Monitoring mechanism and vacuum pump

Abstract

The utility model relates to the technical field of monitoring, and provides a monitoring mechanism and a vacuum pump. The monitoring mechanism comprises a displacement sensor and a controller. The displacement sensor is used for acquiring axial displacement parameters of the rotating shaft. The controller is electrically connected with the displacement sensor and used for receiving the axial displacement parameters. And a displacement alarm threshold value is set in the controller. And the controller gives an alarm when the axial displacement parameter is greater than or equal to a displacement alarm threshold value. Therefore, the axial clearance of the rotating shaft of the vacuum pump can be monitored in real time, and the technical problem that the vacuum pump is stuck due to the fact that the axial clearance of the rotating shaft of the vacuum pump is too small is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of monitoring, in particular to a monitoring mechanism and a vacuum pump. Background Art

[0002] In the relevant technology, vacuum pumps are widely used in defense science and technology, steel industry, coating, microelectronics information, semiconductor, biomedicine, chemical industry, food, environmental protection and other industries. The axial clearance of the rotating shaft in the vacuum pump is a necessary condition for its normal operation and plays a vital role. If the axial clearance of the rotating shaft is too large, the efficiency of the vacuum pump will be reduced. If the axial clearance of the rotating shaft is too small, it will easily cause the vacuum pump to get stuck. When the vacuum pump continues to work, the internal rotating shaft will expand due to heat, causing the axial clearance to decrease, resulting in the risk of the vacuum pump getting stuck. Utility Model Content

[0003] The embodiments of the utility model provide a monitoring mechanism and a vacuum pump, which can improve the technical problem of the vacuum pump being stuck due to the small axial clearance of the rotating shaft of the vacuum pump.

[0004] In a first aspect, an embodiment of the utility model provides a monitoring mechanism for monitoring the axial displacement of a rotating shaft of a vacuum pump, comprising:

[0005] A displacement sensor, used to obtain the axial displacement parameters of the rotating shaft;

[0006] The controller is electrically connected to the displacement sensor and is used to receive the axial displacement parameter. A displacement alarm threshold is set in the controller. The controller generates an alarm in response to the axial displacement parameter being greater than or equal to the displacement alarm threshold.

[0007] In some embodiments, the controller includes:

[0008] A signal receiving module, electrically connected to the displacement sensor, and configured to receive the axial displacement parameter;

[0009] a comparison module, electrically connected to the signal receiving module, and configured to compare the axial displacement parameter with the displacement alarm threshold, wherein the comparison module outputs an alarm signal based on the axial displacement parameter being greater than or equal to the displacement alarm threshold;

[0010] The alarm module is electrically connected to the comparison module and is used to receive the alarm signal and generate an alarm.

[0011] In some embodiments, the monitoring mechanism further comprises:

[0012] A temperature sensor, used to obtain temperature parameters of the space where the rotating shaft is located;

[0013] The controller is set with normal temperature parameters, and the controller also includes:

[0014] The first calculation module is electrically connected to the temperature sensor, and is used to obtain a temperature difference parameter between the temperature parameter and the normal temperature parameter.

[0015] In some embodiments, the controller further comprises:

[0016] A storage module is electrically connected to the comparison module and the first calculation module, and the displacement alarm threshold and the normal temperature parameter are both stored in the storage module.

[0017] In some embodiments, the controller further comprises:

[0018] A signal processing module is electrically connected to the signal receiving module and is used to convert the axial displacement parameter into a first digital signal. The signal processing module is also electrically connected to the temperature sensor and is used to convert the temperature parameter into a second digital signal. The comparison module is electrically connected to the signal processing module and is used to compare the first digital signal with the displacement alarm threshold. The first calculation module is electrically connected to the signal processing module to obtain the temperature difference parameter based on the second digital signal and the normal temperature parameter.

[0019] In some embodiments, the controller further comprises:

[0020] The display module is electrically connected to the signal processing module and is used to receive the first digital signal and the second digital signal to digitally display the axial displacement parameter and the temperature parameter of the space where the rotating shaft is located.

[0021] In a second aspect, an embodiment of the utility model provides a vacuum pump, comprising:

[0022] Pump body assembly;

[0023] Such as the aforementioned monitoring agencies;

[0024] Wherein, the rotating shaft is installed in the pump body assembly, and the displacement sensor is arranged on the vacuum pump near the end of the rotating shaft.

[0025] In some embodiments, the vacuum pump further comprises:

[0026] The first bearing plate and the second bearing plate are arranged on opposite sides of the pump body assembly, wherein two ends of the rotating shaft are rotatably connected to the first bearing plate and the second bearing plate respectively.

[0027] In some embodiments, the vacuum pump further comprises:

[0028] The end cover is connected to the first bearing plate or the second bearing plate. The end cover is configured with a measuring hole. The measuring hole is coaxially arranged with the rotating shaft. The displacement sensor is installed in the measuring hole.

