vacuum pump

Abstract

To provide a vacuum pump having a structure which is preferable for support of assembly work, and to provide an assembly method of the vacuum pump and a jig used for the assembly.SOLUTION: A vacuum pump 1 includes a contact part R which contacts with a jig Q used for adjustment of an axial height of a seal member L. During assembly of the vacuum pump 1 in which a pump fixing component J is arranged facing an outer periphery of a rotating body 103, the jig is positioned by the contact part in a state that the pump fixing component is disposed on a base 129 and a pressing part Q1 of the positioned jig presses the pump fixing component in a base direction to adjust the axial height of the seal member L. In the adjustment, the pump fixing component is wholly lowered in the base direction to avoid interference between stationary vanes 123 laminated on the pump fixing component as parts of the pump fixing component and rotor vanes 102 protruding from an outer periphery of the rotating body in a direction of the pump fixing component.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a vacuum pump used as a gas exhaust means for process chambers and other chambers in semiconductor manufacturing equipment, flat panel display manufacturing equipment, and solar panel manufacturing equipment, a method for assembling the same, and a jig used in the assembly, and is particularly suitable for supporting vacuum pump assembly work. [Background technology]

[0002] A conventional vacuum pump of this type is, for example, the vacuum pump described in Patent Document 1. The vacuum pump in this document includes a turbine stage having a structure in which stationary vanes (7) and rotating blades (6) are arranged alternately.

[0003] However, in a conventional vacuum pump having a turbine stage as disclosed in Patent Document 1, the stationary vanes (7) are interposed between the rotor blades (6) adjacent to each other in the vertical direction due to their structure. Therefore, when assembling the vacuum pump, particularly when interposing the stationary vanes (7) between the rotor blades (6), the stationary vanes (7) and the rotor blades (6) may interfere with each other, which may result in damage to the stationary vanes (7) and the rotor blades (6), making the vacuum pump assembly work difficult. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-51952 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made to solve the above-mentioned problems, and its object is to provide a vacuum pump having a structure suitable for supporting vacuum pump assembly work, an assembly method thereof, and a jig used for said assembly. [Means for solving the problem]

[0006] In order to achieve the above object, the vacuum pump according to the present invention includes a base, a rotor disposed on the base, and support means for supporting the rotor rotatably about its axis; disposed on the base facing the outer periphery of the rotor do a pump fixing component, a casing for fixing at least a portion of the pump fixing component on an upper side thereof, and the pump fixing component Underside of and the base Top of A gap formed between A pump is provided between the lower surface of the pump fixing part and the upper surface of the base. a sealing member that seals the gap; provided on the pump fixing component, and when the pump fixing component is not fixed by the casing Axial height of the seal member of adjustment and pressing the pump fixing part downward toward the base to jig The pressing part of abutment and a pressing force for lowering the pump fixing part is received from the pressing part. and a contact portion.

[0007] The vacuum pump according to the present invention teeth , an attachment part attached to the pump stationary part; The abutment portion ,before When installing the above accessories, The pressing portion is brought into contact with the The jig positioned by the position The present invention may be characterized in that the

[0008] A method for assembling a vacuum pump according to the present invention includes assembling a base, a rotor disposed on the base, and support means for supporting the rotor rotatably about its axis, disposed on the base facing the outer periphery of the rotor do a pump fixing component, a casing for fixing at least a portion of the pump fixing component on an upper side thereof, and the pump fixing component Underside of and the base Top of A gap formed between A pump is provided between the lower surface of the pump fixing part and the upper surface of the base. a sealing member that seals the gap; provided on the pump fixing part, when the pump fixing part is not fixed by the casing Axial height of the seal member of adjustment and pressing the pump fixing part downward toward the base to jig The pressing part of abutment and a pressing force for lowering the pump fixing part is received from the pressing part.a step of arranging the pump stationary component facing the outer periphery of the rotor, the step of arranging the pump stationary component on the base as a means for avoiding interference between the stationary vanes stacked on the pump stationary component as a part of the pump stationary component and the moving blades protruding from the outer periphery of the rotor toward the pump stationary component, The pump fixing parts are not fixed to the casing. In this state, the jig is positioned by the abutting portion, and the positioned jig The aforementioned The method includes a first step of adjusting the axial height of the seal member to a first predetermined value by pressing the pump fixing component toward the base with a pressing part; a second step of forming a turbine stage having a structure in which the stator vanes and the rotor blades are alternately arranged by arranging the stator vanes on the pump fixing component after the first step; and a third step of fixing the pump fixing component to the base with the casing after the second step, adjusting the axial height of the seal member to a second predetermined value.

[0009] In the method for assembling a vacuum pump according to the present invention, the first predetermined value may be a dimension value slightly higher than a design dimension value of the sealing member, and the second predetermined value may be the design dimension value of the sealing member.

[0010] In the vacuum pump assembly method according to the present invention, the third step may be characterized in that a gap is formed between the pressing portion of the jig used in the first step and the pump fixing component.

