Configuration of an output side of a dynamo-electric machine for use in sterile process engineering

Abstract

The invention relates to a configuration of an output side (A-side) of a dynamo-electric machine (1) for use in sterile process engineering, in particular in the food industry, comprising at least one dynamo-electric machine (1) and at least one output element driven by a shaft (5) of the dynamo-electric machine (1) on the A-side of the dynamo-electric machine (1), wherein the shaft (5) rotates about an axis (15) and is supported in bearings (12), wherein the A-side of the dynamo-electric machine (1) comprises at least a bearing flange (13) and a transition flange (2) fastened thereto, which are connected to one another by screw connections in an installation space located close to the axis, wherein the installation space (16) is sealed by means of a sleeve (7) and a shaft seal (10), or solely by means a shaft seal (10), wherein a mounting flange (3) is connected to the transition flange (2) by screw connections, wherein the screw heads (8) of these screw connections face towards the dynamo-electric machine (1), wherein the output element is coupled to the end region of the shaft (5) on the A-side of the dynamo-electric machine (1).

Description

[0001] Description

[0002] Design of an output side of a dynamoelectric machine in sterile process engineering

[0003] The invention relates to a design of an output side of a dynamoelectric machine in sterile process engineering, particularly in the food industry.

[0004] In sterile process engineering, particularly in the food industry, international and national regulatory authorities have developed standards, including those for the design of the equipment used. Examples include the standards of the American Society of Mechanical Engineers (ASME), especially the ASME Bioprocessing Equipment Standard (BPE), the 3-A Sanitary Standards Incorporation (3-A), and the European Hygienic Design Group (EHEDG). The ASME, BPE, and 3A standards are particularly relevant in the United States, while the EHEDG standard is primarily relevant in Europe. Typical requirements for a component, as defined by at least one of these hygiene regulations, relate specifically to the geometry and / or surface of the component, which should be designed to prevent deposits from forming and to facilitate easy cleaning and / or sterilization.The EHEDG standard, for example, also excludes sharp-edged transitions. Therefore, for instance, the angle between two adjacent surfaces should be greater than 135 degrees, and / or the radius at the transition between two surfaces should be greater than 3.2 mm. Furthermore, a surface roughness of less than 0.78 micrometers is required.

[0005] The EHEDG understands cleanability as a prerequisite for the disinfection of components or systems to prevent the proliferation of microorganisms, contamination by foreign bodies, or the ingress and infestation of pests. For production facilities that are difficult to clean, this can lead to more complex cleaning and decontamination processes, resulting in higher costs. Consequently, longer downtimes and / or the use of more aggressive, and therefore more environmentally harmful, chemical cleaning agents are likely.

[0006] All surfaces that come into direct or indirect contact with food must therefore be easy to clean. Various geometric and surface characteristics play a crucial role in the cleanability of these surfaces. For example, rough surfaces should be avoided, as they increase cleaning time. Product residue can become trapped in surface irregularities. Seals must be designed so that no product or dirt residue can get stuck in crevices. Exposed fasteners, such as screw threads, hinges, metal-to-metal connections, etc., should also be avoided.

[0007] Furthermore, all internal angles of 135° or less should have a minimum radius of 3 mm, and sharp corners should be avoided. Another criterion is the automatic emptying of devices, e.g., bags, which can be ensured by surfaces with a minimum sloping angle of 3°.

[0008] The EHEDG lists, among other things, the following properties that the material used must possess when used as intended:

[0009] The material used should be inert to the product and to cleaning and disinfecting agents. Furthermore, it should be corrosion-resistant, non-toxic, non-stick, and mechanically stable.

[0010] In addition to elastomers, adhesives and sealants, lubricants, signal transmission fluids, and thermal insulation materials, the EHEDG also lists plastics as a possible, and in some cases superior, alternative to stainless steel. Plastic components are particularly suitable for applications requiring lower weight, higher wear resistance, or greater chemical resistance than stainless steel.

[0011] Of course, food-grade plastics are also subject to strict legal requirements, including EU Regulation 10 / 2011 and FDA regulations. The criteria for food contact with plastics range from temperature resistance and cleanability to hydrophobicity. Hydrophobicity describes the water-repellent properties of surfaces.

