Radial Piston Compressor Transmission Element Force Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piston-cylinder assemblies for radial piston compressors, particularly for refrigerant CO2, face issues with high surface pressures leading to wear and premature component failure, especially in the regions of the piston pin, connecting rod eye, and receiving bore for the piston pin.
Innovation Solution
The piston-cylinder assembly incorporates a transmission element with a form-fitting connection to the piston, utilizing a concavely shaped operative surface on the piston and a convexly shaped supporting surface on the transmission element, along with a piston guide ring for return movement, to distribute forces and reduce surface pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a piston pin and connecting rod design is used to transmit forces, then the piston stroke movement can be achieved, but very high surface pressures occur leading to wear and premature component failure
Solution Approach 1:
The force transmission path is segmented into multiple contact surfaces: the transmission element has a first supporting surface contacting the eccentric and a second supporting surface contacting the piston, distributing the force across different areas rather than concentrating it through a single piston pin connection
Solution Approach 2:
The transmission element is designed with extended surfaces in the radial direction, transitioning from point contact (piston pin) to surface contact, thereby adding dimensional extent to the force transmission interface and reducing surface pressure
2Ease of operation
If the receiving bore for the piston pin is made in the piston, then the piston pin connection is achieved, but the piston is mechanically weakened
Solution Approach 1:
The piston pin connection is extracted from the piston body and relocated to a separate transmission element, eliminating the need for a receiving bore in the piston and preserving the piston's structural integrity
Solution Approach 2:
A transmission element is introduced as an intermediary component between the piston and the eccentric, serving as the force transmission medium while avoiding the need to weaken the piston structure with a receiving bore
3Productivity
If high compression pressures are used for refrigerant CO2, then the compression performance is improved, but wear and component failure occur due to high surface pressures
Solution Approach 1:
The high compression forces are segmented and distributed across multiple contact surfaces (first supporting surface with eccentric, second supporting surface with piston) rather than concentrated at a single point, reducing surface pressure and preventing wear even at high compression pressures
Solution Approach 2:
The contact geometry parameters are changed from point contact to extended surface contact in the radial direction, altering the pressure distribution and enabling high compression performance without compromising component durability
Data Source
AI summary
The present invention relates to a piston-cylinder assembly for a radial piston compressor. The piston-cylinder assembly comprises a drive shaft with a cylindrical eccentric for guiding the movement of the piston to a top dead center position. A cylindrical piston guide ring guides the movement of the piston to a bottom dead center. Both the cylindrical eccentric and the piston guide ring are connected to the piston by means of respective concave/convex contact surfaces for the positive transmission of the forces.