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 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 constant mesh type transmission for a straddled vehicle includes an input shaft; a plurality of drive gears; an output shaft; a plurality of driven gears; and a gear stage setting mechanism, including a ratchet mechanism. The ratchet mechanism includes a n-th speed accelerating pawl, a n-th speed decelerating pawl, a (n+1)-th speed accelerating pawl, a (n+1)-th speed decelerating pawl, a rotary cam, and a plurality of sliders. The rotary cam has a plurality of cam portions on an outer peripheral surface thereof which position the respective guide object parts such that the plurality of sliders raise an accelerating pawl and a decelerating pawl corresponding to a selected gear stage and lower an accelerating pawl and a decelerating pawl corresponding to a non-selected gear stage.

A constant-mesh type transmission for straddled vehicle with a ratchet mechanism is configured to be mounted on a straddled vehicle and has five or more gear stages in addition to a neutral position. The transmission includes an input shaft; five or more drive gears; an output shaft; an odd-numbered stage hub and an even-numbered stage hub; a plurality of odd-numbered stage driven gears; a plurality of even-numbered stage driven gears; a dog engagement mechanism; and a ratchet mechanism. The ratchet mechanism has an odd-numbered stage accelerating pawl, an odd-numbered stage decelerating pawl, an even-numbered stage accelerating pawl, an even-numbered stage decelerating pawl, and a ratchet control mechanism.

A lubrication system of a power assembly of an electric scooter includes a case duct and a bearing seat duct formed in a case of the power assembly, and a driven gear shaft duct formed in a driven gear shaft of a driven gear. Lubricant flows to the case duct, the driven gear shaft duct, a driven gear bearing seat in the case, the bearing seat duct, a driving bearing seat in the case in sequence. The lubrication system has a short flowing distance of the lubricant to enhance the effects of lubrication and reducing temperature.

A transmission case 210 supports a shift shaft 222 that constitutes a part of a speed change operation mechanism 220, and which receives an operating input and transmits a speed change motion of a transmission 201. A part of a transmission holder 162M in which part the shift shaft 222 is disposed includes a shaft insertion opening portion 162g that the shift shaft 222 is disposed so as to pass through.

A transmission and drive system comprises an input end connected to a driving device, an output end connected to a rear wheel, a gear transmission mechanism and a belt driven transmission mechanism. A unidirectional transmission mechanism is connected to the rear wheel with the unidirectional transmission mechanism driving the rear wheel. The transmission provides power output by the driving device, transmits power to the pulley transmission mechanism by the gear transmission mechanism, and the pulley transmission mechanism drives the rear wheel to rotate the unidirectional transmission mechanism, such that the vehicle moves forward. Noise dampening plates are provided to reduce noise emanating from the transmission. In addition, a belt tensioning system is provided to maintain consistent tension on the belt.

A continuously variable transmission housing including an inner cover and an outer cover that define an interior chamber that is structured and operable to enclose a continuously variable transmission primary pulley, secondary pulley and pulley belt. The housing includes a duct panel mounted to the inner cover such that when the primary pulley is disposed within the interior chamber, the duct panel is disposed between an outer face of the primary pulley and the inner cover. An air duct is defined between the inner cover and the duct panel, wherein the air duct is fluidly connected to ambient air from an ambient environment external to the housing. The duct panel forms at least a portion of an ambient air inlet of the housing and includes a center opening that structured and operable to allow the ambient air to be drawn through the air duct and into the housing interior chamber.

Provided is a vehicle speed-change system including the following: a transmission positioned to the rear of a crank shaft of an engine; a transmission case that retains the transmission; a shift mechanism that has a shift cam which performs a speed-change operation of the transmission; and a shift actuator that operates the shift cam. The transmission includes a counter shaft positioned to the rear of the crank shaft, and a drive shaft to which rotation of the counter shaft is transmitted. The shift cam is positioned further to the rear than the counter shaft, and the shift actuator is arranged in a rear portion of the transmission case and to the rear of the shift cam.

A drive unit for a straddled vehicle includes an engine main body unit, a transmission unit, and a shared lubrication oil supply mechanism. The shared lubrication oil supply mechanism includes a first booster pump which pressurizes the shared lubrication oil lubricating both the engine main body unit and the transmission unit and a second booster pump which pressurizes at least part of the shared lubrication oil which has been pressurized by the first booster pump and which is in a positive pressure condition.