Vane Rotary Compressor Bearing Back Pressure Pockets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing vane rotary compressors face issues with mechanical efficiency, stability of the rotation shaft, increased frictional losses, and abrasion due to unstable behavior and pressure fluctuations, especially when using high-pressure refrigerants like R32, R410a, and CO2, leading to reduced performance under high-pressure, low-temperature, and high-speed conditions.
Innovation Solution
The design enhances mechanical efficiency by forming a continuous bearing surface and differentiating back pressure applied to vanes, using a vane rotary compressor with a cylinder, main and sub bearings, and back pressure pockets with varying pressures, and communication flow paths to stabilize the rotation shaft and prevent foreign material accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the first pocket is opened toward the rotation shaft to form a discontinued surface, then oil can be introduced into the first pocket through the gap between the rotation shaft and the bearing, but the overall support force of the bearing is lowered and the rotation shaft behavior becomes unstable
Solution Approach 1:
The bearing surface is segmented into multiple sections: a first bearing surface facing the first pocket, a second bearing surface facing the second pocket, and a third bearing surface facing the rotation shaft. This segmentation allows each surface to serve its specific function independently, with the first and second bearing surfaces providing support while the third bearing surface allows oil introduction without compromising overall stability.
Solution Approach 2:
Different regions of the bearing are given different properties: the first and second pockets are closed to form continuous bearing surfaces for support, while the third pocket is opened to allow oil introduction. This local differentiation enables the bearing to simultaneously provide stable support and facilitate lubrication.
2Ease of operation
If the first pocket is opened between the bearing and the rotation shaft, then oil introduction is enabled, but pressure fluctuations increase and vane behavior becomes unstable
Solution Approach 1:
The back pressure system is segmented into multiple independent pockets (first, second, and third pockets) with different functions. The first and second pockets maintain stable back pressure for vane support, while the third pocket is opened to allow oil introduction without affecting the pressure stability of the other pockets.
3Productivity
If the number of vanes is increased to handle high-pressure refrigerants, then compression capability is improved, but the bearing surface area is reduced and frictional loss increases
Solution Approach 1:
The bearing structure is segmented to provide multiple bearing surfaces (first, second, and third bearing surfaces) that collectively provide sufficient support area even when the number of vanes increases. This segmentation ensures that the bearing can handle both the increased load from more vanes and the requirement for adequate lubrication.
4Reliability
If a continuous bearing surface is formed, then rotation shaft stability is improved, but oil introduction capability is reduced
Solution Approach 1:
The bearing surface is divided into multiple segments with different configurations. The first and second bearing surfaces are continuous to provide stable support, while the third bearing surface is opened to enable oil introduction. This segmentation allows both continuous support and oil introduction to coexist.
Solution Approach 2:
Different local regions of the bearing are designed with different properties: closed regions (first and second pockets) for stable support and an opened region (third pocket) for oil introduction. This local quality differentiation resolves the contradiction between continuity and accessibility.
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 increases radial supporting force, stabilizes vane behavior, reduces collision noise and leakage, and prevents abrasion, enhancing the reliability and efficiency of the compressor even under challenging conditions.
Implementation Method 1
bearing protrusion portions formed on an inner circumferential side of the back pressure pockets facing the rotation shaft and forming radial bearing surfaces with respect to an outer circumferential surface of the rotation shaft
Implementation Method 2
the communication flow path is formed to be smaller than a cross-sectional area of an inner circumferential side of the back pressure pocket facing the rotation shaft
Implementation Method 3
back pressure chambers each formed in another end of the vane slots so as to communicate with the back pressure pocket
Data Source
AI summary
A vane rotary compressor has a cylinder. A main bearing and a sub bearing are coupled to the cylinder forming a compression space. The main and sub bearing each have a back pressure pocket on a surface facing the cylinder. The main bearing and the sub bearing radially support a rotation shaft. A roller coupled to the shaft is disposed within the compression space. The roller has circumferentially spaced vane slots, each vane slot extending from an open end on an outer circumferential surface of the roller to a back pressure chamber disposed within the roller at an opposite end of each vane slot. A plurality of vanes slide within the vane slots and divide the compression space into compression chambers. At least one of the back pressure chambers in the vane slots fluidly communicates with at least one of the back pressure pockets in the main and sub bearings.