Vacuum pump and vacuum pump components

Abstract

To provide a vacuum pump having more excellent mechanical characteristics.SOLUTION: A turbo molecular pump comprises a rotary blade 114 arranged on a rotor shaft, and to be rotated together with the rotor shaft, and exhausts process gas with exhaust elements (rotary turbine blades, a rotator body 103a, etc.) provided in the rotary blade by rotating the rotor shaft. The rotary blade 114 is made of a first metal material and a second metal material, and at least a portion of constituent parts is made by a 3D printer. A reinforcing material 118 that is the second metal material having higher strength than that of the first metal material constituting a main shape of the rotary blade 114 is arranged in an integral arrangement structure.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a vacuum pump such as a turbo molecular pump, and components of a vacuum pump.

Background Art

[0002] Generally, a turbo molecular pump is known as a type of vacuum pump. This turbo molecular pump is used, for example, for evacuation in manufacturing equipment such as semiconductors and flat panels. In a turbo molecular pump, by energizing a motor inside the pump body, the rotating blades are rotated, and the gas molecules (gas molecules) of the gas (process gas) sucked into the pump body are bounced off to exhaust the gas.

[0003] Also, Patent Document 1 cited below discloses that the rotor disk (66) or the stator disk (68) is manufactured by a thermal fusion lamination method, 3D printing, etc., and can be composed of two or more member layers.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in Patent Document 1, paragraph 0015 states, "These member layers can be connected to each other by lamination (lamination process, German: Laminieren). In this case, the member layers can be made individually and then joined or laminated to each other." and paragraph 0019 states, "In particular, various material combinations can be intended in the member. One region of the member can be composed of, for example, one powdered material, while another region can be composed of another powdered material. The first region of the member can be formed from, for example, aluminum, and the second region of the member can be formed from, for example, titanium. In this case, an aluminum-titanium transition (German: Uebergaenge) can be formed in the boundary region between the two regions by intermetallic bonding."

[0006] Furthermore, in Patent Document 1, paragraph 0020 states, "The members may also be formed from various powdered materials. These are combined, for example, via a buffer layer." and paragraph 0021 states, "Preferably, the members consist of at least two, in particular, laminated member layers. These layers are manufactured individually, arranged toward each other in the configuration described above, and joined together in particular by lamination."

[0007] However, Patent Document 1 only discloses joining or laminating individually manufactured member layers, and offers little flexibility in selecting the parts where mechanical strength can be improved, or in selecting the shape of those parts. Therefore, even if the manufacturing method disclosed in Patent Document 1 is adopted, there is a possibility that the mechanical properties of the parts requiring reinforcement will be insufficient.

[0008] The object of the present invention is to provide a vacuum pump and vacuum pump components having superior mechanical properties. [Means for solving the problem]

[0009] (1) In order to achieve the above objective, the vacuum pump according to the present invention It has rotor blades positioned on the rotor shaft and rotating together with the rotor shaft, A vacuum pump that exhausts gas by exhausting an exhaust element provided on the rotor blade due to the rotation of the rotor shaft, The rotor blade is made of multiple metal materials, and its constituent parts are manufactured by a fusion additive manufacturing method. A reinforcing material, which is a second metal material with higher strength than the first metal material that constitutes the main shape of the rotor blade, is arranged in an integrated structure. 、 The rotor blade comprises a cylindrical rotating body and a rotating turbine blade formed on the outer circumference of the rotating body, The reinforcing member is arranged on the rotating body. It is characterized by having this feature. (2) In order to achieve the above objective, the vacuum pump components according to the present invention are The rotor blades of the vacuum pump are configured as follows: A vacuum pump component comprising a cylindrical rotating body and rotating turbine blades formed on the outer circumference of the rotating body, It consists of multiple metal materials, and at least a portion of the constituent parts are manufactured by fused deposition modeling. At least the rotating body itself A reinforcing material, which is a second metal material with higher strength than the first metal material that constitutes the main shape, is arranged in an integrated structure. 、 The reinforcing member is arranged on the rotating body. It is characterized by having this feature. [Effects of the Invention]

[0010] According to the above invention, it is possible to provide a vacuum pump and vacuum pump components having superior mechanical properties. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram illustrating the configuration of a turbomolecular pump according to the first embodiment of the present invention. [Figure 2] This is a circuit diagram of an amplifier. [Figure 3] This is a time chart showing the control when the current command value is greater than the detected value. [Figure 4]It is a time chart showing control when the current command value is smaller than the detected value. [Figure 5] It is an explanatory diagram schematically showing the reinforced part of the rotary wing by hatching. [Figure 6] (a) is a plan view schematically showing the shape and arrangement of the reinforcing material according to the first embodiment, and (b) is a longitudinal side view showing an enlarged portion along the line A-A in (a). [Figure 7] It is an explanatory diagram schematically showing a 3D printer. [Figure 8] (a) is an explanatory diagram schematically showing the formation procedure of each layer, (b) is an explanatory diagram showing another formation procedure of each layer, and (c) is an explanatory diagram showing still another formation procedure of each layer. [Figure 9] (a) to (c) are longitudinal side views schematically showing the shape and arrangement of the reinforcing material according to the second to fourth embodiments. [Figure 10] (a) is a plan view schematically showing the shape and arrangement of the reinforcing material according to the fifth embodiment, and (b) is a longitudinal side view showing an enlarged portion along the line B-B in (a). [Figure 11] (a) is a plan view schematically showing the shape and arrangement of the reinforcing material according to the sixth embodiment, and (b) is a longitudinal side view showing an enlarged portion along the line C-C in (a). [Figure 12] It is a longitudinal side view schematically showing the reinforcing material according to the seventh embodiment.

Embodiments for Carrying Out the Invention

[0012] <Basic Configuration of the Turbo Molecular Pump 100 According to the First Embodiment> FIG. 1 shows a longitudinal sectional view of a turbo molecular pump 100 as a vacuum pump according to the first embodiment of the present invention. This turbo molecular pump 100 is adapted to be connected to a vacuum chamber (not shown) of a target device such as a semiconductor manufacturing apparatus.

[0013] In Figure 1, the turbomolecular pump 100 has an intake port 101 formed at the upper end of a cylindrical outer cylinder 127. Inside the outer cylinder 127 is a rotating body 103, which has multiple rotating turbine blades 102 (102a, 102b, 102c...) formed radially and in multiple stages around its circumference, serving as turbine blades for drawing in and exhausting gas.

[0014] In the following, the rotating turbine blades (turbine blade sections) of multiple stages may be collectively referred to as "rotating turbine blade 102". Also, when there is no need to distinguish between the rotating turbine blades (turbine blade sections) of each stage, they may be collectively referred to as "rotating turbine blade 102". Furthermore, if necessary, the rotating turbine blades (turbine blade sections) may be distinguished by stage and referred to as "rotating turbine blade 102a", "rotating turbine blade 102b", "rotating turbine blade 102c", etc. Each stage is composed of multiple blades (blade sections), similar to a typical turbomolecular pump. The same applies to the fixed turbine blades 123 (123a, 123b, 123c, etc.) and fixed blade spacers 125 (125a, 125b, 125c, etc.), which will be described later.

[0015] A rotor shaft 113 is attached to the center of the rotating body 103, and this rotor shaft 113 is suspended in the air and its position is controlled by, for example, a 5-axis controlled magnetic bearing. In this embodiment, the rotating body 103 has a rotor shaft 113, and the rotor shaft 113 and the rotor blades 114 are combined to form the rotating body 103. Details of the structure of the rotor blades 114 will be described later.

