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 .
Response to Arguments
Applicant's arguments filed June 5, 2026 with respect to the rejection of claims 1 and 2 under 35 U.S.C. 103 over Handa in view of Morita have been fully considered and are persuasive. Upon further review of Morita, the annular inner circumferential wall(97) extends from near the inner circumferential end of the end face of the core block(88)(¶[0051], Figs. 3, 5); the inner diameter of the annular inner circumferential wall(97) is therefore not smaller than the outer diameter of the rotor(15), and the annular inner circumferential wall(97) does not radially overlap the rotor(15). The rejections of claims 1-4, 7, 8, 17, and 19-23 over Handa in view of Morita are withdrawn. However, upon further consideration, a new ground of rejection is made in view of newly discovered prior art to Vanhee (US11876434), as set forth below. Because the new ground of rejection was not necessitated by amendment, this action is made non-final.
Applicant's arguments with respect to claim 22 have been fully considered and are persuasive. Handa expressly teaches that the partition parts(42b, 43b) and mold members(33a, 33b) are sealed to separate the first space(S1), in which the rotor(20) is arranged, from the second space(S2), thereby preventing the cooling oil(OL) from entering the air gap(G)(¶[0034]); the rotor of Handa is accordingly not exposed to and in direct contact with the coolant. The rejection of claim 22 over Handa in view of Morita is withdrawn. A new ground of rejection over Vanhee, which expressly teaches coolant flowing through the radial air gap in contact with the rotor core, is set forth below.
Applicant's arguments with respect to the rejection of claim 5 over Handa in view of Morita and Arnold have been fully considered and are persuasive in view of the amendment to claim 5. The deflector(39) of Arnold is disposed radially between the outer stator shell(13) and the end turns(12) of the windings and is not disposed in axial alignment with the airgap defined radially between the stator core(5) and the rotor(19)(Arnold, 3:55-4:15, Figs. 5-7). The rejection of claim 5 is withdrawn, and claim 5 is indicated as containing allowable subject matter below.
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.
Claim(s) 1-4, 7-8, 20, and 22 is/are rejected under 35 U.S.C 103 as being unpatentable over VANHEE(US11876434B2) in view of MORITA(JP2009201217A).
Vanhee (US 11,876,434) was filed in the United States on September 3, 2021 as Application No. 17/446,933 and was published as US 2023/0071523 on March 9, 2023. Although the publication date and the issue date of Vanhee are after the effective filing date of the claimed invention (September 6, 2021, the filing date of EP 21195002 to which the present application properly claims priority), Vanhee qualifies as prior art under 35 U.S.C. 102(a)(2) because Vanhee names another inventor and was effectively filed on September 3, 2021, before the effective filing date of the claimed invention.
Regarding claim 1, Vanhee teaches a direct cooled electric motor(100) for a traction drive of an electric vehicle(integrated into a battery electric vehicle)(col. 3, l. 62 - col. 4, l. 1),
adapted to be cooled by a coolant(coolant oil),
the electric motor comprising: a housing(102) receiving a stator core(104)(col. 4, ll. 14-16, Figs. 1-2),
the stator core including a steel lamination stack(laminated steel stator)(col. 9, ll. 8-13),
a rotor(112, rotor core 114) arranged to rotate radially inside the stator core(104)(col. 4, ll. 25-29; col. 5, ll. 38-44, Figs. 1-2),
and a plurality of windings(hairpin wires with end windings 106, 201)(col. 4, ll. 16-21; col. 6, ll. 49-56, Fig. 2) extending axially through the stator core(104) and axially beyond a plurality of axial ends(202, 203) of the stator core,
and at least one ring-shaped end fiber(sealing plate 211; ring 213);
wherein the at least one end fiber(211) is arranged at a respective axial end(203) of the plurality of axial ends of the stator core(104), extends in a circumferential direction and in a radial direction over the respective axial end of the stator core(coupled to the stator in circumferential face-sharing contact at the axial end face and extending radially therefrom; overmolded onto the stator)(col. 6, ll. 26-38, Figs. 2, 3A);
and wherein an inner diameter of the at least one end fiber is smaller than an outer diameter of the rotor(the sealing plate 211 and ring 213 extend radially inward to central openings at the rotor shaft 116 and circumferentially cover the rotor core 114 at the axial ends, such that the inner diameter of each is at the rotor shaft, radially inside the outer diameter of the rotor core)(col. 5, ll. 46-58; col. 6, ll. 56-59; Figs. 2, 3A-3C).