[0029] In some embodiments, the rotating shafts are arranged in at least two forms, at least two of which are arranged at intervals along their radial directions, at least two measuring holes are arranged at intervals on the end cover, a displacement sensor is installed in each of the measuring holes, and each of the displacement sensors respectively obtains an axial displacement parameter of the rotating shaft.

[0030] In some embodiments, the vacuum pump further comprises:

[0031] Motor components;

[0032] A gear box assembly, one side of which is connected to the motor assembly, and the other side of which is connected to the pump assembly;

[0033] Wherein, the output shaft of the motor assembly is transmission-connected to the first end of the gear box assembly, and the rotating shaft is transmission-connected to the second end of the gear box assembly.

[0034] Beneficial effects of the embodiments of the utility model:

[0035] In an embodiment of the utility model, the axial displacement parameter of the rotating shaft is obtained by a displacement sensor, and the controller determines whether to alarm based on the comparison result of the axial displacement parameter and the displacement alarm threshold. When the axial displacement parameter is less than the displacement alarm threshold, no alarm is given. At this time, the vacuum pump will not get stuck, and the vacuum pump can continue to work normally. When the axial displacement parameter is greater than or equal to the displacement alarm threshold, an alarm is given. At this time, the axial displacement of the rotating shaft is large, which will cause the axial clearance of the rotating shaft to be too small, and the vacuum pump is at risk of getting stuck. The operator can detect the vacuum pump based on the alarm information, thereby adjusting the axial clearance of the rotating shaft to prevent the vacuum pump from getting stuck. Thus, the axial clearance of the rotating shaft of the vacuum pump can be monitored in real time to improve the technical problem of the vacuum pump getting stuck due to the axial clearance of the rotating shaft of the vacuum pump being too small. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 It is a schematic diagram of the structure of a vacuum pump provided in an embodiment of the utility model.

[0038] Figure 2It is a structural schematic diagram of the installation of the displacement sensor provided in the embodiment of the utility model.

[0039] Figure 3 It is a cross-sectional view of a rotating shaft and an end cover provided in an embodiment of the utility model.

[0040] Figure 4 It is a structural schematic diagram of a monitoring mechanism provided in an embodiment of the utility model.

[0041] Reference numerals:

[0042] 10-displacement sensor, 20-controller, 210-signal receiving module, 220-comparison module, 230-alarm module, 240-first calculation module, 250-second calculation module, 260-storage module, 270-signal processing module, 280-display module, 30-temperature sensor, 40-rotating shaft, 510-pump body assembly, 520-first bearing plate, 530-second bearing plate, 540-end cover, 550-measuring hole, 560-motor assembly, 570-gear box assembly. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the utility model, and are not used to limit the utility model. In the utility model, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0044] Specifically, Figures 1 to 4 As shown, an embodiment of the present application provides a monitoring mechanism. The monitoring mechanism is used to monitor the axial displacement of the rotating shaft 40 of the vacuum pump. The monitoring mechanism includes a displacement sensor 10 and a controller 20. The displacement sensor 10 is used to obtain the axial displacement parameters of the rotating shaft 40. The controller 20 is electrically connected to the displacement sensor 10, and is used to receive the axial displacement parameters. A displacement alarm threshold is set in the controller 20. The controller 20 issues an alarm in response to the axial displacement parameter being greater than or equal to the displacement alarm threshold.

[0045] It is understandable that the axial displacement parameter of the rotating shaft 40 is obtained by the displacement sensor 10, and the controller 20 determines whether to alarm based on the comparison result of the axial displacement parameter and the displacement alarm threshold. When the axial displacement parameter is less than the displacement alarm threshold, no alarm is given. At this time, the vacuum pump will not get stuck, and the vacuum pump can continue to work normally. When the axial displacement parameter is greater than or equal to the displacement alarm threshold, an alarm is given. At this time, the axial displacement of the rotating shaft 40 is large, which will cause the axial clearance of the rotating shaft 40 to be too small, and the vacuum pump is at risk of getting stuck. The operator can detect the vacuum pump based on the alarm information, thereby adjusting the axial clearance of the rotating shaft 40 to prevent the vacuum pump from getting stuck. Thus, the axial clearance of the rotating shaft 40 of the vacuum pump can be monitored in real time to improve the technical problem of the vacuum pump getting stuck due to the small axial clearance of the rotating shaft 40 of the vacuum pump.

[0046] In some embodiments, the displacement sensor 10 may be one or more of an inductive displacement sensor, a capacitive displacement sensor, a photoelectric displacement sensor, an ultrasonic displacement sensor, a Hall displacement sensor, and a magnetostrictive displacement sensor. The axial displacement of the rotating shaft 40 is the axial displacement of the rotating shaft 40 relative to the stator around the area where the rotating shaft 40 is located.

