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 .
Status of Claims
Claims 1–15 are pending in the application. Claims 1–15 are rejected. Claims 10 and 15 contain allowable subject matter, as set forth below. This action is non-final.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the “fluid inlet located at the outer circumference of the stator” recited in claim 6 must be shown or the feature(s) canceled from the claim(s). The specification states that “cooling fluid is supplied to the cold channel 113 via a supply port, the latter not being shown on the figures” (specification, paragraph [56]). No new matter should be entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1–15 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites the limitation “the upper side of the coils”. There is insufficient antecedent basis for this limitation in the claim. Claims 2–15 are rejected by virtue of their dependence from claim 1.
Claim 6 recites the limitations “the outer circumference” and “the inner circumference of the stator”; claim 7 recites the limitations “the outer” and “the inner circumference of the stator”; and claim 14 recites the limitation “the outer towards the inner circumference of the stator”. There is insufficient antecedent basis for these limitations in the respective claims. Claims 8–11 are further rejected by virtue of their dependence from claim 7 and claim 15 is further rejected by virtue of its dependence from claim 14.
Claims 7 and 14 each recite “ending in the spraying element”. Claim 1 recites “one or more spraying elements”; it is unclear which of the one or more spraying elements is being referenced.
Claim 15 recites “running through the material of a wall, the wall positioned between adjacent stator elements” and separately recites “the stator comprises at least one wall, the wall being positioned between two adjacent stator elements”. It is unclear whether “a wall” and the “at least one wall” refer to the same wall or to distinct walls. Claim 15 further recites the limitation that the radial portion is provided as a channel running through the material of the first cover or running through the material of the wall in two separate places, rendering the metes and bounds of the claim unclear.
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.
Claims 1–9 and 11–14 are rejected under 35 U.S.C. 103 as being unpatentable over Leijnen (EP 3 764 526 A1) in view of Yao (US 2021/0288554 A1).
Regarding claim 1, Leijnen teaches an axial flux machine, comprising a stator and a rotor having a central axis in axial direction corresponding to the rotational axis of the axial flux machine(stator 100 for an axial flux machine; central axis 103 corresponding to the rotational axis; rotor and stator coaxially arranged) (¶[0002]–[0003]; ¶[0047]; ¶[0050]; Fig. 1),
the stator comprises a plurality of stator elements enclosed by a stator housing, any of the stator elements comprising a coil wound around a core(symmetrically arranged stator elements 105, each comprising ferromagnetic core 500 and turns 501–504 forming a coil wound around the core; elements enclosed by outer structure 101, inner structure 102, and annular covers 401) (¶[0012]; ¶[0050], Figs. 1–2, 5; ¶[0039]–[0040]; ¶[0065], Fig. 4),
the stator housing comprising a first cover, the first cover having an internal side facing the upper side of the coils and an external side facing the air gap(annular cover 401 positioned at both sides of the stator, sealing the outside surfaces thereof and coupled to the guiding walls; the internal side of the cover 401 lies directly over the turns of the coils, and the external side faces outwardly of the stator, toward the rotor when mounted in the axial flux machine) (¶[0039]–[0040]; ¶[0065], Figs. 4, 9A; ¶[0003]; ¶[0047]).
Leijnen does not explicitly teach the first rotor disk comprising magnets located in an annular zone facing an air gap, nor one or more spraying elements provided on the first cover and one or more cooling channels adapted to guide a cooling fluid under pressure to the one or more respective spraying elements ejecting cooling fluid onto the magnet surfaces; Leijnen is directed to the stator per se and its sealed internal cooling circuit, and is silent regarding the rotor construction and rotor-side cooling.
However, Yao teaches the rotor comprising a first rotor disk being axially separated from the stator by an air gap and the first rotor disk comprises magnets, of which the magnet surfaces are located in an annular zone on the rotor disk side facing the air gap(first part 44 of rotor 16 spaced from stator 18 by first air gap 66; permanent magnet 50 having an annular disk shape attached to the axial surface of the rotor part facing the stator) (¶[0037]–[0039]; Fig. 2),
one or more spraying elements each comprising at least one exit hole, and one or more cooling channels adapted to guide a cooling fluid under pressure thereto, adapted to eject cooling fluid towards the annular magnet zone, such that during operation with rotating rotor, the magnets are cooled by cooling fluid sprayed directly on the respective magnet surfaces(branch coolant channels 108 having radial first portions 112 extending inwardly from coolant jacket 104 and axial second portions 114 opening at the air-gap-facing surface of the stator; the channels are alternatively denominated orifices; pump 88 pressurizes the coolant; the ejected coolant flows through the air gap and cools the permanent magnet directly) (¶[0041]; ¶[0047]–[0048]; ¶[0050]; ¶[0032]; Fig. 2).