[0011] Furthermore, the jig according to the present invention includes a base, a rotating body arranged on the base, and support means for supporting the rotating body rotatably around its axis; disposed on the base facing the outer periphery of the rotor do a pump fixing component, a casing for fixing at least a portion of the pump fixing component on an upper side thereof, and the pump fixing component Underside of and the base Top of A gap formed between A pump is provided between the lower surface of the pump fixing part and the upper surface of the base. a sealing member that seals the gap; provided on the pump fixing component,a jig used for assembling a vacuum pump, the jig having an abutment portion that abuts against a jig used for adjusting the axial height of the seal member, the jig being configured to place the pump fixing component on the base; The pump fixing parts are not fixed to the casing. In this state, To contact from above and in the positioned state, Contact part Press toward the base and lower the pump fixing part. The present invention is characterized in that it is provided with a pressing portion that adjusts the axial height of the sealing member.

[0012] The jig according to the present invention may be characterized in that, even after adjusting the axial height of the sealing member, the jig is disposed within the pump with a gap formed between the jig and the pump fixing part.

[0013] In the jig according to the present invention, the jig comprises: In a state where the pressing portion is brought into contact with the contact portion and positioned Pump fixing parts Facing the outer surface of The method may be characterized by: [Effects of the Invention]

[0014] In the present invention, as a specific configuration of the vacuum pump, as described above, a configuration is adopted in which an abutting portion that abuts against a jig used for adjusting the axial height of the seal member is provided. Therefore, during assembly of the vacuum pump, for example, when arranging the pump fixing component opposite the outer periphery of the rotor, the jig is positioned by the abutting portion with the pump fixing component disposed on the base, and the axial height of the seal member is adjusted by pressing the pump fixing component toward the base with the pressing portion of the positioned jig, and by lowering the pump fixing component as a whole toward the base through this adjustment, interference between components, specifically, interference between the stator vanes stacked on the pump fixing component as part of the pump fixing component and the moving blades protruding from the outer periphery of the rotor toward the pump fixing component, can be avoided, and a vacuum pump having a structure suitable for supporting vacuum pump assembly work can be provided.

[0015] According to the present invention, a specific method for assembling the above-mentioned vacuum pump employs the first to third steps as described above, and in the first step, as a means for avoiding interference between the stator vanes stacked on the pump fixation component as part of the pump fixation component and the moving blades protruding from the outer periphery of the rotor toward the pump fixation component, a jig is positioned by an abutting portion with the pump fixation component placed on a base, and the pump fixation component is pressed toward the base by the pressing portion of the positioned jig, thereby adjusting the axial height of the seal member to a first predetermined value. Therefore, when forming a turbine stage having a structure in which stator vanes and moving blades are alternately arranged by placing the stator vanes on the pump fixation component after the first step, the above-mentioned interference can be avoided, which is suitable for supporting the vacuum pump assembling work.

[0016] Furthermore, according to the present invention, as a specific configuration of a jig used in assembling the above-mentioned vacuum pump, as described above, the jig is configured to be positioned by the abutment portion with the pump fixing component placed on the base, and to be equipped with a pressing portion that adjusts the axial height of the seal member by pressing the pump fixing component toward the base in the positioned state. Therefore, by adjusting the axial height of the seal member, the pump fixing component can be lowered as a whole toward the base, thereby avoiding interference between components, specifically, interference between the stator vanes stacked on the pump fixing component as part of the pump fixing component and the moving blades that protrude from the outer periphery of the rotor toward the pump fixing component, making the jig suitable for supporting the vacuum pump assembling work. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a vertical cross-sectional view of a vacuum pump called a turbomolecular pump. [Figure 2] Circuit diagram of the amplifier circuit. [Figure 3] FIG. 10 is a time chart showing control when a current command value is greater than a detected value. [Figure 4] FIG. 10 is a time chart showing control when a current command value is smaller than a detected value. [Figure 5]1 is a cross-sectional view of a vacuum pump to which the present invention is applied. [Figure 6] FIG. [Figure 7] An explanatory diagram of the second and third steps. [Figure 8] A part of Figure 7 and its enlarged view. [Figure 9] FIG. 1 is a schematic diagram illustrating the arrangement of a jig to which the present invention is applied relative to a vacuum pump. [Figure 10] Top view of the jig. [Figure 11] Front view of the jig. DETAILED DESCRIPTION OF THE INVENTION

[0018] FIG. 1 is a longitudinal cross-sectional view of a vacuum pump known as a turbomolecular pump, FIG. 2 is a circuit diagram of the amplifier circuit, FIG. 3 is a time chart showing control when the current command value is larger than the detection value, and FIG. 4 is a time chart showing control when the current command value is smaller than the detection value.

[0019] Referring to Fig. 1, in a vacuum pump 100 shown in the figure, an intake port 101 is formed at the upper end of a cylindrical outer cylinder 127. Inside the outer cylinder 127, a rotor 103 (hereinafter referred to as "rotating body 103") is provided, on the periphery of which are formed a plurality of moving blades 102 (102a, 102b, 102c, etc.), which are turbine blades for sucking in and exhausting gas. As a specific example of the configuration of this rotating body 103, in the vacuum pump 100 shown in Fig. 1, the rotating body 103 has a shape in which moving blades 102 are formed on the outer periphery of a first cylindrical portion 102e.

