A method for improving the carrying capacity of rack and pinion lifting device of self-elevating platform

Abstract

The invention relates to a method and a measure for improving the carrying capability of a lifting device of a self-elevating type platform gear rack. The main method and the measure are as follows: according to the number n of driving pinions arranged at single side of a rack of the lifting device, the engagement phase difference of the adjacent driving pinions and the rack is reasonably set to be 360 / 7n (n is the odd number or the even number) or 25.71 degrees (i.e. 360 / 14, only n is the even number), and meanwhile, the contact edge of the rack is subjected to right-angle chambering or round corner chambering, wherein the driving pinions in the lifting device adopt the tooth form with great modulus and high deflection. After the method and the measure are adopted, the maximum stress during the single-tooth engagement of the gear rack can be reduced to a great degree, and the problem of stress concentration at the contact surface of the rack is solved, so the stress state of the gear rack of the lifting device is improved, and the service life is greatly prolonged.

Description

technical field [0001] The invention relates to a method and measures for improving the carrying capacity of a jack-and-pinion lifting device of a self-elevating ocean platform, and belongs to the field of ocean engineering. Background technique [0002] The jack-up platform refers to the equipment used for offshore oil and gas development or to serve offshore oil and gas development. It has the advantages of strong positioning ability, good mobile operation stability, and low cost. It has become the main force of continental shelf oil exploration and development. The relative movement of rising or falling between the main hull and the legs is its biggest feature. At present, there are two main lifting methods for self-elevating platforms: 1. The hydraulic cylinder jacking method, through the mutual cooperation of the main and auxiliary hydraulic cylinders, the lifting of the platform is realized. However, due to the inability to achieve continuous lifting, there are disadv...

AI Technical Summary

Problems solved by technology

In the traditional rack and pinion lifting mechanism, the phase angles between different active pinions are the same. Under different meshing states, the contact surface stress between the active pinion and the rack and the bending stress of the pinion change greatly. Under the action of alternating stress, it is easy to Cause fatigue damage to the rack and pinion; and in order to prevent the rack and pinion from slipping when meshing, it is generally required that the tooth width of the gear is greater than the tooth width of the rack. The rack should not be widened to reduce the contact surface stress. At the same time, the maximum contact stress Occurs at both ends of the contact part of the rack, prone to stress concentration

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