JP3217140U - Motor rotor - Google Patents

Abstract

An improved motor rotor is provided.
A motor rotor includes a magnet support 20, a magnet (permanent magnet 40) held by the magnet support, a sleeve 60 surrounding the magnet, and a gap between the magnet support and the sleeve. A first circumferential seal and a second circumferential seal (O-ring seals 52, 50) arranged to seal the magnet. Thus, in order to fluidly separate or protect the magnet from chemicals in the operating environment, the magnet is encapsulated by reusing the magnet support and sleeve in conjunction with the seal. This helps to prevent damage to the magnet caused by harmful chemicals in the environment.
[Selection] Figure 1B

Description

  The present invention relates to a motor rotor.

  Motors are known. In the electric motor, a non-rotating part, that is, a rotor assembly that rotates relative to the stator is provided. In one configuration of the motor, the stator has one or more coils surrounding a rotor assembly having one or more magnets. Energizing the coil causes the rotor assembly to rotate within the stator.

  While motors are useful, their operation can lead to unexpected results. Accordingly, it is desirable to provide an improved rotor.

  In a first aspect, a motor rotor is provided, the motor rotor including a magnet support, a magnet held by the magnet support, a sleeve surrounding the magnet, and a gap between the magnet support and the sleeve. A first circumferential seal and a second circumferential seal disposed to seal the magnet within the gap. The first aspect is to operate the motor in a harsh environment, for example found when driving the motor in a harsh chemical environment where chemicals in the environment can attack the rotor or degrade its performance. In some cases, it will be appreciated that it may be desirable to seal the magnet from its environment to maintain performance.

  Accordingly, a rotor is provided. The rotor can be for an electric motor. The rotor can comprise a magnet support or holder. The rotor can also comprise one or more magnets that are supported or fixed on a magnet support. The rotor can also include a sleeve or housing that surrounds or can be housed within the magnet. The rotor can also comprise at least one, preferably a pair of circumferential or annular seals. This seal can be arranged to seal the magnet in the gap or gap created between the magnet support and the sleeve. Thus, in order to fluidly separate or protect the magnet from chemicals in the operating environment, the magnet is encapsulated by reusing the magnet support and sleeve in conjunction with the seal. This helps to prevent damage to the magnet caused by harmful chemicals in the environment.

  In one embodiment, the first circumferential seal and the second circumferential seal are disposed at the axial end of the magnet. Thus, the seal can be placed or positioned at both ends of the magnet.

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

  In one embodiment, the magnet support and the sleeve extend axially beyond the first circumferential seal and the second circumferential seal. Thus, the magnet support and / or sleeve can extend axially beyond the seal to hold the seal.

  In one embodiment, the magnet support has an annular shoulder that is positioned to place the magnet in a predetermined axial position on the magnet support. Thus, the magnet support can have a shoulder or protrusion that rises radially from the outer surface against which the magnet abuts and places the magnet in a selected axial position on the magnet support. Can do. This helps align the magnet with the coil.

  In one embodiment, the first circumferential seal is disposed near the annular shoulder. Accordingly, the annular shoulder can be positioned near 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 the circumferential groove on the outer surface of the magnet support in which the circumferential seal can be seated.

  In one embodiment, the magnet support defines a second circumferential recess dimensioned to receive a second circumferential seal. Providing another circumferential groove on the outer surface of the magnet support helps to hold the seal in place.

  In one embodiment, the sleeve is held with a first circumferential seal and a second circumferential seal. Thus, to hold the sleeve, magnet, and seal in place, the sleeve can be placed on the circumferential seal or held in place.

  In one embodiment, the sleeve and magnet support are dimensioned to compress the first circumferential seal and the second circumferential seal. Thus, the seal can be compressed or compressed between the sleeve and the magnet support to hold it in place and improve magnet sealing.

  In one embodiment, the first circumferential seal and the second circumferential seal comprise one of an implantable resin seal and an O-ring seal.

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

In one embodiment, the magnet is comprised of a ring magnet.
In one embodiment, the ring magnet is composed of a plurality of C-shaped magnet segments.

In one embodiment, the rotor comprises anchoring means operable to secure the magnet to the magnet support.
In one embodiment, the magnet is comprised of a rare earth magnet.
In one embodiment, the magnet is composed of one of the group consisting of iron-boron and samarium cobalt.

