The three-row full-roller bearing without outer ring has many segments, large size, high quality, low device precision during processing, large quenching deformation of the whole ring, large stress at the joint, and the radial and circumferential gaps are not easy to adjust. There are many times of grinding the raceway during the clearance, and the blade of the ancient high-speed steel material is easy to wear. Propose improvement measures: increase the special mold during processing and splicing; adopt segmental and faceted quenching, and increase the shaping process after quenching; plan radial positioning fixtures to adjust radial clearance, plan tangential positioning fixtures to adjust the circumferential direction gap; The inner and outer ring axial raceway dimensions required to be machined are calculated by the clearance calculation; the coated carbide tool is used for soft turning, and the cubic boron nitride (CBN) tool is used for hard turning to realize grinding by turning. The identified process route meets the technical requirements required for bearing processing. With the maturity of offshore equipment technology, large-scale cranes in the offshore industry have been developed to super large size and super tonnage, and the diameter of the slewing bearing with them is more than 10 m. The layout of the slewing bearing of this diameter section is mostly split type, which has the advantage of being convenient for transportation, storage and disassembly, and the disadvantage is that it requires repeated disassembly and splicing, the processing technology is complex, and the processing accuracy is difficult to guarantee, so it is necessary to determine the appropriate processing technology . Difficulties in processing full-roller bearings without outer ring 1) The diameter of the bearing exceeds the processing limitations of the machine tool table. 2) Dividing the code word on the thrust raceway will form a certain angle with the element line of the roller, so that the roller can pass the code word. In order to ensure that the gear strength is less affected, the outer ring gear is cut in the middle of the bottom of the tooth groove, which increases the difficulty of milling the continuous surface and splicing the whole circle. 3) The diameter of the split bearing is large. During the processing, the split section falls and skews due to its own weight. The flatness and skewness of the two end surfaces and the axial raceway are large. The roundness and cylindricity of the radial raceway exceed the technological requirements. Torsional accuracy cannot meet the requirements. 4) The total length of the quenching surface of the outer ring gear is 490 mm, which is a large-section raceway quenching. When the whole circle is quenched, irregular deformation will occur in the sections, which cannot be spliced ​​into a full circle after deformation, which affects the subsequent processing. After the whole circle is quenched, the stress at the seam is large, and the ferrule will be disengaged from the seam. The size of the whole circle is large, and the quenching machine tool is difficult to reverse. 2 rows of continuous holes are planned at the bottom of the square box, which are connected to the machine table through bolts. The claws clamp the tire and fix it with a pressure plate. The inner ring is placed on the tire, the long baffle is pressed against the outer diameter surface, and the pressure plate is pressed against the end face of the inner ring. The tire and inner ring are positioned axially and radially, and the number of fixed points is 3 times the number of bearing segments to prevent translation during parts processing. The splicing of a full-roller bearing without an outer ring will affect the machining accuracy of the bearing, so it is necessary to ensure that the outer ring gear is split in the middle of the bottom of the tooth slot. In terms of technology, the tooth shape of the product and the continuous surface subdivision line of fine milling are selected first, and the axial and circumferential fitting surfaces are processed on the CNC gantry milling machine. Through program setting, pre-simulation and adjustment of the length of each arc and the angle and size of the two connecting surfaces, the connecting surfaces are repeatedly developed to ensure continuous accuracy, and the numbering will be paired in sequence after continuous rounding. Split bearings need to be hoisted, spliced, and disassembled repeatedly during processing. In order to ensure the continuous accuracy of the product, small-sized process taper holes are used in the previous process. Continue processing after positioning each continuous point by taper pin. The positioning taper pin holes are processed into reamed bolt holes during final processing to ensure the continued reliability of the parts. When adjusting the radial clearance, place the fixture on the end face of the ferrule, and the screw is pressed against the inner and outer diameter surfaces of the bearing, and is adjusted by the screw. When adjusting the clearance in the circumferential direction, place the rib hole locating pin and the smooth hole locating pin in the two mounting holes at the continuous seam, respectively, and adjust them by screw tightening. By calculating the axial raceway size of the inner and outer rings to be processed by the axial clearance, the number of raceway grinding can be reduced, thereby reducing the number of hoisting and splicing, and improving the processing efficiency. The split bearing is spliced ​​in sections, and each section of the outer ring gear will fall and skew due to its own weight, and the ordinary three-point measurement of the axial clearance is no longer applicable. The axial clearance measurement is shown in Figure 13. The dotted line and the solid line are the actual position and theoretical position of the bearing after assembly. The position of the jack and the dial indicator will both affect the axial clearance. The measured value of point A is larger than that of point B, and the value of point B is closer to the actual clearance. A single point is used to measure the axial clearance. The position of the jack and the dial indicator is close to the inner ring of the bearing. One point is taken at the middle part of each section and at the continuous seam, for a total of 12 points or more, and the balance value is taken as the measured axis. to clearance.
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