Scroll Compressor Sub Bearing Arm Fixation via Shrink-Fit Harness
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Solution Overview
Problem
The existing scroll compressors face instability due to excessive load causing stress concentration and potential fatigue failure, especially with increased capacity and output, leading to disturbed operation.
Innovation Solution
A scroll compressor design featuring a tubular housing with a ring-shaped harness and multiple radial arms, where the arms are fixed to the harness using a fastening bolt and shim for alignment, ensuring stable fixation and centering, and a method involving shrink fitting to secure the harness to the housing, preventing arm and harness displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the capacity and output of the scroll compressor are increased, then the power and compression capability are improved, but the load on the main bearing and sub bearing increases excessively, causing stress concentration and potential fatigue failure
Solution Approach 1:
The sub bearing is divided into multiple arms (typically three) that are distributed around the rotary shaft. This segmentation distributes the load from the rotary shaft across multiple separate support points, reducing the stress concentration on any single bearing component and allowing the compressor to handle higher loads without fatigue failure.
2Device complexity
If the arms of the sub bearing are fixed to the housing using spot welding at one location, then the device complexity is reduced, but the arms may fall out due to vibration and excessive load
Solution Approach 1:
The harness is fitted into a specifically designed tubular structure within the housing that provides localized support and retention. This tubular structure creates a confined space that physically prevents the arms from falling out during vibration, while the harness provides additional constraint. This localized structural quality enhances reliability without significantly increasing overall device complexity.
3Reliability
If a harness is fitted onto the inner peripheral surface of the housing to secure the arms, then the reliability of arm fixation is improved, but the manufacturing precision and assembly difficulty increase
Solution Approach 1:
The harness is pre-formed and prepared before assembly, with its shape and dimensions optimized for fitting into the tubular structure. The tubular structure itself is pre-designed with specific dimensional tolerances that guide the harness into proper position. This preliminary preparation of components simplifies the final assembly process and reduces the precision requirements during actual assembly.
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 ensures long-term stable operation by distributing loads evenly and preventing fatigue failure, maintaining the compressor's operational stability under increased loads.
Implementation Method 1
a shrink fitting process that fixes the harness to the inner peripheral surface of the housing by shrink fitting
Data Source
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AI summary
A scroll compressor (100) includes an electric motor (3), a rotary shaft (4), a scroll compressor body, a main bearing, a sub bearing (9B) having a plurality of arms (79), a housing (1), a harness (40) having a ring shape and fitted onto an inner peripheral surface (1A) of the housing (1), and a fixed portion (B) in which the arms (79) of the sub bearing is fixed (9B) to the harness (40).