JP2019132508A - Fan filter unit - Google Patents

Abstract

To provide a fan filter unit capable of smoothly performing a periodic inspection and an advance planning of the inspection by easily grasping a period of abnormal sound generation in a motor due to electric corrosion, which is the most likely cause of failure.SOLUTION: A resin-molded motor 2 of a fan filter unit 5 including a fan 1 outside of a device, a motor 2, a filter 3 and a control unit 4 has a shaft voltage detection unit 16 for measuring a voltage between an outer shell of a bearing 12 and an outer shell of a shaft 13, and a shaft voltage determination unit 18, and the fan filter unit can easily grasp a period of abnormal sound generation in the motor due to electric corrosion, which is the most likely cause of failure.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fan filter unit that is installed in a place that requires a clean space, such as a manufacturing apparatus that manufactures semiconductor devices, liquid crystals, and the like that are mainly installed in a clean room, or a clean booth.

  Conventionally, a fan filter unit (FFU) installed in this type of semiconductor manufacturing factory has been provided with a fan motor that blows air outside the factory into the factory and a filter that improves the cleanliness of the air inside the factory.

  In this type of factory, it is essential to operate the fan filter unit continuously because production is not stopped.

  Therefore, a plurality of fan filter units are grouped into one group, and operation and periodic inspection are performed for each group to ensure a predetermined air cleanliness.

  Since smooth periodic inspections and advance planning lead to improved production efficiency, the current of each part of the fan motor, the number of revolutions, and the pressure of the air passage are used to obtain predictive information on the life of the installed fan motor. Measurements of fan motor vibration, installation environment temperature, etc. were carried out every day.

  And by accumulating and memorizing the data at the time of normal driving | operation, compared with the time of abnormality, the difference was found and it was used as the prediction information regarding a lifetime.

JP 2003-23792 A

  Such a conventional fan filter unit obtains information related to the life of the fan motor from measurement data such as the current of each part of the fan motor, the number of revolutions, the pressure of the air passage, and the temperature of the installation environment, but estimates the motor life. There were multiple causes of failure, and the process leading to the failure was complicated, so the accuracy was poor.

  Therefore, the present invention solves the above-mentioned problems, and easily grasps the generation time of abnormal noise of a motor due to electric corrosion, which is a high percentage of failure factors, and facilitates periodic inspection and advance planning. An object is to provide a fan filter unit that can be performed.

  In order to achieve this object, a fan filter unit according to the present invention includes a fan that blows air outside the apparatus into the apparatus, a motor that drives the fan, a filter that maintains air cleanliness, A fan filter unit including a control unit for controlling a motor, wherein the motor is resin-molded, measures a voltage between a bearing outline of the motor and the shaft outline, and determines the bearing outline and the shaft outline. A shaft voltage detection unit that outputs a signal corresponding to a voltage between the motors to the control unit via an input / output terminal of the motor is provided, thereby achieving an intended purpose. it can.

  ADVANTAGE OF THE INVENTION According to this invention, the fan filter unit from which the effect of grasping | ascertaining the lifetime of a motor easily can be provided.

Configuration diagram of Embodiment 1 of the present invention Block diagram of Embodiment 1 of the present invention Block diagram of Embodiment 1 of the present invention

  The fan filter unit according to claim 1 of the present invention includes a fan that blows air outside the apparatus into the apparatus, a motor that drives the fan, a filter that maintains air cleanliness, and a control unit that controls the motor. The motor is resin-molded, and measures the voltage between the bearing outline and the shaft outline of the motor, and outputs a signal corresponding to the voltage between the bearing outline and the shaft outline. A shaft voltage detector that outputs to the controller via an input / output terminal of the motor is provided.

  As a result, the shaft voltage detector measures the voltage between the bearing outline and the shaft outline of the motor, and outputs a signal corresponding to the voltage between the bearing outline and the shaft outline to the controller via the input / output terminal. Knowing the motor life as the frequency of electric corrosion corresponding to the voltage between the bearing shell and the shaft shell in advance makes it possible to determine the life in the control unit, so the proportion of failure factors It is possible to easily grasp the generation time of abnormal noise of the motor due to high electric corrosion, and to perform periodic inspections and advance planning smoothly.

  According to a second aspect of the present invention, the fan filter unit includes an axial voltage determination unit, a central processing unit, and an abnormal alarm output unit in the control unit, and the axial voltage determination unit compares the voltage measured by the axial voltage detection unit. The shaft voltage determination unit outputs a result of comparing the threshold voltage with the voltage between the bearing outline and the shaft outline to the central processing unit, and receives the signal from the central processing unit to detect the abnormality. The notification output unit issues an abnormality.

  As a result, the shaft voltage detection unit measures the voltage between the bearing outline of the motor and the shaft outline, and the shaft voltage determination unit of the control unit compares the signal determined by the threshold for determining the value for the measured voltage with the central processing unit. The abnormality report output unit that outputs to the central processing unit and receives the signal from the central processing unit notifies the abnormality report, so that it is possible to inform the replacement time, so that the maintenance schedule can be adjusted.

