DE102018206401A1 - Electric motor and method for producing the same - Google Patents

Abstract

The present invention relates to an electric motor (100) comprising at least one stator (1) flooded with coolant, having an inner stator ring (7) and an outer stator ring (8), and a rotor (2) rotatably mounted relative to the stator (1), wherein the inner stator ring (7) in the radial direction (R) has opened winding grooves (14) and, for at least partially closing the winding grooves (14) in the radial direction (R), with the outer stator ring (8) is connected, wherein at least one sealing unit (3 ), for coolant-tight foreclosure of the stator (1) from the rotor (2), extending from at least one end face of the stator (1) in a longitudinal direction (L) to at least one end shield (9) of the electric motor (100). Furthermore, the invention relates to a method for producing the electric motor (100) according to the invention.

Description

The present invention relates to an electric motor comprising a coolant-flowed stator having an inner stator ring and an outer stator ring, and a rotor rotatably mounted relative to the stator, the inner stator ring having radially-opened winding slots and at least partially closing the winding slots in the radial direction connected to the outer stator ring. The invention further relates to a method for producing such an electric motor.

In the prior art, various electric motors are known with coolant-flow stators. From the German patent application DE 4138268 A1 For example, various engines with liquid-filled stators are known. The motor claimed in this document has frontally on a stator sealed sealing rings, which seal the stator lamination against tube-like bearing flanges and wherein the two coil heads are acted upon by also sealed groove tubes with circulating through this cooling water. By these measures is dispensed with an otherwise common gap tube for sealing the stator space relative to the rotor space. The Statorraum is connected for increased cooling to an outer circulation system with a heat exchanger and remains constantly under pressure, so that a bubble-free cooling of the stator winding is achieved.

Disadvantages of the need for the introduction of flooded grooved tubes space requirement in the stator and the associated poor use of the available iron and the complex flameproof and also heat-insulating sealing of the grooved tubes and the transitions to the two end rings. The narrowed in the grooved tubes through the stator winding flow causes high pressure losses and requires a correspondingly high pump power for the circulation of the cooling water.

In the European patent application EP 1 271 747 A1 a medium-frequency electric motor, in particular in the form of a synchronous motor with a liquid-flooded stator, is proposed. The stator is separated from the rotor by a split tube, which is mounted liquid-tight in bearing flanges. Such a can, however, is unsuitable for use with high speed engines. An air gap between the rotor and stator is too large in such a structure and the magnetic fields are shifted accordingly disadvantageous.

Object of the present invention is to provide a high-speed electric motor with a coolant-flowed stator.

The above object is solved by the claims. In particular, the above object is achieved by the electric motor according to claim 1 and the method for producing the electric motor according to claim 14. Further advantages of the invention will become apparent from the dependent claims, the description and the drawings. In this case, features and details that are described in connection with the electric motor, of course, in connection with the inventive method for producing the electric motor and in each case vice versa, so with respect to the disclosure of the individual aspects of the invention can always be taken reciprocally.

According to a first aspect of the present invention, an electric motor with at least one coolant-flow-through stator, which has an inner stator ring and an outer stator ring, and a rotor rotatably mounted relative to the stator is proposed. The inner stator ring has winding grooves opened in the radial direction and is connected to the outer stator ring for at least partially closing the winding slots in the radial direction. Furthermore, at least one sealing unit, for coolant-tight foreclosure of the stator from the rotor, extends from at least one end face of the stator in a longitudinal direction to at least one end shield of the electric motor.

The inventive arrangement of the stator components and the sealing unit, an efficient cooling of windings in the winding grooves can be achieved. On the integration of a canned can be dispensed with. The associated problems, as mentioned above, can be remedied thereby. In particular, in the electric motor according to the invention a particularly small air gap between the stator and the rotor can be realized. This in turn means that less magnetic material is needed and costs can be saved accordingly.

By a closed groove Stromverdrängeffekte can be reduced at inner conductors of the electric motor. Furthermore, splashing losses can be avoided by a dry rotor chamber.

