| Single-screw compressor is a mechatronics equipment with advanced technology in the compressor industry in the world.It can complete gas compression under pressure balance,with good force balance performance,no clearance volume,large single-capacity capacity and light load.High speed,easy to build fluid power lubrication,low noise,etc.,has been widely used in many fields.At present,the theoretical research and design level of single-screw compressors in the country have reached the world’s advanced level,but the manufacturing process technology and process methods for the engagement of the core components of the compressor have not been able to make major breakthroughs and become a constraint on compression in China.The huge obstacles to the development of the machine industry.For this reason,this article takes the screw rotor of a single-screw compressor of a company as the research object,and in view of the difficult processing,low-precision machining,and poor processing efficiency of the commonly used rotary copying turning machining methods,the current situation at home and abroad is understood.Based on the analysis of the machining process and the use of orthogonal test methods,the research work on the influence factors of rotor machining accuracy was completed:(1)Establish a mathematical model of a new spiral groove side.By studying the machining principle of the screw tooth groove surface,a mathematical model of the tool path is established.According to the relative motion of the tool and the screw,the space enveloping trajectory of the screw spiral surface of the tool is determined,and the side equation of the spiral groove of the secondary enveloping rotor is established.It provides theoretical support for analyzing the influencing factors of rotor machining accuracy.(2)Effect of CNC System on Rotor Machining Accuracy The control accuracy of the numerical control system and the feed positioning accuracy of the turning tool can seriously affect the surface quality of the rotor spiral groove,the distribution of the six spiral grooves of the screw rotor on the rotor surface,and the consistency of the spiral groove machining accuracy.Therefore,the influence of the numerical control system on the machining accuracy of the rotor cannot be ignored.(3)The influence of the distance between the rotor machining tool and the centerline of the rotor on the machining accuracy of the rotor.The distance between the tool and the centerline of the rotor affects the center-to-center distance between the screw rotor and the spider.The accuracy of this distance can not be guaranteed,it will lead to the screw rotor and the star wheel meshing is not smooth,accelerate the wear of the star wheel,in serious cases will cause the meshing vice to get stuck,the motor burned.(4)Effect of Rotor Tool Length on Rotor Machining Accuracy The length of the tool affects the meshing accuracy between the outer surface of each tooth of the star wheel and the bottom of the screw rotor.If the knife length is too long,it will result in poor meshing accuracy,reduced compression efficiency,and reduced compressor performance.At the same time,it will also cause the end of the star wheel to rub against the bottom of the rotor of the screw rotor,which will increase energy consumption.In severe cases,it will cause the star wheel to break.(5)The effect of tool rotation on the machining accuracy of the rotor in six circles.The six-stroke feed of tool rotation affects the roughness and machining efficiency of the screw rotor groove wall,and ultimately affects the wear rate of the tooth side of the star wheel.Through theoretical and experimental analysis and verification:(1)The designed rotor and starwheel meshing subtype line has better hydrodynamic lubrication performance and processing performance,which brings convenience to the processing of the single screw rotor,which is difficult to achieve in the early traditional processing methods.(2)In order to ensure the machining accuracy and surface quality of the rotor,the rotational speed ratio of the screw rotor and the rotary profiling tool controlled by the numerical control system must strictly comply with 11:6;the distance between the center line of the tool and the rotor and the center distance given in the meshing pair drawing should be controlled The dimensions are exactly the same;the tool length of the tool should be controlled under the premise of ensuring the meshing clearance,plus the wear amount of the tool processing process is 0.02-0.03mm;the tool feed amount for the six rotations should be controlled under the conditions of the groove wall roughness,so that the The processing efficiency is maximized and the optimum level is 0.07 mm.(3)Among these factors,the importance of each factor on the machining accuracy is: the control accuracy of the CNC system has the greatest influence,followed by the distance between the rotor machining tool and the centerline of the rotor,and then the tool length and tool rotation of the tool during machining.The amount of feed is after 6 circles.(4)An error analysis was performed on the best production conditions obtained by the test,with an error of 4.21,which was verified by repeated tests.The results are in line with the conclusions.Through experiments,the best production conditions of the distance between the center line of the tool and the rotor,the tool length of the tool and the tool feed for six rotations were obtained.The error analysis was also performed on the best production conditions obtained.The machining precision and processing efficiency of large single-screw rotors have been improved,which has a high guiding significance for improving the manufacturing capability of single-screw compressor screw rotors in China. |
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