DIRECTIONS AND RESERVES OF RAM-TYPE STEERING GEAR WITH TANGENTS-TYPE MECHANISM TECHNICAL LEVEL

Abstract

Article deals with one of most commonly used ram-type steering gears. On the basis of theoretical analysis main disadvantages of ram-type steering gears are highlighted. Main of them are low mechanic efficiency, high details load, lot of redundant connections in steering gear lever mechanism structure. So, main purpose of the article is to show main directions and to access reserves of ram-type steering gear equipped with tangential lever mechanism technical level increasing. Main tasks for purpose achievement are: to define main criteria of ram-type steering gear mechanism technical level, that take into account structure perfection, its operation energy efficiency and also details load; to evaluate that criteria for widespread ram-type steering gears; to outline directions of ram-type steering gears technical level increasing and access reserves of its application. Done structure analysis showed that that number of redundant connections in steering gear YOOWON-MITSUBISHI YDFT-335-2 lever mechanism is 20. Reason for having such redundant connections number is kinematic pairs connecting plungers and guide beams and low class of most kinematic pairs. Reserve for decreasing redundant connections number is upgrading kinematic pair class and refusing of guide beams. It is shown that in time of rudder feather shifting from diametric plane to board (when α = 5…35º), guide beam could take only 5…7% of lateral force. The source of origin significant loads on plungers in ram-type steering gears is application of tangents-type mechanism for transformation progressive plunger motion to rotating tiller motion. Decreasing lateral loads on plunger through using unloading guide beams, with considering low unloading percent is ineffective. Guide beams availability complicates steering gear construction, increasing number of friction surfaces and trough this complicates steering gear maintenance. It is shown that friction losses in plunger gaskets is 39% of all friction losses. Reserve to decrease gaskets losses is transition from ram-type to piston-type stock equipped construction. Main result is that increasing of ram-type steering gear technical level need to change the type of mechanism for transformation progressive plunger motion to rotating tiller motion from tangents-type to another.