DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Information Disclosure Statement
The information disclosure statements (IDSs) submitted on 10/7/24, 4/8/25 are being considered by the examiner.
Response to Amendment
This office action is in response to preliminary amendment filed on 10/23/24. Regarding the amendment, claims 1-20 are present for examination.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-5, 10-13, and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Verbrugge et al. (US 10,821,591 B2) in view Zhou et al. (CN 103607061 A).
Regarding claim 1, Verbrugge teaches a power tool comprising:
a battery pack interface (160, fig 3) configured to receive a removable and rechargeable battery pack (1000, fig 38); and
a motor (900, fig 26) including:
a stator (905) including a plurality of stator teeth (not label, fig 31) configured to receive a plurality of stator coils (940), and
a rotor (910, fig 34) including:
a plurality of slots (945) configured in a spoke-type configuration, each of the plurality of slots (945) including a magnet housing portion configured to receive one or more magnets (950).
However, Verbrugge does not teach the rotor includes a direct axis inductance and a quadrature axis inductance, wherein the direct axis inductance of the rotor is greater than the quadrature axis inductance of the rotor, and wherein a direct axis current of the motor is positive during operation of the motor when field weakening is not being applied.
Zhou teaches a permanent magnet motor having a rotor (1) includes a direct axis inductance (Ld) and a quadrature axis inductance (Lq), wherein the direct axis inductance (Ld) of the rotor (1) is greater than the quadrature axis inductance (Ld) of the rotor (1, Ld-Lq > 0, para [0061]), and wherein a direct axis current (id) of the motor is positive (id > 0) during operation of the motor when field weakening is not being applied (para [0061]) to reduce the motor cost and ensure permanent magnet motors of same torque production capability (para [0037]).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Verbrugge’s power tool with the rotor includes a direct axis inductance and a quadrature axis inductance, wherein the direct axis inductance of the rotor is greater than the quadrature axis inductance of the rotor, and wherein a direct axis current of the motor is positive during operation of the motor when field weakening is not being applied as taught by Zhou. Doing so would reduce the motor cost and ensure permanent magnet motors of same torque production capability (para [0037]).
Regarding claim 10, Verbrugge teaches a power tool comprising:
a battery pack interface (160, fig 3) configured to receive a removable and rechargeable battery pack (1000, fig 38); and
a motor (900, fig 26) including:
a stator (905) including a plurality of stator teeth (not label, fig 31) configured to receive a plurality of stator coils (940), and
a rotor (910, fig 34) including:
a plurality of slots (945) positioned perpendicular to a radial axis of the rotor (910, fig 34), each of the plurality of slots (945) including a magnet housing portion configured to receive one or more magnets (950).
However, Verbrugge does not teach the rotor includes a direct axis inductance and a quadrature axis inductance, wherein the direct axis inductance of the rotor is greater than the quadrature axis inductance of the rotor, and wherein a direct axis current of the motor is positive during operation of the motor when field weakening is not being applied.
Zhou teaches a permanent magnet motor having a rotor (1) includes a direct axis inductance (Ld) and a quadrature axis inductance (Lq), wherein the direct axis inductance (Ld) of the rotor (1) is greater than the quadrature axis inductance (Ld) of the rotor (1, Ld-Lq > 0, para [0061]), and wherein a direct axis current (id) of the motor is positive (id > 0) during operation of the motor when field weakening is not being applied (para [0061]) to reduce the motor cost and ensure permanent magnet motors of same torque production capability (para [0037]).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Verbrugge’s power tool with the rotor includes a direct axis inductance and a quadrature axis inductance, wherein the direct axis inductance of the rotor is greater than the quadrature axis inductance of the rotor, and wherein a direct axis current of the motor is positive during operation of the motor when field weakening is not being applied as taught by Zhou. Doing so would reduce the motor cost and ensure permanent magnet motors of same torque production capability (para [0037]).
Regarding claims 2 and 11, Verbrugge in view of Zhou teaches the claimed invention as set forth in claims 1 and 10, except for the added limitation of each magnet housing portion includes a centrally-located mid-rib that divides each magnet housing portion into a first section and a second section.
Zhou further teaches the motor having each magnet housing portion includes a centrally-located mid-rib (6) that divides each magnet housing portion into a first section (4) and a second section (5) to reduce the motor cost and ensure permanent magnet motors of same torque production capability (para [0037]).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Verbrugge in view of Zhou’s power tool with each magnet housing portion includes a centrally-located mid-rib that divides each magnet housing portion into a first section and a second section as further taught by Zhou. Doing so would reduce the motor cost and ensure permanent magnet motors of same torque production capability (para [0037]).