One would be motivated to provide, in the machine of Leijnen, cooling channels extending through the stator and terminating in exit holes at the first cover so as to eject the pressurized cooling fluid into the air gap toward the rotor magnets, as taught by Yao, in order to prevent the performance of the magnets from being significantly reduced or the magnets being permanently demagnetized at high temperature (Yao, ¶[0031]) and to cool both the permanent magnet and the coil windings, Yao teaching that coolant may be supplied to the air gap between the stator and the rotor in an axial flux machine without yielding high drag torque (Yao, ¶[0032]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Leijnen and Yao, as the combination is no more than the predictable use of prior art elements according to their established functions. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007).
Regarding claim 2/1, Leijnen in view of Yao teaches the axial flux machine of claim 1.
Yao further teaches the one or more spraying elements are provided as one or more respective holes(branch coolant channels, or orifices, the second portions 114 whereof open at the air-gap-facing surface, in the combination provided through the first cover of Leijnen)
thereby being adapted to eject the cooling fluid as a jet pointing at the magnet zone(pump-pressurized coolant discharged axially from the openings toward the annular disk magnet 50 across the air gap) (¶[0041]; ¶[0048]; ¶[0050]; Fig. 2).
One would be motivated to provide the spraying elements as holes ejecting a jet at the magnet zone, as taught by Yao, in order to spray the pressurized cooling fluid directly against the permanent magnets and thereby prevent their demagnetization at high temperature (Yao, ¶[0031]–[0032]).
Regarding claim 3/1, Leijnen in view of Yao teaches the axial flux machine of claim 1.
Yao further teaches the one or more cooling channels branch off from a cooling circuit(branch coolant channels 108, 110 extending from the annular coolant jacket 104) (¶[0047]–[0049]; Fig. 2).
In the combination, the channels branch off from the cooling circuit of Leijnen for cooling the stator elements, the outer cooling channel of Leijnen being the annular supply channel of the stator cooling circuit (Leijnen, ¶[0010]; ¶[0030]; ¶[0032]).
One would be motivated to branch the cooling channels off from the stator cooling circuit, in the manner of the jacket-fed branch channels of Yao, in order to supply the spraying elements from the single pump-driven coolant circuit of the machine (Yao, ¶[0043]; ¶[0047]).
Regarding claim 4/1, Leijnen in view of Yao teaches the axial flux machine of claim 1.
Yao further teaches the cooling fluid is a cooling liquid, for example oil(the pump sends coolant, e.g., oil) (¶[0043]; ¶[0050]).
One would be motivated to employ oil as the cooling fluid, as taught by Yao, oil being the coolant Yao discloses for cooling both the permanent magnet and the coil windings (Yao, ¶[0032]; ¶[0043]).
Regarding claim 5/1, Leijnen in view of Yao teaches the axial flux machine of claim 1.
Leijnen further teaches the first cover has an outer circumference and an inner circumference(annular cover 401, having by its annular shape an outer and an inner circumference) (¶[0039]; Fig. 4).
Yao further teaches any of the one or more spraying elements is located at a radial position closer to the inner circumference than to the outer circumference(the axial second portions 114, 118 open into the air gaps at the radially inner region of the stator, radially inboard of the magnets, the coolant thereafter sweeping radially outward through the air gaps) (Fig. 2; ¶[0048]–[0052]).
One would be motivated to locate the spraying elements radially closer to the inner circumference, as taught by Yao, so that the ejected cooling fluid sweeps radially outward across the magnet surfaces through the air gap toward the coolant return channels disposed radially outward of the air gaps (Yao, ¶[0039]; ¶[0051]–[0052]).
Regarding claim 6/1, Leijnen in view of Yao teaches the axial flux machine of claim 1.
Leijnen further teaches any of the one or more cooling channels is in fluid communication with a fluid inlet located at the outer circumference of the stator(first port coupled to the outer cooling channel of the outer structure, through which the cooling fluid is supplied to the stator) (¶[0009]; ¶[0030]; ¶[0060], Fig. 8, supplying port 800)
such that, during operation, cooling fluid is guided from the outer towards the inner circumference of the stator, before being ejected via the one or more spraying elements(the cooling fluid enters the stator in the outer cooling channel and the guiding walls guide the cooling fluid towards the inner cooling channel; likewise in Yao the coolant flows radially inward from the jacket 104 before being ejected into the air gaps) (Leijnen, ¶[0032]; Yao, ¶[0050], Fig. 2).
One would be motivated to eject the cooling fluid after it is guided from the outer towards the inner circumference, as taught by Yao, in order to supply the spraying elements from the radially outer coolant supply while delivering the fluid to the air gap (Yao, ¶[0047]; ¶[0050]).
