IP Library › Granted Patent US 12,445,002
Granted Patent B2
US 12,445,002 · App. 18/108,400 · Granted Oct 14, 2025

Magnet-embedded rotating machine with magnets having different coercive forces

Inventors: Yoshihito Sanga (Osaka, JP); Yoshinari Asano (Osaka, JP)
Assignee: DAIKIN INDUSTRIES, LTD.
H02K1/2766H02K2213/03
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,445,002
App. No.
18/108,400
Granted
Oct 14, 2025
Kind
B2
Abstract

A magnet-embedded rotating machine includes a rotor including first and second magnets, and a stator. The first magnet is radially spaced from a facing surface of the stator by a first distance or longer, and the second magnet is radially spaced from the facing surface of the stator by a second distance or longer, the second distance being longer than the first distance. Hco(A)>Hco(B), Hci(A)>Hci(B), Hco(A)>Hci(A), and {Hco(A)/Hci(A)}>{Hco(B)/Hci(B)}. Hco(A) represents a coercive force of the first magnet within a first temperature range corresponding to startup temperatures of the rotating machine. Hco(B) represents a coercive force of the first magnet within a second temperature range corresponding to steady state driving temperatures of the rotating machine. Hci(A) represents a coercive force of the second magnet within the first temperature range. Hci(B) represents a coercive force of the second magnet within the second temperature range.

Claims (57)

1. A magnet-embedded rotating machine comprising:

a rotor rotatable about a shaft; and

a stator having a facing surface radially facing a peripheral surface of the rotor with a gap interposed therebetween,

the rotor including

a first magnet embedded in an area that is radially spaced from the facing surface of the stator by a first distance or longer, and

a second magnet embedded in an area that is radially spaced from the facing surface of the stator by a second distance or longer, the second distance being longer than the first distance,

Hco ( A )> Hco ( B ),

Hci ( A )> Hci ( B ),

Hco ( A )> Hci ( A ), and

{ Hco ( A )/ Hci ( A )}>{ Hco ( B )/ Hci ( B )}, with

Hco(A) representing a coercive force of the first magnet within a first temperature range corresponding to temperatures at a startup of the rotating machine,

Hco(B) representing a coercive force of the first magnet within a second temperature range corresponding to temperatures during steady-state driving of the rotating machine,

Hci(A) representing a coercive force of the second magnet within the first temperature range,

Hci(B) representing a coercive force of the second magnet within the second temperature range,

the first magnet being a neodymium magnet, or a neodymium magnet in which a portion of neodymium is replaced with lanthanum or cerium, and

the second magnet being a samarium-cobalt magnet, or a neodymium magnet in which a portion of neodymium is replaced with lanthanum or cerium.

2. The magnet-embedded rotating machine of claim 1 , wherein

Hco ( t 1)= Hco ( t 0){1−β o ( t 1− t 0)},

Hci ( t 1)= Hci ( t 0){1− βi ( t 1− t 0)},

t1 and t0 represent temperatures,

βo and βi represent temperature coefficients of the coercive force of the first and second magnets respectively and

β o>βi> 0.

3. The magnet-embedded rotating machine of claim 2 , wherein Hco(B)>Hci(B).

4. The magnet-embedded rotating machine of claim 2 , wherein

the first temperature range is from −20° C. to 40° C., and

the second temperature range is from 100° C. to 200° C.

5. The magnet-embedded rotating machine of claim 2 , wherein

the first magnet is embedded in a first pattern arranged in a form of a straight line, a bent line, or a curve, extending to be more distant from the facing surface of the stator toward the middle of the first pattern, and

the second magnet is embedded in a second pattern arranged in a form of a bent line or a curve, extending to be more distant from the facing surface of the stator toward the middle of the second pattern, the second pattern being more distant from the facing surface of the stator than the first pattern.

6. The magnet-embedded rotating machine of claim 2 , wherein

the first magnet is embedded in portions of a third pattern arranged in a form of a straight line, a bent line, or a curve, extending to be more distant from the facing surface of the stator toward the middle of the third pattern, and

the second magnet is embedded in the third pattern so as to be positioned closer to the middle of the third pattern compared to the first magnet.

7. The magnet-embedded rotating machine of claim 1 , wherein Hco(B)>Hci(B).

8. The magnet-embedded rotating machine of claim 3 , wherein

the first temperature range is from −20° C. to 40° C., and

the second temperature range is from 100° C. to 200° C.