Vanhee does not explicitly teach a plurality of winding apertures arranged circumferentially around the at least one end fiber wherein the plurality of windings extend through the plurality of winding apertures.
However, Morita teaches a ring-shaped insulating end structure(insulator rubbers 90 collectively forming a substantially cylindrical annular structure when all core blocks 88 are assembled)(¶[0051], Figs. 12-16) arranged at an axial end of a stator core(88) including a plurality of winding apertures arranged circumferentially(the openings of the rectangular annular insulators 90, arranged circumferentially with the core blocks 88 butted together in an annular shape)(¶[0048]-[0049], Figs. 10-13) wherein the plurality of windings extend through the plurality of winding apertures(the stator coils 91 are wound through the insulators 90 attached to the core blocks so as to surround the area passing through the coil housing slots 89)(¶[0048]).
Morita is considered to be analogous to the claimed invention of Vanhee because they are in the same field of electric machines. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have modified the end fiber of Vanhee to include a plurality of winding apertures arranged circumferentially around the end fiber, wherein the plurality of windings extend through the plurality of winding apertures, as taught by Morita. One would be motivated to do this in order to electrically insulate and mechanically support the stator coils where they exit the axial end of the stator core, as taught by the elastic insulating member of Morita(¶[0048]), which is compatible with the electrically insulating end structure of Vanhee(bracket 217 formed of a non-magnetic, electrically insulating material)(col. 5, ll. 28-33), yielding the predictable result of a stationary insulating end member that both guides the windings and covers the radial air gap. The combination of familiar elements according to known methods that yields predictable results is obvious. KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007).
Regarding claim 2/1, Vanhee in view of Morita teaches the direct cooled electric motor of claim 1.
Vanhee further teaches wherein the at least one end fiber(211, 213) has a radial inner edge(central opening at the rotor shaft 116) and, at the radial inner edge, radially overlaps the rotor(the ring 213 and the sealing plate 211 together circumferentially cover the rotor core 114 at the first end 202 and the second end 203, extending radially inward past the outer diameter of the rotor core to the rotor shaft)(col. 6, ll. 56-59; Figs. 2, 3A-3C).
Regarding claim 3/1, Vanhee in view of Morita teaches the direct cooled electric motor of claim 1.
Vanhee teaches an end fiber axial clearance between the at least one end fiber and the rotor(first conduit 230 formed between the ring 213 and the first balancing plate 120 of the rotor; second conduit 240 formed between the sealing plate 211 and the second balancing plate 204, the width of each conduit being significantly smaller than the width of the respective end member)(col. 6, ll. 38-48, Figs. 3A-3C).
Vanhee does not explicitly teach wherein the end fiber axial clearance is smaller than half of a difference between the outer diameter of the rotor and the inner diameter of the at least one end fiber.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the end fiber axial clearance between the at least one end fiber and the rotor be smaller than half of the difference between the outer diameter of the rotor and the inner diameter of the at least one end fiber, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 220 F.2d 454, 456 (CCPA 1955). One would be motivated to do this in order to avoid mechanical interference between the rotor and the end fiber while limiting the amount of coolant entering the radial air gap through the clearance.
Regarding claim 4/1, Vanhee in view of Morita teaches the direct cooled electric motor of claim 1.