[0020] A rotor shaft 113 is attached to the center of the rotating body 103 via a fastening part CN, and the rotor shaft 113 is supported in the air and its position is controlled by, for example, a five-axis controlled magnetic bearing. In this case, the magnetic bearing and the rotor shaft 113 function as a support means for supporting the rotating body 103 so that it can rotate around its axis. Furthermore, the rotating body 103 is generally made of a metal such as aluminum or an aluminum alloy.

[0021] As a specific example of the magnetic bearing configuration, in the vacuum pump 100 of Fig. 1, the upper radial electromagnets 104 are four electromagnets 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.

[0022] In the 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.

[0023] Rotor shaft 113 is made of a high magnetic permeability material (iron, stainless steel, etc.) and is attracted by the magnetic force of upper radial electromagnet 104. Such adjustment is performed independently in the X-axis direction and the Y-axis direction. In addition, lower radial electromagnet 105 and lower radial sensor 108 are arranged in the same manner as upper radial electromagnet 104 and upper radial sensor 107, and adjust the radial position of the lower side of rotor shaft 113 in the same way as the radial position of the upper side.

[0024] Furthermore, as a specific configuration example of a magnetic bearing, in the vacuum pump 100 of Fig. 1, axial electromagnets 106A and 106B are arranged above and below a circular metal disk 111 provided at the bottom of the rotor shaft 113. The 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 the rotor shaft 113, and an axial position signal is sent to the control device 200.

[0025] 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.

[0026] As described above, the control device 200 appropriately adjusts the magnetic force 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.

[0027] 1, 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.

[0028] 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.

[0029] A plurality of stator vanes 123 (123a, 123b, 123c...) are arranged with a small gap between them and the rotor vanes 102 (102a, 102b, 102c...). Each of the rotor vanes 102 (102a, 102b, 102c...) is formed at an angle of a predetermined degree from a plane perpendicular to the axis of the rotor shaft 113 in order to transport exhaust gas molecules downward through collision. The stator vanes 123 (123a, 123b, 123c...) are made of metal such as aluminum, iron, stainless steel, copper, or an alloy containing any of these metals as an ingredient.

[0030] Similarly, the stator vanes 123 are formed at an inclination at a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113, and are arranged alternately with the rows of the rotor blades 102 toward the inside of the outer casing 127. The outer peripheral ends of the stator vanes 123 are supported in a state where they are inserted between a plurality of stacked stator vane spacers 125 (125a, 125b, 125c, etc.).

[0031] The stator 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 stator vane spacer 125 with a small gap between them. A base 129 is disposed at the bottom of the outer cylinder 127. An exhaust port 133 is formed in the base 129 and communicates with the outside. Exhaust gas that enters the intake port 101 from the chamber (vacuum chamber) and is transferred to the base 129 is sent to the exhaust port 133.

[0032] Furthermore, depending on the application of the vacuum pump 100, a threaded spacer 131 is disposed between the lower part of the stator vane spacer 125 and the base 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 is the direction in which, when exhaust gas molecules move in the rotation direction of the rotor 103, these molecules are transported toward the exhaust port 133. At the lowest part of the rotor 103, next to the rotor blades 102 (102a, 102b, 102c, etc.), a second cylindrical portion 102d is connected to the first cylindrical portion 102e and hangs down. The outer peripheral surface of the second cylindrical portion 102d is cylindrical and protrudes toward the inner peripheral surface of the threaded spacer 131, and is located close to, with a predetermined gap between them, the inner peripheral surface of the threaded spacer 131. The exhaust gas transferred to the thread groove 131a by the rotor blade 102 and the stator blade 123 is sent to the base 129 while being guided by the thread groove 131a.

[0033] The base 129 is a disk-shaped member that forms the base of the vacuum pump 100, and is generally made of metal such as iron, aluminum, stainless steel, etc. The base 129 not only physically holds the vacuum 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.

[0034] In this configuration, when the rotor blades 102 are rotated together with the rotor shaft 113 by the motor 121, the action of the rotor blades 102 and the stator vanes 123 causes exhaust gas to be drawn from the chamber through the inlet 101. The rotational speed of the rotor blades 102 is typically 20,000 rpm to 90,000 rpm, and the peripheral speed at the tip of the rotor blades 102 reaches 200 m / s to 400 m / s. The exhaust gas drawn in through the inlet 101 passes between the rotor blades 102 and the stator vanes 123 and is transported to the base 129. At this time, the temperature of the rotor blades 102 rises due to frictional heat generated when the exhaust gas comes into contact with the rotor blades 102 and conduction of heat generated by the motor 121, but this heat is transferred to the stator vanes 123 by radiation or conduction through gas molecules of the exhaust gas.

[0035] The stator vane spacers 125 are joined together at their outer peripheries, and transfer heat received by the stator vanes 123 from the rotor blades 102 and frictional heat generated when exhaust gas comes into contact with the stator vanes 123 to the outside.

[0036] In the above description, the threaded spacer 131 is disposed on the outer periphery of the cylindrical portion 102d of the rotor 103, and the thread groove 131a is formed on the inner circumferential surface of the threaded spacer 131. However, there are also cases where the thread groove is formed on the outer circumferential surface of the cylindrical portion 102d, and a spacer having a cylindrical inner circumferential surface is disposed around the outer circumferential surface of the cylindrical portion 102d.

