WO2023057074A1 - Automotive electric fluid pump - Google Patents
Automotive electric fluid pump Download PDFInfo
- Publication number
- WO2023057074A1 WO2023057074A1 PCT/EP2021/077893 EP2021077893W WO2023057074A1 WO 2023057074 A1 WO2023057074 A1 WO 2023057074A1 EP 2021077893 W EP2021077893 W EP 2021077893W WO 2023057074 A1 WO2023057074 A1 WO 2023057074A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- separating
- bottom wall
- clamping
- fluid pump
- electric fluid
- Prior art date
Links
- 239000012530 fluid Substances 0.000 title claims abstract description 41
- 230000005670 electromagnetic radiation Effects 0.000 abstract description 7
- 239000002184 metal Substances 0.000 description 5
- 230000005294 ferromagnetic effect Effects 0.000 description 4
- 238000005452 bending Methods 0.000 description 3
- 230000007704 transition Effects 0.000 description 2
- 239000002826 coolant Substances 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D13/00—Pumping installations or systems
- F04D13/02—Units comprising pumps and their driving means
- F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
- F04D13/0606—Canned motor pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
- F04D29/426—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for liquid pumps
Definitions
- the present invention is directed to an automotive electric fluid pump with a so-called canned electric motor, in particular to an automotive electric coolant pump.
- Canned electric motors comprise a separating can with a cylindrical separating can sidewall which extends through a gap between a motor stator and a motor rotor of the electric motor.
- the separating can fluidically separates the generally moisture-sensitive electromagnetic motor stator from the generally moisture-insensitive permanent-magnetic motor rotor.
- EMC electromagnetic compatibility
- WO 2019/101304 Al discloses an automotive electric fluid pump comprising a canned electric motor with a metallic separating can, wherein an electrically conductive separating-can grounding element is provided which is configured to electrically connect the separating can with a ground potential of the automotive fluid pump.
- the metallic separating can thus serve as an electromagnetic shielding which allows to significantly reduce the amount of electromagnetic radiation being radiated from the electric motor.
- the disclosed spring-type separating-can grounding element can loose electric contact with the separating can if the automotive electric fluid pump is exposed to relatively strong vibrations or to vibrations with an unfavorable frequency. This can cause, at least temporarily, an excessive amount of electromagnetic radiation being radiated from the electric motor.
- An object of the present invention is therefore to provide an automotive electric fluid pump with constantly low electromagnetic radiation.
- the automotive electric fluid pump according to the present invention is provided with a canned electric motor comprising an electromagnetic motor stator, a permanent-magnetic motor rotor and a pot-shaped metallic separating can which flu id ically separates the motor stator from the motor rotor.
- the motor stator comprises a ferromagnetic stator body and at least one stator coil.
- the stator body is preferably a so-called laminated stator body which means that the stator body is composed of a stack of ferromagnetic metal sheets.
- the motor stator is arranged on a dry side of the separating can, and the motor rotor is arranged at a fluid-filled wet side of the separating can and is co-rotatably connected with a pump wheel.
- the pot-shaped separating can comprises a cylindrical separating can sidewall which extends through the cylindrical gap defined between the motor stator and the motor rotor.
- the pot-shaped separating can also comprises a transverse separating can bottom wall which extends substantially transverse to the axial direction of the cylindrical separating can sidewall and which is fluid-tightly connected with the separating can sidewall.
- the separating can is also provided with a pot-shaped bottom wall protrusion which axially protrudes from the separating can bottom wall at a motor-rotor-remote axial side.
- a rotor shaft bearing or a rotor support pin is arranged within the pot-shaped bottom wall protrusion.
- the complete separating can is preferably made in one piece, e.g., by deep-drawing a metal sheet.
- an axial direction is parallel to the axial direction of the cylindrical separating can sidewall
- a radial direction is perpendicular to the axial direction of the cylindrical separating can sidewall
- transverse means transverse to the axial direction of the cylindrical separating can sidewall
- the automotive electric fluid pump according to the present invention is also provided with an electrically conductive separating-can grounding element which is configured to electrically connect the separating can with a ground potential.
- the separating-can grounding element can be, for example, configured to electrically connect the separating can to a ground terminal of a motor electronics. It is also possible that the separating-can grounding element is configured to electrically connect the separating can with a ground wire of an external connector cable or with a ground lug of an external connector plug of the automotive electric fluid pump.
- the separating-can grounding element is provided with a clamping arrangement which is in touching contact with a radial outside surface of the bottom wall protrusion.
- the clamping arrangement is configured in such a way that the bottom wall protrusion is radially clamped within the clamping arrangement, i.e., the clamping arrangement comprises clamping elements which are designed and arranged in such a way that each clamping element radially pushes the bottom wall protrusion against at least one other clamping element.
- the clamping elements are preferably elastically deformed when the bottom wall protrusion is inserted into the clamping arrangement so that the clamping elements are radially preloaded against the radial outside surface of the bottom wall protrusion.
- the clamping arrangement provides a reliable contact with the bottom wall protrusion and thus a reliable electrical grounding of the separating can even in case of strong and unfavorable vibrations.
- the automotive electric fluid pump according to the present invention therefore provides constantly low electromagnetic radiation.
- the clamping arrangement comprises at least three clamping elements which are - preferably substantially equidistantly - distributed along a circumferential direction of the radial outside surface of the bottom wall protrusion.
