Adjustable dumbbell

An adjustable dumbbell, comprising a dumbbell body (1), dumbbell plates (3), and a dumbbell base (2) for placing the dumbbell body (1) and the dumbbell plates (3), the dumbbell body (1) comprising a dumbbell rod assembly (4) and two dumbbell clamp assemblies (5) configured to mount the dumbbell plates (3), wherein the dumbbell rod assembly (4) comprises a shaft center (402) in a prismatic structure and a handle (401) arranged in a middle of the shaft center (402) in a running fit manner;

• the two dumbbell clamp assemblies (5) are fixed to two ends of the shaft center (402), respectively;
• each of the two dumbbell clamp assemblies (5) comprises a limit rack (501) configured to mount the dumbbell plates (3), and a fixing disk (505) and a tail iron plate (504) configured to limit the mounted dumbbell plates (3);
• the fixing disk (505) and the tail iron plate (504) are fixed to two ends of the limit rack (501), respectively;
• an expansion chute (502) is horizontally provided in a position, corresponding to the shaft center (402), of a middle of the limit rack (501);
• the two ends of the shaft center (402) are both sleeved with telescopic sleeves (403) capable of sliding into the two expansion chutes (502) and configured to fix the dumbbell plates (3);
• gear sets (509) are provided in a running fit manner at positions, located inside the two fixing disks (505), of one ends of the two limit racks (501);
• each of the two fixing disks (505) is internally provided with an internal gear ring (508) driven by the handle (401) in a running fit manner;
• the two internal gear rings (508) drive the two telescopic sleeves (403) by the two gear sets (509) respectively to move;
• limit blocks (8) capable of locking rotation of the internal gear rings (508) are arranged at positions, located inside the two fixing disks (505), of the one ends of the two limit racks (501);
• each of the gear sets (509) comprises a master gear (5091) and two driving gears (5093);
• the master gear (5091) is meshed with teeth of an inner ring of the internal gear ring (508);
• two sides of the master gear (5091) are both provided with pinions (5092) in a synchronous running fit manner;
• the two driving gears (5093) are meshed with the two pinions (5092), respectively;
• each of the telescopic sleeves (403) is provided with a tooth space (404);
• and the telescopic sleeve (403) is meshed with the two driving gears (5093) through the tooth space (404).