[0012] Especially in the food and beverage sector, there is currently no technical solution for an EHEDG (European Hygienic Engineering and Design Group) compliant seal for a motor or gearbox flange. These EHEDG requirements are not currently met, particularly for the seal between a drive shaft and, for example, a pulley – i.e., on the A-side of a motor or gearbox. This means that no food product may come into contact with this motor A-side or the shaft exit, as these output elements or attachments, such as pulleys, cannot be properly cleaned. Furthermore, threads – with or without threaded inserts – are particularly difficult to clean and therefore unsuitable or even prohibited for use in the food industry.

[0013] The output side of a dynamo-electric machine, such as a motor, must not come into contact with the food, as components like a shaft and any customer-specific attachments cannot be cleaned in accordance with EHEDG regulations. Therefore, until now, the output side of the motor, i.e., the A-side of the motor, had to have an EHEDG-compliant gearbox or coupling to meet these requirements.

[0014] This coupling lantern covers the components that cannot be cleaned according to EHEDG standards. This coupling lantern must also be made of stainless steel, e.g., 1.4404, and must not exceed a surface roughness of Ra 0.8. This, in turn, makes such a seal expensive. Furthermore, such a mounting on the A-side of the motor occupies a comparatively large axial installation space, which limits the design options for the output side.

[0015] Based on this, the invention aims to design a drive side of a dynamoelectric machine in sterile process engineering, particularly in the food industry, in such a way that it is EHEDG-compliant and does not restrict the design possibilities of the drive side.

[0016] The problem can be solved by the characteristics of independent claims.

[0017] Advantageous configurations can be found in the dependent claims and / or the description.

[0018] In a dynamo-electric machine, such as a motor, there is an A-side (output side), one end of which faces shaft components such as output elements and / or a driven machine and is mechanically coupled to this driven machine. The B-side of the motor is located at the other end of the shaft and faces away from the shaft components.

[0019] According to the invention, the A-side output element of the motor is understood to be a pulley, a clutch, or a gear. The driven machine is, for example, a pump or a compressor. According to the invention, the output side of the dynamo-electric machine is designed such that EHEDG-compliant flat gaskets, e.g., made of silicone or EPDM, seal all relevant contact surfaces. Furthermore, the shaft bore located on the A-side is sealed with an EHEDG-compliant stainless steel screw and a stainless steel washer. The EHEDG shaft seal made of PTFE runs on a stainless steel sleeve, e.g., made of 1.4404, with a roughness of < R a 0.8.

[0020] The EPDM seals used according to the invention are made of ethylene-propylene-diene rubber (ethylene-propylene-diene; M group) with terpolymers of ethylene, propylene and an unspecified diene.

[0021] These EPDM seals exhibit comparatively good chemical resistance in contact with water / water vapor, cooling liquids, acids and alkalis.

[0022] In general, EPDM is resistant to long-term aging, UV radiation and ozone, weather-resistant, robust, walkable, thermally resistant and frost-proof, as well as easy and fire-safe to process in building areas.

[0023] EPDM is known to be a material that has a minimal environmental impact during its manufacture, processing, and use. It contains no volatile plasticizers or pollutants that can be released over its service life. The material can be recycled and used, for example, for floor coverings or even incinerated.

[0024] The mounting flange, particularly the customer-side one, is designed to facilitate easy cleaning of the motor flange surfaces and shaft attachments. This design incorporates the largest possible chamfers and radii on the mounting flange.

[0025] A chamfer is generally understood to be a narrow surface created on a workpiece by chamfering (also called beveling or chamfering), replacing the edge. Sharp edges with small radii are thus avoided.

[0026] Furthermore, the holes in the flanges for the mounting bolts are designed as blind holes, specifically with axial alignment. The motor is sealed with the included flat gaskets.

[0027] Due to its intended use, the pulley is also made of a material approved by the EHEDG (for example, stainless steel 1.4404). According to the invention, the output side of the motor – i.e., the A-side – can thus be implemented in a comparatively compact and cost-effective manner, requiring significantly less installation space, especially axially. This enables, for example, a direct and space-saving drive system for a machine such as a pump, compressor, etc., in the food industry, the pharmaceutical industry, and medical technology, using a pulley.

