Powder coating formulation for an insulation system of an electric machine

Patent metadata

Field	Value
Publication number	US-12580437-B2
Application number	US-202118043654-A
Country	US
Kind code	B2
Filing date	Aug 26, 2021
Priority date	Sep 3, 2020
Publication date	Mar 17, 2026
Grant date	Mar 17, 2026

Abstract

Various applications of the teachings of the present disclosure include a powder coating formulation suitable for producing an insulation system of an electrical machine. The formulation may include: a curable resin mixture; and spherical SiO 2 filler particles having a maximum particle diameter of 100 μm.

First claim

What is claimed is:

1 . A powder coating formulation suitable for producing an insulation system of an electrical machine, the formulation comprising:
a curable resin mixture; and spherical SiO2 filler particles having a maximum particle diameter of 100 μm; wherein the spherical SiO2 filler particles are present with a mass fraction of between 5 wt % and 65 wt % based on the total mass of the powder coating formulation; wherein the resin mixture is solid at room temperature and comprises:
a monomeric and/or oligomeric blend;
an epoxidized novolac blend with bisphenol A and/or bisphenol F diglycidyl etherb;
a chain-extended bisphenol A and/or F;
a diepoxidic or higher polyepoxidic carbon-based resin component; and/or
a monomeric and/or oligomeric resin blend based on alkyl- and/or aryl-polysiloxane; and
at least one further resin component comprising two or more glycidyl ester and/or glycidyl ether and/or hydroxyl functionalities; and/or
at least one compound acting as curing agent and based on dicyandiamide and/or on (poly)amine and/or on amino-functional and/or alkoxy-functional alkyl-/aryl-polysiloxane.

2 . The powder coating formulation of claim 1 , further comprising nonspherical SiO2 filler particles.

3 . The powder coating formulation of claim 1 , wherein the filler particles are crystalline and/or amorphous.

4 . The powder coating formulation of claim 1 , wherein the SiO2 filler particles comprise fused silica, quartz flour, and/or quartz glass.

5 . The powder coating formulation of claim 1 , wherein the filler particles have a particle size distribution D50 of between 1 μm and 50 μm, and/or a maximum particle diameter of 70 μm, and/or a thermal expansion coefficient of at most 20*10−6*K−1, and/or a relative permittivity of between 1 and 7 at 18° C. and 50 Hz.

6 . The powder coating formulation of claim 1 , wherein the filler particles are at least partly surface-modified.

7 . The powder coating formulation of claim 1 , comprising a sprayable powder coating material.

8 . The powder coating formulation of claim 1 , wherein, in the cured state it possesses a thermal expansion coefficient of at most 40*10−6*K−1.

9 . An electrical machine comprising:
a conductor; and an insulation system comprising a resin mixture filled with spherical SiO2 particles having a maximum particle diameter of 100 μm; wherein the spherical SiO2 filler particles are present with a mass fraction of between 5 wt % and 65 wt % based on the total mass of the powder coating formulation; wherein the resin mixture is solid at room temperature and comprises:
a monomeric and/or oligomeric blend;
an epoxidized novolac blend with bisphenol A and/or bisphenol F diglycidyl etherb;
a chain-extended bisphenol A and/or F;
a diepoxidic or higher polyepoxidic carbon-based resin component; and/or
a monomeric and/or oligomeric resin blend based on alkyl- and/or aryl-polysiloxane; and
at least one further resin component comprising two or more glycidyl ester and/or glycidyl ether and/or hydroxyl functionalities; and/or
at least one compound acting as curing agent and based on dicyandiamide and/or on (poly)amine and/or on amino-functional and/or alkoxy-functional alkyl-/aryl-polysiloxane.

10 . A method for producing an insulation system of an electrical machine, the method comprising:
coating insulation components with a powder coating formulation including a curable resin mixture filled with spherical SiO2 particles having a maximum particle diameter of 100 μm; and curing the formulation; wherein the spherical SiO2 filler particles are present with a mass fraction of between 5 wt % and 65 wt % based on the total mass of the powder coating formulation; wherein the resin mixture is solid at room temperature and comprises:
a monomeric and/or oligomeric blend;
an epoxidized novolac blend with bisphenol A and/or bisphenol F diglycidyl etherb;
a chain-extended bisphenol A and/or F;
a diepoxidic or higher polyepoxidic carbon-based resin component; and/or
a monomeric and/or oligomeric resin blend based on alkyl- and/or aryl-polysiloxane; and
at least one further resin component comprising two or more glycidyl ester and/or glycidyl ether and/or hydroxyl functionalities; and/or
at least one compound acting as curing agent and based on dicyandiamide and/or on (poly)amine and/or on amino-functional and/or alkoxy-functional alkyl-/aryl-polysiloxane.

11 . The method of claim 10 , wherein coating the insulation components includes:
preparing a substrate by heating and/or electrical contact; applying the powder coating formulation to the prepared substrate; and melting, drying, and/or partially gelling the powder coating formulation on the substrate.

12 . The method of claim 11 , wherein the powder coating formulation is applied and melted, dried, and/or partially gelled more than once.

13 . The method of claim 10 , carried out at least partly automatically.

Assignees

• Siemens Ag
• Innomotics Gmbh

Inventors

• Lang Steffen
• Maleika Marek
• Huber Jürgen
• Sponsel Lisa

Classifications

• H02K3/30 Primary

  Windings characterised by the insulating material · CPC title

• H01B3/002

  Inhomogeneous material in general · CPC title

• H02K15/105

  to the windings · CPC title

• H01B3/006

  Other inhomogeneous material · CPC title

• H02K15/12

  Impregnating, moulding insulation, heating or drying of windings, stators, rotors or machines · CPC title