Liquid-cooled, electronically commutated electric motor

Abstract

The invention relates to an electronically commutated electric motor comprising a liquid-cooled stator having iron-free hollow cylindrical stator windings and a coolant circuit for conducting coolant through the electric motor, a rotor rotatably arranged concentrically with the stator, a motor housing accommodating the stator and the rotor, a connection assembly and at least one electrical connection wire for electrically contacting the stator windings. The invention also relates to a connection assembly for such an electronically commutated electric motor. The connection assembly has a closing cover, at least one plug-in connection means for establishing electrical contact between the stator windings and the electrical connection wires and a sealing element between the plug-in connection means and a housing of the connection assembly, the connection assembly realizing a liquid-tight sealing of the motor housing.

Description

[Technical field]

[0001] The present invention relates to an electronically commutated electric motor having a coolant circuit for passing a coolant through the electric motor and a liquid-cooled stator having iron-free, hollow, cylindrical stator windings, a rotor rotatably arranged concentrically with the stator, a motor housing containing the stator and rotor, a termination assembly, and at least one electrical connection cable for electrically contacting the stator windings. In a further aspect, the present invention relates to a connection assembly for such an electronically commutated electric motor.

[0002] Electric motors with liquid-cooled stators are known in the art and are used in various applications where sufficient cooling of the waste heat generated by the power losses of the electric motor is not guaranteed. Such liquid-cooled electric motors are used in aviation, automotive engineering and air conditioning technology, as well as in aerospace, raw material extraction and power plant technology.

[0003] A typical liquid-cooled electric motor is known, for example, from US Pat. No. 6,489,697. This electric motor has a hollow cylindrical stator winding surrounded by a soft magnetic reverse circuit connection and a rotor arranged concentrically with the stator so that it can rotate. The stator winding and the rotor with the reverse circuit connection are accommodated in a motor housing provided with closing covers on both sides. An oil circuit is provided to dissipate heat losses occurring in the stator winding and the reverse circuit connection, the cooling medium first flows axially through the inner circumference of the stator winding and then through the outer circumference of the reverse circuit connection. Between the stator winding and the rotor a ceramic sleeve is provided, which defines both a rotation gap to the rotor and a hollow cylindrical flow path for the coolant between the ceramic sleeve and the stator winding. However, the design of this liquid-cooled electric motor is relatively complex and therefore expensive to manufacture and prone to failures during operation. Due to the active cooling system, this electric motor must be inspected at regular intervals.

[0004] There are also electric motors that are sealed for use in extreme environmental conditions. The application areas of such sealed electric motors range from automotive applications to medical technology. For example, DE 38 04 677 A1 describes such an electric motor with a watertight seal of the cable feed-through between the housing edge and the closing cover, in which the connecting pins provided on the outside of the housing for the plug contacts are connected to the cable core with the electrical connecting cable and the stator winding via a circuit board in the closing cover. US 10 389 202 A1 also shows a sealed electric motor in which the connecting pins protruding outside the motor housing are connected to the stator winding via a printed circuit board embedded in the closing cover. In addition to the connecting pins and the circuit board, the motor control unit is also embedded in the closing cover of the motor housing. The latter two documents do not show an electric motor in which a coolant flows through the motor.

[0005] SUMMARY OF THE DISCLOSURE The object of the present invention is to improve electronically commutated electric motors of the type mentioned above with regard to ease of assembly, problem-free operation and simple construction.