[0028] The invention and further advantageous embodiments of the invention can be seen in the exemplary embodiment shown in principle, which shows:

[0029] FIG 1 shows a principal longitudinal section of an A-side of an engine,

[0030] FIG 2 shows a perspective view of the longitudinal section of the A-side of the engine,

[0031] FIG 3 shows a basic longitudinal section of a further embodiment of an A-side of a motor,

[0032] FIG 4 shows a perspective view of the longitudinal section of this design of the A-side of the engine,

[0033] FIG 5 shows an EHEDG-compliant bolted joint.

[0034] It should be noted that terms such as "axial," "radial," "tangential," etc., refer to the axis used in the respective figure or described example. In other words, the directions axial, radial, and tangential always refer to an axis of a motor 1 and thus to the corresponding axis of symmetry of the stator. "Axial" describes a direction parallel to the axis, "radial" describes a direction orthogonal to the axis, either towards or away from it, and "tangential" is a direction that is circular around the axis at a constant radial distance and with a constant axial position. The expression "circumferential" or "circumferential" is synonymous with "tangential."

[0035] With regard to a surface, e.g. a cross-sectional area, the terms "axial", "radial", "tangential", etc. describe the orientation of the normal vector of the surface, i.e. the vector that is perpendicular to the surface in question.

[0036] The term "coaxial components," e.g., coaxial components such as the rotor and stator of motor 1, refers here to components that have the same normal vectors, meaning that the planes defined by the coaxial components are parallel to each other. Furthermore, the term implies that the centers of coaxial components lie on the same axis of rotation or symmetry. However, these centers may be located at different axial positions on this axis 15, and the aforementioned planes may therefore have a distance greater than zero from each other. The term does not necessarily require that coaxial components have the same radius.

[0037] The term "complementary," in the context of two components that are complementary to each other, means that their external forms are designed such that one component can preferably be completely enclosed within its complementary component, so that the inner surface of one component and the outer surface of the other ideally touch seamlessly, without any gaps. Consequently, in the case of two complementary objects, the external form of one object is determined by the external form of the other. The term "complementary" could be replaced by the term "inverse."

[0038] For the sake of clarity, in some cases where components are present multiple times, not all components shown in the figures are provided with reference symbols.

[0039] The figures show basic embodiments of the invention, whereby, among other things, the radii shown in the drawings are therefore not always depicted in accordance with EDHG.

[0040] The described embodiments can be combined in any way desired. Likewise, individual features of the respective embodiments can also be combined without departing from the essence of the invention.

[0041] FIG. 1 shows a longitudinal section of an output side (A-side) of a dynamoelectric machine, in particular a motor 1. In a dynamoelectric machine, such as a motor 1, there is an A-side, one shaft end of which faces output elements and / or a driven machine (generally shaft attachments) and is mechanically coupled to these directly or indirectly. The B-side of the motor is located at the other shaft end and faces away from the driven machine. The dynamoelectric machine is designed as a synchronous or asynchronous machine. A bearing flange 13 is provided on the output side of the dynamoelectric machine, which has bearings 12 to support a shaft 5. The bearing flange 13 is at least partially surrounded by a transition flange 2, to which it is connected by axially parallel connecting bolts. This connection is provided in a specially designed axially recessed section – a mounting space 16 – of the transition flange 2.This axially recessed section is sealed by means of a sleeve attached to the shaft side, in particular a stainless steel sleeve 7 and a complementary shaft seal 10, in particular EHEDG-compliant.

[0042] The transition flange 2 and bearing flange 13 can also be made in one piece.

[0043] A mounting flange 3 is axially connected to the transition flange 2 and is linked to it via screw connections. These screw connections, especially their screw heads 8, are accessible via a circumferential recess 18 in the transition flange 2.

[0044] The mounting flange 3 can also be at least part of a customer-supplied machine.

[0045] The mounting flange 3 has an internal bore, in particular the side facing away from the motor 1 is chamfered to provide, among other things, additional axial installation space.

[0046] This mounting flange 3, particularly the customer-side one, is designed according to the invention such that cleaning of the flange surfaces (on the side facing away from the motor 1) and / or the shaft mounting elements is easily possible. Therefore, the mounting flange 3 is designed with the largest possible chamfer 17 and the largest possible radii.

