ELECTRIC MOTOR IN STAINLESS STEEL VERSION

Abstract

An electric motor (1) made of stainless steel with improved heat dissipation is disclosed. For this purpose, a sleeve (10) is provided, which extends in the direction of an axis (A) of a shaft (5) of a rotor (4) and is in thermally conductive contact with a stator (2) and a flange (8) on the rotor (4). The sleeve (10) is covered along its entire length in the direction of the axis (A) by an outer sleeve (14). The sleeve (10) itself is made of a material that has a higher thermal conductivity than the outer sleeve (14).

Description

[0001] The invention relates to an electric motor made of stainless steel. In particular, the electric motor in stainless steel comprises a rotor with a stainless steel shaft, which is supported in a flange and a bearing shield opposite the axis. A stator surrounds the rotor. An outer sleeve connects at a first end to the flange and at a second end opposite the axis to the bearing shield. Background of the invention, state of the art

[0002] US Patent 11,382,246 B2 discloses a tubular linear motor comprising a stator, a rotor, and a base flange. The stator is in thermal contact with the base flange. The stator is enclosed in a liquid-tight stainless steel casing. The base flange is made at least partially of a material with a higher thermal conductivity than stainless steel. The stator, together with the base flange, is enclosed by a stainless steel casing that is in thermal contact with the base flange and encloses both the base flange and the stator.

[0003] Chinese utility model CN ​​2 03 014 594 U discloses a motor structure with good heat dissipation. The structure comprises a drive motor. A rear end of the drive motor is connected to a heat dissipation motor. A front end of the heat dissipation motor is provided with an output shaft. The output shaft is connected to a fan located within the heat dissipation motor.

[0004] Chinese patent application CN 1 04 410 197 A relates to a stainless steel motor housing structure. The stainless steel motor housing structure comprises a stainless steel housing in which a lining made of a thermally conductive material is arranged and a stator is mounted within the lining. The lining is installed in the housing, and the motor stator is mounted within the lining.

[0005] Chinese utility model CN ​​2 15 601 134 U relates to the technical field of stainless steel castings and discloses a stainless steel casting with good heat dissipation performance. The upper end of the engine cover is firmly connected to the lower end of a round tube. A cover plate is arranged at the upper end of the round tube, with the lower end of the cover plate connected to the upper end of the round tube by a clamping ring. The sealing performance between a heat-absorbing copper sheet and an installation groove can be ensured by a sealant.

[0006] German patent application DE 10 2022 000 507 A1 discloses an electric motor whose stator is housed in an aluminum tube. A seal, in particular an O-ring, is arranged between the tube and the bearing flange. Specifically, the tube section has a circumferentially continuous annular groove on its radial outer surface, in which the seal is received and thus axially positionable. Another seal, in particular an O-ring, is arranged between the tube and the housing section. This additional seal is also pushed onto the tube section.

[0007] German patent application DE 10 2014 001 267 A1 discloses an electric motor with a housing in which an inner and an outer layer consist of different materials. The inner layer consists of a light metal or a metal alloy with a thermal conductivity greater than 100 W / (m·K). The outer layer, on the surface of the housing, consists of stainless steel or an alloyed stainless steel. A concealed ring seal closes the gap between the outer and inner layers. Brief description of the invention

[0008] The object of the invention is to provide an electric motor in stainless steel design that meets the high demands for cleanliness, hygiene and corrosion protection and provides improved heat dissipation.

[0009] This problem is solved by an electric motor in stainless steel design which comprises the features of claim 1.

[0010] In one embodiment, the stainless steel electric motor comprises a rotor with a stainless steel shaft. The shaft is supported in a flange that extends transversely to an axis of the shaft and in a bearing shield that extends along the axis and is located opposite the shaft. A stator surrounds the rotor. An outer sleeve connects at one end to the flange and at a second end opposite the axis to the bearing shield.

[0011] A sleeve extends along the axis of the electric motor. This sleeve is in thermally conductive contact with the stator and the flange and is covered or encased by the outer sleeve along its entire length in the direction of the axis. The sleeve is made of a material with a higher thermal conductivity than the material of the outer sleeve.

[0012] A first circumferential seal with an L-shaped cross-section is provided. The first end of the outer sleeve, the sleeve itself, and the flange seal against this first circumferential seal. A second circumferential seal, also with an L-shaped cross-section, seals against the first end of the bearing shield and the outer sleeve. A third circumferential seal also has an L-shaped cross-section. The second end of the bearing shield and a cap seal against this third seal.

[0013] The inventive design of the electric motor has the advantage that such a sleeve ensures improved heat dissipation while maintaining the high demands on cleanliness, hygiene, cleaning and corrosion protection.

[0014] Preferably, the outer sleeve is made of stainless steel that meets hygienic requirements. The sleeve is preferably made of aluminum. The sleeve can also be made of another material, provided that the sleeve material has a higher thermal conductivity than the stainless steel outer sleeve. The sleeve material can, for example, be an aluminum alloy, copper, or a copper alloy. The advantage is that heat dissipation to the flange (output-side end shield) is improved when the aluminum sleeve is mounted between the coil and the stainless steel outer housing components.