[0006] This problem is solved in that the connection assembly is composed of a closing cover and at least one plug-in connection means for electrically contacting the electric connection cable with a corresponding plug-in connection part of the stator winding of the stator, the connection assembly providing a liquid-tight sealing of the motor housing, a sealing element being provided between the housing of the connection assembly and the plug-in connection means. Such a connection of the stator winding of such a hollow cylindrical stator, preferably with a slotless stator winding, makes it possible to seal the motor housing against liquid leakage, in particular against the coolant of the coolant circuit. Furthermore, the liquid-tight connection of the connection assembly with the motor housing prevents substances surrounding the electric motor, such as liquids or gases, from reaching the electric contacts of the motor housing or from entering the motor housing and damaging the electric motor. Furthermore, a simple electrical contact of the stator winding to the electric connection cable is possible by means of an electrical plug connection. The connection assembly, configured as a closing cover for closing the open front face of the motor housing, is configured as a separate component that is provided during the assembly of the electric motor and is firmly connected to the motor housing, for example by means of a screw connection or a clip connection. In one variant, the connection assembly can also be configured to be removable and replaceable as required. In the electric motor according to the invention, the electrical contact between the stator windings of the stator and the electrical connection cable is made in the connection assembly or in the motor housing and is sealed from the environment by the connection assembly. Thus, the electrical contact between the plug-in connection means and the electrical connection cable leading to the connection assembly is further designed in the connection assembly. The electrical contact between the electrical connection cable and the stator winding is made in the connection assembly by the plug-in connection means connected to the electrical connection cable and the plug-in connection parts connected to the stator winding.

[0007] The stator winding is preferably formed by several individual coils, particularly preferably 12 individual coils. The individual coils are preferably connected by star or delta connections to form a three-phase winding system with three stator winding phases. Each winding phase preferably consists of four individual coils.

[0008] In a particularly preferred embodiment, the stator has a stator winding with three stator winding phases and three plug-in connection means each connected to one stator winding phase and arranged on a first side of the motor housing, and the connection assembly has three plug-in connection means each connected to an electrical connection cable. Preferably, the individual stator winding phases are formed by several individual coils, particularly preferably four individual coils. The individual coils are preferably connected by star or delta connection to form a three-phase winding system. In a three-phase winding system, it is possible to start or stop the rotor from or in any stop position, while at the same time the wiring effort of the three phases is relatively low.

[0009] In a preferred embodiment, the rotor comprises at least one permanent magnet or several permanent magnet segments distributed around the circumference. The rotor is preferably designed with two, four or six poles. Preferably, the permanent magnets distributed around the circumference are arranged in a Halbach array, with several permanent magnet segments, in particular two permanent magnet segments, forming a magnetic pole. Such a multi-pole design of the permanent magnet arrangement allows particularly high torques to be generated.

[0010] In a preferred embodiment for mounting the connection assembly on the motor housing, the plug-in connection means connected to the electric connection cable are connected to corresponding plug-in connection parts of the stator winding by sliding the stator winding while the connection assembly is mounted on the motor housing. In addition to being very easy to mount, it also allows the use of a different connection assembly without replacing or adapting the stator and the rotor rotatably arranged within the inner circumference of the stator.

[0011] In a simple variant, the plug-in connection means of the connection assembly can be configured as a plug socket, and the corresponding plug-in connection parts of the stator winding are preferably configured as connection pins. Such a plug socket allows a simple, removable plug-in connection for bringing the electrical connection cable into electrical contact with the stator winding. The plug socket and the complementary plug-in connection parts, e.g. the connection pins, are connected directly to the stator windings of the stator, thus allowing the power supply of the stator windings by a simple plug connection between the connection assembly and the motor housing.

[0012] Advantageously, an O-ring can be provided as a sealing element between the housing of the connection assembly and the plug socket. Due to the very high requirements regarding the tightness of the connection assembly with respect to the electric connection cable, in addition to the inherent sealing effect of the electric connection cable embedded in the connection assembly and the embedded plug socket, an O-ring can be arranged as a sealing element in the gap between the plug socket and the housing of the connection assembly.

[0013] In a suitable embodiment, a radial seal is provided between the connection assembly and the motor housing. The radial seal allows reliable sealing of the interface between the motor housing and the connection assembly, so that high sealing requirements can be met both from the outside to the inside and from the inside to the outside. Optionally, in addition to the radial seal, a supplementary axial seal, for example a flange seal, can be provided between the connection assembly and the motor housing to improve the tightness against leakage of coolant from the cooling circuit and the durability of the seal between the connection assembly and the motor housing.

