A powertrain comprising a transmission (2), a first electric motor (4a) and a second electric motor (4b), the transmission having an input shaft (1) to which a source of mechanical power may be connected, an output shaft (6) and a gear assembly providing at least two different gear ratios that may be selected for transfer of mechanical power from the input shaft (1) to the output shaft (6), the first electric motor (4a) is connected to the input shaft (1), such that torque and rotation may be transferred between the first electric motor and the input shaft, and the second electric motor (4b) is connected to the input shaft (1) via a first clutch (5a), such that torque and rotation may be transferred between the second electric motor (4b) and the input shaft (1), and connected to the output shaft (6) via a second clutch (5b), such that torque and rotation may be transferred between the second electric motor (4b) and the output shaft (6), wherein the first electric motor (4a) is connected to the second electric motor (4b) via the first clutch (5a).

A method for controlling an electric oil pump (EOP) of a torque assist automated manual transmission (AMT) using a multi-plate wet clutch and a dry clutch, may include correcting an EOP operating line on a shifting pattern graph such that the EOP operates prior to up-shifting from a first gear to a second gear while driving in the first gear.

The present invention relates to a two-speed transmission for an electric driving vehicle and the two-speed transmission for an electric vehicle has only one actuator. The transmission comprises a planetary gear mechanism (12), an elastic body (44), an armature (26) to integrally rotate with an input axis, an electromagnetic coil (46) and a multi-plate friction clutch (30). A ring gear (20) is fixed to a housing. The armature (26) comprises clutch projection portions (26-1). A dog clutch is constituted by the clutch projection portions (26-1) and recess portions (18-2) of a sun gear (18). When the electromagnetic coil (46) is not electrically energized, the dog clutch is engaged. The rotation of the input axis is reduced and is transmitted to an output axis via the sun gear (18) and a carrier (16). When the electromagnetic coil (46) is electrically energized, the armature (26) is displaced against elastic force, the dog clutch becomes a non-engaging state, a multi-plate friction clutch (30) becomes an engaging state by pressing flange portions (26-4) of the armature (26) and the rotation of the input axis is transmitted to the output axis with a one-to-one relationship. The transmission can comprise a one-way clutch to prevent torque interruption when switching the gear ratio.

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 method to control the execution of a shift to a lower gear with a released accelerator pedal in a drivetrain provided with a dual-clutch, servo-assisted transmission; the following steps are provided: opening, in a first instant, an outgoing clutch; closing, in the first instant, an incoming clutch; completing the opening of the outgoing clutch with a first linear ramp in a second instant; synchronizing, between the second instant and a third instant, a rotation speed of the internal combustion engine with a rotation speed of the incoming clutch; closing of the incoming clutch with a second linear ramp starting from a fourth instant, which is prior to or coincides with the second instant; completing the closing of the incoming clutch in a fifth instant, which coincides with or is subsequent to the second instant; and activating the internal combustion engine so as to generate a torque between the fourth instant and the third instant.

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.

The present invention provides a powertrain comprising a transmission (2), a first electric motor (4a) and a second electric motor (4b), wherein the transmission comprises an input shaft (1) to which a source of mechanical power may be connected, an output shaft (6) and a gear assembly providing at least two different gear ratios that may be selected for transfer of mechanical power from the input shaft (1) to the output shaft (6), the first electric motor (4a) is connected to the input shaft (1), such that torque and rotation may be transferred between the first electric motor and the input shaft, and the second electric motor (4b) is connected to the input shaft (1) via a first clutch (5a), such that torque and rotation may be transferred between the second electric motor (4b) and the input shaft (1), and connected to the output shaft (6) via a second clutch (5b), such that torque and rotation may be transferred between the second electric motor (4b) and the output shaft (6), wherein the first electric motor (4a) is connected to the second electric motor (4b) via the first clutch (5a).

A method to control the execution of a shift to a lower gear with a released accelerator pedal in a drivetrain provided with a dual-clutch, servo-assisted transmission; the following steps ate provided: opening, in a first instant, an outgoing clutch; closing, in the first instant, an incoming clutch; completing the opening of the outgoing clutch by means of a first linear ramp in a second instant; synchronizing, between the second instant and a third instant, a rotation speed of the internal combustion engine with a rotation speed of the incoming clutch; closing of the incoming clutch by means of a second linear ramp starting from a fourth instant, which is prior to or coincides with the second instant; completing the closing of the incoming clutch in a fifth instant, which coincides with or is subsequent to the second instant; and activating the internal combustion engine so as to generate a torque between the fourth instant and the third instant.

An electric vehicle driving apparatus is disclosed. The electric vehicle driving apparatus may include a driving motor, a plurality of shafts, a plurality of gears, a synchronizer, and a clutch. The electric vehicle driving apparatus may have a co-axial structure in which an input shaft and an output shafts are arranged coaxially, and may further include a bypass shaft that functions as a bypass path upon shifting. The electric vehicle driving apparatus may improve a spatial usability and may improve a shifting feeling by minimizing a shifting impact by continuously transmitting power despite a shifting operation.

According to various embodiments, an electric vehicle driving apparatus may include a driving motor, a plurality of shafts, a plurality of gears including a planetary gear set, a synchronizer, and a clutch. The electric vehicle driving apparatus may have a coaxial structure in which an input shaft connected to the driving motor is disposed coaxially with an output shaft connected to a wheel, and may continuously transmit power through a power bypass path when changing a speed. The electric vehicle driving apparatus may improve a spatial usability and improve shifting feeling by minimizing shift shock.