Vanhee teaches an end fiber axial clearance between the at least one end fiber and the rotor(conduits 230, 240 between the end members and the balancing plates of the rotor)(col. 6, ll. 38-48, Figs. 3A-3C).
Vanhee does not explicitly teach wherein the end fiber axial clearance is 0.3mm to 15mm.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the end fiber axial clearance between the at least one end fiber and the rotor be 0.3mm to 15mm, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 220 F.2d 454, 456 (CCPA 1955). One would be motivated to do this in order to avoid mechanical interference between the rotor and the end fiber while limiting the amount of coolant entering the radial air gap through the clearance.
Regarding claim 7/1, Vanhee in view of Morita teaches the direct cooled electric motor of claim 1.
Vanhee teaches a radial interface between a radially inner edge of the at least one end fiber and the rotor(first dynamic seal 215 attached to the inner circumference of the ring 213 in contact with the first balancing plate 120 of the rotor)(col. 5, l. 58 - col. 6, l. 13, Fig. 3C) and an end fiber axial clearance(conduits 230, 240)(col. 6, ll. 38-48).
Vanhee does not explicitly teach wherein an end fiber radial clearance between the radially inner edge of the at least one end fiber and the rotor is one of equal to and smaller than the end fiber axial clearance.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the end fiber radial clearance be one of equal to and smaller than the end fiber axial clearance, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 220 F.2d 454, 456 (CCPA 1955). One would be motivated to do this in order to avoid mechanical interference between the rotating and stationary parts while limiting coolant flow into the radial air gap.
Regarding claim 8/1, Vanhee in view of Morita teaches the direct cooled electric motor of claim 1.
Vanhee teaches a radial interface between a radially inner edge of the at least one end fiber and the rotor(first dynamic seal 215 at the inner circumference of the ring 213 in contact with the first balancing plate 120)(col. 5, l. 58 - col. 6, l. 13, Fig. 3C).
Vanhee does not explicitly teach wherein an end fiber radial clearance between the radially inner edge of the at least one end fiber and the rotor is 0.3mm to 15mm.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the end fiber radial clearance between the radially inner edge of the at least one end fiber and the rotor be 0.3mm to 15mm, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 220 F.2d 454, 456 (CCPA 1955). One would be motivated to do this in order to avoid mechanical interference between the rotating and stationary parts while limiting coolant flow into the radial air gap.
Regarding claim 20/1, Vanhee in view of Morita teaches the direct cooled electric motor of claim 1.
The combination does not explicitly teach wherein the at least one end fiber is structured as a standalone injection-molded component and at least a main body of the at least one end fiber is composed of polyphenylene sulfide (PPS) material.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the at least one end fiber be structured as a standalone injection-molded component with at least a main body composed of polyphenylene sulfide (PPS) material, since it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416. One would be motivated to do this in order to provide an electrically insulating end fiber resistant to elevated temperature and to chemical attack by the coolant.
Regarding claim 22/1, Vanhee in view of Morita teaches the direct cooled electric motor of claim 1.
Vanhee further teaches wherein the stator core(104), the rotor(112, rotor core 114), the plurality of windings(end windings 106, 201), and the at least one end fiber(211, 213) are exposed to and are in direct contact with the coolant(coolant oil flows through the radial air gap 250 between the stator 104 and the rotor core 114, a small amount of oil being tolerated in the radial air gap to maintain the cooling properties of the oil, and the liquid cooling system 122 circulates coolant oil throughout the cavity 270 of the housing over the components contained therein, including the end windings and the end members)(col. 3, ll. 40-46; col. 9, ll. 20-33; col. 4, ll. 60-67, Figs. 2, 3A-3C).
9. Claim(s) 13-14 is/are rejected under 35 U.S.C 103 as being unpatentable over VANHEE(US11876434B2) in view of MORITA(JP2009201217A) and further in view of KROL(US2017353064A1).
