DE102013018317A1 - Electric machine - Google Patents

Abstract

The invention relates to an electric machine (1), in particular an electromotive water pump of a motor vehicle, having a wet space (11) located inside a housing (10) and having a drying space (35) in which an electronic unit (34) is arranged is. In the wet space (11), a rotor (22) and a stator (20) and / or an electromagnet (30), wherein the electronics (34) by means of a at least partially in a recess (42) of the housing (10) einliegen Plug contact (40) with the electromagnet (30) is electrically connected. Here is a free end (48) of the plug contact (35) in the wet room (11) and the other free end (38) in the drying room (35), wherein the plug contact (40) is movably mounted in the recess (42). Furthermore, the invention relates to an arrangement of a plug contact (40).

Description

The invention relates to an electrical machine with a wet room and with a drying room. By electrical machine is meant in particular an electric motor and in particular an electromotive water pump, which is suitably used within a motor vehicle.

Water pumps can basically be categorized into so-called secondary flow pumps and mainstream pumps. A main flow pump is primarily used for cooling the internal combustion engine of a motor vehicle. Conventional water pumps are typically powered by the V-belt of the internal combustion engine. Such water pumps are therefore directly coupled to the engine speed of the engine, which may result in certain operating situations of the vehicle to an unbalanced cooling of the engine. So a sufficient volume flow must be ensured both in the idle engine with hot engine, as well as at maximum speed. This leads at high speed to unwanted turbulence and power losses through the mechanical pump.

Also, electromotive water pumps for the cooling circuit of an internal combustion engine are already known, the drive is controlled electrically or electronically by means of an electric motor which drives a impeller, which is arranged for example in a spiral channel of a pump housing. Such electromotive water pumps can be used in many areas of the engine compartment and of the engine speed virtually independently (electronically) controllable, which also basically a V-belt can be omitted, which in turn can lead to an approximately 10% CO2 savings.

For example, from the EP 1 850 010 B1 an electromotive water pump with integrated electric motor known that drives a pump. The known water pump comprises a separating pot held between a pump cover part and a motor housing part for separating a wet space in which the rotor is arranged and a drying space in which the stator carrying the motor, coil or field windings of the electric motor designed as a brushless DC motor is arranged is.

The invention has for its object to provide a particularly suitable electric machine with a wet room and with a drying room, which suitably has a high efficiency, in particular has an effective sealing of the drying room from the wet room, and which is advantageously inexpensive to produce. Another object of the invention is to provide a particularly suitable arrangement of an electrical plug-in contact, which ensures in particular a seal between a drying room and a wet room.

According to the invention the object is achieved with respect to the electrical machine both by the features of claim 1 and independently thereof by the features of claim 4, and with respect to the arrangement by the features of claim 10. Advantageous developments and refinements are the subject of the dependent claims.

The electric machine has a rotor, a stator and a housing. Within the housing there is a wet room, where wet room is understood to be a room in which at least one liquid is present. Advantageously, the wet space is completely formed by the interior of the housing. In other words, the wet space is limited by the housing. Here, advantageously, the housing is substantially completely filled with a liquid, so that no gaseous substances are present within the housing. Alternatively, the wet space is only in a certain area of the housing.

Within the wet space, both the rotor and the stator is arranged. In this way, these two components are relatively effectively cooled by the liquid, and damage to the electrical machine due to overheating is avoided. Also, the reliability is increased, since both the stator and the rotor are designed for safe operation in contact with the liquid, and thus short circuits due to the liquid do not occur. In addition, it is possible to choose a comparatively small magnetic distance between the rotor and the stator, which increases the efficiency of the electric machine.

The electric machine further comprises a drying room in which an electronics is arranged. The drying space is advantageously outside the housing and in particular adjacent to this. For example, the drying space is arranged within a further housing in order to protect the electronics from environmental influences. By means of the electronics, either the rotor or the stator is preferably energized. Due to the positioning of the electronics in the drying room a formation of short circuits is excluded because of the existing liquid in the wet room, which leads to increased reliability. For example, the drying room is free of any liquid. Alternatively, there is another liquid in the drying room or the drying room is with this further liquid filled, wherein the further liquid is electrically insulating, and thus does not affect the electrical properties of the electronics. The further liquid is z. As an oil, by means of which the electronics is cooled.