[0014] According to a further embodiment, a cable assembly is provided, which comprises an electrical connection cable, a plug-in connection means and at least one busbar for electrically connecting the electrical connection cable to the plug-in connection means. Such a prefabricated cable assembly further facilitates the production of the connection assembly, in particular in the case of injection molding or mould casting of the connection assembly, and ensures a good sealing of the electrical contact between the electrical connection cable or busbar and the housing of the connection assembly. The connection between the busbar and the plug-in connection means is preferably made by pressing, welding or soldering. On the other hand, the electrical connection cable is connected to the busbar, in particular by welding or soldering. Depending on the number of stator winding phases of the stator, the cable assembly can have several electrical connection cables, busbars and plug-in connection means, which are combined into a common cable assembly for time-saving further processing. During the manufacturing process of the connection assembly, the cable assembly is held in a defined position in a molding tool so that when the connection assembly is later mounted to the open front or first side of the motor housing, the positions of the plug-in connection means exactly match the positions of the plug-in connection parts located on the motor housing and connected to the stator winding phases of the stator.

[0015] Preferably, the cable assembly may have three electrical connection cables, three sockets, and three bus bars, and the three electrical connection cables, three sockets, and three bus bars are mechanically connected to each other. By combining several connection parts into a common cable assembly, it is easy to handle the common cable assembly when manufacturing the connection assembly.

[0016] In a practical embodiment, the connection assembly is made of thermoplastic or thermosetting resin by injection molding or mold casting, and a connection electronic circuit with plug-in connection means and an electrical connection cable is embedded in the connection assembly. The connection electronic circuit allows simple electrical contact of the individual stator winding phases to the power supply, and this electrical interface is injection molded or otherwise sealed in the connection assembly. The connection electronic circuit can be configured in the form of an assembled circuit board with all the necessary components and connection cables.

[0017] In a further variant, a commutation electronic circuit for commutating the electric motor is provided, which is also embedded in the connection assembly. This makes it unnecessary to provide and arrange the commutation electronic circuit separately on the motor housing. The commutation electronic circuit can in particular be configured as a printed circuit board with all necessary elements, electronic components and cables, and can optionally be combined with the connection electronic circuit. Furthermore, the commutation electronic circuit can also have an integrated sensor, preferably an angular position sensor sensitive to the magnetic field, which in particular detects the magnetic field of a diametral control magnet attached at the end of the rotor shaft. Such an integrated position sensor allows for a simple control of the electronically commutated electric motor.

[0018] In a particular embodiment, the connecting electronic circuit and / or the rectifying electronic circuit are provided with an additional layer of thermoplastic or thermosetting resin, which is applied in an upstream first step by injection molding, transfer molding or mold casting. As a result, the sensitive electric and electronic components undergo double overmolding and / or sealing in a two-stage process and are thus specially protected. Thus, when producing a connection assembly, the connecting electronic circuit and / or the rectifying electronic circuit are overmolded on all sides in a first processing step, preferably together with all circuit boards, elements and cables with a defined material thickness of thermoplastic resin. For hermetic sealing, these already sealed components are embedded a second time in a thermoplastic or thermosetting resin in a second processing step, which further ensures that possible holding positions from the first processing step are sealed. In addition to sealing the components, in this second processing step the housing shape of the connection assembly with an integrated closing cover is also configured.

[0019] In a preferred embodiment, the coolant circuit for passing coolant through the electric motor further comprises a first coolant channel between the motor housing and the outer periphery of the stator, a second coolant channel between the inner periphery of the stator and the rotor, and a coolant redirection for fluidly connecting the first and second coolant channels, the coolant redirection being preferably at least partially constituted by the connection assembly. In the electric motor according to the invention, oil or special heat transfer fluids, preferably with a boiling point above 200°C, are used in particular as coolant. Effective cooling of the electric motor is achieved by passing such a coolant through the coolant circuit. In the gap between the outer wall of the motor housing and the outer periphery of the stator, the coolant absorbs the corresponding magnetic and eddy current losses of the back-circuit material. Resistive and eddy current losses in the stator windings are dissipated when the coolant flows through the rotation gap between the inner periphery of the stator and the rotor. This means that the two heat generating components, the stator windings and the back-circuit, are in direct contact with the coolant, thus allowing optimal heat dissipation. The coolant circuit preferably allows a flow rate of 2-7 liters per minute. The coolant is passed through the coolant circuit with a pressure of 1-10 bar, preferably 3-5 bar. The thermal power losses of electric motors of 3 kW, 5 kW and above can be dissipated by the coolant.