[0016] The upper radial electromagnet 104 consists of four electromagnets arranged in pairs along the X and Y axes. Four upper radial sensors 107 are provided in close proximity to the upper radial electromagnet 104, each corresponding to one of the upper radial electromagnets 104. The upper radial sensors 107 are, for example, inductance sensors or eddy current sensors with conduction windings, and detect the position of the rotor shaft 113 based on the change in the inductance of these conduction windings, which changes according to the position of the rotor shaft 113. These upper radial sensors 107 are configured to detect the radial displacement of the rotor shaft 113, i.e., the rotating body 103 fixed to it, and send the data to the control device 200.

[0017] In this control device 200, for example, a compensation circuit having a PID adjustment function generates an excitation control command signal for the upper radial electromagnet 104 based on the position signal detected by the upper radial sensor 107, and the amplifier circuit 150 (described later) shown in Figure 2 controls the excitation of the upper radial electromagnet 104 based on this excitation control command signal, thereby adjusting the upper radial position of the rotor shaft 113.

[0018] The rotor shaft 113 is made of a high-permeability material (such as iron or stainless steel) and is attracted by the magnetic force of the upper radial electromagnet 104. This adjustment is performed independently in the X-axis and Y-axis directions. The lower radial electromagnet 105 and lower radial sensor 108 are arranged in the same way as the upper radial electromagnet 104 and upper radial sensor 107, and adjust the lower radial position of the rotor shaft 113 in the same way as the upper radial position.

[0019] Furthermore, axial electromagnets 106A and 106B are positioned above and below a disc-shaped metal disk (also called an "armature disk") 111 located at the bottom of the rotor shaft 113. The metal disk 111 is made of a highly permeable material such as iron. An axial sensor 109 is provided to detect the axial displacement of the rotor shaft 113, and its axial position signal is sent to the control device 200.

[0020] Then, in the control device 200, for example, a compensation circuit having a PID adjustment function generates excitation control command signals for the axial electromagnets 106A and 106B based on the axial position signal detected by the axial sensor 109, and the amplifier circuit 150 excites the axial electromagnets 106A and 106B based on these excitation control command signals, so that the axial electromagnet 106A attracts the metal disk 111 upward with magnetic force, and the axial electromagnet 106B attracts the metal disk 111 downward, thereby adjusting the axial position of the rotor shaft 113.

[0021] Thus, the control device 200 appropriately adjusts the magnetic force exerted by the axial electromagnets 106A and 106B on the metal disk 111, causing the rotor shaft 113 to levitate axially and be held in contact with space. The amplifier circuit 150 that excites and controls the upper radial electromagnet 104, the lower radial electromagnet 105, and the axial electromagnets 106A and 106B will be described later.

[0022] On the other hand, the motor 121 is equipped with multiple magnetic poles arranged circumferentially around the rotor shaft 113. Each magnetic pole is controlled by the control device 200 to rotate the rotor shaft 113 via the electromagnetic force acting between it and the rotor shaft 113. The motor 121 also incorporates a rotational speed sensor, such as a Hall element, resolver, or encoder (not shown), and the rotational speed of the rotor shaft 113 is detected by the detection signal from this rotational speed sensor.

[0023] Furthermore, for example, a phase sensor (not shown) is attached near the lower radial sensor 108 to detect the phase of rotation of the rotor shaft 113. The control device 200 uses both the detection signals from this phase sensor and the rotational speed sensor to detect the position of the magnetic pole.

[0024] Multiple stationary turbine blades 123 (123a, 123b, 123c...) are arranged with a small gap (a predetermined interval) between them and rotating turbine blades 102 (102a, 102b, 102c...). Each of the rotating turbine blades 102 (102a, 102b, 102c...) is formed at a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113 in order to transport exhaust gas molecules downward by collision.

[0025] Similarly, the fixed turbine blades 123 are formed at a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113, and are arranged alternately with the stages of the rotating turbine blades 102 toward the inside of the outer cylinder 127. The outer ends of the fixed turbine blades 123 are supported by being fitted between a plurality of stacked fixed blade spacers 125 (125a, 125b, 125c, etc.).

[0026] The fixed-wing spacer 125 is a ring-shaped member and is made of a metal such as aluminum, iron, stainless steel, or copper, or an alloy containing these metals as components. An outer cylinder 127 is fixed to the outer circumference of the fixed-wing spacer 125 with a small gap in between. A base portion 129 is provided at the bottom of the outer cylinder 127. An exhaust port 133 is formed in the base portion 129 and communicates with the outside. Exhaust gas that enters the intake port 101 from the chamber (vacuum chamber) side and is transferred to the base portion 129 is sent to the exhaust port 133.

[0027] Furthermore, depending on the application of the turbomolecular pump 100, a threaded spacer 131 is provided between the lower part of the fixed-blade spacer 125 and the base part 129. The threaded spacer 131 is a cylindrical member made of a metal such as aluminum, copper, stainless steel, iron, or an alloy containing these metals, and has multiple helical screw grooves 131a engraved on its inner circumferential surface. The direction of the helix of the screw grooves 131a is such that when exhaust gas molecules move in the direction of rotation of the rotating body 103, these molecules are transported toward the exhaust port 133. The lower cylindrical part 103b of the rotating body hangs down from the lower part of the rotating body body 103a on which the rotating turbine blades 102 (102a, 102b, 102c...) of the rotating body 103 are formed. The outer circumferential surface of the lower cylindrical portion 103b of the rotating body is cylindrical and protrudes toward the inner circumferential surface of the threaded spacer 131, and is in close proximity to the inner circumferential surface of the threaded spacer 131 with a predetermined gap between them. The exhaust gas, which has been transferred to the threaded groove 131a by the rotating turbine blades 102 and the stationary turbine blades 123, is guided by the threaded groove 131a and sent to the base portion 129. In this way, the threaded spacer 131 and the lower cylindrical portion 103b of the rotating body opposite it constitute the Holbeck-type exhaust mechanism 204. The Holbeck-type exhaust mechanism 204 improves the exhaust characteristics of the turbomolecular pump 100 by giving direction to the exhaust gas through the rotation of the lower cylindrical portion 103b of the rotating body relative to the threaded spacer 131.

[0028] The base portion 129 is a disc-shaped component that forms the base of the turbomolecular pump 100, and is generally made of a metal such as iron, aluminum, or stainless steel. The base portion 129 not only physically holds the turbomolecular pump 100 but also functions as a heat conduction path, so it is desirable to use a metal that is rigid and has high thermal conductivity, such as iron, aluminum, or copper.

[0029] In this configuration, when the rotating turbine blades 102 are rotated together with the rotor shaft 113 by the motor 121, exhaust gas is drawn in from the chamber through the intake port 101 by the action of the rotating turbine blades 102 and the stationary turbine blades 123. The exhaust gas drawn in from the intake port 101 passes between the rotating turbine blades 102 and the stationary turbine blades 123 and is transferred to the base section 129. At this time, the temperature of the rotating turbine blades 102 rises due to frictional heat generated when the exhaust gas comes into contact with the rotating turbine blades 102 and heat conduction generated by the motor 121, but this heat is transferred to the stationary turbine blades 123 side by radiation or conduction by gas molecules of the exhaust gas.

