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 statement (IDS) submitted on 11/14/2025 is being considered by the examiner.
Response to Arguments
Applicant’s arguments, see page 9, filed 10/08/2025, with respect to Objections to Specification and Rejections under 35 USC 112 have been fully considered and are persuasive. The Objections to the Specification and Rejections under 35 USC 112 of claim 7 have been withdrawn.
Applicant’s arguments with respect to claims 1-4, 6-33, and 35 as rejected under Shcherbakov have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-2, 10-11, 15-33, and 35 are rejected under 35 U.S.C. 103 as being unpatentable over SHCHERBAKOV (WO 2019235953; previously cited) in view of DAVISON (US 20150076971).
Regarding claim 1, SHCHERBAKOV discloses an electric machine comprising:
a rotor [1] mounted to rotate about an axis (unlabeled; see pp 4-5, lines 22-04 and Fig. 2), the rotor [1] comprising a shell [holder 4] (see Fig. 2) shaped to provide a toroidal bore (see p 3, lines 21-22) centered on the axis (see Fig. 2) and having a slit extending circumferentially around the rotor (unlabeled; see Figs. 1a-c and 2), the slit penetrating through the shell into the bore (see Fig. 1a-c), the rotor comprising a permanent ring magnet [magnet assembly 3] around the rotor in the bore (see p 5, lines 7-14 and Fig. 4); and
a stator [2] supported in the bore by one or more supports [stator connecting pins 22] extending through the slit of the rotor (see p 5, lines 25-28 and Fig. 6), the stator [2] carrying a plurality of windings [23] spaced apart around the bore (see Fig. 7).
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However, SHCHERBAKOV does not disclose the plurality of circumferentially spaced-apart permanent ring magnets.
DAVISON discloses an electric machine with a plurality of circumferentially spaced-apart permanent ring magnets (4) around a toroidal bore (see Fig. 1).
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DAVISON
It 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 to provide the rotor of SHCHERBAKOV with a plurality of circumferentially spaced-apart permanent ring magnets around the toroidal bore in the rotor, similar to the magnets in the stator of DAVISON.
A person having ordinary skill in the art to which the claimed invention pertains would have been motivated to make such modification in order to increase the surface area of the magnetic field and the rotational force (see DAVISON para [0003])
Regarding claim 2 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
DAVISON discloses the permanent ring magnets are arranged to provide magnetic poles and wherein the magnetic poles each extend in a poloidal direction around an interior surface of the bore from a location near a first edge of the slit to a location near a second edge of the slit (see Fig. 1).
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Regarding claim 10 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
SHCHERBAKOV discloses a plurality of permanent magnets [3] is arranged to form one or more Halbach arrays oriented to concentrate magnetic field within the toroidal bore of the rotor. (See p 5, lines 7-14 and Fig. 4)
Regarding claim 11 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 10 wherein
DAVISON discloses the permanent magnets [4] comprise ring magnets that have gaps aligned with the slit (see Fig. 1).
Regarding claim 15 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 10 wherein
SHCHERBAKOV discloses the shell [holder 4] comprises a continuous layer of a ferromagnetic material (see p 2, line 21) backing the magnets on a side of the magnets away from the bore of the rotor (see Figs. 2-3).
Regarding claim 16 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
SHCHERBAKOV discloses a width of the slit is not more than one third of a circumference in the poloidal direction of an inner surface of the rotor. (See the width in annotated Fig. 1c, below.)
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Regarding claim 17 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
SHCHERBAKOV discloses the slit spans an angle relative to a centroid of a cross-sectional of the bore in a plane that includes the axis that is not more than 60 degrees. (See the axis and the angle of the slit in annotated Fig. 1c, below.)
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Regarding claim 18 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
SHCHERBAKOV discloses a ratio of an area of the slit to an area of a toroidal surface on which an inner surface of the rotor lies is not more than 1:12. (See the area of the inner surface of the rotor in annotated Fig. 1c, below.)
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Regarding claim 19 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
SHCHERBAKOV discloses the stator [2] comprises one or more cooling channels [6] and the electric machine comprises one or more conduits [20,21] that extend through the slit and are connected to supply cooling fluid to the one or more cooling channels [6] and/or to remove the cooling fluid from the one or more cooling channels. (See p 5, lines 22-28 and Figs. 2 and 6)
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Regarding claim 20 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 19 wherein
SHCHERBAKOV discloses the one or more cooling channels [6] extend toroidally around the stator (see pp 4-5, lines 22-04 and Fig. 2).
