Vacuum pump and control device

Abstract

A vacuum pump and a control device that collect state information of the vacuum pump at appropriate timings are obtained. In the control device (200), the control sections (201, 202, 204) control the action states of the internal devices (a motor (121), a heater, a cooling valve, and the like) arranged in the vacuum pump main body. The information collection section (207) collects the state information of the vacuum pump main body, and the record processing section (208) records the state information collected by the information collection section (207) in a nonvolatile memory (209). Furthermore, the information collection section (207) collects the state information of the vacuum pump main body at the timings at which the action states of the internal devices are switched by the control sections (201, 202, 204).

Description

Vacuum pump and control device Technical Field

[0001] This invention relates to a vacuum pump and a control device. Background Technology

[0002] A monitoring device for a certain vacuum pump (a) determines whether the vacuum pump is in a gas inflow state based on the time change of the motor current value and rotation speed of the vacuum pump, and (b) stores the basic temperature dataset collected at a predetermined period in a storage unit during the period when the vacuum pump is in a gas inflow state (for example, see Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent document 1: Japanese Patent Application Publication No. 2017-194040. Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The vacuum pump status information collected as described above is sometimes used for cause analysis when the vacuum pump malfunctions.

[0008] Generally, status information is stored in a specific memory area of ​​non-volatile memory. However, since only a predetermined number of the latest status information data from the periodically obtained status information data is retained in non-volatile memory, the status of the vacuum pump can only be grasped for a specific period (the product of the collection period and the aforementioned predetermined number) based on the retained status information data, which may prevent proper cause analysis. That is, if the collection period is too short relative to the period during which an event caused by a certain cause occurs, it is possible that only a part of the event can be grasped. Furthermore, if the collection period is too long relative to the period during which an event caused by a certain cause occurs, it is possible that the occurrence of the event itself cannot be grasped, or only a fragment of the event can be grasped.

[0009] In this case, the status information of the vacuum pump may not be collected at the appropriate time.

[0010] The present invention was made in view of the above-mentioned problems, and its object is to provide a vacuum pump and control device that collects the status information of the vacuum pump at appropriate timing.

[0011] Solution for solving the problem

[0012] The vacuum pump of the present invention includes: an internal device disposed in a vacuum pump body; a control unit for controlling the operating state of the internal device; an information collection unit for collecting state information of the vacuum pump body; and a recording and processing unit for recording the state information collected by the information collection unit in a non-volatile memory. Furthermore, the information collection unit collects the state information of the vacuum pump body at a timing point when the operating state of the internal device is switched by the control unit.

[0013] The control device of the present invention includes: a control unit for controlling the operating state of internal devices disposed in a vacuum pump body; an information collection unit for collecting state information of the vacuum pump body; and a recording and processing unit for recording the state information collected by the information collection unit in a non-volatile memory. Furthermore, the information collection unit collects the state information of the vacuum pump body at a timing point when the operating state of the internal devices is switched by the control unit.

[0014] Invention Effects

[0015] According to the present invention, a vacuum pump and a control device are available that can collect status information of the vacuum pump at appropriate timing.

[0016] The above and other objects, features and advantages of the present invention will become more apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0017] Figure 1 is a longitudinal sectional view of a turbomolecular pump according to an embodiment of the present invention;

[0018] Figure 2 is the circuit diagram of the amplifier circuit;

[0019] Figure 3 is a timing diagram showing the control when the current command value is greater than the detection value;

[0020] Figure 4 is a timing diagram showing the control when the current command value is less than the detection value;

[0021] Figure 5 is a block diagram showing the structure of the control device for controlling the turbomolecular pump (vacuum pump) shown in Figure 1;

[0022] Figure 6 is a diagram illustrating an example of the state transition of the turbomolecular pump (vacuum pump) shown in Figure 1;

[0023] Figure 7 is a diagram (1 / 2) illustrating the information collection timing of the control device shown in Figure 5.

[0024] Figure 8 is a diagram (2 / 2) illustrating the information collection timing of the control device shown in Figure 5. Detailed Implementation

[0025] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0026] Figure 1 shows a longitudinal sectional view of the turbomolecular pump 100. In Figure 1, the turbomolecular pump 100 has an intake port 101 formed at the upper end of a cylindrical outer cylinder 127. Furthermore, inside the outer cylinder 127 is a rotating body 103, which has multiple rotating blades 102 (102a, 102b, 102c…) arranged radially and in multiple stages around its periphery, serving as turbine blades for drawing and expelling gas. A rotor shaft 113 is mounted at the center of the rotating body 103, which is suspended in the air and its position controlled, for example, using a 5-axis controlled magnetic bearing.

