Drug delivery device

A drug delivery device comprising:

• a housing (10);
• a driving mechanism (20) arranged in the housing (10), the driving mechanism (20) comprises an adjusting member (21), a first memory (22) and a second memory (23) cooperating with the first memory (22), the second memory (23) has an initial position and an end position relative to the first memory (22), and the driving mechanism (20) has a adjusting state and a delivering state;
• when the driving mechanism (20) is in the adjusting state, the adjusting member (21) drives the second memory (23) to move between the initial position and the end position;
• when the driving mechanism (20) is in the delivering state, the adjusting member (21), the first memory (22) and the second memory (23) are relatively static;
• a first limiting structure (30) comprising a first limit member (31) and a second limit member (32), one of the first limit member (31) and the second limit member (32) is arranged on the first memory (22), and the other of the first limit member (31) and the second limit member (32) is arranged on the second memory (23);
• the first limit member (31) cooperates with the second limit member (32) to limit the movement of the second memory (23) relative to the first memory (22) when the second memory (23) is at the end position;
• an injection mechanism (40) used for injecting medication;
• a transmission mechanism (50) arranged between the driving mechanism (20) and the injection mechanism (40), the driving mechanism (20) drives the injection mechanism (40) to inject a dose through the transmission mechanism (50).