By electrical machine is meant in particular an electric motor, and in particular an electromotive water pump. The electric motor or the electromotive water pump is suitably used within a motor vehicle and is in particular a part of this. The electrical operating voltage here is preferably between 12 V and 48 V or equal to these values. In particular, the electromotive water pump is a mainstream pump and serves primarily for cooling an internal combustion engine of the motor vehicle. The power of the electromotive water pump is preferably between 400 W and 1.2 kW. The housing of the electromotive water pump preferably has a cover with a suction and a discharge nozzle. In operation, for example, there is a pressure difference between them of 0.5 bar to 2.5 bar. In a preferred embodiment, the pressure on the side of the pressure port is substantially equal to 2.5 bar. Furthermore, the electromotive water pump comprises an impeller, which is in operative connection with the rotor, which is rotatably mounted about a rotationally fixed motor axis. The stator preferably has a number of electromagnets, which are energized by means of the electronics, which takes place in the manner of an electronically commutating direct current motor. If the electric machine is an electromotive water pump, the liquid in the wet space is the (cooling) liquid to be pumped, which is based in particular on water or water.

Preferably, the area between the stator and the rotor is free of a split tube. In particular, this area is empty, with the exception of the liquid present in the wet space, so that the magnetic field lines propagating between the rotor and the stator are not affected. This region is particularly preferably comparatively small, ie the distance between the rotor and the stator comparatively low, which increases the efficiency of the electric machine. In this way, it is possible to reduce the overall height of the electric machine with the same power, so the expansion in the axial direction, or to reduce the diameter of the electric machine.

Furthermore, eliminates the cost of materials of the can and any seals, which contributes to a cost reduction in the production. The reliability of the electrical machine is increased because a detachment of the can or displacement of the can due to a vibration of the electric machine is avoided. Otherwise, this would lead to a friction between the rotor and the can, which on the one hand causes an increased thermal load due to the friction and a reduction in the efficiency of the electric machine.

Suitably, the electric machine comprises a, in particular made of brass, plug contact, which rests in a recess introduced into the housing. In particular, a positioning of at least part of the plug-in contact within the recess is understood. The cross section of the recess is for example round, so that the recess is designed in the manner of a bore, or adapted to the cross section of the plug-in contact. By means of the plug contact, in particular via the plug contact, the electronics with the rotor or the stator is electrically connected, for. B. with the component having an electromagnet or at least one electrical coil. One free end of the plug contact is located in the wet room and the other in the dry room. Appropriately, at least one of the free ends of the plug contact a cable or a stranded tailed, for example, welded, soldered or plugged.

For example, the plug contact is firmly connected to the housing, for. B. a casting material is arranged in the recess, the plug contact thus shed in the region of the housing with this. In this way, a comparatively secure sealing of the drying room is realized by the wet room. Alternatively, the plug contact is movably mounted in the recess. In this way, the electrical connections, which are made by means of the plug contact, loaded comparatively low in vibration of the housing, and the reliability of the electrical machine is increased. Furthermore, an assembly of the electric machine is facilitated in a tolerance compensation due to the mobility of the plug contact. Due to the mobility of the plug-in contact, any seals around the plug-in contact may be tension-free and suitably positioned around the plug contact, in particular concentric with the plug contact, which improves a seal between the wet and the dry space. Conveniently, the electrical machine has a number of plug contacts, in particular three plug contacts.

An alternative solution, which can also take place in combination, provides that the electric machine, which in turn is in particular an electric motor and in particular an electromotive water pump of a motor vehicle, has a wet room and a drying room. The wet room is inside a case. In particular, the wet space is determined by the housing. In other words, the wet room completely fills the housing. Within the wet room is a liquid, such as (cooling) water, and the wet room is z. B. completely filled with the liquid. In the wet room an electromagnet is arranged, thus the electromagnet is inside the housing.

