1. Five axis NC machining
Five axis NC machining is a technology with high technical content and the widest machining range in NC technology. It integrates computer automatic control, servo system and finish machining, and is used to process complex surfaces. The five axis NC machine tool has at least five coordinate axes, which can be processed under the control of the computer NC system, and its processing is precise and efficient. Therefore, using five axis NC machine tool to process involute ring gear ball gear pair should be a feasible scheme, which can realize high efficiency and high precision machining. Wang Qi once put forward the technical principle of machining ball gear with five axis NC Hobbing Machine. This method can significantly improve the machining quality and accuracy of workpiece and reduce labor cost, which is easy to be widely used by manufacturers.
2. Additive manufacturing (3D printing)
The tooth profile of involute ring gear ball gear is a complex profile. If its machining accuracy is low and its quality is not high, the gear will produce vibration noise and low bearing capacity. With the development of additive manufacturing (3D printing) and its wide application in industry, 3D printing should be the preferred method for the processing and manufacturing of high-precision involute ring gear ball gear in the future.
2.1 Melt lamination rapid prototyping (FDM)
The research object of molten layer rapid prototyping technology is three-dimensional model. According to different technical requirements, the processing parameters are set, and the layered profile data of each profile are processed according to a certain thickness. According to the processing information, the system controls the nozzle to squeeze layer after layer of filamentous materials to form a series of solid sheets with small thickness. Each plate is gradually stacked into an organic whole through sintering, aggregation and bonding to obtain the target parts. The materials are discretely stacked layer by layer and processed from bottom to top. Huang Zifan, Ma Yuelong and others analyzed the transmission characteristics according to the forming principle of involute ring gear ball gear in 2015, and put forward the rapid forming scheme of involute ring gear ball gear, as shown in the figure.
This processing method of processing involute ring gear ball gear based on FDM technology decomposes the complex three-dimensional processing into simple two-dimensional combination, gets rid of the limitations of various cutting tools and machine tools, shortens the processing cycle and realizes the rapid processing of ball gear. However, due to the concept of layered manufacturing and stacking of three-dimensional objects, if the curvature of the tooth profile is too large or the inclination angle is large, Through layered stacking, the tooth profile surface will have a large roughness, so the size of the step effect will decrease with the decrease of the inclination angle. Compared with the actual tooth profile and the theoretical tooth profile, the analysis of the experimental data shows that the error is mainly caused by the accumulation of machining error, assembly error and measurement error, That is, the filament of the nozzle has different widths and the material has slight thermal expansion and cold contraction in the process of solidification and contraction. In order to solve the problems caused by the above errors, the researcher proposed a more optimized rapid prototyping technology to process involute ring gear ball gear.
2.2 Metal powder laser sintering technology (SLS)
Metal powder laser sintering technology is also known as SLS selective laser sintering technology. The principle of processing involute ring gear ball gear by SLS process is to draw the three-dimensional model of involute ring gear ball gear by using CAD three-dimensional software, generate the file into STL file format, check, interpolate, display and slice the STL file by data processing software, lay a layer of metal powder material on the base plate of powder bed, compact and preheat it, The computer control system controls the scanning of the laser beam. The metal powder material is sintered under the laser irradiation and bonded with the formed part of the lower layer. After the lower layer is stacked and formed by the computer, the processing of the involute ring gear ball gear is completed. This method has a wide range of materials, can directly make metal products, the sintering route and temperature are easy to control and adjust, the sintering cycle is short, and the accuracy, compactness and mechanical properties of involute ring gear ball gear are improved. The three-dimensional model directly drives the manufacturing of products, and the integration of design and manufacturing provides convenient technical support for product production.