[0047] The controller 20, as a central control unit, can receive the axial displacement parameters monitored by the displacement sensor 10. The controller 20 can be connected to the displacement sensor 10 by wireless signals. For example, the controller 20 and the displacement sensor 10 are connected via WIFI or Bluetooth. Alternatively, the controller 20 can also be connected to the displacement sensor 10 by wired signals. For example, the controller 20 and the displacement sensor 10 are connected via a data cable.

[0048] The rotating shaft 40 can be displaced in the direction of the displacement sensor 10, and at this time, the axial displacement parameter obtained by the displacement sensor 10 is a positive value. The rotating shaft 40 can also be displaced in the direction away from the displacement sensor 10, and at this time, the axial displacement parameter obtained by the displacement sensor 10 is a negative value. Generally speaking, the rotating shaft 40 will generate heat due to continuous operation, causing a certain axial expansion of the rotating shaft 40. For the end of the rotating shaft 40 facing the displacement sensor 10, the end of the rotating shaft 40 is displaced in the direction close to the displacement sensor 10. The greater the displacement, the smaller the axial clearance of the rotating shaft 40 will be, which may cause the vacuum pump to become stuck.

[0049] In some embodiments, the displacement alarm threshold is less than the wear threshold of the shaft. It is understandable that when an alarm is issued in response to the axial displacement parameter being greater than or equal to the displacement alarm threshold, the shaft is in an unworn state. Then the alarm information can be used as a risk warning alarm to remind the staff of the risk of the vacuum pump being stuck later.

[0050] In some embodiments, the displacement alarm threshold is equal to the wear threshold of the shaft. It is understandable that when an alarm is issued in response to the axial displacement parameter being greater than or equal to the displacement alarm threshold, the shaft has been worn. The alarm information can be used as a fault prompt alarm to remind the staff to stop the machine for maintenance.

[0051] In some embodiments, the displacement alarm threshold value set in the controller 20 can be 0.1 mm, 0.5 mm, 1 mm, or any value between the two. For example, the displacement alarm threshold value is set to 0.5 mm, and when the value of the axial displacement parameter obtained is less than 0.5 mm, no alarm is given. At this time, the vacuum pump will not get stuck, and the vacuum pump can continue to work normally. When the value of the axial displacement parameter obtained is greater than or equal to 0.5 mm, an alarm is given.

[0052] like Figure 4 As shown, in some embodiments, the controller 20 includes a signal receiving module 210, a comparison module 220 and an alarm module 230. The signal receiving module 210 is electrically connected to the displacement sensor 10, and is used to receive the axial displacement parameter. The comparison module 220 is electrically connected to the signal receiving module 210, and is used to compare the axial displacement parameter with the displacement alarm threshold. The comparison module 220 outputs an alarm signal based on the axial displacement parameter being greater than or equal to the displacement alarm threshold. The alarm module 230 is electrically connected to the comparison module 220, and is used to receive the alarm signal and issue an alarm.

[0053] It is understandable that after receiving the axial displacement parameter, the signal receiving module 210 can send the axial displacement parameter to the comparison module 220. The comparison module 220 compares the comparison module 220 with the set displacement alarm threshold, and outputs an alarm signal to the alarm unit based on the comparison result. The alarm unit responds to the alarm signal and can alarm to prompt the operator to detect the vacuum pump.

[0054] The signal receiving module 210 can be set as a signal receiver. The signal receiving module 210 can receive the axial displacement parameter monitored by the displacement sensor 10. Among them, the signal receiving module 210 can be connected to the displacement sensor 10 by wireless signal. For example, the signal receiving module 210 is connected to the displacement sensor 10 via WIFI or Bluetooth. Alternatively, the signal receiving module 210 can also be connected to the displacement sensor 10 by wired signal. For example, the signal receiving module 210 is connected to the displacement sensor 10 via a data cable.

[0055] The comparison module 220 can be set as a comparator or a comparison circuit, which is mainly used for size comparison. After receiving the axial displacement parameter, the comparison module 220 compares the value with the preset displacement alarm threshold. If the axial displacement parameter is less than the displacement alarm threshold, the comparison module 220 does not send an alarm signal to the alarm module 230. If the axial displacement parameter is greater than or equal to the displacement alarm threshold, the comparison module 220 sends an alarm signal to the alarm module 230.

[0056] The alarm module 230 may be configured as an alarm, such as a buzzer alarm, a strobe alarm light, an audible and visual alarm, etc. The alarm module 230 may generate an alarm sound and / or an alarm light based on the alarm signal to prompt the operator to detect the vacuum pump.

[0057] like Figure 1 and Figure 4 As shown, in some embodiments, the monitoring mechanism further includes a temperature sensor 30. The temperature sensor 30 is used to obtain the temperature parameter of the space where the rotating shaft 40 is located. A normal temperature parameter is set in the controller 20. The controller 20 further includes a first calculation module 240. The first calculation module 240 is electrically connected to the temperature sensor 30. The first calculation module 240 is used to obtain a temperature difference parameter between the temperature parameter and the normal temperature parameter.