- the at least three distributed clamping elements have the effect that the bottom wall protrusion is always pressed against at least one of the clamping elements, regardless of the actual movement direction, if the bottom wall protrusion moves radially with respect to the clamping arrangement, e.g., due to vibrations. This ensures that the bottom wall protrusion is always in electrical contact with at least one of the clamping elements, which in turn provides a reliably electrical grounding of the separating can.
- the clamping arrangement comprises a connection ring to which all clamping elements are attached.
- the clamping elements are preferably attached to a radial inside of the connection ring.
- the connection ring provides a mechanically stable clamping arrangement which provides a reliably electrical grounding of the separating can.
- each clamping element comprises an axial clamping element leg which is shaped such that a separating-can-bottom-wall-sided axial end of the axial clamping element leg is located more radially outward compared to a separating-can-bottom-wall-remote axial end of the axial clamping element leg if the clamping element is unstressed.
- the clamping elements are preferably substantially L-shaped, wherein a radial clamping element leg is located at the separating-can-bottom-wall-remote axial end of the axial clamping element leg. This provides a reliable contact between the clamping element and the bottom wall protrusion within a separating-can-bottom-wall-remote end region of the axial clamping element leg.
- the clamping arrangement comprises two clamping elements which are arranged at opposite sides of the bottom wall protrusion in such a way that orthogonal projections of the two clamping elements onto a straight line, which is perpendicular to a distance vector between the two clamping elements and perpendicular to an axial direction of the bottom wall protrusion, do not completely overlap.
- the two clamping elements are displaced into opposite lateral directions with respect to a centerline of the bottom wall protrusion which is parallel to the distance vector.
- the lateral displacement between the two clamping elements is preferably substantially equal to half a lateral width of the clamping elements so that a bottom-wall-protrusion-sided lateral clamping element edge of each clamping element is arranged substantially opposite a lateral center of the respective other clamping element.
- the bottom wall protrusion slides along the first clamping element if the bottom wall protrusion moves into the first lateral direction with respect to the clamping arrangement, and slides along the second clamping element if the bottom wall protrusion moves into the second lateral direction with respect to the clamping arrangement. If the bottom wall protrusion moves perpendicular to the lateral directions with respect to the clamping arrangement, it is either pressed against the first clamping element or against the second clamping element. This ensures that the bottom wall protrusion is always in electrical contact with at least one of the clamping elements, which in turn provides a reliably electrical grounding of the separating can.
- the two clamping elements are provided with a substantially rectangular cross-section in a transverse plane. This allows the clamping arrangement and thus the separating-can grounding element to be easily and cost-effectively manufactured from a metal sheet via stamping and bending.
- a separating-can-bottom-wall-sided axial end of each clamping element is provided with rounded lateral clamping element edges in such a way that a rounding radius of a bottom-wall-protrusion-sided lateral clamping element edge is larger than a rounding radius of a bottom-wall-protrusion-remote lateral clamping element edge.
- the lateral clamping element dimension in this context is that dimension which is perpendicular to the distance vector between the two clamping elements and perpendicular to the axial direction of the bottom wall protrusion.
- the rounding radius of the bottom-wall-protrusion-sided lateral clamping element edges is preferably substantially equal to half the lateral width of the clamping element. The relatively large rounding radius of the bottom-wall-protrusion-sided lateral clamping element edges allows the bottom wall protrusion to be easily and reliably inserted into the clamping arrangement.
- each clamping element is provided with a clamping element opening.
- the clamping element opening is preferably arranged at a lateral center of the respective clamping element and provided with an elongated shape, wherein the longitudinal direction is parallel to the axial direction of the bottom wall protrusion.
- the clamping element opening increases the bendability of the clamping element and thus allows the bottom wall protrusion to be easily and reliably inserted into the clamping arrangement.
- the automotive electric fluid pump according to the present invention comprises an external connector plug, wherein the separating-can grounding element comprises a connector lug part which is arranged within the external connector plug.
- the separating-can grounding element comprises a connector lug part which is arranged within the external connector plug.
- the separating-can grounding element is a single-piece stamped part which can be easily and cost-effectively manufactured from a metal sheet via stamping and bending.
- the automotive electric fluid pump according to the present invention comprises a plastic motor housing element which defines at least a transverse motor housing bottom wall extending substantially parallel to the separating can bottom wall, wherein the separating-can grounding element is embedded into the motor housing element.
- the plastic motor housing element is typically made by injection molding, wherein the separating-can grounding element is inserted into the mold before the mold is filled with plastic. This allows the separating-can grounding element to be very reliably and exactly positioned within the motor housing element and thus with respect to the separating can. This in turn provides a reliable electrical contact between the clamping arrangement and the bottom wall protrusion.
- the clamping arrangement is embedded into the motor housing element in such a way that the connection ring is embedded into the motor housing element and that the clamping elements protrude out of the motor housing element.
- the embedded connection ring provides a mechanically stable attachment of the clamping arrangement to the motor housing element, and the protruding clamping elements provide a reliable electrical contact with the bottom wall protrusion.
- the clamping elements and the motor housing element are preferably designed in such a way that the clamping elements can be slightly bent by the bottom wall protrusion. Due to the bending, the clamping elements are preloaded toward the bottom wall protrusion which provides a reliable electrical contact between the clamping elements and the bottom wall protrusion.
