Vacuum pump, and vacuum pump component

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 vacuum pumps, such as turbomolecular pumps, and vacuum pump components. [Background technology]

[0002] Turbomolecular pumps are commonly known as a type of vacuum pump. Turbomolecular pumps are used, for example, for exhausting gases in manufacturing equipment for semiconductors, flat panels, etc. Turbomolecular pumps use a motor inside the pump body to rotate rotors, which ejects gas molecules from the gas (process gas) drawn into the pump body.

[0003] Furthermore, Patent Document 1, which is listed below, discloses that the rotor disc (66) or the stator disc (68) can be manufactured by fused deposition modeling, 3D printing, or the like, and can be composed of two or more component layers. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-205391 Summary of the Invention [Problem to be solved by the invention]

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

[0006] Furthermore, in Patent Document 1, paragraph 0020 states, "The member may be formed from various powder materials. These may be combined, for example, via a buffer layer," and paragraph 0021 states, "Preferably, the member is composed of at least two, particularly laminated, member layers. These layers are then manufactured individually and arranged with each other in the above-mentioned arrangement, and are joined with each other, particularly by lamination."

[0007] However, Patent Document 1 only discloses joining or laminating individually produced component layers, and there is little freedom in selecting the portion where mechanical strength can be improved, selecting the shape of the portion, etc. Therefore, even if the manufacturing method disclosed in Patent Document 1 is adopted, there is a possibility that the mechanical properties of the portion that needs reinforcement will be insufficient.

[0008] SUMMARY OF THE INVENTION It is an object of the present invention to provide a vacuum pump and vacuum pump components having improved mechanical properties. [Means for solving the problem]

[0009] (1) In order to achieve the above object, the vacuum pump according to the present invention comprises: a rotor blade disposed on a rotor shaft and rotating together with the rotor shaft; A vacuum pump that exhausts gas by an exhaust element provided on the rotor blades as the rotor shaft rotates, The rotor blade is made of a plurality of metal materials, and the constituent parts are manufactured by fused deposition modeling; The rotor blade is characterized in that a reinforcing material made of a second metal material having a higher strength than the first metal material that constitutes the main shape of the rotor blade is arranged in an integrally arranged structure. (2) In order to achieve the above object, the vacuum pump component according to the present invention comprises: The part is made of a plurality of metal materials, and at least a part of the part is made by fused deposition modeling; It is characterized by the fact that a reinforcing material, which is a second metal material that is stronger than the first metal material that constitutes the main shape, is arranged in an integrally arranged structure. [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 drawings]

[0011] [Figure 1] 1 is an explanatory diagram schematically showing the configuration of a turbomolecular pump according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a circuit diagram of an amplifier circuit. [Figure 3] 10 is a time chart showing control when a current command value is larger than a detection value. [Figure 4] 10 is a time chart showing control when a current command value is smaller than a detection value. [Figure 5] FIG. 2 is an explanatory diagram showing a reinforced portion of a rotor blade in a hatched manner. [Figure 6]FIG. 2(a) is a plan view schematically showing the shape and arrangement of a reinforcing material according to the first embodiment, and FIG. 2(b) is a vertical cross-sectional side view showing an enlarged portion taken along line AA in FIG. [Figure 7] FIG. 1 is an explanatory diagram schematically illustrating a 3D printer. [Figure 8] 1A is an explanatory diagram showing a schematic diagram of a formation procedure for each layer, FIG. 1B is an explanatory diagram showing another formation procedure for each layer, and FIG. 1C is an explanatory diagram showing yet another formation procedure for each layer. [Figure 9] 10(a) to 10(c) are longitudinal sectional side views schematically showing the shapes and arrangements of reinforcing materials according to second to fourth embodiments. [Figure 10] 10(a) is a plan view schematically showing the shape and arrangement of a reinforcing material according to a fifth embodiment, and FIG. 10(b) is a vertical cross-sectional side view showing an enlarged portion taken along line BB in FIG. [Figure 11] 10(a) is a plan view schematically showing the shape and arrangement of a reinforcing material according to a sixth embodiment, and FIG. 10(b) is a vertical cross-sectional side view showing an enlarged portion taken along line CC in FIG. [Figure 12] FIG. 13 is a vertical cross-sectional side view schematically showing a reinforcing material according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Basic Configuration of the Turbomolecular Pump 100 According to the First Embodiment> 1 shows a vertical cross-sectional view of a turbomolecular pump 100 as a vacuum pump according to a first embodiment of the present invention. This turbomolecular pump 100 is adapted to be connected to a vacuum chamber (not shown) of a target device such as a semiconductor manufacturing device.

[0013] 1, a turbomolecular pump 100 has an intake port 101 formed at the upper end of a cylindrical outer cylinder 127. Inside the outer cylinder 127, a rotor 103 is provided, on the periphery of which are formed a plurality of rotating turbine impellers 102 (102a, 102b, 102c, etc.), which are turbine blades for sucking in and exhausting gas, arranged radially and in multiple stages.

[0014] In the following, the rotating turbine blades (turbine blade portions) of multiple stages may be collectively referred to as "rotary turbine blades 102." Furthermore, when there is no need to particularly distinguish between the rotating turbine blades (turbine blade portions) of each stage, they may be collectively referred to as "rotary turbine blades 102." Furthermore, as necessary, the rotating turbine blades (turbine blade portions) may be distinguished by stage and referred to as "rotary turbine blade 102a," "rotary turbine blade 102b," "rotary turbine blade 102c," etc. Each stage is configured to include multiple blades (blade portions), similar to a typical turbomolecular pump. The same applies to the stationary turbine blades 123 (123a, 123b, 123c, etc.) and stationary 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 supported in the air and its position is controlled by, for example, a five-axis controlled magnetic bearing. In this embodiment, the rotating body 103 has the rotor shaft 113, and the rotor shaft 113 and rotor blades 114 are combined to form the rotating body 103. The structure of the rotor blades 114 will be described in detail later.

