REDUCTION GEAR AND ELECTROMECHANICAL DEVICE

• US 20200132165A1
• Filed: 10/07/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Nidec Corporation
• Original Assignee: Nidec Corporation
• Inventors: YAN, Guo-Jhih, NGO, Huu-Tich
• Granted Patent: US 11,078,989 B2
• Time in Patent Office: Days
• CPC Class Codes: F16H 1/28 with gears having orbital motion
• CPC Class Codes: F16H 2057/02034 Gearboxes combined or connected with electric machines structural association with electric machines H02K7/116
• CPC Class Codes: F16H 57/021 Shaft support structures, e.g. partition walls, bearing eyes, casing walls or covers with bearings
• CPC Class Codes: F16H 57/08 of gearings with members having orbital motion
• CPC Class Codes: H02K 1/182 to stators axially facing the rotor, i.e. with axial or conical air gap
• CPC Class Codes: H02K 1/2798 where both axial sides of the stator face a rotor
• CPC Class Codes: H02K 16/02 Machines with one stator and two or more rotors
• CPC Class Codes: H02K 7/003 Couplings; Details of shafts means for mounting rotors on shafts H02K1/28
• CPC Class Codes: H02K 7/08 Structural association with bearings
• CPC Class Codes: H02K 7/116 with gears

Abstract

A reduction gear and an electromechanical device are provided. The reduction gear has a motor and a speed reduction assembly. The motor has a first rotary shaft and a second rotary shaft which rotate around a central axis, a second rotor, a first rotor, a stator and a first motor housing; the speed reduction assembly has: a first gear, a second gear, a third gear, and an output shaft driven by the third gear; and the motor further has: a first bearing and a second bearing, the first bearing and the second bearing are located on two sides of the stator in an axial direction, and the first gear is located on one side, away from the stator, of the second rotor. According to the embodiments, the reduction gear which is small in size and high in drive capability may be obtained.

Claims

1. A reduction gear, comprising a motor and a speed reduction assembly, wherein the motor comprises:

a first rotary shaft and a second rotary shaft which rotate around a central axis,

a second rotor and a first rotor which are disposed on radial outer sides of the second rotary shaft and the first rotary shaft respectively,

a stator disposed between the second rotor and the first rotor, and

a first motor housing disposed on an axial side, away from the stator, of the first rotor;

the speed reduction assembly comprises

a first gear disposed on one side, away from the first rotor, of the second rotor,

a second gear and a third gear which mesh with the first gears, and

an output shaft driven by the third gear; and

the motor further comprises;

a first bearing disposed on a radial inner side of the first rotary shaft, and

a second bearing disposed on a radial inner side of the second rotary shaft or the output shaft,

the first bearing and the second bearing are located on two sides of the stator in an axial direction, and

the first gear is located on one side, away from the stator, of the second rotor.

2. The reduction gear according to claim 1, wherein

the second rotary shaft comprises a first concave portion, and

the second bearing is located inside the first concave portion.

3. The reduction gear according to claim 2, wherein

on a side back on to the first motor housing,

an end face of the second rotary shaft is farther away from the first motor housing than an end face of the second bearing, or, the end face of the second rotary shaft coincides with the end face of the second bearing.

4. The reduction gear according to claim 1, wherein

the output shaft comprises a second concave portion on a radial inner side, and

the second bearing is located in the second concave portion.

5. The reduction gear according to claim 4, wherein

on a side facing toward the first motor housing,

an end face of the output shaft is closer to the first motor housing than an end face of the second bearing, or, the end face of the output shaft coincides with the end face of the second bearing.

6. The reduction gear according to claim 1, wherein

a support is further arranged between the output shaft and the first gear, the support abuts against a rotary shaft of the first gear, the first gear rotates around the rotary shaft, and the rotary shaft is fixed to the second rotor.

7. The reduction gear according to claim 1, wherein

two or more first gears are provided, and the two or more first gears are disposed with the central axis as a center.

8. The reduction gear according to claim 7, wherein

the second gear and the third gear are ring gears or sun gears, and the first gears are planet gears.

9. The reduction gear according to claim 8, wherein

when the second gear and the third gear are the ring gears, an inner diameter of the second gear and an inner diameter of the third gear are the same or different;

and

when the second gear and the third gear are the sun gears, an outer diameter of the second gear and an outer diameter of the third gear are the same or different.

10. The reduction gear according to claim 8, wherein

when the second gear and the third gear are the ring gears, the reduction gear further comprises a fourth gear, and the fourth gear is a sun gear and located on a radial inner side of the first gears.

11. The reduction gear according to claim 10, wherein

the reduction gear further comprises a collar which is arranged at an end, facing the second rotor, of the second gear and abuts against ends, facing the second rotor, of the first gears.

12. The reduction gear according to claim 1, wherein

the second bearing is disposed on the radial inner side of the first gears, the second gear and the third gear.

13. The reduction gear according to claim 1, wherein

the second bearing is located between radial directions of the second rotary shaft and the output shaft.

14. The reduction gear according to claim 1, wherein

the reduction gear is further provided with a center shaft,

the center shaft is located on radial inner sides of the first rotary shaft and the second rotary shaft, and

the center shaft abuts against the output shaft in the axial direction.

15. The reduction gear according to claim 1, wherein

the speed reduction assembly further comprises:

a bearing disposed on a radial outer side of the output shaft.

16. The reduction gear according to claim 1, wherein

the motor is an axial flux motor.

17. An electromechanical device, wherein

the electromechanical device comprises the reduction gear of claim 1.