[0015] In one embodiment, a cap mounted on the end shield seals the electric motor. All externally facing components, such as the flange, outer sleeve, end shield, cap, and shaft, are preferably made of stainless steel. Stainless steel types such as X2CrNiMo17-12-2 (material no. 1.4404) or other V2 and V4 steels can be used. The hygienic design of the external components complies with DIN EN 1672-2. The material selection for components that may come into contact with food complies with DIN 10528.

[0016] In one embodiment, the flange and outer sleeve, the outer sleeve and the bearing shield, and the bearing shield and the cap are each connected by a seal (sealing ring). The seal material also meets very high standards of cleanliness and hygiene, making it suitable for use in the chemical and pharmaceutical industries, as well as in areas requiring special cleaning or disinfection. The seal material can be, for example, a silicone seal or another food-grade seal compliant with FDA and EU1935 / 2004.

[0017] Stainless steel motors are particularly suitable for use in the food, beverage and medical industries, as well as in industries with very high demands on cleanliness, hygiene and corrosion protection.

[0018] Furthermore, these stainless steel motors are ideally suited for use in the chemical and pharmaceutical industries, as well as in areas requiring special cleaning or disinfection. The hygienic design of the external components complies with DIN EN 1672-2. The material selection for components of the electric motor that may come into contact with food complies with DIN 10528. Likewise, the lubricant used in the bearings (ball bearings) of the electric motor complies with DIN EN ISO 21469. The sealing concept and the seals used achieve IP69 / IP69K protection for the entire electric motor.

[0019] The invention and its advantages will now be explained in more detail with reference to the accompanying drawings, using exemplary embodiments, without thereby limiting the invention to the embodiment shown. The proportions in the figures do not always correspond to the actual proportions, as some shapes are simplified and others are enlarged in relation to other elements for better illustration. Brief description of the drawings Fig. Figure 1 shows a perspective sectional view of an embodiment of the electric motor according to the invention in partial section, which illustrates the structure of the electric motor. Fig. Figure 2 shows a sectional view of the embodiment of the electric motor according to the invention. Fig. 1. Fig. Figure 3 shows an enlarged view of the in Fig. 2. Area of ​​the connection between flange and outer sleeve marked with a dashed rectangle. Fig. Figure 4 shows an enlarged view of the in Fig. 2. Area of ​​the connection between outer sleeve and bearing shield marked with a dashed rectangle. Fig. Figure 5 shows an enlarged view of the image in Fig. 2. Area of ​​the connection between the bearing shield and the cap marked with a dashed rectangle. Detailed description of the invention with reference to the drawings

[0020] Identical reference numerals are used for identical or equivalently functioning elements of the invention. Furthermore, for the sake of clarity, only those reference numerals necessary for describing the respective figure are shown in the individual figures. The figures merely illustrate embodiments of the invention, without, however, limiting the invention to the illustrated embodiments.

[0021] Fig. Figure 1 shows a perspective sectional view along a shaft 5 of an embodiment of the electric motor 1 according to the invention, all of whose externally facing components are made of stainless steel. The shaft 5 of the electric motor 1 is rotatably mounted by means of two bearings 7. The shaft 5 is part of a rotor 4 and carries permanent magnets 6. The rotor 4 is surrounded by a stator 2, which carries several coils 3. The stator 2 is radially surrounded on the outside by an outer sleeve 14. A flange 8 is located at one end of the outer sleeve 14, and a bearing shield 12 is connected to the opposite end of the outer sleeve 14. The bearing shield 12 is closed with a cap 9.The outer components, made of stainless steel, such as flange 8, outer sleeve 14, bearing shield 12, and cap 9, are connected in such a way that no dirt and / or moisture can penetrate the electric motor 1 from the outside, nor can dirt escape from the inside of the electric motor 1. The outer sleeve 14 and the bearing shield 12 are dimensioned in their outer diameters such that, when the electric motor 1 is assembled, the tube has a uniform outer diameter.

[0022] The external design of the electric motor 1 described here serves only to describe one possible embodiment and should not be interpreted as a limitation of the invention.

[0023] Fig. Figure 2 shows a sectional view of the embodiment of the electric motor 1 according to the invention. Fig. 1. The external components of the electric motor 1 are made of stainless steel. These components are: the shaft 5, the flange 8, which carries a bearing 7, the outer sleeve 14, the end shield 12, which carries another bearing 7, and the cap 9. A bearing seal 18 is provided between the shaft 5 and the flange 8 at a through-hole 11 in the shaft 5. The outer sleeve 14 is connected to the flange 8 via a circumferential seal 16. At the other end of the outer sleeve 14, another circumferential seal 16 is provided between the outer sleeve 14 and the end shield 12. A further circumferential seal 16 is provided between the end shield 12 and the cap 9. The end shield 12 also has a feed opening 13 through which at least one cable or connector (not shown) can be supplied for the power connection of the electric motor 1.

