111111
`
`1111111111111111111111111111111111111111111111111111111111111111111111111111
`US 20040108779Al
`
`(19) United States
`(12) Patent Application Publication
`Boettger et al.
`
`(10) Pub. No.: US 2004/0108779 A1
`Jun. 10, 2004
`(43) Pub. Date:
`
`(54) ELECTRIC MOTOR FOR A PUMP DRIVE
`
`Publication Classification
`
`(76)
`
`Inventors: Axel Boettger, Dresden (DE); Ullrich
`Kreiensen, Deisslingen (DE); Helmut
`Hans, Sankt Georgen (DE); Manfred
`Rauer, Sankt Georgen (DE)
`
`Correspondence Address:
`DUANE MORRIS LLP
`Suite 700
`1667 K Street, N.W.
`Washington, DC 20006 (US)
`
`(21) Appl. No.:
`
`10/687,834
`
`(22) Filed:
`
`Oct. 20, 2003
`
`(30)
`
`Foreign Application Priority Data
`
`Nov. 22, 2002
`
`(DE) ..................................... 102 54 670.3
`
`(51)
`
`Int. Cl? ............................ H02K l/04; F04B 17/00;
`F04B 35/04
`
`(52) U.S. Cl. .......................... 310/89; 310/43; 417/423.1;
`417/423.14
`
`(57)
`
`ABSTRACT
`
`Electrical motor for a pump drive, with a stator and a rotor
`for driving a pump impeller, the stator being embedded in a
`plastic body and the plastic body forming a chamber
`together with the stator in which the rotor is received, the
`chamber being closed at one shaft end of the rotor and the
`rotor being connected at the opposite (second) shaft end to
`the pump impeller.
`
`PETITIONERS' EXHIBIT 1128
`
`PAGE 1 OF 11
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`Patent Application Publication
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`Jun. 10, 2004 Sheet 1 of 5
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`US 2004/0108779 A1
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`Patent Application Publication
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`Jun. 10, 2004 Sheet 2 of 5
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`US 2004/0108779 A1
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`PAGE 3 OF 11
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`Patent Application Publication
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`Jun. 10, 2004 Sheet 3 of 5
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`US 2004/0108779 A1
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`Patent Application Publication
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`Jun. 10, 2004 Sheet 4 of 5
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`US 2004/0108779 A1
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`l'atent Application Publication Jun. 10,21104 Sheet 5 of 5
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`US 2004/0108779 Al
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`US 2004/0108779 Al
`
`Jun. 10,2004
`
`1
`
`ELECTRIC MOTOR FOR A PUMP DRIVE
`
`FIELD OF THE INVENTION
`
`[0001] The invention relates to an electric motor for a
`pump drive with a stator and a rotor for driving a pump
`impeller.
`
`BACKGROUND OF THE INVENTION
`
`It is well known to design electric motors for pump
`[0002]
`drives as so-called canned motors. A canned motor is a
`wet-rotor motor in which the rotor is surrounded by a metal
`sleeve-closed on one side and surrounded by the pumping
`medium. The cup shaped metal sleeve protects the stator,
`phase windings and motor electronics which may be con(cid:173)
`tained in the motor housing from the pumping medium. The
`cup shaped sleeve is positioned in the air gap between the
`rotor and stator. The motor shaft protrudes from the open end
`of the cup shaped sleeve and is fitted to a pump impeller.
`Examples of canned motors are described in DE 38 18 532
`Al, DE 44 38 132 Al, DE199 07 555 Al, DE41 29 590 Al,
`EPO 963 029 A2.
`
`[0003] Electric motors for driving feed pumps are known
`in the prior art in which the motors, for example, are
`completely separated from the pumping medium by a sealed
`bearing and a shaft seal. In this case the motor is arranged
`in an enclosed and sealed housing from which the shaft
`protrudes and is fitted to the pump impeller. In order to seal
`the shaft a roller bearing in combination with a rotary shaft
`seal for example can be used, serving as a seal to separate
`the motor from the pumping medium. Such motors have the
`disadvantage that the seals generate additional frictional loss
`and are subject to malfunction. The seal is frequently one of
`the major weak points of the pump drive, with pumping
`medium penetrating the motor if the seal is damaged,
`eventually leading to motor destruction.
