JP2020039212A - Rotor for outer rotor type motor, motor having the rotor, turbo molecular pump having the motor, and substrate rotation device having the motor - Google Patents

Abstract

To provide a rotor for suppressing concentration of stress inside a rotor core and/or an end ring.SOLUTION: A rotor for an outer rotor type motor includes: a rotor core 110 that is substantially cylindrical and divided into a plurality of independent arc sections; a plurality of metal bars 120 that are fixed to an inner peripheral section of the rotor core and extend in an axial direction of the rotor core; and end rings 130A and 130B for electrically connecting the plurality of metal bars with each other.SELECTED DRAWING: Figure 1C

Description

  The present invention relates to a rotor for an outer rotor type motor, a motor including the rotor, a turbo molecular pump including the motor, and a substrate rotating device including the motor.

  As a kind of vacuum pump for exhausting gas, there is a turbo molecular pump (TMP) that generates a vacuum by rotating a rotor blade at a high speed, and a screw groove type pump. Generally, the blade of a TMP is rotated by a motor. Patent Document 1 (Japanese Patent Application Laid-Open No. 2000-27789) discloses a TMP including an inner cylinder having a hollow portion and an outer rotor type motor provided on the outer periphery of the inner cylinder. A TMP as disclosed in Patent Document 1 is a rotatable moving blade, and includes a moving blade having a plurality of stages, a rotating portion supporting the moving blade, and a stationary blade provided alternately with respect to the moving blade. And a stationary blade having a plurality of stages.

JP-A-2000-27789

  In Patent Document 1, the structure of the rotor itself is not described in detail. Then, when the applicant examined the structure of the rotor, he found the following problem. The problem found by the applicant will be described with reference to FIGS. 1, 2, and 3. FIG.

  FIG. 1 is a schematic diagram showing a rotor 100 used in an outer rotor type induction motor. FIG. 1A is a top view of the rotor 100. FIG. 1B is a front exploded cross-sectional view of the rotor 100 taken along a cutting line indicated by “AA” in FIG. 1A. FIG. 1C is a front sectional view of the rotor 100 in an assembled state. The rotor 100 includes a rotor core 110, a metal bar 120 (in FIG. 1, only one metal bar is represented by a reference numeral), and an end ring 130. The rotor 100 forms at least a part of a motor 260 (see FIG. 2) in combination with a stator 250 (see FIG. 2) provided in a space in the inner circumferential direction of the rotor 100.

  FIG. 2 is a front sectional view of a TMP 200 using the rotor 100 of FIG. The TMP 200 includes a cylindrical inner cylinder 210, a motor 260 provided on an outer periphery of the inner cylinder 210, a moving blade 220 provided on an outer periphery of the motor 260, and an outer cylinder provided outside the moving blade 220, A stationary blade 230 provided inside the outer cylinder and outside the moving blade. More specifically, the rotor 100 is provided on the inner peripheral surface of the rotor blade 220. A stator 250 is provided on the outer peripheral surface of the inner cylinder 210 so as to face the rotor 100. At least a part of the motor 260 is constituted by the rotor 100 and the stator 250. Further, a seal member 270 is provided between the inner cylinder 210 and the bucket 220. Note that the seal member 270 may be in contact only with the inner cylinder 210, for example.

  FIG. 3 is a schematic diagram showing a rotor core 110 used in the rotor 100 of FIG. FIG. 3A is a top view of the rotor core 110. FIG. FIG. 3B is an enlarged view of a portion indicated by “B” in FIG. 3A.

  The rotor core 110 is a member for generating an induced current by interacting with a magnetic field generated by the stator 250. The rotor core 110 is substantially cylindrical (annular). The rotor core 110 may be formed, for example, from a steel plate. More specifically, rotor core 110 may be formed by stacking a plurality of (for example, 50) thin electromagnetic steel sheets (for example, 0.5 mm thick electromagnetic steel sheets) in the axial direction. The inner peripheral surface of the rotor core 110 is provided with a core groove 111 for inserting a metal bar 120 described later (in FIG. 1 and FIG. 3, only one core groove is denoted by a reference numeral). 1 and 3, the core groove 111 is a rectangular groove. 1 and 3, one core groove 111 is provided every 30 degrees, and the total number of core grooves 111 is twelve. However, it is also possible to adopt a core groove 111 different from the illustrated core groove 111. The core groove 111 may be a dovetail groove, for example. The number of the core grooves 111 (the pitch of the core grooves 111) is arbitrary.

  The metal bar 120 is inserted into the core groove 111. In other words, the metal bar 120 is fixed to the inner peripheral portion of the rotor core 110. Each of the metal bars 120 extends in the axial direction of the rotor core 110. FIG. 1 shows a rectangular parallelepiped metal bar 120 (in FIG. 1, only one metal bar is typically denoted by a reference numeral). In FIG. 1, the number of the metal bars 120 is twelve. The shape of the metal bar 120 is not limited to a rectangular parallelepiped as long as the shape corresponds to the core groove 111. In other words, as long as the shape corresponds to the shape of the metal bar 120, the shape of the core groove 111 is not limited. At least a part of the metal bar 120 is a conductor. Preferably, the metal bar 120 is formed from pure aluminum (“A1100” according to JIS standards) or an aluminum alloy, more specifically, an Al—Mg—Si-based alloy (“A6061” according to JIS standards). By forming the metal bar 120 from pure aluminum or an aluminum alloy, a lightweight metal bar 120 having rigidity and conductivity can be obtained.

