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DE-102024003724-A1 - Method for producing a soldered joint and soldered joint

DE102024003724A1DE 102024003724 A1DE102024003724 A1DE 102024003724A1DE-102024003724-A1

Abstract

The invention relates to a method for producing a soldered composite (100) from at least one laminated core (10), a solder material (40), and a base body (50), wherein at least one end face (18) of the laminated core (10) to be soldered is connected to the base body (50) by means of a soldering process using the solder material (40). The soldering process is a friction soldering process in which the laminated core (10) and the base body (50) are brought into contact with the solder material (40) arranged between them. Under pressure exerted by the laminated core (10) and the base body (50), a relative movement (64, 66) of the laminated core (10) and the base body (50) is carried out until the solder material (40) is at least partially melted. The soldered composite (100) is formed after the liquid solder material (40) has solidified. The invention further relates to a soldered joint (100).

Inventors

  • Ralf Herrmann
  • Bernd Schietinger
  • Ulrich Schweizer

Assignees

  • Mercedes-Benz Group AG

Dates

Publication Date
20260513
Application Date
20241113

Claims (10)

  1. Method for producing a soldered joint (100) from at least one laminated core (10), a solder material (40) and a base body (50), wherein at least one end face (18) of the laminated core (10) to be soldered is connected to the base body (50) by means of a soldering process through the solder material (40), in which the soldering process is a friction soldering process in which the laminated core (10) and the base body (50) are brought into contact with the solder material (40) arranged between them, in which a relative movement (64, 66) of the laminated core (10) and the base body (50) is carried out under a contact pressure of the laminated core (10) and the base body (50) until the solder material (40) is at least partially melted, in which the soldered joint (100) is formed after the liquid solder material (40) has solidified.
  2. Procedure according to Claim 1 , wherein the solder material (40) is applied to the end face (18) of the lamination stack (10) to be soldered and/or to the base body (50) prior to the friction soldering process, in particular by printing or rolling, and/or wherein the solder material (40) is arranged between the end face (18) of the lamination stack (10) and the base body (50) prior to the friction soldering process, in particular as a paste, powder or in foil form.
  3. Procedure according to Claim 1 or 2 , wherein the brazing material (40) and/or the lamination stack (10) and/or the base body (50) are preheated before the friction brazing process, in particular wherein the brazing material (40) and/or the lamination stack (10) and/or the base body (50) are preheated by thermal radiation, in particular in an oven, or inductively.
  4. Method according to one of the preceding claims, wherein the friction brazing process is a friction brazing process, wherein a processing temperature of the brazing material (40) between 800°C and 1200°C, preferably at most 1150°C, is used, or wherein the friction brazing process is a friction soft brazing process, wherein a processing temperature of the brazing material (40) between 200°C and 500°C, preferably at most 450°C, is used.
  5. Method according to one of the preceding claims, wherein the relative movement of the lamination stack (10) and the base body (50) is a rotational movement (64) and/or a translational movement (66) and/or an oscillating movement of the lamination stack (10) and the base body (50) relative to each other.
  6. Method according to one of the preceding claims, wherein the base body (50) consists of a steel, in which at least one strength-enhancing measure is carried out locally or on the entire component before the brazing process, in particular wherein the strength-enhancing measure comprises at least one from the group consisting of case hardening, carbonitriding, nitriding, nitrocarburizing, tempering, induction hardening, laser hardening, electron beam hardening, precipitation hardening.
  7. Method according to one of the preceding claims, wherein a blank of the base body (50) is produced by a hot forming process, in particular wherein an increase in strength is generated by precipitation hardening from the hot forming temperature during the cooling process.
  8. Method according to one of the preceding claims, wherein the sheet metal stack (10) comprises electrical sheet metal material or is formed from electrical sheet metal material, and/or wherein sheets (12) of the sheet metal stack (10) are coated on at least one side surface (34, 36) with an electrically insulating coating (14).
  9. Soldered composite (100) consisting of at least one sheet metal package (10), a base body (50) and a solder material (40), produced by a method according to one of the preceding claims.
  10. solder joint after Claim 9 , designed as a component for an electromechanical application, in particular as a rotor or part of a rotor of an electromechanical application.

