Function of the guide ring on the compressor piston
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What would happen if there were no guide rings? The compression direction of the piston within the cylinder is already determined by the cylinder itself; then why are guide rings needed?
Does the guide ring mentioned by the original poster refer to the support ring? Pistons are typically equipped with support rings and piston rings, and the function of the support rings is to provide support and guidance!
I’m not sure whether it’s a guide ring or a support ring. Does this support ring serve to hold the piston in place? And how does the guide ring function as a guide?
Firstly, the guide ring serves a guiding and positioning function. It ensures the linear motion of the piston within the cylinder as well as the concentricity between the piston and the cylinder, maintaining a certain working clearance between them and preventing wear and scratches on the cylinder surface caused by direct contact between the piston and that surface.
This post was last edited by zdl1966 on 2017-11-11 at 17:53. Secondly, the guide ring is used to withstand lateral pressures and support the weight of the piston assembly. In angular compressors, since there is no crosshead, the combined piston force is transmitted to the piston pin through the connecting rod, resulting in a component force at the piston pin that acts perpendicularly on the cylinder wall via the piston; this force is known as side pressure. In oil-free lubrication compressors, the piston rings are made of non-metallic self-lubricating materials and have relatively low strength. Moreover, to ensure sealing performance, their axial thickness is small; therefore, oil-free piston rings generally serve only a sealing function, while the side pressure is mainly borne by the guide rings. In horizontal or angular compressors, all or part of the weight of the piston assembly is also borne by the guide ring; hence, the guide ring is also known as a support ring. The presence of the guide ring improves the working conditions of the piston rings, enhancing their sealing performance and service life.
The guide ring serves a supporting role, holding up the weight of the piston. Without a guide ring, the cylinder will be damaged.
Don’t piston rings provide support? Or do they mainly serve a sealing function?
As the name implies, the support ring serves a supporting and lubricating function, while the piston ring is used for sealing. They are installed at an angle of 180 degrees apart; the opening size and side clearance are important, and these should be measured based on actual conditions
You mean the trunnion, right? Its main function is to support the weight of the piston and to align the piston with the center of the cylinder!