  The rotor 100 includes an end ring 130. The end ring 130 is also called a “short-circuit ring” and is a member that electrically connects the metal bars 120 to each other. Specifically, an end ring 130A is provided on an upper end surface of the rotor core 110, and an end ring 130B is provided on a lower end surface of the rotor core 110. However, the "upper surface of the rotor core 110" is an upper surface located in FIGS. 1B, 1C, and 2. The “lower end face of the rotor core 110” is an end face located at a lower part in FIGS. 1B, 1C, and 2. End ring 130 is substantially cylindrical. Similar to the provision of the core groove 111 in the rotor core 110, the end ring 130 is provided with a ring groove 131 (in FIG. 1, only one ring groove is represented by a symbol). At least a part of the end ring 130 is a conductor. By forming the end ring 130 from an aluminum alloy, more specifically, an Al-Mg-Si-based alloy ("A6061" in the JIS standard), a lightweight end ring 130 having rigidity and conductivity can be obtained. .

  The metal bar 120 and the end ring 130 function as a current path for an induced current generated by the interaction between the rotor core 110 and the stator 250. The entire rotor 100 rotates due to Lorentz force between an induced current flowing through the metal bar 120 and the end ring 130 and a magnetic field generated by the stator 250. When the rotor 100 rotates, the moving blade 220 fixed to the outer periphery also rotates. The moving blade 220 is fixed to the rotor 100 by, for example, fitting the end ring 130 and the moving blade 220. More specifically, end ring 130 and rotor blade 220 are fixed by shrink fitting.

When the rotor 100 shown in FIG. 1 is rotated, each component of the rotor 100 receives a radial centrifugal force. Since the rotor core 110 and the end ring 130 have a substantially cylindrical shape, when the rotor core 110 and the end ring 130 receive centrifugal force, circumferential stress is generated inside the rotor core 110 and the end ring 130. . When the rotor core 110 receives a stress in the circumferential direction, the stress concentrates on the corners of the core groove 111 (portions surrounded by dotted lines in FIG. 3B). Similarly, stress concentrates on the corners of the ring groove 131. Since the rotation speed (rotation speed) of the rotor 100 can be tens of thousands of rpm or more, the stress applied to the corner of the core groove 111 and / or the corner of the ring groove 131 can be very strong. When the diameter of the rotor 100 increases as the size of the motor 260 increases, the generated centrifugal force may increase. Therefore, the stress applied to the corner of the core groove 111 and / or the corner of the ring groove 131 may further increase. The strong stress concentrated on the corners of the core groove 111 and / or the corners of the ring groove 131 may change the shape of the rotor core 110 and / or the end ring 130, and may eventually change the performance of the motor 260. In particular, when each component of the rotor 100 is thinned, the rigidity of each component can be reduced, so that the problem of stress concentration becomes significant.

  One object of the present application is to suppress the concentration of stress inside the rotor core 110 and / or the end ring 130.

  The present application provides, as an embodiment, a rotor for an outer rotor type motor, wherein the rotor is a substantially cylindrical rotor core, and the rotor core is divided into a plurality of independent arc portions. A rotor, comprising: a plurality of metal bars fixed to an inner peripheral portion, each metal bar extending in an axial direction of a rotor core, including a plurality of metal bars, and an end ring that electrically connects the plurality of metal bars. I do.

It is a top view of a rotor. FIG. 1B is an exploded front sectional view of the rotor taken along a cutting line indicated by “AA” in FIG. 1A. It is a front sectional view of a rotor in an assembled state. FIG. 2 is a front sectional view of a TMP using the rotor of FIG. 1. FIG. 2 is a top view of a rotor core used in the rotor of FIG. 1. FIG. 3B is an enlarged view of a portion indicated by “B” in FIG. 3A. It is a top view of the rotor core concerning one embodiment. FIG. 3 is a top view of an end ring and a metal bar welded to the end ring according to one embodiment. FIG. 5B is an enlarged view of a portion indicated by “C” in FIG. 5A. It is a front sectional view of the TMP provided with the motor provided with the spacer. FIG. 3 is a front sectional view of a substrate rotating device including a motor. It is a front sectional view of a substrate cleaning device provided with a substrate rotating device. It is a top view of a substrate processing device provided with a substrate cleaning device. It is the elements on larger scale of FIG. In FIG. 10, the vicinity of the motor is enlarged.

  Hereinafter, details of the embodiment of the invention according to the present application will be described with reference to FIGS. 4 to 7. Unless otherwise specified or unless contradiction arises, among the parts, parts, or elements shown in FIGS. 4 to 7, the parts already shown in FIGS. 3 may have the same or similar properties or characteristics as those of the parts shown in FIG.

