KR200497518Y1 - Motor rotor - Google Patents

Abstract

A motor rotor and method are disclosed. The motor rotor includes a magnet carrier, a magnet supported by the magnet carrier, a sleeve surrounding the magnet, and first and second circumferential seals positioned to seal the magnet within a cavity between the magnet carrier and the sleeve. In this way, the magnet is encapsulated by reusing the magnet carrier and sleeve with a seal, thereby fluidically isolating or protecting the magnet from chemicals within the environment in which it operates. This helps prevent damage to the magnet caused by harmful chemicals in the environment.

Description

Motor rotor {MOTOR ROTOR}

The present invention relates to a motor rotor and method.

The motor is known. In an electric motor, a rotor assembly is provided that rotates relative to a non-rotating portion or stator. In one configuration of the motor, the stator includes one or more coils surrounding a rotor assembly having one or more magnets. Activation of the coil causes the rotor assembly to rotate within the stator.

US Patent Publication No. 2007/0140833

Motors are useful, but their operation can have unexpected results. Accordingly, it is desirable to provide an improved rotor.

According to a first aspect, there is provided a magnet carrier, a magnet supported by the magnet carrier, a sleeve surrounding the magnet, and positioned to seal the magnet within a void between the magnet carrier and the sleeve. A motor rotor is provided that includes first and second circumferential seals. A first aspect is that when operating a motor in a challenging environment, such as occurs when operating the motor in an aggressive chemical environment where chemicals in the environment can attack the rotor or degrade the performance of the rotor, It is recognized that it may be desirable to seal the magnet from such environments to maintain its performance.

Accordingly, a rotor is provided. The rotor may be for an electric motor. The rotor may include a magnetic carrier or holder. The rotor may also include one or more magnets supported by or secured to a magnet carrier. The rotor may also include a sleeve or housing that may surround or accommodate magnets therein. The rotor may also comprise at least one, preferably a pair of circumferential or annular seals. The seal may be positioned to seal the magnet within a cavity or opening created between the magnet carrier and the sleeve. In this way, the magnets are encapsulated by reusing the magnet carrier and sleeve with a seal, fluidically isolated or protected from chemicals in the operating environment. This helps prevent damage to the magnet caused by harmful chemicals in the environment.

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

In one embodiment, the magnet extends axially between the first and second circumferential seals. Accordingly, magnets can be provided between the seals.

In one embodiment, the magnet carrier and sleeve extend axially past the first and second circumferential seals. Accordingly, the magnetic carrier and/or sleeve may extend axially past the seal to maintain the seal.

In one embodiment, the magnet carrier has an annular shoulder positioned to position the magnet in an axial position on the magnet carrier. Accordingly, the magnet carrier may have a shoulder or protrusion extending radially from its outer surface, and the magnet abuts the shoulder or protrusion to position the magnet at an axially selected position on the magnet carrier. This helps align the magnet with the coil.

In one embodiment, the first circumferential seal is located proximate the annular shoulder. Accordingly, the annular shoulder may be disposed adjacent the first seal to assist in positioning the first seal.

In one embodiment, the annular shoulder defines a first circumferential recess dimensioned to receive a first circumferential seal. Accordingly, the annular shoulder can at least partially define or provide a portion of a circumferential groove on the outer surface of the magnetic carrier into which the circumferential seal can be seated.

In one embodiment, the magnet carrier defines a second circumferential recess dimensioned to receive a second circumferential seal. Providing additional circumferential grooves on the outer surface of the magnetic carrier helps keep the seal in place.

In one embodiment, the sleeve is retained by first and second circumferential seals. Accordingly, the sleeve can be placed on the circumferential seal or held in place by the circumferential seal to keep the sleeve, magnet, and seal in place.

In one embodiment, the sleeve and magnetic carrier are dimensioned to compress the first and second circumferential seals. Accordingly, a seal can be compressed or pressed between the sleeve and the magnet carrier to keep them in place and improve the sealing of the magnet.

In one embodiment, the first and second circumferential seals include at least one of a potting compound seal and an O-ring seal.

