A system, comprising a second coil mechanism configured to correspond to a first coil mechanism, wherein the first coil mechanism comprises a first coil assembly, and the second coil mechanism comprises: a second coil assembly, configured to correspond to the first coil mechanism to transfer power or signal; and a main axis (22-AX1), parallel to a third main body of the second coil assembly; the third main body has a three-dimensional structure, extending along the main axis (22-AX1) and having a tapered structure; a fourth coil assembly is extended along the main axis (22-AX1), and the winding axis of the fourth coil assembly is parallel to the main axis (22-AX1); the fourth coil assembly has a fourth main body, and the fourth main body has a three-dimensional structure extending along the main axis (22-AX1); the fourth main body has a tapered structure tapering toward the third main body, and the third main body has a tapered structure tapering away from the fourth coil assembly; the second coil assembly is extended along the main axis (22-AX1), the winding axis of a fifth main body of a fifth coil assembly is parallel to the main axis (22-AX1); the fifth main body has a three-dimensional structure extending along the main axis (22-AX1); as seen from the main axis (22-AX1), a gap is formed between the third main body and the fifth main body; as seen from a direction perpendicular to the main axis (22-AX1), the third main body does not overlap the fifth main body; wherein the second coil mechanism further comprises a sixth coil assembly, configured to perform a first function, the second coil assembly is configured to perform a second function, the first function is different from the second function, and a sixth main body of the sixth coil assembly has a plate structure; as seen from the direction perpendicular to the main axis (22-AX1), the third main body does not overlap the sixth main body; as seen from the direction perpendicular to the main axis (22-AX1), the third main body (22-23100, the fourth main body, the fifth main body, and the sixth main body do not overlap. a second coil assembly, configured to correspond to the first coil mechanism to transfer power or signal; and a main axis (22-AX1), parallel to a third main body of the second coil assembly; the third main body has a three-dimensional structure, extending along the main axis (22-AX1) and having a tapered structure; a fourth coil assembly is extended along the main axis (22-AX1), and the winding axis of the fourth coil assembly is parallel to the main axis (22-AX1); the fourth coil assembly has a fourth main body, and the fourth main body has a three-dimensional structure extending along the main axis (22-AX1); the fourth main body has a tapered structure tapering toward the third main body, and the third main body has a tapered structure tapering away from the fourth coil assembly; the second coil assembly is extended along the main axis (22-AX1), the winding axis of a fifth main body of a fifth coil assembly is parallel to the main axis (22-AX1); the fifth main body has a three-dimensional structure extending along the main axis (22-AX1); as seen from the main axis (22-AX1), a gap is formed between the third main body and the fifth main body; as seen from a direction perpendicular to the main axis (22-AX1), the third main body does not overlap the fifth main body; wherein the second coil mechanism further comprises a sixth coil assembly, configured to perform a first function, the second coil assembly is configured to perform a second function, the first function is different from the second function, and a sixth main body of the sixth coil assembly has a plate structure; as seen from the direction perpendicular to the main axis (22-AX1), the third main body does not overlap the sixth main body; as seen from the direction perpendicular to the main axis (22-AX1), the third main body (22-23100, the fourth main body, the fifth main body, and the sixth main body do not overlap.