Adjacent cylinder sealing device for gradation type reciprocating compressor or expansion machine

Abstract

The invention discloses a device for sealing adjacent cylinders of stage differential type reciprocating compressor or expander, which comprises a cylinder block and a cylinder arranged therein. The device is characterized in that the inner wall of the cylinder is provided with multiple groups of superposed sealing components which are composed of sealing rings and limiting seats, the limiting seats are in ring structure and are provided with annular grooves on the inner walls, and the sealing rings are inlaid in the annular grooves; the inner circular working surface of the sealing ring is provided with a wedge form notch adjacent to high pressure side, the periphery of the inner circular working surface is provided with a unloading groove, and a pressure guide hole is disposed between the high pressure end surface and the unloading groove. The sealing device adopts a mode of superposing and inlaying multiple groups of sealing components on the inner wall of the cylinder, achieves the sealing of the piston and the cylinder, adopting the structure, the piston need not to be provided with piston ring groove, and the number of the sealing components mounted on the cylinder wall can be determined by the pressure difference of two sides of the piston, the mounting is convenient and flexible, the sealing components can be composed by assembling sealing rings and limiting seats which can be mounted separately, and the maintenance or part replacement is very easy.

Description

technical field [0001] The invention belongs to the field of fluid machinery, and relates to a cylinder sealing device, in particular to an adjacent cylinder sealing device of a differential reciprocating compressor or an expander. Background technique [0002] The sealing problem has always been a key factor affecting the efficiency of the reciprocating compressor (or expander). In the case of high pressure and no oil, the impact of the sealing quality on the performance of the machine is more prominent. In a traditional differential reciprocating compressor (or expander), the adjacent cylinders with pressure difference are sealed by several notched piston rings. A typical piston ring uses its notches to fit the ring to the inner wall of the cylinder to avoid gas leakage between the piston and the cylinder. However, the opening of the piston ring needs to leave a certain gap to compensate for the thermal expansion of the piston ring. If the gap is too large, it will cause ...

AI Technical Summary

Problems solved by technology

However, the opening of the piston ring needs to leave a certain gap to compensate for the thermal expansion of the piston ring. If the gap is too large, it will cause a large amount of gas leakage, and if it is too small, the piston ring will be stuck due to thermal expansion. However, it is difficult to control the gap between the openings of the piston ring in actual design and processing.

In addition, when the piston ring is attached to the cylinder by its own tension, it cannot guarantee a complete fit with the inner wall of the cylinder in theory, resulting in an unsatisfactory sealing effect.

Under the high pressure difference, each piston ring has to bear a relatively large pressure difference, especially the first piston ring close to the high pressure side needs to bear a larger pressure difference than other piston rings, which results in large friction and fast wear of the piston rings. Easy to fail, directly affecting the reliability and economy of the compressor

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