  In one embodiment, the first circumferential seal and the second circumferential seal are arranged to hermetically seal the magnet within the gap between the magnet support and the sleeve.

  In a 2nd aspect, the vacuum pump provided with the motor rotor of the 1st aspect is provided.

  In a third aspect, a method is provided, the method comprising providing a magnet support, providing a magnet held on the magnet support, providing a sleeve surrounding the magnet, and a magnet support. Disposing a first circumferential seal and a second circumferential seal to seal the magnet within the gap between the sleeve and the sleeve.

  In one embodiment, the method includes disposing a first circumferential seal and a second circumferential seal at the axial end of the magnet.

In one embodiment, the magnet extends axially between the first circumferential seal and the second circumferential seal.
In one embodiment, the magnet support and the sleeve extend axially beyond the first circumferential seal and the second circumferential seal.

  In one embodiment, the method includes disposing the magnet against an annular shoulder on the magnet support and disposing the magnet at a predetermined axial position on the magnet support.

In one embodiment, the method includes placing a first circumferential seal near the annular shoulder.
In one embodiment, the method includes receiving a first circumferential seal in a first circumferential recess defined by an annular shoulder and sized to receive the first circumferential seal.
In one embodiment, the method includes receiving a second circumferential seal in a second circumferential recess defined by a magnet support.

In one embodiment, the method includes holding the sleeve with a first circumferential seal and a second circumferential seal.
In one embodiment, the method includes sizing the sleeve and magnet support to compress the first circumferential seal and the second circumferential seal.

In one embodiment, the first circumferential seal and the second circumferential seal comprise one of an implantable resin seal and an O-ring seal.
In one embodiment, the first circumferential seal and the second circumferential seal comprise a synthetic rubber and a fluoropolymer elastomer compound.

In one embodiment, the magnet is comprised of a ring magnet.
In one embodiment, the ring magnet is composed of a plurality of C-shaped magnet segments.

In one embodiment, the method includes securing the magnet to a magnet support.
In one embodiment, the magnet is comprised of a rare earth magnet.
In one embodiment, the magnet is composed of one of the group consisting of iron-boron and samarium cobalt.

  In one embodiment, the first circumferential seal and the second circumferential seal are arranged to hermetically seal the magnet within the gap between the magnet support and the sleeve.

  Further specific and preferred embodiments are listed in the attached independent and dependent claims. The features of the dependent claims can be combined with the features of the independent claims where appropriate and in combinations other than those explicitly listed in the claims.

Where a device feature is described as being operable to provide a function, it is understood that this includes a device feature that provides that function or is adapted or configured to provide that function. I want to be.
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

3 is a side view of the motor rotor 10. FIG. 2 is a side sectional view of the motor rotor 10. FIG. 1 is a perspective view of a motor rotor 10. FIG. 4 is another perspective view of the motor rotor 10. FIG.

  Before discussing the embodiments in detail, an outline will first be presented. Each embodiment provides an electric motor rotor assembly that is immune to chemical attack within a harsh chemical environment. Specifically, in each embodiment, the motor rotor magnet and any adhesive used to secure the magnet to the magnet support are hermetically sealed against chemicals present in the motor operating environment. Provide a configuration. In general, the magnet can be a unitary structure or can be formed of C-shaped components and comprises a surface annular permanent magnet housed on a magnet support. The magnet support forms part of a hermetically sealed housing for protecting the magnet from chemical attack from chemicals present in the environment in which the motor rotor is located. In some embodiments, the magnet is secured to the magnet support using an adhesive. The cylindrical sleeve is arranged coaxially to surround the magnet, protects the radially outward surface of the magnet from mechanical damage during assembly, helps hold the magnet in place under strong centrifugal force, Provides part of an airtight seal housing. Circumferential seals are provided on both sides of the magnet, which also provides part of the hermetic seal housing and seals each shaft end of the magnet, defined by the motor support, sleeve, and their circumferential seals Enclose the magnet completely in the annular gap. The hermetic seal protects the annular permanent magnet from chemical attack during operation of the rotor motor and, if present, any adhesive.

