FINAL 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 .
Response to Arguments
Applicant's arguments filed 23 December 2025 have been fully considered but they are not persuasive.
In response to Applicant’s argument that “[w]ith regard to Kech, which is relied on by the Examiner for teaching the annular flange as recited in claim 4, Applicant respectfully submits that Kech does not teach the claimed partition wall formed by the base of the centrifuge housing, and even if Tornblom was modified to include a split house in view of the teachings of Stark and Kech, such a split house would be coupled to middle frame 392/394 or motor housing 386 or rotor housing 4 of Tornblom in view of the teachings of Kech. There is no teaching that would have led one skilled in the art to seal the split house to the alleged partition wall 70’’ of Tornblom” (page 10, Remarks), the examiner respectfully disagrees. Törnblom teaches that bearing plate 70’ closes the lower open end of rotor housing 4’ and serves as the wall separating the separator region from the lower motor region. Additionally, Törnblom teaches that, in the electric motor of Fig. 35, separated oil passes downwardly through bottom bearing unit 90, is ejected into the interior of motor housing 384, enters the space within cylindrical wall 392, then passes through rotor 382 and may pass through the space between rotor 382 and stator 400 before exiting via port 402 (para. [0521]). Stark is relied upon for teaching the split case between the motor rotor and stator, and Kech is relied upon for teaching the annular flange and circumferential sealing arrangement to seal the split case to an adjacent structural boundary. One of ordinary skill in the art would have found it obvious to use the bearing plate 70’ as the boundary at which to provide the seal, since bearing plate 70’ already defines the boundary between the wet separator side and the motor side in Törnblom. Applying Kech’s annular flange and circumferential seal at the bearing plate 70’ would have been a predictable use of a known sealing technique to obtain the expected benefit of separating the fluid rotor side from the dry stator side in the split case. The rejection over Törnblom in view of Stark and Kech are therefore still deemed valid and are maintained.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Drawings
The drawings were received on 29 December 2022. These drawings are acceptable.
Specification
The specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant's cooperation is requested in correcting any errors of which applicant may become aware of in the specification.
The title of the invention is acceptable.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 2, 4, 8-11, 15-18, 20, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Törnblom et al. (U.S. Patent Application Pub. No. 2012/0174538, hereinafter Törnblom) in view of Stark et al. (U.S. Patent No. 3,475,631, hereinafter Stark), and further in view of Kech et al. (U.S. Patent No. 6,365,998, hereinafter Kech).
Regarding claim 1, Törnblom discloses a centrifugal separator (Fig. 34) for separating oil, the centrifugal separator comprising a centrifuge housing (rotor housing 4’, Fig. 13), a drive housing (motor housing 384, Fig. 35), a separating rotor (stack of separator discs 84’, Fig. 13), a shaft (rotary shaft 78’, Fig. 34), a first bearing (bottom bearing unit 90’, Fig. 34), a second bearing (top bearing unit 50’, Fig. 34) and a drive (electric motor 380, Fig. 35), wherein a drive chamber is formed in the drive housing (motor housing 384, Fig. 35), wherein a separating chamber is formed in the centrifuge housing (rotor housing 4’, Fig. 13), wherein a partition wall (bearing plate 70’, Fig. 34) is formed between the drive chamber and the separating chamber, the partition wall being formed by a base of the centrifuge housing (Törnblom discloses rotor housing 4’ having a lower open end that is closed by the bearing plate 70’ such that the bearing plate 70’ forms the wall separating the separation chamber from the lower chamber, para. [0364], Fig. 35; Thus, bearing plate 70’ reasonably reads on a partition wall formed by a base of the centrifuge housing, since the base does not need to be integral with the remainder of the centrifuge housing), wherein the partition wall comprises an opening, the first bearing (bottom bearing unit 90’, Fig. 34) being mounted in the opening of the partition wall formed by the base of the centrifuge housing (para. [0364]), wherein the shaft (rotary shaft 78’, Fig. 34) extends through the opening of the partition wall (bearing plate 70’, Fig. 34) into the separating chamber and into the drive chamber (see Fig. 34), wherein the separating rotor (stack of separator discs 84’, Fig. 13) is connected to the shaft (rotary shaft 78’, Fig. 34) for conjoint rotation and is arranged in the separating chamber (para. [0432]), wherein the drive (electric motor 380, Fig. 35) is arranged in the drive chamber (chamber defined by motor housing 384, Fig. 35) and drives the shaft, wherein the drive is in the form of an electric motor (electric motor 380, Fig. 35) which drives the shaft directly in such a way that the shaft forms a motor shaft (rotary shaft 78’’, Fig. 35) of the electric motor (“a supply of electricity is connected to the brushless electric motor so as to operate the rotor thereof and thereby rotate the rotary shaft, para. [0521]), a rotor (382, Fig. 35) of the electric motor, and a stator (400, Fig. 35) of the electric motor, but does not disclose wherein the electric motor comprises a split case, a hollow cylindrical middle portion of the split case is arranged between a rotor of the electric motor and a stator of the electric motor, and the split case comprises an annular flange extending radially and facing the partition wall and is thereby sealed with respect to the partition wall.