In the drying room, which is located in particular outside the housing and advantageously adjacent to this, an electronics is arranged. The electronics is electrically connected to the electromagnet by means of a plug contact, which is preferably made of brass. The plug contact is located in a recess which is introduced into the housing. In other words, the plug contact is at least partially disposed within the recess. Here is a free end of the plug in the wet room, namely the free end, which is electrically contacted with the electromagnet, and the other free end is located in the drying room, said free end is electrically connected to the electronics. The electrical connection is in this case preferably by means of a cable or a strand, which is in particular welded, soldered or plugged at the respective free end. Preferably, a copper wire is welded to the part of the plug contact located in the wet area and / or the electronics is plugged onto the part of the plug contact located in the dry room or soldered to it. Thus, more cables can be omitted.

The plug contact is movably mounted in the recess. Consequently, a tolerance movement of the plug contact within the recess is made possible. In this way, the electrical connection between the plug contact and the electronics or the electromagnet is mechanically decoupled from the housing, which leads to a lower load on the connection with vibrations of the housing. The cross section of the recess is expediently round, and thus the recess designed in the manner of a bore. Alternatively or in combination, the cross section of the recess is adapted to the cross section of the plug contact. In particular, the electrical machine has a number of such plug contacts, preferably three. Advantageously, the number of electromagnets is also three or a multiple thereof. If a plurality of plug contacts, in particular three plug contacts, and a plurality of electromagnets are present, an assembly of the electromagnet is simplified, since each plug contact due to the mobility can be independent of the other plug contacts, and thus any surrounding the respective plug contacts seals are charged comparatively low.

The plug contact is movably mounted at least in the axial direction, wherein in the axial direction, in particular the direction of the axis of the rotor is understood. For example, the plug contact is also movably mounted in a direction perpendicular to the axial direction. However, the mobility is particularly preferably given only in the axial direction, which leads to an improved sealing of the dry space of the wet room.

In a suitable embodiment of the invention, the plug contact in the region of the recess is surrounded by an O-ring. In other words, the plug-in contact protrudes through an O-ring and the plug-in contact bears against the housing in particular via the O-ring. In this way, on the one hand, tolerance compensation and, on the other hand, a comparatively effective sealing of the wet space from the drying space is created. The O-ring is z. B. made of a rubber and has a comparatively high elasticity.

In particular, the electric machine has at least one, advantageously two, plastic discs, which likewise surround the plug contact in the region of the recess. The plug contact thus protrudes through the plastic disc, which is in particular a perforated disc made in the manner of a ring. Conveniently, the material of the plastic disc is electrically insulating. If two plastic discs are present, the O-ring is arranged in the direction of the plug contact between the plastic discs, so that there is a sequence of plastic disc, O-ring, plastic disc. The direction of the plug contact designates in particular the direction in which the expansion of the plug contact is maximum. For example, the direction of the plug-in contact is equal to the axial direction of the electric machine. The one or more plastic discs are preferably on the O-ring. By means of the plastic disc or the plastic discs of the O-ring is protected from mechanical stress and is particularly electrically isolated.

Preferably, at least one of the free ends of the plug contact is beveled, which facilitates an introduction into the recess of the housing. In particular, this free end is on the dry side. Suitably, the plug contact is thus introduced from the wet room into the recess during assembly of the electrical machine. Consequently, at an increased pressure in the wet room compared to the drying space of the plug contact is pressed into the recess and thus the drying space from the wet room through the plug contact and the O-ring, if present, sealed comparatively effective.

Conveniently, the free end of the plug contact, which is located in the wet room, at least partially surrounded by a guide sleeve. In other words, the free end is in the guide sleeve. The guide sleeve is in this case preferably rigidly coupled to the electromagnet or the rotor or the stator, and in particular is located between the plug contact and the guide sleeve, a tolerance gap. Thus, the movement of the plug contact is restricted by means of the guide sleeve. Consequently, upon movement of the plug contact relative to the housing and thus also relative to the electromagnet or the stator or the rotor by means of the guide sleeve damaging precisely these components is prevented. Further, the stator, if the guide sleeve coupled thereto or is a part thereof, positioned by means of the guide sleeve relative to the plug contact and thus simplifies mounting of the stator. In particular, three plug contacts and one associated guide sleeve, so a total of three guide sleeves, available, which further simplifies the assembly.