[0030] The fixed-wing spacers 125 are joined to each other at their outer circumference, and they transmit heat received by the fixed turbine blades 123 from the rotating turbine blades 102, as well as frictional heat generated when exhaust gases come into contact with the fixed turbine blades 123, to the outside.

[0031] In the above description, the threaded spacer 131 was described as being positioned on the outer circumference of the lower cylindrical portion 103b of the rotating body 103, with a threaded groove 131a engraved on the inner surface of the threaded spacer 131. However, conversely, there are also cases where a threaded groove is engraved on the outer circumference of the lower cylindrical portion 103b of the rotating body, and a spacer having a cylindrical inner surface is positioned around it.

[0032] Furthermore, depending on the application of the turbomolecular pump 100, the electrical components, which consist of an upper radial electromagnet 104, an upper radial sensor 107, a motor 121, a lower radial electromagnet 105, a lower radial sensor 108, axial electromagnets 106A, 106B, and an axial sensor 109, may be covered by a stator column 122 to prevent the gas drawn in from the intake port 101 from entering the electrical components, and the inside of this stator column 122 may be maintained at a predetermined pressure with purge gas.

[0033] In this case, a purge gas introduction pipe (also called a "purge gas port") 132 is provided in the base section 129, and purge gas is introduced through this pipe. The introduced purge gas is sent to the exhaust port 133 through the gap between the protective bearing 120 and the rotor shaft 113, between the rotor and stator of the motor 121, and between the inner cylindrical part of the rotating turbine blade 102 (lower cylindrical part of the rotating body 103b) and the stator column 122 or the base section 129.

[0034] Here, the turbomolecular pump 100 requires model identification and control based on individually adjusted unique parameters (e.g., characteristics corresponding to the model). To store these control parameters, the turbomolecular pump 100 is equipped with an electronic circuit section 141 within its body. The electronic circuit section 141 consists of electronic components such as semiconductor memory such as EEP-ROM and semiconductor elements for accessing it, and a substrate 143 for mounting them. This electronic circuit section 141 is housed, for example, below a rotational speed sensor (not shown) near the center of the base section 129 that constitutes the lower part of the turbomolecular pump 100, and is closed by an airtight bottom cover 145.

[0035] Incidentally, in the semiconductor manufacturing process, some process gases introduced into the chamber have the property of becoming solid when their pressure exceeds a predetermined value or their temperature falls below a predetermined value. Inside the turbomolecular pump 100, the exhaust gas pressure is lowest at the intake port 101 and highest at the exhaust port 133. If the process gas pressure exceeds a predetermined value or its temperature falls below a predetermined value while it is being transferred from the intake port 101 to the exhaust port 133, the process gas becomes solid and adheres to and accumulates inside the turbomolecular pump 100.

[0036] For example, if SiCl4 is used as the process gas in an Al etching apparatus, the low vacuum (760 [torr] ~ 10 -2The vapor pressure curve shows that when the pressure is low (torr) and the temperature is low (approximately 20°C), solid products (e.g., AlCl3) precipitate and adhere to the inside of the turbomolecular pump 100. As a result, when precipitates of process gas accumulate inside the turbomolecular pump 100, these deposits narrow the pump flow path, causing a decrease in the performance of the turbomolecular pump 100. Furthermore, the aforementioned products were prone to solidifying and adhering in areas of high pressure, such as near the exhaust port 133 and near the threaded spacer 131.

[0037] Therefore, in order to solve this problem, conventional methods have involved wrapping a heater (not shown) or an annular water-cooling pipe 149 around the outer circumference of the base portion 129, and embedding a temperature sensor (e.g., a thermistor) (not shown) in the base portion 129. Based on the signal from this temperature sensor, heating by the heater and cooling by the water-cooling pipe 149 are controlled (hereinafter referred to as TMS; Temperature Management System) to maintain the temperature of the base portion 129 at a constant high temperature (set temperature). In this embodiment, the threaded spacer 131 is heated by a heater (not shown) embedded in the threaded spacer 131, and the base portion 129 is cooled by a water-cooling pipe 149 embedded in the bottom cover 145.

[0038] Next, we will describe an amplifier circuit 150 that energizes and controls the upper radial electromagnet 104, the lower radial electromagnet 105, and the axial electromagnets 106A and 106B of the turbomolecular pump 100 configured in this way. The circuit diagram of this amplifier circuit is shown in Figure 2.

[0039] In Figure 2, the electromagnet winding 151, which constitutes the upper radial electromagnet 104, has one end connected to the positive terminal 171a of the power supply 171 via transistor 161, and the other end connected to the negative terminal 171b of the power supply 171 via current detection circuit 181 and transistor 162. Transistors 161 and 162 are so-called power MOSFETs, and have a structure in which a diode is connected between their source and drain.

[0040] In this configuration, transistor 161 has its diode cathode terminal 161a connected to the positive terminal 171a, and its anode terminal 161b connected to one end of the electromagnet winding 151. Transistor 162 has its diode cathode terminal 162a connected to the current detection circuit 181, and its anode terminal 162b connected to the negative terminal 171b.

[0041] On the other hand, the diode 165 for current regeneration has its cathode terminal 165a connected to one end of the electromagnet winding 151, and its anode terminal 165b connected to the negative terminal 171b. Similarly, the diode 166 for current regeneration has its cathode terminal 166a connected to the positive terminal 171a, and its anode terminal 166b connected to the other end of the electromagnet winding 151 via the current detection circuit 181. The current detection circuit 181 is composed of, for example, a Hall sensor type current sensor or an electrical resistance element.

[0042] The amplifier circuit 150 configured as described above corresponds to one electromagnet. Therefore, if the magnetic bearing is 5-axis controlled and there are a total of 10 electromagnets 104, 105, 106A, and 106B, a similar amplifier circuit 150 is configured for each electromagnet, and the 10 amplifier circuits 150 are connected in parallel to the power supply 171.

[0043] Furthermore, the amplifier control circuit 191 is configured, for example, by a digital signal processor (hereinafter referred to as the DSP section) of the control device 200 (not shown), and this amplifier control circuit 191 is configured to switch transistors 161 and 162 on and off.

[0044] The amplifier control circuit 191 compares the current value detected by the current detection circuit 181 (the signal reflecting this current value is called the current detection signal 191c) with a predetermined current command value. Based on this comparison, it determines the magnitude of the pulse width (pulse width time Tp1, Tp2) to be generated within the control cycle Ts, which is one period of PWM control. As a result, gate drive signals 191a and 191b with this pulse width are output from the amplifier control circuit 191 to the gate terminals of transistors 161 and 162.

[0045] Furthermore, when the rotating body 103 passes a resonance point during accelerated rotational speed operation, or when disturbances occur during constant-speed operation, it is necessary to control the position of the rotating body 103 with high speed and strong force. For this reason, a high voltage of, for example, 50V is used as the power supply 171 so that the current flowing through the electromagnet winding 151 can be rapidly increased (or decreased). In addition, a capacitor is usually connected between the positive electrode 171a and the negative electrode 171b of the power supply 171 to stabilize the power supply 171 (not shown).

[0046] In this configuration, when both transistors 161 and 162 are turned on, the current flowing through the electromagnet winding 151 (hereinafter referred to as the electromagnet current iL) increases, and when both are turned off, the electromagnet current iL decreases.