[0027] The four upper radial electromagnets 104 are arranged in pairs along the X and Y axes. Near each of the upper radial electromagnets 104, four upper radial sensors 107 are provided. The upper radial sensors 107, for example, are inductive sensors or eddy current sensors with conductive windings, and detect the position of the rotor shaft 113 based on the change in inductance of the conductive windings that corresponds 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 transmit this displacement to a control device (not shown).

[0028] In this control device, for example, a compensation circuit with PID regulation function generates an excitation control command signal for the upper radial electromagnet 104 based on the position signal detected by the upper radial sensor 107. The amplifier circuit 150 (described later) performs excitation control on the upper radial electromagnet 104 based on the excitation control command signal, thereby adjusting the radial position of the upper side of the rotor shaft 113.

[0029] Furthermore, the rotor shaft 113 is formed of a high-permeability material (iron, stainless steel, etc.) and is attracted by the magnetic force of the upper radial electromagnet 104. Such adjustments are performed independently in the X-axis and Y-axis directions, respectively. In addition, the lower radial electromagnet 105 and the lower radial sensor 108 are configured in the same way as the upper radial electromagnet 104 and the upper radial sensor 107, and the lower radial position of the rotor shaft 113 is adjusted in the same way as the upper radial position.

[0030] Furthermore, axial electromagnets 106A and 106B are arranged to sandwich a circular metal disk 111 located at the lower part of the rotor shaft 113. The metal disk 111 is made of a high magnetic permeability material such as iron. An axial sensor 109 is provided to detect the axial displacement of the rotor shaft 113, and is configured such that its axial position signal is sent to the control device.

[0031] Furthermore, in the control device, for example, a compensation circuit with PID regulation function generates excitation control command signals for axial electromagnets 106A and 106B based on the axial position signal detected by the axial sensor 109. The amplifier circuit 150 performs excitation control on axial electromagnets 106A and 106B based on these excitation control command signals. As a result, axial electromagnet 106A uses magnetic force to attract metal disk 111 upwards, and axial electromagnet 106B attracts metal disk 111 downwards, thereby adjusting the axial position of rotor shaft 113.

[0032] In this way, the control device appropriately adjusts the magnetic force applied by the axial electromagnets 106A and 106B to the metal disk 111, so that the rotor shaft 113 is magnetically levitated axially and held in space in a non-contact manner. Furthermore, the amplifier circuit 150 that performs excitation control on these upper radial electromagnets 104, lower radial electromagnets 105, and axial electromagnets 106A and 106B will be described later.

[0033] On the other hand, the motor 121 has a plurality of magnetic poles arranged circumferentially around the rotor shaft 113. Each magnetic pole is controlled by a control device to drive the rotor shaft 113 to rotate via an electromagnetic force acting between the rotor shaft 113 and the control device. In addition, a rotational speed sensor (not shown), such as a Hall element, a resolver, or an encoder, is assembled in the motor 121, and the rotational speed of the rotor shaft 113 is detected using the detection signal from the rotational speed sensor.

[0034] Furthermore, for example, a phase sensor (not shown) is installed near the lower radial sensor 108 to detect the phase of rotation of the rotor shaft 113. In the control device, the detection signals from both the phase sensor and the rotational speed sensor are used simultaneously to detect the position of the magnetic poles.

[0035] Multiple fixed wings 123a, 123b, 123c... are provided with a small gap between them and the rotating blades 102 (102a, 102b, 102c...). The rotating blades 102 (102a, 102b, 102c...) are each formed at a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113, so as to use collision to move the molecules of exhaust gas downward.

[0036] Furthermore, the fixed wing 123 is also formed at a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113, and is arranged alternately with the rotating wing 102 toward the interior of the outer cylinder 127. Moreover, the outer peripheral end of the fixed wing 123 is supported in a state of being inserted between a plurality of stacked fixed wing spacers 125 (125a, 125b, 125c...).