[0016] The upper radial electromagnets 104 are arranged in pairs on the X-axis and the Y-axis. Four upper radial sensors 107 are provided adjacent to the upper radial electromagnets 104 and corresponding to each upper radial electromagnet 104. The upper radial sensors 107 are, for example, inductance sensors or eddy current sensors having conductive windings, and detect the position of the rotor shaft 113 based on changes in the inductance of the conductive windings, which change according to the position of the rotor shaft 113. The upper radial sensors 107 are configured to detect the radial displacement of the rotor shaft 113, i.e., the rotating body 103 fixed thereto, and send the detected displacement 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 a position signal detected by the upper radial sensor 107, and an 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 magnetic permeability material (iron, stainless steel, etc.) and is attracted by the magnetic force of the upper radial electromagnets 104. Such adjustment is performed independently in the X-axis direction and the Y-axis direction. The lower radial electromagnets 105 and the lower radial sensors 108 are arranged in the same manner as the upper radial electromagnets 104 and the upper radial sensors 107, and adjust the radial position of the lower side of the rotor shaft 113 in the same manner as the radial position of the upper side.

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

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

[0021] In this way, the control device 200 appropriately adjusts the magnetic forces that the axial electromagnets 106A and 106B exert on the metal disk 111, magnetically levitating the rotor shaft 113 in the axial direction and holding it in space without contact. The amplifier circuit 150 that controls the excitation of the upper radial electromagnet 104, the lower radial electromagnet 105, and the axial electromagnets 106A and 106B will be described later.

[0022] Meanwhile, motor 121 has a plurality of magnetic poles arranged circumferentially so as to surround rotor shaft 113. Each magnetic pole is controlled by control device 200 so as to rotate rotor shaft 113 via electromagnetic force acting between the magnetic pole and rotor shaft 113. Motor 121 also incorporates a rotational speed sensor (not shown), such as a Hall element, resolver, or encoder, and the rotational speed of rotor shaft 113 is detected by the detection signal of this rotational speed sensor.

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

[0024] A plurality of fixed turbine blades 123 (123a, 123b, 123c...) are arranged at small gaps (predetermined intervals) from the rotating turbine blades 102 (102a, 102b, 102c...). Each of the rotating turbine blades 102 (102a, 102b, 102c...) is inclined at a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113 in order to transport exhaust gas molecules downward through collisions.

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

[0026] The fixed vane spacer 125 is a ring-shaped member made of a metal such as aluminum, iron, stainless steel, or copper, or an alloy containing any of these metals. An outer cylinder 127 is fixed to the outer periphery of the fixed vane spacer 125 with a small gap between them. A base portion 129 is disposed 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 disposed between the lower part of the fixed vane spacer 125 and the base portion 129. The threaded spacer 131 is a cylindrical member made of a metal such as aluminum, copper, stainless steel, iron, or an alloy containing any of these metals, and has a plurality of spiral thread grooves 131a engraved on its inner circumferential surface. The spiral direction of the thread grooves 131a corresponds to the direction in which exhaust gas molecules are transported toward the exhaust port 133 when they move in the rotation direction of the rotor 103. A rotor lower cylindrical portion 103b hangs down from the lower part of a rotor main body 103a on which the rotating turbine blades 102 (102a, 102b, 102c, etc.) of the rotor 103 are formed. The outer peripheral surface of the rotor lower cylindrical portion 103b is cylindrical and projects toward the inner peripheral surface of the threaded spacer 131, with a predetermined gap separating them. Exhaust gas transferred to the thread grooves 131a by the rotating turbine impellers 102 and the fixed turbine impellers 123 is guided along the thread grooves 131a and sent to the base portion 129. In this manner, the threaded spacer 131 and the opposing rotor lower cylindrical portion 103b constitute a Holweck-type exhaust mechanism 204. The Holweck-type exhaust mechanism 204 imparts directionality to the exhaust gas by the rotation of the rotor lower cylindrical portion 103b relative to the threaded spacer 131, thereby improving the exhaust characteristics of the turbomolecular pump 100.

[0028] The base portion 129 is a disk-shaped member that forms the base of the turbomolecular pump 100, and is generally made of metal such as iron, aluminum, stainless steel, etc. 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 impeller 102 is rotated together with the rotor shaft 113 by the motor 121, exhaust gas is drawn from the chamber through the intake port 101 by the action of the rotating turbine impeller 102 and the fixed turbine impeller 123. The exhaust gas drawn in through the intake port 101 passes between the rotating turbine impeller 102 and the fixed turbine impeller 123 and is transferred to the base portion 129. At this time, the temperature of the rotating turbine impeller 102 rises due to frictional heat generated when the exhaust gas comes into contact with the rotating turbine impeller 102 and conduction of heat generated by the motor 121, but this heat is transferred to the stationary turbine impeller 123 side by radiation or conduction by gas molecules of the exhaust gas.

[0030] The fixed blade spacers 125 are joined together at their outer peripheries and transmit to the outside heat received by the fixed turbine blades 123 from the rotating turbine blades 102 and frictional heat generated when exhaust gas comes into contact with the fixed turbine blades 123.

[0031] In the above description, the threaded spacer 131 is disposed on the outer periphery of the rotor lower cylindrical portion 103b of the rotor 103, and the thread groove 131a is formed on the inner circumferential surface of the threaded spacer 131. However, conversely, there are also cases where a thread groove is formed on the outer circumferential surface of the rotor lower cylindrical portion 103b, and a spacer having a cylindrical inner circumferential surface is disposed around it.

