6926475967

Caterpillar Tractor Co., East Peoria. IL. SAE Paper No. 821042

Key Word*: Geers, Fatigue tests, Testing tachniqu«s

A single tooth bending fstigue (STBF) technique for testing factors which could affect the fstigue IKe of geers hss been developed. The test fixture and testing techniku* deseribed in this peper were developed because of the larga vsristbns in test procedurę and specimen design used throughout the industry. These uariations csuse difficulty in determining relative importance of metsllurgicsl factors on fstigue life of hardened geers. Four co m pen i es participsted in a round robin testing program using the identically designed fixtures to show how reproducible and sensithre the technique is to metallurigcal factors affecting fstigue life of geers.

841679

lxnprovement on the Fstigue Strength of Case Hird* ened Cesrs by s New Hest Treatment Proces*

K. Nakamura, K. Mihara, V. Kibayashi. and T. Naito Technical Research Ctr., Konnatsu Ltd., SAE Paper No. 821102 (SP-522)

Key Words: Geers, Fstigue life

Retained austenite in the surface of carburized or carboni-trided Steel improves the pitting resistance of the Steel under rolling contact, although some deterk>rative affect on the bending fatigue is reported. The aim of this study is to make elear the influence of retained austenite content on the pitting and on the bending fatigue, and also to develop a beat treeting proces* which enable* quantrtative contro) of retained autfenite on the surface of geers.

84-1680

Prediction of Fatigue Life of Spiral Teeth through Analyas of Finite Element* and Experimental Check*

D. Barbiero. A. Garro, and F. Rossi

Fiat Auto S.p.A., Dire2ione Tecnica. Sviluppo Pro-

gett i. SAE Paper No. 820781

Key Words: Gear teeth, Geer boxes, Fatigue IKe, Flnłte element technique

During initisl gearbox design, the present trend is to u*e geers with Uttle diametral płtch and less valuable Steel; first for noise problem* and then for economłcal and politicel raasons oonnected with the strategical availability of some alloy materiał*. These reasons brought the teeth limit of fatigue to minimum required values for gearbox endurance and new methods of calculation were developed morę and morę aophisticated than old ones. The peper describes the theoreticai approach to the stress calculation and discusaes the possibility of comparing the calculated data with the fatigue tests and the relsted actual performance* of the gaars in the case of different heat treeting or surface finishing conditions.

84-1681

A Basic Approach to Gearbox Noise Prediction

L.D. Mitchell and J.W. Daws

Virginia Polytechnic Inst. and State Univ., 8lacks-burg. VA, SAE Paper No. 821065 (SP-523)

Key Words: Geer boxes, Noise prediction

An overview of a strategy for the prediction of noise from industrial gearboxes is provided. A review of the history of predictive noise control in geerboxes is given. This paper details the computational strategy for the determination of the dynamie response of the internal gearbox components. The epproaches presented here are significant depertures from those carried out in the past.

84-1682

Simulation on RoUtional Yibration of Spur Gears

K. Umezawa. T. Sato, and J. Ishikawa Tokyo Inst. of Tech., Res. Lab. of Precision Ma-chinery and Electronics, Nagatsuta, Midori-ku. Yoko-hama. Japan, Buli. JSME. 21 (223). pp 102-109 (Jan 1984) 12 figs, 19 refs

Key Words: Geers, Geer teeth, Spur gears, Vibration analy-sis, StKfness effects. Geometrie Imperfection effects

This peper introduces a developed Simulator on rotational vferatk>n and strein at the root of a tooth on a powtr trans-misslon spur gear. The Simulator solves a differential aqua-tion with one degree of freedom in consideration of tha behavk>r of the stKfness around tooth tip ma*hing. Th* stKfness function is discussed and determined with static and dynamie merfting tests under loed. Tha arrors of the gears are put into the Simulator with a newly d*vetoped autometic geer accuracy meesuring instrument.

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