US-20260126113-A1 - DRIVE UNIT

US20260126113A1US 20260126113 A1US20260126113 A1US 20260126113A1US-20260126113-A1

Abstract

A drive unit may be configured to drive a pair of wheels independently from each other. A casing of the drive unit may include a first portion disposed on one side of the pair of wheels and a second portion disposed on another side of the pair of wheels when the drive unit is mounted in a vehicle. A first motor, a first reduction drive, a first inverter, and a lock mechanism configured to mechanically lock and unlock the first reduction drive may be disposed in the first portion. The second motor, the second reduction drive, and the second inverter may be disposed in the second portion. A motor central plane located between and equidistant from the first and second motors may be offset closer to the second portion relative to an inverter central plane located between and equidistant from the first and second inverters.

Inventors

Yusuke Suzuki
Koichi Okuda
Eiji Ito
Naoki Saito

Assignees

TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date: 20260507
Application Date: 20251010
Priority Date: 20241106

Claims (10)

1 . A drive unit for a vehicle and configured to drive a pair of left and right wheels independently from each other, the drive unit comprising: a first motor configured to drive one of the left and right wheels; a first reduction drive configured to reduce rotation of the first motor; a first inverter electrically connected to the first motor; a second motor configured to drive another of the left and right wheels; a second reduction drive configured to reduce rotation of the second motor; a second inverter electrically connected to the second motor; a lock mechanism configured to mechanically lock and unlock the first reduction drive; and a casing housing the first motor, the first reduction drive, the first inverter, the second motor, the second reduction drive, the second inverter, and the lock mechanism, wherein the casing comprises a first portion and a second portion, wherein the first portion is disposed on one side of the pair of left and right wheels and the second portion is disposed on another side of the pair of left and right wheels when the drive unit is mounted in the vehicle, the first motor, the first reduction drive, the first inverter, and the lock mechanism are disposed in the first portion of the casing, the second motor, the second reduction drive, and the second inverter are disposed in the second portion of the casing, and a motor central plane located between and equidistant from the first motor and the second motor is offset closer to the second portion of the casing relative to an inverter central plane located between and equidistant from the first inverter and the second inverter.
2 . The drive unit according to claim 1 , wherein the casing comprises a first oil pan provided at a lower part of the first portion and a second oil pan provided at a lower part of the second portion, and an oil pan central plane located between and equidistant from the first oil pan and the second oil pan is offset closer to the first portion of the casing relative to the motor central plane.
3 . The drive unit according to claim 1 , wherein the drive unit is connected to a first drive shaft connected to the one of the left and right wheels and a second drive shaft connected to the other of the left and right wheels, and wherein a center of gravity of the drive unit is located on an inboard central plane located between and equidistant from a first drive shaft inboard portion of the first drive shaft and a second drive shaft inboard portion of the second drive shaft.
4 . The drive unit according to claim 1 , further comprising: a first terminal block secured to the casing; a first conductive path electrically connecting the first inverter and the first motor via the first terminal block; a second terminal block secured to the casing; and a second conductive path electrically connecting the second inverter and the second motor via the second terminal block, wherein a total length of the first conductive path and a total length of the second conductive path are different from each other, and a section length of the first conductive path from the first motor to the first terminal block and a section length of the second conductive path from the second motor to the second terminal block are equal to each other.
5 . The drive unit according to claim 1 , wherein the first motor and the second motor are arranged symmetrically with respect to the motor central plane.
6 . The drive unit according to claim 1 , wherein the first inverter and the second inverter are arranged symmetrically with respect to the inverter central plane.
7 . The drive unit according to claim 1 , wherein the casing comprises: a first motor chamber being located in the first portion and housing the first motor and the first reduction drive; a second motor chamber being located in the second portion and housing the second motor and the second reduction drive; and a motor chamber bulkhead being located on the motor central plane and at least partially separating the first motor chamber and the second motor chamber from each other.
8 . The drive unit according to claim 7 , wherein the casing further comprises: a first inverter chamber being located in the first portion and housing the first inverter, a second inverter chamber being located in the second portion and housing the second inverter, and an inverter chamber bulkhead being located on the inverter central plane and at least partially separating the first inverter chamber and the second inverter chamber from each other.
