New type of machine sealing bushing processing method

The new 2020 - machine sealing bushing processing method 08 - 26 Ren Libin ( Powerful shijiazhuang pump industry group co. , LTD. ) With the development of social economy and user on the improvement of safety and environmental protection consciousness, and mechanical seal is finding wider and wider application in the field of pump products, and users in the quality of mechanical seal products, the use of performance requirements also more and more high. To this end, our company development, container type mechanical seal was developed, its characteristic is: products have been through the debugging before they go out, do not require users to do any adjustment, can directly use assembly, so that the container type mechanical seal has a good application prospect. However, due to the container type mechanical seal assembly size restrictions, become compact, complex structure, the requirement of machining accuracy is very high, in order to ensure the parts structure strength and processability as well as the use of the requirements of the medium, mechanical seal parts for more than 90% of all use corrosion resistant stainless steel material, so also brought some difficulties to machining. A shaft sleeve, parts analysis as one of the key components of mechanical seal, both transmission and the effect of friction ring installation, its quality will directly affect the dynamic and static friction pair can satisfy the requirement of the mechanical seal floating high frequency compensation, therefore, its machining quality and machining precision of high and low will directly affect the quality of mechanical seal assembly and service life, and, in turn, affects the entire product promotion and use. Its spare parts pattern is shown in figure 1. Figure 1 collar, processing difficulties analysis given the key role of the parts in the mechanical seal, its machining precision demand is higher, at the same time restricted by their structure, has the following processing difficulty. This piece for 316 l stainless steel material, its features are: (1) material, high plasticity, toughness big chip is not easy to break. Strong adhesion (2) chip, chip cutting process tumor, affect the quality of the machined surface. (3) the material of low thermal conductivity, heat cutting the accumulation in front of the cutting tool knife, the blade from overheat and rapid wear. The size and the cylindrical inner hole is 0. 4 mm coaxial degree requirements. The ring groove seam allowance and inner hole are 0. Slot 4 mm coaxial degree requirements, check the underside of end face and inner hole are 0. 3 mm vertical degree requirements. Ring installation groove surface roughness value reach Ra = 1. 6μ m。 Face in seam allowance without proper tool. Due to the structure, the clamping area is lesser, cylindrical clip left easy cause face inside the seam allowance deformation, and the right end, the contour machining precision is not easy to control, easy to cause hole taper. If the clip right end cylindrical, easy to make the turning of inner hole in common phenomenon of triangle hole. 3, processing method through the above analysis, according to the characteristics of the shaft sleeve, use the following methods to solve the machining problems: 1, the clamping methods using homemade fan extended soft three jaw self centering chuck clamp collar corresponding cylindrical inner hole gap, increasing the fixture and the workpiece, the contact area to solve the inner hole the triangle hole problem in the machining process, at the same time increase the clamping force. 2, cutting tool selection according to the characteristics of stainless steel and the status quo, my company decided to make the cutting tool. Choose YG8 tool machining inner hole and cylindrical. Select a tool Angle larger rake Angle and back Angle ( See figure 2) , open circular groove, reduce the cutting deformation, selecting rational main Angle at the same time, make the chip discharging, the turning tool rod to the chip is not retained inside the hole and cut machining surface. A large Angle and large main rake Angle increased the intensity of cutting tool and the heat dissipation area, to cutting heat loss, reducing the tool wear. Homemade extended chamfered cutter machining end inside the seam allowance size is shown in figure 3. Figure 2 inner hole tool Angle figure 3 chamfer cutter 3, cutting parameters choosing rough turning speed n = 160 r/min, feeding f = 0. 27 ~ 0. 81 mm/r, cutting depth ap = 3 ~ 5 mm; Fine car speed when n = 250 r/min, feeding f = 0. 1 mm/r, cutting depth ap = 0. 1mm。 Four, choose the right end face of coarse car and outer circle and inner hole. Leave allowance for 1 ~ 2 mm. Thick cylindrical big car and left face. Leave allowance for 1 ~ 2 mm. School random car fan soft three jaw self centering chuck clamp large cylindrical, the clamping force is moderate, semi finished inside cylindrical holes, and various sizes of face and mouth. Leave allowance 0. 2 to 0. 3mm。 Then appropriate claw, cylindrical hole inside the car, and face, check to the design requirements. School extended run, random car fan soft three jaw self centering chuck, central shaft sleeve non-critical parts, car big cylindrical and the left end face and inner hole groove to requirements. Five, technology analysis processing in coarse and fine car process helps to improve the machining efficiency, suitable for mass production. School semi-finishing and finish machining, the car fan soft three jaw self centering chuck clamp large cylindrical, appropriate loose claw when finishing, semi-finishing release stress produces in the process, the clamping with cylindrical and the left end face positioning, clamping, processed into cylindrical right end all sizes, in the hole and face slot size, not only ensure the precision of relative position degrees, and ensure the reliability of the clamping and machining system rigidity; Also extended fan soft axis of three jaw self centering chuck middle part, has the following functions: (1) increasing clamping area, to prevent the deformation of inner hole. (2) to avoid the task of the workpiece shape key parts, to ensure the good appearance quality. (3) a clamping, ensure the position precision machining. Six, test results to test the artifacts, as shown in table. Test results ( Unit: mm) Source: the metal processing ( Cold working) 'In 2018