Alın dişlilerin maliyet bakımından incelenmesi

Abstract

Alın dişliler endüstride çok b üyük miktarda imal edilmekte ve kullanılmaktadır. Hemen hemen her ma k inada kullanılan bu makina elemanından beklenen, kabul edilen bir çalışma süresi içinde dişlerinin kırılmaması, diş profillerinin aşınmaması ve emniyetle görevini yapabilmesidir. Bunun yanında imal edilecek dişlinin ucuz olması istenir. Dişli maliyetinin optimum bir değerde tutulabilmesi ancak kostrüksiyon sırasında alınacak kararlar ve tedbirler neticesinde mümkün olacaktır. Bu çalışmada dişlilerin maliyetini etkileyen faktörler ve maliyet bakımından uygun konstrüksiyonun nasıl yapılması gerektiği konusu araştırılmıştır.

Transmission of energy have a great importance by the mechanical engineering. This can be carried out by different mechanism. One of them and the most useful is the spur gears. Speed and torque of the rotation are transformed by this mechanism. Gear teeth are subjected to reversed stress. In order to work the mechanism safely it should work a certain time without any tooth breakage and any failure. Designing gears presents an extremly difficult problem because it is primarily a trial and error procedure. However» there are several methods that can be used to developed a design Gears generally fail because the actual loads applied to the teeth are greater then the allowable loads based upon either the beam strength of the tooth C tooth fracture ) or its wear strength C surface failure ). Therefore teeth are designed durable to breakage and surface destruction. The following types of surface destruction usually lumped together under the general term wear: are 1). Abrasive Wear : A failure due to the presence of foreign material in the lubricant that can scratch the tooth sur face. 2). Corrosive Wear : A failure due reaction on the tooth surface. to the chemical 3). Pitting : A fatique failure due to application of stress cycles. the repeated 4). Scoring : A failure due to the metal- to-metal contact attributable to lubricant failure. In designing a gear, the material chosen must have an endurance limit large enaugh to resist the repeated dynamic load gear teeth are subjected to. -V- For parallel shaft applications, either spur or helical gears, the designer is advised to use spur gears wherever feasible. A reasonable rule to follow is to use spur gears for low speed applications and helical gears for high speed applications. Clearly then, the first design step is to choose the proper type of gear. Without doubt, cost is an extrenuLy important factor in design. Achievement of an economical design depends on the designer's experience, knowledge, ingenuity, and ability. For an economical design, designer should know the influences on the production costs and the possibilities of the reduction of the costs. In order to gain clearness about substantial influences on production costs of spur gears, some researches are made C for example by the German Power Transmission Engineering Research Association FVA ). To evaluate draft and variant proposals, a cost estimate is highly important. Often conventional precalculations require too much time and effort. Furthermore the design engineer must be acquainted with cost structures, i.e. the cost percentage of individual design factors, to able to effect a cost decrease. In this study provides an overview to aid understanding of their structure.