Connecting method of crosshead piston rod in reciprocating compressors
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Our company’s reciprocating compressors use coke oven gas as the working medium; they feature two stages of compression, with an outlet pressure of 4.4 MPa at the second stage. The gas handling capacity is 39,500 Nm3/h. The piston rod is connected to the crosshead using super nuts, and over the course of two years of operation, breaks often occurred at the threads where the piston rod and crosshead are connected. We are seeking a better, more reliable connection method.
Keyed connections or tapered connections can be considered; both are more reliable and robust than super nut connections. Keyed joints can better withstand alternating loads, while tapered joints provide a larger contact area, thereby increasing the stability and strength of the joint. It is also recommended to examine and optimize the material and machining precision of the piston rod and crosshead, to ensure high fitting accuracy and reduce fracture issues caused by vibration and stress concentration. .
It is already a very mature method of connection. It broke down because of installation issues. Issues such as poor contact between the locking surfaces of the pin and shaft, inadequate tightening of the lock nut, and debris in the threads, etc. Also, it is necessary to check whether maintenance was carried out before the first fracture occurred two years later, and whether there were any cylinder collision incidents that caused misalignment in the engine’s structure. For reference.
Germany has a type of piston rod with a crosshead connection that uses a hydraulic structure. Domestic manufacturers have adopted them.
Are there any materials on key connections or tapered connections?
It would be best to send a video for easier discussion.
A schematic diagram was found; specific requirements still need to be calculated by a professional agency.
Hydraulic nut connection. The piston rod must be installed vertically and horizontally as required, to ensure that the slide rail is concentric with the cylinder.
It is crucial to check for any liquid accumulation after the installation and commissioning are completed successfully