<About split rotor core>
FIG. 4 is a top view showing the rotor core 110 according to one embodiment. Rotor core 110 may be formed of a metal (for example, aluminum) or may be formed of another material. “Other materials” may include, for example, FRP. The rotor core 110 of FIG. 4 includes a plurality of substantially arc-shaped parts. Hereinafter, the “substantially arc-shaped component” is referred to as “arc portion 400”. By combining the plurality of arc portions 400, the rotor core 110 has a substantially cylindrical shape as a whole. That is, the sum of the respective central angles of the arc portion 400 is approximately 360 °. 4 can be described as being divided into a plurality of arc portions 400. Here, "the rotor core 110 is divided into a plurality of arc portions 400" does not mean only "cutting one rotor core 110 into a plurality of arc portions 400". The plurality of arc portions 400 may be processed, formed, or manufactured from independent materials.

  In the example of FIG. 4, a substantially semicircular arc portion 400A and an arc portion 400B are shown. The arc portion 400A and the arc portion 400B are independent of each other. In other words, even when rotor 100 is assembled, arc portion 400A is not joined to arc portion 400B. Here, “coupling” and “contact” have different meanings. Therefore, it should be noted that a state may occur in which the arc portion 400A is in contact with the arc portion 400B, but the arc portion 400A is not connected to the arc portion 400B.

  In FIG. 4, the ends of the arc portions 400A and 400B are formed in a V-shape or an inverted V-shape. However, the shape of the ends of the arc portions 400A and 400B may be arbitrary. Also, although FIG. 4 has been described assuming that rotor core 110 is composed of two arc portions 400, rotor core 110 may be composed of three or more arc portions 400. In FIG. 4, for convenience of illustration, a gap having a size that can be seen is provided between the circular arc portion 400A and the circular arc portion 400B. However, if there is a large gap between the arc portions 400A and 400B, the performance of the motor 260 may not be the performance originally desired. Further, if there is a large gap between the arc portion 400A and the arc portion 400B, the rotation of the rotor 100 may be unbalanced. It is preferable that the specific shape and the like (including the size of the air gap) of the rotor core 110 be determined by the required output, rotation speed, stability, and the like of the motor 260.

  The rotor core 110 of FIG. 4 is divided into a plurality of independent arc portions 400. Therefore, even when the rotor core 110 receives centrifugal force, the circumferential stress generated inside the rotor core 110 of FIG. 4 is relatively weak. Therefore, the stress applied to the corner of the core groove 111 is also reduced. Providing the desired performance of the motor 260 and / or the TMP 200 or improving the performance of the motor 260 and / or the TMP 200 by employing the rotor 100 described herein that solves the stress problem. Can be.

  As described below, the thickness of the metal bar 120 in one embodiment may be smaller than the thickness of the metal bar 120 shown in FIG. Therefore, the depth of the core groove 111 in FIG. 4 may be smaller than the depth of the core groove 111 in FIG.

<About welding of end ring and metal bar>
As shown in FIG. 2, a rotor blade 220 is provided on the outer periphery of the rotor core 110. Therefore, when the rotor 100 shown in FIG. 4 is rotated, the arc portion 400A and the arc portion 400B push the bucket 220 radially outward.

When the moving blade 220 is pushed radially outward, the fitting pressure between the moving blade 220 and the end ring 130 is considered to decrease. In other words, when the rotor blade 220 is pushed radially outward, the force of pressing the end ring 130 from the outer periphery is considered to decrease. Therefore, the stress generated inside the end ring 130 when the rotor 100 is rotated may increase. At first glance, it seems that the problem of the stress generated inside the end ring 130 can be solved by configuring the end ring 130 from a plurality of independent parts similarly to the rotor core 110. However, since an induced current flows through the end rings 130, each of the end rings 130 is preferably formed integrally.

  In one embodiment, to solve the problem of stress concentration in the end ring 130, the metal bar 120 is joined to the end ring 130 by welding. Here, "welding" means welding in a broad sense. Specifically, “welding” includes “fusion welding”, “welding” and “brazing”. The welding between the end ring 130 and the metal bar 120 will be described with reference to FIG. FIG. 5A is a top view of the end ring 130 and the metal bar 120 welded to the end ring 130. FIG. 5B is an enlarged view of a portion indicated by “C” in FIG. 5A.

  In FIG. 5, the metal bar 120 is welded to the inner peripheral surface of the cylindrical end ring 130. Preferably, of the sides (edges) of the metal bar 120, the side that contacts the inner peripheral surface of the end ring 130 (portion surrounded by a dotted line in FIG. 5B) is joined by fusion welding. By fusion welding, the side of the metal bar 120 and the end ring 130 can be firmly joined. More preferably, of the surfaces of the metal bar 120, the surface facing the inner peripheral surface of the end ring 130 (the portion surrounded by the dashed line in FIG. 5B) is joined by brazing. When the metal bar 120 is formed in, for example, a quadrangular prism shape (in particular, a rectangular parallelepiped shape), a slight gap is generated between the metal bar 120 and the end ring 130. By using the brazing, the gap between the metal bar 120 and the end ring 130 can be filled. By filling the gap, the metal bar 120 and the end ring 130 can be firmly joined. In addition, by filling the gap, the metal bar 120 comes into surface contact with the end ring 130 (via the brazing material). Therefore, it is possible to ensure that a current flows between the metal bar 120 and the end ring 130. Expressed from a different perspective, the use of brazing eliminates the need for the contact surface of the metal bar 120 with the end ring 130 to have a shape along the inner circumference of the end ring 130. In other words, by using brazing, it becomes possible to use a square-bar-shaped, particularly rectangular parallelepiped metal bar 120. The quadrangular prismatic or rectangular parallelepiped metal bar 120 can be manufactured more easily than the partially curved metal bar 120.

