Scroll Fluid Machine Offset Parts Wear Reduction
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Solution Overview
Problem
Existing scroll fluid machines face issues with accelerated wear, increased driving force, and reduced durability due to the tilting of the orbiting scroll during operation, which leads to inefficiencies and performance deterioration.
Innovation Solution
The implementation of offset parts on the ventral and dorsal surfaces of the spiral wraps, reducing wrap thickness along the entire spiral direction, prevents contact between the tooth-tip parts of the spiral wraps, thereby alleviating wear and stress on the base parts and improving performance and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the orbiting scroll is driven to orbit around the stationary scroll by a crank shaft, then the spiral wraps are in tight contact to minimize leakage and improve sealing, but the tooth-tip parts experience accelerated wear, increased driving force, and higher stress on base parts
Solution Approach 1:
The patent applies local quality by providing offset parts at specific locations on the spiral wraps - specifically on the ventral surface and/or dorsal surface at predetermined positions in the spiral direction. This creates localized thickness variations that prevent tooth-tip contact while maintaining sealing performance in other critical areas.
Solution Approach 2:
The offset parts are designed in advance during manufacturing to preemptively prevent the tooth-tip contact problem. By reducing the wrap thickness at specific locations before operation begins, the patent eliminates the possibility of tooth-tip contact and associated wear, stress, and driving force issues.
2Duration of action of moving object
If offset parts are provided all along the height direction of the spiral wraps to prevent contact, then wear and stress are reduced, but the amount of gas leakage from offset parts increases and efficiency decreases
Solution Approach 1:
The patent precisely controls where offset parts are located within the height direction of the spiral wraps. By positioning them only in specific regions rather than along the entire height, the invention prevents tooth-tip contact while minimizing the surface area through which gas can leak, thus maintaining efficiency.
Solution Approach 2:
Instead of providing offset parts along the entire height direction (excessive action), the patent provides them only at predetermined positions and regions (partial action). This partial application is sufficient to prevent tooth-tip contact while avoiding the penalty of increased gas leakage that would result from full-height offset parts.
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
The offset parts effectively reduce wear, stress, and gas leakage, enhancing the performance and durability of the scroll fluid machine by preventing inter-scroll contact during orbital operation, while also simplifying processing and maintaining efficiency.
Implementation Method 1
the gap between a tooth-tip surface of each spiral wrap and a tooth-bottom surface of the other scroll is sealed to form sealed compression chambers; in this way, leakage of compressed gas from wrap gaps, tip gaps, etc. is minimized
Implementation Method 2
the orbiting scroll is driven to orbit while being tilted by a moment due to gas pressure acting in the height direction of the spiral wrap, which is vertically disposed on the opposite side of the end plate, and by a centrifugal force associated with the orbiting motion
Implementation Method 3
the orbiting scroll is driven to orbit while being tilted by a moment due to gas pressure acting in the height direction of the spiral wrap
Data Source
Figure 1
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AI summary
A scroll fluid machine that provides solutions to failures caused by an orbiting scroll tilting while being orbitally driven and that has improved performance and durability is provided. The scroll fluid machine includes a pair of scrolls, that is a stationary scroll and an orbiting scroll, including spiral wraps (31) vertically disposed on end plates (30), wherein the stationary scroll and the orbiting scroll are engaged by making the spiral wraps (31) oppose each other with the phases shifted, and offset parts (36, 37) are provided, in a direction that reduces the wrap thickness, on a ventral surface and a dorsal surface of a tooth-tip part of the spiral wrap (31) of at least one of the stationary scroll and the orbiting scroll, from the inner circumferential end to the outer circumferential end of the spiral wrap(31).