# US 12,760,791 B2 · Transaxle

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- Number: US 12,760,791 B2
- Document ID: US12760791B2
- Status: Granted
- Kind: B2
- Application number: 19/317,662
- Filed: 2025-09-03
- Published: 2026-03-05
- Granted: 2026-10-13
- Earliest claimed: 2024-09-04
- Assignees: Toyota Jidosha Kabushiki Kaisha; Aisin Corporation
- Applicants: Toyota Jidosha Kabushiki Kaisha; Aisin Corporation
- Inventors: Hiroki Inokura; Mizuki Bingo; Takashi Hasumi; Takayori Yamauchi; Masaki Yoshida; Satoshi Miyanaga; Yuki Kosaka
- Web page: https://patentgrep.com/patent/US12760791B2

## CPC

- F16H 57/043: {within rotary parts, e.g. axial channels or radial openings in shafts}
- B60K 17/165: {provided between independent half axles (B60K17/18, B60K17/20 take precedence)}
- F16H 57/021: Shaft support structures, e.g. partition walls, bearing eyes, casing walls or covers with bearings
- F16H 57/0415: {Air cooling or ventilation; Heat exchangers; Thermal insulations}
- F16H 57/0436: {Pumps}
- F16H 57/045: {Lubricant storage reservoirs, e.g. reservoirs in addition to a gear sump for collecting lubricant in the upper part of a gear case}
- F16H 57/0457: {Splash lubrication}
- F16H 57/0471: {Bearing}
- F16H 57/0483: {Axle or inter-axle differentials}
- B60K 6/365: with the gears having orbital motion
- B60K 6/405: Housings
- B60Y 2200/92: Hybrid vehicles
- B60Y 2400/80: Differentials
- F16H 2057/02034: {Gearboxes combined or connected with electric machines}
- F16H 2057/02052: {Axle units; Transfer casings for four wheel drive}
- H02K 7/116: with gears
- F16H: GEARING
- B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})

## Abstract

A transaxle mounted on a vehicle includes a shaft that integrally rotates together with both a coupling gear included in a gear mechanism and a rotor of an electric motor that is spaced apart from the coupling gear in an axial direction; a first oil passage formed in the shaft and configured to guide the oil scooped up by at least one gear included in the gear mechanism and supplied to an end portion of the shaft on the side of the coupling gear to a predetermined cooling target in a case; a second oil passage formed in the shaft and configured to guide the oil supplied from a pump to an end portion of the shaft on the side of the rotor; and a closure disposed in the shaft and configured to guide restrict communication between the first oil passage and the second oil passage.

## Claims

### Claim 1

A transaxle that is mounted on a vehicle and includes an electric motor, a gear mechanism that includes at least a differential gear and is connected to the electric motor, a case that houses the electric motor and the gear mechanism, and a pump that sucks oil reserved in the case and discharges the oil, the transaxle comprising:
a shaft that integrally rotates together with both a coupling gear included in the gear mechanism and a rotor of the electric motor that is spaced apart from the coupling gear in an axial direction;
a first oil passage formed in the shaft and configured to guide the oil scooped up by at least one gear included in the gear mechanism and supplied to an end portion of the shaft on the side of the coupling gear to a predetermined cooling target in the case;
a second oil passage formed in the shaft and configured to guide the oil supplied from the pump to an end portion of the shaft on the side of the rotor; and
a closure disposed in the shaft and configured to restrict communication between the first oil passage and the second oil passage;
wherein:
the shaft includes a first shaft with the first oil passage and rotates integrally with the coupling gear, and a second shaft with the second oil passage and is fixed to the rotor;
the first shaft is fitted within the second oil passage and configured to rotate integrally with the second shaft;
the closure is formed at an end of the first shaft on the side of the second shaft;
the first and second shafts are connected in a rotational direction via a spline fitting portion, and are also connected coaxially via a spigot fitting portion in which an outer circumference surface of the first shaft closely contacts an inner circumference surface of the second shaft on the side of the coupling gear of the spline fitting portion;
the cooling target is the spigot fitting portion; and
a part of the oil supplied to the second oil passage passes through the spline fitting portion and flows into the spigot fitting portion.

### Claim 2 (depends on 1)

The transaxle according to claim 1, wherein:
the shaft includes a first oil supply hole that communicates with the first oil passage and supplies the oil to the side of the cooling target, and a second oil supply hole that communicates with the second oil passage and opens on an outer circumference surface of the shaft that is surrounded by an inner circumference surface of the rotor;
the closure is arranged between the first oil supply hole and the second oil supply hole in the axial direction; and
the oil discharged from the pump is supplied to the second oil passage via an oil cooler.

### Claim 3 (depends on 2)

The transaxle according to claim 2, further comprising:
a first bearing that supports the end portion of the shaft on the side of the coupling gear;
a second bearing that supports the end portion of the shaft on the side of the rotor; and
an intermediate bearing that supports the shaft between the coupling gear and the rotor in the axial direction,
wherein the first oil supply hole is disposed between the intermediate bearing and an end face of the rotor on the side of the coupling gear in the axial direction.