[0058] It is understandable that by obtaining the temperature parameters of the space where the shaft 40 is located and performing difference calculation with the set normal temperature parameters, the temperature difference parameters of the shaft 40 can be obtained. Based on the phenomenon of thermal expansion and contraction, it can be known that the shaft 40 will expand after heating. The acquisition of the temperature difference parameters facilitates the subsequent calculation of the axial clearance of each stage of the rotor.

[0059] The rotating shaft 40 is usually arranged in the pump assembly 510 of the vacuum pump, and the temperature sensor 30 can obtain the temperature inside the pump assembly 510 to reflect the temperature parameters of the space where the rotating shaft 40 is located. Therefore, the temperature sensor 30 is usually directly installed in the cavity of the pump assembly 510.

[0060] In some embodiments, the temperature sensor 30 may be one or more of a thermocouple temperature sensor, a thermistor temperature sensor, and an infrared radiation temperature sensor.

[0061] The normal temperature parameter may be a room temperature parameter. The normal temperature parameter may be obtained by an external temperature probe and then input into the controller 20 to form a preset normal temperature parameter. The normal temperature parameter may also be directly set, for example, the normal temperature parameter may be set to 25 degrees Celsius.

[0062] The first calculation module 240 can be set as a difference calculator. It obtains the temperature difference parameter based on the input temperature parameter and the normal temperature parameter. The calculation formula of the first calculation module 240 is: temperature parameter = temperature parameter - normal temperature parameter.

[0063] In some embodiments, preset parameters are set in the controller 20. The controller 20 also includes a second calculation module 250. The second calculation module 250 is electrically connected to the signal receiving module 210 and the first calculation module 240, and is used to receive axial displacement parameters and temperature difference parameters. The rotating shaft 40 includes at least two rotors arranged in sequence along its axial direction. The rotor is defined as the i-th stage rotor based on its relative position with the displacement sensor 10. Wherein, i is an integer greater than or equal to 1, and the rotor close to the displacement sensor 10 is the first stage rotor. Each stage of the rotor corresponds to a stator. A partition is provided between each adjacent two stages of the stator. The gap between each stage of the rotor and the corresponding partition is defined as the axial gap parameter of the rotor. The displacement sensor 10 is used to obtain the axial displacement parameter of the first stage rotor close to one end of the displacement sensor 10. The second calculation module 250 obtains the axial gap parameter of each stage of the rotor based on the axial displacement parameter, the temperature difference parameter and the preset parameter.

[0064] It is understandable that the second calculation module 250 can receive the axial displacement parameter and the temperature parameter. The second calculation module 250 is set with a calculation logic, which can calculate the axial clearance parameter of each stage of the rotor based on the preset parameter, the axial displacement parameter and the temperature parameter. Thus, real-time monitoring can be performed for each stage of the rotor to prevent the axial clearance of the rotor far away from the displacement sensor 10 from being too small, thereby causing the vacuum pump to get stuck.

[0065] The rotating shaft 40 in the pump body assembly 510 of the vacuum pump includes a plurality of rotors arranged in sequence along the axial direction. Since the number of rotors is set to at least two, the number of stators is also set to at least two. At least two stators can be defined as the i-th stage stators based on the corresponding rotors. The adjacent two-stage stators are separated by a partition. Among them, the partition is a circular partition so that the rotating shaft can pass through each partition. The axial clearance parameter of the rotor is defined as the gap between each stage of the rotor and the corresponding partition. It can be understood that the rotor needs to form a gap with the partition to prevent the partition from interfering with the rotation of the rotor. When the rotor abuts against the partition, it may cause pump jamming and other phenomena.

[0066] When the vacuum pump is working continuously, each rotor may be deformed due to the increase of ambient temperature. Then the axial clearance between each rotor and the corresponding stator may change. If the change value of the axial clearance between the corresponding rotor and the stator is too large, the axial clearance between the rotor and the stator may be too small, resulting in the vacuum pump jam. Therefore, the second calculation module 250 can directly obtain the axial clearance parameters of each stage of the rotor relative to each stage of the stator, so as to monitor the rotor of each stage.

[0067] For example, the rotating shaft 40 includes three rotors arranged in sequence along the axial direction thereof. In the direction away from the displacement sensor 10, the three rotors are the first-stage rotor, the second-stage rotor and the third-stage rotor in sequence. The displacement sensor 10 is used to obtain the axial displacement parameter of the first-stage rotor close to one end of the displacement sensor 10. The second calculation module 250 can obtain the first-stage axial clearance parameter of the first-stage rotor, the second-stage axial clearance parameter of the second-stage rotor, and the third-stage axial clearance parameter of the third-stage rotor based on the axial displacement parameter, the temperature difference parameter and the preset parameter.

