DE102007047573A1 - Motor i.e. electromotor, for driving e.g. stirring device in food processing, has housing with inorganic, non-metallic coating at external side, where coating is hydrophobic, and housing is made of steel or light metal i.e. aluminum - Google Patents

Abstract

The motor (1) has a housing (2) with an inorganic, non-metallic coating (6) at an external side (5), where the coating is made of a material that is selected from a group consisting of ceramic, metallic oxide, metallic nitride, metallic oxynitride, metallic carbide, metallic fluoride, metallic sulfide and carbon. The coating has silicon oxide, silicon nitride and silicon oxynitride as main components and has a thickness in the range of 3 to 10 micrometers. The coating is hydrophobic, and the housing is made of steel or light metal i.e. aluminum.

Description

The The invention relates to a motor, in particular an electric motor, with a housing.

such Engines, especially electric motors, are used in a variety of ways Areas used for drive or actuation. For example engines are used in food processing and manufacturing or / and chemical and pharmaceutical packaging processes Industry and medical technology used, where they partly with come into contact with food, medicines and the like, which places high demands on hygiene and cleaning become.

such Motors therefore often have a stainless steel housing, which on the one hand food compatible and on the other hand is inert to many detergents.

task the present invention is to provide a field of application of an engine, in particular electric motor, to expand, and in particular a cleaning behavior to improve.

These The object is achieved by a motor having the features of claim 1, a method for Coating a housing of an engine with the features of claim 13 and a use of an engine having the features of claim 17. Advantageous embodiments and developments are in the respective dependent claims specified.

at a motor according to the invention with a housing, this has an inorganic, at least on an outer side, non-metallic coating on. This will be a resistance improved over aggressive chemical cleaning agents, so that due to a more aggressive cleaning hygiene improved. Advantageously, corrosion of stainless steel, in particular the commonly used V2A or V4A steels, be avoided. This allows, for example, the use strong chlorine-containing detergent, which without the inventive coating would attack the stainless steel. Advantageously, can also cheaper materials for the housing be provided. In particular, a cost-effective Material such as aluminum can be used as housing material.

When Engine may be provided an engine of any kind, in particular an internal combustion engine, wherein preferably a housing temperature below 500 ° C, an electric motor, Hydraulic motor or a heat engine or the like. Preferably the engine is an electric motor. An electric motor can be both a permanent magnet synchronous machine, an asynchronous motor, a stepping motor or a linear actuator motor act. At a Stepper motor may in particular a hybrid stepping motor or a variable Reluctance be provided. In particular, a linear actuator is a permanently energized electric motor with integrated ball screw intended.

Preferably is also a periphery of the case at least on one Outside with an inorganic, non-metallic coating Mistake. In particular, this can be for sensors such as Angle encoder for position / angle detection of a motor axis or Like. Be provided. In particular, an at least partially outside the housing located attachment or a component The motor must be coated accordingly.

The Housing is designed in particular so that it is the engine encapsulates. Preferably, the housing is at least against sprayed Water or the like sealed.

The Coating is preferably on all sides on the outside attached to the housing. However, it can also be provided be to provide these only in places that are particular in a cleaning are exposed. In particular, the housing may be an interior coating, at least in an edge region adjacent to the outside, exhibit. Preferably, this reduces corrosion in the case a leakage and / or in the case of a creeping in of cleaning fluid in existing between several parts of the housing columns.

According to one Further, the coating has at least one ceramic Shift up. This preferably allows a high temperature resistance of at least 200 ° C, preferably at least 500 ° C. In particular, the layer is physiologically harmless and thus food grade.

One Layer material of the particular ceramic coating is according to a Embodiment selected from the group comprising metal oxide, Metal nitrite, metal oxynitride, metal carbide, metal fluoride, metal sulfide and diamond-like carbon. As oxide is in particular Alumina, titania, zinc oxide, tin oxide, zirconia, hafnia, niobium oxide, Tantalum oxide or bismuth oxide provided. It can also be mixtures be provided various oxides. In addition to those for metal oxides mentioned metals can be used as metal for metal nitrides in particular Boron be used. As carbide, for example, boron carbide or Silicon carbide used. As a fluoride, for example, aluminum fluoride or Magnesium fluoride provided.

