DE102018221887A1 - Process for fully encapsulating a rotor with a rotor winding for an electrical machine - Google Patents

Abstract

The invention relates to a method for fully encapsulating a rotor (100) designed with a rotor winding for an electrical machine, comprising the following steps: - providing the prefabricated rotor (100); - providing at least one displacement body (200) which has at least one continuous channel (210 ); - standing arrangement of the rotor (100) and the displacement body (200) in a casting mold (300); - filling of the casting mold (300) with a casting compound, the casting compound passing through the channel (210) of the displacement body (200) the lower region (330) of the mold (300) is introduced and rises in the mold (300). The invention further relates to an alternative method in which a housing is used instead of the mold (300).

Description

The invention relates to a method for fully encapsulating a rotor formed with a rotor winding for an electrical machine.

A rotating electrical machine, such as a synchronous machine, has a fixed stator, which is also referred to as a stator, and a rotor running in the stator, which is also referred to as a rotor. Depending on the construction principle, the rotor is provided with permanent magnets or a rotor winding. Through a so-called full encapsulation of the rotor, in which existing cavities within the rotor winding and between the rotor winding and a rotor shaft or a rotor carrier are filled with a casting compound, the heat dissipation and the mechanical stability can be optimized with regard to dynamic and static loads.

The DE 10 2008 027 758 B4 describes a method for casting a rotor (1) designed with magnetic pockets (2). In order to achieve easier casting, at least one end plate (6) with an integrated distribution channel (7) is used. The casting compound is distributed over the distribution channel (7) into the individual magnet pockets (2). To carry out the method, the rotor in question must be designed with magnetic pockets.

The state of the art is also based on DE 10 2007 030 963 A1 pointed out.

The inventive method of claims 1 and 2 enable a simple and defect-free full potting of a rotor provided with a rotor winding for an electrical machine. Advantageous further developments and refinements of the invention result analogously for both methods from the dependent patent claims, the following description of the invention and the drawing.

• - Bereitstellen eines vorgefertigten Rotors, der insbesondere eine Rotorwelle (bzw. einen Rotorträger) und einen drehfest auf der Rotorwelle gelagerten bzw. darauf angeordneten Rotorkörper mit einer Rotorwicklung aufweist;
• - Bereitstellen wenigstens eines Verdrängungskörpers (s. u.), der wenigstens einen durchgängigen Kanal aufweist;
• - stehendes Anordnen des Rotors und des Verdrängungskörpers in einer Guss- bzw. Vergussform;
• - Befüllen der Gussform mit einer Vergussmasse, wobei die Vergussmasse durch den Kanal des Verdrängungskörpers hindurch in den unteren Bereich der Gussform eingeleitet wird bzw. einfließt und (dann) in der Gussform aufsteigt, sodass die Gussform mit dem darin angeordneten Rotor von unten mit der Vergussmasse befüllt wird.

The first method according to the invention for the full encapsulation of a rotor designed with a rotor winding for an electrical machine has at least the following steps, which can also be carried out automatically:

• - Providing a prefabricated rotor, which in particular has a rotor shaft (or a rotor carrier) and a rotor body with a rotor winding that is non-rotatably mounted or arranged on the rotor shaft;
• - Providing at least one displacement body (see below), which has at least one continuous channel;
• - Standing arrangement of the rotor and the displacer in a casting or casting mold;
• - Filling the casting mold with a casting compound, the casting compound being introduced or flowing through the channel of the displacement body into the lower region of the casting mold and (then) rising in the casting mold, so that the casting mold with the rotor arranged therein with the casting compound from below is filled.

• - Aushärten (oder zumindest Anhärten) der Vergussmasse, bspw. durch Wärmezufuhr; und/oder
• - Entformen des vergossenen Rotors aus der Gussform, wozu die Gussform insbesondere mehrteilig ausgebildet ist.

The first method according to the invention can also have the following steps:

• - hardening (or at least hardening) of the casting compound, for example by supplying heat; and or
• - De-molding of the cast rotor from the mold, for which purpose the mold is in particular made of several parts.

• - Bereitstellen des vorgefertigten Rotors (s. o.);
• - Bereitstellen wenigstens eines Verdrängungskörpers (s. u.), der wenigstens einen durchgängigen Kanal aufweist;
• - stehendes Anordnen des Rotors und des Verdrängungskörpers in einem Gehäuse;
• - Befüllen des Gehäuses mit einer Vergussmasse, wobei die Vergussmasse durch den Kanal des Verdrängungskörpers hindurch in den unteren Bereich des Gehäuses eingeleitet wird bzw. einfließt und (dann) im Gehäuse aufsteigt, sodass das Gehäuse mit dem darin angeordneten Rotor von unten mit der Vergussmasse befüllt wird.

