Large-stroke tensioning device in wheel machining process

A large-stroke tensioning device in a wheel machining process, comprising a base, a servo motor, a mounting plate, a connecting plate, a shaft sleeve, an oil cylinder, a gland, bearings, a connecting shaft, a chassis, positioning pins, a flange plate, springs, expanding sections, an expanding core and a protector, wherein the mounting plate, the gland and the chassis are fixed on the base, the servo motor is mounted on the mounting plate, the shaft sleeve is mounted on the base by the two rows of bearings and the gland, the oil cylinder is fixed in the shaft sleeve, an output end of the oil cylinder is fixed to the connecting shaft, the servo motor is connected with the shaft sleeve by the connecting plate, the expanding core is connected with the shaft sleeve by the connecting shaft, the expanding core, the connecting shaft and the shaft sleeve are locked in the peripheral direction and do not rotate relatively, the connecting shaft and the shaft sleeve can relatively move in the axial direction, the flange plate is fixed on the chassis, eight T-shaped chutes which are distributed uniformly are formed in cavities of the flange plate and the chassis, bottom surfaces of the eight expanding sections are in one-to-one correspondence to the eight T-shaped chutes respectively, the expanding sections can smoothly slide in the chutes highly precisely, the inner side wall of each expanding section is a 15-degree inclined plane, and the flange plate is connected with the eight expanding sections by the eight springs two groups of 15-degree inclined planes and inclined planes which are uniformly distributed at intervals are arranged on side surfaces of the expanding core, the number of the inclined planes in each group is eight, height difference exists between each two inclined planes, side walls of the upper ends of the two groups of inclined planes are joined at a conical surface, under the combined action of the tension of the oil cylinder and the elasticity of the springs, side walls of the expanding sections are in contact with the conical surface of the expanding core when the expanding core is located at the bottommost position, the servo motor drives the expanding core to rotate at an angle of 22.5 degrees by the mounting plate, the shaft sleeve and the connecting shaft, and the expanding sections which are matched with the inclined planes can be switched between the inclined planes and the inclined planes of the expanding core;

• and the oil cylinder drives the connecting shaft and the expanding core to move in the up-down direction, and the expanding sections are matched with the inclined planes of the expanding core, so that the eight expanding sections perform centripetal motion and centrifugal motion synchronously along the eight T-shaped chutes formed in the cavities of the flange plate and the chassis.