`
`[0004] One object of the invention is to provide an electric
`motor for a pump which is designed as a wet-rotor motor.
`Wet-rotor motors, like canned motors, can be designed
`without the shaft seal system which is susceptible to mal(cid:173)
`function. Here the pumping medium circulates not only in
`the pump, but also in one part of the motor which part then,
`must be sealed in relation to its surroundings. The motor
`according to the invention is intended to ensure a reliable
`separation of the part of the motor chamber in which the
`pumping medium circulates from other parts of the motor,
`particularly from the stator and the electronics.
`
`[0005] More generally, it is also an object of the invention
`to provide an electric motor to drive a pump which is small,
`can be manufactured inexpensively and saves energy when
`operated. A brushless direct current (DC) motor should
`preferably be utilized, although the invention is not limited
`to this kind of motors.
`
`SUMMARY OF THE INVENTION
`
`[0006] This function is achieved by an electric motor
`including the features of claim 1.
`
`[0007] Advantageous embodiments of the invention are
`specified in the dependent claims.
`
`[0008] According to the invention, the stator is enclosed in
`a plastic body in order to separate it from and protect it
`
`against the pumping medium. Preferably the stator core and
`phase windings are completely enclosed by the plastic body,
`so that only the connection wires of the phase windings
`protrude from the plastic body itself. The plastic body is
`preferably manufactured by injection molding. The inven(cid:173)
`tion thus forms an enclosed, electromagnetic system embed(cid:173)
`ded in the plastic body, the plastic body preferably is
`designed so that a chamber is provided in which the rotor is
`placed which chamber is closed on one of the end faces of
`the rotor. On the other end face the rotor is mounted to the
`pump drive. The connection wires of the phase windings
`preferably should protrude from the plastic body at the
`opposite side of the closed end of the chamber in which the
`rotor is placed. This ensures that the chamber in which the
`rotor is placed is, in fact, completely closed and the pumping
`medium cannot creep through any possible gaps or cracks.
`
`[0009] The plastic body preferably should be designed
`such that further motor components (e.g. two bearing seats
`for supporting the rotor shaft) can be incorporated.
`
`[0010] Furthermore, the plastic body can also be designed
`so that means for fitting the motor can directly be molded
`onto the plastic body (e.g. a motor flange or other fitting
`means).
`
`[0011] A preferred embodiment of the invention has the
`stator integrated in a plastic body by injection molding. This
`involves production of the chamber closed on one side as a
`single component in one molding process. The function of
`the plastic body is to seal the drive system of the feed pump
`against the pumping medium to the outside and to protect the
`feed pump against environmental influences. Additionally,
`the plastic body provides means for precise positioning and
`fixing of the connection wires of the phase windings which
`protrude from the plastic body.
`
`[0012] The rotor with motor shaft and the pre-assembled
`bearings can be pushed into the chamber formed in the
`plastic body from its open end face, whereby the axial
`positioning and fixing of the motor shaft and the rotor is
`done by a positive locking with a pump housing to which the
`plastic body can be affixed.
`
`In another embodiment of the invention, the plastic
`[0013]
`body provides a chamber open on both sides in which the
`stator is located. One of the end faces of the chamber is
`closed by a cap produced from the same material (although
`another material may be used).
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0014] The invention is explained in greater detail below
`based on a preferred embodiment and with reference to the
`drawings, wherein:
`
`[0015] FIG. 1 shows a cross-sectional view of a first
`embodiment of the electric motor according to the invention;
`
`[0016] FIG. 2 shows a cross-sectional view of a second
`embodiment of the electric motor according to the invention;
`
`[0017] FIG. 3 shows an dismantled perspective view of
`the electric motor according to the invention in accordance
`with the first embodiment;
`
`[0018] FIGS. 4A and 4B show a side view and a per(cid:173)
`spective view of the plastic body used in the electric motor
`according to the invention;
`
`PAGE 7 OF 11
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`US 2004/0108779 Al
`
`Jun. 10,2004
`
`2
`
`[0019] FIGS. SA and 5B show a dismantled view and a
`perspective view of the rotor used in the electric motor
`according to the invention.