The present electric motor can be configured as an internal rotating or externally rotating electric motor. In the case of an internal rotating electric motor, the rotor is mounted rotatably in the radial direction at least in sections within the stator relative thereto. In an externally rotating electric motor, the rotor is at least partially rotatably mounted in the radial direction outside of the stator relative to this. Basically, a synchronously operating electric motor, so a Synchronous motor and an asynchronously operating electric motor, so an asynchronous motor operated with the structure of the invention and are cooled accordingly. In an asynchronous motor according to the invention, a relatively large magnetic air gap can advantageously be prevented by omission of the can.

In an electric motor according to the invention, a groove to the air gap, which is located between the rotor and stator is closed by the at least one sealing unit at least one point. By means of thermal treatment of the sealing unit, an insulating section can be formed thereon, by means of which the magnetic conductivity of the closed groove toward the air gap is reduced to a predefined value. As a result, magnetic short circuits between teeth of the stator can be avoided.

In the air gap, a drainage device for the removal of fluid that enters the air gap, at least partially integrated. In such a case, fluid leakage into the air gap can be tolerated in small quantities.

In an electric motor according to the invention form coils can be used which are wound orthocyclically. With such form coils, a high fill factor can be achieved and voltages between adjacent turns can be reduced. In addition, can be made by Roebel according to the invention, in particular the two-part structure of the stator, and by which also the proximity effect can be reduced.

The coolant for cooling the stator is preferably a liquid, in particular oil. That is, the electric motor preferably has a cooling liquid, in particular oil-flooded stator. With this coolant, the electric motor can cool particularly effective.

The at least one sealing unit extends to the coolant-tight foreclosure of the stator from the rotor, preferably from at least one end face of the inner stator ring or at least one end face of the outer stator ring in the longitudinal direction to at least one end shield of the electric motor. More specifically, the at least one sealing unit for coolant-tight partitioning of the stator from the rotor extends at least one end face of the inner stator ring in the longitudinal direction to at least one end shield of the electric motor with an internal rotating design of the electric motor. In an externally rotating embodiment of the electric motor, the at least one sealing unit for coolant-tight foreclosure of the stator preferably extends from the rotor from at least one end face of the outer stator ring in the longitudinal direction to at least one end shield of the electric motor. That is, the sealing unit extends only from the inner and / or outer stator ring to the at least one end shield. The sealing unit thus does not cover the entire stator in the radial direction, but only an outer edge region of the inner stator ring or of the outer stator ring.

Under a foreclosure is a seal, in particular to understand a fluid-tight seal. The partition is designed to prevent a cooling fluid transfer from the stator in the direction of the rotor. The sealing unit is designed in particular for oil-tight foreclosure of the stator of the rotor. Under the coolant-tight foreclosure of the stator of the rotor in particular a coolant-tight foreclosure of a stator, in which the stator is located in the electric motor, from a rotor region in which the rotor is located in the electric motor to understand.

The at least one sealing unit can be designed in one piece or in several parts. The at least one sealing unit preferably has a maximum thickness in the radial direction which is smaller, preferably many times smaller, than the maximum thickness of the inner and / or outer stator ring in the radial direction. The at least one sealing unit is accordingly designed to save space in the electric motor.

According to a further embodiment of the present invention, it is possible that in an electric motor, the inner stator ring has a plurality of stator laminations which are pressed against the coolant-tight foreclosure of the stator by the rotor coolant-tight manner. That is, the connection of the individual stator laminations is made such that they are fluid-tight. As a result, the coolant-tight foreclosure of the stator relative to the rotor can be ensured. The geometry of the stator is designed accordingly such that the sheets are closed to the air gap.

Furthermore, it is possible that in an electric motor according to the invention, the at least one sealing unit biased between the at least one end face of the stator and the at least one end shield arranged, in particular pressed. The clamped or pressed arrangement of the sealing unit can be dispensed with additional fastening means. The sealing unit is preferably designed in one piece in this case. Furthermore, the sealing unit is preferably made of plastic or at least substantially of plastic. If only a few fasteners are required, corresponding costs can be saved and a logistical effort can be reduced. The one-piece Construction of the sealing unit also leads to a lower, local degree of complexity of the electric motor. The bias of the sealing unit may be performed with an additional spring element, or the sealing unit itself has the desired or a correspondingly predefined spring constant or spring rate. The at least one sealing unit is in particular in the longitudinal direction, ie in a direction from end face to end face of the stator, biased.