Under diamond-like carbon layers are in particular so-called DLC layers, amorphous diamond-like carbon layers, to understand.

An inexpensive and simultaneously effective coating can be made possible by the fact that the coating comprises silicon oxide, silicon nitrite or silicon oxynitrite as the main constituent. Preferably, silicon oxide is provided as the main component. The use of silicon oxide allows a colorless, transparent and preferably non-porous coating on the housing. In particular, the housing is surrounded with a glass-like coating which essentially has the known inert properties of glass. Preferably, a high durability of the coating is achieved due to a high resistance to UV radiation. Preferably, a resistance to UV irradiation according to ISO 4892 reached over 7000 hours. Stability in a salt spray test is preferably achieved up to 1000 hours. Furthermore, the layer is particularly resistant to boiling water. Preferably, a resistance in a Kesternich test of at least 15 cycles is achieved.

A improved lifetime of the coating can be achieved by the coating has at least one adhesion-promoting layer. This preferably allows better adhesion of a ceramic layer on a metallic housing, in particular on a stainless steel case. As a bonding layer is an especially few nanometers thick metal layer, for example Titanium or chrome, provided. It can also be a gradient layer be provided, in which a degree of oxidation starting from a completely metallic primer layer immediately on the housing continuously increases in the slice growth direction.

A especially high resistance to aggressive cleaning agents preferably achieved when the coating at least largely acid-resistant and / or alkali-resistant, especially in a pH range from about 2 to 12, especially from 3 to 12. The pH is while based on a temperature of 25 ° C.

Regarding a thickness of the coating is provided that this between 0.1 and 100 microns, in particular between 1 and 30 microns and in particular between 3 and 10 microns. The thickness is preferably chosen so that both a completely closed, closed-pore layer as also a sufficient elasticity is achieved. In particular, elongation results from temperature changes during operation of the engine due to different thermal expansion coefficients from engine and coating not to cracks or micro cracks in the Coating. A thickness of the layer with silica as a main component is for example 2 to 5 microns.

One improved dripping behavior of the motor housing, for example be achieved by the coating suitable surface properties having. In a first embodiment it is provided that the Coating is hydrophobic. The coating has a water contact angle more than 90 °, preferably more than 120 °, on. This is achieved for example by a surface energy the coating by incorporation of, for example, fluorine or other suitable dopants is reduced. In particular, favored this is a sliding or rolling of water droplets or liquid droplets. By a faster drying is in particular a formation of germs counteracted.

In another embodiment provides that the coating is hydrophilic and has a water contact angle of less than 90 °. Especially the coating has a water contact angle of less than 45 °. As a hydrophilic coating, for example uses a coating comprising silica as a main component. With a hydrophilic Beschich device is preferably causes that a uniform, thin liquid film, in particular, forms a cleaning fluid film, which evaporates faster compared to single drops, so that liquid residues avoided as possible become.

The tightness of the engine coated according to the invention preferably reaches the protection class IP67 according to the standard IEC60529 , so that a reliability improves. The housing is on the one hand tight against the ingress of dust at a negative pressure of 20 mbar in particular in the housing and on the other hand waterproof with temporary submersion in water.

to Achieving this level of protection is the housing of the motor provided for example with appropriate seals. Especially can be provided to design the housing in one piece, this being open on one side and provided with a flange, which is used for mounting the motor.