[0047] Furthermore, by turning one of transistors 161 and 162 on and the other off, a so-called flywheel current is maintained. By allowing this flywheel current to flow through the amplifier circuit 150, hysteresis loss in the amplifier circuit 150 can be reduced, and the overall power consumption of the circuit can be kept low. In addition, by controlling transistors 161 and 162 in this way, high-frequency noise such as harmonics generated in the turbomolecular pump 100 can be reduced. Moreover, by measuring this flywheel current with the current detection circuit 181, the electromagnet current iL flowing through the electromagnet winding 151 can be detected.

[0048] In other words, if the detected current value is smaller than the current command value, both transistors 161 and 162 are turned on only once during the control cycle Ts (e.g., 100 μs) for a duration corresponding to the pulse width time Tp1, as shown in Figure 3. Therefore, the electromagnet current iL during this period increases from the positive electrode 171a to the negative electrode 171b, towards the current value iLmax (not shown) that can flow through transistors 161 and 162.

[0049] On the other hand, if the detected current value is greater than the current command value, both transistors 161 and 162 are turned off only once during the control cycle Ts for a duration corresponding to the pulse width time Tp2, as shown in Figure 4. Therefore, during this period, the electromagnet current iL decreases from the negative electrode 171b towards the positive electrode 171a, towards a regenerative current value iLmin (not shown) via diodes 165 and 166.

[0050] In either case, after the pulse width time Tp1 and Tp2 have elapsed, one of transistors 161 or 162 is turned on. Therefore, during this period, the flywheel current is maintained in the amplifier circuit 150.

[0051] The turbomolecular pump 100, having this basic configuration, has an intake section on the upper side (the side with the intake port 101) in Figure 1 that connects to the target equipment, and an exhaust section on the lower side (the side where the exhaust port 15, which constitutes the exhaust port 133, is provided on the base portion 129 so that it protrudes to the right in the figure) that connects to an auxiliary pump (back pump), etc., which is not shown. Furthermore, the turbomolecular pump 100 can be used not only in the vertical position shown in Figure 1, but also in an inverted position, a horizontal position, and an inclined position.

[0052] Furthermore, in the turbomolecular pump 100, the aforementioned outer cylinder 127 and base portion 129 are combined to form a single case. In the following, both the outer cylinder 127 and base portion 129 may be collectively referred to as the "casing" or "main casing." Alternatively, the outer cylinder 127 or the base portion 129 may be referred to as the "casing" alone. The turbomolecular pump 100 is electrically (and structurally) connected to a box-shaped electrical case (not shown), and the aforementioned control device 200 is incorporated into the electrical case.

[0053] The internal structure of the main casing of the turbomolecular pump 100 (here, a combination of the outer cylinder 127 and the base part 129) can be divided into a rotating mechanism part 136 that rotates the rotor shaft 113 etc. by the motor 121, and an exhaust mechanism part 137 that is rotationally driven by the rotating mechanism part 136. Furthermore, the exhaust mechanism part 137 can be considered as being divided into a turbomolecular pump mechanism part (turbomolecular pump part) 138 composed of rotating turbine blades 102 and fixed turbine blades 123 etc., and a screw-groove pump mechanism part (Holbeck-type exhaust mechanism part 204) composed of the lower cylindrical part 103b of the rotating body and threaded spacer 131 etc.

[0054] Furthermore, the aforementioned purge gas (protective gas) is used to protect the bearing parts and the rotating turbine blades 102, preventing corrosion caused by exhaust gas (process gas) and cooling the rotating turbine blades 102. This purge gas can be supplied using conventional methods.

[0055] For example, the aforementioned purge gas port 132, which extends linearly in the radial direction, is provided at a predetermined location on the base portion 129 (such as at a position 90 or 120 degrees away from the exhaust port 133). Purge gas is then supplied to this purge gas port 132 from the outside of the base portion 129 via a purge gas cylinder (such as an N2 gas cylinder) or a flow regulator (valve device).

[0056] The aforementioned protective bearing 120 is also called a "touchdown (T / D) bearing" or "backup bearing." These protective bearings 120 prevent the rotor shaft 113 from changing position or orientation significantly, and thus prevent damage to the rotating turbine blades 102 and their surrounding areas, even in the event of problems such as electrical system failure or atmospheric intrusion.

[0057] Note that in Figure 1, which shows the structure of the turbomolecular pump 100 and the rotating body 103, the hatching indicating the cross-section of the parts has been omitted to avoid making the drawing too complex.

[0058] <Configuration of the rotor blade 114> As mentioned above, the rotor blade 114 is combined with the rotor shaft 113 and rotates together with the rotor shaft 113. The rotor blade 114 has a rotating body 103a and a lower cylindrical part 103b of the rotating body, and a number of rotating turbine blades 102 (102a, 102b, 102c, etc.) are integrally formed on the rotating body 103a. Then, due to the rotation of the rotor shaft 113, gas (exhaust gas, process gas) is exhausted by the exhaust element 116 provided on the rotor blade 114.

[0059] The exhaust element 116 provided on the rotor blade 114 includes parts or components of the rotor blade 114 that are in contact with gas (exhaust gas, process gas) and directly involved in exhaust. Specifically, the exhaust element 116 includes, for example, the rotor blades 102 (102a, 102b, 102c...), the rotor body 103a, and the lower cylindrical part 103b of the rotor body.

[0060] The rotor blade 114 is made of multiple metal materials, and its constituent parts (components, parts that make up the rotor blade 114) are manufactured by fusion additive manufacturing. Furthermore, in the rotor blade 114, a reinforcing material 118 (described later, Figures 6(a) and (b)), which is a metal material with higher strength than the metal material that constitutes the main shape of the rotor blade 114, is arranged in an integrated structure. Hereafter, the metal material that constitutes the main shape of the rotor blade 114 may be referred to as the "first metal material" or "main material," and the metal material of the reinforcing material 118 may be referred to as the "second metal material" or "high-strength material."

[0061] In this embodiment, the reinforcing member 118 is positioned in the region from the rotating body 103a of the rotor blade 114 to the lower cylindrical portion 103b of the rotating body. Figure 5 schematically illustrates this. In Figure 5, only the region 119 where the reinforcing member 118 is to be placed (placement target region) is hatched.

[0062] The placement area 119 is not limited to the range shown in Figure 5. The placement area 119 may be narrower than the range shown in Figure 5, or it may be wider than the range shown in Figure 5. The placement area 119 may extend into the interior of the rotating turbine blades 102 (102a, 102b, 102c...) or be limited to the interior of the rotating turbine blades 102 (102a, 102b, 102c...).

[0063] The "main shape" of the rotor blade 114 refers, for example, to the outer shape that forms the outer shape of the rotor blade 114. The "outer shape of the rotor blade 114" refers, for example, to the shape that defines the appearance of the rotor blade 114 when it is completed. As an example of an embodiment, when a reinforcing member 118 (described later) is arranged inside the rotor blade 114 in an integrated arrangement structure (described later), the "main shape" of the rotor blade 114 can also be said to be the shape exposed on the outside of the reinforcing member 118.

[0064] The high-strength material (second metallic material) used as reinforcing material 118 is a metallic material with greater strength (such as tensile strength) than the main material (first metallic material) used in the "main shape" part. Furthermore, the high-strength material can be a metallic material with a lower coefficient of thermal expansion or a lower specific gravity than the main material.

