ring that can dynamically respond to torque impulses by translating relative to the hub. This dynamic adaptation provides stability under varying loads without increasing the overall weight of the gear assembly
Solution Approach 2:
The patent changes the operational parameters of the gear assembly by allowing the gear ring to translate between stop positions in response to torque conditions. This parameter adjustment provides stability under impulsive loads without requiring increased mass
3Object-affected harmful factors
If compliance mechanisms are incorporated to reduce impulsive load effects, then noise and wear are reduced, but device complexity increases
Solution Approach 1:
The patent implements a compliance mechanism through the movable gear ring that translates relative to the hub under torque loads. This dynamic compliance accommodates impulsive loads from cylinder firing and fuel injection, reducing noise and wear while maintaining a relatively simple structural implementation with defined stop positions
4Adaptability or versatility
If gear teeth are allowed to separate and collide during operation, then compliance with torque impulses is achieved, but excessive noise and energy loss occur
Solution Approach 1:
The patent uses the dynamic translation of the gear ring between first and second stop positions to adapt to torque impulses. This controlled movement maintains gear tooth contact during impulsive events, preventing separation and collision that cause noise and energy loss while achieving necessary compliance
Solution Approach 2:
The patent changes the positional parameter of the gear ring relative to the hub, allowing translation that accommodates torque impulses without gear tooth separation. This parameter adjustment provides adaptability to varying loads while preventing the harmful effects of gear rattle and energy waste
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 compliant gear assembly effectively reduces noise and wear by allowing gears to maintain meshing during operation, attenuating impulsive loads, and smoothing torque transmission, thereby extending the lifespan of gear components and improving the operational environment.
Implementation Method 1
a compliance mechanism coupled between the first hub component and the second hub component and biasing the second hub component toward the first stop position
Data Source
AI summary
A compliant gear assembly for a gear train of an internal combustion engine includes a hub subassembly having a first hub component and a second hub component. The first hub component defines a first axis, and the compliant gear assembly includes a gear ring rotatable relative to the hub subassembly and defining a gear ring axis of rotation. The second hub component is movable relative to the first hub component in a direction normal to the first axis between a first stop position at which the gear ring axis of rotation is co-linear with the first axis and a second stop position at which the gear ring axis of rotation is parallel to but not co-linear with the first axis. A compliance mechanism is coupled between the first hub component and the second hub component and biases the second hub component toward the first stop position. Translating the second hub component relative to the first hub component in a direction normal to the first axis attenuates torque spikes induced for example via fuel injector actuation and/or cylinder firing in an engine gear train employing the compliant gear assembly.