A long service life of the motor housing is preferably achieved if the housing material is stainless steel or a light metal, preferably aluminum. The use of stainless steel reduces on the one hand a rust formation and on the other hand at least largely also a contamination of possibly with the motor housing in contact tre food in the event of coating failure. As stainless steel in particular V2A or V4A steel is provided. For a lighter and more cost-effective design, however, a less inert metal may be provided. Preferably, an aluminum housing can be used, which is reliably protected by the coating.

to Achieving an improved dripping or drainage behavior has at least one upper side of the housing in an installed position according to an embodiment with respect to one Horizontal inclined outside walls. this will achieved in example by that a substantially cuboid Housing tilted against a horizontal held is attached. However, it can also be a cylindrical Housing be provided. Furthermore, it is possible a substantially cuboidal housing so align with an edge facing up. Furthermore is it cheap if the case as possible smooth surfaces and / or possibly none in one has acute angles meeting surfaces. Preferably, corresponding edges are rounded and have a Edge radius of at least 3 mm, preferably 5 mm, on. To avoid of dirt nests are preferably external hex screws, External tightening screws or general external polygonal screws used. These are preferably made of stainless steel and more preferably also like the motor housing with an inorganic, non-metallic coating provided.

The The invention further relates to a method for coating a Housing of an engine, of engine parts, engine attachments such as terminal box, connectors or the like, in particular an engine according to one of the above-described Embodiments, wherein at least on an outer side of the Housing at least one inorganic, non-metallic Coating, in particular one of the above described embodiments, is applied.

For the coating is preferably a coating process the group comprising sol-gel coating, chemical vapor deposition, plasma activated chemical vapor deposition and physical Gas phase coating used. The sol-gel coating can do this intended as a dipping, spraying or casting process be. Preferably, with a dipping method a simple simultaneous Coating the outside and inside of the case allows. By using suitable precursors The sol-gel coating can in particular metal oxide Connections according to the above list getting produced. Preferably, the sol-gel coating method becomes used for producing a silicon oxide layer.

At The site of a sol-gel process can also be a chemical vapor deposition, CVD, be used in a vacuum reactor by introducing suitable precursors on the located in the vacuum chamber Motor housing, in particular using temperature action For example, a metal oxide layer can be formed. A reduction a coating temperature is then advantageously possible when a plasma activated chemical vapor coating, PECVD, is used. Preferably, a coating temperature of less can be achieved as 100 ° C.

A Lowering the process temperature is also by means of a physical Gas phase coating, PVD possible, including, for example an electronic or thermal vapor deposition method or a sputtering method is used. A coating can be both by evaporation or sputtering of ceramic material as well reactive by evaporation or atomization of metallic Material can be produced in a reactive gas atmosphere.

When Procedure in the production of a generic Engine with a coating according to the invention is provided in a first variant that the housing is coated by a sol-gel process, the housing for Drying of the layer is baked, especially at a temperature of at least 200 ° C, and then the housing assembled to a motor. This is preferably a Temperature load on temperature-sensitive components of the engine, especially the magnet, avoided. To carry out The process is in a production of the engines in the Production line a sol-gel coating station with a subsequent Drying station provided.

Alternatively or additionally, it is provided that the housing is assembled into a motor and then coated, in particular by means of a particular plasma-activated chemical vapor deposition method, and / or by means of a physical vapor deposition method. Preferably, the application of a coating according to the invention makes it possible to manufacture without having to change a production process provided until the motor housing or the motor is assembled. Preferably, a coating temperature is less than 100 ° C, so that in particular the magnets in the case of an electric motor no Scha take that.

Farther the invention relates to the use of a motor with a housing, which at least on an outer side of an inorganic, non-metallic Coating, for food processing, food packaging, Drug processing, drug packaging, pharmaceutical processing, Pharmaceutical packaging, chemical processing or / and chemical packaging. For example, the motor is used to drive a stirrer, a transport device or the like. Used. Preferably exist even with direct contact of food with the housing no health impairments.

in the The invention will be explained by way of example with reference to the drawing. However, the drawing is not intended to be restrictive. Rather, in each case in the description and in the individual figures illustrated features for training within the scope of the claims combined with each other.

It demonstrate:

1 a schematic view of an engine,

2 a coating,

3 a scheme of a first procedure,

4 a scheme of a second procedure,

5 a motor with a connection box, and

6 an exploded view of a junction box.