In one embodiment, the first and second circumferential seals include synthetic rubber and a fluoropolymer elastomer compound.

In one embodiment, the magnet includes a ring magnet.

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

In one embodiment, the rotor includes an operable fixing to secure the magnet to the magnet carrier.

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

In one embodiment, the magnet comprises one of the group comprising iron boron and samarium cobalt.

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

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

According to a third aspect, providing a magnet carrier, providing a magnet supported by the magnet carrier, and providing a sleeve surrounding the magnet, sealing the magnet within a cavity between the magnet carrier and the sleeve. A method is provided that includes positioning first and second circumferential seals.

In one embodiment, the method includes positioning first and second circumferential seals at axial ends of the magnet.

In one embodiment, the magnet extends axially between the first and second circumferential seals.

In one embodiment, the magnet carrier and sleeve extend axially past the first and second circumferential seals.

In one embodiment, the method includes positioning the magnet relative to an annular shoulder on the magnet carrier to position the magnet in an axial position on the magnet carrier.

In one embodiment, the method includes positioning the first circumferential seal proximate the annular shoulder.

In one embodiment, the method includes receiving a first circumferential seal within a first circumferential recess defined by an annular shoulder and dimensioned to receive the first circumferential seal.

In one embodiment, the method includes receiving a second circumferential seal within a second circumferential recess defined by a magnetic carrier.

In one embodiment, the method includes retaining the sleeve with first and second circumferential seals.

In one embodiment, the method includes dimensioning the sleeve and magnet carrier to compress the first and second circumferential seals.

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

In one embodiment, the first and second circumferential seals include synthetic rubber and fluoropolymer elastomeric compounds.

In one embodiment, the magnet includes a ring magnet.

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

In one embodiment, the method includes securing a magnet to a magnetic carrier.

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

In one embodiment, the magnet comprises one of the group comprising iron boron and samarium cobalt.

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

Additional specific and preferred aspects are set forth in the appended independent and dependent claims. Features of dependent claims may be combined with features of independent claims in combinations other than those explicitly set forth in the claims and as appropriate.

When a device feature is described as being operable to provide a functionality, this will be understood to include device features that provide such functionality or are adapted or configured to provide such functionality.

Now, embodiments of the present invention will be further described with reference to the accompanying drawings:
1A-1D illustrate motor rotors (collectively 10) according to one embodiment.

Before discussing the embodiments in more detail, an overview is first provided. Embodiments provide an electric motor rotor assembly that is less susceptible to chemical attack in harsh chemical environments. In particular, embodiments provide a construction in which the magnets of the motor rotor and any adhesive used to secure the magnets to the magnet carrier are hermetically sealed against chemicals present in the environment in which the motor operates. The magnets typically include surface ring permanent magnets that may be integral or formed as C-shaped components and are received on a magnet carrier. The magnet carrier forms part of a hermetically sealing enclosure to protect the magnets from chemical attack from chemicals present in the environment in which the motor rotor is placed. In some embodiments, the magnets are secured to the magnet carrier using adhesive. The cylindrical sleeve is positioned coaxially to surround the magnet, protecting the radial outer surface of the magnet from mechanical damage during assembly, helping to hold the magnet in place under strong centrifugal forces, and providing part of an airtight seal enclosure. . At both ends of the magnet, there is also a circumferential seal providing part of a hermetic seal enclosure, sealing each axial end of the magnet and completely enclosing the magnet within an annular cavity defined by the magnet carrier, sleeve and the circumferential seal itself. This is provided. Such an airtight seal protects the ring permanent magnets from chemical attack during operation of the motor rotor and protects any adhesive, if present.

rotor assembly

1A is a side view showing a motor rotor (collectively 10) according to one embodiment. 1B is a side cross-sectional view of the motor rotor 10. Figure 1c is a perspective view of the motor rotor 10. Figure 1D is another perspective view of the motor rotor 10. Motor rotor 10 includes a magnet carrier 20. In this example, the magnet carrier 20 is formed of C45E carbon steel to provide a good magnetic circuit for the magnets. The magnet carrier, as will now be explained, is an elongated cylindrical body with profiled inner and outer surfaces. The magnet carrier 20 defines a radially inner bore 25 configured to receive a rotor shaft (not shown). The magnet carrier 20 has a profiled radial outer surface 27 . The first portion 27A of the outer surface 27 is cylindrical and extends from the axial end 30 to a first shoulder 27B that stands radially upright from the first portion 27A. The second shoulder 27D is radially upright from the first portion 27A, is positioned axially away from the first shoulder 27B, and together with the first shoulder 27B defines a circumferential groove 27C. do. The second shoulder 27D stands erect in the radial direction to a height higher than that of the first shoulder 27B.