  By joining the metal bar 120 to the end ring 130 by welding, the ring groove 131 becomes unnecessary. Therefore, it is possible to prevent stress from being concentrated on the corners of the ring groove 131. However, providing the end ring 130 with a groove structure such as the ring groove 131 after welding the metal bar 120 and the end ring 130 is not necessarily excluded. Further, the type of welding is not limited to the specified one. For example, the metal bar 120 and the end ring 130 may be joined by ultrasonic solder. The ultrasonic solder is a kind of welding, more specifically, a kind of brazing. Furthermore, only one of the side and the surface of the metal bar 120 may be joined by welding.

  As described above, in a preferred embodiment, both the metal bar 120 and the end ring 130 are formed of the same type of aluminum alloy, for example, an Al-Mg-Si-based alloy ("A6061" according to JIS standards). Therefore, the metal bar 120 can be easily welded to the end ring 130.

<About spacers>
When the rotor core 110 in FIG. 4 receives centrifugal force, the arc portion 400A itself and the arc portion 400B themselves receive a radial outward force. In other words, when the rotor core 110 rotates, the arc portion 400A and the arc portion 400B receive a force in a direction in which a gap between the arc portion 400A and the arc portion 400B expands. Therefore, when the rotor core 110 of FIG. 4 is rotated, the arc portions 400A and 400B push the rotor blades 220 radially outward. When the bucket 220 is pushed radially outward, the bucket 220 may be deformed. Deformation of the rotor blade 220 in the TMP may reduce the performance and life of the TMP. Even when the motor 260 is attached to a device other than the TMP, the rotor core 110 may deform a member installed on the outer periphery of the motor 260.

  In order to solve the problem of deformation of the members installed on the outer periphery of the moving blade 220 or the motor 260, the motor 260 according to an embodiment includes a spacer 600 (a spacer 600A and a spacer 600B). FIG. 6 is a front sectional view of the TMP 200 including the motor 260 including the spacer 600. As described later, since the spacer 600 is provided on the outer peripheral portion of the rotor 100, it can be said that the spacer 600 is a component located on the outermost peripheral portion of the motor 260. Therefore, in the configuration of FIG. 6, it can be expressed that “the moving blade 220 is provided on the outer peripheral portion of the motor 260”.

  The spacer 600 is a substantially cylindrical member. The spacer 600 is provided on the outer periphery of the rotor 100. Specifically, two spacers 600 (spacer 600A and spacer 600B) are arranged so as to sandwich rotor 100 from the axial direction of rotor 100. Each of the spacers 600 is fixed to each of the end rings 130 by fitting. More specifically, spacer 600A is fixed to end ring 130A by shrink fitting, and spacer 600B is fixed to end ring 130B by shrink fitting. When the spacer 600 pushes the end ring 130 from the outer periphery, the stress generated inside the end ring 130 can be reduced. The spacer 600 is preferably configured to be in contact with the rotor core 110 in order to prevent displacement and vibration. However, the spacer 600 may be configured so as not to contact the rotor core 110. The spacer 600 is used by being fitted into the bucket 220. More specifically, each of the spacers 600 and the rotor blade 220 are fixed by shrink fitting. It is preferable that the sum of the side areas of the two spacers 600 is larger than the side area of the rotor core 110 (the sum of the side areas of the arc portion 400A and the arc portion 400B).

  By interposing the spacer 600 between the rotor core 110 and the rotor blade 220, the rotor core 110 does not directly press the rotor blade 220. Even if the rotor core 110 pushes the spacer 600 radially outward, it is considered that the amount of deformation of the rotor blade 220 (or some component provided on the outer peripheral portion of the motor 260) is reduced because the spacer 600 has a large side area.

  Preferably, spacer 600 is formed from a lightweight and rigid aluminum alloy. The spacer 600 is not a member intended to be a current path for an induced current. Therefore, unlike the end ring 130 and the metal bar 120, it is not necessary to increase the conductivity of the spacer 600. Therefore, the spacer 600 may be formed from duralumin, super duralumin, or ultra super duralumin (each of which is “A2017”, “A2020”, and “A7075” in the JIS standard). Further, the material of the spacer 600 is not limited to an aluminum alloy. For example, the spacer 600 may be formed from a non-magnetic stainless material (for example, SUS630 or the like). Such a stainless material may have, for example, a resistivity about 20 times higher than pure aluminum. Further, the spacer 600 may be formed from a high-strength resin material FRP or carbon fiber.

Further, it is preferable that the spacer 600A and the spacer 600B are not electrically in contact with each other. More specifically, a gap is provided between spacer 600A and spacer 600B. By electrically non-contacting each of the two spacers 600, it is possible to ensure that the induced current flows through the current path (end ring 130 and metal bar 120) where the induced current should flow. When the rotor core 110 is a laminated body, it is preferable that the length of the gap between the two spacers 600 in the axial direction is smaller than the thickness of one layer of the rotor core 110. For example, when rotor core 110 is a laminate of 0.5 mm thick electromagnetic steel sheets, the gap between two spacers 600 may be 0.2 mm. Reducing the gap allows the spacer 600 to support all layers of the rotor core 110.