Stark discloses analogous art related to integrating an electric motor into a housing where process fluid is circulated, wherein the electric motor comprises a split case (cylindrical stator can 54, Fig. 1), wherein a hollow cylindrical middle portion of the split case is arranged between a rotor (rotor assembly 12, Fig. 1) of the electric motor and a stator (stator assembly 10, Fig. 1) of the electric motor. It would have been obvious for one having ordinary skill in the art before the effective filing date of the claimed invention to have provided the motor arrangement in the centrifugal separator of Törnblom with the split case as taught by Stark for the purpose of sealing off the stator windings from the rotor cavity (col. 2 lines 61-70, Stark).
The combination of Törnblom and Stark does not disclose the split case comprises an annular flange extending radially and facing the partition wall and is thereby sealed with respect to the partition wall.
Kech discloses analogous art related an electric motor, comprising a split case (motor can 6, Fig. 1), a hollow cylindrical middle portion (cylindrical portion 6a, Fig. 1) of the split case is arranged between a rotor (rotor 5 and permanent magnets 18, Fig. 1) of the electric motor and a stator (coil or winding carrier 8, stator winding 17, and stator sheet stack 19, Fig. 1) of the electric motor, and the split case comprises an annular flange (flange 7, Fig. 1) extending radially and facing the partition wall (corresponds to cylindrical projection 1b, Fig. 1) and is thereby sealed with respect to the partition wall (sealed via O-ring 7a, Fig. 1). It would have been obvious for one having ordinary skill in the art before the effective filing date of the claimed invention to have provided the partition wall in the centrifugal separator of the combination of Törnblom and Stark with annular flange taught by Kech for the purpose of separating and protecting the stator from the oil/fluid in the rotor side of the motor (col. 1 lines 6-11, Kech).
Regarding claim 2, the combination of Törnblom, Stark, and Kech discloses wherein the shaft (rotary shaft 78’, Fig. 34, Törnblom) passes through the first bearing (bottom bearing unit 90’, Fig. 34, Törnblom).
Regarding claim 4, the combination of Törnblom, Stark, and Kech discloses wherein the split case comprises above the middle portion the annular flange (flange 7, Fig. 1, Kech) facing the partition wall (corresponds to cylindrical projection 1b, Fig. 1, Kech) with the interposition of a circumferential seal (O-ring 7a, Fig. 1, Kech).
Regarding claim 8, the combination of Törnblom, Stark, and Kech discloses wherein an air gap is formed, circumferentially, between the split case (cylindrical stator can 54, Fig. 1, Stark) and the rotor (rotor assembly 12, Fig. 1, Stark), wherein the air gap is in particular of such a size that the split case is spaced apart from the rotor in such a way that oil is able to flow unhindered in the direction of a longitudinal axis of the shaft at an inside wall of the split case ( “the impeller 18 circulates the liquid through the gap between the stator can 54 and the rotor assembly 12”, col. 4 lines 11-33, Stark).
Regarding claim 9, the combination of Törnblom, Stark, and Kech discloses wherein the first bearing (bottom bearing unit 90’, Fig. 34, Törnblom) is formed without a seal, in such a manner that oil is able to flow between the inner ring (see partial annotated Fig. 34 below, Törnblom) and an outer ring (see annotated partial Fig. 34 below, Törnblom) of the first bearing along rolling elements of the bearing (see arrows indicating flow path of oil through bearing 90’, Fig. 34, Törnblom).
