Sealed compressor and refrigeration unit comprising sealed compressor
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Solution Overview
Problem
The existing sealed compressor bearing devices face issues with insufficient lubrication leading to increased noise and decreased efficiency due to uneven distribution of lubricating oil, and instability in the contact state between raceway grooves and balls, which can result in poor rolling performance.
Innovation Solution
The sealed compressor incorporates a thrust ball bearing with raceway grooves on the upper and lower races, and a limiting mechanism to prevent displacement, ensuring stable lubrication and smooth rolling of the balls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If raceway grooves are provided on the upper and lower races to stabilize lubrication, then lubrication stability is improved, but manufacturing precision requirements increase due to alignment sensitivity
Solution Approach 1:
The patent applies spherical curvature to the raceway grooves, designing them with a radius of curvature that matches the ball radius. This spherical geometry ensures that the grooves naturally guide and center the balls, maintaining alignment between upper and lower raceway grooves without requiring extremely tight manufacturing tolerances. The curved surfaces provide self-aligning characteristics that reduce sensitivity to manufacturing variations.
Solution Approach 2:
The patent optimizes specific parameters of the raceway grooves, including the radius of curvature (set to match the ball radius), groove depth (0.05-0.15 times the ball diameter), and groove width. By carefully controlling these parameters, the design achieves stable lubrication while accommodating reasonable manufacturing tolerances. The parameter optimization balances performance requirements with manufacturability.
2Ease of manufacture
If flat plate-shaped races are used, then manufacturing is simplified, but lubrication distribution becomes uneven causing noise and efficiency loss
Solution Approach 1:
The patent transitions from flat plate-shaped races to races with curved raceway grooves having a spherical cross-section. This curvature modification maintains the overall simplicity of the race structure while dramatically improving lubrication distribution. The spherical grooves naturally capture and distribute lubricating oil to the ball contact points, eliminating the uneven lubrication that causes noise and efficiency loss in flat designs.
Solution Approach 2:
The patent applies the local quality principle by modifying only the specific regions where balls contact the races, rather than changing the entire race structure. The raceway grooves are locally formed with spherical curvature at the contact zones, while the rest of the race maintains its simple structure. This localized modification achieves improved lubrication without significantly complicating manufacturing.
3Reliability
If raceway groove depth is increased to retain more lubricating oil, then lubrication stability improves, but ball displacement and rolling smoothness deteriorate
Solution Approach 1:
The patent optimizes the raceway groove depth parameter within a specific range (0.05-0.15 times the ball diameter). This parameter optimization ensures that the grooves are deep enough to retain sufficient lubricating oil for stable lubrication, but not so deep as to interfere with ball displacement and rolling motion. The optimized depth allows balls to move freely within the grooves while maintaining continuous lubrication contact.
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 stabilizes lubrication to the balls and races, reducing noise and enhancing efficiency by preventing sliding losses and maintaining smooth rotation.
Implementation Method 1
the lubricating oil stays in the raceway groove of the lower annular race 70, which enables the lubricating oil to be fed stably to the surfaces of the balls 66
Implementation Method 2
smooth rolling of the balls 66
Data Source
AI summary
A sealed compressor comprises a sealed container (101) which accommodates an electric component (105) and a compression component (106); wherein the compression component (106) includes a shaft (110) including a main shaft section (111) and an eccentric shaft section (112), a cylinder block (114), a piston (126), and a main bearing unit (120) mounted to the cylinder block (114) and supporting the main shaft section (112) such that the main shaft section (112) is rotatable, a thrust ball bearing (132) mounted to a thrust surface (130) of the main bearing unit (120); and the thrust ball bearing (132) includes a plurality of balls (134) held in a cage (133), an upper race (135) having main surfaces one of which is in contact with upper portions of the balls (134); and a lower race (136) having main surfaces one of which is in contact with lower portions of the balls (134) and; a restricting means for restricting a displacement of the upper race (135) with respect to the shaft (110).