[0032] Depending on the application of the turbomolecular pump 100, the electrical equipment section may be surrounded by a stator column 122 to prevent the gas sucked in from the intake port 101 from entering the electrical equipment section, which is composed of the upper radial electromagnet 104, the upper radial sensor 107, the motor 121, the lower radial electromagnet 105, the lower radial sensor 108, the axial electromagnets 106A and 106B, the axial sensor 109, etc., and the interior of this stator column 122 may be kept at a predetermined pressure by purge gas.

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

[0034] Here, the turbomolecular pump 100 requires control based on specific parameters (e.g., various characteristics corresponding to the model) that have been individually adjusted and identified for the model. To store these control parameters, the turbomolecular pump 100 is provided with an electronic circuit section 141 within its body. The electronic circuit section 141 is composed of a semiconductor memory such as an EEPROM, electronic components such as semiconductor elements for accessing the memory, and a substrate 143 for mounting these components. The electronic circuit section 141 is housed below a rotational speed sensor (not shown) near the center of a base section 129 that constitutes the lower part of the turbomolecular pump 100, and is closed by an airtight bottom lid 145.

[0035] In the semiconductor manufacturing process, some process gases introduced into a chamber have the property of solidifying when their pressure exceeds a predetermined value or their temperature falls below a predetermined value. Inside the turbomolecular pump 100, the pressure of the exhaust gas is lowest at the inlet port 101 and highest at the outlet port 133. If the pressure of the process gas exceeds a predetermined value or the temperature falls below a predetermined value while the process gas is being transferred from the inlet port 101 to the outlet port 133, the process gas solidifies and adheres to and accumulates inside the turbomolecular pump 100.

[0036] For example, when SiCl4 is used as the process gas in an Al etching system, the low vacuum (760 [torr] to 10 -2The vapor pressure curve shows that at temperatures of 100[torr]) and low temperatures (approximately 20[°C]), solid products (e.g., AlCl3) precipitate and adhere to and accumulate inside the turbomolecular pump 100. When process gas deposits accumulate inside the turbomolecular pump 100, these deposits narrow the pump flow path, causing a decrease in the performance of the turbomolecular pump 100. The aforementioned products are prone to solidification and adhesion in high-pressure areas near the exhaust port 133 and near the threaded spacer 131.

[0037] Therefore, in order to solve this problem, conventionally, a heater (not shown) or a circular water-cooled pipe 149 is wound around the outer periphery of the base portion 129, etc., and a temperature sensor (e.g., a thermistor) (not shown) is embedded in the base portion 129, and heating by the heater and cooling by the water-cooled pipe 149 are controlled based on a signal from the temperature sensor to maintain the temperature of the base portion 129 at a constant high temperature (set temperature) (hereinafter referred to as TMS; Temperature Management System). 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 the water-cooled pipe 149 embedded in the bottom cover 145.

[0038] Next, regarding the turbomolecular pump 100 configured as described above, we will explain the amplifier circuit 150 that controls excitation of the upper radial electromagnets 104, the lower radial electromagnets 105, and the axial electromagnets 106A and 106B. A circuit diagram of this amplifier circuit is shown in Figure 2.

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

[0040] At this time, the transistor 161 has a diode cathode terminal 161a connected to the positive electrode 171a and an anode terminal 161b connected to one end of the electromagnet winding 151. The transistor 162 has a diode cathode terminal 162a connected to the current detection circuit 181 and an anode terminal 162b connected to the negative electrode 171b.

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

[0042] The amplifier circuit 150 configured as above corresponds to one electromagnet. Therefore, if the magnetic bearing is controlled in five axes and there are a total of ten electromagnets 104, 105, 106A, and 106B, a similar amplifier circuit 150 is configured for each electromagnet, and the ten 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 section (hereinafter referred to as a DSP section) not shown in the figure of the control device 200, and this amplifier control circuit 191 is configured to switch the transistors 161 and 162 on / off.

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

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

[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 electromagnet current iL) increases, and when both are turned off, the electromagnet current iL decreases.

[0047] Furthermore, when one of the transistors 161 and 162 is turned on and the other is turned off, a so-called flywheel current is maintained. By passing a flywheel current through the amplifier circuit 150 in this manner, hysteresis loss in the amplifier circuit 150 can be reduced, and the power consumption of the entire circuit can be kept low. Furthermore, by controlling the transistors 161 and 162 in this manner, high-frequency noise such as harmonics generated in the turbomolecular pump 100 can be reduced. Furthermore, 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] That is, when the detected current value is smaller than the current command value, both transistors 161 and 162 are turned on for a time period corresponding to pulse width time Tp1 only once in a control cycle Ts (for example, 100 μs), as shown in Fig. 3. Therefore, during this period, the electromagnet current iL increases toward a current value iLmax (not shown) that can flow from the positive electrode 171a to the negative electrode 171b via the 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 for a time period corresponding to pulse width time Tp2 only once during the control cycle Ts, as shown in Fig. 4. Therefore, the electromagnet current iL during this period decreases toward a current value iLmin (not shown) that can be regenerated from the negative pole 171b to the positive pole 171a via diodes 165 and 166.

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

[0051] 1 (the side of the intake port 101) serves as an intake section connected to the target device, and the lower side (the side on which the exhaust port 15 constituting the exhaust port 133 is provided on the base portion 129 so as to protrude to the right in the figure) serves as an exhaust section connected to an auxiliary pump (back pump) or the like (not shown). The turbomolecular pump 100 can be used in an inverted, horizontal, or inclined position in addition to the vertical position shown in FIG.

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

[0053] The internal configuration of the main body casing of the turbomolecular pump 100 (here, a combination of the outer cylinder 127 and the base portion 129) can be divided into a rotation mechanism portion 136 that rotates the rotor shaft 113 and the like by the motor 121, and an exhaust mechanism portion 137 that is rotationally driven by the rotation mechanism portion 136. The exhaust mechanism portion 137 can also be divided into a turbomolecular pump mechanism portion (turbomolecular pump portion) 138 that is composed of the rotating turbine impeller 102, the fixed turbine impeller 123, and the like, and a thread groove pump mechanism portion (Hollweck type exhaust mechanism portion 204) that is composed of the rotor lower cylindrical portion 103b, the threaded spacer 131, and the like.