`
`DETAILED DESCRIPTION OF PREFERRED
`EMBODIMENT
`
`[0020] FIG. 1 illustrates a cross-sectional view of an
`electric motor according to a first preferred embodiment of
`the invention. The electric motor illustrated in FIG. 1 is a
`brushless DC motor, although the invention can generally be
`used with any electric motor being designed as canned or
`wet-rotor motors. A pump house is generally designated as
`10 in FIG. 1. The pump housing 10 holds a pump impeller
`(not illustrated) and has an inlet and outlet for the pumping
`medium. No further details of the pump itself are described
`here, as feed pumps are commonly known from the prior art.
`The electric motor according to the invention is generally
`designated as 20. It comprises a rotor 22 with a coil flux
`guide (yoke) 24 and a permanent magnet 26. Shaft stub ends
`28, 30 are connected with the coil flux guide 24 at both shaft
`ends of the coil flux guide 24 (the bond being resistant to
`torsion). The shaft stub ends 28, 30 are preferably hardened
`steel pins, but can be manufactured from any other suitable
`material. A continuous shaft (not illustrated) on which the
`rotor coil flux guide is mounted in the usual manner can be
`fitted as an alternative to the illustrated embodiment.
`
`[0021] The electric motor 20 also includes a stator 32 with
`a stator body 34 and phase windings 36. The stator body 34
`can be designed as a laminated sheet stack.
`
`[0022] The entire stator 32 is enclosed in an injection(cid:173)
`molded plastic material which forms a plastic body 38. FIG.
`1 indicates that the plastic body 38 forms a chamber for
`receiving the stator 22, the first shaft end 40 of which is
`enclosed (see right of figure). The chamber formed by the
`plastic body 38 is open at the second opposite shaft end 42.
`A bearing seat 44 is formed at the second shaft end 42 which
`holds a roller bearing 46 (preferably a ball bearing). The
`roller bearing 46 supports the rotor 22 in the plastic body 38.
`
`[0023] Ajournal bearing (or hydrodynamic fluid bearing)
`is fitted between the shaft stub end 30 and the sleeve 48 at
`the first shaft end 40 to support the rotor 22, the sleeve being
`integrated in the shaft end 40 of the plastic body 38. It is
`advantageous if the shaft stub end 30 is manufactured from
`hardened steel when forming this journal bearing. Hydro(cid:173)
`dynamic fluid bearings are known in the prior art, and
`examples are described in U.S. Pat. No. 4,934,8636. The
`shaft can consist of another softer material if other types of
`bearing are utilized.
`
`[0024] A magnetic disk 50 is mounted on the shaft end of
`the rotor 22 at the first shaft end 40 which acts as a signal
`transducing sensor for recording the position and speed of
`the rotor 22. A sensor PCB 52 is fitted opposite the magnetic
`disk 50 outside the plastic body 38 which can support Hall
`elements or other sensors for recording the rotational posi(cid:173)
`tion and/or speed of the rotor relative to the magnetic disk
`50.
`
`[0025] An electronic module is fitted outside the first shaft
`end 40 of the plastic body 38 which is generally designated
`54. This is used for electric motor 20 control and power
`supply. The electronic module 54 can include a buffer
`capacitor 56, interference suppressor 58, FET power tran-
`
`sistors 60 and connection pins 62 for establishing electrical
`connections for motor phases. These take the form of metal
`lugs in the illustrated embodiment. The electronic module 54
`also encompasses connection pins 64, 64' which protrude
`outwards for connecting the electric motor 20 to a positive
`and negative power supply connection, one of the connec(cid:173)
`tion pins 64 being directly connected to the interference
`suppressor 38 (as shown in FIG. 1).
