Rotary Compressor Axial Bearing Support Oil Film Pressure
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Solution Overview
Problem
Existing rotary compressors experience friction loss and wear due to axial displacement of the roller caused by magnetism in the drive motor, leading to reduced performance and reliability.
Innovation Solution
The rotary compressor incorporates axial support parts extending from the outer circumferential surface of back pressure pockets on the main and sub bearings, which increase oil film pressure to stabilize the roller and reduce friction loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gap between the roller and the main bearing or sub bearing is narrowed to suppress axial displacement, then friction loss and wear are reduced, but it becomes difficult to form an oil film
Solution Approach 1:
The bearing sliding surface is segmented into multiple functional zones: a first axial support part with a first gap for oil film formation, and a second axial support part with a second gap (smaller than the first) for suppressing axial displacement. This segmentation allows each zone to optimize for its specific function without compromising the other.
Solution Approach 2:
Different regions of the bearing sliding surface are given different gap characteristics: the first axial support part has a larger gap suitable for oil film formation, while the second axial support part has a smaller gap for axial displacement suppression. This local differentiation resolves the contradiction by applying appropriate gap sizes to appropriate locations.
2Object-generated harmful factors
If a large axial gap is generated to facilitate oil film formation, then oil film pressure is sufficient, but leakage between compression chambers occurs through the axial gap
Solution Approach 1:
The bearing sliding surface is divided into functional zones with different gap sizes: the first axial support part has a larger gap for oil film formation, while the second axial support part has a smaller gap that prevents leakage between compression chambers. This segmentation allows simultaneous optimization of lubrication and sealing functions.
Solution Approach 2:
Different gap characteristics are applied to different locations: larger gaps in regions where oil film formation is critical, and smaller gaps in regions where leakage prevention is critical. This local quality differentiation resolves the contradiction between oil film formation and compression efficiency.
3Adaptability or versatility
If the roller is allowed to move axially due to magnetism, then the drive motor characteristics are maintained, but friction loss and wear increase between the roller and bearings
Solution Approach 1:
The bearing design accommodates the dynamic axial movement characteristics of the roller caused by motor magnetism. The second axial support part with its smaller gap is specifically designed to limit excessive axial displacement while allowing the roller to maintain its natural movement characteristics, thereby reducing friction and wear.
4Productivity
If the axial gap is reduced to prevent leakage, then compression efficiency is improved, but friction loss increases due to difficulty in forming an oil film
Solution Approach 1:
The bearing sliding surface is segmented into zones with different gap sizes: larger gaps in the first axial support part for oil film formation, and smaller gaps in the second axial support part for leakage prevention. This segmentation allows simultaneous optimization of compression efficiency and friction reduction.
Solution Approach 2:
Different gap characteristics are applied locally: larger gaps where oil film formation is needed to reduce friction, and smaller gaps where leakage prevention is needed to maintain compression efficiency. This resolves the contradiction between compression efficiency and friction loss.
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 solution effectively suppresses friction loss and wear between the roller and the bearings, improving compressor performance and reliability by stabilizing the axial support force and maintaining smooth oil supply.
Implementation Method 1
form an oil film pressure generator between a roller and a main bearing or/and a sub bearing facing the roller
Data Source
AI summary
In a rotary compressor, at least any one of a main bearing or a sub-bearing may have at least one axial-direction support portion that extends from an outer circumferential surface of a back pressure pocket and is formed to have a predetermined depth. The compressor may increase an oil film pressure that supports a roller in an axial direction thereof to stably support the roller including a rotational shaft in the axial direction, thereby effectively suppressing or preventing friction loss and abrasion between the roller and the main bearing facing the roller and between the roller and the sub-bearing.