9. The magnet-embedded rotating machine of claim 7 , wherein

the first magnet is embedded in a first pattern arranged in a form of a straight line, a bent line, or a curve, extending to be more distant from the facing surface of the stator toward the middle of the first pattern, and

the second magnet is embedded in a second pattern arranged in a form of a bent line or a curve, extending to be more distant from the facing surface of the stator toward the middle of the second pattern, the second pattern being more distant from the facing surface of the stator than the first pattern.

10. The magnet-embedded rotating machine of claim 7 , wherein

the first magnet is embedded in portions of a third pattern arranged in a form of a straight line, a bent line, or a curve, extending to be more distant from the facing surface of the stator toward the middle of the third pattern, and

the second magnet is embedded in the third pattern so as to be positioned closer to the middle of the third pattern compared to the first magnet.

11. The magnet-embedded rotating machine of claim 1 , wherein

the first temperature range is from −20° C. to 40° C., and

the second temperature range is from 100° C. to 200° C.

12. The magnet-embedded rotating machine of claim 11 , wherein

the first magnet is embedded in a first pattern arranged in a form of a straight line, a bent line, or a curve, extending to be more distant from the facing surface of the stator toward the middle of the first pattern, and

the second magnet is embedded in a second pattern arranged in a form of a bent line or a curve, extending to be more distant from the facing surface of the stator toward the middle of the second pattern, the second pattern being more distant from the facing surface of the stator than the first pattern.

13. The magnet-embedded rotating machine of claim 11 , wherein

the first magnet is embedded in portions of a third pattern arranged in a form of a straight line, a bent line, or a curve, extending to be more distant from the facing surface of the stator toward the middle of the third pattern, and

the second magnet is embedded in the third pattern so as to be positioned closer to the middle of the third pattern compared to the first magnet.

14. The magnet-embedded rotating machine of claim 1 , wherein

the first magnet is embedded in a first pattern arranged in a form of a straight line, a bent line, or a curve, extending to be more distant from the facing surface of the stator toward the middle of the first pattern, and

the second magnet is embedded in a second pattern arranged in a form of a bent line or a curve, extending to be more distant from the facing surface of the stator toward the middle of the second pattern, the second pattern being more distant from the facing surface of the stator than the first pattern.

15. The magnet-embedded rotating machine of claim 1 , wherein

the first magnet is embedded in portions of a third pattern arranged in a form of a straight line, a bent line, or a curve, extending to be more distant from the facing surface of the stator toward the middle of the third pattern, and

the second magnet is embedded in the third pattern so as to be positioned closer to the middle of the third pattern compared to the first magnet.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 10, 2023
From: SANGA, YOSHIHITO; ASANO, YOSHINARI
To: DAIKIN INDUSTRIES, LTD.
Reel/Frame 062661/0239 →
Priority Claims (1)
JP 2020-160786 · Sep 25, 2020 · national
Continuity (2)
Continuation PCTJP2021033554 · Sep 13, 2021
Related Publication 20230198325A1 · Jun 22, 2023
References Cited (15)
US 20130127280A1 · Sugimoto · 2013 [cited by examiner]
EP 3561999A1 · 2019 [cited by examiner]
JP 10271722A · 1998 [cited by applicant]
JP 201129293A · 2011 [cited by applicant]
JP 2011223742A · 2011 [cited by applicant]
JP 201351763A · 2013 [cited by applicant]
WO WO2013135377A2 · 2013 [cited by examiner]
WO WO2018051526A1 · 2018 [cited by examiner]
Constantinides Steve: “Understanding and Using Reversible Temperature Coefficients”, 2009 (Jan. 1, 2009), pp. 1-28, XP093173013, URL:https://www.arnoldmagnetics.com/wp-content/uploads/2017/10/Understanding-and-Using-Rev… [cited by examiner]
Machine Translation of WO_2013135377_A2 (Year: 2013). [cited by examiner]
Machine Translation of EP 3561999 A1 (Year: 2019). [cited by examiner]
Machine Translation of WO 2018051526 A1 (Year: 2018). [cited by examiner]
International Search Report of corresponding PCT Application No. PCT/JP2021/033554 dated Nov. 9, 2021. [cited by applicant]
European Search Report of corresponding EP Application No. 21 87 2239.5 dated Jun. 18, 2024. [cited by applicant]
International Preliminary Report of corresponding PCT Application No. PCT/JP2021/033554 dated Apr. 6, 2023. [cited by applicant]