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, sliding pedals, a conical core and a protecting cover, 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 conical core is connected with the shaft sleeve by the connecting shaft, the conical 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 are distributed uniformly and circumferentially in cavities of the flange plate and the chassis, each of bottom surfaces of the eight sliding pedals is received in a corresponding one of the eight T-shaped chutes respectively, so that the sliding pedals can smoothly slide in the chutes highly precisely, the inner side wall of each sliding pedal is a 15-degree inclined plane, and the flange plate is connected with the eight sliding pedals by the eight springs;

• two groups of 15-degree inclined planes which are uniformly and circumferentially distributed at intervals are arranged on side surfaces of the conical core, and the two groups of the inclined planes are arranged in an alternative order, the number of the inclined planes in each group is eight, height difference exists between each two of 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 sliding pedals are in contact with the conical surface of the conical core when the conical core is located at the bottommost position, the servo motor drives the conical core to rotate at an angle of 22.5 degrees by the mounting plate, the shaft sleeve and the connecting shaft, and the sliding pedals which are matched with the inclined planes can be switched between the two groups of the inclined planes of the conical core;
• and when the oil cylinder drives the connecting shaft and the conical core to move in the up-down direction, by cooperation of the inclined planes of the sliding pedals with the inclined planes of the conical core, the eight sliding pedals synchronously move centripetally and centrifugally along the eight T-shaped chutes formed in the cavities of the flange plate and the chassis.