[0020] In a reasonable design, the second coolant channel between the inner circumference of the stator and the rotor has a smaller cross-sectional area than the first coolant channel between the motor housing and the outer circumference of the stator. Since most of the power losses, and therefore heat generation, occur in the stator windings when the electric motor is under high load, a smaller cross-section in the rotation gap between the stator windings and the rotor allows a better heat transfer by turbulent coolant flow and a lower thermal load on the electric motor. Moreover, a large air gap between the stator and the rotor does not allow high torque to be generated, or a small air gap is required to generate high torque.

[0021] In a modification of the connection assembly, the coolant redirectors can be configured as holes or openings in the connection assembly, which allow for a deflection of the coolant in the coolant circuit toward a target, avoiding stop zones and deposits in the coolant circuit. Thus, the coolant redirectors configured in the connection assembly for the fluid connection of the first and second coolant channels can contribute to improving the heat transfer.

[0022] In a practical variant, the coolant circuit has a coolant inlet to a first coolant channel arranged on the circumference of the motor housing and a coolant outlet from a preferably second coolant channel, the coolant outlet being arranged on the second side of the motor housing opposite the connection assembly. The coolant flows directly into the gap between the motor housing and the outer circumference of the stator through the coolant inlet on the motor housing, which can be configured, for example, as holes distributed around the circumference, and then flows through a coolant redirection section and the second coolant channel to an outlet provided on the second side of the motor housing, which can be configured as a hole. As a result, the output side ball bearing of the motor shaft may be cooled and lubricated by the oil used as coolant.

[0023] In an alternative embodiment, the coolant inlet and outlet may be designed inverted, so that the coolant inlet is provided on the second side of the motor housing and the coolant outlet is provided on the circumference of the motor housing, in which the coolant flows from the alternative coolant inlet on the second side of the motor housing first through the second coolant channel and then through the first coolant channel via a coolant redirector towards the alternative coolant outlet on the circumference of the motor housing.

[0024] In a further preferred embodiment, the connection assembly provides a liquid-tight seal between the electrical contacts of the plug-in connection means of the electrical connection cable and corresponding plug-in connection parts of the stator windings of the stator and the coolant circuit of the electric motor.

[0025] Furthermore, the invention relates to a connection assembly for an electronically commutated electric motor according to one of the aforementioned embodiments, the connection assembly having at least one electrical connection cable and a closing cover of the electronically commutated electric motor, at least one plug-in connection means for electrically contacting the stator winding with the electrical connection cable, and a sealing element between the housing of the connection assembly and the plug-in connection means. In conjunction with the motor housing of the electric motor, this connection assembly allows a liquid-tight seal of the corresponding side of the motor housing as well as an electrical contact of the stator winding by the plug-in connection means. The connection assembly thus forms an interface sealed against fluid exchange as well as an electrical interface for the power supply of the electric motor.

[0026] In a particularly preferred application, electronically commutated electric motors having liquid-cooled stators can be used in the extraction of raw materials, particularly crude oil and natural gas. [Brief description of the drawings]

[0027] In the following, non-limiting embodiments of the invention will be explained in more detail with reference to the following exemplary drawings: [Figure 1] 1 is a partial cutaway side view of an electronically commutated electric motor according to the present invention; [Diagram 2] FIG. 2 is a cross-sectional view of the electric motor of FIG. [Diagram 3] FIG. 2 is an exploded perspective view of the electric motor of FIG. 1. [Figure 4] FIG. 2 is an enlarged cutaway view of a connection assembly of the electric motor of FIG. 1. [Diagram 5] FIG. 2 is a perspective view of a pre-assembled cable assembly for the connection assembly of the electric motor according to the invention of FIG. 1;