[0065] For example, it is possible to use aluminum (usually an aluminum alloy) as the main material and stainless steel (usually a stainless steel alloy) as the high-strength material.

[0066] In addition to the combination of aluminum as the main material (first metal material) and stainless steel as the high-strength material (second metal material), various other combinations can be used. For example, it is possible to use an aluminum alloy as the main material and a magnesium alloy as the high-strength material. It is also possible to use an aluminum alloy or magnesium alloy as the main material and a titanium alloy or nickel alloy as the high-strength material. Furthermore, for example, it is possible to use an aluminum alloy or magnesium alloy as the main material and a stainless steel alloy with a high strength-to-weight ratio, such as SUS630, as the high-strength material. Furthermore, by focusing on the specific gravity of the materials, for example, it is possible to use a metal material with a relatively low specific gravity (and density) for the rotating turbine blade 102, and a metal material with a relatively high specific gravity for the rotating body 103a (and / or the lower cylindrical part 103b of the rotating body). In this way, a weight distribution is obtained for the rotating blade 114 in which the specific gravity is lighter in the radially outer part and heavier in the inner part. In addition, a structure is obtained in which the tensile strength of the root part supporting the rotating turbine blade 102 (in this case, the rotating body 103a) is stronger than that of the rotating turbine blade 102. Moreover, compared to the case in which a metal material with a high specific gravity is used on the radially outer part and a heavy metal material is used on the inner part, the forces acting in the centrifugal and downward directions are reduced, making it easier to maintain the bond between the materials. Furthermore, this is not the only option; for example, it is possible to deliberately use a heavier metal material on the radially outer side and a heavier metal material on the inner side. In this way, the relationship between specific gravities can be changed depending on which mechanical properties are prioritized.

[0067] Figure 6(a) schematically shows the rotating body 103a (or the lower cylindrical part 103b) of the rotor blade 114 cut perpendicular to the axial direction (radially). In the example in Figure 6(a), the reinforcing members 118 are arranged in an annular shape along the cylindrical shape of the rotating body 103a (or the lower cylindrical part 103b). Furthermore, in the example in Figure 6(a), the reinforcing members 118 are arranged in three concentric layers in the radial direction of the rotating body 103a (and / or the lower cylindrical part 103b). In Figure 6(a), the reinforcing members 118 are arranged from the inside in the order of the first reinforcing member 118A, the second reinforcing member 118B, and the third reinforcing member 118C. The first reinforcing member 118A has the smallest diameter, and the third reinforcing member 118C has the largest diameter.

[0068] Figure 6(b) shows a longitudinal section along line AA in Figure 6(a). In the example in Figure 6(b), the first reinforcing members 118A to the third reinforcing members 118C are arranged parallel to each other and extend linearly along the axial direction of the rotor blade 114. Here, in Figures 6(a) and (b), hatching is applied only to the reinforcing members 118 (first reinforcing members 118A to third reinforcing members 118C) for emphasis.

[0069] As shown in Figures 6(a) and (b), the reinforcing members 118 are arranged in an internal structure. An "internal structure" means a structure in which reinforcing members 118 (here, the first reinforcing member 118A to the third reinforcing member 118C) made of a high-strength material (second metal material) are embedded inside the "main shape" part made of the main material (first metal material). In the example in Figures 6(a) and (b), the reinforcing members 118 are arranged in an internal structure within the main material (first metal material) via an "integrated arrangement structure" with the "main shape" part. The reinforcing members 118 are tightly bonded to the "main shape" part without creating any gaps.

[0070] As mentioned above, the multiple metal materials include multiple metal materials with different strengths. Furthermore, the multiple metal materials include multiple metal materials with different coefficients of linear expansion. In addition, the multiple metal materials include multiple metal materials with different specific gravities. An example of a combination of metal materials that satisfies these relationships is aluminum and stainless steel. The reinforcing material 118 is arranged in the rotating body 103a (on the rotor blades) so as to be continuous in the circumferential direction (ring-shaped). It can also be said that the reinforcing material 118 is arranged in the rotating body 103a (on the rotor blades 114) so ​​as to be continuous in the rotor axis direction (the axis direction of the rotor axis 113). In this way, because the reinforcing members 118 are continuously arranged in the circumferential and radial directions, when circumferential or radial loads are generated on the rotor blade 114 due to thermal expansion, centrifugal force, etc., the reinforcing members 118 can be fully utilized, and deformation of the rotor blade 114 can be effectively suppressed. Furthermore, because the reinforcing members 118 are arranged continuously in the axial direction, they can fully exert their effect, just as they can when arranged continuously in the circumferential or radial direction, and deformation of the rotor blades 114 can be effectively suppressed.

[0071] Such "integrated arrangement structures" (and "built-in structures") are formed by fused deposition modeling (FDM). Examples of FDM means include 3D printers that melt and layer materials to form structures. 3D printers create three-dimensional structures based on digital models containing three-dimensional information. 3D printers are also called additive manufacturing devices, additive manufacturing devices, or AM (Additive Manufacturing) machines.

[0072] <An example of the 3D printer 280> Any 3D printer capable of forming an "integrated arrangement structure" (and "built-in structure") using multiple metal materials can be used as the 3D printer according to this embodiment. An example of a suitable 3D printer method is the FDM (Fused Deposition Modeling, registered trademark) method (also known as the FFF (Fused Filament Fabrication) method).

[0073] Figure 7 schematically shows the basic configuration (one example) of a 3D printer (3D modeling device) 280 using the FDM method. The 3D printer 280 is equipped with a first filament supply unit 282A and a second filament supply unit 282B (not shown). In Figure 7, only the first filament supply unit 282A is shown, and the second filament supply unit 282B is hidden behind the first filament supply unit 282A. A first filament 284A containing a binder is dispensed from the first filament supply unit 282A. A second filament 284B containing a binder is dispensed from the second filament supply unit 282B (not shown).

[0074] The 3D printer 280 extrudes the first filament 284A from the first head unit 286A while melting it with heat, building up layers to create a three-dimensional object. The bonding of the printing materials is done by using a heat source to melt the first filament 284A, which contains a binder.

[0075] The 3D printer 280 is equipped with a second print head 286B, and the print head used can be switched from the first print head 286A to the second print head 286B as needed. Furthermore, the 3D printer 280 may also switch the print head used from the second print head 286B to the first print head 286A.

[0076] The 3D printer 280 extrudes the second filament 284B from the second head unit 286B while melting it with heat, similar to the first filament 284A, and builds up each layer to create a three-dimensional object. The bonding of the printing materials is done by using a heat source to melt the second filament 284B, which contains a binder.

[0077] The 3D printer 280 is equipped with a table section 278 that can be raised and lowered in the Z-axis direction, and printing is performed on the table section 278. As printing progresses, the table section 278 lowers, allowing it to maintain or adjust the distance between itself and the first head section 286A and the second head section 286B.

[0078] The first head unit 286A and the second head unit 286B are individually supplied with a first filament 284A and a second filament 284B, each made of a different type of metal material. The first filament 284A (or the second filament 284B) used for printing is guided to the printing position, and 3D printing is performed using a metal filament (first filament 284A or second filament 284B) appropriate to the part of the object to be printed (in this case, the rotor blade 114). For example, it is possible to use aluminum for the metal material of the first filament 284A and stainless steel for the metal material of the second filament 284B.