- the transition region between an axially extending cylindrical sidewall of the bottom wall protrusion and a transverse bottom wall of the bottom wall protrusion is typically rounded.
- the motor housing bottom wall therefore preferably comprises a recess within which a separating-can-bottom-wall-remote axial end of the bottom wall protrusion, at which the bottom wall of the bottom wall protrusion is located, is arranged. This ensures that the clamping arrangement is in contact with the cylindrical sidewall of the bottom wall protrusion and not with the rounded transition region between the sidewall and the bottom wall of the bottom wall protrusion, which in turn provides a reliable electrical contact between the clamping arrangement and the bottom wall protrusion.
- figure 1 shows a sectioned view of an electric motor part of an automotive electric fluid pump according to the present invention
- figure 2 shows an enlarged view of a clamping arrangement of a separating-can grounding element of the automotive electric fluid pump of figure 1
- figure 3 shows a top view of a transverse housing bottom wall of the automotive electric fluid pump of figure 1, into which the separating-can grounding element is embedded
- figure 4 shows an enlarged view of the clamping arrangement of the separating-can grounding element of figure 3
- figure 5 shows a clamping arrangement of an alternative separating-can grounding element
- figure 6 shows a side view on a front side of a clamping element of the clamping arrangement of figure 5.
- Fig. 1 shows an automotive electric fluid pump 10 with a canned electric motor 12 which is arranged within a plastic motor housing element 14.
- the automotive electric fluid pump 10 comprises an external connector plug 16 which is arranged at a motor housing bottom wall 18, wherein a plug housing 20 is formed integrally with the motor housing element 14.
- the canned electric motor 12 comprises an electromagnetic motor stator 22 with a ferromagnetic stator body 24 and a plurality of stator coils 26.
- the stator body 24 is composed essentially of a stack of ferromagnetic metal sheets.
- the canned electric motor 12 comprises a permanent-magnetic motor rotor 28 with a substantially cylindrical, permanent-magnetic drive section 30 and with a pump-wheel section 32 which defines a pump wheel of the automotive electric fluid pump 10.
- the motor rotor 28 is rotatably supported by a rotor support pin 34.
- the canned electric motor 12 comprises a one-piece, substantially pot-shaped metallic separating can 36 which flu id ically separates the motor stator 22 from the motor rotor 28.
- the separating can 36 comprises a substantially ring-shaped mounting flange 38 via which the separating can 36 is attached to the motor housing element 14.
- the separating can 36 comprises a substantially cylindrical separating can sidewall 40 which extends through a gap between the motor stator 22 and the motor rotor 28.
- the separating can 36 comprises a transverse separating can bottom wall 42 which extends substantially parallel to the motor housing bottom wall 18.
- the separating can 36 comprises a substantially pot-shaped bottom wall protrusion 44 which axially protrudes from the separating can bottom wall 42 at a motor-rotor-remote axial side.
- the bottom wall protrusion 44 supports the rotor support pin 34, wherein an axial end of the rotor support pin is press-fit into the bottom wall protrusion 44.
- the automotive electric fluid pump 10 comprises three electrically conductive stator coil connecting elements 46 and an electrically conductive separating-can grounding element 48 which are each single-piece stamped parts and embedded into the motor housing bottom wall 18 of the motor housing element 14.
- the stator coil connecting elements 46 and the separating-can grounding element 48 each comprise a connector lug part 50 which is arranged within the plug housing 20 of the external connector plug 16 so as to allow an external electrical connection to the respective element 46,48 via the external connector plug 16.
- Each stator coil connecting element 46 is electrically connected to at least one of the stator coils 26 so that the respective stator coil 26 can be externally electrically energized via the external connector plug 16 by an external motor electronics.
- the automotive electric fluid pump 10 does not comprise any internal motor electronics for energizing the stator coils 26.
- the separating-can grounding element 48 comprises a clamping arrangement 52 which is in touching radial contact with a radial outside surface 54 of the bottom wall protrusion 44.
- the clamping arrangement 52 comprises a connection ring 56 and three clamping elements 58 which are equidistantly distributed along the circumference of the outside surface 54 and attached to the connection ring 56.
- the connection ring 56 is completely embedded into the housing bottom wall 18 of the motor housing element 14 and the clamping elements 58 protrude out of the housing bottom wall 18.
- the clamping elements 58 are each substantially L-shaped with a radial clamping element leg 60 and an axial clamping element leg 62, wherein the axial clamping element leg 62 of each clamping element 58 is shaped such that a separating-can-bottom-wall-sided axial end 64 of the axial clamping element leg 62 is located more radially outward compared to a separating-can-bottom-wall-remote axial end 66 of the axial clamping element 62 if the clamping element 58 is unstressed.
- the housing bottom wall 18 of the motor housing element 14 is provided with a central recess 68 within which a separating-can-bottom-wall-remote axial end 70 of the bottom wall protrusion 44 is arranged.
- the external connector plug 16 of the automotive electric fluid pump 10 is specified for electrically connecting the connector lug 50 of the separating-can grounding element 48 to an external ground potential.
- Fig. 5 shows a clamping arrangement 52' of an alternative separating-can grounding element 48' for the automotive electric fluid pump 10. To denote features of the separating-can grounding element 48' which are already known from the separating-can grounding element 48, the respective reference numerals of figures 1 to 4 are used with an additional apostrophe character.
