Under the condition that the rotation speed of a first rotating shaft is higher than that of a second rotating shaft, supported portions go through right-handed helical flutes to perform an engaging operation. Under the condition that the rotation speed of the first rotating shaft is lower than that of the second rotating shaft, the supported portions go through left-handed helical flutes to perform the engaging operation. In a releasing operation, the supported portions go through the right-handed helical flutes to release a clutch mechanism under the condition that the rotation speed of the first rotating shaft is lower than that of the second rotating shaft, and the supported portions go through the left-handed helical flutes to release the clutch mechanism under the condition that the rotation speed of the first rotating shaft is higher than that of the second rotating shaft.

Under the condition that the rotation speed of a first rotating shaft is higher than that of a second rotating shaft, supported portions go through right-handed helical flutes to perform an engaging operation. Under the condition that the rotation speed of the first rotating shaft is lower than that of the second rotating shaft, the supported portions go through left-handed helical flutes to perform the engaging operation. In a releasing operation, the supported portions go through the right-handed helical flutes to release a clutch mechanism under the condition that the rotation speed of the first rotating shaft is lower than that of the second rotating shaft, and the supported portions go through the left-handed helical flutes to release the clutch mechanism under the condition that the rotation speed of the first rotating shaft is higher than that of the second rotating shaft.

A portable information handling system rotationally couples housing portions with a variable torque hinge having a first axle that rotates with a first housing portion, a second axle that rotates with a second housing portion and a synchronizing gear assembly that translates rotation between the first and second axles. Variable torque is applied by selectively engaging and disengaging a coupler gear with the synchronizing gear assembly to apply and remove an increased torque that resists housing rotation. In one embodiment, the coupler gear is an idler gear of the synchronizing gear mechanism that selectively applies and removes an increase torque of the second axle to the first axle. The coupler gear slides in response to an actuator, such as an electro-permanent magnet acting on a ferromagnetic material with high and low magnetic attraction states.

A portable information handling system rotationally couples housing portions with a variable torque hinge having a first axle that rotates with a first housing portion, a second axle that rotates with a second housing portion and a synchronizing gear assembly that translates rotation between the first and second axles. Variable torque is applied by selectively engaging and disengaging a coupler gear with the synchronizing gear assembly to apply and remove an increased torque that resists housing rotation. In one embodiment, the coupler gear is an idler gear of the synchronizing gear mechanism that selectively applies and removes an increase torque of the second axle to the first axle. The coupler gear slides in response to an actuator, such as an electro-permanent magnet acting on a ferromagnetic material with high and low magnetic attraction states.

Transmission systems, disconnect mechanisms, and methods of assembling disconnect mechanisms are envisioned. A disconnect mechanism is adapted to selectively decouple a driving device from a driven device. The disconnect mechanism includes a lever, an inner shaft, an outer shaft, and a housing. The inner shaft is coupled to the lever, the outer shaft is coupled to the inner shaft, and the housing at least partially houses the inner shaft and the outer shaft.

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 gear transmission having a speed changing section includes a speed changing gear for setting a speed stage and a shift gear slidably mounted on a rotation support shaft and operated to engage and disengage with the speed changing gear, the speed changing section configured to speed-change inputted power and to output the resultant power via the rotation support shaft. An arrangement is provided for facilitating engagement of the shift gear with the speed changing gear even when respective end faces of the shift gear and the speed changing gear hit each other. A transmission mechanism (20B) is provided for outputting power of a rotation support shaft (24) to a traveling device. The transmission mechanism (20B) has a transmission flexibility portion (80) which allows free rotation of the rotation support shaft (24) by a set rotation angle.

A gear transmission having a speed changing section includes a speed changing gear for setting a speed stage and a shift gear slidably mounted on a rotation support shaft and operated to engage and disengage with the speed changing gear, the speed changing section configured to speed-change inputted power and to output the resultant power via the rotation support shaft. An arrangement is provided for facilitating engagement of the shift gear with the speed changing gear even when respective end faces of the shift gear and the speed changing gear hit each other. A transmission mechanism (20B) is provided for outputting power of a rotation support shaft (24) to a traveling device. The transmission mechanism (20B) has a transmission flexibility portion (80) which allows free rotation of the rotation support shaft (24) by a set rotation angle.

A vehicle power unit has a transmission apparatus including a transmission, and a transmission actuating mechanism including a speed reduction gear train having multiple speed reduction stages for transmitting power from a drive gear on a drive shaft of a shift motor to a driven gear on a drum turning shaft of a shift drum. The speed reduction gear train has a speed reduction ratio ranging from 23 to 45, and the shift motor is a DC electric motor that produces a pulsating cogging torque having a maximum value ranging from 0.04 to 0.07 Nm. The vehicle power unit enables the transmission actuating mechanism to be made up of a reduced number of parts and to be simple in structure, making the transmission apparatus small in size, and ensures quicker and smoother gear changes with an electric motor.

A gear transmission having a speed changing section includes a speed changing gear for setting a speed stage and a shift gear slidably mounted on a rotation support shaft and operated to engage and disengage with the speed changing gear, the speed changing section configured to speed-change inputted power and to output the resultant power via the rotation support shaft. An arrangement is provided for facilitating engagement of the shift gear with the speed changing gear even when respective end faces of the shift gear and the speed changing gear hit each other. A transmission mechanism (20B) is provided for outputting power of a rotation support shaft (24) to a traveling device. The transmission mechanism (20B) has a transmission flexibility portion (80) which allows free rotation of the rotation support shaft (24) by a set rotation angle.