Regarding claim 13/1, Vanhee in view of Morita teaches the direct cooled electric motor of claim 1.
The combination does not explicitly teach wherein the at least one end fiber further includes a recess forming a coolant passage between the at least one end fiber and the stator core; the end members of Vanhee route coolant through intake holes rather than through a recess formed against the stator core.
However, Krol teaches an arrangement for cooling an axial end region of a stator wherein a stationary annular member(annular chamber 12) arranged at the axial end region(11) of the stator(2) includes a recess(the radially inward open cavity of the annular chamber 12) forming a coolant passage between the member and the stator(the annular chamber is at least partially open radially inward in the direction of the axial end region, is sealed with respect to the axial end region, and is connected in communicating fashion to the cooling ducts 3)(¶[0027], Fig. 1).
Krol does not explicitly teach wherein a width of the coolant passage in an axial direction is one of equal to and smaller than an end fiber axial clearance between the at least one end fiber and the rotor.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the width of the coolant passage in the axial direction be one of equal to and smaller than the end fiber axial clearance between the at least one end fiber and the rotor, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 220 F.2d 454, 456 (CCPA 1955).
Krol is considered to be analogous to the claimed invention because they are in the same field of electric machines. One would be motivated to add the teachings of Krol in order to cool the axial end region of the stator to a greater extent than the remainder of the stator(Krol, ¶[0007]), thereby permitting increased machine output. KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007).
Regarding claim 14/13, Vanhee in view of Morita and Krol teaches the direct cooled electric motor of claim 13.
The combination does not explicitly teach wherein the width of the coolant passage in the axial direction is 0.3mm to 15mm.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the width of the coolant passage in the axial direction be 0.3mm to 15mm, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 220 F.2d 454, 456 (CCPA 1955). One would be motivated to do this in order to effectively increase stator end cooling while limiting coolant intrusion into the rotor airgap to increase efficiency.
10. Claim(s) 21 is/are rejected under 35 U.S.C 103 as being unpatentable over VANHEE(US11876434B2) in view of MORITA(JP2009201217A) and further in view of REICHERT(US2020295628A1).
Regarding claim 21/1, Vanhee in view of Morita teaches the direct cooled electric motor of claim 1.
Vanhee further teaches wherein the at least one end fiber(211) is a portion of a stator core overmolding structure(the sealing plate 211 may be overmolded onto the stator 104 at the second end 203)(col. 6, ll. 33-38).
Vanhee does not explicitly teach the overmolding structure composed of a thermoset material; Vanhee is silent as to the material of the sealing plate.
However, Reichert teaches a stator-end fluid conducting element composed of a thermosetting plastic material(¶[0014]). Reichert is considered to be analogous to the claimed invention because they are in the same field of electric machines. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have the stator core overmolding structure of Vanhee in view of Morita be composed of a thermoset material, as taught by Reichert. One would be motivated to do this in order to provide a heat-resistant, non-ferromagnetic end structure that prevents the development of induced heat at the stator end(Reichert, ¶[0014]). KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007).
Allowable Subject Matter
Claims 24 and 25 are allowed.
Regarding claim 24, the closest prior art of Vanhee, Morita, Reichert, Handa, and Krol teaches every limitation except "wherein the at least one end fiber forms part of an airgap labyrinth seal; and wherein a plurality of rotational counterparts of the labyrinth seal are provided by the rotor". Vanhee names a labyrinth seal among alternatives for its dynamic seals(col. 6, ll. 1-13) but discloses no labyrinth structure and does not disclose a plurality of rotational counterparts of the labyrinth seal provided by the rotor; the prior art of record neither anticipates nor renders obvious this limitation in combination with the remaining limitations of claim 24.