[0037] Depending on the application of the vacuum pump 100, the electrical equipment section may be covered with a stator column 122 so that the gas sucked in from the intake port 101 does not enter 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 with purge gas.

[0038] In this case, piping (not shown) is provided in the base 129, and purge gas is introduced through this piping. 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 stator column 122 and the inner cylindrical portion of the rotor blade 102.

[0039] Here, the vacuum pump 100 requires identification of the model and control based on individually adjusted specific parameters (e.g., various characteristics corresponding to the model). To store these control parameters, the vacuum pump 100 is provided with an electronic circuit unit 141 inside its body. The electronic circuit unit 141 is composed of a semiconductor memory such as an EEPROM, electronic components such as semiconductor devices for accessing the memory, and a substrate 143 for mounting these components. The electronic circuit unit 141 is housed below a rotational speed sensor (not shown) near the center of a base 129 that forms the lower part of the vacuum pump 100, and is closed by an airtight bottom lid 145.

[0040] In the semiconductor manufacturing process, some process gases introduced into the chamber have the property of solidifying when their pressure exceeds a predetermined value or their temperature falls below a predetermined value. Inside the vacuum pump 100, the pressure of the exhaust gas is lowest at the inlet 101 and highest at the outlet 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 101 to the outlet 133, the process gas solidifies and adheres to and accumulates inside the vacuum pump 100.

[0041] For example, when SiCl4 is used as the process gas in an Al etching system, the low vacuum (760 [torr] to 10 -2 The vapor pressure curve shows that at low pressures (approximately 20°C) and pressures of 10 ...

[0042] Therefore, in order to solve this problem, conventionally, a heater (not shown) or a circular water-cooled pipe 149 is wrapped around the outer periphery of the base 129, etc., and a temperature sensor (e.g., a thermistor) (not shown) is embedded in the base 129, and the heating of the heater and the cooling by the water-cooled pipe 149 are controlled based on the signal from this temperature sensor to maintain the temperature of the base 129 at a constant high temperature (set temperature) (hereinafter referred to as TMS; Temperature Management System).

[0043] Next, a description will be given of the amplifier circuit 150 that controls excitation of the upper radial electromagnet 104, the lower radial electromagnet 105, and the axial electromagnets 106A and 106B in the vacuum pump 100. A circuit diagram of this amplifier circuit 150 is shown in FIG.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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 vacuum 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] Fig. 5 is a cross-sectional view of a vacuum pump to which the present invention is applied, Fig. 6 is an explanatory diagram of the first step, Fig. 7 is an explanatory diagram of the third step, and Fig. 8 is an enlarged view of a portion of Fig. 7. Also, Fig. 9 is a schematic diagram of the arrangement of a jig to which the present invention is applied relative to the vacuum pump, Fig. 10 is a top view of the jig, and Fig. 11 is a front view of the jig.

[0057] The vacuum pump 1 in Figure 5 includes a base 129, a rotor 103 arranged on the base 129, a support means for supporting the rotor 103 so that it can rotate around its axis, a pump fixing part J arranged opposite the outer periphery of the rotor 103, a casing K for fixing at least a part of the pump fixing part J on its upper side, a gap G1 formed between the pump fixing part J and the base 129, a sealing member L for sealing the gap G1, and an abutment part R for abutting against a jig Q (see Figures 6 to 11) used for adjusting the axial height of the sealing member L.

[0058] In the vacuum pump 1 of Figure 5, the specific configurations of the base 129, the rotating body 103, and the support means are similar to those of the vacuum pump 100 of Figure 1 described above, so the same members are given the same symbols and detailed descriptions thereof are omitted.

[0059] As described above, the pump fixing part J in the vacuum pump 1 in FIG. 5 is a part that is arranged opposite the outer periphery of the rotor 103. Therefore, in the vacuum pump 1 in the same figure, the parts that are arranged in this manner, specifically, at least the stator vanes 123 (123a, 123b...), the stator vane spacers 125 (125a, 125b...), and the threaded spacer 131 correspond to the pump fixing part J.

[0060] In the vacuum pump 1 of FIG. 5, the specific functions of the stator vanes 123, the stator vane spacers 125, and the threaded spacers 131 are similar to those of the vacuum pump 100 of FIG. 1 described above, and therefore the same members are denoted by the same reference numerals and detailed description thereof will be omitted.

[0061] As a specific example of a configuration for supporting the threaded spacer 131, the vacuum pump 1 in Fig. 5 employs a configuration in which the threaded spacer 131 is attached to the top of the heater spacer 300. The heater spacer 300 is also a part that is disposed opposite the outer periphery of the rotor 103, and is therefore a pump fixing part J.

[0062] A plurality of cartridge heaters H (see FIG. 9) are attached to the heater spacer 300. These cartridge heaters H mainly function as a means for heating the threaded spacer 131 by heating the heater spacer 300 to generate heat. As an example of a structure for attaching the cartridge heaters H to the heater spacer 300, the vacuum pump 1 in FIG. 5 employs a structure in which recesses 300A for heater attachment are formed on the outer periphery of the heater spacer 300 and the cartridge heaters H are attached to the recesses 300A, but the present invention is not limited to this structure.