Regarding claim 7/1, Leijnen in view of Yao teaches the axial flux machine of claim 1.
Yao further teaches any of the one or more cooling channels comprises a radial portion adapted to guide cooling fluid from the outer towards the inner circumference of the stator(first portion 112 extending radially inward from the coolant jacket 104)
and an end portion provided as a channel through the material of the first cover and ending in the spraying element, the end portion being in fluid communication with the radial portion(second portion 114 extending axially from the first portion 112 through the stator to the first air gap; in the combination the axial channel runs through the material of the first cover of Leijnen and ends in the exit hole) (¶[0047]–[0048]; ¶[0050]; Fig. 2).
One would be motivated to provide the cooling channels with a radial portion and an end portion, as taught by Yao, in order to conduct the pressurized cooling fluid from the radially outer supply through the stator to the air gap (Yao, ¶[0047]–[0048]).
Regarding claim 8/7, Leijnen in view of Yao teaches the axial flux machine of claim 7.
Yao further teaches the radial portion is provided as a channel running through the material of the first cover(the branch coolant channels extend radially inward from the annular coolant jacket through the housing and the stator, the first portions 112 thereby running through solid stator material; in the combination the radial portion runs through the material of the first cover of Leijnen) (¶[0013]; ¶[0048]; Fig. 2).
One would be motivated to run the radial portion through the material of the first cover, as taught by Yao, whose branch coolant channels extend through the housing and the stator, thereby conveying the cooling fluid to the air gap (Yao, ¶[0013]).
Regarding claim 9/7, Leijnen in view of Yao teaches the axial flux machine of claim 7.
Leijnen further teaches the radial portion is a fluid passage defined by the internal side of the first cover and the upper side of a coil, such that during operation, the cooling fluid is guided between the upper side of the coil and the internal side of the first cover when flowing from the outer towards the inner circumference of the stator(spacings between adjacently wound turns shape radial channels 510–512 as fluid passages between the outer and inner cooling channels, the radial channels lying in the upper side of the coil and sealed from above by the annular cover 401 positioned directly over the turns; the cooling fluid flows through the radial channels 510–512 into the inner cooling channel) (¶[0024]–[0025]; ¶[0054]–[0055]; ¶[0057]; ¶[0040]; ¶[0065]; Figs. 9A, 9B).
Yao teaches an end portion branching off from a radial coolant conduit (second portion 114 branching from first portion 112) (¶[0048]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the end portion branches off from the fluid passage by branching the end portion of the combination from the radial channels of Leijnen, as the simple substitution of one known radial coolant conduit for another as the source of the branch, yielding the predictable result of delivering the pressurized cooling fluid to the air gap for direct magnet cooling (Yao, ¶[0032]). See KSR, 550 U.S. at 417.
Regarding claim 11/7, Leijnen in view of Yao teaches the axial flux machine of claim 7.
Leijnen further teaches the radial portion is one of the fluid passages between adjacent stator elements for cooling of the stator elements, such that during operation, the cooling fluid is guided between two adjacent stator elements when flowing from the outer towards the inner circumference of the stator(fluid passage 610 between the coils of the stator elements, guided by guiding wall 104 between the coils; the cooling fluid flows through the intermediate structure between the outer and the inner cooling channel to cool the stator elements 105; alternating fluid passages 710–713) (¶[0013]–[0014]; ¶[0051]; ¶[0053]; ¶[0056]; ¶[0064]; Figs. 6–7).
Yao teaches an end portion branching off from a radial coolant conduit (second portion 114 branching from first portion 112) (¶[0048]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the end portion branches off from the fluid passage by branching the end portion of the combination from the fluid passages of Leijnen, as the simple substitution of one known radial coolant conduit for another as the source of the branch, yielding the predictable result of delivering the pressurized cooling fluid to the air gap for direct magnet cooling (Yao, ¶[0032]). See KSR, 550 U.S. at 417.
Regarding claim 12/1, Leijnen in view of Yao teaches the axial flux machine of claim 1.
Leijnen further teaches the cores of the stator elements extend through the first cover, such that surfaces of the respective cores are in contact with the air gap(the end faces of the stator elements 105 are exposed through the annular cover 401, compare Fig. 3, showing the uncovered stator, with Fig. 4, showing the stator covered by the annular cover 401 with the end faces of the elements 105 visible therethrough; the exposed end faces confront the air gap when the stator is mounted in the axial flux machine) (Figs. 2–4; ¶[0065]; ¶[0047]).
In the combination, during operation of the machine, at least part of the cooling fluid ejected by the one or more spraying elements splashes against the core surfaces, thereby cooling the cores, the cooling fluid being ejected into the air gap bounded by the exposed core surfaces (Yao, ¶[0032]; ¶[0050]; Fig. 2).