Regarding claim 21 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 20 wherein
SHCHERBAKOV discloses the one or more cooling channels [6] extend around the stator on a centerline of the stator. (see pp 4, line 22-p 5, line 4 and Fig. 2).
Regarding claim 22 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
SHCHERBAKOV discloses the stator [2] comprises a core [5] of a ferromagnetic material (see p 3, lines 4-8) and the windings [23] comprise toroidal windings wound around the core at locations spaced apart along the core (see p 5, line 22-p 6, line 6 and Figs. 6-7)
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Regarding claim 23 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 22 wherein
SHCHERBAKOV discloses the toroidal windings comprise integral or fractional windings (the ratios of magnets to windings are fractional, either 2:6 or 4:6; see claims 3 and 4).
Regarding claim 24 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 22 wherein
SHCHERBAKOV discloses the core [5] comprises ribs [unlabeled; defined between grooves 25] of the ferromagnetic material located between adjacent ones of the windings (see p 6, lines 12-14), the ribs extending around the core in the poloidal direction (see Figs. 10b-d).
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Regarding claim 25 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 24 wherein
SHCHERBAKOV discloses the ribs are interrupted (by grooves [25], coolant elements [19], and stator connecting pins [22]) at the location where the ribs cross the slit (see Figs. 2, 6, and 10b-d).
Regarding claim 26 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 25 wherein
SHCHERBAKOV discloses the ribs are interrupted by V-shaped cutouts [grooves 25] that are aligned with the slit (grooves [25] extend around the core [5] in the poloidal direction and align with the slit where the core is aligned with the slit; see Figs. 2, 6, and 10b-d).
Regarding claim 27 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 24 wherein
SHCHERBAKOV discloses outer surfaces of the toroidal windings [23] and outer surfaces of the ribs are aligned with one another. (see p 6, lines 12-14 and Fig. 10b-d)
Regarding claim 28 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 24 wherein
SHCHERBAKOV discloses outer surfaces of the toroidal windings [23] are recessed toward the core [5] relative to outer surfaces of the ribs. (The depths of the grooves [25] may vary, recessing the outer surfaces of the windings toward the core; see p 6, lines 12-14 and Fig. 10b-d.)
Regarding claim 29 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 comprising
SHCHERBAKOV discloses a casing [8,9] shaped to conform with an outer surface of the rotor [1] and positioned to provide a clearance gap between the casing [8,9] and the rotor [1] (see Figs. 1a-c and 2).
Regarding claim 30 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 29 comprising
SHCHERBAKOV discloses cooling channels [6,19,20,21] in the casing [8,9], the cooling channels located adjacent to the rotor [1] and connectible to carry cooling fluid (See p 5, lines 22-28 and Figs. 2 and 6).
Regarding claim 31 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
SHCHERBAKOV discloses the one or more supports [22] comprise electrical conductors connected to carry electrical power to or from the stator [2] (see p 6, lines 26-28 and Figs. 6-9).
Regarding claim 32 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
the stator [2] comprises spokes [pins 22] located between the windings and extending radially away from the stator [2] (see p 5, lines 25-28 and Fig. 6).
Regarding claim 33 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
SHCHERBAKOV discloses a cross section of the bore in a plane that includes the axis is circular or elliptical (see Figs. 1a-c).
Regarding claim 35 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1 wherein
SHCHERBAKOV discloses the slit is:
on a side of the rotor facing away from the axis (see Figs. 1a-c);
on a side of the rotor facing toward the axis; or
on a side of the rotor facing parallel to the axis.
Claims 3-4, 6-9, and 12-14 are rejected under 35 U.S.C. 103 as being unpatentable over SHCHERBAKOV in view of DAVISON and further in view of KLASSEN (US 9742227; previously cited).
Regarding claim 3 SHCHERBAKOV in view of DAVISON teaches the electric machine according to claim 1.
However, SHCHERBAKOV in view of DAVISON does not teach adjacent ones of the permanent ring magnets are separated by a section of a ferromagnetic material that provides one of a plurality of magnetic poles.
KLASSEN teaches an electric machine with a rotor comprising a plurality of circumferentially spaced-apart permanent magnets [3302] wherein adjacent ones of the magnets are separated by a section of a ferromagnetic material [rotor posts 3304] that provides one of a plurality of magnetic poles. (see col. 60, lines 50-54 and Figs. 144-145)
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It 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 to provide the rotor of SHCHERBAKOV in view of DAVISON with adjacent ones of the magnets separated by a section of a ferromagnetic material that provides one of the poles as taught by KLASSEN.