[0024] A sleeve 10 is in thermal contact with the stator 2 and the flange 8, the sleeve 10 being covered externally by the outer sleeve 14. The sleeve 10 has a higher thermal conductivity than stainless steel. Preferably, the sleeve 10 is made of aluminum, which cannot be considered a limitation of the invention.

[0025] Fig. Figure 3 shows an enlarged view of the in Fig. 2. Area 20 is marked with a dashed rectangle. The aluminum sleeve 10 is in direct thermal contact with the flange 8. The stainless steel outer sleeve 14 surrounds the aluminum sleeve 10, thus providing complete shielding of the aluminum of the sleeve 10 from the outside. The circumferential (first) seal 16 (sealing ring) ensures a tight connection, so that it rests against the outer sleeve 14, the flange 8, and the sleeve 10. Preferably, the circumferential seal 16 has an L-shaped cross-section. Thus, the circumferential seal 16 rests against a first end 141 of the outer sleeve 14, the sleeve 10, and the flange 8.

[0026] Fig. Figure 4 shows an enlarged view of the in Fig. 2. The area marked with a dashed rectangle 30 illustrates the connection between the outer sleeve 14 and the bearing shield 12. According to the possible embodiment shown here, the bearing shield 12 overlaps the outer sleeve 14 at its second end 142. The second end 142 of the outer sleeve 14 rests against the bearing shield 12. A first end 121 of the bearing shield 12 rests against the L-shaped (second) seal 16 (sealing ring), which also rests against the outer sleeve 14.

[0027] Fig. Figure 5 shows an enlarged view of the image in Fig. 2. The area marked with a dashed rectangle 40 illustrates the connection between the bearing shield 12 and the cap 9. According to one possible embodiment, a second end 122 of the bearing shield 12 receives the (third) seal 16 (sealing ring). The cap 9 seals against the seal 16.

[0028] It is assumed that the present disclosure and many of the advantages mentioned therein will be understood from the preceding description. It is obvious that various modifications in the shape, construction, and arrangement of the components can be made without departing from the disclosed subject matter. The described form is merely explanatory, and it is the intention of the appended claims to encompass and include such modifications. Accordingly, the scope of the invention should be limited only by the appended claims. Reference symbol list 1 electric motor 2 Stator 3 coil 4 Rotor 5 wave 6 permanent magnets 7 warehouses 8 flange 9 cap 10 sleeve 11 Implementation, 12 Storage sign 121 first end warehouse sign 122 second end warehouse sign 13 Inlet opening 14 Outer sleeve 141 first end outer sleeve 142 second end outer sleeve 16 Seal 18 Bearing seal 20 area, rectangle 30 area, rectangle 40 area, rectangle Axis

Claims

[1] An electric motor (1) in stainless steel comprising: a rotor (4) with a shaft (5) made of stainless steel, which is supported in a flange (8) and a bearing shield (12) opposite in the direction of an axis (A), a stator (2) surrounding the rotor (4), an outer sleeve (14) which connects at a first end (141) to the flange (8) and at a second end (142) opposite in the direction of the axis (A) to the bearing shield (12), a sleeve (10) extending in the direction of the axis (A) and in thermally conductive contact with the stator (2) and the flange (8) and covered by the outer sleeve (14) over its entire length in the direction of the axis (A), wherein the sleeve (10) is made of a material that has a higher thermal conductivity than the outer sleeve (14), characterized by a first circumferential seal (16) with an L-shaped cross-section, against which the first end (141) of the outer sleeve (14), the sleeve (10) and the flange (8) abut in a sealing manner; a second circumferential seal (16) with an L-shaped cross-section; against which a first end (121) of the bearing shield (12) and the outer sleeve (14) abut in a sealing manner; and a third circumferential seal (16) with an L-shaped cross-section, to which a second end (122) of the bearing shield (12) and a cap (9) abut in a sealing manner. [2] The electric motor (1) according to claim 1, wherein the sleeve (10) is made of aluminium, an aluminium alloy, copper or a copper alloy. [3] The electric motor (1) according to one of the preceding claims, wherein the cap (9) closes off the bearing shield (12) to the outside. [4] The electric motor (1) according to one of the preceding claims, wherein the flange (8), the outer sleeve (14), the bearing shield (12) and the cap (9) are made of stainless steel. [5] The electric motor (1) according to claim 1, wherein all outwardly facing components, such as the flange (9), the outer sleeve (14), the bearing shield (12), the cap (9) and also the shaft (5) comply with DIN EN 1672-2 and components that come into contact with food comply with DIN 10528. [6] The electric motor (1) according to claim 1, wherein the seal (16) is a silicone seal or, for food-grade applications, an FDA & EU1935 / 2004 compliant seal (16).

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