  The spacer 600 may be formed of a conductor such as an aluminum alloy. When the spacer 600 has conductivity, a current (induction current) generated inside the motor 260 may flow through a current path other than a desired current path. To further ensure that the induced current flows in the desired current path, at least one, and preferably both, of spacer 600A and spacer 600B may have an insulating layer. FIG. 10 is a partially enlarged view of FIG. In FIG. 10, the vicinity of the motor 260 is enlarged. However, each of the spacers 600A and 600B in FIG. 10 is different from that in FIG. The insulating layer 1000 may be formed by resin coating. However, the insulating layer 1000 may be formed by another method. . The insulating layer 1000 is provided at least between the spacer 600 and the end ring 130 and between the spacer 600 and the rotor core 110. The insulating layer 1000 insulates the spacer 600 from the end ring 130 and insulates the spacer 600 from the rotor core 110.

<About the thickness of the metal bar>
When the thickness of the metal bar 120 is large, the stress inside the metal bar 120 when the rotor 100 is rotated increases. By using the thin metal bar 120, the stress generated inside the metal bar 120 can be reduced. On the other hand, as described later, the value of the copper loss changes depending on the thickness of the metal bar 120.
The applicant has found that there is an optimum solution (a local solution if not the optimum solution) for the thickness of the metal bar 120. It is considered that by optimizing the thickness of the metal bar 120 and minimizing the copper loss, the performance of the motor 260 and thus the performance of the TMP 200 can be improved.

The thickness of the metal bar 120 will be described in detail below. In the following, the dimensions and characteristics of each component are represented by the following symbols (for symbols, see also FIGS. 5 and 6). However, it is assumed that the end rings 130A and 120B have the same shape with the upside down.
x: Thickness of metal bar 120 (unit is meter)
w: width of metal bar 120 (unit is meter)
l _bar : length of metal _bar 120 in the axial direction (can also be expressed as height of metal bar 120, unit is meter)
l _ring : length in the axial direction of end ring 130 (can also be expressed as height of end ring 130, unit is meter)
r _inner : the inner radius of the rotor 100 (can also be expressed as half the distance between one metal bar 120 and the metal bar 120 facing the metal bar 120, the unit is meter)
r _outer : outer radius of end ring 130 (unit is meter)
ρ _bar : resistivity of metal _bar 120 (unit is ohm meter)
R _bar : Sum of resistance values of all metal bars 120 (unit is ohm)
ρ _ring : resistivity of end ring 130 (unit is ohm meter)
R _ring : Sum of resistance values of all end rings 130 (unit is ohm)
R _total : sum of resistance values of all metal bars 120 and all end rings 130, that is, the sum of R _bar and R _ring (unit: ohm)
n _bar : number of metal bars 120 (dimensionless number)
n _ring : number of end rings 130 (dimensionless number)
When the actual dimensions of the metal bar 120 and the end ring 130 differ depending on the location, the average value of the actual dimensions may be used for the calculation. For example, when the metal bar 120 has a dovetail shape, the “average value of the lengths of the two bottom sides (upper and lower bases) of the metal bar 120” may be set as the width w of the metal bar 120.

It is assumed that r _inner is a constant. This means that if the shape of the stator 250 is constant, the gap length between the rotor 100 and the stator 250 is constant. Further, let r _{outer be} a constant. This is a numerical value determined by the size of a member (for example, the moving blade 220) attached to the outside of the stator 250, particularly the inner diameter of the member.

First, from the definition of resistivity, the relationship between x and R _ring , R _bar, and R _total can be described by the following function.

Copper loss is determined by “resistance × (square of current value)”. Therefore, when the current value is constant, the copper loss is also minimized when the resistance value is minimized. That is, by determining the value of x so that R _total is minimized, it is possible to obtain the motor 260 with the least copper loss.

As an example, the desired value of x is calculated for a rotor 100 having the following dimensions and characteristics. Note that x is a value larger than 0, although it is obvious.
w = 0.012 (m)
l _bar = 0.053 (m)
l _ring = 0.014 (m)
r _inner = 0.2085 (m)
r _outer = 0.214 (m)
ρ _bar = 2.8 × 10 ⁻⁸ (Ωm)
ρ _ring = 5.6 × 10 ⁻⁸ (Ωm)
n _bar = 36 (books)
n _ring = 2 (pieces)
In this case, x is a value smaller than 0.0055 (m) (0.214 (m) -0.2085 (m) = 0.0055 (m)). This is because if x takes a value of 0.055 m or more, the thickness of the end ring becomes a negative value.

When each of the above values is used, A = 2.51 × 10 ⁻⁵ (Ω) and B = 4.45 × 10 ⁻⁶ (Ωm). _Therefore, by determining the value of x such that _{R total} is the first derivative of _{(x) R 'total (x} ) = 0, R total (x) becomes a minimum, to minimize the copper loss be able to. The method of deriving x based on the first derivative is shown by the following equation.