[0037] The fixed wing spacer 125 is an annular component, made of metals such as aluminum, iron, stainless steel, copper, or alloys containing these metals. An outer cylinder 127 is fixed to the outer periphery of the fixed wing spacer 125 with a small gap. A base portion 129 is provided at the bottom of the outer cylinder 127. An exhaust port 133 is formed in the base portion 129, communicating with the outside. Exhaust gas transferred to the base portion 129 is sent to the exhaust port 133.

[0038] Furthermore, according to the application of the turbomolecular pump 100, a threaded spacer 131 is provided between the lower part of the fixed wing spacer 125 and the base part 129. The threaded spacer 131 is a cylindrical component made of metals such as aluminum, copper, stainless steel, iron, or alloys composed of these metals, and has a plurality of helical threaded grooves 131a engraved on its inner circumferential surface. The helical direction of the threaded grooves 131a is the direction in which the molecules of the exhaust gas are moved toward the exhaust port 133 when they move along the rotation direction of the rotating body 103. A cylindrical part 102d hangs down from the lowest part of the rotating wing 102 (102a, 102b, 102c...) of the rotating body 103. The outer circumferential surface of the cylindrical part 102d is cylindrical and extends toward the inner circumferential surface of the threaded spacer 131, approaching the inner circumferential surface of the threaded spacer 131 with a predetermined gap. The exhaust gas, which is moved to the threaded groove 131a by the rotating blade 102 and the fixed blade 123, is guided by the threaded groove 131a and sent to the base part 129.

[0039] The base portion 129 is a disc-shaped component that forms the base of the turbomolecular pump 100, and is generally made of metals such as iron, aluminum, and stainless steel. The base portion 129 physically holds the turbomolecular pump 100 and also serves as a heat conduction path; therefore, metals such as iron, aluminum, and copper, which have rigidity and high thermal conductivity, are preferably used.

[0040] In this structure, when the rotating blade 102 and the rotor shaft 113 are driven to rotate by the motor 121, exhaust gas is drawn from the chamber through the intake port 101 by the action of the rotating blade 102 and the fixed blade 123. The exhaust gas drawn from the intake port 101 is transferred to the base portion 129 between the rotating blade 102 and the fixed blade 123. At this time, the temperature of the rotating blade 102 rises due to frictional heat generated when the exhaust gas contacts the rotating blade 102, conduction of heat generated by the motor 121, etc. However, this heat is transferred to the fixed blade 123 side through radiation or conduction by gas molecules of the exhaust gas.

[0041] The fixed wing spacers 125 are joined together on the outer periphery to transfer heat received by the fixed wing 123 from the rotating wing 102, frictional heat generated when the exhaust gas comes into contact with the fixed wing 123, and so on to the outside.

[0042] Furthermore, as described above, the threaded spacer 131 is disposed on the outer periphery of the cylindrical portion 102d of the rotating body 103, and a threaded groove 131a is engraved on the inner peripheral surface of the threaded spacer 131. However, there are also cases where, conversely, a threaded groove is engraved on the outer peripheral surface of the cylindrical portion 102d, and a spacer with a cylindrical inner peripheral surface is disposed around it.

[0043] Furthermore, depending on the application of the turbomolecular pump 100, the following situation also exists: In order to prevent the gas drawn in from the intake port 101 from intruding into the electrical assembly consisting 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., the electrical assembly is surrounded by a stator column 122, and the stator column 122 is maintained at a specified pressure by purified gas.

[0044] In this case, a pipe (not shown) is provided on the base portion 129, through which purified gas is introduced. The introduced purified gas is sent to the exhaust port 133 through the 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 circumferential cylindrical portion of the rotating blade 102.

[0045] Here, the turbomolecular pump 100 requires model identification and control based on inherent parameters (e.g., characteristics corresponding to the model) that are adjusted accordingly. To store these control parameters, the turbomolecular pump 100 includes an electronic circuit section 141 within its main body. The electronic circuit section 141 comprises a semiconductor memory such as an EEP-ROM, electronic components such as semiconductor elements for accessing these components, and a mounting substrate 143. This electronic circuit section 141 is housed below, for example, a rotational speed sensor (not shown) near the center of the base section 129 constituting the lower part of the turbomolecular pump 100, and is closed by an airtight bottom cover 145.