[0028] The electronically commutated electric motor 1 according to the invention, shown in figures 1 and 2, is designed as an internal rotor and is liquid-cooled. The electric motor 1 comprises a rotor 2, which is aligned concentrically with a hollow cylindrical stator 3 and rotatably arranged within the stator 3. The rotor 2 is shown uncut both in the partially cutaway side view of the electric motor 1 in figure 1 and in the associated cross-sectional view in figure 2. The rotor 2 comprises at least one permanent magnet or several permanent magnet segments distributed around the circumference. In addition to the stator 3 and the rotor 2, all other components of the electric motor 1 according to the invention can also be accommodated or arranged in a cylindrically constructed motor housing 4, preferably made of steel. A first side of the motor housing 4 is closed liquid-tight by a connection assembly 5. The connection assembly 5 is used for the electrical contacts of the electric motor 1. The essentially gas-tight sealing of the motor housing 4 by the connection assembly 5 prevents both the leakage of coolant from the interior of the electric motor 1 and the penetration of undesired media into the electric motor 1. The opposite side of the connection assembly 5 is the second or output side of the motor housing 4. The motor housing 4 is cup-shaped and can be designed in one piece, the bottom of the cup representing the second side of the motor housing and the open end of the cup representing the first side of the motor housing. The first open end of the motor housing 4 can be closed in a liquid-tight manner by a connection assembly 5. The one-piece motor housing 4 consisting of a cylindrical motor housing and a second side of the motor housing has the advantage that there is no transition connection between the two parts through which the coolant could escape from the interior of the electric motor 1 or through which undesirable media could penetrate into the electric motor 1. The one-piece motor housing 4 can also be manufactured more cost-effectively, since no additional work steps are required to connect the cylindrical part of the motor housing in a liquid-tight manner to the second side of the motor housing.

[0029] The liquid-cooled stator 3 of the electric motor 1 according to the invention consists of an iron-free, hollow-cylindrical, self-supporting stator winding 6, divided into several individual coils, and an externally arranged soft magnetic reverse circuit connection 7. The external reverse circuit connection 7 consists of a laminated core, also having a hollow-cylindrical design, and surrounds the stator winding 6, with which the reverse circuit connection 7 is in firm contact. The hollow-cylindrical stator winding 6 can be wound with baked-enamel wire, which is heated during manufacture and, when hardened, holds the stator winding 6 together in a dimensionally stable manner at low temperatures. Furthermore, a hollow-cylindrical ceramic support sleeve may be provided, which is arranged concentrically inside the stator winding 6 for use at high temperatures. Such a ceramic support sleeve ensures the necessary air gap between the rotor 2 and the stator 3 even at high operating temperatures. The stator winding 6 can also be further coated with a potting compound, which increases the stability of the stator winding 6, especially at high operating temperatures, and completely seals the stator winding 6.

[0030] A rotor shaft 8, which extends coaxially through the rotor 2 or is attached to it as a stub shaft, is mounted both in a rolling bearing 9 arranged on the second side of the motor housing 4 and in an opposing second rolling bearing 10 accommodated in a front flange 25 in the region of the first side of the motor housing 4. The part of the rotor shaft protruding from the motor housing 4 can have connecting toothing.

[0031] The electronically commutated electric motor 1 according to the invention further comprises a coolant circuit 12 having a coolant inlet 13 provided on the periphery of the motor housing 4 and constituted by a number of holes arranged facing the motor housing 4 in a peripheral recess, a first coolant channel 14 extending in an annular manner between the motor housing 4 and the outer periphery of the stator, a coolant redirection 15 constituted between a front flange 25 and an associated surface of the connection assembly 5 and preferably having several holes or openings in the front flange 25, a second coolant channel 16 extending in an annular manner between the inner periphery of the stator 3 and the rotor 2, and a coolant outlet 17 constituted by several holes in the bottom of the motor housing 4. The connection assembly 5 designed as a closing cover 18 prevents the coolant from escaping from the coolant circuit 12 by sealing the motor housing 4 liquid-tight.