[0079] The first head unit 286A and the second head unit 286B are guided by the drive mechanism 238 and move together as a single unit. For example, when fabricating an "integrated arrangement structure" as shown in the example in Figure 6(b), it is possible to layer metal materials in the order schematically shown in Figure 8(a). In this case, the first head unit 286A (and the second head unit 286B) are scanned by the 3D printer 280 in the direction indicated by arrow A, for example. In the example in Figure 8(a), the part that will become the rotating body 103a (the part that constitutes the "main shape") 218A is formed first, and then the part that will become the reinforcing material 118 218B is formed as part of the same layer (lower layer) 218.

[0080] When forming the next layer (upper layer) 219, the first head portion 286A (and the second head portion 286B) is scanned again, for example, in the direction indicated by arrow A. Then, the portion 219A that will become the rotating body 103a is formed first, and then, as part of the same layer (upper layer 219), the portion 219B that will become the reinforcing material 118 is formed. In this case, the portion 219A (or portion 219B) of the same metal material in the upper layer 219 is laminated on top of the portion 218A (or portion 218B) of the lower layer 218.

[0081] Furthermore, depending on the part being fabricated, the position of the end (the end in the scanning direction) of part 218A (or part 218B) in the lower layer 218 and the position of the end (the end in the scanning direction) of part 219A (or part 219B) in the upper layer 219 may be different (they may be shifted in the scanning direction).

[0082] Alternatively, the first head portion 286A (and the second head portion 286B) may be scanned in the direction indicated by arrow B. In this case, the portion 218B that will become the reinforcing member 118 in the lower layer 218 is formed first, and then the portion 218A that will become the rotating body 103a (the portion that constitutes the "main shape") is formed. Similarly, when forming the upper layer 219, the portion 219B that will become the reinforcing member 118 is formed first, and then the portion 219A that will become the rotating body 103a is formed.

[0083] Furthermore, the scanning direction of the first head unit 286A (and the second head unit 286B) may differ between the lower layer 218 and the upper layer 219. For example, when forming the lower layer 218, the first head unit 286A (and the second head unit 286B) may be scanned in the direction indicated by arrow B, and when forming the upper layer 219, the first head unit 286A (and the second head unit 286B) may be scanned in the direction indicated by arrow A.

[0084] Furthermore, depending on the part of the rotor blade 114, it is also possible to create a shape as schematically shown in Figure 8(b). In the example in Figure 8(b), the first head portion 286A (and the second head portion 286B) of the lower layer 220 is scanned in the direction indicated by arrow A, and the portion 220A that will become the rotating body 103a (the portion that constitutes the "main shape") is formed. Subsequently, in the upper layer 221, the first head portion 286A (and the second head portion 286B) is scanned in the same direction indicated by arrow A, and the portion 221A that will become the rotating body 103a and the portion 221B that will become the reinforcing member 118 are formed in order.

[0085] Here, in Figure 8(b), as in the example in Figure 8(a), it is possible to set the scanning direction of the first head unit 286A (and the second head unit 286B) to the direction of arrow B, or to alternately change the scanning direction for each layer.

[0086] Furthermore, depending on the part of the rotor blade 114, it is also possible to create a shape as schematically shown in Figure 8(c). In the example in Figure 8(c), a part 222A1 which will become the rotating body 103a (the part that constitutes the "main shape") is formed as part of one layer 222, and then a part 222B1 which will become the reinforcing member 118 is formed as part of the same layer 222. Subsequently, a part 222A2 which will become the rotating body 103a is formed as part of the same layer 222, and then a part 222B2 which will become the reinforcing member 118 is formed as part of the same layer 222.

[0087] In the 3D printer 280, by appropriately combining layers as shown in some examples in Figures 8(a) to (c), it becomes possible to form a gapless "integrated arrangement structure" (and "built-in structure") according to this embodiment.

[0088] The 3D printer 280 can be equipped with the following features. For example, the 3D printer 280 is equipped with a drive mechanism that guides the first head 286A and the second head 286B with high positioning accuracy. The drive mechanism that guides the first head 286A and the second head 286B includes, although not shown in the diagram, a stepping motor with an encoder or a linear guide. In this way, when switching between the first filament 284A and the second filament 284B, or when replacing the first filament 284A (or the second filament 284B), it is possible to continue printing on the previously printed part with high accuracy.

[0089] Furthermore, the 3D printer 280 can be equipped with a table heater (notation omitted) capable of raising the temperature of the table section 278. In this case, the table section 278 can be raised to a predetermined temperature (for example, 100°C or higher). By appropriately raising the temperature of the table section 278, the temperature difference between the material (printed object) and the table section 278 can be reduced, preventing the printed object from shrinking excessively due to a temperature drop.

[0090] Furthermore, a material with sufficient thermal conductivity (for example, aluminum) can be used for the table portion 278. In addition, the table portion 278 can be made by attaching a sheet with appropriately fine irregularities to its surface to improve the adhesion of the printed object. The irregularities of the sheet allow for a larger contact area between the printed object and the table portion 278, thereby preventing deformation of the printed object.

[0091] Furthermore, the 3D printer 280 can be equipped with an internal heater (notation omitted) that can raise the temperature inside the chamber (the space where the printing takes place) to a predetermined temperature (for example, around 70°C or higher). By raising the temperature inside the chamber, it is possible to prevent the printed object from shrinking excessively due to a drop in temperature.

[0092] Furthermore, regarding the bonding of the materials layered by the 3D printer 280, it is also possible to sinter the solidified workpiece using a binder.

[0093] <Details of the integrated arrangement structure> The "integrated arrangement structure" (and "built-in structure") described above includes structures in which a part made of one metal material is arranged relative to a part made of one metal material, and structures in which a part made of one metal material and a part made of the other metal material are integrally joined. Furthermore, the "built-in structure" is a structure in which the reinforcing member 118 is built into (or arranged in) the members that constitute the main shape (in this case, the members that constitute the shape of the outer part of the rotating body body 103a and the lower cylindrical part 103b of the rotating body, and the first metal material). The "integrally joined structure" as used here includes embodiments in which multiple metal materials form a mechanical joint structure. The "mechanical joint structure" as used here means, for example, an embodiment in which multiple metal materials are joined without using mechanical fasteners such as bolts. Furthermore, the "integrated arrangement structure" can be placed on the outer or inner circumferential surfaces of the main component, and its position is not limited to the surface or internal structure.

[0094] Generally, methods of joining metallic materials are broadly classified into mechanical bonding, material bonding, and chemical bonding. Of these, mechanical bonding includes bolting, riveting, shrink fitting, cold fitting, and crimping. Material bonding includes fusion welding, resistance welding, solid-state welding, diffusion bonding, brazing (soldering), pressure welding, friction bonding, sintering, and casting. Chemical bonding includes adhesive bonding, plating, and vapor deposition.

[0095] The "mechanical bonding structure" in this embodiment is a bonding structure produced by a fusion additive manufacturing means such as a 3D printer, and is not classified as a bonding method using mechanical fasteners such as bolts or rivets. Based on the inventors' knowledge, the bonding method according to this embodiment is a bonding method that has the characteristics of both mechanical bonding and material bonding, and therefore the term "integrated arrangement structure" is used in this specification.

[0096] <Comparison of the technology according to this embodiment with the prior art> As described above, the turbomolecular pump 100 of this embodiment has the following advantages compared to the conventional technology (described later): the reinforcing material 118, which is a metal material (second metal material) with higher strength than the metal material (first metal material) that constitutes the main shape of the rotor blade 114, is arranged in an "integrated arrangement structure".