The schematically illustrated engine 1 has a stainless steel case 2 which is used to attach the motor 1 on a plant or the like with a flange 3 is provided. In a fixed state, an output shaft 4 drive an unillustrated device. On an outside 5 of the housing 2 is an inorganic, non-metallic coating 6 applied, which is a ceramic layer, namely a glassy, as the main component silica-containing layer. To avoid standing drops of liquid is the housing 2 designed substantially cylindrical. Furthermore, in order to avoid standing liquid drops, which originate for example from a cleaning liquid, with rounded edges 7 Mistake.

The stainless steel case 2 encapsulates the inside of the case 2 located and not shown parts of the engine 1 both against dust and against liquid from. This is the flange 3 provided with a seal, not shown.

In addition - not shown - a terminal box, terminal box, plug or clamp connectors and / or a cable outlet may be provided, which is mounted on or on the housing. If available, this is like the housing 2 provided on at least one outside with an inorganic, non-metallic coating.

A coating according to the invention 6 is in 2 shown in a cross section. On a partially illustrated housing wall 8th , which consists for example of stainless steel, is an approximately 4 microns thick inorganic, non-metallic coating 6 applied, which is a silicon oxide layer. For improved adhesion can be between the housing wall 8th as well as in the coating 6 still be provided a primer layer. The coating 6 has a closed-pored, smooth surface 9 on. This prevents a liquid drop 10 an aggressive cleaning agent, which is chlorine-containing, acidic or alkaline, the housing wall 8th can attack.

The in 3 shown schematic procedure is provided for the assembly of an electric motor. In a first process step 11 a raw housing is provided. Without applying a coating method, this is an assembly of a motor supplied with the following process steps 12 and 13 , in which the required engine parts are used or a final assembly takes place. In the second process step 12 For example, the magnets of the motor are used.

For applying an inorganic, non-metallic coating at least on an outer side of the housing is in a fourth process step 14 , if necessary after prior cleaning of the housing, a sol-gel coating process is provided, which proceeds according to a spray process. Here, the raw housing is sprayed with a sol-gel solution and the resulting film is then dried in air. In the case of using a silicon oxide layer as an inorganic, non-metallic coating, for example, tetraethoxysilane, TEOS, dissolved in alcohol and reacted with water, used as a sol-gel solution. After the sol-gel coating in the fourth process step 14 the coated housing is in a fifth process step 15 a heat-up process supplied. Here, in the fourth step 14 dried coating and baked, so that a silicon oxide layer is formed. Depending on the adjusted viscosity of the sol-gel solution and the required layer thickness can fourth process step 14 and fifth process step 15 be run through several times before with the second step 12 the usual assembly procedure is continued again.

One Baking of the layer takes place for example at 200 ° C, preferably at 500 ° C. That's why it's generally not possible, the sol-gel coating after installation to provide the electromagnet in the housing.

A method for such a subsequent coating is in 4 shown. As in the in 3 The methods shown are a first, second or third method step 11 . 12 . 13 provided, which include the provision of the Rohgehäuses until the final assembly of the engine. Instead of a sol-gel coating process is in a sixth step 16 as a final step, a plasma-activated chemical vapor deposition method, PECVD provided. For this purpose, one or more motors are placed in a PECVD chamber and coated in a radio frequency or microwave frequency process. The precursor orgas is silane. The coating process requires no heating of the housing and allows a coating temperature of less than 100 ° C.

For other layer materials than silicon oxide are correspondingly different to use suitable precursors.

To achieve a sealed electrical connection, the in 5 shown engine 1 with a connection box 17 whose surface is like the surface of the engine 1 is provided with a non-metallic, inorganic coating. The coating of the connection box 17 can do it in one on the engine 1 assembled state. Preferably, however, the junction box is previously coated.

A previous coating also allows a coating in an interior of the 6 in an exploded view connection box 17 , As a result, for example, a corrosion by aggressive, especially chlorine-containing cleaning agent in case of partial failure of a seal 18 between lids 19 and junction boxes 20 inside the connection box or especially at the edges 21 . 22 of the connection housing 20 or the lid 19 be prevented. Likewise, this applies to the areas of the cable glands 23 , Advantageously, also the seal 18 be provided with a non-metallic inorganic coating according to the invention.