[0046] However, in the semiconductor manufacturing process, the process gas introduced into the chamber contains a type of process gas that becomes solid when its pressure is higher than a specified value or its temperature is lower than a specified value. Inside the turbomolecular pump 100, the pressure of the exhaust gas is lowest at the intake port 101 and highest at the exhaust port 133. During the process gas's journey from the intake port 101 to the exhaust port 133, if its pressure is higher than a specified value or its temperature is lower than a specified value, the process gas becomes solid and accumulates inside the turbomolecular pump 100.

[0047] For example, according to the vapor pressure curve, when SiCl4 is used as the process gas in an Al etching apparatus, under low vacuum (760 tor), -2At low temperatures (approximately 20°C), solid products (e.g., AlCl3) precipitate and accumulate inside the turbomolecular pump 100. Therefore, if process gas precipitates accumulate inside the turbomolecular pump 100, these deposits can narrow the pump flow path and reduce the performance of the turbomolecular pump 100. Furthermore, the aforementioned products are prone to solidification and adhesion in high-pressure areas near the exhaust port or the threaded spacer 131.

[0048] Therefore, in order to solve this problem, conventionally, a heater (not shown) or an annular water-cooling pipe 149 is wound around the outer periphery of the base portion 129, etc., and a temperature sensor (not shown) (e.g., a thermistor) is embedded in the base portion 129, for example. The heating of the heater or the cooling of the water-cooling pipe 149 is controlled based on the signal of the temperature sensor (hereinafter referred to as TMS; TMS: Temperature Management System) so as to maintain the temperature of the base portion 129 at a certain high temperature (set temperature).

[0049] Next, regarding the turbomolecular pump 100 configured in this way, an amplifier circuit 150 for excitation control of its upper radial electromagnet 104, lower radial electromagnet 105, and axial electromagnets 106A and 106B will be described. A circuit diagram of this amplifier circuit is shown in Figure 2.

[0050] In Figure 2, one end of the electromagnet winding 151, which constitutes the upper radial electromagnet 104, is connected to the positive terminal 171a of the power supply 171 via transistor 161. The other end is connected to the negative terminal 171b of the power supply 171 via current detection circuit 181 and transistor 162. Furthermore, transistors 161 and 162 are so-called power MOSFETs, having a structure in which a diode is connected between its source and drain.

[0051] At this time, the cathode terminal 161a of the diode of transistor 161 is connected to the positive terminal 171a, and the anode terminal 161b is connected to one end of the electromagnet winding 151. In addition, the cathode terminal 162a of the diode of transistor 162 is connected to the current detection circuit 181, and the anode terminal 162b is connected to the negative terminal 171b.

[0052] On the other hand, the cathode terminal 165a of the diode 165 used for current regeneration is connected to one end of the electromagnet winding 151, and its anode terminal 165b is connected to the negative terminal 171b. Similarly, the cathode terminal 166a of the diode 166 used for current regeneration is connected to the positive terminal 171a, and its anode terminal 166b is connected to the other end of the electromagnet winding 151 via the current detection circuit 181. Furthermore, the current detection circuit 181 is, for example, composed of a Hall effect current sensor or a resistive element.

[0053] The amplifier circuit 150 configured as described above corresponds to one electromagnet. Therefore, with 5-axis control of the magnetic bearing and a total of 10 electromagnets 104, 105, 106A, and 106B, the same amplifier circuit 150 is configured for each electromagnet, and 10 amplifier circuits 150 are connected in parallel to the power supply 171.

[0054] Furthermore, the amplifier control circuit 191 is, for example, composed of a digital signal processor (hereinafter referred to as the DSP unit) of the control device (not shown), which switches the transistors 161 and 162 on / off.

[0055] The amplifier control circuit 191 compares the current value detected by the current detection circuit 181 (the signal reflecting this current value is called the current detection signal 191c) with a predetermined current command value. Then, based on the comparison result, it determines the magnitude of the pulse width (pulse width times Tp1 and Tp2) occurring within a control loop Ts, which is one cycle of PWM control. As a result, gate drive signals 191a and 191b with this pulse width are output from the amplifier control circuit 191 to the gate terminals of transistors 161 and 162.