`
`[0026] The electronic module is enclosed between the
`plastic body 38 and a cover 66, the cover 66 being sealed
`against the plastic body 38 with an 0-ring 68 or another
`suitable seal. A further 0-ring seal 70 is fitted between the
`plastic body 38 and the pump housing 10. A supporting
`component 72 is fitted in the cover 66 which aids exact
`positioning and support of various components in the elec(cid:173)
`tronic module (e.g. connection pins 64, 64', capacitors 56
`and similar). The supporting component 72 is sealed against
`the cover 66 with a further 0-ring seal 74.
`
`[0027] As mentioned, the stator 32 is completely inte(cid:173)
`grated in the plastic body 38 by injection molding, the
`plastic body being closed at the first shaft end 40. The plastic
`body 38 closed on one side should preferably be manufac(cid:173)
`tured as a single component in one injection molding
`procedure. The plastic body 38 insulates the entire electro(cid:173)
`mechanical module against the medium conveyed by the
`pump and protects the stator module 32 against any envi(cid:173)
`ronmental influences. The stator 32, stator body 34 and
`phase winding 36 circuit is preferably completed before
`being encased in the molding, with only the phase connec(cid:173)
`tions (or three connections in the case of a three-phase
`motor) protruding from the plastic body 38 (but not the
`individual winding wires 36).
`
`[0028] According to the invention, it is preferable that
`other functions be integrated in the plastic body 38 (e.g.
`bearing seats and fixing elements for connecting the plastic
`body 38 to the pump housing 10). The plastic body 38 can
`also be used to position and fix the sensor PCB 52 and the
`electronic module 54 (or parts thereof). It can also be
`beneficial if metal parts are integrated in the plastic body 38
`(particularly in its exterior) in order to shield the motor
`against outward influences. Metal particles, a metal grid or
`similar can be integrated directly in the plastic body 38
`during the injection molding process.
`
`[0029] The main function of the plastic body 38, however,
`is a complete sealed separation of the chamber for receiving
`the rotor 22 which is accessible to the pumping medium
`from all electromechanical components.
`
`[0030]
`In order to compare the electric motor according to
`the invention with known canned motors of the prior art, it
`is necessary to consider the plastic body 38 in which the
`stator is embedded as assuming the function of the can and,
`simultaneously, at least partially acting as a housing for
`positioning other electric motor components and for fixing
`the electric motor 20 to the pump housing 10. The plastic
`body also protects the stator module against exterior en vi(cid:173)
`ronmental influences.
`
`[0031] The invention can be used on both internal rotor
`and external rotor motors.
`
`[0032] The plastic body 38 could also replace the pump
`housing 10 (or part thereof) in any further embodiment of
`the invention by connecting the pump impeller (not illus-
`
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`US 2004/0108779 Al
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`Jun. 10,2004
`
`3
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`trated) directly to the rotor 22 and receiving it in the plastic
`body 38 (i.e. a housing for the pump impeller can be joined
`directly to the plastic body 38 through injection molding or
`designed as a single part together with the plastic body).
`
`In the embodiment illustrated in FIG. 1, the coil
`[0033]
`flux guide (yoke) 24 of the rotor 22 at least partially takes
`over the function of the shaft, so it is preferable that
`hardened steel pins be used as shaft stub ends 28, 30. Such
`hardened steel pins are particularly practical when designing
`one or both bearings as journal bearings (as is the case with
`48). Hardened pins are available commercially as ready(cid:173)
`made components. A continuous shaft can, of course, be
`used as an alternative.
`
`[0034] The embodiment of the coil flux guide 24 of in
`FIG. 1 has the further advantage of facilitating the integra(cid:173)
`tion of ball bearings (such as bearing 46) in the coil flux
`guide 24. The coil flux guide 24 can, in particular, be
`designed with an exterior diameter which allows adaptation
`of the bearing size to the internal diameter of the plastic
`body 38. The same function would require that a shaft with
`an extremely large diameter be provided if a continuous
`shaft with a fitted coil flux guide is used.