In particular, the stator of the electric machine has the electromagnet and the rotor comprises a permanent magnet. Advantageously, in this case the electronics constructed in the manner of a bridge circuit, z. B. in a B6 circuit. The area between the stator and the rotor is preferably free of a split tube. Preferably, the electric machine has no can. In this way, the area between the rotor and the stator can be made comparatively narrow, so that the efficiency of the electric machine is increased. Conveniently, both the rotor and the stator are in the wet space. In this way, a comparatively efficient cooling of the two components is possible. Also, the electric machine is mechanically stiffer.

The drying space preferably adjoins the housing. Within the drying space are particularly preferred only the electronics and the free end of the plug contact, which is why the drying room can be made relatively small. Alternatively or in combination with this, the drying space on the side facing away from the housing is surrounded by a heat sink, so that the drying space is bounded on the one hand by means of the housing and on the other hand by means of the heat sink. In this way, a comparatively simple sealing of the drying space is made possible. However, at least the electronics on the side facing away from the housing is surrounded by a heat sink and is in thermal contact therewith. In this way, overheating of the electronics is prevented.

To produce the electric machine, the recess is introduced into the housing in a first step, provided that it is not already in it, for example, the housing is already cast with a recess. The housing is made in particular of plastic or aluminum. In a further step, the plug contact, to which the plastic discs or the O-ring are applied, if they are present, introduced into the recess. This is preferably done from the wet room. Alternatively, the plastic slides and the O-ring are first positioned within the recess, which takes place, for example, from the drying room. In a subsequent step, the plug contact is inserted into the recess, the plastic discs and the O-ring. In a further step, the electromagnet or the rotor or the stator is positioned within the wet space and connected to the plug contact. In a further step, the electronics is electrically contacted with the free end located inside the dry space, the free end which has been passed through the cutout.

The arrangement comprises a plug contact, a wet and a dry room. These elements are preferably part of an electrical machine, in particular an electric motor. One of the free ends of the plug-in contact is located in the wet room and the other of the free ends of the plug-in contact is located in the dry room. The plug contact is movably mounted. Consequently, a movement of the free ends within the respective rooms is possible. This simplifies production of the electrical connection with the plug contact during assembly.

Embodiments of the invention will be explained in more detail with reference to a drawing. Show:

1 a perspective view of an electromotive water pump connected via a housing flange with a motor housing part pump cover of a pump housing,

2 a further embodiment of the water pump in a sectional view, and

3 a section from 2 ,

Corresponding parts are provided with the same reference numerals in all figures.

The 1 and 2 each show an electric motor driven water pump 1 with a pump cover 2 , which differ between the two examples, and with a motor housing part 4 , which have a cover flange 6 and a housing flange 8th to a housing 10 , which consists of aluminum and / or stainless steel, are bolted together. Through the housing 10 is a wet room 11 educated. The pump cover 2 has an axial inlet nozzle 12 as well as an axially oriented drain or discharge nozzle 14 on. When working on the centrifugal or Radialpumpenprinzip water pump 1 the fluid (water) passes through the suction port 12 in the wet room 11 and is by means of an electric motor driven impeller 16 on a spiral path radial, ie perpendicular to a motor axis 18 transported to the outside and passes over the discharge nozzle 14 from the water pump 1 out.

How out 2 is apparent, is within the motor housing part 4 , and thus within the wet room 11 , an electrically or electronically commutated electric motor with a stator 20 and with one around the fixed motor axis 18 rotating rotor 22 arranged. The one number of permanent magnets 23 having rotor 22 is with the impeller 16 positively coupled and around the fixed motor axis 18 in a cover-side slide bearing 24 as well as in a cup bottom side slide bearing 26 axially stored. In the radial direction are located between the rotor 22 and the stator 20 which comprises a number of coils, each having an electromagnet 30 form, no further elements.

Rather, it flows during operation of the pump 1 the pumped medium between the stator 20 and the rotor 22 and thus cools them. Furthermore, the rotor 22 and / or the stator 20 other openings, not shown, through which the fluid flows, and thus cools. Likewise, a passage of the pumped medium between the motor axis 18 and the rotor 20 possible.

