An electric power generation controller for use in an aircraft is a controller of an electric power generating apparatus including a manual transmission configured to change speed of rotational power of an aircraft engine, transmit the rotational power to an electric power generator, and switch a gear stage by a friction clutch pressed by an actuator. The electric power generation controller includes a manual transmission control section configured to control the manual transmission. The manual transmission control section includes: a shift command section configured to output a shift signal which switches the gear stage of the manual transmission; and a clutch control section configured to, when switching the gear stage of the manual transmission, control clutch pressure of the actuator such that the friction clutch becomes a half-engaged state.

A drive with an electric motor and transmission connected to the electric motor at a drive shaft. Transmission has gears with different transmission ratios. The transmission performs a shifting process in which a coupling of the drive shaft, driven by the electric motor rotating at a first rotational speed, to the output shaft via a first gear with a first transmission ratio is first released, whereby the drive shaft is no longer rotationally coupled to the output shaft, after which the drive shaft is rotationally coupled to the output shaft via a second gear with a second transmission ratio. An electric synchronizing device is provided to change a rotational speed of the electric motor to a second rotational speed for a duration of the shifting process. The second rotational speed corresponds to the first rotational speed multiplied by a quotient of the second transmission ratio and first transmission ratio, and the drive is designed to produce a releasable rotational coupling between the drive shaft and the output shaft via the second gear by positive engagement. The drive shaft is releasably coupled to the output shaft via a gear by at least one dog engaging a depression in a window extending along a direction of an element coupled to the drive shaft movable relative to an element coupled to the output shaft when not coupled to the drive shaft during a shifting process, so that the dog is movable into the depression through the window.

A method for motion control of a shift sleeve in a stepped gear transmission during a synchronization and gear engagement sequence for avoiding gear teeth interference, wherein the stepped gear transmission includes an axially displaceable shift sleeve arranged on and rotationally secured to a shaft, and a constant mesh gear wheel arranged on and rotatable relative to said shaft.

A method for changing between a multiplicity of discrete transmission ratio stages in a motorcycle gearbox is provided. In response to a shift demand, during the torque-transmitting connection of a drive shaft of the drive machine to a gearbox input shaft, a gear-selection drum of the transmission is rotatable from a first shifting position to an intermediate position which is situated between the first and a second shifting position, before shifting to the second shift position. In the intermediate position, no drive torque can be transmitted from the gearbox input shaft to a gearbox output shaft. During the gear selection drum movement from the first shifting position and the intermediate position, the drum may be rotated to a rest position in which drive torque can be transmitted from the gearbox input shaft to a gearbox output shaft.

A method for synchronizing a first drive element rotatable about an axis of rotation with a second drive element rotating about the axis of rotation at a target speed, of a powertrain of a motor vehicle, in which a synchronizing force is exerted on a synchronizing unit by an actuator. A speed, at which the first drive element rotates about the axis of rotation is adapted by the synchronizing unit to the target speed. The synchronizing force is increased during a first time span, so that the speed approaches the target speed. The synchronizing force is continuously reduced during a second time span following the first time span, before the speed corresponds to the target speed.

The present invention provides a shift control method include: setting a basic target synchronization rotation speed that is a basic target value of the input shaft rotation speed during the shift; determining whether or not an accelerating intention is present when the shift is a downshift with a driving force requirement to the vehicle; when the accelerating intention is present, setting a first target input shaft rotation speed as the target input shaft rotation speed, the first target input shaft rotation speed being obtained by increasingly correcting the basic target synchronization rotation speed; and when the accelerating intention is not present, setting a second target input shaft rotation speed as the target input shaft rotation speed, the second target input shaft rotation speed being obtained by maintaining or decreasingly correcting the basic target synchronization rotation speed.

The present invention relates to a two-stage transmission for an electrically driven vehicle including a dog clutch and a friction clutch, and an object of the present invention is to prevent a torque drop when shifting gears. The two-stage transmission for the electrically driven vehicle includes a planetary gear mechanism (12), a dog clutch (28), a friction clutch (30), an armature (26) to switch between the dog clutch (28) and the friction clutch (30), and an electromagnetic coil (31) to drive the armature (26). In the dog clutch (28) and the friction clutch (30), the coupling relationship among the rotational elements of the planetary gear mechanism (12) is set such that the dog clutch (28) is fastened and the friction clutch (30) is not fastened in speed reduction (the first speed), and the dog clutch (28) is not fastened and the friction clutch (30) is fastened in speed increase (the second speed). To prevent the torque drop when shifting the gears, a ratchet-type one-way clutch (50) is disposed such that a rotational phase position of the ratchet-type one-way clutch (50) is coincident with that of the dog clutch (28). When shifting from the second speed to the first speed, since the rotational phase of the dog clutch (28) is adjusted by the ratchet-type one-way clutch (50), the shifting is instantaneously completed without waiting operation for the phase adjustment, resulting in preventing a transmission shock.

A control method of a transmission of an electric vehicle provided with a transmission having a sleeve gear having an inclined chamfer on a first side of the sleeve gear and a flat chamfer on a second side of the sleeve gear, may include measuring a maximum movable stroke of a sleeve having the sleeve gear by moving the sleeve axially to both sides by a controller; determining a reference range to which the measured maximum stroke pertains from predetermined reference ranges by the controller; and determining and setting a neutral position of the sleeve using a predetermined determination method, depending on the determined reference range by the controller.

Methods and systems for seamlessly transitioning a load between two different actuators each having a different transmission ratio are described herein. A multiple drive, variable transmission ratio (MD-VTR) system includes two drive actuators, each having different reduction ratios, a locking mechanism, and a differential transmission subsystem. In one aspect, a MD-VTR system includes a locking mechanism disposed between a drive actuator and an input port of the differential. The locking mechanism couples the input port of the differential to a stationary reference frame element in a locked state. In an unlocked state, the locking mechanism couples the drive actuator to the input port of the differential. In some embodiments, the locking mechanism includes an actuator to actively transition between the locked and unlocked states. In some other embodiments, the locking mechanism transitions between the locked and unlocked states based on torque applied by the drive actuator.

Methods and system are described for changing a driveline gear range from a lower gear range to a higher gear range. The driveline may include two electric machines and four clutches in a four wheel drive configuration. The methods and systems permit a driveline to change from a lower gear range to a higher gear range in a way that may reduce torque disturbances that may result from gear lash.