In an electric motor according to the present invention, it is also possible that the at least one sealing unit consists of non-magnetic material or consists at least substantially of non-magnetic material. This hysteresis and eddy current losses can be easily prevented in the electric motor. In the present case, the sealing unit preferably consists entirely or at least 80% of nonmagnetic material.

Furthermore, it is possible that in the present electric motor, the at least one sealing unit comprises a main sealing element and at least one auxiliary sealing element, wherein the at least one auxiliary sealing element between an end face of the stator and the main sealing element and / or between the at least one End shield and the main sealing element arranged, in particular pressed, is. The division of the sealing unit in the main sealing element and the at least one auxiliary sealing element leads to increased flexibility in the installation of the sealing unit. Thus, for example, first the main sealing element can be brought into position and then only needs to be fixed with the at least one auxiliary sealing element. For maintenance work, it would also be sufficient to replace only the at least one auxiliary sealing element and to continue to use the main sealing element. This can be saved accordingly costs. The main sealing element preferably consists completely or at least substantially completely of a non-magnetic material, in particular plastic.

It may be of further advantage if, in an electric motor according to the invention, the main sealing element has a tubular body or is configured in the form of a tubular body. That is, the main sealing element is sleeve-shaped. The main sealing element may accordingly be provided as the main sealing sleeve. The tubular body is a geometrically particularly easy to manufacture component. In addition, a main sealing member configured as a pipe body or a sealing sleeve can be easily integrated into the electric motor, that is, the assembly can be performed particularly easily with respect to this component. The main sealing element has in the radial direction preferably over the entire or substantially the entire length of the main sealing element the same or substantially the same diameter. Only at at least one end section of the main sealing element can these each have a receiving section for receiving the at least one auxiliary sealing element, wherein the diameter of the main sealing element in the radial direction on the receiving section is greater or smaller than at the remainder of the main sealing element. In the receiving section, for example, the diameter of the main sealing element may be less than 10% smaller than at the remainder of the main sealing element.

Moreover, it is possible that in an electric motor according to the present invention, the at least one auxiliary sealing element has an O-ring or is configured as such. An O-ring is characterized by a particularly simple and cost-effective production. As a rule, O-rings can be purchased as a standard component, which means that a costly and logistically complex custom-made product can be dispensed with. The O-ring is preferably made as a rubber ring. In place of the O-ring and a molded seal can be used.

According to a further embodiment variant of the present invention, it is possible that in an electric motor, the at least one sealing unit with the at least one end face of the stator and / or the at least one end shield is glued coolant-tight. In this case, it is possible to dispense with the auxiliary sealing element, for example in the form of the O-ring. By bonding a particularly dense foreclosure of the stator relative to the rotor can be achieved. Furthermore, it is possible to dispense with additional components during the bonding. This reduces the degree of complexity of the electric motor and leads to correspondingly reduced component costs.

In addition, it is possible that in an electric motor according to the present invention, the inner stator ring is at least partially positively engaged with the outer stator ring, wherein the outer stator is mounted non-destructively displaceable to the inner stator ring. Due to this construction, the electric motor can be assembled and disassembled particularly easily. After the winding grooves of the inner stator ring are filled with windings or coils, the outer stator ring can be easily pushed onto the inner stator ring. In such an assembled state, the inner stator ring is preferably positively engaged with the outer stator ring in four directions.

It is also possible in an electric motor according to the invention that the inner stator ring in the radial direction has outwardly directed tooth portions, between which the Winding grooves are configured, and the outer stator ring yoke sections, which are in each case with the tooth sections in a form-fitting engagement. By this construction, the positive connection between the inner stator ring and the outer stator ring and the displaceable arrangement of the inner stator ring to the outer stator can be realized simply and compactly. The tooth portions are understood to be projections that extend radially outward toward the outer stator ring. The yoke portions have recesses in the radial direction within the outer stator ring, which are complementary or substantially complementary to the tooth portions or to end portions of the tooth portions for positively receiving the same configured.

