Axial bearing, turbo compressor using same, and refrigeration cycle apparatus having same
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Solution Overview
Problem
Conventional hybrid axial bearings for turbo compressors using permanent magnets and electromagnets are costly, prone to component separation during restart or abnormal operations, and complicate assembly, leading to increased manufacturing costs and reduced reliability.
Innovation Solution
A hybrid axial bearing design incorporating a static pressure bearing and a dynamic pressure bearing, with orifices and foils to support the rotary shaft, allowing for stable support and reduced friction loss, and a refrigerant control system to adjust bearing operation based on load conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hybrid axial bearings using permanent magnets and electromagnets are used, then axial support function is provided, but manufacturing cost increases and reliability decreases due to component separation during restart or abnormal operations
Solution Approach 1:
The patent extracts the permanent magnet and electromagnet components from the hybrid axial bearing design and replaces them with a purely hydrodynamic bearing structure using bearing plates, foils, and refrigerant pressure. This eliminates the complexity and reliability issues associated with electromagnetic components while maintaining the axial support function through fluid pressure mechanisms.
Solution Approach 2:
The patent employs simpler, more durable bearing components (bearing plates, foils, and refrigerant-based pressure systems) that are less prone to failure and easier to manufacture than permanent magnets and electromagnets. These components can be readily replaced if needed and do not suffer from the component separation problems that plague electromagnetic bearing designs during abnormal operations.
2Loss of energy
If static pressure bearing is used to support rotary shaft, then friction loss is reduced during normal operation, but additional refrigerant supply system is required
Solution Approach 1:
The patent integrates the refrigerant supply system into the existing compressor refrigeration cycle, making the refrigerant serve dual purposes: both cooling/compression functions and bearing lubrication/pressure generation. The bearing plates and foils are designed to utilize the refrigerant pressure already present in the system, eliminating the need for separate lubrication systems and reducing overall device complexity.
3Stability of the object's composition
If both-end type turbo compressor configuration is used, then axial shaking is suppressed and thrust bearing size is reduced, but pipe complexity increases and compressor efficiency deteriorates due to pressure loss
Solution Approach 1:
The patent divides the compressor into separate first and second compression units with independent bearing systems for each end. This segmentation allows each bearing system to be optimized independently and simplifies the pipe connections between stages, as each end can operate with its own thrust management system rather than requiring complex cross-connecting piping.
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 design stabilizes rotary shaft support during normal and low-load operations, reduces manufacturing costs, and enhances reliability by minimizing friction and simplifying assembly, thereby improving compressor and refrigeration cycle apparatus efficiency.
Implementation Method 1
a bearing plate arranged on the bearing support member to face the side surface of the thrust runner in an axial direction, and including at least one orifice through which a refrigerant is sprayed toward the side surface of the thrust runner to support the rotary shaft in the axial direction
Implementation Method 2
a foil arranged on the bearing support member or the bearing plate to face the side surface of the thrust runner in the axial direction, and to support the rotary shaft in the axial direction by means of a dynamic pressure generated in rotation of the rotary shaft
Implementation Method 3
a first chamber formed in the housing to accommodate the driving motor, a second chamber formed in the housing to accommodate the axial bearing, a refrigerant flow path formed in the housing to guide the refrigerant from the first chamber to the second chamber, thereby cooling the axial bearing using the refrigerant that has cooled the driving motor
Data Source
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AI summary
Disclosed are an axial bearing, a turbo compressor using same, and a refrigeration cycle apparatus having same. The axial bearing, the turbo compressor using same, and the refrigeration cycle apparatus having same comprise an axial bearing comprising a bearing support member, a bearing plate, and a foil, wherein the bearing plate has at least one orifice for supporting a rotary shaft in the axial direction by spraying a fluid toward a thrust runner, and a foil, for supporting the rotary shaft in the axial direction by means of dynamic pressure generated when the rotary shaft rotates, may be provided on the outer or inner side of the orifice in the radial direction. Accordingly, friction loss between the thrust runner and the axial bearing at an early stage of an operation and/or during an overload operation can be suppressed, and at the same time, reliability and efficiency of the compressor and/or the refrigeration cycle apparatus, comprising the axial bearing can be increased during a normal operation and/or a low load operation.