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 .
Claim Objections
Claims 1 and 9 are objected to because of the following informalities:
Claim 1, ¶ 3, ll. 8, “said air gap surface” should be “said second air gap surface.”
Claim 9 ll. 1-2, “said a radial bearing” should be “a radial bearing.”
Appropriate correction is required.
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.
Claim 8 is 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 8 recites “said magnetic barrier structure is made of materials with a different magnetic permeability coefficient, including ferrite, to control magnetic flux.” The claim does not recite what structure or material the magnetic barrier structure is compared to. For examination purposes, the claim will be interpreted in the broadest reasonable interpretation, where the magnetic barrier structure is a ferrite material.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 are rejected under 35 U.S.C. 103 as being unpatentable over McMullen et al. (US 2002/0175578 A1) in view of Ono et al. (US 2020/0350804 A1) and Wang et al. (CN 106763186 A).
Regarding claim 1, McMullen discloses an axial active magnetic bearing (110), symmetric to a rotation axis (FIG. 6), said axial active magnetic bearing (110) comprising:
a rotating shaft (111, 112), comprising a main shaft (112) and a thrust plate (111), said main shaft (112) coaxial with said rotation axis, and said thrust plate (111) concentrically arranged on said main shaft (112);
a magnetic yoke (113, 114), comprising a first side (113) and a second side (114) opposite to each other, said first side (113) and said second side (114) respectively provided on two axial sides of said thrust plate (111) and not contacting said thrust plate (111), a corresponding end of said first side (113) and said second side (114) having a chamber (housing coil 115; see annotation below), said chamber positioned on a radial outside of said thrust plate (111), said first side (113) having a first air gap surface (121) adjacent to said chamber, said second side (114) having a second air gap (120) adjacent to said chamber, a first air gap (see annotation below) formed between said first air gap surface (121) and said thrust plate (111), a second air gap (see annotation below) formed between said air gap surface (120) and said thrust plate (111); and
a permanent magnet (117), provided on a surface of said magnetic yoke (113, 114) facing said thrust plate (111) relative to said main shaft (112), said permanent magnet (117) not contacting said thrust plate (111), a third air gap (see annotation below) formed between said thrust plate (111) and said permanent magnet (117), and a permanent magnet magnetic flux (119) formed between said permanent magnet (117) and said magnetic yoke (113, 114);
a magnetic barrier structure (where flux 119 flow; see annotation below), provided on said first side (113) and positioned between said permanent magnet (117) and said first air gap surface (121), said first side (113) having a first distance of cross-section area (121) parallel to said rotation axis, said magnetic barrier structure having a second distance of cross-section area parallel to said rotation axis, said second distance of cross-section area smaller than said first distance of cross-section area (FIG. 6; the magnetic barrier is closer to the shaft than the first air gap surface), said magnetic barrier structure positioned in a path of said permanent magnet magnetic flux (119), and permanent magnet magnetic flux (119) passed through said magnetic barrier structure, said first air gap and said third air gap (FIG. 6); and
an electromagnetic coil (115), provided in said chamber and not contacting said thrust plate (111), a control magnetic flux (122) formed between said thrust plate (111) and said magnetic yoke (113, 114) after control current flows in said electromagnet coil (115; ¶ [0032]), and said control magnetic flux (122) passed through said first air gap and said second air gap.
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McMullen does not disclose the axial active magnetic bearing fixed to a structural object:
the error in a projected area size of said first air gap and said second air gap along the direction of said rotation axis less than 5%.
Ono discloses the axial active magnetic bearing (16) fixed to a structural object (11, 40).
It would have been obvious to one of ordinary skill in the art before the effective filing of the claimed invention to have modified McMullen in view of Ono to disclose the axial active magnetic bearing fixed to a structural object, as magnetic bearings are commonly used in electrical machines for supporting a motor shaft in a non-contact manner for frictionless rotation.
Wang discloses the error in a projected area size of said first air gap (7) and said second air gap (7) along the direction of said rotation axis less than 5% (all airgaps are set to be equal at 0.5 mm).
It would have been obvious to one of ordinary skill in the art before the effective filing of the claimed invention to have modified McMullen in view of Wang to disclose the error in a projected area size of said first air gap and said second air gap along the direction of said rotation axis less than 5%, as it is desired for the magnetic bearing to be axially symmetrical for the advantages of compact structure and small size.
Regarding claim 2/1, McMullen in view of Ono and Wang was discussed above in claim 1. McMullen further discloses a projection range of said first air gap and a projection range of said second air gap along the direction of said rotation axis are completely or partially overlapped (FIG. 6; the first air gap and the second air gap are completely overlapped in the axial direction).
Regarding claim 3/1, McMullen in view of Ono and Wang was discussed above in claim 1. Ono further discloses said main shaft (12) is a magnetic body (¶ [0048]), and said main shaft (12) and said magnetic yoke (16a, 16b) are separated a first distance, allowing said main shaft (12) not to contact said magnetic yoke (16a, 16b; FIG. 1).
Regarding claim 4/1, McMullen in view of Ono and Wang was discussed above in claim 1. Ono further discloses said structural object (11, 40) is a magnetic body (motors 20 comprise magnetic materials), and said structural object (11, 40) and said thrust plate (12a) are separated a second distance, allowing said structural object (11, 40) not to contact said thrust plate (12a).
Regarding claim 5/1, McMullen in view of Ono and Wang was discussed above in claim 1. Ono further discloses both said structural object (11, 40) and said main shaft (12) are magnetic bodies (motors 20 comprise magnetic materials; ¶ [0048]), and said structural object (11, 40) and said main shaft (12) are separated a third distance, allowing said structural object (11, 40) not to contact said main shaft (12; the casing 11 of the structural object is spaced from the main shaft).
Regarding claim 6/1, McMullen in view of Ono and Wang was discussed above in claim 1. McMullen further discloses a magnetic plate (244) with magnetic permeability (¶ [0037] magnet cap pieces) is provided on a surface of said permanent magnet (237) facing said thrust plate (231), allowing a magnetic field of said third air gap to be uniformly distributed (FIG. 11).
Regarding claim 7/1, McMullen in view of Ono and Wang was discussed above in claim 1. McMullen further discloses said magnetic barrier structure, said second air gap and said third air gap are all positioned in paths of a permanent magnet magnetic leakage flux generated from said permanent magnet magnetic flux (119) and a control magnetic leakage flux generated from said control magnetic flux (122; flux 119 and 122 would create a leakage flux around the yoke 113 and 114 between the gaps in the magnetic bodies).
Regarding claim 8/1, McMullen in view of Ono and Wang was discussed above in claim 1. McMullen further discloses said magnetic barrier structure is made of materials with a different magnetic permeability coefficient, including ferrite, to control magnetic flux (¶ [0014] upper and lower yoke made of ferrous member).
Regarding claim 9/1, McMullen in view of Ono and Wang was discussed above in claim 1. Ono further discloses a radial bearing (15) is provided between said rotating shaft (12) and said structural object (11, 40), allowing said rotating shaft (12) to maintain a radial relative position with said radial bearing (15) and said structural object (11, 40).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MINKI CHANG whose telephone number is (571)270-0521. The examiner can normally be reached 9:00 AM - 5:00 PM.
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/MINKI CHANG/Examiner, Art Unit 2834
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