Furthermore, it may be advantageous if, in the case of an electric motor according to the invention, the tooth sections with the yoke sections each form a dovetail connection. By this type of connection, a secure and yet easily releasable mold combination between the inner stator ring and the outer stator ring can be realized.

In the winding grooves, a cooling channel for conducting a coolant for cooling windings in the winding grooves is configured in each case in a design variant of the present invention according to the invention. A large part of the losses occurring in the electric motor occurs in the winding. Accordingly, heat can be dissipated directly from the source through cooling channels in the winding grooves. As a result, copper losses can be reduced or kept low at the same power.

In an electric motor according to the invention, it is also possible that the windings in the winding grooves each having an inner winding portion and an outer winding portion, wherein the cooling channel for guiding the coolant in the longitudinal direction of the winding grooves between the inner winding portion and the outer winding portion, and to each of the inner Winding portion and the outer winding portion around, is configured. As a result, the winding sections can be cooled particularly effectively. According to the invention, the winding sections are therefore surrounded both inside in the radial direction and in the radial direction outside of the coolant and are cooled accordingly at these points.

In the present case, the electric motor is preferably designed in the form of a high-frequency motor or a high-speed motor for a functional operation with a rotational speed in a range between 10,000 rpm and 30,000 rpm.

• - Bereitstellen des inneren Statorrings,
• - Einbringen der Wicklungen in die Wicklungsnuten in Radialrichtung von außen nach innen,
• - Verdichten der Wicklungen,
• - Aufschieben des äußeren Statorrings auf den inneren Statorring zum wenigstens teilweisen Schließen der Wicklungsnuten in Radialrichtung,
• - Bereitstellen eines Lagerschildes an jeweils einer Stirnseite des Stators, und,
• - Positionieren von einer Dichteinheit zur kühlmitteldichten Abschottung des Stators vom Rotor jeweils zwischen einer Stirnseite des Stators und einem Lagerschild des Elektromotors.

According to another aspect of the present invention, there is provided a method of manufacturing an electric motor having a stator and a rotor as discussed in detail above. The method comprises the following steps:

• Providing the inner stator ring,
• Introducing the windings into the winding grooves in the radial direction from outside to inside,
• - compacting the windings,
• Sliding the outer stator ring on the inner stator ring for at least partially closing the winding grooves in the radial direction,
• - Providing a bearing plate on each one end face of the stator, and,
• - Positioning of a sealing unit for coolant-tight foreclosure of the stator from the rotor in each case between an end face of the stator and a bearing plate of the electric motor.

Thus, the inventive method brings the same advantages as they have been described in detail with respect to the electric motor according to the invention. The above method steps need not be performed in the order shown. Thus, for example, first a sealing unit can be positioned on the stator and then a bearing plate on the sealing unit, or vice versa.

The type of winding provision according to the invention considerably reduces the risk of damaging the insulation of the windings by a winding process of the windings. Due to the present possible winding process and the possibility of insert from the outside, in principle, water can be used as a cooling medium. By introducing the windings from the outside, these can be compacted particularly easily and effectively in the winding grooves. The electric motor can thereby be provided inexpensively with a high power density.

Further, measures improving the invention will become apparent from the following description of various embodiments of the invention, which are shown schematically in the figures. All of the claims, description or figures resulting features and / or advantages, including structural details and spatial arrangements may be essential to the invention both in itself and in the various combinations.

• 1 eine Schnittansicht eines Elektromotors gemäß einer bevorzugten Ausführungsform der vorliegenden Erfindung,
• 2 eine vergrößerte Schnittansicht eines Details des in 1 dargestellten Elektromotors, und
• 3 eine vergrößerte Schnittansicht eines Details des in 1 dargestellten Elektromotors.

Each show schematically:

• 1 a sectional view of an electric motor according to a preferred embodiment of the present invention,
• 2 an enlarged sectional view of a detail of in 1 shown electric motor, and
• 3 an enlarged sectional view of a detail of in 1 illustrated electric motor.

Elements with the same function and mode of action are in the 1 to 3 each provided with the same reference numerals.

