DE202018002207U1 - motor rotor - Google Patents

Abstract

Motor rotor (10) with:
a magnetic carrier (20);
a magnet (40) carried by the magnet carrier (20);
a sleeve (60) enclosing the magnet (40); and
a first and a second circumferential seal (50, 52) arranged to seal the magnet (40) within a space between the magnet carrier (20) and the sleeve (60).

Description

The present invention relates to a motor rotor.

Engines are known. In an electric motor, a rotor assembly is provided which revolves with respect to a non-rotating part or stator. In one embodiment of a motor, the stator includes one or more coils surrounding the rotor assembly having one or more magnets. The excitation of the coils causes the circulation of the rotor assembly within the stator.

Although engines are useful, their operation can have unexpected consequences. Accordingly, it is desirable to provide an improved rotor.

According to a first aspect, there is provided a motor rotor comprising: a magnet carrier, a magnet held by the magnet carrier, a sleeve surrounding the magnet, first and second circumferential seals arranged to sandwich the magnet within a void space between the magnet carrier and the sleeve seals. This first aspect takes into account that when operating an engine in a difficult environment such as occurs when a motor is operated in an aggressive chemical environment where environmental chemicals can attack the engine or degrade its performance, it may be desirable to: To complete the magnet against this environment to maintain its performance.

Accordingly, a runner is provided. The rotor may be provided for an electric motor. The rotor may comprise a magnetic carrier or magnet holder. The rotor may also include one or more magnets held by or attached to the magnetic carrier. The rotor may also include a sleeve or housing which can receive or encase the magnet (s) therein. The rotor may also have at least one and preferably two circumferential or annular seals. The seals may be arranged to seal the magnet (s) within a space or opening provided between the magnet carrier and the sleeve. In this way, encapsulation of the magnet or magnets by use of the magnet carrier and the sleeve in conjunction with the gasket is used to fluidly isolate or protect the magnet (s) against chemicals in the environment in which he or she is working. This helps prevent damage to the magnet or magnets by harmful chemicals in the environment.

In a first embodiment, the first and second circumferential seals are disposed at axial ends of the magnet or magnets. Accordingly, the seals may be located or positioned at both ends of the magnet or magnets.

In one embodiment, the or each magnet extends axially between the first and second circumferential seals. Accordingly, the or each magnet may be disposed between the seals.

In one embodiment, the magnet carrier and the seal extend axially beyond the first and second annular seals. Accordingly, the magnet carrier and / or sleeve may pass the seals in the axial direction to retain the seals.

In one embodiment, the magnet carrier has an annular shoulder positioned to secure the or each magnet at an axial position on the magnet carrier. Accordingly, the magnetic carrier may have a shoulder or protrusion projecting radially from its outer surface and to which the or each magnet may abut to axially fix the or each magnet at the selected position on the magnetic carrier. This helps to align the magnet or magnets within the coils.

In one embodiment, the first circumferential seal is disposed near the annular shoulder. Accordingly, the annular shoulder may be positioned adjacent the first seal to aid in locating the first seal.

In one embodiment, the annular shoulder forms a first annular recess sized to receive the first circumferential seal. Accordingly, the annular shoulder may at least partially form or provide a portion of an annular groove on the outer surface of the magnetic carrier into which the annular seal may be inserted.

In one embodiment, the magnet carrier forms a second annular recess sized to receive the second circumferential seal. The provision of a further circumferential groove on the outer surface of the magnet carrier helps to hold the seal in place.

In one embodiment, the sleeve is held by the first and second circumferential seals. Accordingly, the sleeve can be positioned by the circumferential seals or held in place to the Sleeve, holding the magnet (s) and the seals in place.

In one embodiment, the sleeve and magnet carrier are sized to compress the first and second circumferential seals. Accordingly, the seals between the sleeve and the magnet carrier can be squeezed or squeezed to hold them in place and improve the sealing of the magnet or magnets.

In one embodiment, the first and second seals consist of a potting compound seal or an O-ring seal.

In one embodiment, the first and second circumferential seals are made of a synthetic rubber and fluoropolymer elastomeric compound.

In one embodiment, the magnet is a ring magnet.

