JPH0730395U - Turbo molecular pump - Google Patents

Abstract

(57) [Summary] [Object] To provide a turbo molecular pump capable of effectively performing heat removal (cooling) and baking of a rotor and improving response speed and accuracy in rotor temperature control. A heat insulating portion 12 is provided on an inner peripheral surface of the rotor 2 and a surface of a stator column 7 facing the inner peripheral surface of the rotor 2, and a heat transfer portion 13 is provided on an outer peripheral surface of the rotor 2 and an inner wall surface of the casing 1 facing the outer peripheral surface.
To provide. The heat insulating part 12 is formed of a mirror-finished layer of silver or the like to set the thermal emissivity low, while the heat transfer part 13 is formed of a ceramic layer to set the thermal emissivity high. The heat transfer between the stator column 7 and the rotor 2 by radiation is blocked by the heat insulating section 12, and the heat transfer by radiation between the casing 1 and the rotor 2 is accelerated by the heat transfer section 13.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a turbo molecular pump that rotatively rotates a rotor to give kinetic energy to molecules by the stator blades and rotor blades to exhaust the molecules, and in particular, heat removal (cooling) of the rotor for the purpose of reducing gas emission during pump operation. In addition, the response speed and accuracy in the temperature control of the rotor for the purpose of effectively performing the baking work for the purpose of removing adsorbed molecules that cause gas release and for preventing the deposition of reactive products It is possible to improve.

[0002]

[Prior art]

 Conventionally, this type of turbo-molecular pump has a cylindrical rotor 2 rotatably arranged inside a casing 1 as shown in FIG. 2, and between a peripheral surface of the rotor 2 and an inner wall surface of the casing 1. Has stator blades 3 and rotor blades 4 arranged alternately along the axis of the rotor 2. The stator blades 3 are fixed to the inner wall surface of the casing 1 via spacer rings 5, and the rotor blades 4 are fixed to the rotor 2 Is disposed on the outer peripheral surface of the.

A rotor shaft 6 and a stator column 7 are provided on the inner peripheral surface side of the rotor 2, and the tip end of the rotor shaft 6 is integrally attached to the rotor 2 while being arranged coaxially with the rotor 2. The stator column 7 is installed between the rotor 2 and the rotor shaft 6.

An electric component 11 such as a motor 8, radial direction magnetic bearings 9 and 9 and an axial direction magnetic bearing 10 is disposed on the surface side of the stator column 7 facing the rotor shaft 6. Is configured to rotate the rotor 2 about its axis, and the radial direction magnetic bearing 9 and the axial direction magnetic bearing 10 are configured to support the rotor 2 in a fixed position by magnetic force.

The radial magnetic bearing 9 is formed of a radial sensor 9a and a radial electromagnet 9b. The radial sensor 9a detects the radial displacement of the rotor shaft 6 and The electromagnet 9b is excited based on the detection result of the radial direction sensor 9a, and the magnetic force of this excitation is configured to support the rotor 2 integrally with the rotor shaft 6 in the radial direction position.

The axial magnetic bearing 10 is formed by a thrust disk 10a integrally fixed to the outer peripheral surface of the rotor shaft 6, an axial sensor 10b, and a pair of axial electromagnets 10c, 10c facing each other via the thrust disk 10a. The axial sensor 10b is excited so as to detect the axial displacement of the rotor shaft 6, and the pair of axial electromagnets 10c, 10c are excited based on the detection result of the axial sensor 10b. It is configured to support the rotor 2 integrally with the rotor shaft 6 at a fixed position in the axial direction by the magnetic force generated by.

In such a turbo molecular pump, the casing 1, the rotor 2 and the stator column 7 are made of a metal such as aluminum or stainless steel, and the rotation of the rotor 2 causes the stator blades 3 and the rotor blades 4 to be molecularly separated. Kinetic energy is applied so that the molecules are exhausted from the intake port 1a toward the exhaust port 1b.

[0008]

[Problems to be solved by the device]

 However, in the conventional turbo molecular pump as described above, the casing 1, the rotor 2 and the stator column 7 are simply formed of aluminum, stainless steel or the like. The heat transfer due to radiation between the stator 2 and the stator column 7 is poor, so that the rotor 1 side from the casing 1 cannot be efficiently and sufficiently cooled, and time is required even when the rotor 2 side is heated from the casing 1. It takes.

