Hard alloy combined roller locking device

The invention discloses a hard alloy combined roller locking device which comprises a roller shaft and at least one roller ring arranged on the outer side of the roller shaft in a sleeving mode, distance rings are arranged on the two adjacent sides of every two adjacent roller rings, the linear expansion coefficient of the roller shaft is A, the expansion coefficient of the roller rings is B, and the expansion coefficient A of the roller shaft is larger than the expansion coefficient B of the roller rings; and the roller shaft and the roller rings are in interference fit through thermal expansion, one end of the roller shaft is provided with a baffle ring used for blocking the roller rings, the other end of the roller shaft is provided with a locking nut, the locking nut is in tight pressing contact with the end face of the roller ring on the rightmost side, and the roller shaft is in threaded connection with the locking nut. The hard alloy combined roller locking device is designed aiming at defects of exist