[0032] As indicated by the arrows in Figures 1 and 2, the coolant enters the coolant circuit 12 through the coolant inlet 13, from where it can flow via the annular first coolant channel 14, the coolant redirection section 15 and the second annular coolant channel 16 to the coolant outlet 17, where it can leave the electric motor 1 again, or it can flow in the opposite direction through the coolant outlet 17, through the second coolant channel 16, through the coolant redirection section 15 and the first coolant channel to the coolant inlet 12. In the first coolant channel 14 between the motor housing 4 and the outer periphery of the stator 3, the coolant absorbs the magnetization and eddy current losses in the reverse circuit connection 7, while when it flows through the annular second coolant channel 14 in the gap between the rotor 2 and the stator 3, the resistive and eddy current heat losses in the stator windings 6 are dissipated. Since when the electric motor 1 is under high load, the majority of the power losses and therefore the waste heat occur in the stator windings 6, the cross-sections of the first 14 and the second 14 coolant channels are dimensioned in such a way that a turbulent flow is achieved in the area of ​​the second 16 coolant channel for optimal heat transfer. Since thermal oil is used as coolant for the electric motor 1, both the rolling bearings 10 in the connection assembly 5 and the rolling bearings 9 at the bottom of the motor housing 4 are open towards the second 16 coolant channel. This fluid-open connection to the rolling bearings 9, 10 allows both cooling and the supply of lubricant to the rolling bearings 9, 10.

[0033] The perspective exploded view of FIG. 3 further shows not only the motor housing 4, in which the rotor 2 and the stator 3 are accommodated and which is open at the front, but also the separate connection assembly 5. In addition to the actual closing cover 18, the connection assembly 5 has three electrical connection cables 19 which are electrically connected via associated plug-in connection means 20 with corresponding plug-in connection parts 21 of the stator winding 6 when the connection assembly 5 is mounted on the motor housing 4. The connection assembly 5 further comprises control lines 22 with associated plugs for connecting the motor electronics (connection and / or commutation electronics) 28 of the electric motor 1. When assembling the electric motor 1, the connection assembly 5 together with the closing cover 18 can be plugged and firmly fixed on the open side of the motor housing 4. In order to reliably seal the electric motor 1, in addition to the radial seal 23 to the inner circumference of the motor housing 4, an axial seal 24 can also be provided on the front flange of the motor housing 4. The use of the radial seal 23 in addition to the conventional axial seal 24 allows a very high level of sealing of the electric motor 1 against the environment and also a high durability of the sealing function. The plug-in connection part 21 connected to the stator windings 6 and the end of the rotor shaft 8 extend through a front flange 25 to fix the stator 3 and support the rotor 2 by means of the rotor shaft 8 guided in roller bearings 10.

[0034] FIG. 4 shows a cross section of the connection assembly 5 mounted on the motor housing 4. The connection assembly 5 together with the associated closing cover 18 is arranged at the open front of the cup-shaped motor housing 4, the interior of the electric motor 1 being sealed off from the environment, i.e. liquid-tight, by radial and axial seals 23 and 24 in the area of ​​the adjacent closing cover 18. The connection cable 19 is connected to the plug-in connection means 20 via the busbar 26. As can be clearly seen in the enlarged view of FIG. 4, the plug-in connection means 20 of the connection assembly 5 is configured as a plug socket 27 recessed in the housing of the connection assembly 5. In addition to the recessing in the housing of the connection assembly 5, an O-ring 35 is provided at the open end of the plug socket 27 facing the housing of the connection assembly 5, which improves the sealing of the plug socket 27 and thus also the electrical contact with the busbar 26 and the connection cable 19. The pin-shaped configured plug-in connection part 21 extends from the stator winding 6 through the front flange 25 and is received in the plug socket 27, allowing the electrical contact of the stator winding 6 of the stator 3.

[0035] In addition to the closing cover 18 with embedded plug sockets 27, and the associated bus bars 26 and connecting cables 19 for supplying power to the stator windings 6, the connection assembly 5 also comprises motor electronics 28, embedded in the housing of the connection assembly 5, with all components of the commutation electronics and a sensor 30, preferably an angular position sensor sensitive to magnetic fields. The sensor 30 detects the magnetic field of a control magnet 31 attached to the end of the rotor shaft 8 in order to control the operation of the electric motor 1.

[0036] During the manufacture of the connection assembly 5, in a first process step the motor electronics 28 with the printed circuit board 29, the electronic components for commutation, the sensors 30 and the connections of the control lines 22 are overmolded on all sides with a defined material thickness, preferably of a thermoplastic or alternatively of a thermosetting resin, for example by thermoplastic injection molding, thermosetting transfer molding or mould casting. In a second process step this component with the actual housing of the connection assembly 5 is overmolded or cast again with a thermoplastic or thermosetting plastic material to form the closing cover 18, so that also the possible holding positions from the first process step are reliably sealed against liquids in the electric motor 1.