[0097] As prior art, in addition to the aforementioned Patent Document 1, for example, Japanese Patent Application Publication No. 2005-180265 can be cited.

[0098] Japanese Patent Publication No. 2005-180265 (paragraphs 0015, 0043, etc.) discloses that "...reinforcement fibers are loaded inside the pump components that make up the vacuum pump" and that "the die-casting method shown in Figure 2b can be used in the exterior material molding process."

[0099] As in the invention disclosed in Japanese Patent Publication No. 2005-180265, when casting, it is not easy to obtain the desired dimensions (expected dimensions, designed dimensions) because the parts expand due to heat during casting. Furthermore, when dissimilar metals are cast and then shrink, it is anticipated that gaps may form at the interface due to differences in thermal expansion coefficients. Moreover, if the melting points of each component are close, the component to be cast may also melt, so the combination is limited to metals with sufficiently large differences in melting points. Furthermore, since the material is heated to a high temperature during casting, the effect of heat treatment during material manufacturing is diminished, and the material strength may decrease.

[0100] Furthermore, as disclosed in Japanese Patent Publication No. 2005-180265, when reinforcing the rotor by inserting high-strength fibers, die-casting is employed to form the outer material (the main material in this application) surrounding the fibers. However, if this method is used for the entire rotor, it is necessary to first process the fiber material into the rotor shape, which requires many steps. In addition, if the outer material is not formed with a uniform thickness, the weight distribution may become unbalanced.

[0101] In contrast to the aforementioned conventional technology, the turbomolecular pump 100 of this embodiment allows for the production of the rotor blade 114 integrated with the reinforcing material 118 using a 3D printer. This eliminates the need to pre-disassemble and manufacture each part, even when combining two or more materials (metal materials), thus eliminating (or simplifying) the assembly of parts. Furthermore, in the turbomolecular pump 100 of this embodiment, reinforcement using dissimilar materials (dissimilar metal materials) is also performed by an "integrated arrangement structure," which also eliminates (or simplifies) the need for assembly. This makes it possible to easily perform partial reinforcement of the rotor blade 114.

[0102] Furthermore, with the turbomolecular pump 100 of this embodiment, since the entire rotor blade 114 is manufactured as a single unit by 3D printing, various problems of conventional technologies such as bolting, shrink fitting, and casting when assembling dissimilar materials are eliminated. In addition, by adopting an internal structure as one of the "integrated arrangement structures," parts can be firmly joined and fixed without the need for troublesome assembly work. Moreover, the "integrated arrangement structure" and "internal structure" make it possible to change and optimize the strength of the rotor blade 114 overall or partially. And it becomes possible to manufacture such rotor blades 114 in a continuous and accurate manner.

[0103] Furthermore, because the 3D printer 280 forms an "integrated arrangement structure," it is possible to prevent gaps from forming between the metal material (first metal material) that constitutes the main shape of the rotor blade 114 and the reinforcing material 118, which is a stronger metal material (second metal material), and the two metal materials can be joined in close contact. Therefore, it is possible to firmly join the parts formed by different metal materials. Moreover, because the fabrication is performed by the 3D printer 280, even if a metal material that is relatively difficult to process with cutting tools (for example, stainless steel or titanium) is used as the second metal material (or first metal material), the difficulty of processing does not have a significant impact. For this reason, the rotor blade 114 can be easily formed regardless of the selected material.

[0104] The main shape components and the reinforcing material 118 may be fabricated using the 3D printer 280 only for a portion of the rotor blade 114 (for example, the rotating body 103a, the lower cylindrical portion 103b of the rotating body, and the rotating turbine blade 102). Furthermore, the reinforcing material 118 may be formed only inside the rotating turbine blade 102, or spanning both the rotating body 103a and the rotating turbine blade 102. If the reinforcing material 118 is formed spanning both the rotating body 103a and the rotating turbine blade 102, the bonding strength between the rotating turbine blade 102 and the rotating body 103a at the root portion (base end) can be improved.

[0105] Here, the cylindrical parts such as the rotating body body 103a and the lower cylindrical part 103b of the rotating body deform outward due to centrifugal force as the rotor blades 114 rotate. Therefore, as shown in the examples in Figures 6(a) and (b), by arranging the reinforcing members 118 in the circumferential direction, the generated load can be efficiently borne by the reinforcing members 118, enabling effective reinforcement of the rotor blades 114.

[0106] Furthermore, when reinforcing members 118 are built into the rotating turbine blade 102, the reinforcing members 118 can be positioned (oriented) in an oblique or curved manner, following the curved or cross-sectional shape of the rotating turbine blade 102. In this way, it becomes possible to effectively reinforce the rotating turbine blade 102, which has a complex shape and is subjected to loads in multiple directions (including twisting and lifting directions), in accordance with its shape and the direction of the loads.

[0107] Furthermore, the shape and arrangement of the reinforcing members 118 are not limited to the structures shown in Figures 6(a) and (b), and various structures and arrangements can be adopted. For example, in the examples of Figures 6(a) and (b), cylindrical reinforcing members 118A to 118C were arranged in three layers. In contrast, in the example of Figure 9(a) (second embodiment), the reinforcing member 318 is formed in a linear shape and extends in an annular manner in the circumferential direction of the rotating body 103a. Moreover, there are four or more reinforcing members 318, and the cross-sectional shape of each reinforcing member 318 is perfectly circular. Furthermore, the numerous reinforcing members 318 are arranged in a staggered (oblique) pattern.

[0108] In the example shown in Figure 9(b) (third embodiment), the reinforcing members 328 are formed linearly, similar to the example in Figure 9(a), and extend in an annular shape in the circumferential direction of the rotating body 103a. Furthermore, there are four or more reinforcing members 328. The cross-sectional shape of each individual reinforcing member 328 is rectangular (in this case, square), and the arrangement (configuration) of the numerous reinforcing members 328 is matrix-like.

[0109] In the example shown in Figure 9(c) (fourth embodiment), the reinforcing members 338 are formed linearly, similar to the examples in Figures 9(a) and (b), and extend in an annular shape in the circumferential direction of the rotating body 103a. Furthermore, there are four or more reinforcing members 328. The cross-sectional shape of each individual reinforcing member 338 is rhomboid, and the arrangement (arrangement) of the numerous reinforcing members 338 is staggered (oblique).

[0110] In the example shown in Figures 10(a) and (b) (Fifth Embodiment), multiple (eight in this case) annular reinforcing members 348 are arranged inside the cylindrical rotating body 103a (or the lower cylindrical part 103b of the rotating body) substantially parallel to the axial direction of the rotor blade 114 and at substantially equal intervals.

[0111] In the example shown in Figures 11(a) and (b) (sixth embodiment), the second metal material constituting the reinforcing material 358 is distributed and partially mixed in the rotor blade 114. Specifically, there are areas where the second metal material constituting the reinforcing material 358 is mixed with the first metal material, which is the main material, and the content (and concentration) of the second metal material decreases as you move from the inner circumference to the outer circumference of the rotor blade 114. In contrast, the content (and concentration) of the first metal material, which is the main material, increases as you move from the inner circumference to the outer circumference of the rotor blade 114. In Figures 11(a) and (b), this is represented by a gradient between light and dark grayscale colors. However, the invention is not limited to this, and for example, the content (and concentration) of the second metal material may be increased as you move from the inner circumference to the outer circumference of the rotor blade 114, and the content (and concentration) of the first metal material may be decreased as you move from the inner circumference to the outer circumference of the rotor blade 114.

