A gear shift control system controls an actuator so that a pushing force will be a constant gearing-phase pushing force, during a gearing phase. The gear shift control system performs control on the basis of the number of rotation of the engine in the gearing phase, which is measured at the start of the gearing phase, so that the constant gearing-phase pushing force will increase as a number of rotation of the engine in the gearing phase increases. Thus, the hitting sound due to collision between the sleeve and the shift gear in shifting gears is reduced.

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.

Methods and system are described for changing a gear ratio of an axle gearbox that does not include friction clutches and that may or may not include synchronizers. The axle gearbox may receive propulsive force via an electric machine. The methods and systems permit the axle gearbox to be shifted from a high gear range to a low gear range while a vehicle that includes the axle gearbox is moving.

A first slider and a fifth-speed driving gear are arranged along an axial direction on a driving shaft. A shift fork has an end located in a guide groove of a shift drum, and another end connected to the first slider. In gear-shifting to a fifth speed, the first slider moves on the driving shaft so that a plurality of fifth-speed dog projections and a plurality of fifth-speed dog recesses mesh with each other. At least four of the plurality of fifth-speed dog projections and at least four of the plurality of fifth-speed dog recesses mesh within a range of 90 degrees at one side in the circumferential direction of the fifth-speed driving gear and a range of 90 degrees at another side in the circumferential direction of the fifth-speed driving gear with respect to a reference line.

An gear case assembly for a watercraft propulsion system has a gear case housing, a driveshaft with a partially threaded bore defined in an end thereof, and a propeller shaft. The propeller shaft and the driveshaft are angled relative to each other. A bevel gear is mounted to the propeller shaft. A pinion mounted to the end of the driveshaft. The pinion meshes with the bevel gear. The pinion defines a central aperture. A fastener is disposed at least in part in the central aperture of the pinion. The fastener fastens the pinion to the end of the driveshaft. The fastener has a head and a shank. The shank is at least partially threaded. The shank extends into the bore of the driveshaft. An outboard motor having the gear case assembly is also disclosed.

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.

The disclosure relates to a method of controlling a dog clutch by a DC motor configured to move the dog clutch via an actuator arm). The dog clutch including at least one gear having one or more dogs configured to engage one or more dogs of a sliding sleeve). The method includes supplying the DC motor with a pulse width modulated voltage having a duty cycle which is provided by a control algorithm). The control algorithm includes a trajectory planner generating a desired position of the actuator arm based on a 4.sup.th order trajectory planning algorithm and a motion controller based on the sliding mode theory for tracking the desired arm position.

A control system for a power transmission unit configured to shift an operating mode smoothly by manipulating engagement devices, and to simplify a structure of the power transmission unit. The control system is configured to reduce a speed difference between an axially stationary engagement element and a reciprocatable engagement element of a second engagement device when shifting from a first continuously variable mode to a second continuously variable mode by engaging the second engagement device. After the second engagement device has been engaged completely, a first engagement device is disengaged.

A motor vehicle includes at least two drive motors, an automatic gearbox, and an electronic control unit, which, during a gear ratio adjustment between an engagement and a loading of a shift element, causes the shift element to be loaded with a predefined torque gradient at a first point in time at which at least one tooth-to-tooth position exists, up to a second point in time, cause the predefined torque to be limited to a maximum permissible torque during a predefined waiting period from the second point in time up to a third point in time, and cause the shift element to be further loaded with the previously predefined torque gradient after the waiting period or when the engaged state is detected.

A transmission is subject to gear shift management that provides for shifting gears in a controlled manner in order to provide for a simplification of part and reduction in system complexity. In particular, a range synchronizer component can be replaced with a simplified range jaw clutch, without incurring a requirement for an installation of other components such as a motor generator or starter-generator.