[0054] The aforementioned purge gas (protective gas) is used to protect the bearing parts and the rotating turbine blades 102, etc., to prevent corrosion caused by the exhaust gas (process gas), and to cool the rotating turbine blades 102. This purge gas can be supplied by a general method.

[0055] For example, the aforementioned purge gas port 132 extending linearly in the radial direction is provided at a predetermined position (such as a position 90 degrees or 120 degrees away from the exhaust port 133) of the base portion 129. Then, purge gas is 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 rate regulator (valve device).

[0056] The aforementioned protective bearings 120 are also called "touchdown (T / D) bearings" or "backup bearings." These protective bearings 120 prevent the position or attitude of the rotor shaft 113 from changing significantly, even in the unlikely event of a problem with the electrical system or atmospheric inrush, thereby preventing damage to the rotating turbine blades 102 and their surrounding areas.

[0057] In FIG. 1 showing the structure of the turbo molecular pump 100 and the rotor 103, hatching showing cross sections of components is omitted to avoid cluttering the drawing.

[0058] <Configuration of Rotor 114> As described above, the rotor blades 114 are combined with the rotor shaft 113 and rotate together with the rotor shaft 113. The rotor blades 114 have a rotor main body 103a and a rotor lower cylindrical portion 103b, and a large number of rotary turbine blades 102 (102a, 102b, 102c, etc.) are integrally formed with the rotor main body 103a. Then, as the rotor shaft 113 rotates, gas (exhaust gas, process gas) is exhausted by the exhaust element 116 provided on the rotor blades 114.

[0059] The exhaust element 116 provided on the rotor 114 includes, for example, portions and components (parts) of the rotor 114 that come into contact with gas (exhaust gas, process gas) and are directly involved in exhaust. Specifically, the exhaust element 116 includes, for example, the rotating turbine blades 102 (102a, 102b, 102c, etc.), the rotor main body 103a, and the rotor lower cylindrical portion 103b.

[0060] The rotor 114 is made of a plurality of metal materials, and the components (parts that make up the rotor 114) are manufactured by fused deposition modeling. Furthermore, the rotor 114 has a reinforcing member 118 (described later in FIGS. 6(a) and 6(b)), which is a metal material stronger than the metal material that makes up the main shape of the rotor 114, arranged in an integrally arranged structure. Hereinafter, the metal material that makes up the main shape of the rotor 114 may be referred to as the "first metal material" or "main material," and the metal material of the reinforcing member 118 may be referred to as the "second metal material" or "high-strength material."

[0061] In this embodiment, the reinforcing material 118 is disposed in a region extending from the rotor main body 103a to the rotor lower cylindrical portion 103b of the rotor 114. This is shown schematically in Figure 5. In Figure 5, only the region (disposition target region) 119 in which the reinforcing material 118 is to be disposed in this embodiment is hatched.

[0062] It should be noted that the placement target area 119 is not limited to the range shown in Fig. 5. The placement target area 119 may be, for example, narrower than the range shown in Fig. 5, or wider than the range shown in Fig. 5. The placement target area 119 may reach the inside of the rotating turbine blades 102 (102a, 102b, 102c, etc.), or may be limited to the inside of the rotating turbine blades 102 (102a, 102b, 102c, etc.).

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

[0064] The high-strength material (second metal material) that becomes the reinforcing material 118 is a metal material that has greater strength (such as tensile strength) than the main material (first metal material) used in the "main shape" portion. In addition, the high-strength material may be a metal material that has a smaller linear expansion coefficient or a smaller 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 employed. 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, it is also possible to use an aluminum alloy or magnesium alloy as the main material and a stainless alloy with a high strength-to-weight ratio, such as SUS630, as the high-strength material. Also, by focusing on the specific gravity of the materials, it is possible to use, for example, a metal material with a relatively low specific gravity (and density) for the rotary turbine impeller 102, and a metal material with a relatively high specific gravity for the rotor main body 103a (and / or rotor lower cylindrical portion 103b). By doing so, a weight distribution is obtained for the rotor 114 in which the specific gravity is light on the radially outer side and heavy on the inner side. Furthermore, a structure is obtained in which the tensile strength of the base portion (here, the rotor main body 103a) that supports the rotary turbine impeller 102 is stronger than that of the rotary turbine impeller 102. Furthermore, compared to when a metal material with a high specific gravity is used on the radially outer side and a heavy metal material on the inner side, the force acting in the centrifugal direction and downward direction is smaller, making it easier to maintain the bond between the materials. Furthermore, the present invention is not limited to this, and it is also possible to use a metal material with a higher specific gravity on the radially outer side and a metal material with a heavier specific gravity on the radially inner side. In this way, the relationship between specific gravities can be changed depending on which mechanical properties are emphasized.

[0067] FIG. 6(a) is a schematic diagram showing a state in which the rotor main body 103a (or the rotor lower cylindrical portion 103b) of the rotor 114 is cut perpendicular to the axial direction (in the radial direction). In the example of FIG. 6(a), the reinforcing members 118 are arranged in a ring shape along the cylindrical shape of the rotor main body 103a (or the rotor lower cylindrical portion 103b). Furthermore, in the example of FIG. 6(a), the reinforcing members 118 are arranged in three concentric layers in the radial direction of the rotor main body 103a (and / or the rotor lower cylindrical portion 103b). In FIG. 6(a), the reinforcing members 118 are arranged in the order of a first reinforcing member 118A, a second reinforcing member 118B, and a third reinforcing member 118C from the inside out. 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 cross section taken along line AA in Figure 6(a). In the example of Figure 6(b), the first reinforcing material 118A to the third reinforcing material 118C are arranged parallel to one another and extend linearly along the axial direction of the rotor 114. Here, in Figures 6(a) and 6(b), for emphasis, only the reinforcing material 118 (the first reinforcing material 118A to the third reinforcing material 118C) are hatched.