Therefore, heat removal (cooling) of the rotor for the purpose of reducing gas emission during pump operation and heating of the rotor (baking work) for the purpose of removing adsorbed molecules during pump aging are effective. There is a problem that you can not do it.

In addition, as described above, when the temperature of the casing 1 is controlled to control the temperature of the rotor 2, when the temperature of the stator column 7 rises, the heat of the stator column 7 causes the rotor 2 to be heated. Since the temperature of the rotor increases, there is a problem that the temperature of the rotor cannot be controlled with high accuracy.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to effectively perform heat removal (cooling) and baking of the rotor and response speed in rotor temperature control and It is to provide a turbo molecular pump capable of improving accuracy.

[0012]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a cylindrical rotor rotatably disposed inside a casing, and a rotor alternately provided along an axis of the rotor and fixed to an inner wall surface of the casing. A rotor blade arranged on the stator blade and the outer peripheral surface of the rotor, and a magnetic bearing installed on the inner peripheral surface side of the rotor and supporting the rotor at a fixed position by magnetic force, or a motor for rotating the rotor around its axis. In a turbo molecular pump that is equipped with a stator column equipped with electrical components such as a rotor, and rotates the rotor to give kinetic energy to the molecules by the stator blades and rotor blades to exhaust molecules, the inner peripheral surface of the rotor is While a heat insulating part with a low thermal emissivity is provided on the surface of the rotor and the stator column facing it, heat transfer with a high heat emissivity is performed on the outer peripheral surface of the rotor and the inner wall surface of the casing facing it. The is characterized in that provided.

[0013]

[Action]

 According to the present invention, the heat insulating portion blocks heat transfer by radiation between the rotor and the stator column, while the heat transfer portion promotes heat transfer by radiation between the rotor and the casing.

[0014]

Embodiment An embodiment of a turbo molecular pump according to the present invention will be described below with reference to FIG.

It should be noted that the basic configuration of the turbo-molecular pump shown in the figure, for example, that a cylindrical rotor 2 is rotatably disposed inside the casing 1, and the outer peripheral surface of the rotor 2 and the casing are 1, stator blades 3 and rotor blades 4 are alternately provided along the axis of the rotor 2, and the stator blades 3 are fixed to the inner wall surface of the casing 1 via a spacer ring 5. The rotor blades 4 are arranged on the outer peripheral surface of the rotor 2, and the stator column 7 is provided on the inner peripheral surface side of the rotor 2. The stator column 7 connects the rotor 2 and the rotor shaft 6. Since it is the same as the conventional one, it has the same electrical components 11 such as the motor 8, the radial direction magnetic bearings 9 and 9 and the axial direction magnetic bearing 10 that are installed between them. Numbered with detailed explanation The description is omitted.

In this turbo molecular pump, a heat insulating portion 12 is provided on the inner peripheral surface of the rotor 2 and the surface of the status column 7 facing the inner peripheral surface of the rotor 2. The heat insulating portion 12 is a mirror finishing layer of silver or aluminum. And is set to have a low thermal emissivity.

A heat transfer section 13 is provided on the outer peripheral surface of the rotor 2 and on the inner wall surface side of the casing 1 facing the rotor 2, especially on the surface of the spacer ring 5, and the heat transfer section 13 is a ceramic layer or a carbon layer. It is formed from a black body layer, etc., and is set to have a high thermal emissivity.

The silver or aluminum mirror finishing layer forming the heat insulating portion 12 may be formed by silver or aluminum mirror finishing plating, and the ceramic layer forming the heat transfer portion 13 may be ceramic plating. It can also be created by.

Next, the operation of the turbo molecular pump configured as described above will be described with reference to FIG.

It is to be noted that the basic operation of the turbo molecular pump, that is, the rotation of the rotor 2 gives kinetic energy to the molecules by the stator blades 3 and the rotor blades 4, and the molecules are exhausted from the intake port 1a to the exhaust port 1b side as in the conventional case. Since they are similar, detailed description thereof will be omitted.