- the separating-can grounding element 48' is also a single-piece stamped part, is also embedded into the motor housing bottom wall 18 of the motor housing element 14, and also comprises a connector lug which is arranged within the connector plug 16 for electrical connection of the separating-can grounding element 48' to the external ground potential.
- the separating-can grounding element 48' mainly differs from the separating-can grounding element 48 in that the separating-can grounding element 48' comprises only two clamping elements 58' which are arranged at opposite sides of the bottom wall protrusion 44.
- the two clamping elements 58' are displaced with respect to a distance vector D between the two clamping elements 58' into opposite lateral direction such that the orthogonal projections P1,P2 of the two clamping elements 58' onto a straight line L, which is perpendicular to the distance vector D and perpendicular to an axial direction of the bottom wall protrusion 44, do not completely overlap.
- the two clamping elements 58' each have a substantially rectangular cross-section in a transverse plane and are each provided with an elongated clamping element opening 72.
- the clamping element opening 72 is arranged centered with respect to a lateral dimension of the respective clamping element 58, the lateral dimension of the clamping element 58' being that dimension which is perpendicular to the distance vector D and to the axial direction of the bottom wall protrusion 44.
- the clamping element opening 72 has an elongated shape, with the longitudinal direction being parallel to the axial direction of the bottom wall protrusion 44.
- a separating-can-bottom-wall-sided axial end 74 of each clamping element 58' is provided with rounded lateral clamping element edges 76,78, wherein a rounding radius R.1 of a bottom-wall-protrusion-sided lateral clamping element edge 76 of each clamping element 58' is substantially equal to one-half a lateral width of the clamping element 58' and a rounding radius R.2 of a bottom-wall-protrusion-remote lateral clamping element edge 78 of each clamping element 58' is substantially equal to one-quarter the lateral width of the clamping element 58'.
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Abstract
The present invention is directed to an automotive electric fluid pump (10) with: - an electromagnetic motor stator (22), - a permanent-magnetic motor rotor (28), - a pot-shaped metallic separating can (36) comprising: a cylindrical separating can sidewall (40) which extends through a cylindrical gap between the motor stator (22) and the motor rotor (28), and a transverse separating can bottom wall (42) with a bottom wall protrusion (44) which axially protrudes from the separating can bottom wall (42) at a motor-rotor-remote axial side, and - an electrically conductive separating-can grounding element (48;48') which is configured to electrically connect the separating can (36) with a ground potential, and which comprises a clamping arrangement (52;52') which is in touching contact with a radial outside surface (54) of the bottom wall protrusion (44). The separating-can grounding element (48;48') with the clamping arrangement (52;52') provides a reliable electrical grounding of the separating can (36) so that the automotive electric fluid pump (10) according to the present invention has constantly low electromagnetic radiation.
Description
D E S C R I P T I O N
Automotive electric fluid pump
The present invention is directed to an automotive electric fluid pump with a so-called canned electric motor, in particular to an automotive electric coolant pump.
Canned electric motors comprise a separating can with a cylindrical separating can sidewall which extends through a gap between a motor stator and a motor rotor of the electric motor. The separating can fluidically separates the generally moisture-sensitive electromagnetic motor stator from the generally moisture-insensitive permanent-magnetic motor rotor.
Due to the alternating energization of the electromagnetic motor stator, electric motors generally generate electromagnetic radiation, which can cause malfunction or failure of electronic devices in vicinity of the electric motor. As a consequence, devices with electric motors have to comply with certain electromagnetic compatibility (EMC) directives which define a maximum allowed amount of electromagnetic radiation for the device.
Against this background, WO 2019/101304 Al discloses an automotive electric fluid pump comprising a canned electric motor with a metallic separating can, wherein an electrically conductive separating-can grounding element is provided which is configured to electrically connect the separating can with a ground potential of the automotive fluid pump. The metallic separating can thus serve as an electromagnetic shielding which allows to significantly reduce the amount of electromagnetic radiation being radiated from the electric motor.
The disclosed spring-type separating-can grounding element, however, can loose electric contact with the separating can if the automotive electric fluid pump is exposed to relatively strong vibrations or to vibrations with an unfavorable frequency. This can cause, at least temporarily, an excessive amount of electromagnetic radiation being radiated from the electric motor.
An object of the present invention is therefore to provide an automotive electric fluid pump with constantly low electromagnetic radiation.
This object is achieved with an automotive electric fluid pump with the features of claim 1.
The automotive electric fluid pump according to the present invention is provided with a canned electric motor comprising an electromagnetic motor stator, a permanent-magnetic motor rotor and a pot-shaped metallic separating can which flu id ically separates the motor stator from the motor rotor.
The motor stator comprises a ferromagnetic stator body and at least one stator coil. The stator body is preferably a so-called laminated stator body which means that the stator body is composed of a stack of ferromagnetic metal sheets. The motor stator is arranged on a dry side of the separating can, and the motor rotor is arranged at a fluid-filled wet side of the separating can and is co-rotatably connected with a pump wheel.
The pot-shaped separating can comprises a cylindrical separating can sidewall which extends through the cylindrical gap defined between the motor stator and the motor rotor. The pot-shaped separating can also comprises a transverse separating can bottom wall which extends substantially transverse to the axial direction of the cylindrical separating can sidewall and which is fluid-tightly connected with the separating can
sidewall. The separating can is also provided with a pot-shaped bottom wall protrusion which axially protrudes from the separating can bottom wall at a motor-rotor-remote axial side. Typically, a rotor shaft bearing or a rotor support pin is arranged within the pot-shaped bottom wall protrusion. The complete separating can is preferably made in one piece, e.g., by deep-drawing a metal sheet.