[0056] Furthermore, when the rotating body 103 accelerates through a resonance point or experiences external disturbances during constant-speed operation, high-speed and powerful position control of the rotating body 103 is required. Therefore, a high voltage of approximately 50V is used as the power supply 171 to allow the current flowing through the electromagnet winding 151 to increase (or decrease) dramatically. In addition, to stabilize the power supply 171, a capacitor (not shown) is typically connected between the positive terminal 171a and the negative terminal 171b of the power supply 171.

[0057] In this structure, if transistors 161 and 162 are turned on, the current flowing through the electromagnet winding 151 (hereinafter referred to as electromagnet current iL) increases; if they are turned off, the electromagnet current iL decreases.

[0058] Furthermore, if one of transistors 161 and 162 is turned on while the other is turned off, a freewheeling current is maintained. Moreover, by allowing this freewheeling current to flow through the amplifier circuit 150, hysteresis losses in the amplifier circuit 150 can be reduced, thus lowering the overall power consumption of the circuit. Furthermore, by controlling transistors 161 and 162 in this way, high-frequency noise such as harmonics generated in the turbomolecular pump 100 can be reduced. Furthermore, by measuring this freewheeling current using the current detection circuit 181, the electromagnet current iL flowing in the electromagnet winding 151 can be detected.

[0059] That is, when the detected current value is less than the current command value, as shown in Figure 3, in the control loop Ts (e.g., 100 μs), transistors 161 and 162 are turned on only once for a period of time equivalent to the pulse width time Tp1. Therefore, during this period, the electromagnet current iL increases from the positive terminal 171a to the negative terminal 171b toward the current value iLmax (not shown) that can flow through transistors 161 and 162.

[0060] On the other hand, if the detected current value is greater than the current command value, as shown in Figure 4, in the control loop Ts, transistors 161 and 162 are turned off only once for a period of time equivalent to the pulse width time Tp2. Therefore, during this period, the electromagnet current iL decreases from the negative terminal 171b to the positive terminal 171a towards the current value iLmin (not shown) that can be regenerated via diodes 165 and 166.

[0061] Furthermore, in both cases, either transistor 161 or 162 is turned on after pulse width times Tp1 and Tp2. Therefore, a continuous current is maintained in the amplifier circuit 150 during this period.

[0062] The turbomolecular pump 100 described above is an example of a vacuum pump. Furthermore, the control device described above has the functions described later. Figure 5 is a block diagram showing the structure of the control device 200 that controls the turbomolecular pump (vacuum pump) shown in Figure 1.

[0063] The control device 200 shown in Figure 5 includes a magnetic bearing control unit 201, a motor drive control unit 202, a temperature measurement unit 203, an output control unit 204, a counter unit 205, a protection function processing unit 206, an information collection unit 207, a recording processing unit 208, a non-volatile memory 209, an interface processing unit 210, a display device 211, and an interface 212.

[0064] The magnetic bearing control unit 201 electrically controls the operating state of the magnetic bearings (upper radial electromagnet 104, lower radial electromagnet 105, axial electromagnets 106A and 106B, upper radial sensor 107, lower radial sensor 108 and axial sensor 109) of the rotor shaft 113, and adjusts the radial and axial positions of the rotor shaft 113 as described above.

[0065] The motor drive control unit 202 electrically controls the operation state of the motor 121 and makes the motor 121 rotate at a specified rotation speed.

[0066] The temperature measurement unit 203 is the temperature sensor used in the aforementioned TMS, which measures the temperature at the location where the temperature sensor is located. Specifically, the temperature measurement unit 203 determines the temperature at that location based on the output signal of the temperature sensor.

[0067] The output control unit 204 electrically controls the operating status of TMS output devices such as the heater and the valve (cooling valve) of the water-cooling pipe 149. It switches the heater on / off and the cooling valve on / off to bring the temperature at the temperature sensor location to a specified temperature.

[0068] The counter unit 205 counts, for example, the time from the start of the vacuum pump or the actual time. The counter unit 205 is a timer, real-time clock, or the like that that counts the elapsed time.

[0069] The protection function processing unit 206 obtains the status information of the vacuum pump from the aforementioned magnetic bearing control unit 201, motor drive control unit 202, temperature measurement unit 203, etc., and senses the abnormality when an abnormality occurs in the vacuum pump based on the status information.

[0070] This status information includes the temperatures of various components such as heater temperature, cooling temperature, and rotor blade temperature, as well as the rotational speed (rotation speed) of motor 121, the on / off status of the heater, and the open / closed status of the cooling valve.