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Regarding claims 3 and 12, Verbrugge in view of Zhou teaches the claimed invention as set forth in claims 2 and 11, except for the added limitation of the first section is configured to receive a first magnet and the second section is configured to receive a second magnet.
Zhou further teaches the motor having the first section (4) is configured to receive a first magnet and the second section (5) is configured to receive a second magnet (fig 2) to reduce the motor cost and ensure permanent magnet motors of same torque production capability (para [0037]).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Verbrugge in view of Zhou’s power tool with the first section is configured to receive a first magnet and the second section is configured to receive a second magnet as further taught by Zhou. Doing so would reduce the motor cost and ensure permanent magnet motors of same torque production capability (para [0037]).
Regarding claims 4 and 13, Verbrugge in view of Zhou teaches the claimed invention as set forth in claims 3 and 12, Verbrugge further teaches the rotor (910) includes a total of eight or fewer magnets (4 magnets 950, fig. 34).
Regarding claim 5, Verbrugge in view of Zhou teaches the claimed invention as set forth in claim 1, Verbrugge further teaches the rotor (910) includes a total of four or fewer magnets (4 magnets 950, fig. 34).
Regarding claim 18, Verbrugge teaches a power tool comprising:
a battery pack interface (160, fig 3) configured to receive a removable and rechargeable battery pack (1000, fig 38); and
a motor (900, fig 26) including:
a stator (905) including a plurality of stator teeth (not label, fig 31) configured to receive a plurality of stator coils (940), and
a rotor (910, fig 34) including:
a plurality of slots (945), each of the plurality of slots (945) including a magnet housing portion configured to receive one or more magnets (950).
However, Verbrugge does not teach the plurality of slots configured in pairs to form a V-shaped configuration, each pair of the plurality of slots includes a centrally-located mid-rid positioned between a first slot of the pair and a second slot of the pair, wherein the rotor includes a direct axis inductance and a quadrature axis inductance, wherein the direct axis inductance of the rotor is greater than the quadrature axis inductance of the rotor, and wherein a direct axis current of the motor is positive during operation of the motor when field weakening is not being applied.
Zhou teaches a permanent magnet motor having a rotor (1) includes plurality of slots (fig 2) configured in pairs to form a V-shaped configuration (4-5), each pair of the plurality of slots includes a centrally-located mid-rid (6) positioned between a first slot (4) of the pair and a second slot (5) of the pair, the rotor includes a direct axis inductance (Ld) and a quadrature axis inductance (Lq), wherein the direct axis inductance (Ld) of the rotor (1) is greater than the quadrature axis inductance (Ld) of the rotor (1, Ld-Lq > 0, para [0061]), and wherein a direct axis current (id) of the motor is positive (id > 0) during operation of the motor when field weakening is not being applied (para [0061]) to reduce the motor cost and ensure permanent magnet motors of same torque production capability (para [0037]).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Verbrugge’s power tool with the plurality of slots configured in pairs to form a V-shaped configuration, each pair of the plurality of slots includes a centrally-located mid-rid positioned between a first slot of the pair and a second slot of the pair, wherein the rotor includes a direct axis inductance and a quadrature axis inductance, wherein the direct axis inductance of the rotor is greater than the quadrature axis inductance of the rotor, and wherein a direct axis current of the motor is positive during operation of the motor when field weakening is not being applied as taught by Zhou. Doing so would reduce the motor cost and ensure permanent magnet motors of same torque production capability (para [0037]).
Claim(s) 6-7, 16-17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Verbrugge in view Zhou, further in view of Ionel (US 7,932,658 B2).
Regarding claim 6, Verbrugge in view of Zhou teaches the claimed invention as set forth in claim 1, except for the added limitation of each of the plurality of slots includes an open air gap at an outer circumferential surface of the rotor.
Ionel teaches an interior permanent magnet motor including a rotor (20, fig 3) with a plurality of slot (140) wherein each of the plurality of slots (140) includes an open air gap (170) at an outer circumferential surface of the rotor (20) to reduce the cogging and ripple torque (col 8 ln 8-10).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Verbrugge in view of Zhou’s power tool with each of the plurality of slots includes an open air gap at an outer circumferential surface of the rotor as taught by Ionel. Doing so would reduce the cogging and ripple torque (col 8 ln 8-10).
Regarding claim 7, Verbrugge in view of Zhou teaches the claimed invention as set forth in claim 1, except for the added limitation of the rotor includes a plurality of air gaps positioned between adjacent ones of the plurality of slots.