In 1 is a sectional view A - A an electric motor 100 shown in a preferred embodiment. The electric motor 100 , which is designed as a high-frequency motor, has a coolant-flooded stator 1 with an inner stator ring 7 (S. 2 ) and an outer stator ring 8th , as well as relative to the stator 1 rotatably mounted rotor 2 on. The in 1 illustrated electric motor 100 is as an internal rotating electric motor 100 executed. That is, the rotor 2 is rotatable within the stator 1 stored.

The inner stator ring 7 points in the radial direction R opened winding grooves 14 on and is to close the winding grooves 14 in the radial direction R with the outer stator ring 8th connected. More specifically, the inner stator ring stands 7 partially positively with the outer stator ring 8th engaged, wherein the outer stator ring 8th to the inner stator ring 7 is mounted non-destructively displaceable. The inner stator ring 7 also has a plurality of stator laminations, which are the coolant-tight foreclosure of the stator 1 from the rotor 2 Are coolant-tight pressed together. An air gap 10 between the stator 1 and the rotor 2 is relatively small.

The electric motor 100 also has a sealing unit 3 on, which, to the coolant-tight foreclosure of the stator 1 from the rotor 2 , from each end of the stator 1 in a longitudinal direction L to the respective end shield 9 of the electric motor 100 extends. The sealing unit 3 each consists of plastic.

2 shows an enlarged sectional view V - V from the in 1 illustrated electric motor 100 , As in 2 shown, the inner stator ring 7 in the radial direction R outwardly directed tooth sections 15 on, between which the winding grooves 14 are designed. The outer stator ring 8th has complementary to the tooth sections 15 designed yoke sections 16 on that with the teeth sections 15 according positively engage. More precisely, the tooth sections are 15 with the yoke sections 16 in a connecting section 17 via a dovetail connection in engagement.

Further, in the winding grooves 14 one cooling channel each 11 for conducting a coolant for cooling windings 12 . 13 in the winding grooves 14 designed. The windings 12 . 13 in the winding grooves 14 each have an inner winding section 12 and an outer winding portion 13 on, with the cooling channel 11 for conducting the coolant in the longitudinal direction L the winding grooves 14 between the inner winding section 12 and the outer winding portion 13 , as well as around the inner winding section 12 and the outer winding section 13 around, is designed. That is, the inner winding section 12 and the outer winding portion 13 be in the longitudinal direction L in each case at least partially completely flows around coolant. As the coolant oil is used in the present case. That is, the stator 1 is oil-filled.

3 shows an enlarged sectional view A of the in 1 illustrated electric motor 100 to explain the sealing unit 3 , As in 3 shown, the sealing unit 3 a main sealing element 4 and two auxiliary sealing elements 5 . 6 on. The main sealing element 4 is designed in the form of a sealing sleeve or a tubular body. The between stator 1 or end face of the inner stator ring 7 and main sealing element 4 positioned auxiliary sealing element 5 is designed as an O-ring.

The between main sealing element 4 and end shield 9 positioned auxiliary sealing element 6 is also designed in the form of an O-ring.

With reference to the 1 to 3 Subsequently, a method for producing the illustrated electric motor 100 described. According to the method, first, the inner stator ring 7 provided. Subsequently, the windings or the inner winding sections 12 and outer winding sections 13 in the winding grooves 14 in the radial direction R introduced and compressed from outside to inside. Then the outer stator ring 8th for closing the winding grooves 14 on the inner stator ring 7 pushed. Afterwards, bearing shields become 9 and sealing units 3 to the coolant-tight foreclosure of the stator 1 from the rotor 2 positioned such that a sealing unit 3 each between an end face of the stator 2 and a bearing plate 9 is arranged. In the illustrated internal rotating electric motor 100 is the sealing unit 3 each between an end face of the inner stator ring 7 and a bearing plate 9 arranged. In an externally rotating electric motor 100 would be the sealing unit 3 each between an end face of the outer stator ring 7 and a bearing plate 9 arranged.

The invention, in addition to the illustrated embodiments, further design principles to. Ie. the invention should not be considered limited to the embodiments explained with reference to the figures.

