IP Library Granted Patent US 12,492,745
Granted Patent B2
US 12,492,745 · App. 18/620,723 · Granted Dec 9, 2025

Speed reducer, powertrain, and vehicle

Inventors: Feng Yuan (Beijing, CN); Lier Xie (Beijing, CN)
Assignee: XIAOMI EV TECHNOLOGY CO., LTD.
F16H57/0424
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Quick Facts
Patent No.
US 12,492,745
App. No.
18/620,723
Granted
Dec 9, 2025
Kind
B2
Abstract

A speed reducer includes a housing, a partition plate, and a reduction assembly. The housing defines a chamber and an oil passage. The partition plate is arranged in the housing to separate the chamber into a gear chamber and an oil chamber. The reduction assembly is arranged in the gear chamber, and the oil passage has an inlet in communication with the oil chamber and an outlet in communication with the gear chamber, and the outlet of the oil passage faces towards the reduction assembly to lubricate the reduction assembly.

Claims (44)

1 . A speed reducer, comprising:

a housing defining a chamber and an oil passage;

a partition plate arranged in the housing to separate the chamber into a gear chamber and an oil chamber; and

a reduction assembly arranged in the gear chamber, the oil passage having an inlet in communication with the oil chamber and an outlet in communication with the gear chamber, the outlet of the oil passage facing towards the reduction assembly to lubricate the reduction assembly,

wherein the reduction assembly comprises an input component, a transmission component and an output component, and the input component, the transmission component and the output component are arranged at intervals in a length direction of the housing; and

the oil passage comprises a main oil passage and a plurality of branch oil passages, and the plurality of branch oil passages has inlets in communication with the main oil passage and outlets respectively facing towards the input component, the transmission component and the output component to deliver lubricating oil to the reduction assembly;

wherein the input component comprises an input shaft and two input bearings, and the two input bearings are sleeved on the input shaft and respectively located at two ends of the input shaft; and

the plurality of branch oil passages comprises a first branch, and the first branch has an outlet facing towards the two input bearings; and

wherein the output component comprises an output shaft, an output gear and two output bearings; the two output bearings and the output gear are sleeved on the output shaft, the two output bearings are respectively located at two ends of the output shaft, and the output gear is located between the two output bearings; the transmission component further comprises an second transmission gear, and the output gear is engaged with the second transmission gear; and

the plurality of branch oil passages further comprises a fourth branch and a fifth branch, the fourth branch has an outlet facing towards the two output bearings, and the fifth branch has an outlet facing towards the output gear.

2 . The speed reducer according to claim 1 , wherein the gear chamber is located above the oil chamber.

3 . The speed reducer according to claim 1 , wherein the housing comprises two detachable sub-housings, each of the two sub-housings defines a groove, and the grooves in the two sub-housings enclose the oil passage.

4 . The speed reducer according to claim 1 , wherein the first branch located at a first end of the input shaft sprays the lubrication oil towards the input bearing located at the first end of the input shaft, and the first branch located at a second end of the input shaft sprays the lubrication oil towards the input bearing located at the second end of the input shaft.

5 . The speed reducer according to claim 1 , wherein the transmission component comprises a transmission shaft, a first transmission gear and two transmission bearings; the two transmission bearings and the first transmission gear are sleeved on the transmission shaft, the two transmission bearings are respectively located at two ends of the transmission shaft, and the first transmission gear is located between the two transmission bearings; the input component comprises an input gear, and the input gear is engaged with the first transmission gear; and

the plurality of branch oil passages further comprises a second branch and a third branch, the second branch has an outlet facing towards the input gear, and the third branch has an outlet facing towards the two transmission bearings.

6 . The speed reducer according to claim 5 , wherein the transmission shaft and the input shaft are arranged in parallel.

7 . The speed reducer according to claim 5 , wherein the third branch located at a first end of the transmission shaft sprays the lubrication oil towards the transmission bearing located at the first end of the transmission shaft, and the third branch located at a second end of the transmission shaft sprays the lubrication oil towards the transmission bearing located at the second end of the transmission shaft.

8 . The speed reducer according to claim 1 , wherein the output shaft and the input shaft are arranged in parallel.