[0071] The information collection unit 207 collects specific timing status information from the status information of the vacuum pump body obtained by the protection function processing unit 206.

[0072] Specifically, the information collection unit 207 collects the status information of the vacuum pump body when the control unit (output control unit 204, motor drive control unit 202, etc.) switches the operating state of the internal equipment (TMS output device, motor 121, etc.) configured in the vacuum pump body.

[0073] That is, in this embodiment, the internal device includes a temperature management device (i.e., the TMS output device described above), which includes at least one of a heater and a cooling valve. Furthermore, in this embodiment, the internal device includes a power system device, which includes at least one of a motor 121 and a magnetic bearing.

[0074] Specifically, in this embodiment, the information collection unit 207 collects the state information of the vacuum pump body at the time of vacuum pump startup as the initial value of the state information. Specifically, when the vacuum pump starts, a self-diagnostic process is immediately performed, and the information collection unit 207 collects the state information of the vacuum pump body during this self-diagnostic process as the initial value of the state information. Thus, the number of power-on cycles (i.e., the number of startup cycles) can be determined based on the state information recorded in the non-volatile memory 209.

[0075] Furthermore, in this embodiment, the information collection unit 207 monitors whether the operation state of the internal equipment has been switched using the control unit from the time the vacuum pump is started. Instead of periodically collecting the status information of the vacuum pump body, the information is collected at the time when the operation state of the internal equipment is switched using the control unit.

[0076] The recording processing unit 208 records the status information collected by the information collection unit 207 in the built-in non-volatile memory 209. At this time, timing information indicating the collection timing of the status information is recorded along with the status information. This timing information is obtained by the counter unit 205. The non-volatile memory 209 is a non-volatile memory such as flash memory. Specifically, the recording processing unit 208 (a) records the status information in a storage area of ​​a predetermined size in the non-volatile memory 209, and (b) uses the storage area as a ring buffer to record the status information. That is, a set of timed status information is stored as a dataset in one of the predetermined number of buffer areas in the ring buffer, and after the dataset of status information has been stored in all the predetermined number of buffer areas, the dataset of the oldest status information is overwritten by the dataset of the newest status information.

[0077] The interface processing unit 210 displays the status information of the vacuum pump body obtained by the protection function processing unit 206 using the display device 211. In addition, it reads the status information stored in the non-volatile memory 209 and outputs it to the outside using the interface 212.

[0078] Display device 211 includes indicators such as LEDs and liquid crystal displays to display various information to the user. Interface 212 communicates with external terminal devices via serial communication or other methods that use specified communication standards.

[0079] Next, the operation of the vacuum pump will be explained.

[0080] Figure 6 illustrates an example of the state transition of the turbomolecular pump (vacuum pump) shown in Figure 1. For example, as shown in Figure 6, when the power is turned on, the control device 200 performs a pre-defined self-diagnostic process. When the self-diagnostic process is complete, the magnetic bearing control unit 201 controls the magnetic bearing to keep the vacuum pump in a stationary, suspended state. Then, when the vacuum pump starts operating, the motor drive control unit 202 begins controlling the motor 121, accelerating the motor 121 and putting the vacuum pump into an accelerated operating state. When the rotational speed of the vacuum pump enters the allowable range, the motor drive control unit 202 puts the vacuum pump into a rated operating state. Then, the motor drive control unit 202 appropriately puts the vacuum pump into an accelerated or decelerated operating state to keep the rotational speed of the vacuum pump within the allowable range (i.e., to maintain the rated operating state). At the end of operation, the motor drive control unit 202 puts the vacuum pump into a decelerated operating state, and when no rotation of the motor 121 is detected, the vacuum pump returns to a stationary, suspended state. Furthermore, even when the rotation of the motor is detected when the motor is not in operation, the motor drive control unit 202 causes the vacuum pump to operate in a decelerated state. When the rotation of the motor 121 is not detected, the vacuum pump switches to a stationary suspended state.

[0081] In this way, when the vacuum pump is running, the operating state of the motor 121 is switched and controlled in a manner that maintains the rated operating state. In addition, the heat generated by the motor 121 varies depending on the load of the motor 121 or the gas flow rate, and the ambient temperature also varies. Therefore, as described above, the temperature of the gas flow path is dynamically managed using a TMS.