  Further, in the fan filter unit according to claim 3, the threshold for comparing the voltage measured by the shaft voltage detector is a threshold according to the remaining life of the motor estimated in advance, and the controller includes A setting unit for setting the threshold value via an operation switch is provided.

  As a result, the setting unit of the control unit inputs the threshold according to the customer's request, and notifies the customer that an abnormal report has been issued. .

  Further, the setting unit of the fan filter unit according to claim 4 can set the threshold value stepwise.

As a result, the setting unit can subdivide and set the threshold value based on the input information from the operation switch, notify the abnormal report step by step, and inform the customer of the replacement time with improved accuracy.
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1 to FIG. 3, the fan filter unit in the present embodiment will be described with reference to the block diagram and block diagram.

  As shown in FIG. 1, the fan filter unit 5 includes a fan 1 that blows air outside the semiconductor manufacturing apparatus into the apparatus, a motor 2 that drives the fan 1, a filter 3 that maintains air cleanliness, and a motor 2. The control part 4 which controls the rotation speed of is provided. The fan filter unit 5 is a device that is required to operate 24 hours a day, 365 days a year, and the stop of the fan filter unit 5 is a device that is only scheduled for several maintenance days a year.

  Also, to improve the productivity of the semiconductor manufacturing apparatus, it is always necessary to maintain the air cleanliness. The decrease in the air cleanliness due to the failure of the fan filter unit 5 is caused by, for example, discarding a large number of wafers in the semiconductor manufacturing apparatus. Therefore, each company monitors the operation of the fan filter unit 5 in the manufacturing process.

  Therefore, when the fan filter unit 5 finds an abnormality, the abnormality is output from the abnormality reporting output unit 7 in the control unit 4 to the abnormality reporting input unit 8 in the semiconductor manufacturing apparatus control unit 6 via the abnormality output line 9. An alarm signal is issued.

  Thereby, the cause is investigated on the semiconductor manufacturing apparatus side and the abnormality is solved.

  As shown in FIG. 2, the motor 2 mounted in the fan filter unit 5 is resin-molded.

  The interior of the motor 2 includes a stator 10 having a stator winding and a rotor 11 that rotates the fan 1 with a permanent magnet.

  Further, the rotor 11 is penetrated by a shaft 13, and is sandwiched between bearings 12 at both ends of the rotor 11.

  Moreover, the control part 4 becomes a structure which the rotor 11 rotates by the designated rotation speed to a designated direction by carrying out energization control to the stator 10. FIG.

  In the case of a molded motor, the shaft 13 passing through the rotor 11 is electrically insulated from the ground (ground).

  The bearing 12 which is a bearing of the rotor 11 includes a ball bearing (not shown) inside, and has a structure in which the outer shell of the shaft 13 and the inner shell of the bearing 12 are brought into contact with each other.

  Since the outer shell of the bearing 12 is insulated by the grease of the ball bearing, the outer shell of the shaft 13 (the inner shell of the bearing 12) and the outer shell of the bearing 12 are kept insulated.

  The outer shell of the bearing 12 is also electrically insulated from the ground (ground).

  Therefore, the ball bearing between the outer shell of the shaft 13 of the molded motor and the outer shell of the bearing 12 has a current flowing on the surface of the ball bearing due to the influence of electromagnetic noise when a device that generates harmonics is installed nearby. In some cases, discharge may cause damage to the spherical surface.

  This phenomenon is galvanic corrosion, which is likely to occur in a molded motor, generates abnormal noise, vibration, and the like, and has been raised as one of the causes of life reduction.

  Further, since the outer shell of the bearing 12 and the outer shell of the shaft 13 are at a potential that is electrically insulated from the ground, as a method of monitoring electrolytic corrosion, the outer shell of the bearing 12 is detected on the outer shell of the bearing 12. The shaft outer shell detection means 15 is provided on the outer periphery of the means 14 and the shaft 13, and the shaft voltage detection section 16 that can detect the potential difference between each other is provided.

  The bearing outer shell detecting means 14 and the shaft outer shell detecting means 15 do not need a special operation or operation for detecting a potential difference by always contacting the outer shell portion.

  Then, at a predetermined specific timing, the potential is measured simultaneously by the bearing outer shell detecting means 14 and the shaft outer shell detecting means 15 to detect a potential difference between both ends of the bearing 12 and the shaft 13.

  For example, a differential method is generally used as a potential difference detection method.

  The shaft voltage detection unit 16 outputs the detected voltage signal to the control unit 4 via the input / output terminal 17 of the motor 2.

  The shaft voltage discriminating unit 18 on the control unit 4 side sets a threshold value and compares it with the voltage signal detected by the shaft voltage detecting unit 16, so that there is a risk of electric corrosion from the degree of generation of the shaft voltage based on the detected voltage signal. Judgment can be made. For example, the shaft voltage discriminating unit 18 uses a comparator of an electronic component, forms a circuit configuration in which a reference voltage is set by a voltage dividing resistor to set a threshold value, and a comparison judgment is made by an input signal from the shaft voltage detecting unit 16. Good.

