Electric vehicle drive apparatus

An electric vehicle drive apparatus comprising:

• a first motor;
• a second motor;
• a speed change mechanism coupled to the first motor and the second motor;
• and
• a controller controlling operation of the first motor and the second motor based on a drive signal;
• and
• a detector detecting a rotation speed of the first motor,
• the speed change mechanism including:
• a sun gear shaft coupled to the first motor;
• a first planetary gear mechanism having a first sun gear rotating together with the sun gear shaft, a first pinion gear meshing with the first sun gear, a first ring gear that meshes with the first pinion gear and is coupled to the second motor, and a first carrier that is provided rotatably about the sun gear shaft and supports the first pinion gear;
• a second planetary gear mechanism having a second sun gear rotating together with the sun gear shaft, a second pinion gear meshing with the second sun gear, a third pinion gear meshing with the second pinion gear, a second ring gear that meshes with the third pinion gear and is coupled to an output shaft, and a second carrier that supports the second pinion gear and the third pinion gear and is coupled to the first ring gear to rotate about the sun gear shaft;
• and
• a one-way clutch limiting a rotation direction of the first carrier to a certain forward rotation direction, and
• a rotation direction of a wheel coupled to the output shaft being the same as a rotation direction of the first motor,
• the drive signal including information directing rotation of the wheel in the forward rotation direction or a backward rotation direction opposite to the forward rotation direction and throttle information indicating an acceleration of a rotation speed of the wheel, and when including information directing rotation of the wheel in the forward rotation direction, the drive signal further including speed change information indicating whether a current state is a first state that performs control of the second motor based on torque or a second state that performs control of the second motor based on rotation speed,
• the controller, when rotating the first motor in a backward rotation direction opposite to the forward rotation direction and rotating the second motor in the forward rotation direction, where a rotation speed of the first motor is NMA, a rotation speed of the second motor is NMB, a reduction ratio of the first planetary gear mechanism is i1, and a reduction ratio of the second planetary gear mechanism is i2, determining NMB within a range indicated by Expression (1),
• the controller determining, based on the drive signal, rotation directions of the first motor and the second motor and based on which of torque and rotation speed control of the second motor is performed, and when the drive signal includes information directing rotation of the wheel in the backward rotation direction, outputting a rotation speed command in the backward rotation direction to the first motor and outputting a rotation speed command in the forward rotation direction to the second motor, and when the speed change information indicates the second state, determining a torque command value in the forward rotation direction of the first motor based on the throttle information to operate the first motor in accordance with the torque command value, and determining a rotation speed command value corresponding to the rotation speed of the first motor detected by the detector to operate the second motor in accordance with the rotation speed command value
• -
• 1
• i
• 1
• ×
• N
• MA
• ≤
• N
• MB
• <
• (
• 1
• 1
• -
• i
• 2
• )
• ×
• N
• MA
• .
• (
• 1
• )