Eccentric Sliding Component with Dynamic Pressure Grooves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In scroll compressors, the frictional resistance increases due to pressing forces on sliding surfaces undergoing eccentric rotation, hindering smooth operation and compression efficiency.
Innovation Solution
Sliding components with pressure generation regions on their surfaces, allowing separation during eccentric rotation by generating positive and negative pressures, reducing friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pressing forces are applied from both axial sides to reduce leakage from the axial gap between scrolls, then leakage reduction is achieved, but frictional resistance on sliding surfaces increases
Solution Approach 1:
The patent introduces a thrust bearing that utilizes fluid pressure (pneumatics/hydraulics) to support the axial load between the movable scroll and fixed scroll. Instead of direct mechanical contact with high friction, a fluid film is generated through pressure generation grooves on the thrust plate, creating a hydrodynamic bearing that reduces frictional resistance while maintaining the necessary pressing force to prevent leakage from the axial gap.
Solution Approach 2:
The patent changes the pressure distribution parameters on the sliding surface by incorporating pressure generation grooves with specific patterns (radial grooves, circumferential grooves, or spiral grooves). These groove configurations alter the fluid pressure field, generating positive pressure in specific regions to support the thrust load while controlling the overall friction characteristics of the sliding interface.
2Reliability
If pressing forces from both axial sides act on sliding surfaces undergoing eccentric rotation, then leakage is reduced, but smooth operation is hindered due to increased friction
Solution Approach 1:
The thrust bearing employs hydrodynamic lubrication where the relative eccentric rotation between the movable scroll and fixed scroll generates fluid pressure in the grooves, creating a lifting effect that separates the sliding surfaces. This pneumatic/hydraulic mechanism enables smooth operation during eccentric rotation while maintaining sufficient contact pressure to prevent leakage, resolving the contradiction between smooth operation and leakage prevention.
Solution Approach 2:
The thrust bearing design accommodates the dynamic eccentric rotation motion by using grooves that generate dynamic pressure during relative motion. The pressure generation is not static but dynamically adjusted based on the rotation phase and load conditions, allowing the bearing to adapt to the changing operational state and maintain both smooth operation and effective sealing.
3Productivity
If compression efficiency is improved by reducing leakage, then compression performance increases, but frictional resistance on eccentrically rotating sliding surfaces increases
Solution Approach 1:
By implementing a thrust bearing with pressure generation grooves that utilize fluid pressure to support axial loads, the patent reduces frictional resistance on the sliding surfaces. This reduction in friction directly improves compression efficiency by minimizing energy losses, while the bearing simultaneously maintains sufficient pressing force to prevent leakage and ensure reliable compression performance.
Solution Approach 2:
The patent replaces the traditional high-friction mechanical contact system with a fluid-film-based thrust bearing system. This substitution eliminates direct solid-to-solid contact friction by introducing a fluid intermediary, thereby improving compression efficiency while maintaining the necessary mechanical function of supporting axial loads and preventing leakage.
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
Stable reduction in frictional resistance and improved sliding performance by utilizing pressure generation grooves and dynamic pressure distribution.
Implementation Method 1
at least one of the sliding surface of the fixed component and the sliding surface of the orbiting component has at least one pressure generation region where pressure is generated during relative rotation due to the eccentric rotation
Implementation Method 2
sliding surfaces that slide relative to each other as the sliding surfaces undergo eccentric rotation
Data Source
Figure 1
Figure 2
Figure 3
AI summary
There are provided sliding components capable of stably reducing the frictional resistance of sliding surfaces that undergoes eccentric rotation. In sliding components consist of a fixed component 8 and an orbiting component 7 which have sliding surfaces that slide relative to each other as the sliding surfaces undergo eccentric rotation, at least one of a sliding surface 8a of the fixed component 8 and a sliding surface 7a of the orbiting component 7 has pressure generation regions 80 and 81 where pressures are generated during relative rotation due to the eccentric rotation.