Regarding claim 25, the closest prior art of Vanhee, Morita, Reichert, Handa, and Krol teaches every limitation except "wherein the rotor includes an impeller for inducing coolant flow past the plurality of windings and/or through at least one cooling channel in the stator core; wherein the impeller includes a plurality of blades and a lip and/or a groove; and wherein the lip and/or the groove forms part of an airgap labyrinth seal". The prior art of record does not disclose a rotor-mounted impeller having blades and a lip and/or groove forming part of an airgap labyrinth seal; this limitation is neither anticipated nor rendered obvious in combination with the remaining limitations of claim 25.
12. Claims 5, 6, 9, 10-12, 15, 16, 17, and 18 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Regarding claim 5/1, the prior art of record does not teach the limitation, "the airgap flow deflector disposed in axial alignment with at least a portion of an airgap defined radially between the stator core and rotor" together with the recited at least one inclined surface, in combination with the limitations of the base claim. The deflector(39) of Arnold is disposed at a radially outer position between the stator shell(13) and the end turns(12); the end members of Vanhee are not disclosed as having an inclined surface in the region axially aligned with the radial air gap; and the fluid repelling surface of Reichert is disposed at the central through-opening for the rotor shaft rather than in axial alignment with the airgap.
Regarding claim 6/1, the prior art of record does not teach the limitation, "the airgap flow deflector converges towards the rotor to the inner diameter of the at least one end fiber", in combination with the limitations of the base claim.
Regarding claim 9/22, the prior art of record does not teach the limitation, "the at least one end fiber forms part of an airgap labyrinth seal, and a plurality of rotational counterparts of the labyrinth seal are provided by the rotor", in combination with the limitations of the base claim and the intervening claim.
Regarding claim 10/1, the prior art of record does not teach the limitation, "in an axial plane containing a rotational axis of the rotor, a deflection angle of the at least one deflection surface between a plane extending perpendicular to the rotational axis of the rotor and the at least one deflection surface is 0° to 90°" together with the recited inclined and/or chamfered deflection surface for deflecting the coolant away from a plurality of rotating parts, in combination with the limitations of the base claim. Claims 11 and 12 are objected to for being dependent on claim 10.
Regarding claim 15/13, the prior art of record does not teach the limitation, "the stator core further includes at least two cooling channels extending axially through the stator core; and the recess of the coolant passage fluidly connects (i) at least two of the at least two cooling channels with each other and/or (ii) at least one of the at least two cooling channels with a coolant outlet and/or a cooling inlet", in combination with the limitations of the base claim and the intervening claim. The cooling ducts(3) of Krol extend radially, not axially, through the stator plate stack(¶[0024], [0027], Fig. 1), and the prior art of record does not teach axially extending stator cooling channels fluidly connected by a recess of a coolant passage of the at least one end fiber.
Regarding claim 16/15, the prior art of record does not teach the limitation, "wherein the at least two cooling channels are fluidly connected in series and the coolant passage fluidly connects the at least two cooling channels such that the coolant is flowable in opposite directions axially through the stator core", in combination with the limitations of the base claim and the intervening claims.
Regarding claim 17/1, the prior art of record does not teach the limitation, "wherein the at least one end fiber further includes at least one radially outer contact surface contacting the housing", in combination with the limitations of the base claim. The end members of Vanhee are coupled to the stator(104) and to the bracket(217) rather than to the housing.
Regarding claim 18/22, the prior art of record does not teach the limitation, "the impeller includes a plurality of blades and a lip and/or a groove; and the lip and/or the groove forms part of an airgap labyrinth seal", in combination with the limitations of the base claim and the intervening claim.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant’s disclosure:
Neudorfer (EP2429065A2) teaches a permanent-magnet electric machine in which the air gap between the stator and the rotor is sealed against the ingress of contaminants at the axial ends of the machine.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MOHAMMED QURESHI whose telephone number is (571)-272-8310. The examiner can normally be reached on 8:30 AM - 6:00 PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Tulsidas Patel can be reached on 571-272-2098. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/MOHAMMED AHMED QURESHI/Examiner, Art Unit 2834
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