9 . The drive unit according to claim 1 , wherein the lock mechanism is provided on a rotary axis connecting the first motor and the first reduction drive.
10 . The drive unit according to claim 9 , wherein the lock mechanism comprises: a lock gear secured to the rotary axis; and a lock pole configured to move between a lock position in which the lock pole is engaged with the lock gear and an unlock position in which the lock pole is disengaged from the lock gear.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to Japanese Patent Application No. 2024-194615 filed on Nov. 6, 2024. The entire content of the priority application is incorporated herein by reference. TECHNICAL FIELD The art disclosed herein relates to a drive unit for a vehicle. BACKGROUND ART Japanese Patent Application Publication No. 2017-047698 describes a drive unit for a vehicle. The drive unit includes two motors and two reduction drives, and is configured to drive a pair of right and left wheels independently from each other. SUMMARY In the above-mentioned drive unit, the two motors and the two reduction drives are disposed symmetrically. In the drive unit configured to drive the pair of right and left wheels independently from each other, it is desirable to arrange its constituent features in a pair such as motors and reduction drives in a balanced manner on left and right sides as in the above-mentioned drive unit. However, the constituent features of the drive unit further include features which do not form a pair, such as a lock mechanism. The lock mechanism is also referred to as a parking lock, for example, and is disposed on one of the two reduction drives, and is configured to lock and unlock the one reduction drive. The presence of the lock mechanism creates mass imbalance in the drive unit between the left and right sides. The present teachings provide an art configured to suppress such imbalance. The techniques disclosed herein are embodied by a drive unit for a vehicle. The drive unit may be configured to drive a pair of left and right wheels independently from each other. The drive unit may comprise: a first motor configured to drive one of the left and right wheels; a first reduction drive configured to reduce rotation of the first motor; a first inverter electrically connected to the first motor; a second motor configured to drive another of the left and right wheels; a second reduction drive configured to reduce rotation of the second motor; a second inverter electrically connected to the second motor; a lock mechanism configured to mechanically lock and unlock the first reduction drive; and a casing housing the first motor, the first reduction drive, the first inverter, the second motor, the second reduction drive, the second inverter, and the lock mechanism, wherein the casing may comprise a first portion and a second portion, in which the first portion may be disposed on one side of the pair of left and right wheels and the second portion may be disposed on another side of the pair of left and right wheels when the drive unit is mounted in the vehicle, the first motor, the first reduction drive, the first inverter, and the lock mechanism may be disposed in the first portion of the casing, the second motor, the second reduction drive, and the second inverter may be disposed in the second portion of the casing, and a motor central plane located between and equidistant from the first motor and the second motor may be offset closer to the second portion of the casing relative to an inverter central plane located between and equidistant from the first inverter and the second inverter. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 illustrates a block diagram showing a vehicle in a top view. FIG. 2 illustrates a schematic view of a drive unit. FIG. 3 illustrates a schematic view of the drive unit. FIG. 4 illustrates a configuration of a lock mechanism. FIG. 5 illustrates an enlarged view of a section V in FIG. 2. DETAILED DESCRIPTION In a first aspect, a drive unit for a vehicle may be configured to drive a pair of left and right wheels independently from each other. The drive unit may comprise: a first motor configured to drive one of the left and right wheels; a first reduction drive configured to reduce rotation of the first motor; a first inverter electrically connected to the first motor; a second motor configured to drive another of the left and right wheels; a second reduction drive configured to reduce rotation of the second motor; a second inverter electrically connected to the second motor; a lock mechanism configured to mechanically lock and unlock the first reduction drive; and a casing housing the first motor, the first reduction drive, the first inverter, the second motor, the second reduction drive, the second inverter, and the lock mechanism. The casing may comprise a first portion and a second portion. The first portion may be disposed on one side of the pair of left and right wheels and the second portion may be disposed on another side of the pair of left and right wheels when the drive unit is mounted in the vehicle. The first motor, the first reduction drive, the first inverter, and the lock mechanism may be disposed in the first portion of the casing. The second motor, the second reduction drive, and the second inverter may be disposed in the second portion of the casing, and a motor central plane located between and equidistant from the first moto