  Further, as the threshold setting, for example, when the potential difference between both ends is 5 V or more, it is determined that there is a possibility of electric corrosion, and the shaft voltage determination unit 18 immediately outputs to the central processing unit 19 the source of the abnormal report. Output a signal.

  Then, the central processing unit 19 issues an abnormal output signal to the abnormal notification output unit 7 in accordance with the output signal of the shaft voltage determination unit 18. Thereby, the semiconductor manufacturing apparatus control part 6 can grasp | ascertain the lifetime of a motor easily.

  As shown in FIG. 3, the threshold for comparing and determining the voltage detected by the shaft voltage detection unit 16 can be set according to the customer's request at which timing the alarm is issued with respect to the remaining estimated motor life. It is a threshold value.

  The control unit 4 includes a setting unit 21 that sets a threshold value via the operation switch 20. As an example, the operation switch 20 is configured to include a display unit and a switch unit, and can be set by pressing an UP switch and a DOWN switch of the switch unit while viewing the display unit.

  Then, setting data is input to the setting unit 21 via the operation switch 20.

  In addition, when the threshold is set to issue an abnormal output at 5.0 V, the setting unit 21 can change the setting to 4.0 V with the threshold lowered.

  The threshold value changed by the customer in the setting unit 21 is stored in the threshold value storage means 22 in the central processing unit 19.

  The stored threshold value data is obtained by comparing the threshold data from the threshold value storage means 22 of the central processing unit 19 every time the shaft voltage discriminating unit 18 compares the detection data from the shaft voltage detection unit 16, and the comparison is made. Anomaly output is issued upon request.

  Moreover, the setting part 21 is set as the setting which can alert | report the abnormal output signal of the central processing unit 19 in steps by changing the setting method of a threshold value. As an example, if an abnormal output has been issued at 5.0 V or higher, the abnormal output can be output in stages, so that a mild abnormal output at 4.0 V or higher (motor stop prediction after 60 days) It is possible to set an abnormal output such as a moderate abnormality report (predicting motor stop after 30 days) at 4.5V or more, and a severe abnormality report (predicting motor stop immediately) at 5.0V or more.

  With the above configuration, if the shaft voltage detection unit 16 measures the voltage between the outer surface of the bearing 12 and the outer surface of the shaft 13 of the motor 2 to grasp the life of the motor 2 corresponding to the voltage, the control unit 4 It is possible to determine the life in

  Further, the shaft voltage detector 16 measures the voltage between the outer surface of the bearing 12 of the motor 2 and the outer surface of the shaft 13, and the shaft voltage determination unit 18 notifies an abnormal report by a threshold value for determining a value for the measured voltage. By doing so, it is possible to tell the replacement time, so it is possible to adjust the maintenance schedule.

  In addition, the setting unit 21 of the control unit 4 inputs the threshold value according to the customer's request by an input unit that can set the threshold value, and notifies the abnormal report according to the customer's request, so that the replacement time becomes clear. Maintenance schedule can be easily adjusted.

  In addition, the setting unit 21 of the control unit 4 can divide the threshold value and notify the abnormal report stepwise by an input means that can set the threshold value in a stepwise manner. You can tell the replacement time.

  The fan filter unit of the present invention is installed in a place where maintenance of air cleanliness is required for continuous operation for 24 hours, such as a manufacturing apparatus for manufacturing a semiconductor device or liquid crystal installed in a clean room, or a clean booth. Can be provided where you can.

1 Fan 2 Motor 3 Filter 4 Control Unit 5 Fan Filter Unit (FFU)
6 Semiconductor Manufacturing Device Control Unit 7 Abnormal Report Output Unit 8 Abnormal Report Input Unit 9 Abnormal Output Line 10 Stator 11 Rotor 12 Bearing 13 Shaft 14 Bearing Outer Shell Detection Unit 15 Shaft Outer Shell Detection Unit 16 Axis Voltage Detection Unit 17 Input / Output Terminal 18 Axis voltage discrimination unit 19 Central processing unit 20 Operation switch 21 Setting unit 22 Threshold storage means

Claims (4)

A fan filter unit comprising: the fan that blows air outside the apparatus into the apparatus; a motor that drives the fan; a filter that maintains air cleanliness; and a control unit that controls the motor;
The motor is resin-molded, measures a voltage between a bearing outline and a shaft outline of the motor, and sends a signal corresponding to a voltage between the bearing outline and the shaft outline via an input / output terminal of the motor. A fan filter unit comprising a shaft voltage detector for outputting to the controller. The control unit is provided with an axis voltage discriminating unit, a central processing unit, and an abnormal alarm output unit, and the axis voltage discriminating unit is provided with a threshold value to be compared with the voltage measured by the axis voltage detecting unit, A result of comparing the voltage between the bearing outline and the shaft outline and the threshold value is output to the central processing unit, and the abnormality notification output unit reports an abnormality in response to a signal from the central processing unit. The fan filter unit according to claim 1. The threshold for comparing the voltage measured by the shaft voltage detector is a threshold according to the remaining life of the motor estimated in advance,
The fan filter unit according to claim 2, wherein the control unit includes a setting unit that sets the threshold value via an operation switch. The fan filter unit according to claim 3, wherein the setting unit can set the threshold value stepwise.