According to this turbo molecular pump, when the temperature of the stator column 7 rises, heat transfer due to radiation between the stator column 7 and the rotor 2 is blocked by the heat insulating section 12, and the stator column 7 side The heat transferred to the rotor 2 is reduced as much as possible, and the transfer of heat by radiation between the casing 1 and the rotor 2 is promoted by the heat transfer section 13. Therefore, the efficiency of cooling the rotor 2 from the casing 1 side is good.

When the casing 1 is heated to perform a so-called baking operation, the heat transfer by the radiation between the casing 1 and the rotor 2 is promoted by the heat transfer portion 13, and the efficiency of the casing 1 to the rotor 2 is increased. The heat is transmitted well. Therefore, the temperature of the rotor 2 required for the baking work can be obtained in a short time.

Even when the temperature of the casing 1 is controlled to control the temperature of the rotor 2, the heat transfer section 13 promotes the transfer of heat by radiation between the casing 1 and the rotor 2 and the casing 1 to the rotor 2. Heat is efficiently transferred to 2. Therefore, the response speed of the temperature control is fast and its accuracy is high.

Therefore, according to the turbo molecular pump of the above embodiment, the heat transfer due to radiation is blocked between the rotor and the stator column by the heat insulating section, and the heat transfer due to radiation is between the rotor and the casing due to the heat transfer section. Since it is promoted, the heat transferred from the stator column side to the rotor is reduced as much as possible, and the rotor can be efficiently cooled and heated from the casing side, which removes heat from the rotor and so-called baking. Work can be done effectively.

Further, even when the temperature of the casing is controlled to control the temperature of the rotor, the transfer of heat by radiation between the casing and the rotor is promoted by the heat transfer section as described above, and the casing is efficiently transferred to the rotor. Since heat is transferred, the temperature of the rotor can be controlled with high response speed and high accuracy.

In this embodiment, the turbo molecular pump using the magnetic bearing as the bearing of the rotor is described, but the same effect can be obtained in the turbo molecular pump using the ball bearing as the bearing and other bearings. .

[0027]

[Effect of device]

 In the turbo molecular pump according to the present invention, the heat insulating portion having a low thermal emissivity is provided on the inner peripheral surface of the rotor and the surface of the stator column facing the outer peripheral surface as described above, while the outer peripheral surface of the rotor is opposed to the heat insulating portion. Since a heat transfer part with a high thermal emissivity is provided on the inner wall surface side of the casing, the heat transfer due to radiation between the rotor and the stator column is blocked by the heat insulating part, and heat transfer due to radiation between the rotor and the casing. Since it is promoted by the heat transfer section, the heat transferred from the stator column side to the rotor is reduced as much as possible, and the rotor can be efficiently cooled and heated from the casing side, so that heat removal and , So-called baking work can be effectively performed.

Further, according to the present invention, even when the temperature of the casing is controlled to control the temperature of the rotor, the transfer of heat by radiation between the casing and the rotor is promoted by the heat transfer section as described above. Since the heat is efficiently transferred from the casing to the rotor, the temperature of the rotor can be controlled with high response speed and high accuracy.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a turbo molecular pump according to the present invention.

FIG. 2 is a sectional view of a conventional turbo molecular pump.

[Explanation of symbols]

 2 rotor 3 stator blade 4 rotor blade 7 stator column 11 electrical component 12 heat insulation section 13 heat transfer section

Claims (1)

[Scope of utility model registration request] 1. A cylindrical rotor rotatably arranged inside a casing, stator blades alternately provided along an axis of the rotor and fixed to an inner wall surface of the casing, and an outer peripheral surface of the rotor. A rotor blade disposed in the rotor, and a magnetic bearing that is installed on the inner peripheral surface side of the rotor and that supports the rotor in a fixed position by magnetic force, or an electric component such as a motor that rotates the rotor around its axis. In a turbo molecular pump that includes a column and exhausts the molecules by giving kinetic energy to the molecules by the rotation of the rotor and the stator blades and the rotor blades, the thermal emissivity of the inner peripheral surface of the rotor and the surface of the stator column facing the inner peripheral surface of the rotor. A low heat-insulating part is provided, while a heat transfer part having a high thermal emissivity is provided on the outer peripheral surface of the rotor and the inner wall surface of the casing facing the outer peripheral surface. Child pump.