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Regarding claim 10, the combination of Törnblom, Stark, and Kech discloses wherein the first bearing (bottom bearing unit 90’, Fig. 34, Törnblom) is in the form of a drain, and in that an upper side of the partition wall (bearing plate 70’, Fig. 34, Törnblom) is shaped in such a way that oil that collects on the upper side flows to the first bearing when the shaft is standing vertically in space (as shown by flow path arrows in Fig. 34, Törnblom).
Regarding claim 11, the combination of Törnblom, Stark, and Kech discloses wherein the centrifugal separator comprises an impeller (auxiliary impeller 18, Fig. 1, Stark), wherein the impeller is driven by the shaft (shaft 58, Fig. 1, Stark) and is connected to the shaft for conjoint rotation, wherein the impeller is arranged in the split case (cylindrical stator can 54, Fig. 1, Stark) adjacent to a rotor or the rotor of the electric motor (rotor assembly 12, Fig. 1, Stark) and above the rotor of the electric motor (see Fig. 1, Stark).
Regarding claim 15, the combination of Törnblom, Stark, and Kech discloses wherein the drive housing (motor housing 384, Fig. 35, Törnblom) comprising a connecting flange (see annotated Fig. 35 below) facing the centrifuge housing (rotor housing 4, Fig. 35, Törnblom) and is thereby connected to a counter-flange (see annotated Fig. 35 below) formed on the underside of the partition wall (bearing plate 70’’, Fig. 35, Törnblom) of the centrifuge housing, in such a manner that the drive chamber is closed on all sides.
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Regarding claim 16, the combination of Törnblom, Stark, and Kech discloses wherein the centrifugal separator is in the form of a blow-by gas centrifugal separator for an internal combustion engine (para. [0002], Törnblom).
Regarding claim 17, the combination of Törnblom, Stark, and Kech discloses wherein an inlet through which the blow-by gas flows into the separating chamber is formed by the second bearing (top bearing unit 50’, Fig. 34; three part-circular slots 66’ are provided in the top bearing unit 50’ so as to allow a flow of inlet fluid therepast, para. [0428], Törnblom).
Regarding claim 18, the combination of Törnblom, Stark, and Kech discloses wherein the centrifugal separator comprises a blow-by gas connection (piping for inlet fluid 68’, Fig. 34, Törnblom) is of such a size and is arranged on the centrifuge housing in such a way that the second bearing (top bearing unit 50’, Fig. 34, Törnblom) is thereby supplied with blow-by gas.
Regarding claim 20, the combination of Törnblom, Stark, and Kech discloses wherein the shaft (rotary shaft 78’, Fig. 35, Törnblom) extends through the opening of the drive housing (motor housing 384, Fig. 35, Törnblom), and the first bearing (bottom bearing unit 90’, Fig. 34, Törnblom) is arranged outside the drive chamber and is mounted on the drive housing.
Regarding claim 21, the combination of Törnblom, Stark, and Kech discloses wherein the partition wall (bearing plate 70’, Fig. 34, Törnblom) is perpendicular to the shaft (rotary shaft 78’, Fig. 34, Törnblom), the annular flange (flange 7, Fig. 1, Kech) of the split case (motor can 6, Fig. 1, Kech) is sealed with respect to the partition wall (corresponds to cylindrical projection 1b, Fig. 1, Kech) at a first location of the partition wall, the drive housing (casing 20, Fig. 1, Kech) comprises a connecting flange (see annotated Fig. 1 of Kech below) facing the centrifuge housing (corresponds to pump body 1c, Fig. 1, Kech) and is thereby connected to the partition wall of the centrifuge housing (corresponds to cylindrical projection 1b, Fig. 1, Kech) at a second location of the partitional wall (see annotated Fig. 1, Kech), and the second location is radially distanced from the first location by the partition wall.
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Claims 5 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Törnblom in view of Stark, and further in view of Kech, as applied to claim 1 above, and further in view of Mikkelsen et al. (U.S. Patent Application Pub. No. 9,225,221, hereinafter Mikkelsen).
Regarding claim 5, the combination of Törnblom, Stark, and Kech does not disclose wherein the split case forms a connecting piece beneath the middle portion and is thereby held in an opening of the drive housing with the interposition of a circumferential seal.
