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 .
Specification
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
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) 1-8 and 10 is/are rejected under 35 U.S.C 103 as being unpatentable over IONEL(US20080224558A1) in view of SILANDER(US8084910B2).
Regarding claim 1, Ionel teaches a rotor(16) having a magnet-embedded structure(Para[0049-0050]), the rotor comprising: a rotor core(40); and a magnet(45) held in the rotor core(40), wherein the magnet(45) is accommodated in an accommodation hole(55,140,345) provided in the rotor core(40), and wherein the magnet has a first surface and a second surface which extend in a direction intersecting with a magnetization direction, which is a direction of magnetic field lines inside the magnet, and opposes each other(The permanent magnets are magnetized to form N and S poles and are arranged within the rotor such that magnetic field lines extend through the rotor and air gap, inherently defining opposing magnet surfaces along the magnetization direction (see paragraphs [0081]–[0082])).
Ionel is silent wherein at least one of the first surface and the second surface is provided with a concave portion, which is provided with a curved surface in a concaved shape at a middle portion between both ends in a longitudinal cross-section.
However, Silander teaches wherein at least one of the first surface and the second surface is provided with a concave portion(Permanent magnet 6 has concave surface 4), which is provided with a curved surface in a concaved shape at a middle portion between both ends in a longitudinal cross-section(Silander discloses that the air-gap distance at the middle of the pole is smaller than the air-gap distance at the pole edges (dimensions C and E), which necessarily results from a curved concave magnet surface whose maximum concavity is located at the middle portion between the longitudinal ends of the magnet (see paragraph [0017])).
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the embedded permanent magnet of Ionel to include the concave magnet surface taught by the secondary reference, because Silander teaches that concave magnet surface geometry improves air-gap flux distribution and reduces torque ripple. Applying this known magnet surface shaping technique to the embedded magnets of the primary reference would have been a predictable design modification yielding known benefits without altering the fundamental operation of the interior permanent magnet rotor.
Regarding claim 2/1, Ionel in view of Silander teaches the rotor according to claim 1.
Ionel further teaches wherein a permanent magnet (45) is accommodated in an accommodation hole (55, 140, 345) formed in a rotor core (40) such that inner surfaces of the accommodation hole face the magnet surfaces (see paragraphs [0056]–[0065]). Ionel therefore teaches a rotor core having an inner surface defining an accommodation hole and facing a surface of the magnet.
Ionel is silent as to the magnet having a magnet specific surface on which a concave portion is formed, and the rotor core having a core specific surface with a convex portion that is received in the concave portion on the magnet specific surface.
Silander teaches that a permanent magnet (6) includes a concave surface (4), and that the concave surface of the permanent magnet is arranged to mate with a convex surface (18) of a rotor body (16), such that the convex portion of the rotor body is received in the concave portion of the magnet (see paragraphs [0014]–[0017]). Silander therefore teaches a concave magnet specific surface and a corresponding convex core specific surface received in the concave portion of the magnet.
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the embedded permanent magnet and accommodation hole of Ionel to include the concave magnet surface and mating convex core surface taught by Silander, because such complementary concave-convex interface geometry is known to improve mechanical fit, retention, and magnetic flux distribution. Applying this known mating surface geometry to the embedded magnet structure of Ionel would have been a predictable design modification yielding known benefits without altering the fundamental operation of the interior permanent magnet rotor.
Regarding claim 3/2, Ionel in view of Silander teaches the rotor according to claim 2.
Silander teaches that a permanent magnet (6) having a concave surface (4) is arranged such that a distance at a middle portion of the magnet differs from a distance at portions where the concave portion is not provided(Fig. 3, as evidenced by the air-gap distance at the middle portion (C) being different from the air-gap distance at the pole edges (E) (see paragraph [0017]).
Regarding claim 4/3, Ionel in view of Silander teaches the rotor according to claim 3.
Silander teaches that a permanent magnet (6) having a concave surface (4) is arranged such that a distance at a middle portion of the magnet(C) is smaller than the distance at portions where the concave portion is not provided(E)(Fig. 3, see paragraph [0017]).
Regarding claim 5/2, Ionel in view of Silander teaches the rotor according to claim 2.
Silander teaches wherein one of the portion where the concave portion(part of 4) is provided on the magnet specific surface(part of 6) and the portion where the concave portion(part of 4) is not provided is in contact with the core specific surface(18)(Figs. 1-3, see paragraphs [0014-0017]).
Regarding claim 6/2, Ionel in view of Silander teaches the rotor according to claim 2.