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

Motor rotor 10 also includes O-ring seals 52 and 50 respectively located proximate axial end 30 and within groove 27C. In this embodiment, the O-ring seal is made from Viton (trademark). The first portion 27A may optionally be provided with a shallow groove proximate the axial end 30 to assist in retaining the O-ring seal 52.

Motor rotor 10 also includes a sleeve 60 positioned coaxially with and circumferentially surrounding surface ring permanent magnets 40 and O-ring seals 50, 52. In this embodiment, sleeve 60 is grade 303 stainless steel formed into a cylindrical body having an inner surface 63 and an outer surface 65.

Now, the assembly of the motor rotor 10 will be described. A magnet carrier 20 is provided and the surface ring permanent magnet 40 is moved along the axial length of the first portion 27A from the axial end 30 until it abuts the first shoulder 27B. Any adhesive disposed between the outer surface 27 and the inner surface 43 adheres the surface ring permanent magnet 40 to the magnet carrier 20 so that the surface ring permanent magnet 40 is connected to the peripheral coil of the motor (as shown). causes the magnet carrier 20 to rotate when pressed by the magnet carrier (20).

O-ring 50 is received within groove 27C and O-ring 52 is moved over axial end 30 and abuts axial end of surface ring permanent magnet 40 (if provided) ) is maintained by a shallow groove proximal to the axial end (30).

Next, the sleeve 60 is pulled from the axial end 30, over the O-ring 52 (held in place by the surface ring permanent magnet 40), and over the surface ring permanent magnet 40 (the first shoulder). (held in place by 27B) upward, and above O-ring 50 (held in position by second shoulder 27D).

The relative dimensions of the magnet carrier 20, sleeve 60, and O-rings 50, 52 are such that the O-rings 50 form an airtight circumferential seal at both axial ends of the surface ring permanent magnet 40. , 52) is set to compress.

Accordingly, the surface ring permanent magnet 40 is susceptible to exposure to chemicals that may deteriorate the surface ring permanent magnet 40 itself or any adhesive used to secure the surface ring permanent magnet 40 on the magnet carrier 20. You can see that it is airtightly sealed against intrusion.

Although the above-described embodiment uses an O-ring seal, it will be appreciated that a potting compound could also be used, and the profile of the outer surface 27 could be altered accordingly. It will also be appreciated that application of such potting compounds typically occurs under vacuum conditions.

Previously, permanent magnet motor solutions tended to be for benign/light-duty vacuum applications. Surface ring permanent magnet motor designs have been the mainstream of such permanent magnet motor solutions due to their low cost and simple construction. However, as discussed above, both the magnet and adhesive in this design are susceptible to chemical attack, especially in medium harsh duty vacuum applications.

Embodiments demonstrate the robustness of surface ring permanent magnet motor designs by means of a hermetically sealed carrier designed to extend the application suitability of surface ring permanent magnet motors from light-duty load-lock applications to medium-severe vacuum applications. and improve reliability.

The use of rare earth magnets and adhesives, especially neodymium iron boron, is susceptible to long-term chemical attack, for example, high concentration levels of hydrogen and fluorine during certain vacuum applications. Over time, the adhesive and magnet assembly can weaken, leading to reduced performance and ultimately motor failure. As a result of these failure modes, induction motor technology is typically used for medium-severe vacuum applications, and surface ring permanent magnet motor technology has been used only for light-duty loadlock applications, particularly within semiconductor processing applications.