On the pump cover 2 opposite side of the motor housing part 4 is a cup-shaped heat sink 32 on the motor housing part 4 tethered, within which an electronics 34 is arranged. The pot bottom of the housing 10 and the heat sink 32 limit a drying room 35 , which is free of the pumped medium. The Electronic 34 is on the pot bottom of the heat sink 32 attached and is in thermal contact with this. The Electronic 34 is constructed as a B6 circuit and has a stranded wire 36 on, at a free end 38 a plug contact 40 made of brass is soldered. Inside the drying room 35 Thus, only the electronics are located 34 and the free 38 in the axial direction, ie parallel to the motor axis 18 extending plug contact 40 ,

As in 3 shown is the plug contact 40 partially within a recess 42 Arranged in the bottom of the motor housing part 4 is introduced. In the recess 42 are still two annular plastic discs 44 and an O-ring 46 which is made of a rubber. The plastic discs 44 and the O-ring 46 surround the plug contact 40 , where the plastic discs 44 turn the O-ring 46 surrounded in the axial direction. By means of the O-ring 46 on the one hand the wet room 11 from the drying room 35 sealed. On the other hand, due to the elasticity of the material of the O-ring 46 a movement of the plug contact 40 in the axial direction even after installation to a limited extent possible. The plastic discs 44 in turn protect the O-ring 46 before mechanical damage.

About two thirds of the plug contact 40 are located inside the wet room 11 , this section of the plug contact 40 is electrically isolated to avoid a short circuit. That in the wet room 11 Free-standing 48 is from a guide sleeve 50 surrounded, which is part of the stator 20 is. Consequently, the guide sleeve 50 mechanically rigid with the housing 10 coupled. The guide sleeve 50 is made of a plastic and between the guide sleeve 50 and the plug contact 40 is a tolerance gap 52 , which is a movement of the plug contact 40 relative to the guide sleeve 50 and thus to the stator 20 allows. In the area between the guide sleeve 50 and the recess 42 is a strand 54 at the plug contact 40 soldered, and the stranded wire 54 thus in electrical contact with the plug contact 40 , This is the insulation of the plug contact 40 removed there. The strand 54 is part of one of the electromagnets 30 , By means of the plug contact 40 is thus an electrical connection between one of the electromagnets 30 and the electronics 34 created. The water pump 1 has three such plug contacts 40 and the respective associated recesses 42 , Plastic discs 44 and o-rings 46 on, with each of the plug contacts 40 each with two electromagnets 30 electrically contacted.

For mounting the water pump 1 First, the plastic discs 44 and o-rings 46 from the drying room 35 in the recesses 42 introduced and positioned there. In a further step, the plug contacts 40 in the respective recess 42 from the wet room 11 forth in the respective recess 42 introduced. The arrangement of the plug contacts 40 takes place here independently, which simplifies the installation. In further steps, the strands 36 . 54 at the respective associated plug contact 40 attached and the stator 20 in the motor housing part 4 positioned.

In summary, the invention relates to an electrical machine 1 , in particular electromotive water pump of a motor vehicle, with a wet room 11 that is inside a case 10 located, and with a drying room 35 in which one electronics 34 is arranged. In the wet room 11 is a rotor 22 and a stator 20 arranged and / or an electromagnet 30 , where the electronics 34 by means of an at least partially in a recess 42 of the housing 10 inserted plug contact 40 with the electromagnet 30 electrically connected. Here is a free end 48 of the plug-in contact 35 in the wet room 11 and the other free 38 in the drying room 35 , where the plug contact 40 movable in the recess 42 is stored. Furthermore, the invention relates to an arrangement of a plug-in contact 40 ,

The invention is not limited to the embodiments described above. Rather, other variants of the invention can be derived therefrom by the person skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the exemplary embodiments can also be combined with one another in other ways, without departing from the subject matter of the invention.