In the following description, unless otherwise specified, an axial direction is parallel to the axial direction of the cylindrical separating can sidewall, a radial direction is perpendicular to the axial direction of the cylindrical separating can sidewall and transverse means transverse to the axial direction of the cylindrical separating can sidewall.
The automotive electric fluid pump according to the present invention is also provided with an electrically conductive separating-can grounding element which is configured to electrically connect the separating can with a ground potential. The separating-can grounding element can be, for example, configured to electrically connect the separating can to a ground terminal of a motor electronics. It is also possible that the separating-can grounding element is configured to electrically connect the separating can with a ground wire of an external connector cable or with a ground lug of an external connector plug of the automotive electric fluid pump.
According to the present invention, the separating-can grounding element is provided with a clamping arrangement which is in touching contact with a radial outside surface of the bottom wall protrusion. The clamping arrangement is configured in such a way that the bottom wall protrusion is radially clamped within the clamping arrangement, i.e., the clamping arrangement comprises clamping elements which are designed and arranged in such a way that each clamping element radially pushes the bottom wall protrusion against at least one other clamping element. The
clamping elements are preferably elastically deformed when the bottom wall protrusion is inserted into the clamping arrangement so that the clamping elements are radially preloaded against the radial outside surface of the bottom wall protrusion. The clamping arrangement provides a reliable contact with the bottom wall protrusion and thus a reliable electrical grounding of the separating can even in case of strong and unfavorable vibrations. The automotive electric fluid pump according to the present invention therefore provides constantly low electromagnetic radiation.
In a preferred embodiment of the present invention, the clamping arrangement comprises at least three clamping elements which are - preferably substantially equidistantly - distributed along a circumferential direction of the radial outside surface of the bottom wall protrusion. The at least three distributed clamping elements have the effect that the bottom wall protrusion is always pressed against at least one of the clamping elements, regardless of the actual movement direction, if the bottom wall protrusion moves radially with respect to the clamping arrangement, e.g., due to vibrations. This ensures that the bottom wall protrusion is always in electrical contact with at least one of the clamping elements, which in turn provides a reliably electrical grounding of the separating can.
Preferably, the clamping arrangement comprises a connection ring to which all clamping elements are attached. The clamping elements are preferably attached to a radial inside of the connection ring. The connection ring provides a mechanically stable clamping arrangement which provides a reliably electrical grounding of the separating can.
In a preferred embodiment of the present invention, each clamping element comprises an axial clamping element leg which is shaped such that a separating-can-bottom-wall-sided axial end of the axial clamping
element leg is located more radially outward compared to a separating-can-bottom-wall-remote axial end of the axial clamping element leg if the clamping element is unstressed. This allows the bottom wall protrusion to be reliably axially inserted into the clamping arrangement, even if the bottom wall protrusion is not exactly centered with respect to the clamping arrangement. The clamping elements are preferably substantially L-shaped, wherein a radial clamping element leg is located at the separating-can-bottom-wall-remote axial end of the axial clamping element leg. This provides a reliable contact between the clamping element and the bottom wall protrusion within a separating-can-bottom-wall-remote end region of the axial clamping element leg.
In an alternative preferred embodiment of the present invention, the clamping arrangement comprises two clamping elements which are arranged at opposite sides of the bottom wall protrusion in such a way that orthogonal projections of the two clamping elements onto a straight line, which is perpendicular to a distance vector between the two clamping elements and perpendicular to an axial direction of the bottom wall protrusion, do not completely overlap. This means that the two clamping elements are displaced into opposite lateral directions with respect to a centerline of the bottom wall protrusion which is parallel to the distance vector. The lateral displacement between the two clamping elements is preferably substantially equal to half a lateral width of the clamping elements so that a bottom-wall-protrusion-sided lateral clamping element edge of each clamping element is arranged substantially opposite a lateral center of the respective other clamping element. As a result, the bottom wall protrusion slides along the first clamping element if the bottom wall protrusion moves into the first lateral direction with respect to the clamping arrangement, and slides along the second clamping element if the bottom wall protrusion moves into the second lateral direction with respect to the
clamping arrangement. If the bottom wall protrusion moves perpendicular to the lateral directions with respect to the clamping arrangement, it is either pressed against the first clamping element or against the second clamping element. This ensures that the bottom wall protrusion is always in electrical contact with at least one of the clamping elements, which in turn provides a reliably electrical grounding of the separating can.
Preferably, the two clamping elements are provided with a substantially rectangular cross-section in a transverse plane. This allows the clamping arrangement and thus the separating-can grounding element to be easily and cost-effectively manufactured from a metal sheet via stamping and bending.
In a preferred embodiment of the present invention, a separating-can-bottom-wall-sided axial end of each clamping element is provided with rounded lateral clamping element edges in such a way that a rounding radius of a bottom-wall-protrusion-sided lateral clamping element edge is larger than a rounding radius of a bottom-wall-protrusion-remote lateral clamping element edge. The lateral clamping element dimension in this context is that dimension which is perpendicular to the distance vector between the two clamping elements and perpendicular to the axial direction of the bottom wall protrusion. The rounding radius of the bottom-wall-protrusion-sided lateral clamping element edges is preferably substantially equal to half the lateral width of the clamping element. The relatively large rounding radius of the bottom-wall-protrusion-sided lateral clamping element edges allows the bottom wall protrusion to be easily and reliably inserted into the clamping arrangement.