Ionel teaches an interior permanent magnet motor including a rotor (20, fig 3) with a plurality of slot (140) wherein the rotor includes a plurality of air gaps (80) positioned between adjacent ones of the plurality of slots (140, fig 3) to reduce the cogging and ripple torque (col 8 ln 8-10).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Leembruggen view of Zhou’s power tool with the rotor includes a plurality of air gaps positioned between adjacent ones of the plurality of slots as taught by Ionel. Doing so would reduce the cogging and ripple torque (col 8 ln 8-10).
Regarding claim 16, Verbrugge in view of Zhou teaches the claimed invention as set forth in claim 10, except for the added limitation of the rotor includes a plurality of air gaps positioned on an outer circumferential surface of the rotor.
Ionel teaches an interior permanent magnet motor including a rotor (20, fig 3) with a plurality of slot (140) wherein the rotor (20) includes a plurality of air gaps (170) positioned on an outer circumferential surface of the rotor (20) to reduce the cogging and ripple torque (col 8 ln 8-10).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Leembruggen view of Zhou’s power tool with the rotor includes a plurality of air gaps positioned on an outer circumferential surface of the rotor as taught by Ionel. Doing so would reduce the cogging and ripple torque (col 8 ln 8-10).
Regarding claim 17, Verbrugge in view of Zhou and Ionel teaches the claimed invention as set forth in claim 16, except for the added limitation of the plurality of air gaps are funnel-shaped and each of the plurality of air gaps is located between adjacent slots of the plurality of slots.
Ionel further teaches an interior permanent magnet motor including a rotor (20, fig 3) with a plurality of slot (140) wherein the plurality of air gaps (170) are funnel-shaped (fig 3) and each of the plurality of air gaps (170) is located between adjacent slots of the plurality of slots to reduce the cogging and ripple torque (col 8 ln 8-10).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Leembruggen view of Zhou and Ionel’s power tool with the plurality of air gaps are funnel-shaped and each of the plurality of air gaps is located between adjacent slots of the plurality of slots as further taught by Ionel. Doing so would reduce the cogging and ripple torque (col 8 ln 8-10).
Claim(s) 8-9, 14-15, 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Verbrugge in view Zhou, further in view of Gracia et al. (US 2013/0270949 A1).
Regarding claims 8-9, 14-15, and 19-20, Verbrugge in view of Zhou teaches the claimed invention as set forth in claims 1, 10, and 18, except for the added limitation of
the rotor includes a magnet volume of less than 3,000 millimeters cubed (“mm3”) (claims 8, 14, and 19);
or the rotor includes a magnet volume of less than 1,500 millimeters cubed (“mm3”) (claims 9 and 20);
or the rotor includes a magnet volume of less than 2,500 millimeters cubed (“mm3”) (claim 15).
Gracia teaches a permanent magnet electric machine having a rotor includes a magnet volume more than 1 millimeters cubed (“mm3”), preferably 10mm3 (para [0015]) to increase probability of demagnetization of the permanent magnet (para [0017]).
Thus, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Leembruggen view of Zhou and Ionel’s power tool with the rotor includes a magnet volume of less than 3,000 millimeters cubed (“mm3”) (claims 8, 14, and 19); or the rotor includes a magnet volume of less than 1,500 millimeters cubed (“mm3”) (claims 9 and 20); or the rotor includes a magnet volume of less than 2,500 millimeters cubed (“mm3”) (claim 15) as taught by Gracia. Doing so would increase probability of demagnetization of the permanent magnet (para [0017]).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Hung et al. (US 11,682,937 B2) teaches a rotor structure includes a rotor body and a plurality of magnets. The rotor body has a plurality of surrounding magnet-setting areas, and each magnet setting area has a first magnet slot and a second magnet slot symmetrically arranged to a centripetal axis. A first outer end of the first magnet slot and a second outer end of the second magnet slot are close to the centripetal axis and rotor's outer edge. A first outer end of the first magnet slot and a second outer end of the second magnet slot are distant to the centripetal axis and rotor's outer edge. The outer edge has a plurality of notches intersected by the corresponding centripetal axes. The magnets are respectively fixed to the first magnet slots and the second magnet slots of the magnet-setting areas.
Krizan et al. (US 11,575,285 B2) teaches an electric machine includes a stator and a rotor. The stator defines a central orifice and has an inner diameter. The rotor has an outer diameter and is disposed within the stator. An airgap is defined between inner diameter and the outer diameter. The rotor defines a plurality of cavities. The rotor has magnets disposed within each of the cavities. The magnets define a plurality of pole arc angles. Each pole arc angle is centered about a D-axis. The rotor has an outer periphery. The outer periphery forms smooth spline curves positioned within each pole arc angle. The smooth spline curves deviate radially inward relative to the outer diameter.
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/LEDA T PHAM/ Primary Examiner, Art Unit 2834
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