Floating Annular Mass Bearing Dampens Centrifugal Whirling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional bearing devices with squeeze film dampers face challenges in achieving effective vibration attenuation due to oil film thickness limitations, leading to rigid oil films and potential centrifugal whirling, which can cause damage to the bearing retaining member or casing under large vibration loads.
Innovation Solution
Incorporating an annular mass member in a floating state between the outer race and the bearing retaining member, with first and second squeeze film damper parts, which counteracts centrifugal forces through inertial forces generated by an eccentric center of gravity, enhancing damping effects and preventing vibration transmission to the casing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the oil film thickness of the squeeze film is set to be large in advance to prevent the oil film from becoming rigid, then the vibration attenuation effect is improved, but the rotating shaft easily undergoes centrifugal whirling due to vibration
Solution Approach 1:
The patent introduces a floating annular mass member that can dynamically adjust its position and orientation in response to vibration conditions. The mass member is not fixed but floats on the squeeze film, allowing it to adaptively counterbalance centrifugal forces during whirling while maintaining appropriate oil film thickness for damping. This dynamic adjustment resolves the contradiction between maintaining thick oil film for damping and preventing centrifugal whirling.
Solution Approach 2:
The patent changes the operational parameters of the squeeze film system by introducing a floating mass member that modifies the oil film thickness distribution dynamically. The mass member creates a variable oil film thickness profile that is thicker in regions needing damping while thinner in regions needing stability, thus changing the parameter distribution to simultaneously achieve both vibration attenuation and centrifugal whirling prevention.
2Reliability
If conventional concentric springs are used to keep the oil film thickness constant, then the oil film thickness is maintained, but the force from centrifugal whirling is transmitted to the casing causing damage
Solution Approach 1:
The floating annular mass member acts as an intermediary between the outer race and the bearing retaining member. It absorbs and counterbalances the centrifugal forces through its own inertia, preventing these forces from being transmitted to the casing. The mass member mediates the interaction between the rotating shaft and the stationary casing, protecting the structure from damage while maintaining oil film thickness.
Solution Approach 2:
The annular mass member functions as a counterweight that offsets the centrifugal forces generated by the rotating shaft during centrifugal whirling. By positioning the mass member appropriately and allowing it to float on the squeeze film, it creates an opposing force that balances the centrifugal load, thereby protecting the bearing retaining member and casing from excessive forces.
3Volume of moving object
If the oil film thickness becomes too small under large vibration load, then the structure is more compact, but the oil film becomes rigid and vibration attenuation effect is lost
Solution Approach 1:
The floating annular mass member enables the oil film thickness to be dynamically optimized. Under normal conditions, the oil film can be thinner for compactness, but when vibration occurs, the mass member's movement and positioning automatically maintain sufficient oil film thickness in critical regions to preserve the vibration attenuation effect, thus resolving the contradiction between compactness and damping performance.
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 achieves a higher damping effect by synergistically combining the damping of the squeeze film damper parts with the inertial force of the annular mass member, effectively reducing vibration transmission and preventing damage to the bearing retaining member or inner casing.
Implementation Method 1
the inertial force acting on the annular mass member counteracts the centrifugal force acting on the rotating shaft, thus enabling a damping effect to be exhibited
Implementation Method 2
the centrifugal force acting on the rotating shaft
Implementation Method 3
a first squeeze film damper part formed between the outer periphery of the outer race and an inner periphery of the annular mass member, and a second squeeze film damper part formed between an outer periphery of the annular mass member and the inner periphery of the bearing retaining member
Data Source
AI summary
In a bearing device, a squeeze film damper includes an annular mass member disposed in a floating state between an outer periphery of an outer race and an inner periphery of a bearing retaining member, a first squeeze film damper part formed between the outer periphery of the outer race and an inner periphery of the annular mass member, and a second squeeze film damper part formed between an outer periphery of the annular mass member and the inner periphery of the bearing retaining member. Therefore, due to the floatingly supported annular mass member being eccentric with the opposite phase to a rotating shaft, which is eccentric and undergoes centrifugal whirling, an inertial force acting on the annular mass member counteracts the centrifugal force acting on the rotating shaft, thus enabling a damping effect to be exhibited.