In one embodiment, the ring magnet consists of a plurality of C-shaped magnet segments.

In one embodiment, the rotor on a holder which is operable to fix the magnet on the magnetic carrier.

In one embodiment, the magnet is a rare earth magnet.

In one embodiment, the magnet is made of iron-boron or samarium-cobalt.

In one embodiment, the first and second circumferential seals are arranged to hermetically seal the magnet within the space between the magnet carrier and the sleeve.

According to a second aspect, there is provided a vacuum pump having a motor rotor according to the first aspect.

Further particular and preferred aspects are set forth in the appended independent and dependent claims. Features of the dependent claims may be combined with features of the independent claims as necessary, even to combinations other than those expressly recited in the claims.

Where an apparatus feature is described in the context of effecting a function, it will be understood that this means any apparatus feature that perceives the function or that may be adapted or configured to perform that function.

• Die 1A bis 1D einen Motorläufer, allgemein mit 10 bezeichnet, gemäß einer Ausführungsform.

Embodiment examples of the present invention will now be described in more detail with reference to the accompanying drawings, in which:

• The 1A to 1D a motor rotor, generally designated 10, according to one embodiment.

Before discussing the embodiments in more detail, first an overview is given. An electric motor rotor assembly is provided which is less susceptible to chemical attack in harmful chemical environments. In particular, an arrangement is provided in which the magnet of the motor rotor and any adhesives used to attach the magnet to a magnet carrier are hermetically sealed against chemicals present in the environment in which the motor operates.

The magnet is typically an annular permanent magnet, which may be integrally formed or composed of C-shaped components, and which is received on a magnetic carrier. The magnet carrier forms part of a hermetically sealed shell to protect the magnet against chemical attack by chemicals present in the environment in which the motor rotor is used. In some embodiments, the magnet is attached to the magnet carrier using an adhesive. A cylindrical sleeve is coaxially disposed to enclose the magnet, the sleeve protecting the radially outer surface of the magnet against mechanical damage during assembly, assisting in holding the magnet in place under the action of strong centrifugal forces, and forming part of the hermetic seal Housing forms. At both ends of the magnet, a circumferential seal is provided which also forms part of the hermetically sealed shell, which seals the respective axial end of the magnet and completely encapsulates the magnet in an annular space formed by the motor support, sleeve and circumferential seals themselves. This hermetic encapsulation protects the annular permanent magnet against chemical attack during operation of the motor rotor and protects the adhesive, if any.

Rotor assembly:

1A shows a side view of a motor rotor, generally designated 10, according to an embodiment of the invention.

1B shows a longitudinal section through the motor rotor 10 ,

1C shows a perspective view of the motor rotor 10 ,

1D shows a further perspective view of the motor rotor 10 , The motor rotor 10 has a magnetic carrier 20 on. In this example, the magnet carrier 20 made of C45E carbon steel, which provides a good magnetic circuit for the magnet. The magnet carrier is an elongated cylinder with a profiled inner and outer surface, as will now be explained. The magnet carrier 20 defines a radially inner bore 25 , which is designed to receive a rotor shaft (not shown). The magnet carrier 20 has a radially outer surface 27 that is profiled. A first part 27A the outer surface 27 is cylindrical and extends from an axial end 30 to a first shoulder 27B that are radial from the first part 27A protrudes. A second shoulder 27d is radially in front of the first part 27A Off, is axially away from the first shoulder 27B arranged, and defined along with the first shoulder 27B an annular groove 27c , The second shoulder 27D protrudes radially by a height greater than that of the first shoulder 27B is.

The motor rotor 10 also has a surface ring permanent magnet 40 on, which has a cylindrical ring with a radially inner surface 43 , a radially outer surface 47 and annular ends 41 . 49 , having. In this embodiment, the surface ring permanent magnet 40 made of neodymium iron boron or samarium cobalt.

The motor rotor 10 also has O-ring seals 52, 50, each near the axial end 30 and inside the groove 27C are arranged. In this embodiment, the O-ring seals are made of Viton (Trade Mark). The first part 27A Can be optional with a slight groove near the axial end 30 be provided to assist the holding of the O-ring seal 52.