[0069] As shown in FIGS. 6(a) and 6(b), the reinforcing material 118 is arranged in an embedded structure. The "embedded structure" refers to a structure in which reinforcing material 118 (here, first reinforcing material 118A to third reinforcing material 118C) made of a high-strength material (second metal material) is embedded inside the "main shape" portion of the main material (first metal material). In the example of FIGS. 6(a) and 6(b), the reinforcing material 118 is arranged in an embedded structure within the main material (first metal material) via an "integral arrangement structure" with the "main shape" portion. The reinforcing material 118 is in close contact with and bonded to the "main shape" portion so as to leave no gaps.

[0070] As described above, the plurality of metal materials includes metal materials with different strengths. The plurality of metal materials also includes metal materials with different linear expansion coefficients. Furthermore, the plurality of metal materials also includes metal materials with different specific gravities. An example of a combination of metal materials that satisfies this relationship is aluminum and stainless steel. As described above, the reinforcing member 118 is arranged so as to be continuous in the circumferential direction (annularly) in the rotor main body 103a (in the rotor blades). It can also be said that the reinforcing member 118 is arranged so as to be continuous in the radial direction with a predetermined width in the rotor main body 103a (in the rotor blades 114). It can also be said that the reinforcing member 118 is arranged so as to be continuous in the rotor axial direction (axial direction of the rotor shaft 113) in the rotor main body 103a (in the rotor blades 114). In this way, since the reinforcing material 118 is continuously arranged in the circumferential and radial directions, when a circumferential or radial load is applied to the rotor 114 due to thermal expansion, centrifugal force, or the like, the effect of the reinforcing material 118 can be fully exerted, and deformation of the rotor 114 can be effectively suppressed. Furthermore, since the reinforcing material 118 is continuously arranged in the axial direction, the effect of the reinforcing material 118 can be fully exerted, and deformation of the rotor 114 can be effectively suppressed, just as when the reinforcing material 118 is continuously arranged in the circumferential or radial direction.

[0071] Such "integrally arranged structures" (and "built-in structures") are formed by fused deposition modeling. Examples of fused deposition modeling include 3D printers, which 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 machines, additive manufacturing machines, or AM (Additive Manufacturing) machines.

[0072] <Example of 3D Printer 280> Any 3D printer can be used in this embodiment as long as it can form an "integrated structure" (and an "internal structure") using multiple metal materials. Examples of 3D printer methods that can be used include the FDM (Fused Deposition Modeling, registered trademark) method (also known as the FFF (Fused Filament Fabrication) method).

[0073] FIG. 7 schematically illustrates the basic configuration (one example) of a 3D printer (three-dimensional modeling apparatus) 280 using the FDM method. The 3D printer 280 includes a first filament supply unit 282A and a second filament supply unit 282B (not shown). In FIG. 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 delivered from the first filament supply unit 282A. A second filament 284B containing a binder is delivered 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, and stacks each layer to form a three-dimensional object. The bonding of the modeling material is performed by melting the first filament 284A, which contains a binder, using a heat source.

[0075] The 3D printer 280 is equipped with a second head unit 286B, and switches the head unit in use from the first head unit 286A to the second head unit 286B as necessary. Furthermore, the 3D printer 280 may also switch the head unit in use from the second head unit 286B to the first head unit 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 stacks each layer to form a three-dimensional object. The bonding of the modeling material is performed by melting the second filament 284B, which contains a binder, using a heat source.

[0077] The 3D printer 280 is provided with a table unit 278 that can move up and down in the Z-axis direction, and modeling is performed on the table unit 278. The table unit 278 descends as modeling progresses, making it possible to maintain or adjust the distance between the first head unit 286A and the second head unit 286B.

[0078] A first filament 284A and a second filament 284B made of different types of metal materials are individually supplied to the first head unit 286A and the second head unit 286B. Then, the first filament 284A (or the second filament 284B) to be used for modeling is guided to the modeling position, and 3D printing is performed using a filament (the first filament 284A or the second filament 284B) made of a metal material appropriate for the portion of the target to be modeled (here, the rotor 114). For example, the metal material of the first filament 284A can be aluminum, and the metal material of the second filament 284B can be stainless steel.

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

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

[0081] Depending on the part to be formed, the position of the end (end in the scanning direction) of portion 218A (or portion 218B) in the lower layer 218 and the position of the end (end in the scanning direction) of portion 219A (or portion 219B) in the upper layer 219 may be different (may be shifted in the scanning direction).

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

[0083] Furthermore, the scanning direction of the first head unit 286A (and the second head unit 286B) may be different 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 scan 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 scan in the direction indicated by arrow A.

[0084] Also, depending on the portion of the rotor 114, it is possible to perform a shape as schematically shown in Fig. 8(b). In the example of Fig. 8(b), for the lower layer 220, the first head unit 286A (and the second head unit 286B) is scanned in the direction indicated by arrow A, and a portion 220A that will become the rotor main body 103a (a portion that constitutes the "main shape") is formed. Next, for the upper layer 221, the first head unit 286A (and the second head unit 286B) is scanned in the same direction indicated by arrow A, and a portion 221A that will become the rotor main body 103a and a portion 221B that will become the reinforcing material 118 are formed in that order.

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

[0086] Also, depending on the portion of the rotor 114, it is possible to perform shaping as shown schematically in Fig. 8(c). In the example of Fig. 8(c), a portion 222A1 that will become the rotor main body 103a (a portion that constitutes the "main shape") is formed as part of one layer 222, and then a portion 222B1 that will become the reinforcing material 118 is formed as part of the same layer 222. Next, a portion 222A2 that will become the rotor main body 103a is formed as part of the same layer 222, and then a portion 222B2 that will become the reinforcing material 118 is formed as part of the same layer 222.