[0037] As already shown in Fig. 3, the connection assembly 5 is detachably connected to the motor housing 4 by inserting the plug-in connection means 20 into the plug-in connection part 21 and further the closure cover 18 into the open end of the first side of the motor housing 4. In addition to the plug-in connection of the closure cover 18 with the plug-in connection means 20, in the embodiment shown in Fig. 3 the connection assembly 5 can be removably screwed to the motor housing 4 by means of screws 32 and corresponding threaded holes 33. Alternatively, the connection of the connection assembly 5 with the motor housing 4 can also be realised by a latching mechanism. The connection can also be designed to be non-detachable, for example by latching or gluing, to prevent the connection from loosening itself due to vibrations.

[0038] FIG. 5 shows a preassembled cable assembly 34 with three connection cables 19, each connected to a busbar 26 and a plug socket 27. The busbar 26, for example made of copper, can be connected to the plug socket 27 by pressing, welding or soldering. The connection cables 19 can then be connected to the busbar 26 by welding or soldering. Furthermore, the individual connection cables 19, the busbar 26 and the associated plug socket 27 are combined to form a common cable assembly 34, so that the cable assembly 34 can be added during the manufacture of the connection assembly 5 in a second processing step for manufacturing the housing of the connection assembly 5 and for forming the closure cover 18. During the manufacturing process of the connection assembly 5, the plug socket 27 is held by a forming tool in a defined position for connection to the plug-in connection piece 21, so that when the connection assembly 5 is later mounted on the motor housing 4, the plug socket 27 fits exactly into the position of the plug-in connection piece 21 provided in the motor housing 4. [Explanation of symbols]

[0039] 1 Electric motor 2 Rotors 3 Stator 4 Motor housing 5 Connection Assembly 6 Stator Winding 7 Reverse circuit connection 8 rotor shaft 9 Roller bearings 10 Roller bearings 12 Coolant circuit 13 Coolant inlet 14 First Coolant Channel 15 Coolant redirection section 16 Second Coolant Channel 17 Coolant outlet 18 Closure cover 19 Connection cable 20 Plug-in connection means 21 Plug-in connection parts 22 Control Line 23 Radial seal 24 Axial Seal 25 Front flange 26 Busbar 27 Socket 28 Motor electronics (connection and / or commutation electronics) 29 Printed Circuit Board 30 Sensors 31 Control Magnet 32 Screw 33 Screw hole 34 Cable Assembly 35 O-ring

Claims

1. An electronically rectified electric motor (1), The electric motor (1) is provided with a coolant circuit (12) for passing a coolant through it, and a liquid-cooled stator (3) having a hollow cylindrical stator winding (6) that does not contain iron. A rotor (2) is rotatably arranged concentrically with the stator (3), A motor housing (4) that houses the stator (3) and the rotor (2), Connection assembly (5), At least one electrical connection cable (19) for electrically connecting the stator winding (6), In an electronically rectified electric motor (1) having, The aforementioned connection assembly (5) Closing cover (18), At least one plug-in connection means (20) for electrically contacting the electrical connection cable (19) with the corresponding plug-in connection component (21) of the stator winding (6) of the stator (3), It has, An electronically rectified electric motor (1) is characterized in that the connection assembly (5) provides a liquid-tight seal of the motor housing (4), and a sealing element is provided between the housing of the connection assembly (5) and the plug-in connection means (20).

2. The stator (3) has a stator winding (6) having three stator winding phases and three plug-in connectors (21), each connected to one stator winding phase and located on the first side of the motor housing (4), The connection assembly (5) has three plug-in connection means (20), each connected to an electrical connection cable (19). The electronically rectified electric motor (1) according to claim 1, characterized in that...

3. The plug-in connection means (20) of the connection assembly (5) is configured as a plug socket (27). The electronically rectified electric motor (1) according to claim 1, characterized in that...