The motor rotor 10 also has a sleeve 60 which is arranged coaxially and the surface ring permanent magnet 40 and encloses the O-ring seals 50, 52 circumferentially. In this embodiment, the sleeve 30 made of stainless steel grade 303 in a cylinder with an inner surface 63 and an outer surface 65 shaped.

The assembly of the motor rotor 10 will now be described. The magnet carrier 20 is provided, and the surface ring permanent magnet 40 becomes from the axial end 30 along the axial length of the first part 27A pushed until it abuts the first shoulder 27B. One between the outer surface 27 and the inner surface 23 Incorporated adhesive bonds the surface ring permanent magnet 40 with the magnetic carrier 20 so that the magnet carrier 20 rotates when the surface ring permanent magnet 20 is driven by a surrounding coil (not shown) of the motor.

The O-ring 50 is in the groove 27C taken up, and the O-ring 50 is over the axial end 30 moves and abuts an axial end of the surface ring permanent magnet 40 and is through the slight groove near the axial end 30 (if provided) held.

The sleeve 60 is then from the axial end 30 via the O-ring 52 (of the surface ring permanent magnet 40 held in place) over the surface ring permanent magnet 40 (the first shoulder 27B held in place) and over the O-ring 50 (through the second shoulder 27D held in place).

Due to the relative dimensions of the magnet carrier 20 , the sleeve 60 and the O-rings 50, 52 compress the O-rings 50, 52 to form a hermetic circumferential seal at both ends of the surface-ring permanent magnet 40 manufacture.

Accordingly, it can be seen that the surface ring permanent magnet 40 hermetically sealed against the ingress of chemicals which the surface ring permanent magnet 40 itself or any for attaching the surface ring permanent magnet 40 to the magnet carrier 20 used adhesive could worsen.

Although the embodiment described above uses O-ring seals, it is clear that potting compounds can be used and that the profile of the outer surface 27 can be changed accordingly. It is also clear that the use of potting compounds typically occurs under vacuum conditions.

In the past, permanent magnet motor solutions have been used in light duty vacuum applications. Such permanent magnet motor solutions have been predominantly surface mount permanent magnet motor designs because of their cheaper and simpler design. However, as noted above, both the magnet and the adhesive are exposed to chemical attack in such constructions, particularly in medium or heavy duty vacuum applications.

The invention improves the robustness and reliability of surface mount permanent magnet motor designs with a hermetically sealed carrier designed to extend the utility of surface ring permanent magnet motors from light duty applications to medium and heavy duty vacuum applications.

Rare earth magnets and adhesives, especially neodymium-iron-boron, are used in certain vacuum applications, e.g. B. with high concentration levels of hydrogen and fluorine, endangered by long-term chemical attack. Over time, the adhesive and magnet assemblies may be weakened, resulting in poorer performance and ultimately engine failure. As a result of this failure, induction motors are typically used in medium and heavy duty vacuum applications, while surface ring permanent magnet motors are used only in light duty applications, particularly in semiconductor processing.

The invention provides a hermetically sealed magnet assembly which protects both the rare earth magnet and the adhesive against chemical attack. This results in a more reliable motor assembly for medium and heavy duty vacuum applications, thereby enabling the use of high efficiency synchronous motors in more semiconductor processing applications.

1. 1. Magnetträger aus C45E-Kohlenstoffstahl - dies ergibt einen guten magnetischen Kreis für den Magneten;
2. 2. zwei im Träger eingearbeitete O-Ringnuten - dies ergibt eine zuverlässige Positionierung für die beiden abdichtenden O-Ringe;
3. 3. zwei O-Ringe aus VITON - VITON (Handelsmarke) ist ein bewährtes Material für Vakuumanwendungen bei mittlerer und starker Beanspruchung;
4. 4. Magnetring aus Neodym-Eisen-Bor (NdFeB) - dies ergibt eine kosteneffektive Magnetlösung mit exzellenter Magnetstärke;
5. 5. Schutzhülse aus rostfreiem Stahl der Qualität 303.