`
`[0035] The rotor 22 with the coil flux guide 24 and
`permanent magnet 26 is designed with as smooth as possible
`a surface to avoid or reduce as completely as possible any
`disturbance of the pumping medium in the chamber
`enclosed by the plastic body 38 upon rotation of the rotor.
`
`[0036] FIG. 2 illustrates a sectional view of an alternative
`electric motor embodiment in accordance with the inven(cid:173)
`tion. The same or similar components (as in FIG. 1) bear the
`same reference numbers and are not explained here again.
`The electronic module 54 and cover 66 are not shown in
`FIG. 2. They can be designed as illustrated in FIG. 1 or
`differently.
`
`[0037] The embodiment in FIG. 2 mainly differs from
`FIG. 1 in that the stator 32 is encased in an injection-molded
`plastic body 80 which is open at both shaft ends 40, 42. The
`plastic body 80 is closed by a cover 82 at the first shaft end
`40 (which should preferably also be plastic). A sealed
`connection of the cover 82 and plastic body 80 is realized
`with screws 84 or another fixing agent. The cover 82 is
`sealed against the plastic body 38 with an 0-ring 90 or
`another suitable sealing.
`
`[0038] Furthermore, the rotor 22 in FIG. 2 is supported in
`the plastic body 30 on a shaft 86 by roller bearing 46 and a
`further roller bearing 88.
`
`[0039] On the embodiment in FIG. 2, the motor shaft 86
`with the pre-mounted rotor 20 and bearings 46, 86 can be
`pushed into the plastic body 38, in the drawing from the right
`hand side, this then being sealed with the cover 82. The
`cover 82 fixes the shaft 86 in an axial direction with the
`external ring of the roller bearing 88.
`
`[0040] A sensor PCB (not illustrated in FIG. 2) can be
`pre-mounted on the cover 82 with Hall elements or other
`sensors for recording the rotary position and rotational speed
`of the rotor 22. A magnetic disk 50 is mounted on the first
`shaft end 40 of the rotor 22 for this purpose in the embodi(cid:173)
`ment in FIG. 1. It transmits commutation signals through
`the wall of the cover 82 to the sensor PCB.
`
`[0041] The roller bearing 46, preferably a ball bearing,
`aids accurate centering of the motor on the pump housing
`10. This ball bearing 46 can assume both the motor support
`and pump support functions. The same applies to the ball
`bearing 46 in accordance with FIG. 1, but the second
`bearing in FIG. 1 is designed as a journal bearing 48.
`[0042] FIG. 3 illustrates a dismantled perspective view of
`the electric motor of FIG. 1 according to the present
`invention. The same or similar components are designated
`with the same reference numbers. FIG. 3 illustrates a
`general view of the rotor 22, stator 32, the electronic module
`54 and the supporting part 72, already described with
`reference to FIG. 1. It can be seen in FIG. 3 that the plastic
`body 38 forms a chamber closed on one side for receiving
`the rotor 22, this chamber being closed by a wall 92 at the
`first shaft end 40 which is shaped to receive the shaft stub
`end 30 and journal bearing sleeve 48. The sensor PCB 52 is
`fitted to the wall 92 (which supports connection pins 94).
`The connection pins 94 can be connected to a plug 96 which
`connects the sensors on the sensor PCB 52 with the other
`components in the electronic module 54. The electronic
`module 54 can, as illustrated in FIG. 1, be mounted on a
`single PCB or several levels (or two PCB's 98, 100). The
`transistors 60 can be arranged and connected so that their
`connection legs penetrate at least in part the upper PCB 100
`and can be directly connected to the lower PCB 98. Refer(cid:173)
`ence is made to the German patent application 102 39 512.8
`of 28 Aug. 2002 with regard to the structure of the electronic
`module.
`In a preferred embodiment, the connection pins 62
`[0043]
`directly connected to the phase windings 36 of the stators 32
`are connected to the electronic module 54 by metal lugs 102.