[0047] According to the invention, the A-side shaft mounting element of the motor 1 is understood to be a pulley 6, a clutch and / or a working machine, e.g. a pump or compressor.

[0048] In this context, chamfer 17 is generally understood to be a narrow surface created on a workpiece by chamfering (also called beveling or chamfering), instead of an edge. Sharp edges with small radii are thus avoided.

[0049] Figures 1 and 2, shown in perspective, further illustrate a seal on a pulley 6 as a shaft mounting element. The EHEDG-compliant flat gaskets 4, made of materials such as silicone or EPDM, seal the contact surfaces. Furthermore, the shaft bore or shaft face 14 is sealed with an EHEDG-compliant stainless steel screw 9, a gasket 4, and a stainless steel washer 11.

[0050] The EHEDG shaft seal 10 made of PTFE (polytetrafluoroethylene) runs on the stainless steel sleeve 7, e.g., made of 1.4404 with a roughness of < R a 0.8.

[0051] In a further embodiment of the invention according to FIGS. 3 and 4, the EHEDG shaft seal 10 runs directly on the shaft 5. Therefore, a stainless steel sleeve 7 is not necessary. However, in order to design the output side of the motor 1 in accordance with EHEDG standards, a shaft shoulder 22 is provided, which is designed as a reduction of the shaft diameter. This shoulder is sealed – as can be seen in FIGS. 3 and 4 – against an output element, for example a pulley 6, by a seal 4. This shaft shoulder 22, for receiving a seal 4, is axially spaced from the shaft seal 10 and is provided between the shaft seal 10 and an output element.

[0052] FIG 5 shows EHEDG-compliant stainless steel screws 9, with a screw head extension 20 and a suitable screw seal 21, as they are to be used on relevant connections.

[0053] In further embodiments, the transition flange 2 and bearing flange 13 can also be manufactured as a single piece, forming a motor flange to which the customer-supplied mounting flange 3 can be attached via the screw connections shown in FIG. 5. Screw connections between the transition flange 2 and bearing flange 13 would then be eliminated.

[0054] The seals 4, in particular flat seals, are preferably designed as EPDM seals and are made of ethylene propylene diene rubber (ethylene propylene diene; / W group) with terpolymers of ethylene, propylene and an unspecified diene.

[0055] EPDM seals are also used as O-rings in contact with water / steam, coolants, acids and alkalis due to their good chemical resistance.

[0056] EPDM is resistant to long-term aging, UV radiation, and ozone, as well as being weather-resistant, robust, walkable, thermally stable, and frost-proof. It is also easy to work with and fire-safe in building applications. EPDM is considered a material that has a minimal environmental impact during its production, processing, and use. It contains no volatile plasticizers or pollutants that can be released over its service life. The material can be recycled and used, for example, for floor coverings or even incinerated.

[0057] Furthermore, the holes for the mounting screws of motor 1 and / or the mounting flange 3 must be designed as blind holes. Motor 1 is further sealed with flat gaskets 4.

[0058] Preferably the axes 19 of the screw connections between mounting flange 3 and transition flange 2 and / or between bearing flange 13 and transition flange 2 are aligned parallel to the axis 15, which simplifies, among other things, the assembly of this arrangement.

[0059] Pulley 6 is also made of a material approved by the EHEDG, for example, stainless steel 1.4404 (X2CrNiMo17-12-2). This is an austenitic, rust-resistant steel. Due to its lower carbon content, it is easier to machine than the otherwise equivalent stainless steel 1.4401.

[0060] The mounting of working machines on the output side of the motor 1, especially in food technology, is thus more compact and versatile, because working machines can now be driven with a pulley 6 and / or via a clutch and / or via a gear or directly.

[0061] This results in a greater variety of drive systems within a comparatively small installation space.

[0062] Previously, this output side had to be covered by a complex coupling lantern. This meant that this coupling lantern also had to be made of stainless steel, e.g., 1.4404, and could not exceed a surface roughness of Ra 0.8. Furthermore, such a mounting required a relatively large amount of axial installation space. This complex design increased the cost of such applications in the food industry.