Preferably, each clamping element is provided with a clamping element opening. The clamping element opening is preferably arranged at a lateral
center of the respective clamping element and provided with an elongated shape, wherein the longitudinal direction is parallel to the axial direction of the bottom wall protrusion. The clamping element opening increases the bendability of the clamping element and thus allows the bottom wall protrusion to be easily and reliably inserted into the clamping arrangement.
Preferably, the automotive electric fluid pump according to the present invention comprises an external connector plug, wherein the separating-can grounding element comprises a connector lug part which is arranged within the external connector plug. This allows the separating-can grounding element to be easily and reliably connected to an external ground potential, e.g., a vehicle ground potential, via the external connector plug. This in turn provides a reliable electrical grounding of the separating can.
In a preferred embodiment of the present invention, the separating-can grounding element is a single-piece stamped part which can be easily and cost-effectively manufactured from a metal sheet via stamping and bending.
Preferably, the automotive electric fluid pump according to the present invention comprises a plastic motor housing element which defines at least a transverse motor housing bottom wall extending substantially parallel to the separating can bottom wall, wherein the separating-can grounding element is embedded into the motor housing element. The plastic motor housing element is typically made by injection molding, wherein the separating-can grounding element is inserted into the mold before the mold is filled with plastic. This allows the separating-can grounding element to be very reliably and exactly positioned within the motor housing element and thus with respect to the separating can. This in turn provides
a reliable electrical contact between the clamping arrangement and the bottom wall protrusion.
In a preferred embodiment of the present invention, the clamping arrangement is embedded into the motor housing element in such a way that the connection ring is embedded into the motor housing element and that the clamping elements protrude out of the motor housing element. The embedded connection ring provides a mechanically stable attachment of the clamping arrangement to the motor housing element, and the protruding clamping elements provide a reliable electrical contact with the bottom wall protrusion. The clamping elements and the motor housing element are preferably designed in such a way that the clamping elements can be slightly bent by the bottom wall protrusion. Due to the bending, the clamping elements are preloaded toward the bottom wall protrusion which provides a reliable electrical contact between the clamping elements and the bottom wall protrusion.
The transition region between an axially extending cylindrical sidewall of the bottom wall protrusion and a transverse bottom wall of the bottom wall protrusion is typically rounded. The motor housing bottom wall therefore preferably comprises a recess within which a separating-can-bottom-wall-remote axial end of the bottom wall protrusion, at which the bottom wall of the bottom wall protrusion is located, is arranged. This ensures that the clamping arrangement is in contact with the cylindrical sidewall of the bottom wall protrusion and not with the rounded transition region between the sidewall and the bottom wall of the bottom wall protrusion, which in turn provides a reliable electrical contact between the clamping arrangement and the bottom wall protrusion.
Embodiments of the present invention are described with reference to the enclosed figures, wherein figure 1 shows a sectioned view of an electric motor part of an automotive electric fluid pump according to the present invention, figure 2 shows an enlarged view of a clamping arrangement of a separating-can grounding element of the automotive electric fluid pump of figure 1, figure 3 shows a top view of a transverse housing bottom wall of the automotive electric fluid pump of figure 1, into which the separating-can grounding element is embedded, figure 4 shows an enlarged view of the clamping arrangement of the separating-can grounding element of figure 3, figure 5 shows a clamping arrangement of an alternative separating-can grounding element, and figure 6 shows a side view on a front side of a clamping element of the clamping arrangement of figure 5.
Fig. 1 shows an automotive electric fluid pump 10 with a canned electric motor 12 which is arranged within a plastic motor housing element 14. The automotive electric fluid pump 10 comprises an external connector plug 16 which is arranged at a motor housing bottom wall 18, wherein a plug housing 20 is formed integrally with the motor housing element 14.
The canned electric motor 12 comprises an electromagnetic motor stator 22 with a ferromagnetic stator body 24 and a plurality of stator coils 26. The stator body 24 is composed essentially of a stack of ferromagnetic metal sheets.
The canned electric motor 12 comprises a permanent-magnetic motor rotor 28 with a substantially cylindrical, permanent-magnetic drive section 30 and with a pump-wheel section 32 which defines a pump wheel of the
automotive electric fluid pump 10. The motor rotor 28 is rotatably supported by a rotor support pin 34.
The canned electric motor 12 comprises a one-piece, substantially pot-shaped metallic separating can 36 which flu id ically separates the motor stator 22 from the motor rotor 28. The separating can 36 comprises a substantially ring-shaped mounting flange 38 via which the separating can 36 is attached to the motor housing element 14. The separating can 36 comprises a substantially cylindrical separating can sidewall 40 which extends through a gap between the motor stator 22 and the motor rotor 28. The separating can 36 comprises a transverse separating can bottom wall 42 which extends substantially parallel to the motor housing bottom wall 18. The separating can 36 comprises a substantially pot-shaped bottom wall protrusion 44 which axially protrudes from the separating can bottom wall 42 at a motor-rotor-remote axial side. The bottom wall protrusion 44 supports the rotor support pin 34, wherein an axial end of the rotor support pin is press-fit into the bottom wall protrusion 44.