Embodiments provide a hermetically sealed magnetic construction that protects both the rare earth magnet and the adhesive from chemical attack. This provides a more reliable motor configuration for moderate to severe vacuum applications, thus enabling the use of high-efficiency synchronous motors in more semiconductor processing applications.

The example includes the following components:

1. C45E Carbon Steel Magnet Carrier – This provides a good magnetic circuit for the magnets;

2. Two O-ring grooves machined on the carrier - this provides reliable positioning of the two sealing O-rings;

3. Two Viton® O-Rings - Viton® is a proven material for medium to severe vacuum applications;

4. Neodymium Iron Boron (Nd Fe B) Magnet Ring - This provides a cost-effective magnet solution with excellent magnet strength;

5. Grade 303 stainless steel protective sleeve.

The use of Viton® O-rings provides an airtight seal for the magnet and adhesive. Additionally, the O-ring compression holds the protective stainless steel sleeve in place, thus eliminating the need for adhesion on the outer seal surface.

Embodiments enable the use of surface ring permanent magnet motors in semiconductor vacuum applications. However, this approach can be used in other industrial applications.

Although exemplary embodiments of the present invention have been disclosed in detail herein with reference to the accompanying drawings, it is understood that the present invention is not limited to the precise embodiments and that the scope of the present invention defined by the appended claims and equivalents thereof It will be understood that various changes and modifications may be made by those skilled in the art without deviation.

10: motor rotor 20: magnet carrier
25: inner bore 27: outer surface
27A: first part 27B: first shoulder
27C: Groove 27D: Second shoulder
30: axial end 40: permanent magnet
43: inner side 47: outer side
41, 49: annular end 52, 50: O-ring seal
60: sleeve 63: inner side
65: outer surface

Claims (18)

In the vacuum pump including a motor rotor,
The motor rotor is
A magnetic carrier,
A magnet supported by the magnet carrier,
a sleeve surrounding the magnet,
comprising first and second circumferential seals positioned to seal the magnet within a cavity between the magnet carrier and the sleeve;
The sleeve is a cylindrical body made of stainless steel,
The magnet carrier has a first annular shoulder arranged to position the magnet in an axial position on the magnet carrier, and a second annular shoulder positioned axially away from the first annular shoulder, the second annular shoulder stands radially upright from the outer surface of the magnet carrier to a height greater than the height of the first annular shoulder, and the first circumferential seal is located between the first annular shoulder and the second annular shoulder.
Vacuum pump. According to claim 1,
The first and second circumferential seals are located at axial ends of the magnet.
Vacuum pump. The method of claim 1 or 2,
The magnet extends axially between the first and second circumferential seals.
Vacuum pump. The method of claim 1 or 2,
wherein the magnetic carrier and the sleeve extend axially past the first and second circumferential seals.
Vacuum pump. delete delete According to claim 1,
The first and second annular shoulders define a first circumferential recess dimensioned to receive the first circumferential seal.
Vacuum pump. The method of claim 1 or 2,
The magnet carrier defines a second circumferential recess dimensioned to receive the second circumferential seal.
Vacuum pump. The method of claim 1 or 2,
The sleeve is retained by the first and second circumferential seals.
Vacuum pump. The method of claim 1 or 2,
the sleeve and the magnetic carrier are dimensioned to compress the first and second circumferential seals.
Vacuum pump. The method of claim 1 or 2,
wherein the first and second circumferential seals include one of a potting compound seal and an O-ring seal.
Vacuum pump. The method of claim 1 or 2,
The first and second circumferential seals include synthetic rubber and fluoropolymer elastomer compounds.
Vacuum pump. The method of claim 1 or 2,
The magnet includes a ring magnet
Vacuum pump. According to claim 13,
The ring magnet includes a plurality of C-shaped magnet segments.
Vacuum pump. The method of claim 1 or 2,
The magnet includes a rare earth magnet.
Vacuum pump. The method of claim 1 or 2,
The magnet comprises one of the group comprising iron boron and samarium cobalt
Vacuum pump. The method of claim 1 or 2,
the first and second circumferential seals are positioned to hermetically seal the magnet within the cavity between the magnet carrier and the sleeve.
Vacuum pump. delete