A person having ordinary skill in the art to which the claimed invention pertains would have been motivated to make such modification in order to, as KLASSEN teaches “lower cost due to half the number of magnets, lower tolerance stackup due to being able to connect all of the steel triangle parts into a single backiron component, and better securing of the permanent magnets due to them being magnetically attracted to the soft magnetic material rotor backiron” (col. 27, lines 61-67 of Klassen).
Regarding claim 4 SHCHERBAKOV in view of DAVISON and further in view of KLASSEN teaches the electric machine according to claim 3 wherein
SHCHERBAKOV teaches the permanent magnets are magnetized in a direction that is tangential to a diameter of the rotor and wherein circumferentially adjacent ones of the permanent ring magnets are polarized in opposing directions (see Fig. 5)
Regarding claim 6 SHCHERBAKOV in view of DAVISON and further in view of KLASSEN teaches the electric machine according to claim 3 wherein
SHCHERBAKOV discloses a ferromagnetic material comprising a soft magnetic composite (SMC) (see claim 14).
Regarding claim 12 SHCHERBAKOV in view of DAVISON and further in view of KLASSEN teaches the electric machine according to claim 6 wherein
SHCHERBAKOV teaches the plurality of permanent ring magnets are magnetized in a direction that is radial to the toroidal bore of the rotor (see Fig. 5).
Regarding claim 13 SHCHERBAKOV in view of DAVISON and further in view of KLASSEN teaches the electric machine according to claim 12 wherein
SHCHERBAKOV teaches polarities of circumferentially adjacent ones of the magnets alternate (see Fig. 5).
Regarding claim 14 SHCHERBAKOV in view of DAVISON and further in view of KLASSEN the electric machine according to claim 12 wherein
DAVISON teaches the permanent ring magnets have gaps aligned with the slit (see Figs. 1).
Regarding claim 7 SHCHERBAKOV in view of DAVISON and further in view of KLASSEN teaches the electric machine according to claim 3 wherein
KLASSEN discloses an outer surface of the ferromagnetic material [rotor posts 3304] is shaped to follow a contour of substantially constant magnetic flux density. (See col. 63, lines 12-17 and Figs. 141-143: “the present device provides a high strength, high mechanical rigidity concentrated flux rotor by the use of a unified soft magnetic material post array and back iron and it does this with minimal reduction of the air gap flux density through the use of increased magnet depth and post height.” Emphasis added. The “unified soft magnetic material post array” provides a surface with a contour, as broadly claimed(see Fig. 143))
KLASSEN teaches that arrangements of different post heights and intervals can be used in a rotor to produce different average flux densities (see col 88, lines 5-37), making the rotor magnet and post dimensions result effective variables, in order to improve flux density distribution (see col 88, lines 5-37).
Thus, it 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 to arrange the rotor geometry according to the claimed configuration to place the average flux density between the claimed range of +/- 20%.
A person having ordinary skill in the art to which the claimed invention pertains would have been motivated to make such modification in order to improve the flux density distribution, as taught by KLASSEN (see col 88, lines 5-37), and since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art (See In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980)).
Regarding claim 8 SHCHERBAKOV in view of DAVISON and further in view of KLASSEN teaches the electric machine according to claim 3 wherein
KLASSEN discloses normals to an outer surface of the ferromagnetic material are generally parallel to a gradient of flux density in the ferromagnetic material adjacent to the outer surface of the ferromagnetic material. (See col. 63, lines 19-35 and Figs. 142-143)
Regarding claim 9 SHCHERBAKOV in view of DAVISON and further in view of KLASSEN teaches the electric machine according to claim 3 wherein
KLASSEN discloses a surface of the ferromagnetic material on an outside of the rotor is formed with a cut out or groove that extends in the poloidal direction. (The cutout or groove spans between radial holes [3034], see annotated Fig. 133, below)
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Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. DE-19639670-A1 LANGE discloses a rotor with a plurality of ring-shaped magnets 30; WO-2019043692-A1 HAITIN discloses a toroidal rotor (see Fig. 5A-5B).
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JUSTIN STEFANON whose telephone number is (703)756-4648. The examiner can normally be reached Monday - Thursday and alternate Fridays 8AM - 5PM EDT.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Oluseye Iwarere can be reached at (571) 270-5112. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JUSTIN STEFANON/Examiner, Art Unit 2834
/OLUSEYE IWARERE/Supervisory Patent Examiner, Art Unit 2834