[0063] An insulator wall 301 is attached to the lower part of the heater spacer 300. The insulator wall 301 functions as a means for forming a flow path within the pump that connects the vicinity of the downstream outlet of the thread groove 131a to the exhaust port 131 (see FIG. 1). This insulator wall 301 is also a part that is disposed opposite the outer periphery of the rotor 103, and is therefore a pump fixing part J.

[0064] Furthermore, a cylindrical inner spacer 302 is attached to the upper part of the heater spacer 300. The inner spacer 302 is arranged so as to cover the outer periphery of a stack (in the example of FIG. 5 , the bottom four stages of stator vanes 123 (123d to 123h) and stator vane spacers 125 (125c to 125f)) made up of stator vanes 123 and stator vane spacers 125 stacked on the threaded spacer 131. The inner spacer 302 arranged in this manner is also a component arranged facing the outer periphery of the rotor 103, and is therefore a pump fixing component J.

[0065] As a specific structural example of the contact portion R, the vacuum pump 1 of Figure 1 employs a structure in which a recess R1 is formed on the lower outer periphery of the heater spacer 300, and the pressing portion Q1 of the jig Q engages with this recess R1 (see Figure 6).

[0066] As described above, the contact portion R is used to adjust the axial height of the seal member L, and therefore, its structure can be appropriately modified as needed within the scope of this purpose. Although not shown in the drawings, for example, it is also possible to form the contact portion R as a convex portion, and adopt a structure in which the concave portion of the jig Q engages with this convex portion.

[0067] As a specific example of the configuration of the casing K, in the vacuum pump 1 of Fig. 5, the casing K divides the outer cylinder 127 in the vacuum pump 100 of Fig. 1 into an upper casing K1 and a lower casing K2, and of these, the lower casing K2 has the above-mentioned fixing function. In other words, the lower casing K2 is configured to have the function of fixing at least a part of the pump fixing part J on its upper side.

[0068] The upper casing K1 functions as an exterior of the vacuum pump 1. On the other hand, the lower casing K2 has a structure in which a water-cooled spacer K21 and an outer wall K22 are connected with bolts BT3 (see FIG. 7), and in addition to functioning as an exterior of the vacuum pump 1, it also functions as a means for cooling the vacuum pump 1 by passing a cooling medium through water-cooled pipes (not shown) in the water-cooled spacer K21.

[0069] As a specific example of a configuration in which a portion of the pump fixing part J is fixed by the lower casing K2, the vacuum pump 1 in Fig. 5 employs a configuration in which, at the portion where the lower casing K2 and the inner spacer 302 overlap each other, bolt-through holes are formed on the lower casing 127B side and threaded holes are formed on the inner spacer 302 side, and bolts BT1 (see Fig. 7) are passed through the bolt-through holes and fastened to the threaded holes, but the present invention is not limited to this. The inner spacer 302 may be fixed by other fastening means than the bolts BT1.

[0070] As a specific example of a configuration for attaching and fixing the inner spacer 302 to the heater spacer 300, the vacuum pump 1 in Fig. 5 employs a configuration in which bolt holes are formed in the lower flange portion of the inner spacer 302 and threaded holes are formed in the upper flange portion of the heater spacer 300, and bolts BT2 (see Fig. 7) are passed through the bolt holes and tightened into the threaded holes for fixation, but the present invention is not limited to this. The inner spacer 302 may also be fixed by other fastening means than the bolts BT2.

[0071] The gap G1 is provided between the upper surface of the base 129 and the lower surface of the heater spacer 300 (pump fixing part J) adjacent to and facing it, and between the upper surface of the base 129 and the lower surface of the inner spacer 302 adjacent to and facing it, and functions as an insulating means for preventing heat transfer between the base 129 and the heater spacer 300 or the inner spacer 302.

[0072] 1, the inner spacer 302, heater spacer 300, threaded spacer 131, insulator wall 301, the bottom four stages of stator vanes 123 (123e to 123h) and stator vane spacers 125 (125c to 125f) are configured as a single integrated internal unit M, and this internal unit M is heated by heat generated by the heater spacer 300 to prevent deposits from forming in the thread grooves 131a, etc. The gap G1 functions as a means for preventing the heat from escaping from the internal unit toward the base 129.

[0073] The sealing member L functions as a means for isolating the interior of the vacuum pump 1 from the atmosphere by being interposed in the gap G1, i.e., between the base 129 and the internal unit M (specifically, between the upper surface of the base 129 and the lower surface of the heater spacer 300).

[0074] 1, the vacuum pump 1 employs a configuration in which an insulator N is disposed on the base 129 and the seal member L is disposed on the insulator N, as a specific configuration for interposing the seal member L in the gap G1, but the configuration is not limited to this. The insulator N may also be omitted.

[0075] The insulator N has a partially raised shape, and the tip of the raised portion N1 serves as an abutment portion that abuts against the inner periphery of the lower part of the heater spacer 300, while the other end abuts against a step portion of the base 129, thereby functioning as a radial positioning means for the heater spacer 300. Furthermore, by arranging the sealing member L in abutment against the raised portion N1 of the insulator N, the insulator N also functions as a radial positioning means for the sealing member N.