[0068] The second calculation module 250 can be configured as a single chip microcomputer programmed with a corresponding calculation program. The calculation program can be:

[0069]

[0070] Where i is the position of the rotor. j is the end position parameter of the rotor. The front end of the rotor corresponds to j = 1. The rear end of the rotor corresponds to j = -1. ij is the axial clearance parameter between the jth end of the i-th stage rotor and the corresponding partition. 装ij is the preset assembly clearance parameter between the jth end of the i-th stage rotor and the corresponding partition. 位 is the axial displacement parameter measured by the displacement sensor 10. i is the thermal expansion coefficient of the i-th stage rotor. i is the initial axial dimension parameter of the i-th stage rotor. ΔT is the temperature difference parameter between the temperature parameter of the space where the rotating shaft 40 is located and the set normal temperature parameter.

[0071] In some embodiments, the preset parameters include preset assembly clearance parameters of each stage of the rotor, end position parameters of each stage of the rotor, initial axial dimension parameters of each stage of the rotor, and thermal expansion coefficient of each stage of the rotor.

[0072] For example, the second calculation module 250 can calculate the i-th axial clearance parameter between the i-th rotor and the corresponding partition based on the axial displacement parameter, the temperature difference parameter, the preset assembly clearance parameter of each stage of the rotor, the end position parameter of each stage of the rotor, the initial axial size parameter of each stage of the rotor, and the thermal expansion coefficient of each stage of the rotor.

[0073] It is understandable that after each stage of the rotor is assembled in the vacuum pump, there will be a corresponding assembly gap value, which is used as a preset assembly gap parameter of the corresponding rotor.

[0074] The initial axial dimension parameter of each stage of the rotor is the initial length of the rotor. For example, the initial axial dimension parameter of the second stage rotor is the initial length of the second stage rotor.

[0075] The thermal expansion coefficient of each stage of the rotor is related to the material of the rotor of that stage. When each stage of the rotor of the rotating shaft 40 is made of the same material, the thermal expansion coefficient of each stage of the rotor is the same. When each stage of the rotor of the rotating shaft 40 is made of different materials, the thermal expansion coefficient of each stage of the rotor is different.

[0076] In some embodiments, the end position parameters of the rotor include a front end parameter and a rear end parameter, the front end parameter is 1, and the rear end parameter is -1, wherein the front end is the end of the rotor close to the displacement sensor 10, and the rear end is the end of the rotor away from the displacement sensor 10.

[0077] It is understandable that the rotor has two opposite ends, which are defined as the front end and the rear end. When the rotor expands due to heat, the front end and the rear end of the rotor will both be displaced, causing the axial clearance value of the front end of the rotor and the axial clearance value of the rear end of the rotor to change. Therefore, based on the introduction of the end position parameters of the rotor, the axial clearance parameters of the front end and the axial clearance parameters of the rear end of each stage of the rotor can be calculated.

[0078] For example, the rotating shaft 40 includes three rotors arranged in sequence along the axial direction thereof. In the direction away from the displacement sensor 10, the three rotors are the first-stage rotor, the second-stage rotor and the third-stage rotor in sequence. The displacement sensor 10 is used to obtain the axial displacement parameter of the first-stage rotor near one end of the displacement sensor 10. The second calculation module 250 can obtain the first-stage front end axial clearance parameter and the first-stage rear end axial clearance parameter of the first-stage rotor, obtain the second-stage front end axial clearance parameter and the second-stage rear end axial clearance parameter of the second-stage rotor, and obtain the third-stage front end axial clearance parameter and the third-stage rear end axial clearance parameter of the third-stage rotor based on the axial displacement parameter, the temperature difference parameter, the preset assembly clearance parameter of each stage of the rotor, the end position parameter of each stage of the rotor, the initial axial size parameter of each stage of the rotor and the thermal expansion coefficient of each stage of the rotor.

[0079] Please continue reading Figure 4 In some embodiments, the controller 20 further includes a storage module 260. The storage module 260 is electrically connected to the comparison module 220, the first calculation module 240, and the second calculation module 250. The displacement alarm threshold, the normal temperature parameter, the preset assembly clearance parameter of each stage of the rotor, the end position parameter of each stage of the rotor, the initial axial dimension parameter of each stage of the rotor, and the thermal expansion coefficient of each stage of the rotor are all stored in the storage module 260.

[0080] It can be understood that the storage module 260 is used for data storage to store displacement alarm thresholds, normal temperature parameters, preset assembly clearance parameters of each stage of the rotor, end position parameters of each stage of the rotor, initial axial dimension parameters of each stage of the rotor, and thermal expansion coefficient of each stage of the rotor.

[0081] The storage module 260 is electrically connected to the first calculation module 240, and is used to send the normal temperature parameters to the first calculation module 240. Of course, the first calculation module 240 can also send the calculated temperature difference parameters to the storage module 260 for storage, so as to view the temperature difference data during the maintenance process.

