The Effect of Shaft Diameter and Hole Tolerance on Stress Distribution in Micro Module Gear-Shaft Interference Fitting Connections

Öz

One of the widely used machine elements in machine design and manufacturing is gears, and in many areas, the use of various sizes of gears is needed. Micro module gears with module 1mm and smaller are used as an important machine element in precision measuring instruments, defense industry and machine manufacturing. Damage to the gear surface, gear teeth, gear body and gear-shaft connection during power transmission affect the normal operation of the entire machine. Any damage that may occur can damage not only the gear or gear connection, but also many machine parts that work with this machine elements. Due to the dimensions of the micro-module gears, the interference-fitting connections come into prominence in the gear-shaft connection. However, there are important shortages in the literature. Designers practicing all interference-fitting connections can lead to both time and economic losses. For this reason, the analytical and numerical calculations are of great importance in the gear hub shaft interference fitting connections.

In this study, the stress distributions are calculated and compared numerically and analytically that occur at different interference fit tolerances and different hub diameters for micro module gear having 20 teeth number, 6mm width and 1mm module. The data obtained from the analytical and numerical studies are in agreement with each other. Axial and radial stress decreases as the nominal diameter increases. At this point, however, the weakened gear surface is vulnerable to damage. For all nominal diameter values used in the study, the axial and radial stress magnitude caused by the gear shaft connection are listed as H7/u6, H7/s6, H7/p6, respectively.

Anahtar Kelimeler

• micro module gear
• interference fitting
• gear-shaft connection

Mikro Modüllü Dişli-Mil Sıkı Geçme Bağlantılarında Mil Çapı ve Delik Toleransının Gerilme Dağılımına Etkisi

Öz

Makine tasarımı ve imalatında yaygın kullanıma sahip makine elemanlarından biri dişliler olup birçok alanda çeşitli boyutlarda dişli kullanımına ihtiyaç duyulmaktadır. Modülü 1mm ve daha küçük olan mikro modüllü dişliler ise, hassas ölçüm aletlerinde, savunma sanayinde ve makine imalatında önemli bir makine elemanı olarak kullanılmaktadır. Güç aktarımı sürecinde dişli yüzeyinde, dişte, dişli gövdesinde ve dişli-mil bağlantısında meydana gelen hasarlar, tüm makinenin normal çalışmasını etkilemektedir. Oluşan herhangi bir hasar yalnızca dişli ya da dişli bağlantısını değil, bu elemanla birlikte çalışan birçok makine parçasını da hasara uğratabilir. Mikro modüllü dişlilerin küçük boyutları nedeniyle dişli-mil bağlantısında sıkı geçme bağlantıları ön plana çıkmaktadır. Ancak bu konuda literatürde önemli eksiklikler bulunmaktadır. Tasarımcıların tüm sıkı geçme toleranslarını uygulamalı olarak denemesi hem vakit hem de ekonomik kayıplara yol açabilir. Bu sebeple analitik ve nümerik hesaplamaların, dişli göbeği mil sıkı geçme bağlantılarında önemi büyüktür.

Bu çalışmada, farklı göbek çaplarına sahip 1mm modül, 6 mm genişlik ve 20 diş sayısına sahip bir mikro modül dişlide; farklı sıkı geçme toleranslarında oluşan gerilme dağılımları sayısal ve analitik olarak hesaplanıp karşılaştırılmıştır. Analitik ve sayısal çalışmadan elde edilen veriler birbiriyle uyum içerisindedir. Nominal çap arttıkça meydana gelen teğetsel ve radyal gerilme azalmaktadır. Ancak bu noktada zayıflayan dişli gövdesi meydana gelebilecek hasarlara açık konumdadır. Çalışmada kullanılan tüm nominal çap değerleri için dişli mil bağlantısından ötürü meydana gelen teğetsel ve radyal gerilme büyüklüğü H7/u6, H7/s6, H7/p6 şeklinde sıralanmaktadır.

Anahtar Kelimeler

• mikro modüllü dişli
• sıkı geçme
• dişli mil bağlantısı

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