Description

The invention relates to a method for producing a soldered composite from at least one sheet metal stack, a solder material and a base body, as well as a soldered composite from at least one sheet metal stack, a base body and a solder material. Rotors of electric machines typically have a rotor carrier onto which a soft iron spiral lamination stack is soldered. The soldered connection is crucial for the mechanical attachment of the lamination stack to the rotor carrier. In the DE 10 2010 002 003 A1 An electric motor body is described which comprises a plurality of stacked sheet metal modules, each sheet metal module having at least two individual sheets bonded together by an adhesive. Furthermore, the sheet metal modules lie directly on top of one another. Alternatively, an intermediate material, different from the adhesive, is arranged between the sheet metal modules. The DE 10 2017 204 397 A1 This describes a laminated core segment for an electric axial flux machine, comprising a stack of electrically insulated laminations, a tooth formed by the stack and designed to receive a winding, and a trapezoidal yoke formed by the stack, which is configured to arrange multiple laminated core segments together in a circumferential polygonal shape. Furthermore, a stator segment for an electric axial flux machine is described, comprising a laminated core segment, wherein the tooth formed by the stack is occupied by a winding. Finally, a stator for an electric axial flux machine is described, comprising a plurality of laminated core segments arranged circumferentially in a polygonal shape and/or a plurality of stator segments arranged circumferentially in a polygonal shape. In the DE 10 2022 002 863 A1 An axial flux machine is disclosed, comprising a rotor with a rotor carrier, magnets held on the rotor carrier, and cooling channels running within the rotor carrier, each of which is permeable to cooling air for cooling the rotor. A valve arrangement allows the flow cross-section of the cooling air to be adjusted. One object of the invention is to provide an improved method for producing a soldered joint. Another task is to create a soldered joint that is produced using the improved process. The aforementioned tasks are solved using the characteristics of independent claims. Favorable embodiments and advantages of the invention will become apparent from the further claims, the description and the drawing. According to one aspect of the invention, a method for producing a brazed composite consisting of at least one laminated core, a brazing material, and a base body is proposed, wherein at least one end face of the laminated core to be brazed is connected to the base body by means of a brazing process using the brazing material. The brazing process is a friction brazing process in which the laminated core and the base body are brought into contact with the brazing material arranged between them. Under pressure, a relative movement of the laminated core and the base body is carried out until the brazing material is at least partially melted. The brazed composite is formed after the liquid brazing material solidifies. The proposed method is used for soldering a laminated core onto a base body, which is relevant in the context of manufacturing an electric machine. Specifically, the soldering of a wound electrical tape onto a rotor carrier is described. In contrast to conventional methods, where the components to be joined are subjected to heat in an oven to heat the solder to its melting temperature and thereby create the soldered joint, the method according to the invention proposes joining the components by means of a friction soldering process, in which the solder material in the contact area is heated by rubbing the components together to create a connection. This reduces energy consumption and the stress on the components involved. The proposed manufacturing process, friction brazing of a laminated core to a base body, results in lower heat input into the laminated core and the base body compared to conventional furnace brazing. The heat input is significantly shorter with the proposed method than with furnace brazing. Furthermore, component areas located away from the brazing zone are subjected to lower temperatures than components that are entirely within the furnace atmosphere. This results in less thermally induced damage to a coating on the sheet metal stack and/or less thermally induced damage to the base body and/or less component distortion in the soldered joint. Because high temperatures only need to be applied locally and for short periods in the soldering zone, a reduction in cycle time and thus a reduction in production costs can be achieved. Reducing energy consumption makes a positive contribution to reducing the CO2 footprint of the component. The short and thermally limited process reduces the thermal stress on an electrically insulating coating of the laminated core, especially the electrical steel co