To reduce an attack surface against cleaning media become electrical energy connection 24 as well as in each case multi-pole control connections 25 . 26 . 27 Only two cable entries from the connection box 17 guided.

1

engine

2

stainless steel case

3

flange

4

output shaft

5

outside

6

coating

7

rounded edge

8th

housing wall

9

surface

10

liquid drops

11

first step

12

second step

13

third step

14

fourth step

15

fifth step

16

sixth step

17

junction

18

poetry

19

cover

20

Anschlussboxgehäuse

21

edge

22

edge

23

Grommet

24

electrical power connection

25-27

multipolar control connections

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited non-patent literature

• - ISO 4892 [0014]
• - IEC60529 [0020]

Claims (17)

Engine ( 1 ), in particular electric motor ( 1 ), with a housing ( 2 ), which at least on one outer side ( 5 ) an inorganic, non-metallic coating ( 6 ) having. Engine ( 1 ) according to claim 1, characterized in that the coating ( 6 ) at least one ceramic layer ( 6 ) having. Engine ( 1 ) according to claim 1 or 2, characterized in that a layer material is selected from the group comprising metal oxide, metal nitride, metal oxynitride, metal carbide, metal fluoride, metal sulfide and diamond-like carbon. Engine ( 1 ) according to one of the preceding claims, characterized in that the coating ( 6 ) Comprises silicon oxide, silicon nitride or silicon oxynitride as a main component. Engine ( 1 ) according to one of the preceding claims, characterized in that at least one adhesion-promoting layer below the coating ( 6 ) is provided. Engine ( 1 ) according to one of the preceding claims, characterized in that the coating ( 6 ) is at least substantially acid resistant and / or alkali resistant, especially in a pH range of about 2 to 12. Engine ( 1 ) according to one of the preceding claims, characterized in that a thickness of the coating ( 6 ) between 0.1 and 100 microns, in particular between 1 and 30 microns, and in particular between 3 and 10 microns. Engine ( 1 ) according to one of the preceding claims, characterized in that the coating ( 6 ) is hydrophobic. Engine ( 1 ) according to one of claims 1 to 7, characterized in that the coating ( 6 ) is hydrophilic. Engine ( 1 ) according to one of the preceding claims, characterized in that a tightness of the engine ( 1 ) meets protection class IP67 according to standard IEC 60529. Engine ( 1 ) according to one of the preceding claims, characterized in that the housing material is stainless steel or a light metal, preferably aluminum, is provided. Engine ( 1 ) according to one of the preceding claims, characterized in that the at least one upper side of the housing ( 2 ) in an installed position with respect to a horizontal inclined outer walls ( 8th ) having. Method for coating a housing of an engine ( 1 ), wherein at least on one outer side ( 5 ) of the housing ( 2 ) at least one inorganic, non-metallic coating ( 6 ) is applied. Method according to claim 13, characterized in that a coating process from the group comprising sol-gel coating, chemical vapor deposition, plasma activated chemical vapor deposition and physical vapor deposition is used. Method according to claim 14, characterized in that the housing ( 2 ) is coated by means of a sol-gel process, the housing ( 2 ) is dried to dry the layer, in particular at a temperature of at least 200 ° C, and then the housing ( 2 ) to a motor ( 1 ) is assembled. Method according to one of claims 12 to 15, characterized in that the housing ( 2 ) to a motor ( 1 ) and subsequently coated, in particular by means of a particularly plasma-activated chemical vapor deposition method, or / and by means of a physical vapor-phase coating method. Using an engine ( 1 ) with a housing ( 2 ), which at least on one outer side ( 5 ) an inorganic, non-metallic coating ( 6 ), for food processing, food packaging, drug processing, drug packaging, pharmaceutical processing, pharmaceutical packaging, chemicals processing and / or chemical packaging.