LIST OF REFERENCE NUMBERS

1

stator

2

rotor

3

sealing unit

4

Main sealing member

5

Auxiliary sealing element

6

Auxiliary sealing element

7

inner stator ring

8th

outer stator ring

9

end shield

10

air gap

11

cooling channel

12

inner winding section

13

outer winding section

14

winding groove

15

tooth portion

16

yoke

17

connecting portion

100

electric motor

R

radial direction

L

longitudinal direction

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

• DE 4138268 A1 [0002]
• EP 1271747 A1 [0004]

Claims (14)

Electric motor (100) comprising at least one stator (1) filled with coolant, with an inner stator ring (7) and an outer stator ring (8), and a rotor (2) rotatably mounted relative to the stator (1), the inner stator ring (7) in the radial direction (R) has opened winding grooves (14) and, for at least partially closing the winding grooves (14) in the radial direction (R), connected to the outer stator ring (8), characterized in that at least one sealing unit (3), for coolant-tight foreclosure of the stator (1) from the rotor (2), extending from at least one end face of the stator (1) in a longitudinal direction (L) to at least one bearing plate (9) of the electric motor (100). Electric motor (100) after Claim 1 , characterized in that the inner stator ring (7) has a plurality of stator laminations, the coolant-tight foreclosure of the stator (1) from the rotor (2) are pressed together coolant-tight. Electric motor (100) according to one of the preceding claims, characterized in that the at least one sealing unit (3) biased between the at least one end face of the stator (1) and the at least one end shield (9) arranged, in particular pressed. Electric motor (100) according to one of the preceding claims, characterized in that the at least one sealing unit (3) consists of non-magnetic material or at least substantially consists of non-magnetic material. Electric motor (100) according to one of the preceding claims, characterized in that the at least one sealing unit (3) has a main sealing element (4) and at least one auxiliary sealing element (5, 6), wherein the at least one auxiliary sealing element (5 , 6) between an end face of the stator and the main sealing element (4) and / or arranged between the at least one bearing plate (9) and the main sealing element (4), in particular pressed. Electric motor (100) after Claim 5 , characterized in that the main sealing element (4) has a tubular body or is designed in the form of a tubular body. Electric motor (100) according to one of Claims 5 to 6 , characterized in that the at least one auxiliary sealing element (5, 6) has an O-ring or is designed as such. Electric motor (100) according to one of the preceding claims, characterized in that the at least one sealing unit (3) with the at least one end face of the stator (1) and / or the at least one end shield (9) is glued coolant-tight. Electric motor (100) according to one of the preceding claims, characterized in that the inner stator ring (7) is at least partially positively connected to the outer stator ring (8) into engagement, wherein the outer stator (8) to the inner stator ring (7) mounted non-destructively displaceable is. Electric motor (100) according to one of the preceding claims, characterized in that the inner stator ring (7) in the radial direction (R) outwardly facing tooth portions (15), between which the winding grooves (14) are designed, and the outer stator ring (8 ) Yoke portions (16) which are in each case with the tooth portions (15) in a form-fitting engagement. Electric motor (100) after Claim 10 , characterized in that the tooth portions (15) with the yoke portions (16) each form a dovetail joint. Electric motor (100) according to one of the preceding claims, characterized in that in the winding grooves (14) in each case a cooling channel (11) for conducting a coolant for cooling windings (12, 13) in the winding grooves (14) is configured. Electric motor (100) after Claim 12 characterized in that the windings (12, 13) in the winding grooves (14) each have an inner winding portion (12) and an outer winding portion (13), the cooling passage (11) for conducting the coolant in the longitudinal direction (L) of Winding grooves (14) between the inner winding portion (12) and the outer winding portion (13), and around each of the inner winding portion (12) and the outer winding portion (13) around, is configured. A method of manufacturing an electric motor (100) comprising a stator (1) and a rotor (2) according to any one of the preceding claims, comprising the steps of: - providing the inner stator ring (7), - inserting the windings (12, 13) in the Winding grooves (14) in the radial direction (R) from outside to inside, - compressing the windings (12, 13), - Sliding the outer stator ring (8) on the inner stator ring (7) for at least partially closing the winding grooves (14) in the radial direction (R), - Providing a bearing plate (9) on each one end face of the stator (1), and - positioning of a sealing unit (3) for coolant-tight foreclosure of the stator (1) from the rotor (2) respectively between an end face of the stator (2) and a End shield (9) of the electric motor (100).

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