Rotor Assembly FIG. 1A is a side view illustrating a motor rotor, generally indicated at 10, according to one embodiment. FIG. 1B is a side sectional view of the motor rotor 10. FIG. 1C is a perspective view of the motor rotor 10. FIG. 1D is another perspective view of the motor rotor 10. The motor rotor 10 includes a magnet support 20. In this embodiment, the magnet support 20 is formed from C45E carbon steel that provides a good magnetic circuit for the magnet. The magnet support is an elongated cylinder with contoured inner and outer surfaces, as described below. The magnet support 20 defines a radially inner bore 25 that is shaped to receive a rotor shaft (not shown). The magnet support 20 has a contoured radially outer surface 27. The first portion 27A of the outer surface 27 is cylindrical and extends from the shaft end 30 to the first shoulder 27B, and the first shoulder rises in the radial direction from the first portion 27A. The second shoulder portion 27D rises in the radial direction from the first portion 27A, is disposed away from the first shoulder portion 27B in the axial direction, and together with the first shoulder portion 27B, the circumferential groove 27C is determined. The second shoulder portion 27D rises in the radial direction at a height greater than the height of the first shoulder portion 27B.

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

  Further, the motor rotor 10 includes O-ring seals 52 and 50, and is disposed close to the shaft end 30 and in the groove 27C. In this embodiment, the O-ring seal is made of Viton ™. The first portion 27 </ b> A can optionally be provided with a narrow groove near the shaft end 30 to assist in auxiliary retention of the O-ring seal 52.

  Further, the motor rotor 10 includes a sleeve 60, which is disposed coaxially with the surface annular permanent magnet 40 and the O-ring seals 50, 52 and surrounds them in the circumferential direction. In this embodiment, the sleeve 60 is grade 303 stainless steel formed into a cylinder having an inner surface 63 and an outer surface 65.

  The assembly of the rotor motor 10 will be described below. The magnet support 20 is prepared, and the surface annular permanent magnet 40 is moved from the shaft end 30 to the first portion 27A along the axial length until it comes into contact with the first shoulder 27B. Any adhesive located between the outer surface 27 and the inner surface 43 adheres the surface annular permanent magnet 40 to the magnet support 20, so that the surface annular permanent magnet 20 is energized by a peripheral coil (not shown) of the motor. Then, the magnet support 20 rotates.

  The O-ring 50 is accommodated in the groove 27 </ b> C, and the O-ring 52 moves on the shaft end 30 to contact the shaft end of the surface annular permanent magnet 40 (if provided) in a narrow groove near the shaft end 30. Retained.

  Next, the sleeve 60 is held on the O-ring 52 (held in place by the surface annular permanent magnet 40) from the shaft end 30 and on the surface annular permanent magnet 40 (held in place by the first shoulder 27B). Move up and on the O-ring 50 (held in place by the second shoulder 27D).

  The relative dimensions of the magnet support 20, the sleeve 60, and the O-rings 50, 52 are such that the O-rings 50, 52 are compressed to form an airtight circumferential seal at both axial ends of the surface annular permanent magnet 40. Yes.

  Thus, the surface annular permanent magnet 40 is free from chemical intrusions that may degrade the surface annular permanent magnet 40 itself or any adhesive used to secure the surface annular permanent magnet 40 on the magnet support 20. It can be understood that it is hermetically sealed.

  Although the foregoing embodiment uses an O-ring seal, it should also be understood that an embedding resin can be used and the contour of the outer surface 27 can change accordingly. It should also be understood that application of the embedding resin generally occurs under vacuum conditions.

  In the past, permanent magnet motor solutions have been rather for benign vacuum / low vacuum applications. Such permanent magnet motor solutions have mainly been concerned with the design of surface annular permanent magnet motors due to their inexpensive and simple structure. However, as mentioned above, both magnets and adhesives of these designs are susceptible to chemical attack, particularly in medium and high vacuum applications.

  Each embodiment uses a hermetically sealed support designed to extend the application suitability of a surface annular permanent magnet motor from low load lock applications to medium vacuum and high vacuum applications, and uses a surface annular permanent magnet motor. Improve design robustness and reliability.

