Scroll Compressor Arm Fixing with Differentiated Pin Holding Forces
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Solution Overview
Problem
Existing scroll compressors face challenges in stabilizing the arm structure due to uneven press-fitting loads from welding pins, which can lead to damage and reduced durability.
Innovation Solution
The design incorporates a fixing portion with distinct first and second holes, where the first pin is press-fitted into a hole centered over the arm's minimum sectional area, and the second pin into a hole outside this area, with the first pin experiencing a stronger holding force to distribute loads more evenly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If multiple welding pins are press-fitted into the fixing portion to secure the arm to the casing, then the connection strength is improved, but the press-fitting loads become uneven causing arm structure instability
Solution Approach 1:
The patent applies local quality by creating different hole configurations at specific locations within the fixing portion. The first hole is positioned to overlap the minimum sectional area portion of the arm when viewed along the first direction, while the second hole is positioned outside this minimum sectional area portion when viewed along the second direction. This localized differentiation in hole positioning ensures that pins experience different holding forces appropriate to their locations, resolving the contradiction between connection strength and structural stability.
2Duration of action of stationary object
If the arm structure is strengthened to withstand press-fitting loads, then the durability is improved, but the compressor size increases
Solution Approach 1:
Instead of uniformly strengthening the entire arm structure, the patent uses local quality by strategically positioning holes at specific locations (one overlapping the minimum sectional area portion and another outside it). This localized approach allows the arm to withstand press-fitting loads effectively while maintaining a compact overall structure, thus improving durability without increasing compressor size.
Solution Approach 2:
The patent applies preliminary action by pre-positioning the holes in optimal locations before the press-fitting process. The first hole is预先 positioned to overlap the minimum sectional area portion and the second hole is预先 positioned outside this area, so that when pins are press-fitted, the loads are automatically distributed in a way that stabilizes the arm structure without requiring additional strengthening measures.
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 enhances the stability of the arm structure, reducing the risk of damage from press-fitting loads and ensuring stable support of the lower bearing, while maintaining the compressor's compact size and strength.
Implementation Method 1
The first pin is press-fitted into the first hole and fixed to the casing by welding
Implementation Method 2
fixed to the casing by welding
Implementation Method 3
The second pin is press-fitted into the second hole and fixed to the casing by welding
Implementation Method 4
fixed to the casing by welding
Data Source
AI summary
A scroll compressor includes a crankshaft, a bearing rotatably supporting the crankshaft, a casing accommodating the crankshaft and the bearing, an arm supporting the bearing, a fixing portion connected to an end of the arm and fixed to the casing, and first and second pins. The first and second pins are press fitted into first and second holes and fixed to the casing by welding. The first hole is formed in the fixing portion and has a first center disposed at a position overlapping a minimum sectional area portion of the arm. The second hole is formed in the fixing portion and has a second center disposed at a position outside the minimum sectional area portion of the arm. A first force with which the first pin is held by the fixing portion is larger than a second force with which the second pin is held by the fixing portion.