[0087] In the 3D printer 280, by appropriately combining layers such as those shown as examples in Figures 8(a) to (c), it is possible to form a gapless ``integral arrangement structure'' (and ``built-in structure'') according to this embodiment.

[0088] The 3D printer 280 may have the following functions. For example, the 3D printer 280 may include a drive mechanism that guides the first head unit 286A and the second head unit 286B with high positioning accuracy. The drive mechanism that guides the first head unit 286A and the second head unit 286B may include, for example, a stepping motor with an encoder or a linear guide, although not shown. This allows the subsequent modeling to be performed in a manner that is contiguous with the previously modeled portion with high accuracy when switching between the first filament 284A and the second filament 284B or when replacing the first filament 284A (or the second filament 284B).

[0089] Furthermore, the 3D printer 280 may be equipped with a table heater (reference numeral omitted) that can heat the table 278. In this case, the table 278 can be heated to a predetermined temperature (for example, approximately 100°C or higher). By appropriately heating the table 278, it is possible to reduce the temperature difference between the material (model) and the table 278, and prevent the model from shrinking excessively due to a drop in temperature.

[0090] The table 278 may be made of a material with sufficient thermal conductivity (for example, aluminum). Furthermore, the table 278 may be made of a material with a sheet having a moderately fine unevenness attached to its surface to enhance the fixation of the object. The unevenness of the sheet ensures a large contact area between the object and the table 278, preventing deformation of the object.

[0091] Furthermore, the 3D printer 280 may be equipped with an internal heater (reference numeral omitted) that can heat the interior of the chamber (the space where the modeling is performed) to a predetermined temperature (for example, about 70°C or higher). By heating the interior of the chamber, it is possible to prevent the temperature of the modeled object from dropping and causing excessive shrinkage.

[0092] Regarding the bonding of the modeling materials layered by the 3D printer 280, it is also possible to sinter the model that has been solidified using a binder.

[0093] <Details of the integrated layout structure> The "integrally arranged structure" (and "built-in structure") described above includes a structure in which a portion made of one metal material is disposed within a portion made of another metal material, and a structure in which a portion made of one metal material is integrally bonded to a portion made of the other metal material. The "built-in structure" is a structure in which the reinforcing member 118 is embedded in (or disposed within) a member that forms the main shape (here, the member that forms the outer shape of the rotor main body 103a and the rotor lower cylindrical portion 103b, the first metal material). The "integrally bonded structure" referred to here includes a configuration in which multiple metal materials form a mechanically bonded structure. The "mechanically bonded structure" referred to here means a configuration in which multiple metal materials are bonded together without using mechanical fasteners such as bolts. Furthermore, the "integral arrangement structure" can be arranged on the outer or inner peripheral surface of the main component, and the location is not limited, including on the surface or inside.

[0094] In general, methods for joining metal materials can be broadly divided into mechanical joining, material joining, and chemical joining. Of these, mechanical joining includes bolting, riveting, shrink fitting, cold fitting, and caulking. Material joining includes fusion welding, resistance welding, solid-state welding, diffusion bonding, brazing and soldering, pressure welding, friction welding, sintering, and insert casting. Chemical joining includes adhesive bonding, plating, and vapor deposition.

[0095] The "mechanically bonded structure" in this embodiment is a bonded structure formed by a fused deposition modeling method such as a 3D printer, and is not classified as a bonding method that uses mechanical fasteners such as bolts, rivets, etc. According to 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 "integral arrangement structure" is used in this specification.

[0096] <Comparison of the technology according to this embodiment with the conventional technology> According to the turbomolecular pump 100 of this embodiment as described above, the reinforcing material 118, which is a metal material (second metal material) stronger than the metal material (first metal material) that constitutes the main shape of the rotor 114, is arranged in an "integrally arranged structure", and therefore has the following advantages (merits) compared to the conventional technology (described later).

[0097] As prior art, in addition to the above-mentioned Patent Document 1, for example, Japanese Patent Application Laid-Open No. 2005-180265 can be mentioned.

[0098] Japanese Patent Application Laid-Open No. 2005-180265 (paragraphs 0015, 0043, etc.) discloses that "...reinforcing 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] When casting, as in the invention disclosed in JP 2005-180265 A, the parts thermally expand during casting, making it difficult to obtain the desired dimensions (expected dimensions, designed dimensions). Furthermore, when dissimilar metals are cast and then contract, gaps may form at the interface due to differences in thermal expansion coefficients. Furthermore, if the melting points of the components are close, the components to be cast may also melt, so combinations of metals with sufficiently different melting points are limited. Furthermore, because the components are heated to high temperatures during casting, the effects of heat treatment during material production are diminished, potentially reducing the strength of the material.

[0100] In addition, as in the invention disclosed in JP 2005-180265 A, when high-strength fibers are inserted into the rotor to reinforce it, die-casting is used to form the exterior material (the main material in this application) around the fibers. However, if this method is used for the entire rotor, the fiber material must first be processed into the rotor shape, which requires many steps. Furthermore, if the exterior material is not formed with a uniform thickness, the weight distribution may be unbalanced.

[0101] In contrast to the conventional techniques described above, the turbomolecular pump 100 of this embodiment uses a 3D printer to manufacture the rotor 114 integral with the reinforcing material 118, eliminating the need to preliminarily separate and manufacture each part even when combining two or more types of materials (metal materials), and making assembly of parts unnecessary (or easy). Furthermore, the turbomolecular pump 100 of this embodiment also uses an "integral arrangement structure" to provide reinforcement using dissimilar materials (dissimilar metal materials), which also makes assembly unnecessary (or easy). This also makes it possible to easily provide partial reinforcement of the rotor 114.