When the above values are substituted into the constants A, B, r _inner and r _outer , R ′ _total (x) = 0 when x = 2.15 × 10 ⁻³ in calculation. Therefore, in this example, by setting the thickness of the metal bar 120 to about 2.2 mm, it is possible to obtain the motor 260 with small copper loss.

<Motor application examples>
In the description so far, the motor 260 is a TMP motor. However, the applicable range of the motor 260 is not limited to TMP. An application example of the motor 260 will be described with reference to FIG. FIG. 7 is a front sectional view of a substrate rotating device 700 for rotating a substrate 730 such as a semiconductor. The substrate rotating device 700 includes an inner cylinder 710, a motor 260 attached to an outer peripheral portion of the inner cylinder 710, and a substrate supporter 720 provided on the outer periphery of the motor 260, and a substrate for supporting the substrate 730. And a support portion 720. Instead of the inner cylinder 710, a solid cylindrical member can be used. The motor 260 in FIG. 7 has, for example, a configuration equivalent to the motor 260 illustrated in FIG. By combining the substrate rotation device 700 with another device, for example, a substrate polishing device, a substrate cleaning device, a substrate processing device, or the like, it becomes possible to process the substrate while rotating the substrate 730. The device to which the motor 260 can be applied is not limited to the TMP 200 and the substrate rotating device 700.

  An example of an apparatus for processing a substrate while rotating the substrate by the substrate rotating apparatus will be described with reference to FIG. FIG. 8 is a front sectional view of a substrate cleaning apparatus 800 including a substrate rotating apparatus 700 '. The substrate rotating device 700 'of FIG. 8 has substantially the same structure as the substrate rotating device 700 of FIG. 7, except for the substrate support 720'. 8 is configured to support the edge of the substrate 730, unlike the substrate support 720 of FIG. Therefore, in the configuration of FIG. 7, both sides of the substrate 730 can be accessed. For convenience of illustration, some of the components of the substrate rotation device 700 'are not numbered (see FIG. 7).

  The substrate cleaning apparatus 800 includes a substrate rotating device 700 ', a housing 810, a cleaning arm (820U and 820L), a cup 830, and a downflow generator 840. The housing 810 contains other components of the substrate cleaning apparatus 800. The substrate support portion 720 is rotatably attached to the housing 810 via a bearing (not shown) such as a ball bearing. The inner cylinder 710 may be a part of the housing 810. The substrate 730 is transported from a load port (not shown) of the housing 810 toward the substrate support 720 '.

  The substrate cleaning apparatus 800 includes a cleaning arm for cleaning the substrate 730 supported by the substrate support 720 '. The substrate cleaning apparatus 800 according to an embodiment includes an upper arm 820U (“U” upper) for cleaning the substrate 730 from above the substrate 730, and a lower arm 820L (“L”) for cleaning the substrate 730 from below the substrate 730 ( “L” ower). Each arm allows both sides of the substrate 730 to be cleaned. Upper arm 820U and lower arm 820L are configured to be vertically movable. As each arm moves up and down, the cleaning of the substrate 730 is started or stopped. Upper arm 820U and lower arm 820L are further configured to be horizontally movable. The area of the substrate 730 to be cleaned is determined by the horizontal movement of each arm. The lower arm 820L can come into contact with the substrate 730 via the hollow portion of the inner cylinder 710.

  Specifically, a cleaning member 821 and a liquid supply nozzle 822 are provided at the respective distal ends of the upper arm 820U and the lower arm 820L. In this technical field, the cleaning member 821 is also referred to as a “pencil-shaped cleaning member”. With the cleaning member 821 in contact with the substrate 730, the substrate 730 is cleaned by the substrate rotating device 700 'rotating the substrate 730. The liquid supply nozzle 822 supplies a liquid for cleaning the substrate 730, for example, a cleaning liquid or pure water, to the substrate 730.

  In the configuration of FIG. 8, the liquid may adhere to the substrate support 720 'and the substrate 730. When these members are rotated, liquid can be scattered from these members by centrifugal force. The substrate cleaning apparatus 800 includes a cup 830 for receiving the scattered liquid. The upper end of the cup 830 is positioned higher than the upper ends of at least one, preferably both, of the substrate support 720 'and the substrate 730. Further, the cup 830 has a ring shape whose upper part is inclined toward the rotation axis of the substrate rotation device 700 '. By configuring the cup 830 in this manner, the cup 830 can receive the liquid scattered from the substrate support portion 720 'or the like. The received liquid may be discharged from a drain port (not shown) to the outside of the substrate cleaning apparatus 800. Cup 830 may be rotatable or non-rotatable. When the cup 830 is rotated together with the substrate support 720 ', further scattering of the liquid when the liquid collides with the cup 830 can be suppressed. On the other hand, the non-rotatable cup 830 has the advantages of a simple configuration and low cost.

  A downflow generator 840 is provided above the substrate cleaning apparatus 800. Downflow generator 840 generates a downflow in housing 810. By controlling the airflow in the housing 810, the behavior of the fine particles (foreign matter) in the housing 810 can be controlled.