Preferred embodiments have the following components:

1. 1. Magnetic carrier made of C45E carbon steel - this gives a good magnetic circuit for the magnet;
2. 2. two O-ring grooves machined in the carrier - this provides a reliable positioning for the two sealing O-rings;
3. 3. two VITON O-rings - VITON (trademark) is a proven material for medium and heavy duty vacuum applications;
4. 4. neodymium-iron-boron (NdFeB) magnetic ring - this results in a cost-effective magnetic solution with excellent magnetic strength;
5. 5. Quality stainless steel protective sleeve 303 ,

The use of O-rings made of VITON (trademark) produces a hermetic seal for the magnet and the adhesive. The compression of the O-rings keeps the stainless steel protective sleeve in place, eliminating the need for adhesive on the outer sealing surface.

The invention enables the use of surface ring permanent magnet motors in semiconductor vacuum applications. However, use in other industrial applications is also possible.

Although illustrative embodiments of the invention have been described in detail with reference to the accompanying drawings, it will be understood that the invention is not limited to this precise embodiment and that various modifications and changes may be made by those skilled in the art without departing from the concept of the invention. which is defined by the appended claims and their equivalents.

LIST OF REFERENCE NUMBERS

motor rotor 10 magnet carrier 20 inner bore 25 outer surface 27 first part 27A first shoulder 27B groove 27C second shoulder 27D axial end 30 permanent magnet 40 inner surface 43 outer surface 47 ring ends 41, 49 O-ring seals 52, 50 shell 60 inner surface 63 outer surface 65

Claims (18)

Motor rotor (10) with: a magnetic carrier (20); a magnet (40) carried by the magnet carrier (20); a sleeve (60) enclosing the magnet (40); and a first and a second circumferential seal (50, 52) arranged to seal the magnet (40) within a space between the magnet carrier (20) and the sleeve (60). Motor rotor (10) after Claim 1 wherein the first and second circumferential seals (52, 50) contact the axial ends (30) of the magnet (40) are arranged. Motor rotor (10) after Claim 1 or 2 wherein the magnet (40) extends axially between the first and second circumferential seals (50, 52). Motor rotor (10) according to one of Claims 1 to 3 wherein the magnet carrier (20) and the sleeve (60) extend axially beyond the first and second circumferential seals (50, 52). Motor rotor (10) according to one of Claims 1 to 4 wherein the magnetic carrier (20) has an annular shoulder (27D) which locates the magnet (40) at an axial position on the magnetic carrier (20). Motor rotor after Claim 5 wherein the first peripheral seal (50) is disposed near said annular shoulder (27D). Motor rotor (10) after Claim 5 or 6 wherein said annular shoulder (27D) defines a first circumferential groove dimensioned to receive the first circumferential seal (50). Motor rotor (10) according to one of Claims 1 to 7 wherein the magnet carrier (20) defines a second circumferential groove sized to receive the second circumferential seal (52). Motor rotor (10) according to one of Claims 1 to 8th wherein the sleeve (60) is held by the first and second circumferential seals (50, 52). Motor rotor (10) according to one of Claims 1 to 9 wherein the sleeve (60) and the magnet carrier (20) are sized to compress the first and second circumferential seals (50, 52). Motor rotor (10) according to one of Claims 1 to 10 wherein the first and the second circumferential seal (50, 52) are formed as Vergussmassendichtung or as an O-ring seal. Motor rotor (10) according to one of Claims 1 to 11 wherein the first and second circumferential seals (50, 52) are made of a synthetic rubber and fluoropolymer-elastomeric compound. Motor rotor (10) according to one of Claims 1 to 12 wherein the magnet (40) is a ring magnet. Motor rotor (10) after Claim 13 wherein the ring magnet (40) consists of a plurality of C-shaped magnet segments. Motor rotor (10) according to one of Claims 1 to 14 wherein the magnet (40) is a rare earth magnet. Motor rotor (10) according to one of Claims 1 to 15 wherein the magnet (40) consists of iron-boron or samarium-cobalt. Motor rotor (10) according to one of Claims 1 to 16 wherein the first and second circumferential seals (50, 52) are arranged to hermetically seal the magnet (40) within the space between the magnet carrier (20) and the sleeve (60). Vacuum pump with a motor rotor according to one of Claims 1 to 17 ,

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