[0082] The storage module 260 is electrically connected to the second calculation module 250, and is used to send the preset assembly clearance parameters of each stage of the rotor, the end position parameters of each stage of the rotor, the initial axial size parameters of each stage of the rotor, and the thermal expansion coefficient of each stage of the rotor to the second calculation module 250. Of course, the second calculation module 250 can also send the calculated axial clearance parameters of the i-th stage of the rotor and the corresponding partition to the storage module 260 for storage, so as to store the axial clearance parameters of each stage of the rotor in real time, which is conducive to judging the time point of the fault occurrence during the maintenance process.

[0083] The storage module 260 is also electrically connected to the comparison module 220, and is used to send the displacement alarm threshold to the comparison module 220. Of course, the comparison module 220 can also send an alarm signal to the storage module 260, so as to record each alarm time.

[0084] In some embodiments, the storage module 260 can be configured as a solid-state memory, such as a solid-state hard disk. The storage module 260 can also be configured as a read-only memory so that data is not lost when power is off.

[0085] In some embodiments, the storage module 260 also stores an axial clearance threshold. The axial clearance threshold includes at least two sub-thresholds. The sub-threshold is defined as an i-th level sub-threshold based on the corresponding relationship with the rotor. The i-th level sub-threshold corresponds to the i-th level rotor. The comparison module 220 also outputs an alarm signal based on the i-th level axial clearance parameter being greater than or equal to the i-th level sub-threshold.

[0086] It can be understood that, based on the calculation of the aforementioned second calculation module 250, the axial clearance parameters of each stage of the rotor can be obtained. When judging each stage of the rotor, it is necessary to compare the axial clearance threshold of each stage of the rotor. As a result, at least two sub-thresholds corresponding to the rotor are stored in the storage module 260. The i-th stage axial clearance parameter is compared with the i-th stage sub-threshold. If the i-th stage axial clearance parameter is less than the i-th stage sub-threshold, no alarm is given. At this time, the vacuum pump will not get stuck, and the vacuum pump can continue to work normally. If the i-th stage axial clearance parameter is greater than or equal to the i-th stage sub-threshold, an alarm is given. At this time, the axial clearance of the i-th stage rotor is too small, and the vacuum pump is at risk of getting stuck. The operator can detect the i-th stage rotor of the vacuum pump based on the alarm information, and adjust the axial clearance of the i-th stage rotor to prevent the vacuum pump from getting stuck.

[0087] Therefore, based on the comparison between the i-th level axial clearance parameter and the i-th level sub-threshold, the axial clearance of each level of the vacuum pump rotor can be monitored in real time, and the i-th level rotor with problems can be accurately repaired, which can improve the technical problem of the vacuum pump getting stuck due to the small axial clearance of the vacuum pump shaft 40 and improve the maintenance efficiency.

[0088] Please continue reading Figure 4 In some embodiments, the controller 20 further includes a signal processing module 270. The signal processing module 270 is electrically connected to the signal receiving module 210, and is used to convert the axial displacement parameter into a first digital signal. The signal processing module 270 is also electrically connected to the temperature sensor 30, and is used to convert the temperature parameter into a second digital signal. The comparison module 220 is electrically connected to the signal processing module 270, and is used to compare the first digital signal with the displacement alarm threshold. The first calculation module 240 is electrically connected to the signal processing module 270 to obtain the temperature difference parameter based on the second digital signal and the normal temperature parameter.

[0089] It is understandable that the axial displacement parameter obtained by the displacement sensor 10 and the temperature parameter obtained by the temperature sensor 30 are both analog signals. The signal processing module 270 can realize analog-to-digital conversion. The signal processing module 270 converts the axial displacement parameter into a first digital signal and converts the temperature parameter into a second digital signal to realize digital comparison, digital calculation and digital display.

[0090] The signal processing module 270 may be a digital-to-analog converter, for example, an integral digital-to-analog converter, a successive approximation digital-to-analog converter, a parallel comparison type / serial-parallel type digital-to-analog converter, etc.

[0091] In some embodiments, the signal processing module 270 may also have functions of isolating interference, amplifying signals, filtering, etc. For example, the signal processing module 270 integrates a digital-to-analog converter, a signal amplifier, a filter, and the like.

[0092] Please continue reading Figure 4 In some embodiments, the controller 20 further includes a display module 280. The display module 280 is electrically connected to the signal processing module 270 and is used to receive the first digital signal and the second digital signal to digitally display the axial displacement parameter and the temperature parameter of the space where the rotating shaft 40 is located.

[0093] It is understandable that after receiving the first digital signal and the second digital signal, the display module 280 can directly display the axial displacement parameter and the temperature parameter in digital form, so as to directly observe the axial displacement value and the temperature value.

[0094] The display module 280 may be a display screen, a touch screen, or the like.

[0095] In some embodiments, the display module 280 may also be electrically connected to the first calculation module 240 to receive the temperature parameter, so that the difference between the internal temperature of the cavity and the external environment temperature may be displayed on the display module 280 .