[0102] Furthermore, according to the turbomolecular pump 100 of this embodiment, the entire rotor 114 is manufactured as a single unit by 3D printing, eliminating various problems associated with conventional techniques, such as bolting, shrink fitting, and casting, when assembling dissimilar materials. Furthermore, by employing an internal structure as one type of "integral arrangement structure," components can be firmly joined and fixed without the need for tedious assembly work. Furthermore, the "integral arrangement structure" and "internal structure" make it possible to change and optimize the strength of the rotor 114 either entirely or partially. Furthermore, such rotors 114 can be manufactured continuously and precisely in one go.

[0103] Furthermore, because the "integrated structure" is formed using the 3D printer 280, gaps can be prevented from occurring between the metal material (first metal material) that forms the main shape of the rotor 114 and the reinforcing material 118, which is a stronger metal material (second metal material), and the two metal materials can be bonded in close contact. This makes it possible to firmly bond parts made of different metal materials. Furthermore, because the shaping is performed using the 3D printer 280, even if a metal material that is relatively difficult to process with a blade (e.g., stainless steel or titanium) is used as the second metal material (or the first metal material), the difficulty of processing is not a factor. Therefore, the rotor 114 can be easily formed regardless of the material selected.

[0104] The 3D printer 280 may be used to form only a portion of the rotor 114 (for example, the rotor main body 103a, the rotor lower cylindrical portion 103b, and the rotary turbine blade 102) and the reinforcing member 118. Furthermore, the reinforcing member 118 may be formed only inside the rotary turbine blade 102, or may straddle both the rotor main body 103a and the inside of the rotary turbine blade 102. When the reinforcing member 118 is formed so as to straddle both the rotor main body 103a and the inside of the rotary turbine blade 102, the bonding strength between the rotor main body 103a and the root portion (base end) of the rotary turbine blade 102 can be improved.

[0105] Here, the cylindrical portions such as the rotor main body 103a and the rotor lower cylindrical portion 103b are deformed by centrifugal force as the rotor 114 rotates, bulging outward. Therefore, by arranging reinforcing members 118 in the circumferential direction as in the example of Figures 6(a) and 6(b), the generated load can be efficiently borne by the reinforcing members 118, and the rotor 114 can be effectively reinforced.

[0106] Furthermore, when the reinforcing material 118 is embedded inside the rotary turbine blade 102, the reinforcing material 118 can be arranged (oriented) in a state of being obliquely oriented or curved, etc., along the curved surface shape or cross-sectional shape of the rotary turbine blade 102. In this way, the rotary turbine blade 102, which has a complex shape and is subjected to loads in complex directions (multiple directions including twisting and lifting directions), can be effectively reinforced in accordance with the shape and the direction of the load.

[0107] The shape and arrangement of the reinforcing members 118 are not limited to the structures shown in the examples of FIGS. 6(a) and 6(b), and various other structures and arrangements can be employed. For example, in the examples of FIGS. 6(a) and 6(b), cylindrical reinforcing members 118A to 118C are arranged in triplicate. In contrast, in the example of FIG. 9(a) (second embodiment), the reinforcing members 318 are formed linearly and extend annularly in the circumferential direction of the rotor main body 103a. Furthermore, the number of reinforcing members 318 is four or more, and the cross-sectional shape of each reinforcing member 318 is a perfect circle. Furthermore, the numerous reinforcing members 318 are arranged in a staggered (diagonal) pattern.

[0108] 9(a), the reinforcing members 328 are formed linearly and extend annularly in the circumferential direction of the rotor main body 103a. Furthermore, the number of reinforcing members 328 is four or more. Each reinforcing member 328 has a rectangular (square) cross-sectional shape, and the numerous reinforcing members 328 are arranged in a matrix.

[0109] 9(c) (fourth embodiment), the reinforcing members 338 are formed linearly and extend annularly in the circumferential direction of the rotor main body 103a, similar to the examples of FIGS. 9(a) and 9(b). Furthermore, the number of reinforcing members 328 is four or more. The cross-sectional shape of each reinforcing member 338 is diamond-shaped, and the arrangement (disposition) of the multiple reinforcing members 338 is staggered (diagonal).

[0110] In the example of Figures 10(a) and (b) (fifth embodiment), multiple (here, eight) annular reinforcing members 348 are arranged approximately parallel and at approximately equal intervals along the axial direction of the rotor 114 inside the cylindrical rotor main body 103a (or rotor lower cylindrical portion 103b).

[0111] In the example (sixth embodiment) of Figures 11(a) and (b), the second metallic material constituting the reinforcing member 358 is distributed and partially mixed in the impeller 114. Specifically, there are portions where the second metallic material constituting the reinforcing member 358 is mixed with the first metallic material, which is the primary material, and the content (and concentration) of the second metallic material decreases as one moves from the inner periphery to the outer periphery of the impeller 114. In contrast, the content (and concentration) of the first metallic material, which is the primary material, increases as one moves from the inner periphery to the outer periphery of the impeller 114. In Figures 11(a) and (b), this is represented by a gradation between light and dark grayscale colors. However, without being limited to this, for example, the content (and concentration) of the second metal material may be changed so as to increase as one moves from the inner periphery to the outer periphery of the rotor 114, and the content (and concentration) of the first metal material may be changed so as to decrease as one moves from the inner periphery to the outer periphery of the rotor 114.

[0112] These structures can be said to be structures (also called material structures, molecular structures, etc.) in which the components (composition) of the metal material change gradually.

[0113] As a method for distributing and arranging metal materials as in the examples of Figures 11(a) and (b), for example, a method can be used in which the first metal material (or the second metal material) is diffused into the second metal material (or the first metal material) to bond both materials.