4. The corresponding plug-in connection component (21) of the stator winding (6) is configured as a connection pin. The electronically rectified electric motor (1) according to claim 3, characterized in that

5. An O-ring (35) is provided as a sealing element between the housing of the connection assembly (5) and the plug socket (27). The electronically rectified electric motor (1) according to claim 3, characterized in that

6. A radial seal (23) is provided between the connection assembly (5) and the motor housing (4). The electronically rectified electric motor (1) according to claim 1, characterized in that...

7. A cable assembly (34) is provided, The cable assembly (34) The aforementioned electrical connection cable (19) and, The aforementioned plug-in connection means (20), At least one busbar (26) for electrically connecting the electrical connection cable (19) to the plug-in connection means (20), Equipped with The electronically rectified electric motor (1) according to claim 1, characterized in that...

8. The cable assembly (34) Three electrical connection cables (19) and Three plug sockets (27) and Three busbars (26) and It has, The three electrical connection cables (19), the three plug sockets (27), and the three busbars (26) are mechanically connected to each other. The electronically rectified electric motor (1) according to claim 7, characterized in that...

9. The connecting assembly (5) is made of thermoplastic or thermosetting resin by injection molding or mold casting. The connection electronic circuit having the plug-in connection means (20) and the electrical connection cable (19) is embedded in the connection assembly (5). The electronically rectified electric motor (1) according to claim 1, characterized in that...

10. A rectifier electronic circuit is provided for rectifying the electric motor (1), The rectifier electronic circuit is embedded in the connection assembly (5). The electronically rectified electric motor (1) according to claim 9, characterized in that

11. The rectifier electronic circuit includes an integrated sensor (30) that detects the magnetic field of a diametrically controlled magnet (31) attached to the end of the rotor shaft (8). The electronically rectified electric motor (1) according to claim 10, characterized in that...

12. The integrated sensor (30) is an angular position sensor that is sensitive to a magnetic field. The electronically rectified electric motor (1) according to claim 11, characterized in that...

13. The magnetic field-sensitive angular position sensor detects the magnetic field of the diametrical control magnet (31) attached to the end of the rotor shaft (8). The electronically rectified electric motor (1) according to claim 12, characterized in that

14. The connecting electronic circuit and / or the rectifying electronic circuit are provided with an additional layer of thermoplastic or thermosetting resin applied in an upstream step by injection molding, transfer molding, or mold casting. The electronically rectified electric motor (1) according to claim 10, characterized in that...

15. The cooling material circuit (12) for passing the cooling material through the electric motor (1) is A first coolant channel (14) between the motor housing (4) and the outer circumference of the stator (3), A second coolant channel (16) between the inner circumference of the stator (3) and the rotor (2), A coolant direction changing section (15) for fluidly connecting the first coolant channel (14) and the second coolant channel (16), Equipped with The electronically rectified electric motor (1) according to claim 1, characterized in that...

16. The coolant direction changing section (15) is at least partially composed of the connecting assembly (5). The electronically rectified electric motor (1) according to claim 15, characterized in that

17. The second coolant channel (16) between the inner circumference of the stator (3) and the rotor (2) has a smaller cross-sectional area than the first coolant channel (14) between the motor housing (4) and the outer circumference of the stator (3). The electronically rectified electric motor (1) according to claim 15, characterized in that

18. The cooling circuit (12) has a cooling inlet (13) to the first cooling channel (14) which is arranged on the circumference of the motor housing (4). The electronically rectified electric motor (1) according to claim 15, characterized in that

19. The coolant circuit (12) has a coolant outlet (17) from the second coolant channel (16), and the coolant outlet (17) is located on the second side of the motor housing (4) opposite the connection assembly (5). The electronically rectified electric motor (1) according to claim 18, characterized in that

20. A connection assembly (5) for an electronically rectified electric motor (1) according to any one of claims 1 to 19, At least one electrical connection cable (19) and a closing cover (18) for the electronically rectified electric motor (1), At least one plug-in connection means (20) for electrically connecting the stator winding (6) to the electrical connection cable (19), The sealing element between the housing of the connection assembly (5) and the plug-in connection means (20), A connecting assembly (5) having the following:

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