8 and the description related to FIG. 8 clarify details of the substrate cleaning apparatus including the substrate rotating apparatus including the motor according to the embodiment. Note, however, that FIGS. 7 and 8 are merely exemplary. For example, substrate cleaning apparatus 800 may have only one of upper arm 820U and lower arm 820L. For example, instead of the cleaning member 821, a mechanism for cleaning the substrate by ejecting a liquid at a high pressure may be used. In addition, specific configurations of the substrate rotating device (700, 700 ') and the substrate cleaning device 800 may be appropriately determined by those skilled in the art. According to the substrate cleaning apparatus of one embodiment, the substrate can be more appropriately cleaned while rotating the substrate at high speed and surely.

  An example of an apparatus including the substrate cleaning apparatus 800 of FIG. 8 will be described with reference to FIG. FIG. 9 is a top view schematically showing a substrate processing apparatus 900 including a substrate cleaning apparatus 800. The substrate processing apparatus 900 shown in FIG. 9 includes a load / unload unit 910, a polishing unit 920, and a wafer station 930. The substrate processing apparatus 900 further includes a substrate transport unit 940, a substrate cleaning unit 950, and a control unit 960.

  The load / unload unit 910 may include a FOUP 911 and a transfer robot 912 of the load / unload unit. The polishing unit 920 may include a first polishing device 921, a second polishing device 922, a third polishing device 923, and a fourth polishing device 924. Each polishing device may be, for example, a CMP device. The substrate cleaning unit 950 may include one or more (three in FIG. 9) substrate cleaning apparatuses 800. The substrate cleaning unit 950 may further include a first cleaning unit transfer robot 954 and a second cleaning unit transfer robot 955.

  The substrate is loaded by the loading / unloading unit 910. The loaded substrate is transferred to the polishing unit 920 by the transfer robot 912, for example. In addition to or instead of the transfer robot 912, the substrate transfer unit 940 may transfer the loaded substrate. The substrate polished by the polishing unit 920 is stored in the wafer station 930 by the substrate transfer unit 940. The substrate housed in the wafer station 930 is taken out by the first cleaning unit transfer robot 954. The first cleaning unit transfer robot 954 transfers the substrate to one substrate cleaning apparatus 800. The substrate is cleaned by the substrate cleaning device 800. The cleaned substrate is transferred by the first cleaning unit transfer robot 954 and / or the second cleaning unit transfer robot 955. The cleaned substrate may be further cleaned by another substrate cleaning apparatus 800. The cleaned substrate can be removed from the substrate processing apparatus 900 by, for example, the second cleaning unit transfer robot 955, the substrate transfer unit 940, and / or the transfer robot 912.

  The substrate processing apparatus 900 according to one embodiment can appropriately clean the substrate polished by the polishing unit 920 by the substrate cleaning apparatus 800. Note that FIG. 9 is for illustration only. The specific configuration of the substrate processing apparatus 900 may be appropriately determined by those skilled in the art.

  The embodiments of the present invention have been described above. The embodiments of the present invention described above are intended to facilitate understanding of the present invention, and do not limit the present invention. The present invention can be modified and improved without departing from the gist thereof, and the present invention naturally includes equivalents thereof. In addition, in a range in which at least a part of the above-described problem can be solved, or in a range in which at least a part of the effect is achieved, any combination of the components described in the claims and the specification, or omission is possible. It is. Motor 260 may not include all of the elements or features disclosed herein. As an example, it is possible to use a motor 260 including the rotor core 110 at least partially constituted by the plurality of arc portions 400, in which the end ring 130 and the metal bar 120 are not welded. As a further example, it is also possible to use a motor 260 including the rotor core 110 at least partially constituted by the plurality of arc portions 400 and not including the spacer 600.

The present application provides, as an embodiment, a rotor for an outer rotor type motor, wherein the rotor is a substantially cylindrical rotor core, and the rotor core is divided into a plurality of independent arc portions. A rotor, comprising: a plurality of metal bars fixed to an inner peripheral portion, each metal bar extending in an axial direction of a rotor core, including a plurality of metal bars and an end ring that electrically connects the plurality of metal bars. I do.

  This rotor has an effect of reducing the stress generated inside the rotor core as an example.

  Further, the present application discloses, as one embodiment, a rotor in which the metal bar is welded to the inner peripheral surface of the end ring.

  This rotor has an effect of reducing the stress generated inside the end ring as an example.

  Further, the present application discloses, as an embodiment, a rotor in which the metal bar has a rectangular parallelepiped shape or a dovetail shape, and the thickness of the metal bar is equal to or less than half the width of the metal bar.

  This rotor has an effect of reducing the stress generated inside the metal bar as an example.

  Further, in the present application, as one embodiment, of the sides of the metal bar, the side that contacts the inner peripheral surface of the end ring is fusion-welded, and the surface of the metal bar that faces the inner peripheral surface of the end ring is brazed. A rotor is disclosed.

  This rotor has an effect of securing the metal bar and the end ring and ensuring conduction between the metal bar and the end ring as an example.

  Further, the present application discloses, as one embodiment, a motor including the rotor described in this specification and a stator provided in a space in the inner circumferential direction of the rotor so as to face the rotor.

  This disclosure makes it clear that the rotor described herein is applicable to motors.