[0114] Next, in the example of Fig. 12 (seventh embodiment), metallic materials are distributed between the rotor body 103a and the rotary turbine blade 102a. In the example of Fig. 12, the content (and concentration) of the first metallic material in the rotor body 103a gradually increases from the rotor body 103a to the rotary turbine blade 102a, while the content (and concentration) of the second metallic material (constituting the reinforcing material 368) in the rotary turbine blade 102a gradually decreases. In the example of Fig. 12, this is represented by a gradation of grayscale from light to dark. 12, the first metallic material is also used to form the rotor main body 103a, and the concentration of the second metallic material gradually decreases from the inner periphery to the outer periphery of the rotor main body 103a and further to the rotary turbine blade 102a. However, the rotor main body 103a may be formed from the second metallic material, and the concentration of the second metallic material may gradually decrease from the base end to the tip end of the rotary turbine blade 102a. However, without being limited thereto, for example, the content (and concentration) of the first metallic material in the rotor body 103a may gradually decrease from the rotor body 103a to the rotor turbine blade 102a, and the content (and concentration) of the second metallic material (constituting the reinforcing material 368) in the rotor turbine blade 102a may gradually increase. Alternatively, the rotor 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 end to the tip end of the rotor turbine blade 102a.

[0115] These structures can also be said to be structures (also called material structures, molecular structures, etc.) in which the components (compositions) of the metal material change gradually.

[0116] The distribution of metal materials as shown in the example of Figure 12 can be achieved in the same way as the examples of Figures 11(a) and 11(b). A similar structure can also be adopted between the rotor main body 103a and the other rotary turbine blades 102b, 102c, etc. Furthermore, for example, it is also possible to form the rotor main body 103a by distributing a first metal material and a second metal material, or to distribute a first metal material and a second metal material between the rotor main body 103a and the rotor lower cylindrical portion 103b.

[0117] <Inventions that can be extracted from each embodiment> The following inventions can be extracted from the above-described embodiments. (1) A rotor shaft (such as rotor shaft 113) is provided with a rotor blade (such as rotor blade 114) that rotates together with the rotor shaft; A vacuum pump (such as a turbomolecular pump 100) that exhausts gas (such as an exhaust gas or a process gas) by means of exhaust elements (such as a rotating turbine blade 102, a rotor body main body 103 a, and a rotor lower cylindrical portion 103 b) provided on the rotor shaft as the rotor shaft rotates, The rotor blade is made of a plurality of metal materials (a first metal material, a second metal material, etc.), and the constituent parts are manufactured by a fused deposition modeling means (such as a 3D printer 280), A vacuum pump characterized in that a reinforcing material (such as reinforcing material 118) made of a second metal material having a higher strength than the first metal material that constitutes the main shape of the rotor blade is arranged in an integrally arranged structure. (2) The vacuum pump according to (1) above, wherein the reinforcing material is arranged in a built-in structure. (3) The vacuum pump according to (1) or (2) above, characterized in that the reinforcing material is arranged so 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, wherein the reinforcing material is arranged so that the second metal material is continuous in the radial direction of the rotor blade. (5) The vacuum pump described in (1) or (2) above, characterized in that the reinforcing material is arranged so that the second metal material is continuous in the rotor axial direction of the rotor blade. (6) A vacuum pump according to claim 1 or 2, characterized in that the reinforcing material is distributed and arranged so that the content of the second metallic material relative to the first metallic material changes from the inner periphery to the outer periphery of the rotor. (7) The part is made of a plurality of metal materials (a first metal material, a second metal material, etc.), and at least some of the components are made by a fused deposition modeling method (such as a 3D printer 280), A vacuum pump component (such as a rotor blade 114) characterized in that a reinforcing material (such as reinforcing material 118) made of a metal material (such as a second metal material) stronger than a metal material (such as a first metal material) that constitutes the main shape is arranged in an integrally arranged structure.

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

[0119] For example, it is possible to form a portion (e.g., the rotating turbine blades 102 and the rotor main body 103a) by fusion deposition modeling means (such as a 3D printer), and form the other portion (e.g., the rotor lower cylindrical portion 103b) by cutting processing. [Explanation of symbols]

[0120] 100: Turbomolecular pump 102 (102a, 102b, 102c...): Rotating turbine blades 103: Rotating body 103a: Rotating body main body 103b: Lower cylindrical part of the rotor 113: Rotor shaft 114: Rotor 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. a rotor blade disposed on a rotor shaft and rotating together with the rotor shaft; A vacuum pump that exhausts gas by an exhaust element provided on the rotor blades as the rotor shaft rotates, The rotor blade is made of a plurality of metal materials, and the constituent parts are manufactured by fused deposition modeling; A vacuum pump characterized in that a reinforcing material, which is a second metal material having a strength higher than that of a first metal material constituting the main shape of the rotor blades, is arranged in an integrally arranged structure.

2. 2. The vacuum pump according to claim 1, wherein the stiffener is arranged in a built-in structure.

3. 3. The vacuum pump according to claim 1, wherein the reinforcing member is disposed so that the second metallic material is continuous in the circumferential direction of the rotor blade.

4. 3. The vacuum pump according to claim 1, wherein the reinforcing member is arranged so that the second metallic material is continuous in the radial direction of the rotor blade.

5. 3. The vacuum pump according to claim 1, wherein the reinforcing member is disposed so that the second metallic material is continuous in the rotor axial direction of the rotor blades.

6. 3. The vacuum pump according to claim 1, wherein the reinforcing material is distributed and arranged such that the content of the second metallic material relative to the first metallic material changes from the inner periphery to the outer periphery of the rotor blade.

7. The part is made of a plurality of metal materials, and at least a part of the part is made by fused deposition modeling; A vacuum pump component comprising a first metal material constituting the main shape and a reinforcing material made of a second metal material having a strength higher than that of the first metal material, the reinforcing material being arranged in an integrally arranged structure.

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