[0063] According to the invention, the output side of the motor 1 can thus be implemented more compactly and cost-effectively, occupying significantly less installation space, especially axially. This makes it possible, for example, to drive a machine such as a pump, compressor, etc., directly and in a space-saving manner, even in the food industry, via a pulley 6. This inventive design of the output side of the motor 1 now allows, for example, a pulley 6 or a gear to be installed in a compact and simple manner in compliance with EHEDG.

[0064] Reference symbol list

[0065] 1 engine

[0066] 2 transition flanges

[0067] 3 Mounting flange

[0068] 4 Seal

[0069] 5 wave

[0070] 6 Pulley

[0071] 7 stainless steel sleeve

[0072] 8 screw heads

[0073] 9 stainless steel screws

[0074] 10 Shaft seal

[0075] 11 stainless steel discs

[0076] 12 warehouses

[0077] 13 Bearing flange

[0078] 14 wave mirrors

[0079] 15 axle

[0080] 16 construction space

[0081] 17th phase

[0082] 18 Exclusion

[0083] 19 axes of the bolted connections

[0084] 20 Screw head extension

[0085] 21 Screw seal

[0086] 22 wave step

Claims

Patent claims 1. Design of an output side (A-side) of a dynamoelectric machine (1) in sterile process engineering, in particular in the food industry, comprising at least one dynamoelectric machine (1) and at least one output element driven via a shaft (5) of the dynamoelectric machine (1) on the A-side of the dynamoelectric machine (1), wherein the shaft (5) rotates about an axis (15) and is held in bearings (12), wherein the A-side of the dynamoelectric machine (1) has at least one bearing flange (13) and a transition flange (2) attached thereto, which are connected in an installation space near the axis by means of screw connections, wherein the installation space (16) is designed as an axially recessed section and is closed at least by means of a sleeve (7) and a shaft seal (10), wherein an attachment flange (3) is connected to the transition flange (2) by means of screw connections.wherein the screw heads (8) of these screw connections point towards the dynamoelectric machine (1), wherein the output element is coupled to the end region of the shaft (5) on the A-side of the dynamoelectric machine (1), wherein at least the seals provided on the output side (A-side), such as flat gaskets (4), are designed in accordance with EHEDG.

2. Design of an output side (A-side) of a dynamoelectric machine (1) in sterile process engineering, in particular in the food industry, comprising at least one dynamoelectric machine (1) and at least one output element driven via a shaft (5) of the dynamoelectric machine (1) on the A-side of the dynamoelectric machine (1), wherein the shaft (5) rotates about an axis (15) and is held in bearings (12), wherein the A-side of the dynamoelectric machine (1) has at least one bearing flange (13) and a transition flange (2) attached thereto, which are connected in a space near the axis by means of screw connections, wherein the space (16) is closed by means of a shaft seal (10), wherein an attachment flange (3) is connected to the transition flange (2) by means of screw connections, wherein the screw heads (8) of these screw connections face the dynamoelectric machine (1),wherein the output element is coupled to the end region of the shaft (5) on the A-side of the dynamo-electric machine (1) and serves as a drive adapter, such as a pulley (6) or a, a coupling or a gear is formed and drives at least one working machine, wherein at least the seals provided on the output side (A-side), such as flat gaskets (4), are designed in accordance with EHEDG.

3. Design of an output side (A-side) of a dynamoelectric machine according to claim 1 or 2, characterized in that the bearing flange (13) and transition flange (2) are made in one piece.

4. Design of an output side (A-side) of a dynamoelectric machine according to one of claims 1 to 3, characterized in that the mounting flange (3), in particular on the side facing away from the dynamoelectric machine (1), has comparatively large radii and / or comparatively large chamfers (17).

5. Design of an output side (A-side) of a dynamoelectric machine (1) according to one of claims 1 to 4, characterized in that a working machine is directly coupled to the shaft (5) on the output side (A-side) of the dynamoelectric machine.

6. Design of an output side (A-side) of a dynamoelectric machine (1) according to one of the preceding claims, characterized in that the axes of the screw connections between bearing flange (13) and transition flange (2) and / or mounting flange (3) and transition flange (2) run parallel to the axis.

7. Design of an output side (A-side) of a dynamoelectric machine (1) according to one of the preceding claims, characterized in that the output element is held at the end region of the shaft (5) by means of a screw, a stainless steel disc and a flat seal (4) on the shaft face (14).

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