[0076] 6, the jig Q is positioned by the aforementioned contact portion R in a state where the pump fixing part J (specifically, the heater spacer 300) is placed on the base 129. The positioning of the jig Q by this contact portion R occurs when the pressing portion Q1 of the jig Q engages with the recessed portion R1 of the heater spacer 300 described above.

[0077] The pressing portion Q1 of the jig Q functions as a means for adjusting the axial height of the seal member L by pressing the pump fixing part J (specifically, the heater spacer 300) toward the base 129 while positioned as described above.

[0078] Referring to Figure 9, in the vacuum pump 1 of Figure 5, the specific arrangement configuration of the abutment portion R is such that the abutment portion R is arranged in the same phase as the accessory part (cartridge heater H in the examples of Figures 5 and 9) attached to the pump fixing part J.

[0079] Therefore, the jig Q positioned by the abutment portion R interferes with the cartridge heater H, which is an accessory, when the cartridge heater H is attached. Unless the jig Q is removed, the cartridge heater H cannot be attached, so it is possible to effectively prevent the jig Q from being forgotten.

[0080] The cartridge heater H is an example of an accessory. The jig Q may be configured so that it interferes with an accessory other than the cartridge heater H.

[0081] When assembling the vacuum pump 1 of Fig. 5, the rotor 103 is placed on the base 129, and then the pump fixing part J is placed opposite the outer periphery of the rotor 103. The placement of the pump fixing part J here is such that the inner spacer 302, the heater spacer 300, and the threaded spacer 131 are placed on the base 129 as shown in Fig. 6, and the steps for placing them in this manner are as follows: steps 1 to 3.

[0082] <<First step>> 6, in the first step, the insulator N is attached to the base 129, and the seal member L is placed on the attached insulator N. Then, the insulator wall 301, the heater spacer 300, and the threaded spacer 131 are placed on the base 129 in a stacked state in that order.

[0083] As a result, the insulator wall 301, the heater spacer 300, and the threaded spacer 131 are arranged opposite to the outer periphery of the rotating body 103 (for convenience of explanation, the rotating body 103 shown in FIG. 8 is omitted in FIG. 6).

[0084] As described above, the insulator wall 301, heater spacer 300, and threaded spacer 131 are arranged facing each other on the outer periphery of the rotating body 103, and the lower surface of the heater spacer 300 abuts against the seal member L. The thickness of the seal member L forms a predetermined gap G1 between the base 129 and the insulator wall 301, and between the base 129 and the heater spacer 300. Furthermore, the inner periphery of the lower part of the heater spacer 300 contacts the tip of the rising portion N1 of the insulator N, thereby positioning the heater spacer 300, inner spacer 302, and threaded spacer 131 in the radial direction.

[0085] At this stage, it is not possible to arrange the stator vanes 123 on the pump fixing part J by alternately stacking the stator vanes 123 and the stator vane spacers 125 on the heater spacer 300. The reason for this is that the stator vanes 123 stacked on the pump fixing part J as part of the pump fixing part J will interfere with the rotor blades 102 protruding from the outer periphery of the rotor 103 toward the pump fixing part J.

[0086] Therefore, in the first step, with the insulator wall 301, heater spacer 300, and threaded spacer 131 placed on the base 129 as described above, a jig Q is placed on the outer periphery of the heater spacer 300, and the height of the jig Q is positioned by the abutting portion R of the heater spacer 300. This positioning is performed by fitting the pressing portion Q1 of the jig Q into the recess R1 of the heater spacer 300.

[0087] Then, by pressing the heater spacer 300 toward the base 129 with the pressing portion Q1 of the jig Q positioned as described above, the axial height of the seal member L is adjusted to a first predetermined value. This first predetermined value is a dimension value slightly higher than the design dimension value of the seal member L. The pressing may be performed using the handle Q2 of the jig Q.

[0088] The pressure causes the inner spacer 302, heater spacer 300, and threaded spacer 131 to move downward as a whole toward the base 129, thereby making it possible to avoid the interference described above, and by stacking the stator vanes 123 and stator vane spacers 125 alternately on the heater spacer 300, it becomes possible to arrange the stator vanes 123 on the pump fixing part J.

[0089] <<Second step>> In the second step, after the first step, the stator vanes 123 (123d to 123h) are arranged on the pump fixing part J (see Figure 7), thereby forming a turbine stage having a structure in which the stator vanes 123 and the rotor blades 102 are arranged alternately.

[0090] The arrangement of the stator vanes 123 on the pump fixing part J is such that the bottom four rows of stator vanes 123 (123d to 123h) and stator vane spacers 125 (125c to 125f) are alternately stacked on the heater spacer 300 in layers in FIG.

[0091] After the stator vanes 123 and stator vane spacers 125 are stacked in layers as described above, in this second process, the inner spacer 302 is attached and fixed with bolts BT2 so as to cover the outer periphery of the stack (see Figure 7), thereby fixing the stack (stator vanes 123 and stator vane spacers 125) in the axial direction.

