Foldable and collapsible module, chassis and stroller

A foldable and collapsible module, comprising:

• a first support rod (100) and a second support rod (200), wherein an extension direction of the first support rod (100) and an extension direction of the second support rod (200) are arranged in parallel, and a length between the first support rod (100) and the second support rod (200) is adjustable;
• along the axial direction of the first support rod (100), the total length of the first support rod (100) and the second support rod (200) is adjustable;
• a first trigger portion (101) arranged on the second support rod (200);
• a second trigger portion (215) arranged on the first support rod (100);
• two wheels (300), wherein the two wheels (300) are arranged on a first end of the first support rod (100) and a first end of the second support rod (200), respectively;
• a first reversing portion (102) arranged on the first support rod (100), wherein the first trigger portion (101) and the first reversing portion (102) are in transmission connection;
• and a second reversing portion (201) arranged on the second support rod (200), wherein the second trigger portion (215) and the second reversing portion (201) are in transmission connection, and the first reversing portion (102) and the second reversing portion (201) are both connected to the corresponding wheels (300);
• as the length between the first support rod (100) and the second support rod (200) decreases, the first trigger portion (101) acts on the first reversing portion (102), and the second trigger portion (215) acts on the second reversing portion (201), such that the first reversing portion (102) and the second reversing portion (201) operate correspondingly, to switch the wheels (300) from an usage state to a collapsed state;
• and
• as the length between the first support rod (100) and the second support rod (200) increases, the first trigger portion (101) acts on the first reversing portion (102), and the second trigger portion (215) acts on the second reversing portion (201), such that the first reversing portion (102) and the second reversing portion (201) operate correspondingly, to switch the wheels (300) from the collapsed state to the usage state.