Split Bearing Support Assembly for 5-Micron Compressor Alignment
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Solution Overview
Problem
Dynamic pressure gas bearings in centrifugal compressors face challenges due to low gas viscosity and high machining and assembling precision requirements, leading to low bearing capacity and instability.
Innovation Solution
A bearing supporting assembly with a through hole, fixing plate, radial bearing, and thrust bearings, where the fixing plate limits displacement and the bearing support's radial outline dimensions increase, ensuring precise machining and assembly, and a machining method that involves one-time location and clamping to achieve high precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dynamic pressure gas bearing is used in centrifugal compressor, then high precision and low friction loss are achieved, but bearing capacity is low due to low gas viscosity
Solution Approach 1:
The bearing support assembly is divided into multiple components: bearing support body, fixing plate, locating ring, and spigot. Each component performs a specific function to collectively achieve high precision positioning while supporting the bearing capacity requirements.
Solution Approach 2:
The bearing support assembly pre-establishes precise positioning through the locating ring engaging with the radial bearing outer wall and the spigot locating against the shell. This preliminary positioning ensures coaxiality and perpendicularity within 5 microns before the bearing operates, compensating for the low gas viscosity effect.
2Measurement precision
If bearing clearance is reduced to micron or tens of microns for high precision, then bearing performance is improved, but machining and assembling precision requirements become extremely high
Solution Approach 1:
The locating ring acts as an intermediary component between the fixing plate and the radial bearing. It engages with the outer wall of the radial bearing to pre-establish accurate positioning, serving as a mechanical mediator that ensures the required 5 micron coaxiality and perpendicularity without requiring extreme machining precision throughout the entire assembly process.
Solution Approach 2:
The patent replaces complex high-precision machining requirements with a mechanical locating system consisting of the locating ring and spigot. Instead of relying solely on precision machining to achieve 5 micron alignment, the mechanical locating features automatically establish the required precision through geometric constraints during assembly.
3Device complexity
If traditional bearing support structure is used, then structure is simple, but assembling precision and stability of bearing rotor system cannot be ensured within 5 microns
Solution Approach 1:
The bearing support assembly uses asymmetric positioning features: the spigot extends in a specific direction to locate against the shell, and the locating ring is positioned at a specific location on the fixing plate. These asymmetric features create unique geometric constraints that ensure precise positioning, achieving 5 micron assembling precision while maintaining relatively simple structure.
Solution Approach 2:
The locating ring is nested between the fixing plate and the radial bearing, creating a hierarchical positioning structure. The spigot is nested within the shell bore, and the radial bearing is nested within the bearing support. This nested arrangement allows multiple positioning functions to be achieved within a compact structure, ensuring precision without excessive complexity.
Data Source
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AI summary
The present disclosure relates to a bearing supporting assembly and a machining method thereof, and a centrifugal compressor. The bearing supporting assembly includes: bearing supports (52), provided with through holes (522) for mounting radial bearings (8); and a fixing plate (51), detachably mounted at one end of each of the bearing supports (52) along an axial direction, sides, away from the bearing supports (52), of the fixing plates (51) being configured to mount first thrust bearings (10'). The fixing plates and the bearing supports adopt a split structure, such that a perpendicularity of the through holes for mounting the radial bearings and end faces for mounting the fixing plates is ensured during machining, and the coaxiality of the through holes corresponding to the two bearing supports is ensured, thus ensuring the coaxiality of the two radial bearings. Therefore, the bearing supporting assembly is capable of improving the assembling precision of the bearing by ensuring the machining precision so as to improve the stability of a bearing rotor system, and is capable of increasing the qualification rate of part machining and reducing the machining cost.