The automotive electric fluid pump 10 comprises three electrically conductive stator coil connecting elements 46 and an electrically conductive separating-can grounding element 48 which are each single-piece stamped parts and embedded into the motor housing bottom wall 18 of the motor housing element 14. The stator coil connecting elements 46 and the separating-can grounding element 48 each comprise a connector lug part 50 which is arranged within the plug housing 20 of the external connector plug 16 so as to allow an external electrical connection to the respective element 46,48 via the external connector plug 16.
Each stator coil connecting element 46 is electrically connected to at least one of the stator coils 26 so that the respective stator coil 26 can be
externally electrically energized via the external connector plug 16 by an external motor electronics. The automotive electric fluid pump 10 does not comprise any internal motor electronics for energizing the stator coils 26.
The separating-can grounding element 48 comprises a clamping arrangement 52 which is in touching radial contact with a radial outside surface 54 of the bottom wall protrusion 44. The clamping arrangement 52 comprises a connection ring 56 and three clamping elements 58 which are equidistantly distributed along the circumference of the outside surface 54 and attached to the connection ring 56. The connection ring 56 is completely embedded into the housing bottom wall 18 of the motor housing element 14 and the clamping elements 58 protrude out of the housing bottom wall 18.
The clamping elements 58 are each substantially L-shaped with a radial clamping element leg 60 and an axial clamping element leg 62, wherein the axial clamping element leg 62 of each clamping element 58 is shaped such that a separating-can-bottom-wall-sided axial end 64 of the axial clamping element leg 62 is located more radially outward compared to a separating-can-bottom-wall-remote axial end 66 of the axial clamping element 62 if the clamping element 58 is unstressed.
The housing bottom wall 18 of the motor housing element 14 is provided with a central recess 68 within which a separating-can-bottom-wall-remote axial end 70 of the bottom wall protrusion 44 is arranged.
The external connector plug 16 of the automotive electric fluid pump 10 is specified for electrically connecting the connector lug 50 of the separating-can grounding element 48 to an external ground potential.
Fig. 5 shows a clamping arrangement 52' of an alternative separating-can grounding element 48' for the automotive electric fluid pump 10. To denote features of the separating-can grounding element 48' which are already known from the separating-can grounding element 48, the respective reference numerals of figures 1 to 4 are used with an additional apostrophe character.
Like the separating-can grounding element 48, the separating-can grounding element 48' is also a single-piece stamped part, is also embedded into the motor housing bottom wall 18 of the motor housing element 14, and also comprises a connector lug which is arranged within the connector plug 16 for electrical connection of the separating-can grounding element 48' to the external ground potential.
The separating-can grounding element 48' mainly differs from the separating-can grounding element 48 in that the separating-can grounding element 48' comprises only two clamping elements 58' which are arranged at opposite sides of the bottom wall protrusion 44. The two clamping elements 58' are displaced with respect to a distance vector D between the two clamping elements 58' into opposite lateral direction such that the orthogonal projections P1,P2 of the two clamping elements 58' onto a straight line L, which is perpendicular to the distance vector D and perpendicular to an axial direction of the bottom wall protrusion 44, do not completely overlap.
The two clamping elements 58' each have a substantially rectangular cross-section in a transverse plane and are each provided with an elongated clamping element opening 72. The clamping element opening 72 is arranged centered with respect to a lateral dimension of the respective clamping element 58, the lateral dimension of the clamping element 58' being that dimension which is perpendicular to the distance
vector D and to the axial direction of the bottom wall protrusion 44. The clamping element opening 72 has an elongated shape, with the longitudinal direction being parallel to the axial direction of the bottom wall protrusion 44.
A separating-can-bottom-wall-sided axial end 74 of each clamping element 58' is provided with rounded lateral clamping element edges 76,78, wherein a rounding radius R.1 of a bottom-wall-protrusion-sided lateral clamping element edge 76 of each clamping element 58' is substantially equal to one-half a lateral width of the clamping element 58' and a rounding radius R.2 of a bottom-wall-protrusion-remote lateral clamping element edge 78 of each clamping element 58' is substantially equal to one-quarter the lateral width of the clamping element 58'.