Mikkelsen discloses analogous art related to a wet-running electric motor including a stator housing and a can, wherein the split case (can 6, Fig. 1) forms a connecting piece (circular-cylindrical sealing flange 418, Fig. 1) beneath the middle portion and is thereby held in an opening of the drive housing (stator housing 4, Fig. 1) with the interposition of a circumferential seal (sealing ring 416, Fig. 1). It would have been obvious for one having ordinary skill in the art before the effective filing date of the claimed invention to have provided the centrifugal separator of the combination of Törnblom, Stark, and Kech with the connecting piece and circumferential seal as taught by Mikkelsen for the purpose of achieving fluid-tightness of the connection of the drive housing and the pump housing (col. 7 lines 43-67, Mikkelsen).
Regarding claim 6, the combination of Törnblom, Stark, Kech, and Mikkelsen discloses wherein the shaft (rotary shaft 78’, Fig. 35, Törnblom) extends through the opening of the drive housing (motor housing 384, Fig. 35, Törnblom), and the first bearing (bottom bearing unit 90’, Fig. 34, Törnblom) is arranged outside the drive chamber and is mounted on the drive housing.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Törnblom in view of Stark, and further in view of Kech, as applied to claim 1 above, and further in view of Tetzlaff et al. (U.S. Patent No. 8,358,043, hereinafter Tetzlaff).
Regarding claim 13, the combination of Törnblom, Stark, and Kech does not explicitly teach wherein a stator of the electric motor either lies directly against an inner peripheral surface of the drive housing or lies indirectly against an inner peripheral surface of the drive housing with the interposition of a thermal conductor.
Tetzlaff discloses analogous art related to a submersible electric motor, wherein a stator of the electric motor lies indirectly against an inner peripheral surface of the drive housing with the interposition of a thermal conductor (Abstract). It would have been obvious for one having ordinary skill in the art before the effective filing date of the claimed invention to have provided the centrifugal separator of the combination of Törnblom, Stark, and Kech with the thermal conductor taught by Tetzlaff for the purpose of improving heat transfer from the motor (Abstract, Tetzlaff).
Claims 14 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Törnblom in view of Stark, and further in view of Kech, as applied to claim 1 above, and further in view of Lauer et al. (U.S. Patent No. 12,046,957, hereinafter Lauer).
Regarding claims 14 and 19, the combination of Törnblom, Stark, and Kech does not disclose wherein electronic components of an electronic unit of the electric motor are connected in a heat-conducting manner to an inner side of a base of the drive housing by way of an electrically insulating heat conducting medium, wherein the electronic components are arranged on a circuit board; wherein the electrically insulating heat-conducting medium comprises a heat-conducting paste.
Lauer discloses analogous art related to electric motors, wherein electronic components (“electronic components”, col. 4 line 47-48) of an electronic unit (“control board”, col. 4 line 48) of the electric motor (2, Fig. 2) are connected in a heat-conducting manner to an inner side of a base of the drive housing (electronics housing 12, Fig. 3) by way of an electrically insulating heat conducting medium (“heat-conducting paste”, col. 4 line 59), wherein the electronic components are arranged on a circuit board (“control board”, col. 4 line 48); wherein the electrically insulating heat-conducting medium comprises a heat-conducting paste (“heat-conducting paste”, col. 4 line 59). It would have been obvious for one having ordinary skill in the art before the effective filing date of the claimed invention to have provided the centrifugal separator of the combination of Törnblom, Stark, and Kech with the electrically insulating heat-conducting medium connection as taught by Lauer for the purpose of better discharge of the waste heat into the heat capacity (col. 4 lines 45-64, Lauer).
Allowable Subject Matter
Claim 12 is 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, since the prior art does not teach or suggest wherein a pressure differential is generated by the rotating impeller that lowers a pressure in the split case between the opening of the partition wall and the impeller, and increases a pressure towards the opening of the drive housing.
Conclusion
THIS ACTION IS MADE FINAL. 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 SHUYI S LIU whose telephone number is (571)272-0496. The examiner can normally be reached MON - FRI 9:30AM - 2:30PM EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Claire Wang can be reached at 571-270-1051. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Shuyi S. Liu/Examiner, Art Unit 1774
/CLAIRE X WANG/Supervisory Patent Examiner, Art Unit 1774
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