Scroll Compressor Piston Ratchet for Capacity Modulation
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Solution Overview
Problem
Current compressors in climate-control systems face inefficiencies in capacity modulation, leading to suboptimal performance in providing cooling and heating effects, as they lack effective mechanisms to switch between full and reduced capacity modes efficiently.
Innovation Solution
The compressor design incorporates a piston and piston-retention member system that allows selective fluid communication with different pressure sources, enabling axial biasing and rotation control to switch between full and reduced capacity modes by engaging and disengaging the orbiting and non-orbiting scrolls, utilizing a ratchet mechanism and spring biasing to secure the piston in place.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a compressor uses fixed capacity operation, then the structure is simple, but the energy efficiency deteriorates due to inability to modulate capacity
Solution Approach 1:
The compressor employs a movable piston that can be positioned in different axial locations to dynamically change the compression chamber volume. The piston is biased by a spring and can be moved axially to engage or disengage from the scroll, enabling the compressor to switch between full capacity and reduced capacity modes. This dynamic adjustment allows the compressor to adapt to varying load conditions and improve energy efficiency without requiring a completely different compression mechanism.
2Productivity
If a compressor lacks capacity modulation mechanism, then the device complexity is low, but the performance deteriorates in providing cooling and heating effects
Solution Approach 1:
The compression system is segmented into two operational states: full capacity mode where the piston is engaged with the scroll, and reduced capacity mode where the piston is disengaged. The piston-retention member creates distinct engagement positions that segment the operational range, allowing the system to provide different cooling/heating capacities by simply changing the piston's axial position rather than requiring a complex multi-stage compression system.
Solution Approach 2:
The piston acts as an intermediary element between the scroll compression mechanism and the discharge chamber. By moving the piston axially, it intermediates the compression process - when engaged, it creates a sealed compression chamber for full capacity operation; when disengaged, it allows the compression chamber to expand for reduced capacity operation. This intermediary mechanism enables capacity modulation without fundamentally changing the scroll compression principle.
3Adaptability or versatility
If the piston is freely movable, then the capacity modulation is flexible, but the reliability deteriorates due to improper engagement
Solution Approach 1:
A spring is positioned to bias the piston toward the engaged position before operation begins. This spring pre-load ensures that the piston is reliably held in the engagement position during normal operation, preventing accidental disengagement. The spring acts as a cushioning force that maintains consistent contact between the piston and the scroll, ensuring reliable sealing and engagement throughout the compression cycle.
Solution Approach 2:
The piston-retention member with its ratchet mechanism provides self-locking engagement. Once the piston is moved into the engaged position, the ratchet teeth on the piston engage with the corresponding features on the retention member, creating a self-locking mechanism that maintains engagement without requiring continuous external force or control. The spring continuously applies biasing force to ensure the ratchet remains engaged, making the system self-regulating and reliable.
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 enhances the compressor's ability to efficiently switch between capacity modes, improving energy efficiency and performance by ensuring proper engagement and separation of scrolls, thereby optimizing the compression process and reducing operational noise and vibration.
Implementation Method 1
The pressure chamber may be in selective fluid communication with a first source of working fluid to control movement of the piston relative to the shell assembly
Implementation Method 2
a spring engages the piston-retention member and the rotationally fixed structure. The spring biases the piston-retention member into engagement with a selected one of a plurality of notches
Implementation Method 3
The piston-retention member allows rotation of the piston relative to the first scroll in a first rotational direction and restricts rotation of the piston relative to the first scroll in a second rotational direction
Data Source
AI summary
A compressor may include a shell assembly, a first scroll, a second scroll, a piston, and a piston-retention member. The piston engages the first scroll and may be partially received within a recess defined by the shell assembly. The piston and the shell assembly may cooperate to define a pressure chamber. The pressure chamber may be in selective fluid communication with a source of working fluid to control movement of the piston relative to the shell assembly. The piston-retention member may be mounted to the piston and selectively engage a rotationally fixed structure. The piston-retention member allows rotation of the piston relative to the first scroll in a first rotational direction and restricts rotation of the piston relative to the first scroll in a second rotational direction.