[0092] <<Third Process>> 7, in the third step, after the second step, the casing K is placed on the base 129, and the pump fixing part J is fixed to the base 129 using the placed casing K. The fixing force further presses the seal member L toward the base 129, thereby adjusting the axial height of the seal member L to a second predetermined value. The second predetermined value is the design dimension value of the seal member L.

[0093] In this third step, "placing the casing K on the base 129" specifically means screwing the lower casing K2 onto the base 129 with bolts (not shown). Furthermore, "fixing the pump fixing part J to the base 129 with the casing K" specifically means connecting and fixing the lower casing K2 and the inner spacer 302 with the bolts BT2. Then, by tightening the bolts BT2, the seal member L is compressed, and its axial height is adjusted to the designed dimension value (second predetermined value).

[0094] 8, in this third step, a predetermined gap G2 is formed between the pressing portion Q1 of the jig Q used in the first step and the pump fixing part J (specifically, the contact portion R of the heater spacer 300). This makes it possible to remove the jig Q later.

[0095] 《Final process》 In the final step, after the third step, the above-mentioned turbine stage is completed, that is, the stator vanes 123 for the three stages from the top and the stator vane spacers 125 for the two stages from the top in FIG. 5 are alternately stacked, and then the upper casing K1 is placed around the outer periphery of the turbine stage, and the placed upper casing K1 and lower casing K2 are connected with bolts (not shown), thereby completing the basic assembly work of the vacuum pump.

[0096] Other Embodiments Referring to Figure 5, the jig Q described above has been removed from the vacuum pump 1, but in another embodiment, the jig Q may be arranged in a manner that it remains in the vacuum pump 1 with a gap G2 formed between it and the pump fixing part J even after the axial adjustment of the seal member L.

[0097] Specifically, the handle Q2 of the jig Q shown in the figure is replaced with a bolt of a length that does not interfere with the cartridge heater H, an accessory part, when installing the cartridge heater H. This allows the vacuum pump assembly work to be completed without removing the jig Q.

[0098] If the jig Q is left inside the vacuum pump 1 as described above, there is an advantage in that the convenience of the assembly work is improved, for example, when the vacuum pump 1 is overhauled, the jig Q can be used again to reassemble the vacuum pump.

[0099] As a specific configuration of the vacuum pump 1 of this embodiment described above, as described above, a configuration is adopted in which the abutting portion R abuts against the jig Q used for adjusting the axial height of the seal member L. For this reason, during assembly of the vacuum pump, for example, when arranging the pump fixing part J opposite the outer periphery of the rotor 103, the jig Q is positioned by the abutting portion R in a state in which the pump fixing part J is arranged on the base 129, and the pressing portion Q1 of the positioned jig Q presses the pump fixing part J toward the base 129, thereby adjusting the axial height of the seal member L, and by lowering the pump fixing part J entirely toward the base 129 through this adjustment, interference between parts, specifically, interference between the stator vanes 123 stacked on the pump fixing part J as part of the pump fixing part J and the moving blades 102 protruding from the outer periphery of the rotor 103 toward the pump fixing part J, can be avoided, and this configuration is suitable for supporting the vacuum pump assembly work.

[0100] Furthermore, as described above, the vacuum pump assembling method of this embodiment employs the first to third steps, and in the first step, as a means for avoiding interference between the stator vanes 123 stacked on the pump fixing part J as part of the pump fixing part J and the moving blades 102 protruding from the outer periphery of the rotor 103 toward the pump fixing part J, the jig Q is positioned by the abutting part R with the pump fixing part J placed on the base 129, and the pump fixing part J is pressed toward the base 129 by the pressing part Q1 of the positioned jig Q, thereby adjusting the axial height of the seal member L to a first predetermined value. Therefore, when forming a turbine stage having a structure in which the stator vanes 123 and the moving blades 102 are alternately arranged by placing the stator vanes 123 on the pump fixing part J after the first step, the interference can be avoided, which is suitable for supporting the vacuum pump assembling work.

[0101] As a specific configuration of the jig of this embodiment, as described above, the jig Q is positioned by the abutting portion R in a state where the pump fixing part J is placed on the base 129, and is provided with a pressing portion Q1 that adjusts the axial height of the seal member L by pressing the pump fixing part J toward the base 129 in the positioned state. Therefore, by adjusting the axial height of the seal member L, the pump fixing part J can be lowered as a whole toward the base 129, thereby avoiding interference between parts, specifically, interference between the stator vanes 123 stacked on the pump fixing part J as part of the pump fixing part J and the moving blades 102 that protrude from the outer periphery of the rotor 103 toward the pump fixing part J, making this jig suitable for supporting vacuum pump assembly work.

[0102] The embodiments and modifications of the present invention may be combined as needed.