  Further, the present application discloses, as one embodiment, a motor including a substantially cylindrical spacer provided on the outer periphery of the rotor. Further, the present application discloses, as one embodiment, a motor in which a side area of the spacer is larger than a side area of the rotor core.

  These motors have an effect that deformation of a member (for example, a moving blade of a TMP) installed on the outer periphery of the motor can be suppressed as an example.

  Further, according to the present application, as an embodiment, the rotor includes two end rings, each of the end rings is provided on each of the end faces of the rotor core, the motor includes two spacers, and each of the spacers includes: It is fixed to each of the end rings, each of the spacers is electrically non-contact, and the surface of the spacer has a surface for insulating the end ring and the spacer and for insulating the rotor core and the spacer. A motor provided with an insulating layer is disclosed.

  This motor has an effect that the induced current can be ensured to flow through a current path that should flow as an example.

Further, in the present application, the rotor core is a laminate of a plurality of plates, and the spacer is configured so that a gap is provided between each of the spacers.
A motor is disclosed that is smaller than the thickness of the layers.

  This motor has as an example the effect that the spacer can support all layers of the rotor core.

  Further, the present application provides, as an embodiment, an inner cylinder, a motor provided in the inner cylinder, a motor described in this specification, a moving blade provided on the outer periphery of the motor, and an outer cylinder provided outside the moving blade. And a stationary blade provided inside the outer cylinder and outside the moving blade. Further, the present application includes, as an embodiment, an inner cylinder, a motor according to any one of claims 5 to 9 provided in the inner cylinder, and a substrate supporter provided on an outer periphery of the motor. A substrate rotating device is disclosed.

  With these disclosures, a specific device to which the motor described in this specification is applied is described.

DESCRIPTION OF SYMBOLS 100 ... Rotor 110 ... Rotor core 111 ... Core groove 120 ... Metal bar 130 ... End ring 131 ... Ring groove 210 ... Inner cylinder 220 ... Moving blade 230 ... Stationary wing 240 ... Outer cylinder 250 ... Stator 260 ... Motor 270 ... Seal member 400 ... Arc Unit 600: Spacers 700, 700 ': Substrate rotating device 710: Inner cylinder 720, 720': Substrate support unit 730: Substrate 800: Substrate cleaning device 810: Housing 820U, 820L: Cleaning arm (upper arm, lower arm)
821 Cleaning member 822 Liquid supply nozzle 830 Cup 840 Downflow generator 900 Substrate processing device 910 Load / unload unit 912 Transport robot 920 Polishing unit 921 First polishing device 922 Second polishing Apparatus 923 Third polishing apparatus 924 Fourth polishing apparatus 930 Wafer station 940 Substrate transport unit 950 Substrate cleaning unit 954 First cleaning section transport robot 955 Second cleaning section transport robot 960 Control Part 1000: insulating layer

Claims (11)

A rotor for an outer rotor type motor, wherein the rotor is:
A substantially cylindrical rotor core, the rotor core being divided into a plurality of independent arcs;
A plurality of metal bars fixed to the inner peripheral portion of the rotor core, each metal bar extending in the axial direction of the rotor core, a plurality of metal bars,
An end ring for electrically connecting the plurality of metal bars to each other;
A rotor comprising:   The rotor according to claim 1, wherein the metal bar is welded to an inner peripheral surface of the end ring. The rotor according to claim 2, wherein
The metal bar has a rectangular parallelepiped shape or a dovetail shape,
The rotor, wherein a thickness of the metal bar is equal to or less than half a width of the metal bar. The rotor according to claim 3, wherein
The side of the side of the metal bar that contacts the inner peripheral surface of the end ring is fusion-welded,
The rotor, wherein a surface of the metal bar facing the inner peripheral surface of the end ring is brazed. A rotor according to any one of claims 1 to 4,
A stator provided in a space in an inner circumferential direction of the rotor, the stator facing the rotor,
A motor.   The motor according to claim 5, further comprising a substantially cylindrical spacer provided on an outer periphery of the rotor.   7. The motor according to claim 6, wherein a side area of the spacer is larger than a side area of the rotor core. The motor according to claim 6 or 7,
The rotor includes two end rings,
Each of the end rings is provided on each of the end faces of the rotor core,
The motor includes the two spacers,
Each of the spacers is fixed to each of the end rings,
Each of the spacers is electrically non-contact;
On the surface of the spacer, an insulating layer for insulating the end ring and the spacer and for insulating the rotor core and the spacer is provided.
motor. The motor according to claim 8, wherein
The rotor core is a laminate of a plurality of plates,
The spacer is configured such that a gap is provided between each of the spacers,
The motor, wherein an axial length of the gap is smaller than a thickness of one layer of the rotor core. An inner cylinder,
The motor according to any one of claims 5 to 9, which is provided on an outer periphery of the inner cylinder,
Rotor blades provided on the outer periphery of the motor;
An outer cylinder provided outside the rotor blade,
Stationary vanes provided inside the outer cylinder and outside the moving blades,
A vacuum pump. An inner cylinder,
The motor according to any one of claims 5 to 9, wherein the motor is provided in the inner cylinder.
A substrate supporting portion provided on the outer periphery of the motor,
A substrate rotating device comprising:

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