  The use of rare earth magnets and adhesives, particularly neodymium-iron-boron, is subject to long-term chemical attack during certain vacuum applications, for example, high concentration levels of hydrogen and fluorine. Over time, the adhesive and magnet assembly can become brittle, leading to performance degradation and ultimately motor failure. As a result of this failure mode, induction motor technology has generally been used in medium and high vacuum applications, and surface annular permanent magnet motor technology is only used in light loadlock applications, especially semiconductor processing applications. .

  Each embodiment provides a hermetically sealed magnet configuration that protects both the rare earth magnet and the adhesive from chemical attack. This results in a more reliable motor configuration for medium vacuum and high vacuum applications, thus allowing high efficiency synchronous motors to be used in many semiconductor processing applications.

Each embodiment includes the following components.
1. C45E carbon steel magnet support—This provides a good magnetic circuit for the magnet.
2. Two O-ring grooves machined into the support-this allows reliable positioning for two O-ring seals.
3. Two VITON ™ O-rings-VITON ™ is a proven material for medium and high 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 a VITON ™ O-ring allows a hermetic seal for the magnet and adhesive. Also, O-ring compression holds the protective stainless steel sleeve in place, eliminating the need for adhesive on the outer seal surface.

  Each embodiment allows surface annular permanent magnet motors to be used for semiconductor vacuum applications. However, this approach can be used in other industrial applications.

  Exemplary embodiments of the present invention are disclosed in detail herein with reference to the accompanying drawings, but the present invention is not limited to the detailed embodiments, and those skilled in the art will be able to register a utility model. It should be understood that various changes and modifications can be made without departing from the scope of the invention as defined by the claims and their equivalents.

10 motor rotor 20 magnet support 25 inner bore 27 outer surface 27A first portion 27B first shoulder 27C groove 27D first shoulder 30 shaft end 40 permanent magnet 43 inner surface 47 outer surface 41, 49 annular end 52, 50 O-ring seal 60 Sleeve 63 Inner surface 65 Outer surface

Claims (18)

A magnet support;
A magnet held by the magnet support;
A sleeve surrounding the magnet;
A first circumferential seal and a second circumferential seal arranged to seal the magnet in a gap between the magnet support and the sleeve;
A motor rotor.   The motor rotor according to claim 1, wherein the first circumferential seal and the second circumferential seal are disposed at a shaft end of the magnet.   The motor rotor according to claim 1, wherein the magnet extends in an axial direction between the first circumferential seal and the second circumferential seal.   4. The motor rotor according to claim 1, wherein the magnet support and the sleeve extend in an axial direction beyond the first circumferential seal and the second circumferential seal. 5.   The motor rotor according to any one of claims 1 to 4, wherein the magnet support has an annular shoulder portion positioned so as to arrange the magnet at a predetermined axial position on the magnet support.   The motor rotor of claim 5, wherein the first circumferential seal is disposed near the annular shoulder.   7. A motor rotor as claimed in claim 5 or 6, wherein the annular shoulder defines a first circumferential recess dimensioned to accommodate the first circumferential seal.   The motor rotor according to any one of claims 1 to 7, wherein the magnet support defines a second circumferential recess dimensioned to accommodate the second circumferential seal.   The motor rotor according to claim 1, wherein the sleeve is held by the first circumferential seal and the second circumferential seal.   10. The motor rotor according to claim 1, wherein the sleeve and the magnet support have a size for compressing the first circumferential seal and the second circumferential seal. 11.   11. The motor rotor according to claim 1, wherein the first circumferential seal and the second circumferential seal comprise one of an implantable resin seal and an O-ring seal.   The motor rotor according to claim 1, wherein the first circumferential seal and the second circumferential seal are made of a synthetic rubber and a fluoropolymer elastomer compound.   The motor rotor according to claim 1, wherein the magnet is a ring magnet.   The motor rotor according to claim 13, wherein the ring magnet is composed of a plurality of C-shaped magnet segments.   The motor rotor according to claim 1, wherein the magnet is formed of a rare earth magnet.   The motor rotor according to any one of claims 1 to 15, wherein the magnet is composed of one of a group consisting of iron-boron and samarium cobalt.   17. The first circumferential seal and the second circumferential seal are arranged to hermetically seal the magnet in a gap between the magnet support and the sleeve. A motor rotor according to claim 1.   A vacuum pump comprising the motor rotor according to claim 1.

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