A Rapid Manufacturing Method for Rectangular Splines Based on Laser Cutting and Welding

Abstract

Highlights A rapid manufacturing method for internal and external rectangular spline shafts for use in agricultural machinery was developed using a combination of laser cutting and welding. The shear strength of the internal spline welds, extrusion strength of the spline tooth surfaces, and extrusion and shear strength of the external spline pins were tested. Threshold values were obtained for the average diameter of the internal and external splines. Two case studies (light load and heavy load) were performed to verify the feasibility and reliability of the method. Abstract. In recent years, special-sized spline shafts and gears have been widely used in the trial production of new agricultural machinery in China. However, due to the high production cost and long development cycle of these common components, the development of new agricultural machinery has been affected. To solve these problems, this article proposes a method for rapid manufacturing of rectangular internal and external splines using a combination of laser cutting and welding. Through analysis of the weld shear strength of the internal splines, the extrusion strength of the spline tooth surfaces, and the extrusion and shear strength of the external spline pins, it was calculated that the threshold of the average diameter (dm) of the internal splines, commonly used in agricultural machinery, was dm ≥ 31.17 mm, and that of the external splines was dm ≥ 33.45 mm. The feasibility and reliability of the method were verified with two case studies using light and heavy load conditions. The light load case study was the splines of the power input shaft of the pickup platform of a peanut harvester, and the heavy load case study was the splines of the total power input shaft of a peanut no-till planter. The case studies indicated that under the light load conditions (average power of 1.13 kW, average torque of 64.1 N·m, average speed of 168.7 rpm, cumulative working time of 48 h, and harvested area of 46.4 ha) and heavy load conditions (average power of 89.36 kW, average torque of 1029.9 N·m, average speed of 828.6 rpm, cumulative working time of 51.5 h, and planted area of 31.7 ha), no spline failure was observed, and the reliability was 100.0%. This article provides a technical reference for the rapid production of special-sized rectangular splines as single pieces or in small batches for trial production, which requires low processing accuracy, of new agricultural machinery products.