[0082] The protection function processing unit 206 periodically obtains status information from the magnetic bearing control unit 201, the motor drive control unit 202, the temperature measurement unit 203, etc., to monitor whether any abnormalities occur in the vacuum pump.

[0083] Furthermore, the information collection unit 207 detects the switching timing of the controls of the magnetic bearing control unit 201, the motor drive control unit 202, the output control unit 204, etc. When the switching timing is detected, the status information of the specific item and the time information indicating the switching timing are collected from the protection function processing unit 206 and stored in the non-volatile memory 209 using the recording processing unit 208. Additionally, the time information is provided by the counter unit 205.

[0084] Figures 7 and 8 illustrate the information collection timing of the control device shown in Figure 5. Figure 7 illustrates the information collection timing during vacuum pump startup. Figure 8 illustrates the information collection timing during vacuum pump operation.

[0085] For example, as shown in Figure 7, after the vacuum pump is started, the output control unit 204 turns the heater on and the cooling valve off. As a result, the heater temperature (the value detected by the temperature sensor corresponding to the heater) and the cooling temperature (the value detected by the temperature sensor corresponding to the cooling valve) rise.

[0086] The output control unit 204 controls the heater in the following manner: when the heater temperature exceeds the specified target temperature, the heater is turned off; then, when the heater temperature is lower than the specified target temperature, the heater is turned on, and the heater temperature reaches the specified target temperature. In Figure 7, the heater's operating state switches from the on state to the off state at time points t11, t13, t15, t17, t19, t21, t23, and t25; and the heater's operating state switches from the off state to the on state at time points t12, t14, t16, t18, t20, t22, t24, and t26.

[0087] Furthermore, the output control unit 204 controls the cooling valve in the following manner: when the cooling temperature exceeds the specified target temperature, the cooling valve is opened; subsequently, when the cooling temperature is lower than the specified target temperature, the cooling valve is closed, and the cooling temperature becomes the specified target temperature. In Figure 7, the operating state of the cooling valve switches from closed to open at time points t41, t43, t45, t47, t49, t51, t53, t55, t57, and t59; and the operating state of the cooling valve switches from open to closed at time points t42, t44, t46, t48, t50, t52, t54, t56, t58, and t60.

[0088] The information collection unit 207 monitors whether the operating status of power system equipment such as the TMS output device and motor 121 is switched from the time the vacuum pump is started. Instead of periodically collecting the status information of the vacuum pump body, it collects the status information of the vacuum pump body at regular intervals when the operating status of the internal equipment is switched, and stores it in the non-volatile memory 209 using the recording processing unit 208.

[0089] Therefore, for example, in the case shown in FIG7, the information collection unit 207 collects the status information of the vacuum pump body at timings t11~t26 and t41~t60, and stores it in the non-volatile memory 209 by the recording processing unit 208. Furthermore, for example, as shown in FIG7, the status information is not stored in the non-volatile memory 209 after startup and before the heater temperature or cooling temperature reaches the target temperature.

[0090] Furthermore, after the control of motor 121 is started, if the operating state of the motor changes between accelerated operation, rated operation and decelerated operation, the state information of the vacuum pump body is collected even at the time of the state change and stored in the non-volatile memory 209 by the recording processing unit 208.

[0091] Therefore, for example, in the case shown in FIG8, the information collection unit 207 collects the status information of the vacuum pump body not only during the switching time t71-t76 of the heater's operating state and the switching time t81-t92 of the cooling valve's operating state, but also during the timing of changes in the motor's operating state, and stores this information in the non-volatile memory 209 using the recording processing unit 208. Furthermore, the status information is also collected and recorded when the magnetic bearing's operating state changes between a stationary levitating state and a touch-down state.

[0092] In this way, the status information stored in the non-volatile memory 209 can be read by an external device via the interface 212 and the interface processing unit 210, for example, for analyzing the cause of malfunctions in the vacuum pump.

[0093] As described above, according to the above embodiment, control units 201, 202, and 204 control the operating states of internal devices (motor 121, heater, cooling valve, etc.) disposed in the vacuum pump body. Information collection unit 207 collects state information of the vacuum pump body, and recording processing unit 208 records the state information collected by information collection unit 207 in non-volatile memory 209. Then, information collection unit 207 collects state information of the vacuum pump body at timings when the operating states of the internal devices are switched by control units 201, 202, and 204.