[0096] In some embodiments, the display module 280 may also be electrically connected to the second calculation module 250 to receive the axial clearance parameter of each stage of the rotor. Thus, the current axial clearance parameter of each stage of the rotor may be displayed on the display module 280 .

[0097] On the other hand, Figures 1 to 3 As shown, the embodiment of the present application further provides a vacuum pump. The vacuum pump comprises a pump body assembly 510 and a monitoring mechanism as in the above-mentioned embodiment. The rotating shaft 40 is installed in the pump body assembly 510. The displacement sensor 10 is arranged on the vacuum pump near the end of the rotating shaft 40.

[0098] It is understandable that the axial displacement parameter of the rotating shaft 40 is obtained by the displacement sensor 10, and the controller 20 determines whether to alarm based on the comparison result of the axial displacement parameter and the displacement alarm threshold. When the axial displacement parameter is less than the displacement alarm threshold, no alarm is given. At this time, the vacuum pump will not get stuck, and the vacuum pump can continue to work normally. When the axial displacement parameter is greater than or equal to the displacement alarm threshold, an alarm is given. At this time, the axial displacement of the rotating shaft 40 is large, which will cause the axial clearance of the rotating shaft 40 to be too small, and the vacuum pump is at risk of getting stuck. The operator can detect the vacuum pump based on the alarm information, thereby adjusting the axial clearance of the rotating shaft 40 to prevent the vacuum pump from getting stuck. Thus, the axial clearance of the rotating shaft 40 of the vacuum pump can be monitored in real time to improve the technical problem of the vacuum pump getting stuck due to the small axial clearance of the rotating shaft 40 of the vacuum pump.

[0099] like Figure 1 As shown, the pump body assembly 510 may include a lower housing and an upper housing covering the lower housing. The upper housing and the lower housing may be fixedly connected by fasteners such as bolts. After the upper housing and the lower housing are covered, a cavity is formed inside, and the rotating shaft 40 is disposed in the cavity.

[0100] Please continue reading Figure 1 In some embodiments, the vacuum pump further includes a first bearing plate 520 and a second bearing plate 530. The first bearing plate 520 and the second bearing plate 530 are disposed on opposite sides of the pump body assembly 510. The two ends of the rotating shaft 40 are rotatably connected to the first bearing plate 520 and the second bearing plate 530, respectively.

[0101] The first bearing plate 520 and the second bearing plate 530 are respectively connected to both sides of the pump body assembly 510, so that both ends of the rotating shaft 40 can be connected to the bearings. The first bearing plate 520 can be fixed to one side of the pump body assembly 510 by fasteners such as bolts, and the second bearing plate 530 can be fixed to the other side of the pump body assembly 510 by fasteners such as bolts.

[0102] Please continue reading Figure 1 In some embodiments, the first bearing plate 520 may include a first plate body and a first bearing. The first plate body is provided with at least one first mounting hole, and a first bearing is installed in each first mounting hole. The second bearing plate 530 may include a second plate body and a second bearing. The second plate body is provided with at least one second mounting hole, and a second bearing is installed in each second mounting hole. The two ends of the rotating shaft 40 may be connected to the first bearing and the second bearing, respectively.

[0103] like Figure 1 and Figure 3 As shown, in some embodiments, the vacuum pump further includes an end cover 540. The end cover 540 is connected to the first bearing plate 520 or the second bearing plate 530. The end cover 540 is configured with a measuring hole 550. The measuring hole 550 is coaxially arranged with the rotating shaft 40. The displacement sensor 10 is installed in the measuring hole 550.

[0104] The end cover 540 can close the side of the vacuum pump away from the motor assembly 560. When the motor assembly 560 is connected to the first bearing plate 520, the end cover 540 is connected to the second bearing plate 530. When the motor assembly 560 is connected to the second bearing plate 530, the end cover 540 is connected to the first bearing plate 520. The measuring hole 550 constructed on the end cover 540 is used to install the displacement sensor 10, so that the axial displacement of the internal rotating shaft 40 is monitored by the displacement sensor 10 to obtain the axial displacement parameters of the rotating shaft 40.

[0105] The measuring hole 550 is coaxially arranged with the rotating shaft 40 , that is, the hole center of the measuring hole 550 is coaxial with the axial direction of the rotating shaft 40 , so as to ensure the accuracy of the displacement sensor 10 in measuring the axial displacement.

[0106] Please continue reading Figure 2 In some embodiments, at least two rotating shafts 40 are provided. At least two rotating shafts 40 are spaced apart along the radial direction thereof. At least two measuring holes 550 are spaced apart on the end cover 540. A displacement sensor 10 is installed in each measuring hole 550. Each displacement sensor 10 obtains the axial displacement parameter of a rotating shaft 40 respectively.