The second method according to the invention has at least the following steps, which can also be carried out automatically:

• - Provision of the prefabricated rotor (see above);
• - Providing at least one displacement body (see below), which has at least one continuous channel;
• - Standing arrangement of the rotor and the displacer in a housing;
• - Filling the housing with a potting compound, the potting compound being introduced or flowing through the channel of the displacer into the lower region of the housing and (then) rising in the housing, so that the housing with the rotor arranged therein is filled with the potting compound from below becomes.

In the second method according to the invention, demolding of the cast rotor is not provided; that is, the housing becomes part of the rotor as a rotor housing.

In the rotor encapsulation according to the invention, at least one displacement body is used, which is arranged together with the rotor to be encapsulated in the casting mold or in its encapsulation space or in the housing or in its encapsulation space and then virtually cast in. By inserting a displacement body into the potting space, the potting volume can be reduced and potting compound saved (as in the DE 10 2007 030 963 A1 explained). Furthermore, a displacement body can also be used to fix the rotor winding. The at least one displacement body in the rotor body is preferred arranged and extends in particular over the entire axial length of the rotor body, wherein the at least one channel in the displacement body also extends over the entire axial length. The channel is preferably a groove or a bore. The displacement body can be made of plastic.

In the case of a standing arrangement, ie the rotor shaft is aligned vertically, a casting compound poured into the casting space from above would have to flow through the winding layers of the rotor winding, which is made even more difficult by the displacement body, so that there are inevitably defects (e.g. gaps, gaps, Bubble inclusions and the like) comes. It is therefore provided according to the invention that the casting mold or the housing with the rotor arranged therein is filled with the casting compound from below. This process can also be called increasing filling. When the filling increases, the existing cavities in the rotor, in particular within the rotor winding and between the rotor winding and the rotor shaft, are filled with the potting compound almost without any skin spots (full rotor potting). In particular, a thermosetting or cold-curing resin is used as casting compound (as in the DE 10 2008 027 758 B4 explained).

According to the invention, however, the potting compound is not supplied from below, which would require a correspondingly complex design and sealing of the casting mold or the housing, but via at least one channel of a displacer. This means in particular that the potting compound is supplied from above or at the upper end of the channel, flows down through the channel of the displacer and exits at the lower end of the channel and is introduced into the lower area of the mold or housing flows in. The “lower region” of the casting mold or the housing means in particular the casting mold base region or housing base region, which extends in particular between the casting mold base or the housing base and the rotor body arranged in the casting mold or in the housing, strictly speaking the lower rotor body end face .

The invention therefore provides for the displacement body to be used in such a way that the casting compound flows downwards through the displacement body and fills the casting mold or the housing from below. Existing molds can also be used for this. The casting mold or the housing can furthermore have means (with which at least one means is meant) which bring about or at least favor distribution of the casting compound in the lower region of the casting mold or the housing. These means are preferably arranged on the mold base or housing base. Such a means can be, for example, a ring-like distribution channel (as in the DE 10 2008 027 758 B4 explained).

It is preferably provided that the casting mold or the housing is filled under pressure by pressing the casting compound through the channel of the displacer into the lower region of the casting mold or the housing. This can be done, for example, using a filling device (as in the DE 10 2008 027 758 B4 explained). However, the casting mold or the housing is preferably filled in an injection molding machine which injects the casting compound directly (at the upper end) into the channel of the displacement body. This enables simple series production. Before the casting compound is injected, a vacuum can be created in the casting mold or the housing. However, open potting (under atmospheric conditions) is also possible.

A plurality of displacement bodies can be provided, which are arranged in a star or star shape in the rotor, preferably in the rotor body, in particular in a star shape around the rotor shaft, at least two displacement bodies being formed with (at least) one channel and when filling the casting mold or the housing the casting compound is simultaneously introduced through these (at least two) channels into the lower region of the casting mold or the housing. This allows the filling and cycle times to be reduced.

Alternatively, a star-shaped displacement body can be provided, which is arranged in the rotor, in particular in the rotor body, this displacement body being formed with at least two channels and, when filling the casting mold or the housing, the casting compound simultaneously through these (at least two) channels the lower area of the mold or the housing is introduced. This displacement body can also have integrated means, such as an annular distribution channel, which effect or at least favor distribution of the casting compound in the lower region of the casting mold or the housing. This displacement body is preferably formed in one piece.

• 1 zeigt schematisch in axialer Draufsicht einen zu vergießenden Rotor für eine elektrische Maschine.
• 2 veranschaulicht schematisch ein erfindungsgemäßes Verfahren zum Vollvergießen des Rotors aus 1 in einer Gussform.
• 3 veranschaulicht schematisch ein erfindungsgemäßes Verfahren zum Vollvergießen des Rotors aus 1 in einem Gehäuse.

Preferred embodiments of the invention are explained in more detail below with reference to the drawing. The features shown in the figures of the drawing and / or explained below can also be general features of the invention, regardless of certain combinations of features, and can further develop the invention accordingly.