[0094] Therefore, the status information of the vacuum pump is collected at appropriate intervals. Thus, even if the storage area for status information in the non-volatile memory 209 is small, it is easy to perform the cause analysis of vacuum pump malfunctions.

[0095] Furthermore, various modifications and alterations to the above-described embodiments will be apparent to those skilled in the art. Such modifications and alterations can also be made without departing from the spirit and scope of the subject matter and without diminishing the intended advantages. That is, it is intended that such modifications and alterations be included in the claims.

[0096] For example, in the above embodiment, the information collection unit 207 collects all the status information of a specific plurality of items in correspondence with the switching of the operation state of any one of the plurality of internal devices. However, instead, it may collect only the status information of a portion of the items corresponding to the internal devices whose operation state has been switched in correspondence with the switching of the operation state of any one of the plurality of internal devices.

[0097] Furthermore, in the above embodiment, even if the information collection timing (switching of the internal device's operating state) is detected within a specified time from the time point when the state information is stored in the non-volatile memory 209, the storage of the state information in the non-volatile memory 209 may not be performed.

[0098] Industrial availability

[0099] This invention can be applied, for example, to vacuum pumps.

[0100] Explanation of reference numerals in the attached figures

[0101] 100. Turbomolecular pump (an example of a vacuum pump)

[0102] 121 Electric motor (an example of internal equipment)

[0103] 200 control device

[0104] 201 Magnetic Bearing Control Unit (An Example of a Control Unit)

[0105] 202 Motor drive control unit (an example of a control unit)

[0106] 204 Output Control Unit (An Example of a Control Unit)

[0107] 207 Information Collection Department

[0108] 208 Record Processing Department

[0109] 209 Non-volatile memory.

Claims

1. A vacuum pump, characterized in that, The system includes: an internal device disposed within the vacuum pump body; a control unit for controlling the operational state of the internal device; an information collection unit for collecting status information of the vacuum pump body; and a recording and processing unit for recording the status information collected by the information collection unit in a non-volatile memory. The internal device is at least one of a heater and a cooling valve. When the internal device is a heater, the status information includes the heater temperature and the heater's on / off state. When the internal device is a cooling valve, the status information includes the cooling temperature and the cooling valve's open / closed state. The information collection unit monitors the operation of the vacuum pump from the start-up time. Whether the control unit switches the operating state of the internal device, or whether the status information of the vacuum pump body is collected periodically instead of periodically, the status information is collected when the control unit detects that the operating state of the internal device has been switched. If the internal device is a heater, the timing includes the timing when the operating state of the heater switches from the on state to the off state and the timing when the operating state of the heater switches from the off state to the on state. If the internal device is a cooling valve, the timing includes the timing when the operating state of the cooling valve switches from the open state to the closed state and the timing when the operating state of the cooling valve switches from the closed state to the open state.

2. The vacuum pump according to claim 1, characterized in that, The recording processing unit records the state information in a storage area of ​​a predetermined size in the non-volatile memory, and uses the storage area as a ring buffer to record the state information.

3. The vacuum pump according to claim 1 or 2, characterized in that, The information collection unit collects the status information of the vacuum pump body when the vacuum pump is started.

4. A control device for controlling internal equipment disposed in a vacuum pump body, characterized in that, It comprises: a control unit for controlling the operation state of the internal device; an information collection unit for collecting status information of the vacuum pump body; and a recording and processing unit for recording the status information collected by the information collection unit in a non-volatile memory. The internal device is at least one of a heater and a cooling valve. When the internal device is a heater, the status information includes the heater temperature and the heater's on / off state. When the internal device is a cooling valve, the status information includes the cooling temperature and the cooling valve's open / closed state. The information collection unit monitors whether the control unit is used from the start of the vacuum pump. Instead of periodically collecting the status information of the vacuum pump body, the control unit switches the operating state of the internal device. Instead, it collects the status information when it detects that the operating state of the internal device has been switched by the control unit. When the internal device is a heater, the timing includes the timing of the heater's operating state switching from an on state to an off state and the timing of the heater's operating state switching from an off state to an on state. When the internal device is a cooling valve, the timing includes the timing of the cooling valve's operating state switching from an open state to a closed state and the timing of the cooling valve's operating state switching from a closed state to an open state.

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