Electric vehicle drive device

Patent metadata

Field	Value
Publication number	US-11305653-B2
Application number	US-201716334905-A
Country	US
Kind code	B2
Filing date	Sep 15, 2017
Priority date	Sep 21, 2016
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

An electric vehicle drive device includes: a first motor; a second motor; a transmission mechanism coupled to the first motor and the second motor; and a control unit configured to control operation of the first motor and the second motor based on a drive signal. The transmission mechanism includes: a sun gear shaft coupled to the first motor; a first planetary gear mechanism; a second planetary gear mechanism; and a one-way clutch configured to restrict a rotation direction of a first carrier to a predetermined positive rotation direction. The drive signal includes gear change information indicating a first state in which the second motor is controlled based on torque or a second state in which the second motor is controlled based on rotation speed, and throttle information indicating an acceleration of rotation speed of a wheel.

First claim

The invention claimed is:

1. An electric vehicle drive device, comprising:
a first motor;
a second motor;
a detection unit configured to detect rotation speed of the first motor;
a filtering unit configured to converge an increase/decrease amount of the rotation speed of the first motor detected by the detection unit;
a transmission mechanism coupled to the first motor and the second motor; and
a control unit configured to control operation of the first motor and the second motor based on a drive signal, wherein
the transmission mechanism comprises:
a sun gear shaft coupled to the first motor;
a first planetary gear mechanism including a first sun gear configured to rotate together with the sun gear shaft, a first pinion gear engaged with the first sun gear, a first ring gear engaged with the first pinion gear and coupled to the second motor, and a first carrier that is provided to be rotatable about the sun gear shaft and supports the first pinion gear, and
a second planetary gear mechanism including a second sun gear configured to rotate together with the sun gear shaft, a second pinion gear engaged with the second sun gear, a third pinion gear engaged with the second pinion gear, a second ring gear engaged with the third pinion gear and 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,

the drive signal includes gear change information indicating a first state in which torque of the second motor is controlled or a second state in which rotation speed of the second motor is controlled and throttle information indicating an acceleration of rotation speed of a wheel, and
based on determining that the drive signal includes the gear change information indicating the first state, the control unit determines a first command value based on the throttle information, the first command value being a torque command value of the first motor for the positive rotation direction, and controls the first motor in accordance with the first command value, and determines a second command value based on the throttle information, the second command value being a torque command value of the second motor for a rotation direction reverse to the positive rotation direction, and controls the second motor in accordance with the second command value, and
wherein, in a case where the first motor is rotated in a rotation direction reverse to the positive rotation direction and the second motor is rotated in the positive rotation direction, when the rotation speed of the first motor is represented by N MA , the rotation speed of the second motor is represented by N MB , a reduction ratio in the first planetary gear mechanism is represented by i 1 , and a reduction ratio in the second planetary gear mechanism is represented by i 2 , the control unit determines N MB within a range indicated by Equation (1):

-

1

i
1

×

N
MA

≤

N
MB

<

(

1

1
-

i
2

)

×

N
MA

.

(
1
)

2. An electric vehicle drive device, comprising:
a first motor;
a second motor;
a transmission mechanism coupled to the first motor and the second motor; and
a control unit configured to control operation of the first motor and the second motor based on a drive signal, wherein
the transmission mechanism comprises:
a sun gear shaft coupled to the first motor;
a first planetary gear mechanism including a first sun gear configured to rotate together with the sun gear shaft, a first pinion gear engaged with the first sun gear, a first ring gear engaged with the first pinion gear and coupled to the second motor, and a first carrier provided to be rotatable about the sun gear shaft and supports the first pinion gear;
a second planetary gear mechanism including a second sun gear configured to rotate together with the sun gear shaft, a second pinion gear engaged with the second sun gear, a third pinion gear engaged with the second pinion gear, a second ring gear engaged with the third pinion gear and 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 detection unit configured to detect rotation speed of the first motor; and
a filtering unit configured to converge an increase/decrease amount of the rotation speed of the first motor detected by the detection unit,

the drive signal includes gear change information indicating a first state in which torque of the second motor is controlled or a second state in which rotation speed of the second motor is controlled and throttle information indicating an acceleration of rotation speed of a wheel, and
based on determining that the drive signal includes the gear change information indicating the second state, the control unit determines a torque command value of the first motor for the positive rotation direction based on the throttle information and controls the first motor in accordance with the torque command value, and determines a rotation speed command value corresponding to the rotation speed of the first motor detected by the detection unit and controls the second motor in accordance with the rotation speed command value, and
wherein, in a case where the first motor is rotated in a rotation direction reverse to the positive rotation direction and the second motor is rotated in the positive rotation direction, when the rotation speed of the first motor is represented by N MA , the rotation speed of the second motor is represented by N MB , a reduction ratio in the first planetary gear mechanism is represented by i 1 , and a reduction ratio in the second planetary gear mechanism is represented by i 2 , the control unit determines N MB within a range indicated by Equation (1):

-

1

i
1

×

N
MA

Assignees

• Nsk Ltd

Inventors

• Morita Ryuho
• Matsuda Yasuyuki
• Oike Mitsuru
• Gunji Daisuke
• Yamamoto Shin

Classifications

• Y02T10/64

  Electric machine technologies in electromobility · CPC title

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• F16H2200/0021

  specially adapted for electric vehicles · CPC title

• F16H3/725

  with means to change ratio in the mechanical gearing · CPC title

• B60L2270/145

  Structure borne vibrations · CPC title