Abstract: A lock pin-type automobile synchronizer includes a higher gear conical ring (1) and a lower gear conical ring (4) which are arranged at the sides of a sliding gear sleeve (3). A higher gear lock pin (2) is fixed to one side of the higher gear conical ring (1). A lower gear lock pin (5, 6) is fixed to one side of the lower gear conical ring (4). A pin hole corresponding to the higher gear (2) lock pin and the lower gear lock pin (5, 6) is arranged on the sliding gear sleeve (3). The number of lower gear lock pins (5, 6) is higher than the number of higher gear lock pins (2).

Abstract: A lock pin-type automobile synchronizer includes a higher gear conical ring (1) and a lower gear conical ring (4) which are arranged at the sides of a sliding gear sleeve (3). A higher gear lock pin (2) is fixed to one side of the higher gear conical ring (1). A lower gear lock pin (5, 6) is fixed to one side of the lower gear conical ring (4). A pin hole corresponding to the higher gear (2) lock pin and the lower gear lock pin (5, 6) is arranged on the sliding gear sleeve (3). The number of lower gear lock pins (5, 6) is higher than the number of higher gear lock pins (2).

Abstract: A multi-speed compound vehicular transmission having an auxiliary section with three countershafts, including: a main section; and an auxiliary section, wherein the main section includes an input shaft, an output shaft, a synchronizer and two countershafts symmetrically arranged on both sides of the output shaft; the auxiliary section includes an auxiliary section main shaft and a synchronizer; wherein a reduction gear is arranged on the main shaft, three countershafts are distributed with equal distance around the main shaft, and an output end of the main shaft of auxiliary section is connected to a flange.