| 摘要 |
A supporting mechanism for a casing hanger improves the load withstanding ability. The casing hanger (33) is located in a wellhead housing (11). A recess (17) is formed in the bore (13a, 13b) of the wellhead housing with an upward facing shoulder (15) extending into the bore. An insert ring (19) is stationarily and rigidly mounted in this recess. The insert ring has a load shoulder (25) on its upper side. The load shoulder (25) of the insert ring is considerably less in width than the recess shoulder (15). However, the insert ring (19) has a greater hardness to increase the capacity of the insert ring. The casing hanger (33)has an exterior load ring (37) that lands on the insert ring (19). The load ring has threads (47) which are cut to have clearances initially between the load flanks. A clearance also exists between the upper end of the load ring (37) and a downward facing shoulder (36) on the casing hanger. A protuberance (51) on the upper end of the load ring maintains this upper clearance until the load flank clearances close up, then allows the upper clearance to close up to assure loading through the flanks.
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