One would be motivated to eject the cooling fluid into the air gap bounded by the exposed core surfaces, as taught by Yao, in order to cool both the permanent magnet and the coil windings with the coolant flowing through the air gap (Yao, ¶[0032]).
Regarding claim 13/1, Leijnen in view of Yao teaches the axial flux machine of claim 1.
Yao further teaches the rotor comprises a second rotor disk being axially separated from the stator by a second air gap(second part 46 of the rotor 16 spaced from the stator 18 by second air gap 68),
the second rotor disk comprises magnets, of which the magnet surfaces are located in an annular zone on the disk side facing the second air gap(annular disk-shaped permanent magnet 50 attached to the axial surface of the second rotor part facing the stator),
and a second set of one or more spraying elements with a second set of one or more cooling channels adapted to guide a cooling fluid under pressure to the one or more respective spraying elements of the second set, adapted to eject cooling fluid towards the annular magnet zone of the second rotor disk(second pair of branch coolant channels 110, having first portions 116 and second portions 118 opening into the second air gap 68 and ejecting the pump-pressurized coolant against the magnet of the second rotor part) (¶[0037]–[0039]; ¶[0049]–[0050]; Fig. 2).
Leijnen further teaches the stator housing comprises a second cover facing the second air gap(a sealing cover 401 is positioned at both sides of the stator) (¶[0065]; Figs. 4, 9A).
One would be motivated to provide the second set of spraying elements and cooling channels at the second cover, as taught by Yao, in order to supply cooling fluid to both air gaps and thereby cool the permanent magnets of both rotor parts and prevent their demagnetization at high temperature (Yao, ¶[0031]; ¶[0049]).
Regarding claim 14/13, Leijnen in view of Yao teaches the axial flux machine of claim 13.
Yao further teaches any of the one or more cooling channels comprises a radial portion adapted to guide cooling fluid from the outer towards the inner circumference of the stator, and an end portion provided as a channel through the material of the first cover and ending in the spraying element, the end portion being in fluid communication with the radial portion(first portion 112 and second portion 114 of branch coolant channel 108; in the combination the second portion runs through the material of the first cover of Leijnen) (¶[0048]; Fig. 2),
and any of the one or more cooling channels of the second set comprises a final portion provided as a channel through the material of the second cover and ending in the spraying element of the second set(second portion 118 of branch coolant channel 110, extending axially to the second air gap; in the combination running through the material of the second cover of Leijnen) (¶[0049]; Fig. 2).
Yao further teaches the final portion is in fluid communication with the radial portion(the second portion 118 is in fluid communication with the first portion 112 at least via the first portion 116 and the common coolant jacket 104, to which both pairs of branch coolant channels are connected and from which both are supplied) (¶[0047]; ¶[0050]; Fig. 2).
The term “in fluid communication” is given its broadest reasonable interpretation encompassing indirect fluid communication, consistent with claim 15, which specifies an intermediate portion establishing the fluid communication recited in claim 14. One would be motivated to supply the final portion and the radial portion from a common coolant supply, as taught by Yao, in order to feed both sets of cooling channels from the single pump-pressurized circuit (Yao, ¶[0047]; ¶[0050]).
Allowable Subject Matter
Claims 10 and 15 would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims and amended to overcome the rejections under 35 U.S.C. 112(b) set forth in this Office action.
The following is a statement of reasons for the indication of allowable subject matter:
The closest prior art of record, Leijnen (EP 3 764 526 A1), Yao (US 2021/0288554 A1), Woolmer (US 2017/0012480), and Woolmer (US 2015/0364956), does not teach or fairly suggest, in combination with the remaining limitations of the respective claims, “a plate, the plate positioned between the internal side of the first cover and the upper side of a coil, such that during operation, the cooling fluid is guided between the plate and the internal side of the first cover” as recited in claim 10, nor “an intermediate portion provided as a channel running through the material of the wall, the intermediate portion being in fluid communication with both the radial portion and the final portion” together with the wall “axially extending between the first and second cover” as recited in claim 15.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant’s disclosure:
Woolmer (US 2017/0012480) teaches an axial flux machine having a stator housing enclosing a set of coils wound on respective stator bars, with a coolant flowing through the stator housing around and between the coils.
Woolmer (US 2015/0364956) teaches an axial flux motor stator having cooling channels defined between heat exchange surfaces of pole shoes and the coils.
McCaw (US 2018/0145574) teaches rotor cooling of an axial flux machine by impeller blades located on the rotor.
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. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pairdirect. uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free).
/MOHAMMED AHMED QURESHI/Examiner, Art Unit 2834
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