Shaft system to find the methods and technical requirements

Axis 2019 - to find the method and technical requirement 06 - 26 shafting is looking for and shafting alignment shafting installation of two key links, and shafting for shaft system is the premise and foundation of the school, in the process of shipbuilding technology content high, influence factors, the process is relatively complicated, in the event of failure rework, time lost and huge economic losses, and failure root cause analysis difficult. Purpose is through the positioning of shafting for stern tube bearing to determine the shafting actual center line conform to the requirements of the center line of the theory. The commonly used method, which has two kinds of arrows and light method. Pull method should be reasonable selecting wire specifications and hanging heavy, and calculate the corresponding points of steel wire deflection, steel wire choose commonly 0. 50 - 1. 0 mm and avoid exist terrier knot, flex and the attachments, the greater the prestressing force of steel wire line, thread accuracy is higher, but the hanging weight exceeds a certain value, the steel wire is easy to break the general in order to prevent the wire line break, hang heavy usually take about 80% of the steel wire tensile force; And light method need not consider wire deflection, but I need the light tools such as optical or laser theodolite, and need so require researchers can use related instrument build solid platform for the light, this method especially for long shaft is recommended. Position of the stern shaft tube bearing at present commonly used process are: stern shaft tube and hull welding after the boring process and after finishing the assembly of stern tube assembly using epoxy pouring positioning technologies. Stern tube boring process, namely through the pull method or the light method before and after the stern tube bore and inspection, to find the basis as boring, boring circle can also be fine for stern tube and the final size of the reference, and after test can also be used as the basis for double line. Pay special attention to in essence in boring boring, The last few feed) Should choose to night or rainy weather, at the same time avoid stern have larger vibration other simultaneous engineering and should choose the cutting tool to ensure higher precision boring accuracy. Boring process of double line should be in front of the light car stern tube, namely the destruction test round before, to test for double line basis, to avoid duplication guy; Stern tube assembly epoxy pouring positioning process, namely through the pull method or the light method to pinpoint the location of the stern shaft tube and then approved by pouring epoxy makes stern tube fixed on the hull, therefore in the shaft system for process and epoxy pouring process should be approval at the same time, should also pay attention to the epoxy pouring is a one-time project, are not allowed to appear rework phenomenon, so the precision must be strictly controlled, should consider the various factors may affect the accuracy or risk, such as, should choose the still of the night or rainy weather should stop if all other engineering in order to avoid the risks of vibration; Stern shaft tube positioning inspection should be done in sync with epoxy pouring, casting the next day of avoid by all means to avoid serious deviation or departure from hull vibration, due to the shaft system for inspection in other mechanical and electrical engineering is usually a large number of simultaneous, poor working conditions, the next day the vibration of the other project will bring serious deviation, if unavoidable, should still find again just before the pouring epoxy in quarantine; Epoxy pouring shall require at least 24 hours after the completion of the shipyard to stop the wheel of all engineering, at least stop may bring vibration engineering; Poured riser choice is very important also, sprue and riser should as far as possible away from, riser should choose in relative to the highest position, if necessary can select multiple gate and riser; Inspection, of course, you should also check with epoxy product certificate or type approval certificate of conformity of the product itself, the construction personnel qualification certificate; Casting process should be randomly selected from one or more block, to check the hardness of epoxy. Epoxy pouring position of double line, should be on the advice of the epoxy producers in epoxy pouring at least 24 hours after the initial curing or general 48 hours after curing, finally find the median will be subject to double track data, any error shall be recorded. Because of shafting find did not include in the specification and the standard description inaccurate or discrepancy is bigger, cause different shipyard in the practical construction, the practice of construction group each have each different, each technical experts, engineering and technical personnel understand also each are not identical, more controversy. Shafting find a link in the process is more, every small part deviation bring risk to the safety of the shaft system, once more than little risk of overlay design redundancy will lead to serious fault or accident. Such as shaft can be find in the requirements of the standard unified and clear, and can regulate and improve, which can effectively avoid in the process of shaft system to find the differences and disputes, and thus to minimize impact on the follow-up of shafting school, ensure shafting actual construction meet the design requirements. （ Source: the journal survey of China)