Transmission

A transmission to be contained in a power unit (P) for a saddled vehicle having an internal-combustion engine (E), the transmission comprising:

• driving shafts (31, 32) that receive power from a crankshaft (23) of the internal-combustion engine (E);
• an output shaft (33) that receives the power from the crankshaft (23);
• a gear group (G) that transmits the power from the driving shafts (31, 32) to the output shaft (33);
• a shift gear (66) included in multiple gears of the gear group (G), the shift gear (66) relatively rotatably supported by at least one shaft (67) of the driving shafts (31, 32) and the output shaft (33) and having gear dog teeth (66t);
• a gear switching mechanism (60) having a sleeve (61) and a blocking ring (63), the sleeve (61) supported by the shaft (67) in a movable manner in an axial direction while relative rotation is inhibited, the blocking ring (63) disposed between the shift gear (66) and the sleeve (61), the blocking ring (63) having ring teeth (63t) that are interposed between sleeve teeth (61t) of the sleeve (61) and the gear dog teeth (66t), the sleeve (61) configured to move to make an inner circumferential surface (63a) of the blocking ring (63) come into contact with a protruding cylindrical part (66ss) of the shift gear (66), whereby the sleeve (61) synchronizes with the shift gear (66), the sleeve (61) configured to further move to make the sleeve teeth (61t) come into contact and mesh with the ring teeth (63t) and then make the sleeve teeth (61t) come into contact and mesh with the gear dog teeth (66t), whereby the sleeve (61) engages with the shift gear (66), resulting in establishment of a speed stage;
• and
• a gear shift operation mechanism (70) that makes the sleeve (61) move in the axial direction by applying a pushing force (F) for pushing the sleeve (61) to the shift gear (66), and the pushing force (F) being generated by a driving force of an actuator (72),
• wherein the transmission further comprises:
• an engine speed measuring unit (101) that measures a number (Ne) of rotation of an engine of the internal-combustion engine (E);
• a sleeve position measuring unit (102) that measures a position of the sleeve (61);
• and
• a gear shift control system (100) that controls the gear switching mechanism (60),
• the gear shift control system (100) configured to control the actuator (72) so that the pushing force (F) is controlled to be a constant gearing-phase pushing force (Fg) during a gearing phase, the gearing phase starts a predetermined time before tips of the sleeve teeth (61t) of the sleeve (61) come into collision with tips of the gear dog teeth (66t) of the shift gear (66) and ends when a predetermined time passes after the collision between the sleeve teeth (61t) and the gear dog teeth (66t),
• the gearing-phase pushing force (Fg) is controlled on a basis of a number (Neg) of rotation of the engine in the gearing phase, which is measured at the start of the gearing phase, so as to increase as the number (Neg) of rotation of the engine in the gearing phase increases.