Horizontal Rotary Compressor Frame Surface Roughness
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Solution Overview
Problem
In horizontal rotary compressors, accurately controlling the oil level between the compression mechanism and electric motor chambers while preventing refrigerant leakage and energy loss is challenging due to the differential pressure between these spaces.
Innovation Solution
A rotary compressor design featuring a frame that supports the compression mechanism, includes passages for refrigerant and lubricating oil, and uses a main bearing with a cylinder contact surface and frame contact surface of varying roughness to manage oil levels and refrigerant flow, along with specific passage configurations and a differential pressure regulating valve to control differential pressure and oil levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the frame and cylinder contact surface is made smooth to reduce friction, then the bearing contact surface requires higher precision, but manufacturing complexity increases
Solution Approach 1:
The invention applies different surface roughness characteristics to different regions of the cylinder end face. The frame contact surface (outer peripheral region) is made with larger surface roughness to enhance lubrication and reduce friction, while the bearing contact surface (inner peripheral region) maintains appropriate precision for bearing function. This local differentiation resolves the contradiction by optimizing each region for its specific function rather than requiring uniform high precision across the entire surface.
2Reliability
If the oil level in the first space is made higher than in the second space to ensure lubrication, then the compression mechanism is reliably lubricated, but the electric motor may suffer energy loss from oil contact
Solution Approach 1:
The invention uses the frame as an intermediary structure that creates a differential pressure zone between the first space (compression mechanism) and second space (electric motor). The frame, with its specific surface roughness and positioning, maintains a higher oil level in the first space for reliable lubrication while preventing excessive oil from reaching the second space, thus protecting the electric motor from energy loss due to oil contact.
3Reliability
If the frame contact surface and cylinder contact surface are made to match precisely, then refrigerant leakage is minimized, but manufacturing precision requirements increase
Solution Approach 1:
The invention optimizes the outer peripheral region of the cylinder end face (frame contact surface) with specific surface roughness characteristics that enhance sealing performance through improved lubrication film formation. This local optimization allows for effective sealing without requiring extremely high dimensional precision across the entire contact surface, as the rougher outer region compensates for minor dimensional variations while maintaining reliable sealing.
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 design ensures reliable lubrication, minimizes refrigerant leakage, and accurately controls oil levels, enhancing the compressor's reliability and performance by maintaining appropriate differential pressures and oil levels within the chambers.
Implementation Method 1
a frame contact-surface that is disposed radially outside of the cylinder than the bearing contact-surface to contact the frame. The bearing contact-surface is closer to the electric motor than the frame contact-surface. Surface roughness of the frame contact-surface is rougher than surface roughness of the bearing contact-surface.
Data Source
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AI summary
To Provide a highly reliable horizontal rotary compressor that includes a compression mechanism supported in a housing via a frame, lubricating oil supply to the compressor is reliably continued, and an energy loss in an electric motor can be prevented; and a refrigeration cycle device provided with the compressor. This rotary compressor is provided with a sealed housing (11), an electric motor (12), a compression mechanism (13), a frame (23) which divides the inside of the sealed housing into an electric-motor chamber (21) and a compression-mechanism chamber (22), and a plurality of bolts (25) that fasten the compression mechanism to the frame. The compression mechanism includes a main bearing (16) fasten to the end surface (31a) of a cylinder (31), which is close to the electric motor, and closing a cylinder chamber (29). The bearing contact-surface (51) of the end surface of the cylinder, the bearing contact-surface (51) being in contact with the main bearing, is located closer to the electric motor than a frame contact-surface (52) which is positioned further outside in the radial direction of the cylinder than the bearing contact-surface and which is in contact with the frame. The surface roughness of the frame contact-surface is greater than the surface roughness of the bearing contact-surface. The contact-surface (23a) of the frame is a single continuous flat surface located above the bolt (25a) located at the lowest position among the plurality of bolts.