Design and application of the hottest small taper

Design and application of small taper rotary center

umbrella rotary center, also known as big head center or pipe center, is mainly used to support sleeve parts, which can bear high cutting load, improve workpiece support stiffness and reduce workpiece stress and deformation. "Positioning, clamping and device comprehensive marking example national standard jb/z" has the marking diagram of "positioning and clamping of umbrella shaped center at the head of the bed and umbrella shaped center at the tail of the bed", and the positioning and clamping form of plum blossom center at the head of the bed and umbrella shaped center at the tail of the bed is often used in the processing of the outer circle of the tube blank. The cone angle of the head of these umbrella shaped tips or plum blossom tips is generally 60 ° or 75 °, and a few are 90 °. The advantage of umbrella shaped rotary center with large cone angle is good versatility. One center can adapt to the processing of workpieces with inner hole sizes ranging from tens of millimeters to one or two hundred millimeters. The disadvantage is that the positioning accuracy is low, and the position error of the excircle or end face processed with its positioning is large. In view of the shortcomings of the umbrella shaped rotary center with large taper, the author designed and manufactured a series of small taper Rotary Centers, which have achieved good results through several years of production practice. Now it is introduced as follows

1 small taper rotary center structure

the figure below shows the small taper rotary center, the solid line in the figure is the small taper rotary center structure with the small end size of the cone sleeve less than 30mm, and the double dotted line is the small taper rotary center structure with the small end size of the cone sleeve greater than 30mm. The taper angle of the taper sleeve is generally 30 °. To further improve the positioning accuracy, it can be reduced to 20 ° or even 15 °. The material of the cone sleeve is 9mn2v, and the heat treatment is 60 ~ 64hrc, which makes it have higher hardness and wear resistance and prolong its service life. The material of taper handle is 40Cr, and the heat treatment is 40 ~ 45hrc. When the gap seal is used between the taper handle and the screw cap, the gap shall not be greater than 0.2mm (for the small taper rotary center with d0 greater than 100mm, felt seal should be used). Two single row radial ball bearings with grade: accuracy ensure that the center has high positioning and rotation accuracy and bears radial force; one-way thrust ball bearings with grade e accuracy are used to bear axial load. The tolerance zone of the hole matching the inner hole of the cone sleeve and the bearing is M7: the axial tolerance zone of the mating surface of the cone handle and the single row radial ball bearing is H6, and the axial tolerance zone of the mating surface of the thrust ball bearing is J6

1. Taper sleeve 2 Gland 3, 4 Washer 5 Screw cap 6 Taper handle 7, 13 Screw 8 Paddles 9, 11, 12 Bearing 10 Oil cup 14 Screw plug

structural diagram of small taper turning center

during assembly, the bearing and screw cap hole of the turning center shall be filled with grease. After the bearing clearance is adjusted to be qualified, the screw cap shall be locked with screws. Finally, insert the Morse taper handle into the spindle taper hole of the universal cylindrical grinder, drive the taper sleeve to rotate with the paddle, and fine grind the taper surface of the taper sleeve to ensure the shape and position tolerance and the requirements of size and surface roughness. Taper sleeve plastic is almost used in all aspects of people's life. This method is also used when the conical surface is worn, bruised or deformed

2application

in the processing of 300mm long bushing (the nominal diameter of the inner hole has five specifications of 32, 38, 44, 56 and 70mm, the wall thickness is 5.5 ~ 8 and aligned with the center mm) produced by our series of tubular oil well pumps, followed by the running inspection of the beam of the experimental machine, we use the small taper rotary center to grind the outer circle of the hardened long bushing. The method is as follows: two small taper Rotary Centers are installed in the taper holes of the main shaft and tailstock sleeve of the cylindrical grinder respectively (a paddle should be added to the ones installed on the main shaft), the friction between the periphery of the workpiece hole and the taper sleeve and the paddle should be used to drive the workpiece to rotate, and the workpiece is pressed tightly by the compression spring force of the tailstock of the grinder to grind the cylindrical. It is also Owens Corning's largest use of the market, and the surface roughness of the workpiece reaches Ra0.4 μ m. The roundness is 0.005mm, and the coaxiality of the outer circle to the inner hole is within 0.01mm (excluding the shape error of the workpiece hole). Loading and unloading the workpiece is fast and convenient. Compared with grinding the outer circle with ball mandrel and roller mandrel in the past, it greatly reduces the labor intensity of workers and improves the work efficiency several times, which is highly praised by workers. (end)