9 . The speed reducer according to claim 1 , wherein the fourth branch located at a first end of the output shaft sprays the lubrication oil towards the output bearing located at the first end of the output shaft, and the fourth branch located at a second end of the output shaft sprays the lubrication oil towards the output bearing located at the second end of the output shaft.

10 . The speed reducer according to claim 1 , further comprising an oil scavenge pump arranged in the oil chamber, wherein the housing further defines an oil collection chamber, the partition plate defines an oil discharge port, and the oil collection chamber has an inlet in communication with the oil discharge port and an outlet in communication with the oil scavenge pump.

11 . The speed reducer according to claim 10 , further comprising a ventilation plug connected to the housing, wherein the ventilation plug is located in the oil chamber, and the ventilation plug has an installation height greater than a liquid level height inside the oil chamber.

12 . The speed reducer according to claim 11 , wherein the ventilation plug is located above the oil chamber, and the ventilation plug has a lower end extending into the oil chamber.

13 . A powertrain, comprising:

a speed reducer, comprising:

a housing defining a chamber and an oil passage;

a partition plate arranged in the housing to separate the chamber into a gear chamber and an oil chamber; and

a reduction assembly arranged in the gear chamber, the oil passage having an inlet in communication with the oil chamber and an outlet in communication with the gear chamber, the outlet of the oil passage facing towards the reduction assembly to lubricate the reduction assembly,

wherein the reduction assembly comprises an input component, a transmission component and an output component, and the input component, the transmission component and the output component are arranged at intervals in a length direction of the housing; and

the oil passage comprises a main oil passage and a plurality of branch oil passages, and the plurality of branch oil passages has inlets in communication with the main oil passage and outlets respectively facing towards the input component, the transmission component and the output component to deliver lubricating oil to the reduction assembly;

wherein the input component comprises an input shaft and two input bearings, and the two input bearings are sleeved on the input shaft and respectively located at two ends of the input shaft; and

the plurality of branch oil passages comprises a first branch, and the first branch has an outlet facing towards the two input bearings; and

wherein the output component comprises an output shaft, an output gear and two output bearings; the two output bearings and the output gear are sleeved on the output shaft, the two output bearings are respectively located at two ends of the output shaft, and the output gear is located between the two output bearings; the transmission component further comprises an second transmission gear, and the output gear is engaged with the second transmission gear; and

the plurality of branch oil passages further comprises a fourth branch and a fifth branch, the fourth branch has an outlet facing towards the two output bearings, and the fifth branch has an outlet facing towards the output gear.

14 . A vehicle, comprising:

a speed reducer, comprising:

a housing defining a chamber and an oil passage;

a partition plate arranged in the housing to separate the chamber into a gear chamber and an oil chamber; and

a reduction assembly arranged in the gear chamber, the oil passage having an inlet in communication with the oil chamber and an outlet in communication with the gear chamber, the outlet of the oil passage facing towards the reduction assembly to lubricate the reduction assembly,

wherein the reduction assembly comprises an input component, a transmission component and an output component, and the input component, the transmission component and the output component are arranged at intervals in a length direction of the housing; and

the oil passage comprises a main oil passage and a plurality of branch oil passages, and the plurality of branch oil passages has inlets in communication with the main oil passage and outlets respectively facing towards the input component, the transmission component and the output component to deliver lubricating oil to the reduction assembly;

wherein the input component comprises an input shaft and two input bearings, and the two input bearings are sleeved on the input shaft and respectively located at two ends of the input shaft; and

the plurality of branch oil passages comprises a first branch, and the first branch has an outlet facing towards the two input bearings; and

wherein the output component comprises an output shaft, an output gear and two output bearings; the two output bearings and the output gear are sleeved on the output shaft, the two output bearings are respectively located at two ends of the output shaft, and the output gear is located between the two output bearings; the transmission component further comprises an second transmission gear, and the output gear is engaged with the second transmission gear; and

the plurality of branch oil passages further comprises a fourth branch and a fifth branch, the fourth branch has an outlet facing towards the two output bearings, and the fifth branch has an outlet facing towards the output gear.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 28, 2024
From: YUAN, FENG; XIE, LIER
To: XIAOMI EV TECHNOLOGY CO., LTD.
Reel/Frame 066940/0780 →
Priority Claims (1)
CN 202310936586.1 · Jul 27, 2023 · national
Continuity (1)
Related Publication 20250035207A1 · Jan 30, 2025
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