[0112] These types of structures can be described as structures in which the composition of a metallic material gradually changes (also called material structure, molecular structure, etc.).

[0113] One method for distributing metallic materials as shown in the examples in Figures 11(a) and (b) is to diffuse the first metallic material (or the second metallic material) into the second metallic material (or the first metallic material) to bond the two materials together.

[0114] Next, in the example shown in Figure 12 (seventh embodiment), a distribution of metallic material is carried out between the rotating body 103a and the rotating turbine blades 102a. In the example shown in Figure 12, the content (and concentration) of the first metallic material in the rotating body 103a gradually increases from the rotating body 103a to the rotating turbine blades 102a, while the content (and concentration) of the second metallic material (which constitutes the reinforcing material 368) in the rotating turbine blades 102a gradually decreases. In the example shown in Figure 12, this is represented by a grayscale gradient from light to dark. Furthermore, in the example shown in Figure 12, the first metal material is also used in the formation of the rotating body 103a, and the concentration of the second metal material gradually decreases from the inner circumference to the outer circumference of the rotating body 103a, and further to the rotating turbine blade 102a. However, the rotating body 103a may be formed from the second metal material, and the concentration of the second metal material may gradually decrease from the base end to the tip end of the rotating turbine blade 102a. However, the invention is not limited to these examples. For instance, the content (and concentration) of the first metallic material in the rotating body 103a may gradually decrease from the rotating body 103a to the rotating turbine blade 102a, while the content (and concentration) of the second metallic material (which constitutes the reinforcing material 368) in the rotating turbine blade 102a may gradually increase. Alternatively, the rotating body 103a may be formed from the first metallic material, and the content (and concentration) of the first metallic material may gradually decrease from the base to the tip of the rotating turbine blade 102a.

[0115] These structures can also be described as structures in which the composition of a metallic material gradually changes (also called material structure or molecular structure).

[0116] The distribution arrangement of metal materials, as shown in the example in Figure 12, can be carried out in the same manner as in the examples in Figures 11(a) and (b). Furthermore, a similar structure can be adopted between the rotating body 103a and the other rotating turbine blades 102b, 102c, etc. In addition, for example, the rotating body 103a can be formed by distributing the first and second metal materials, or the first and second metal materials can be distributed between the rotating body 103a and the lower cylindrical part 103b of the rotating body.

[0117] <Inventions that can be extracted from each embodiment> From the embodiments described above, the following inventions can be extracted. (1) Having a rotor blade (rotor blade 114, etc.) arranged on the rotor shaft (rotor shaft 113, etc.) and rotating together with the rotor shaft, A vacuum pump (turbomolecular pump 100, etc.) that exhausts gas (exhaust gas, process gas, etc.) by exhaust elements (rotating turbine blades 102, rotating body 103a, lower cylindrical part 103b, etc.) provided on the rotor blades due to the rotation of the rotor shaft, The rotor blade is made of multiple metal materials (first metal material, second metal material, etc.), and the constituent parts are manufactured using a fusion additive manufacturing method (3D printer 280, etc.). A vacuum pump characterized in that a reinforcing material (such as a reinforcing material 118), which is a second metal material with higher strength than the first metal material that constitutes the main shape of the rotor blade, is arranged in an integrated configuration. (2) The vacuum pump according to (1) above, characterized in that the reinforcing material is arranged in an internal structure. (3) The vacuum pump according to (1) or (2) above, characterized in that the reinforcing material is arranged such that the second metal material is continuous in the circumferential direction of the rotor blade. (4) The vacuum pump according to (1) or (2) above, characterized in that the reinforcing material is arranged such that the second metal material is continuous in the radial direction of the rotor blade. (5) The vacuum pump according to (1) or (2) above, characterized in that the reinforcing material is arranged such that the second metal material is continuous in the rotor axis direction of the rotor blade. (6) The vacuum pump according to claim 1 or 2, characterized in that the reinforcing material is distributed such that the content of the second metal material changes relative to the first metal material as you move from the inner circumference to the outer circumference of the rotor blade. (7) It consists of multiple metal materials (first metal material, second metal material, etc.), and at least a portion of the constituent parts is manufactured by a fusion additive manufacturing method (3D printer 280, etc.), A vacuum pump component (such as a rotor blade 114) is characterized in that a reinforcing material (such as a reinforcing material 118) which is a metal material (such as a second metal material) with higher strength than the metal material (such as a first metal material) that constitutes the main shape is arranged in an integrated structure.

[0118] <Other> It should be noted that the present invention is not limited to the embodiments described above, and various modifications and combinations of the embodiments are possible without departing from the spirit of the invention.

[0119] For example, it is possible to form a part (e.g., the rotating turbine blades 102 and the rotating body 103a) using a fusion additive manufacturing method (such as a 3D printer) and form other parts (e.g., the lower cylindrical part 103b of the rotating body) by machining. [Explanation of Symbols]

[0120] 100: Turbomolecular pump 102 (102a, 102b, 102c...): Rotary turbine blades 103: Solid of revolution 103a: Rotating body 103b: Lower cylindrical part of the rotating body 113: Rotor shaft 114: Rotary blade 116: Exhaust element 118: Reinforcement material 218, 220: Lower layer 219, 221: Upper layer 222: layer 280: 3D printer 284A: First filament 284B: Second filament 286A: First head section 286B: Second head section

Claims

1. It has rotor blades positioned on the rotor shaft and rotating together with the rotor shaft, A vacuum pump that exhausts gas by exhausting an exhaust element provided on the rotor blade due to the rotation of the rotor shaft, The rotor blade is made of multiple metal materials, and its constituent parts are manufactured by a fusion additive manufacturing method. A reinforcing material, which is a second metal material with higher strength than the first metal material that constitutes the main shape of the rotor blade, is arranged in an integrated configuration. The rotor blade comprises a cylindrical rotating body and a rotating turbine blade formed on the outer circumference of the rotating body, The vacuum pump is characterized in that the reinforcing material is arranged on the rotating body.

2. The vacuum pump according to claim 1, characterized in that the reinforcing material is arranged in an internal structure.

3. The vacuum pump according to claim 1 or 2, characterized in that the reinforcing material is arranged such that the second metal material is continuous in the circumferential direction of the rotating body.

4. The vacuum pump according to claim 1 or 2, characterized in that the reinforcing material is arranged such that the second metal material is continuous in the radial direction of the rotating body.

5. The vacuum pump according to claim 1 or 2, characterized in that the reinforcing material is arranged such that the second metal material is continuous with the rotor axis direction of the rotating body.

6. The vacuum pump according to claim 1 or 2, characterized in that the reinforcing members are arranged in a plurality in a concentric manner on the rotating body.

7. Constituting the rotor blade of a vacuum pump, A vacuum pump component comprising a cylindrical rotating body and rotating turbine blades formed on the outer circumference of the rotating body, It consists of multiple metal materials, and at least a portion of the constituent parts are manufactured by fused deposition modeling. At least the rotating body has a reinforcing material, which is a second metal material with higher strength than the first metal material that constitutes the main shape, arranged in an integrated structure. The vacuum pump component is characterized in that the reinforcing material is arranged on the rotating body.

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