특수 목적 차량의 수상 추진체용 카단 샤프트의 유니버셜 조인트에 대한 응력 및 수명 평가

Abstract

The powertrain of the waterjet system of a special-purpose vehicle makes use of the cardan shaft, which is composed of universal joints and shafts. These universal joints, composed of spiders and needle roller bearings, have to be designed with consideration for the bending and compressive stresses of the spiders and needle roller bearings, and the rating lives of the bearings. The bending and compressive stresses of the spider and bearing of a universal joint have been studied by many researchers. However, to design a universal joint effectively, overall consideration of the different specifications of needle roller bearings is necessary. In this study, the bending stresses of spiders and compressive stresses of needle roller bearings are calculated to design universal joints for powertrain cardan shafts with different roller diameters of bearing. Furthermore, the rating lives of the needle roller bearings are predicted using the calculated basic dynamic load ratings of the bearings. As a result, roller diameters less than φ2.5 mm are found suitable through an analysis of the bending stress of the spider. All compressive stresses between spider and bearing, regardless of roller diameter, satisfy the requirements. Moreover, roller diameters of more than φ2 mm are found suitable for the required rating life.