`The metal lugs 102 and connection pins 62 are pressed
`against the cover after assembling the different electric
`motor 20 components and can be attached with a welding
`tongs.
`[0044] The electronic module 54 (or parts thereof) could
`be fitted outside the electric motor in an alternative embodi(cid:173)
`ment. The sensors on the sensor PCB 52 and the electronic
`module 54 could also be combined.
`[0045] The invention is ideally intended for use with a
`completely sealed electric motor which contains the elec(cid:173)
`tronics required for motor control, so that only power supply
`connections in the form of connection pins 64, 64' protrude
`to the exterior. The positive supply connection 64 should be
`connected directly to the interference suppresser 58 in the
`embodiment illustrated, creating a mechanical spring sup(cid:173)
`port of the connection pin 64 which facilitates insertion of
`the connection pin 64 in the supporting component 72. The
`interference suppressor 54 therefore has a mechanical sup(cid:173)
`port function in addition to its electrical function, allowing
`a degree of movement of the connection pin 64. The other,
`negative supply connection 64' can be coupled with one of
`the metal lugs 102 via a cable length 104 to connect the
`phases 36 of the stators 32. Both connection pins 64 and 64'
`have openings 65 which interact with the corresponding
`engaging elements (not illustrated) in the supporting com(cid:173)
`ponent 72.
`[0046]
`It is, of course, also possible to connect other leads
`for electric motor control from outside with the electronic
`module 54 and lead these towards the outside.
`[0047]
`In addition to the representation in FIG. 1, FIG. 3
`shows 0-rings 106, 108 for sealing the roller bearing 46
`
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`Jun. 10,2004
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`4
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`against the plastic body 38 or the supporting component 72
`against the cover 66. Moreover, a groove 110 is illustrated
`on the second shaft end 42 of the plastic body 38 for
`receiving the 0-ring 70.
`
`[0048] The components in the electronic module 54 are
`connected via the metal tabs 102 and other metal rails fitted
`to the PCB 100, as shown on the embodiment illustrated in
`FIG. 3. These PCB tracks can be realized as lead frames or
`as individual connection elements.
`
`[0049] FIGS. 4A and 4B show a side view and a per(cid:173)
`spective representation, respectively, of the plastic body 80
`mounted on the pump housing 10. Only the connection pins
`62 for the three phase required for the phase windings 36 of
`the stator 32 protrude from the plastic body 80, as illustrated
`in FIGS. 4A and 4B. The embodiment illustrated in FIGS.
`4A, 4B corresponds with the drawing in FIG. 2, so that the
`plastic body 80 is closed at the first shaft end 40 by the cover
`82. The cover 82 is fitted to the plastic body 80 with screws
`84. FIGS. 4A, 4B also illustrate that the plastic body 80 is
`shaped with fixing agent 12 to form a flange to connect the
`plastic body 80 directly to the pump housing 10.
`
`[0050] FIGS. SA, 5B show the rotor 22 of the electric
`motor in FIG. 1 in both a dismantled view and an overall
`perspective view, respectively. Identical or similar compo(cid:173)
`nents as in FIG. 1 are designated with the same identifica(cid:173)
`tion reference.
`
`[0051] The invention is used in particular as a power for
`the auxiliary hydraulic steering assistance in vehicles, but is,
`in principle, suitable for use as a pump motor or as a
`wet-rotor motor for a variety of applications.
`
`[0052] The characteristics disclosed in the above descrip(cid:173)
`tion, claims and the drawings can be significant for the
`realization of the invention, either individually or in any
`combination whatsoever.