Silander teaches wherein the portion where the concave portion(part of 4) is provided on the magnet specific surface(part of 6) is in contact with the core specific surface(18) among the portion where the concave portion(part of 4) is provided on the magnet specific surface and the portion where the concave portion is not provided(Figs. 1-3, see paragraphs [0014-0017]).
Regarding claim 7/2, Ionel in view of Silander teaches the rotor according to claim 2.
Silander teaches wherein a relationship between a curvature radius A of the concave portion(part of 4) on the magnet specific surface and a curvature radius B of the convex portion(part of 18) on the core specific surface is A<B(Figs. 1-3, air-gap in center is smaller than at edges, which means concave portion has a smaller curvature radius.).
Regarding claim 8/2, Ionel in view of Silander teaches the rotor according to claim 2.
Ionel in view of Silander does not explicitly teach wherein a relationship between a curvature radius A of the concave portion on the magnet specific surface and a curvature radius B of the convex portion on the core specific surface is A>B.
However, Silander further teaches that the shape of the concave portion of the permanent magnet and the convex portion of the rotor body may be selected and modified to achieve a desired air-gap flux distribution (see paragraphs [0003], [0006], and [0017]). The selection of curvature radii for mating concave and convex surfaces is a design parameter, and it would have been obvious to one of ordinary skill in the art to select a curvature radius A of the concave portion on the magnet specific surface that is greater than a curvature radius B of the convex portion on the core specific surface (A > B) as an alternative geometric configuration to achieve predictable magnetic and mechanical performance.
Regarding claim 10/2, Ionel in view of Silander teaches the rotor according to claim 2.
Ionel further teaches wherein the accommodation hole(55,140,345) of the rotor core(40) includes gaps(60) which are provided on outside of both ends of the magnet(45) in a longitudinal cross-section, and wherein the gaps(60) are provided with no positioning step which comes in contact with an end surface between the first surface and the second surface of the magnet(Fig. 1).
Claim(s) 9 is/are rejected under 35 U.S.C 103 as being unpatentable over IONEL(US2008224558A1) in view of SILANDER(US8084910B2) and further in view of RAHMAN(US20050275302A1).
Regarding claim 9/2, Ionel in view of Silander teaches the rotor according to claim 2.
Silander teaches wherein the wherein the magnet specific surface of the magnet(6) has a first flat portion on a side of the d-axis and a second flat portion on a side of the q-axis, among both sides with respect to the concave portion(part of 4)(Fig. 6, Magnet 6 made of multiple pieces forming a pole, where the surface includes flat lateral portions adjacent concave surface 4), and wherein the second flat portion is wider than the first flat portion in a width direction in which the concave portion and both flat portions are arranged(Fig. 3, asymmetric pole geometry in which edge regions differ from center from the center region in width which results in unequal flat surface widths adjacent the concave surface).
Ionel in view of Silander is silent wherein the magnet includes pieces arranged on both sides of a d-axis, which is a magnetic pole center in the rotor core, respectively, and is placed in an orientation in which one end side of the first surface and the second surface is placed on a side of the d-axis and the other end side is placed on a side of a q-axis in a view of a longitudinal cross-section.
However, Rahman teaches wherein the magnet includes pieces arranged on both sides of a d-axis, which is a magnetic pole center in the rotor core, respectively, and is placed in an orientation in which one end side of the first surface and the second surface is placed on a side of the d-axis and the other end side is placed on a side of a q-axis in a view of a longitudinal cross-section(Para[0002-0003]).
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the rotor of Ionel to incorporate the magnet surface geometry taught by Silander and the d-axis / q-axis-based magnet arrangement taught by Rahman, because all three references are directed to interior permanent-magnet synchronous machines and address complementary aspects of rotor design.
A person of ordinary skill in the art would have been motivated to apply the magnet surface shaping of Silander to the axis-based magnet arrangement of Rahman within the embedded-magnet rotor of Ionel in order to further optimize flux distribution between the d-axis and q-axis regions. Once asymmetric d-axis / q-axis magnet placement is adopted, selecting different widths for flat portions of the magnet surface on the d-axis side and q-axis side represents a predictable design choice for tailoring saliency and air-gap flux, and therefore would have been an obvious matter of routine optimization.
The proposed combination merely involves applying known magnet surface shaping techniques to known axis-based magnet arrangements in an interior permanent-magnet rotor, and yields predictable results without changing the fundamental principle of operation of the rotor.
Conclusion
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
/TULSIDAS C PATEL/Supervisory Patent Examiner, Art Unit 2834