LIST OF REFERENCE NUMBERS

1

water pump

2

pump cover

4

Motor housing part

6

cover flange

8th

housing flange

10

casing

11

wet room

12

inlet connection

14

Drain / discharge nozzle

16

impeller

18

motor axis

20

stator

22

rotor

23

permanent magnet

24

Cover-side slide bearing

26

cup bottom side plain bearing

30

electromagnet

32

heatsink

34

electronics

35

drying room

36

braid

38

free end

40

plug contact

42

recess

44

Plastic disc

46

O-ring

48

free end

50

guide sleeve

52

tolerance gap

54

braid

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1850010 B1 [0004]

Claims (10)

Electric machine ( 1 ), in particular electromotive water pump of a motor vehicle, with a rotor ( 22 ) and with a stator ( 20 ) in a wet room ( 11 ) located inside a housing ( 10 ) are arranged, and with a drying room ( 35 ), in which an electronics ( 34 ) is arranged. Electric machine ( 1 ) according to claim 1, characterized in that the area between the stator ( 20 ) and the rotor ( 22 ) is free from a canned. Electric machine ( 1 ) according to claim 1 or 2, characterized by one in a recess ( 42 ) of the housing ( 10 ) inserted plug contact ( 40 ), with the electronics ( 34 ) and the rotor ( 22 ) or the stator ( 20 ) is electrically connected, wherein a free end ( 48 ) of the plug contact ( 40 ) in the wet room ( 11 ) and the other free ( 38 ) in the drying room ( 35 ) and wherein the plug contact ( 40 ) in particular movable in the recess ( 42 ) is stored. Electric machine ( 1 ), in particular electromotive water pump of a motor vehicle, with a wet space ( 11 ) located inside a housing ( 10 ) and in which an electromagnet ( 30 ), and with a drying room ( 35 ), in which an electronics ( 34 ), the electronics ( 34 ) by means of an at least partially in a recess ( 42 ) of the housing ( 10 ) inserted plug contact ( 40 ) with the electromagnet ( 30 ), in particular the stator ( 20 ), wherein a free end ( 48 ) of the plug contact ( 35 ) in the wet room ( 11 ) and the other free ( 38 ) in the drying room ( 35 ) and wherein the plug contact ( 40 ) movable in the recess ( 42 ) is stored. Electric machine ( 1 ) according to claim 3 or 4, characterized in that the plug contact ( 40 ) Is mounted movably at least in the axial direction. Electric machine ( 1 ) according to one of claims 3 to 5, characterized in that the plug contact ( 40 ) in the region of the recess ( 42 ) of an O-ring ( 46 ) is surrounded, wherein the plug contact ( 40 ) in the region of the recess ( 42 ) in particular of two plastic discs ( 44 ), wherein the O-ring ( 46 ) in the direction of the plug contact ( 40 ) between the plastic discs ( 44 ) is located. Electric machine ( 1 ) according to one of claims 3 to 6, characterized in that one of the free ends ( 38 ) of the plug contact ( 40 ), in particular that on the dry side ( 35 ), and / or that in the wet room ( 11 ) Free ( 48 ) of the plug contact ( 40 ) in a guide sleeve ( 50 ) is present. Electric machine ( 1 ) according to one of the preceding claims, characterized by a the electromagnet ( 30 ) having stator ( 20 ) and a permanent magnet ( 23 ) having rotor ( 22 ), the area between the stator ( 20 ) and the rotor ( 22 ) is free of a split tube, and / or wherein the rotor ( 22 ) and the stator ( 20 ) in the wet room ( 11 ) are arranged. Electric machine ( 1 ) according to one of the preceding claims, characterized in that only one of the free ends ( 38 ) of the plug contact ( 40 ) and the electronics ( 34 ) in the drying room ( 35 ) and / or that the electronics ( 34 ) on the housing ( 10 ) facing away from a heat sink ( 32 ), in particular the drying room ( 35 ) limited Arrangement with an electrical plug contact ( 40 ), with a wet and a dry room ( 11 . 35 ), in particular an electrical machine ( 1 ), whereby a free ( 48 ) of the plug contact ( 40 ) in the wet room ( 11 ) and the other free ( 38 ) in the drying room ( 35 ) and wherein the plug contact ( 40 ) is movably mounted.

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