• 1 shows schematically an axial plan view of a rotor to be cast for an electrical machine.
• 2nd schematically illustrates a method according to the invention for fully encapsulating the rotor 1 in a mold.
• 3rd schematically illustrates a method according to the invention for fully encapsulating the rotor 1 in one housing.

The in 1 shown rotor 100 has a rotor shaft 110 , which is designed as a hollow shaft, and a rotor body 120 with a rotor winding 130 on. The rotor winding 130 includes several winding sections around the rotor shaft 110 are arranged around. For the rotor 100 full potting is provided for the above reasons, so that in the rotor body 120 existing cavities with a potting compound, such as. B. a thermosetting resin.

The rotor is used for potting 100 together with several displacers 200 in a mold 300 arranged as in 2nd shown. The sinkers 200 are star-like in the rotor body 120 around the rotor shaft 110 arranged around as in 1 indicated. The mold 300 has a coat 310 and a bottom (mold bottom) 320 on. The rotor 100 and the elongated displacement body 200 are standing, ie axially vertical, in the mold 300 aligned, with the displacer 200 over the entire axial length of the rotor body 120 extend. In the embodiment shown, two of the displacement bodies have 200 a continuous channel in the axial direction 210 , which is designed as a bore.

When filling the mold 300 is the potting compound used from above simultaneously through the two channels 210 in the lower area 330 on the ground 320 the mold 300 (Mold bottom area) as illustrated by the downward arrows. The potting compound 300 is distributed in this lower area 330 and then rises as illustrated by the upward arrows, those in the rotor 100 or rotor body 120 existing cavities are largely filled with the casting compound free of defects. The mold 300 with the rotor arranged in it 100 is therefore filled from below with the casting compound (increasing mold filling), the supply of the casting compound from above through that with a channel 210 trained displacement body 200 through it. The floor 320 can have means, such as an annular distribution channel, which in the lower region 330 the mold 300 effect or at least favor a distribution of the casting compound

At the in 3rd Illustrated process is instead of a mold from which the potted rotor 100 after the casting compound has cured, a housing can be removed 400 used that is part of the rotor 100 will be removed from the mold. The housing 400 has a thin sleeve 410 on, which is preferably formed with a wall thickness of only a few tenths of a millimeter, an upper ring 412 , a lower ring 414 and a bottom (case bottom) 420 . The lower ring 414 and the floor 420 can be designed as a housing component. The floor 420 can have means, such as an annular distribution channel, which in the lower region 430 of the housing 400 effect or at least favor a distribution of the casting compound.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• DE 102008027758 B4 [0003, 0011, 0013, 0014]
• DE 102007030963 A1 [0004, 0010]

Claims (7)

Method for fully encapsulating a rotor (100) designed with a rotor winding (130) for an electrical machine, comprising the following steps: - Providing the prefabricated rotor (100); - Providing at least one displacement body (200) which has at least one continuous channel (210); - Standing arrangement of the rotor (100) and the displacer (200) in a mold (300); - Filling the casting mold (300) with a casting compound, the casting compound being introduced through the channel (210) of the displacer (200) into the lower region (330) of the casting mold (300) and rising in the casting mold (300). Method for fully encapsulating a rotor (100) designed with a rotor winding (130) for an electrical machine, comprising the following steps: - Providing the prefabricated rotor (100); - Providing at least one displacement body (200) which has at least one continuous channel (210); - Standing arrangement of the rotor (100) and the displacer (200) in a housing (400); - Filling the housing (400) with a potting compound, the potting compound being introduced through the channel (210) of the displacer (200) into the lower region (430) of the housing (400) and rising in the housing (400). Procedure according to Claim 1 or 2nd , characterized in that the casting mold (300) or the housing (400) in the lower region (330, 430) has means which cause the casting compound to be distributed. Procedure according to Claim 1 , 2nd or 3rd , characterized in that the mold (300) or the housing (400) is filled in an injection molding machine which injects the casting compound directly into the channel (210) of the displacement body (200). Procedure according to Claim 4 , characterized in that a vacuum is generated in the casting mold (300) or in the housing (400) before the casting compound is injected. Procedure according to one of the preceding Claims 1 to 5 , characterized in that a plurality of displacement bodies (200) are provided, which are arranged in a star-like manner in the rotor (100), at least two displacement bodies (200) being formed with a continuous channel (210) and the casting compound simultaneously through these channels (210) in the lower region (330, 430) of the casting mold (300) or the housing (400) is introduced. Procedure according to one of the preceding Claims 1 to 5 , characterized in that a star-shaped displacement body is provided, which is arranged in the rotor (100), this displacement body being formed with at least two channels and the casting compound simultaneously through these channels into the lower region (330, 430) of the casting mold (300 ) or the housing (400) is initiated.

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