`
`Identification Reference List
`
`[0070] 54 Electronic module
`
`[0071] 56 Buffer capacitor
`
`[0072] 58 Interference suppressor
`
`[0073] 60 FET power transistor
`
`[0074] 62, 64, 64' Connection pins
`
`[0075] 65 Outlet
`
`[0076] 66 Cover
`
`[0077] 68, 70 0-ring
`
`[0078] 72 Supporting component
`
`[0079] 74 0-ring
`
`[0080] 80 Plastic element
`
`[0081] 82 Cap
`
`[0082] 84 Screw
`
`[0083] 86 Shaft
`
`[0084] 88 Roller bearing
`
`[0085] 90 0-ring
`
`[0086] 92 Wall
`
`[0087] 94 Connecting pins
`
`[0088] 96 Plug
`
`[0089] 98, 100 PCB's
`
`[0090] 102 Metal lugs
`
`[0091] 104 Cable piece
`
`[0092] 106, 108 0-rings
`
`[0093] 110 Slot
`
`[0094] 112 Fixing agent
`
`[0053] 10 Pump housing
`
`[0054] 20 Electrical motor
`
`[0055] 22 Rotor
`
`[0056] 24 Coil flux guide, yoke
`
`[0057] 26 Permanent magnet
`
`[0058] 28, 30 Shaft stub end
`
`[0059] 32 Stator
`
`[0060] 34 Stator component
`
`[0061] 36 Phase winding
`
`[0062] 38 Plastic body
`
`[0063] 40 First shaft end
`
`[0064] 42 Second shaft end
`
`[0065] 44 Bearing seat
`
`[0066] 46 Roller bearing
`
`[0067] 48 Journal bearing sleeve
`
`[0068] 50 Magnetic disk
`
`[0069] 52 Sensor PCB
`
`1. Electric motor for a pump drive, including a stator and
`a rotor for driving a pump impeller, the stator being embed(cid:173)
`ded in a plastic body and the plastic body forming a chamber
`together with the stator in which the rotor is received, the
`chamber being closed at one shaft end of the rotor and the
`rotor being connected at the opposite second shaft end to the
`pump impeller.
`2. Electric motor according to claim 1, wherein the plastic
`body is manufactured by injection molding.
`3. Electric motor according to claim 1, wherein the plastic
`body which surrounds the stator forms a chamber closed at
`the first shaft end, integrally formed in one molding proce(cid:173)
`dure.
`4. Electric motor according to claim 1, wherein the plastic
`body which surrounds the stator forms a chamber open at
`both shaft ends which is closed with a cover at the first shaft
`end.
`5. Electric motor according to claim 3, wherein a bearing
`seat for receiving a roller bearing to support the rotor is
`integrated in an interior wall of the chamber at the second
`shaft end.
`6. Electric motor according to claim 4, wherein a bearing
`seat for receiving a roller bearing to support the rotor is
`integrated in an interior wall of the chamber at the second
`shaft end.
`
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`Jun. 10,2004
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`5
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`7. Electric motor according to claim 3, wherein the rotor
`is fitted on a shaft which is supported by a journal bearing
`at the first shaft end.
`8. Electric motor according to claim 4, wherein the rotor
`is fitted on a shaft which is supported by a journal bearing
`at the first shaft end.
`9. Electric motor according to claim 1, wherein the rotor
`is equipped with a coil flux guide connected to shaft stub
`ends at both shaft ends.
`10. Electric motor according to claim 1, wherein the stator
`has a stator core and phase windings, each connected to a
`connection element for each phase, the plastic body sur(cid:173)
`rounding the wound stator in a manner which allows only
`the connection element to be accessible.
`11. Electric motor according to claim 8, wherein the rotor
`received in the chamber when operating the electrical motor
`in connection with a pump is immersed in the pumping
`medium.
`
`12. Electric motor according to claim 8, characterized by
`an electronic module for electrical motor actuation which is
`located outside the chamber.
`13. Electric motor according to claim 10, wherein the
`electronic module is separated from the pumping medium by
`the plastic body.
`14. Electric motor according to claim 10, wherein the
`connection element for each phase of the electrical motor
`has a contact lug, and the electronic module has suitable
`contact lugs, these coming to rest next to the connection
`element contact lugs for connection thereof.
`15. Electric motor according to claim 1, wherein at least
`part of the plastic body has metal parts integrated in it to
`shield the electrical motor against outside influences.
`
`* * * * *
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`PAGE 11 OF 11
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