Reference List
10 automotive electric fluid pump
12 canned electric motor
14 motor housing element
16 external connector plug
18 motor housing bottom wall
20 plug housing
22 motor stator
24 stator body
26 stator coils
28 motor rotor
30 drive section
32 pump-wheel section
34 rotor support pin
36 separating can
38 mounting flange
40 separating can sidewall
42 separating can bottom wall
44 bottom wall protrusion
46 stator coil connecting elements
48;48' separating-can grounding element
50 connector lug parts
52;52' clamping arrangement
54 radial outside surface
56 connection ring
58;58' clamping elements
60 radial clamping element leg
62 axial clamping element leg
64 separating-can-bottom-wall-sided axial end
66 separating-can-bottom-wall-remote axial end
68 recess
70 separating-can-bottom-wall-remote axial end
72 clamping element opening
74 separating-can-bottom-wall-sided axial end 76 bottom-wall-protrusion-sided lateral clamping element edge
78 bottom-wall-protrusion-remote lateral clamping element edge
D distance vector
L straight line P1,P2 orthogonal projections
R.1,R2 rounding radii
Claims
C L A I M S An automotive electric fluid pump (10) with:
- an electromagnetic motor stator (22),
- a permanent-magnetic motor rotor (28),
- a pot-shaped metallic separating can (36) comprising:
• a cylindrical separating can sidewall (40) which extends through a cylindrical gap between the motor stator (22) and the motor rotor (28), and
• a transverse separating can bottom wall (42) with a bottom wall protrusion (44) which axially protrudes from the separating can bottom wall (42) at a motor-rotor-remote axial side, and
- an electrically conductive separating-can grounding element (48;48') which is configured to electrically connect the separating can (36) with a ground potential, and which comprises a clamping arrangement (52;52') which is in touching contact with a radial outside surface (54) of the bottom wall protrusion (44). The automotive electric fluid pump (10) according to claim 1, wherein the clamping arrangement (52) comprises at least three clamping elements (58) which are distributed along a circumferential direction of the radial outside surface (54) of the bottom wall protrusion (44). The automotive electric fluid pump (10) according to claim 2, wherein the clamping arrangement (52) comprises a connection ring (56) to which all clamping elements (58) are attached. The automotive electric fluid pump (10) according to claim 2 or 3, wherein each clamping element (58) comprises an axial clamping element leg (62) which is shaped such that a separating-can-bottom-wall-sided axial end (64) of the axial clamping
element leg (62) is located more radially outward compared to a separating-can-bottom-wall-remote axial end (66) of the axial clamping element leg (62) if the clamping element (58) is unstressed. The automotive electric fluid pump (10) according to claim 1, wherein the clamping arrangement (52') comprises two clamping elements (58') which are arranged at opposite sides of the bottom wall protrusion (44) in such a way that orthogonal projections (P1,P2) of the two clamping elements (58') onto a straight line (L), which is perpendicular to a distance vector (D) between the two clamping elements (58') and perpendicular to an axial direction of the bottom wall protrusion (44), do not completely overlap. The automotive electric fluid pump (10) according to claim 5, wherein the two clamping elements (58') are provided with a substantially rectangular cross-section in a transverse plane. The automotive electric fluid pump (10) according to claim 5 or 6, wherein a separating-can-bottom-wall-sided axial end (74) of each clamping element (58') is provided with rounded lateral clamping element edges (76,78) in such a way that a rounding radius (R.1) of a bottom-wall-protrusion-sided lateral clamping element edge (76) is larger than a rounding radius (R.2) of a bottom-wall-protrusion-remote lateral clamping element edge (78). The automotive electric fluid pump (10) according to one of the claims 5 to 7, wherein each clamping element (58') is provided with a clamping element opening (72). The automotive electric fluid pump (10) according to one of the preceding claims, comprising an external connector plug (16),
18 wherein the separating-can grounding element (48;48') comprises a connector lug part (50) which is arranged within the external connector plug (16). The automotive electric fluid pump (10) according to one of the preceding claims, wherein the separating-can grounding element (48;48') is a single-piece stamped part. The automotive electric fluid pump (10) according to one of the preceding claims, comprising a plastic motor housing element (14) which defines at least a transverse motor housing bottom wall (18) extending substantially parallel to the separating can bottom wall (42), wherein the separating-can grounding element (48;48') is embedded into the motor housing element (14). The automotive electric fluid pump (10) according to the claims 3 and 11, wherein the connection ring (56) is embedded into the motor housing element (14) and the clamping elements (58) protrude out of the motor housing element (14). The automotive electric fluid pump (10) according to claim 11 or 12, wherein the motor housing bottom wall (18) comprises a recess (68) within which a separating-can-bottom-wall-remote axial end (70) of the bottom wall protrusion (44) is arranged.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/EP2021/077893 WO2023057074A1 (en) | 2021-10-08 | 2021-10-08 | Automotive electric fluid pump |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/EP2021/077893 WO2023057074A1 (en) | 2021-10-08 | 2021-10-08 | Automotive electric fluid pump |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2023057074A1 true WO2023057074A1 (en) | 2023-04-13 |
Family
ID=78179379
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2021/077893 WO2023057074A1 (en) | 2021-10-08 | 2021-10-08 | Automotive electric fluid pump |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2023057074A1 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3726839A1 (en) * | 1986-08-20 | 1988-02-25 | Mabuchi Motor Co | ENGINE |
| US20120014819A1 (en) * | 2010-07-14 | 2012-01-19 | Aisin Seiki Kabushiki Kaisha | Electric pump |
| US20140017073A1 (en) * | 2012-07-16 | 2014-01-16 | Magna Powertrain Of America, Inc. | Submerged rotor electric water pump with structural wetsleeve |
| WO2019101304A1 (en) | 2017-11-22 | 2019-05-31 | Pierburg Pump Technology Gmbh | Vehicle fluid pump |
-
2021
- 2021-10-08 WO PCT/EP2021/077893 patent/WO2023057074A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3726839A1 (en) * | 1986-08-20 | 1988-02-25 | Mabuchi Motor Co | ENGINE |
| US20120014819A1 (en) * | 2010-07-14 | 2012-01-19 | Aisin Seiki Kabushiki Kaisha | Electric pump |
| US20140017073A1 (en) * | 2012-07-16 | 2014-01-16 | Magna Powertrain Of America, Inc. | Submerged rotor electric water pump with structural wetsleeve |
| WO2019101304A1 (en) | 2017-11-22 | 2019-05-31 | Pierburg Pump Technology Gmbh | Vehicle fluid pump |
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