[0103] The present invention is not limited to the above-described embodiments, and many modifications can be made by those skilled in the art within the scope of the technical concept of the present invention. [Explanation of symbols]

[0104] 100 Vacuum Pump 101 Air intake 102 Moving blade 102d Second cylindrical section 102e First cylindrical portion 103 Rotating body (rotor) 104 Upper radial electromagnet 105 Lower radial electromagnet 106A, 106B Axial electromagnet 107 Upper radial sensor 108 Lower radial sensor 109 Axial Sensor 111 Metal Disc 113 Rotor shaft 120 Protective Bearing 121 Motor 122 Stator column 123 Stator vane (pump fixing part) 125 Stator vane spacer (pump fixing part) 127 Outer cylinder 129 base 131 Threaded spacer (pump fixing part) 131a screw groove 133 Exhaust port 141 Electronic circuit section 149 Water cooled pipe 143 PCB 145 Bottom lid 150 Amplifier Circuit 171 Power supply 181 Current detection circuit 191 Amplifier control circuit 200 control device 300 Heater spacer (pump fixing part) Recess for mounting a 300A heater 301 Insulator wall (pump fixing part) 302 Inner spacer CN fastening part H Cartridge heater (accessory) J Pump Fixing Parts K casing K1 upper casing K2 Lower casing K21 Water Cooling Spacer K22 Outer Wall L sealing material M Internal Unit N insulator Q Jig Q1 Pressing part Q2 Handle R Contact part BT1, BT2, BT3 bolts G1 Clearance between pump fixing parts and base G2 Gap between the pressing part of the jig and the pump fixing part

Claims

1. With the base, a rotating body disposed on the base; a support means for supporting the rotor so that the rotor can rotate about its axis; a pump fixing component disposed on the base and facing an outer periphery of the rotor; a casing for fixing at least a portion of the pump stationary component on its upper side; a gap formed between a lower surface of the pump fixing component and an upper surface of the base; a seal member interposed between the lower surface of the pump fixing component and the upper surface of the base to seal the gap; a contact portion that is provided on the pump fixing component and that receives a pressure from above from a pressing portion of a jig that presses the pump fixing component toward the base to lower the pump fixing component in order to adjust the axial height of the seal member when the pump fixing component is not fixed to the casing, and that receives a pressure from the pressing portion to lower the pump fixing component. A vacuum pump characterized by:

2. An accessory part attached to the pump fixing part, The abutting portion is provided at a position where the jig, which is positioned by abutting the pressing portion against the abutting portion when attaching the accessory, interferes with the accessory.

2. The vacuum pump according to claim 1,

3. With the base, a rotating body disposed on the base; a support means for supporting the rotor so that the rotor can rotate about its axis; a pump fixing component disposed on the base and facing an outer periphery of the rotor; a casing for fixing at least a portion of the pump stationary component on its upper side; a gap formed between a lower surface of the pump fixing component and an upper surface of the base; a seal member interposed between the lower surface of the pump fixing component and the upper surface of the base to seal the gap; a contact portion that is provided on the pump fixing component and that receives a pressing force from above from a pressing portion of a jig that presses the pump fixing component toward the base to lower the pump fixing component in order to adjust the axial height of the seal member when the pump fixing component is not fixed to the casing, and that receives a pressing force from the pressing portion to lower the pump fixing component, The step of arranging the pump fixing part facing the outer periphery of the rotating body includes: a first step of positioning the jig by the abutting portion while the pump fixing component is disposed on the base and not fixed by the casing, and pressing the pump fixing component toward the base with the pressing portion of the positioned jig, as a means for avoiding interference between the stator vanes stacked on the pump fixing component as a part of the pump fixing component and the moving blades protruding from the outer periphery of the rotor toward the pump fixing component; and a second step of forming a turbine stage having a structure in which the stator vanes and the rotor blades are alternately arranged by arranging the stator vanes on the pump stationary component after the first step; and a third step of, after the second step, fixing the pump fixing component to the base with the casing, thereby adjusting the axial height of the seal member to a second predetermined value. A method for assembling a vacuum pump, comprising:

4. the first predetermined value is a dimension value slightly higher than a design dimension value of the seal member, The second predetermined value is a design dimension value of the seal member.

4. The method for assembling a vacuum pump according to claim 3,

5. In the third step, a gap is formed between the pressing portion of the jig used in the first step and the pump fixing component.

5. A method for assembling a vacuum pump according to claim 3 or 4, characterized in that:

6. With the base, a rotating body disposed on the base; a support means for supporting the rotor so that the rotor can rotate about its axis; a pump fixing component disposed on the base and facing an outer periphery of the rotor; a casing for fixing at least a portion of the pump stationary component on its upper side; a gap formed between a lower surface of the pump fixing component and an upper surface of the base; a seal member interposed between the lower surface of the pump fixing component and the upper surface of the base to seal the gap; a contact portion provided on the pump fixing component and adapted to contact a jig used for adjusting the axial height of the seal member; A jig used in assembling a vacuum pump comprising: The jig positions the pump fixing component by placing it on the base and abutting it from above on the abutting portion in a state where the pump fixing component is not fixed by the casing, and includes a pressing portion that adjusts the axial height of the seal member by pressing the abutting portion toward the base in a positioned state to lower the pump fixing component. A jig characterized by:

7. The jig is disposed in the pump with a gap formed between the jig and the pump fixing component even after adjusting the axial height of the seal member. The jig according to claim 6 .

8. The jig is positioned by abutting the pressing portion against the abutting portion, and faces the outer circumferential surface of the pump fixing component. The jig according to claim 6 .

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