A vehicle transmission structure of an embodiment includes a shift drum which rotates in accordance with a shift operation; a bearing member which rotatably supports the shift drum with respect to a transmission case; a set member which positions the bearing member; a shift fork shaft supported by the transmission case; and a shift fork supported by the shift fork shaft to be movable in an axial direction. An end portion of the shift fork shaft is movably fitted to an insertion hole provided in the transmission case, a cap is provided at an end portion of the shift fork shaft, a first gap is provided between an end surface of the insertion hole and the cap, the set member is disposed at a position overlapping the insertion hole when viewed in the axial direction, and a second gap is provided between an end surface of the insertion hole and the set member.

An in-case oil passage extending in an axial direction above a plurality of gears is formed inside an outer peripheral wall portion of the accommodating case. The in-case oil passage includes an in-case oil passage opening portion which opens from the cover wall portion to the one end side in the axial direction. The cover wall portion is provided with an oil guide member at a position where at least a part of the cover wall portion overlaps the in-case oil passage opening portion when viewed from the one end side in the axial direction, the oil guide member guiding oil discharged from the in-case oil passage opening portion to the oil collecting portion of the oil collecting pocket.

A hybrid vehicle includes: a crankcase having a main chamber formed in a case body and accommodating at least a crankshaft, an input shaft, an output shaft, and a gear train, the crankcase further having a subsidiary chamber formed between the case body and a cover and accommodating at least a main clutch; a rotary member disposed in the subsidiary chamber so as to be capable of power transmission to the input shaft; and a power transmission member that transmits drive power from a drive motor to the rotary member.

A straddle vehicle includes: a shift drum that makes a shift change of a transmission including a plurality of gear trains; a transmission case enclosing the shift drum, the transmission case including a side wall portion provided with an insertion hole into which an end portion of the shift drum is inserted; and an actuator unit secured to an outer surface of the side wall portion, the actuator unit including a drive shaft that outputs drive power to rotate the shift drum, the drive shaft having the same rotational axis as the shift drum and being connected to the shift drum on the rotational axis.

A straddle vehicle includes: a prime mover; a hydraulically actuated main clutch disposed in a power transmission route between the prime mover and a drive wheel; an oil control valve unit that controls flow of a hydraulic oil supplied to the main clutch; and a power unit case including a case body and a cover removably mounted on the case body, the power unit case accommodating at least the main clutch. The oil control valve unit is secured to the case body.

A hybrid power assembly and an all-terrain vehicle are provided. The hybrid power assembly includes an engine and a motor. The engine includes a crankshaft and a crankcase, the crankshaft is mounted in the crankcase, the crankcase includes a motor mounting cap, and a first end of the crankshaft extends out of the motor mounting cap. The motor includes a motor housing, a cap of the motor, a stator, and a rotor. The motor housing is mounted between the motor mounting cap and the cap of the motor, the stator is fixed in the motor housing, the rotor is arranged on the inner circwnference of the stator and is rotatable relative to the stator, and the rotor is connected to the first end of the crankshaft.

A power unit includes: a crankcase which accommodates a crankshaft and a main shaft arranged in parallel to each other; a crank side cover which covers one end portion of the crankshaft from the outside in an axial direction of the crankshaft; a primary driven gear which is provided in the main shaft and meshes with a primary drive gear of the crankshaft; a clutch provided at one end portion of the main shaft; and a clutch cover which covers the clutch from the outside in an axial direction of the main shaft and is fastened and fixed to a packing surface provided on the crankcase to surround the clutch, wherein the primary driven gear and the packing surface overlap in a virtual straight line when viewed from the axial direction of the main shaft.

An off-highway recreational includes a frame, a prime mover, a transmission, an intermediate shaft and a main shaft. The transmission is mechanically coupled to receive power from the prime mover and to provide mechanical power at a transaxle output shaft. The intermediate drive shaft is mechanically coupled to the transaxle output shaft, wherein the intermediate drive shaft has a first diameter. The main drive shaft is mechanically coupled to the intermediate drive shaft, wherein the main drive shaft has a second diameter that is greater than the first diameter.

An off-highway recreational includes a frame, a prime mover, a transmission, an intermediate shaft and a main shaft. The transmission is mechanically coupled to receive power from the prime mover and to provide mechanical power at a transaxle output shaft. The intermediate drive shaft is mechanically coupled to the transaxle output shaft, wherein the intermediate drive shaft has a first diameter. The main drive shaft is mechanically coupled to the intermediate drive shaft, wherein the main drive shaft has a second diameter that is greater than the first diameter.

An off-highway recreational includes a frame, a prime mover, a transmission, an intermediate shaft and a main shaft. The transmission is mechanically coupled to receive power from the prime mover and to provide mechanical power at a transaxle output shaft. The intermediate drive shaft is mechanically coupled to the transaxle output shaft, wherein the intermediate drive shaft has a first diameter. The main drive shaft is mechanically coupled to the intermediate drive shaft, wherein the main drive shaft has a second diameter that is greater than the first diameter.