IP Library Granted Patent US 12686277
Granted Patent B2
US 12686277 · App. 18/944,534 · Granted Jul 21, 2026

Independent right-left wheel driving vehicle

Inventors: Koichi Katayama (Okazaki, JP); Koichi Okuda (Toyota, JP); Atsushi Tabata (Okazaki, JP)
Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
B60L3/0061B60L15/2036B60L2240/24B60L2240/423B60L2240/425
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Quick Facts
Patent No.
US 12686277
App. No.
18/944,534
Granted
Jul 21, 2026
Kind
B2
Abstract

A temperature detecting unit for detecting the temperature of the left electric motor and the temperature of the right electric motor, a temperature determination unit for determining that the temperature of one of the detected temperatures is outside the predetermined temperature range, a driving force limiting unit for reducing driving torque of the other electric motor that is not outside the temperature range when it is determined that one of the temperature of the left electric motor and the temperature of the right electric motor is outside the temperature range, and a driving torque increasing unit for increasing driving torque by the other driving device that does not include the one electric motor that is outside the temperature range among the first driving device and the second driving device when driving torque of the other electric motor is reduced.

Claims (30)

1 . An independent right-left wheel driving vehicle including a first driving device configured to drive right and left front wheels, and a second driving device configured to drive right and left rear wheels, in which at least one of the first driving device or the second driving device includes a left electric motor that drives a left wheel and a right electric motor that drives a right wheel making up a pair with the left wheel, the independent right-left wheel driving vehicle comprising:

a temperatures sensor configured to detect a left electric motor temperature of the left electric motor and a right electric motor temperature of the right electric motor;

a processor; and

a memory storing executable instructions that cause the processor to

acquire the left electric motor temperature and the right electric motor temperature from the temperature sensor,

determine whether either of the left electric motor temperature or the right electric motor temperature falls outside a predetermined temperature range,

reduce driving torque of the other electric of the left electric motor temperature or the right electric motor for which the detected temperature does not fall outside the predetermined temperature range in response to determining that temperature of either of the left electric motor or the right electric motor falls outside the predetermined temperature range, and

increase driving torque of the other driving device of the first driving device or the second driving device that does not include the one electric motor having the temperature outside the temperature range, from among the first driving device and the second driving device in response to the driving torque of the other electric motor being reduced, wherein

the left electric motor and the right electric motor of the at least one of the first driving device or the second driving device are mounted such that rotational center axes of both the left electric motor and the right electric motor extend in a direction parallel to the longitudinal direction of the independent right-left wheel driving vehicle.

2 . The independent right-left wheel driving vehicle according to claim 1 , wherein:

the other driving device of the first driving device or the second driving device includes a traction electric motor as a driving force source, and

the executable instructions further cause the processor to acquire a traction electric motor temperature of the traction electric motor;

determine whether the traction electric motor temperature falls within a predetermined steady-state range; and

prohibit increasing the driving torque in response to determining that the traction electric motor temperature does not fall within the predetermined steady-state range.

3 . The independent right-left wheel driving vehicle according to claim 1 , wherein the executable instructions further cause the processor to

determine four-wheel drive traveling in which the first driving device and the second driving device output drive torque to perform traveling;

reduce driving torque of the other electric motor when the four-wheel drive traveling is determined to be performed; and

increase driving torque of the other driving device when the four-wheel drive traveling is determined to be performed.

4 . The independent right-left wheel driving vehicle according to claim 1 , wherein the executable instructions further cause the processor to

determine whether the vehicle is performing a turn, and

prohibit reduction of driving torque at the other electric motor in response to determining that the vehicle is performing a turn.

5 . The independent right-left wheel driving vehicle according to claim 1 , wherein the predetermined temperature range is one of either a range in which only an upper-limit temperature is set, or a range in which the upper limit temperature and a lower-limit temperature are both set.

6 . The independent right-left wheel driving vehicle according to claim 1 , wherein the driving device of the at least one of the first driving device or the second driving device including the left electric motor and the right electric motor further comprises a casing that accommodates the left electric motor and the right electric motor in a liquid-tight manner.

7 . The independent right-left wheel driving vehicle according to claim 6 , further comprising:

at least one oil pump provided outside the casing, wherein the at least one oil pump is configured to supply oil to the left electric motor and the right electric motor to cool and lubricate the left electric motor and the right electric motor.

8 . The independent right-left wheel driving vehicle according to claim 7 , wherein the at least one oil pump is an electric oil pump.

9 . The independent right-left wheel driving vehicle according to claim 1 , wherein the temperature sensor is a plurality of temperature sensors provided at each of the left electric motor and the right electric motor.

10 . The independent right-left wheel driving vehicle according to claim 1 , wherein

the temperature sensor is a plurality of temperature sensors provided for each of the left electric motor and the right electric motor, and

the plurality of sensors being configured to detect an oil temperature of oil that is returned to an oil reservoir from each of the left electric motor and the right electric motor.