[0107] At least two rotating shafts 40 can form a shaft system component of the vacuum pump to achieve multi-shaft transmission. For each rotating shaft 40, a displacement sensor 10 is arranged in each measuring hole 550, so as to monitor each rotating shaft 40 respectively.

[0108] like Figure 1 As shown, in some embodiments, the vacuum pump further includes a motor assembly 560 and a gear box assembly 570. One side of the gear box assembly 570 is connected to the motor assembly 560. The other side of the gear box assembly 570 is connected to the pump body assembly 510. The output shaft of the motor assembly 560 is in driving connection with the first end of the gear box assembly 570, and the rotating shaft 40 is in driving connection with the second end of the gear box assembly 570.

[0109] The motor assembly 560 is used as a driving structure to drive the gears in the gearbox assembly 570 to rotate. A gear pair connected to the gearbox assembly 570 can be installed in the gearbox assembly 570, and the gearbox assembly 570 can be used as a reduction box to change the rotation speed. After the driving gear of the output shaft of the motor assembly 560 rotates, the gearbox assembly 570 can change the rotation speed and transmit it to the rotating shaft 40 at an appropriate rotation speed, thereby realizing the rotation of the rotating shaft 40.

[0110] In another aspect, the present application also provides a monitoring method. The monitoring method is used to monitor the axial displacement of the rotating shaft 40 of the vacuum pump. The monitoring method includes:

[0111] Step A: obtaining the axial displacement parameters of the rotating shaft 40.

[0112] Step B: compare the axial displacement parameter with the set displacement alarm threshold.

[0113] Step C: in response to the axial displacement parameter being greater than or equal to the displacement alarm threshold, an alarm is issued.

[0114] It is understandable that by obtaining the axial displacement parameter of the rotating shaft 40, it is determined whether to alarm based on the comparison result of the axial displacement parameter and the displacement alarm threshold. When the axial displacement parameter is less than the displacement alarm threshold, no alarm is given. At this time, the vacuum pump will not get stuck, and the vacuum pump can continue to work normally. When the axial displacement parameter is greater than or equal to the displacement alarm threshold, an alarm is given. At this time, the axial displacement of the rotating shaft 40 is large, which will cause the axial clearance of the rotating shaft 40 to be too small, and the vacuum pump is at risk of getting stuck. The operator can detect the vacuum pump based on the alarm information, thereby adjusting the axial clearance of the rotating shaft 40 to prevent the vacuum pump from getting stuck. Thus, the axial clearance of the rotating shaft 40 of the vacuum pump can be monitored in real time to improve the technical problem of the vacuum pump getting stuck due to the small axial clearance of the rotating shaft 40 of the vacuum pump.

[0115] The axial displacement parameter of the rotating shaft 40 can be obtained by the displacement sensor 10. The axial displacement parameter can be compared with the set displacement alarm threshold by the comparison module 220. The alarm module 230 can give an alarm.

[0116] In some embodiments, the displacement alarm threshold is less than the wear threshold of the shaft. It is understandable that when an alarm is issued in response to the axial displacement parameter being greater than or equal to the displacement alarm threshold, the shaft is in an unworn state. Then the alarm information can be used as a risk warning alarm to remind the staff of the risk of the vacuum pump being stuck later.

[0117] In some embodiments, the displacement alarm threshold is equal to the wear threshold of the shaft. It is understandable that when an alarm is issued in response to the axial displacement parameter being greater than or equal to the displacement alarm threshold, the shaft has been worn. The alarm information can be used as a fault prompt alarm to remind the staff to stop the machine for maintenance.

[0118] In some embodiments, the rotating shaft 40 includes at least two rotors spaced apart in sequence along its axial direction, and the rotor is defined as an i-th rotor based on its relative position to the displacement sensor 10 mounted on the vacuum pump, where i is an integer greater than or equal to 1, and the rotor close to the displacement sensor 10 is the first-stage rotor.

[0119] The rotating shaft 40 in the pump body assembly 510 of the vacuum pump includes a plurality of rotors which are sequentially spaced apart along the axial direction.

[0120] When the vacuum pump is working continuously, each rotor may be deformed due to the increase of ambient temperature. Then the axial clearance between each rotor and the corresponding stator may change. Therefore, after defining the rotor of each stage, it is convenient to calculate the axial clearance of each stage rotor later.

[0121] In some embodiments, obtaining the axial displacement parameter of the rotating shaft 40 includes:

[0122] The axial displacement parameter of the first-stage rotor at one end close to the displacement sensor 10 is obtained.

[0123] Since the first-stage rotor is the rotor closest to the displacement sensor 10, the displacement sensor 10 will act on the first-stage rotor. The first-stage rotor has a front end close to the displacement sensor 10 and a rear end away from the displacement sensor 10. The displacement sensor 10 is used to obtain the axial displacement parameter of the front end of the first-stage rotor.

[0124] In some embodiments, each stage of the rotor corresponds to a stator. A partition is provided between each two adjacent stages of the stator. The gap between each stage of the rotor and the corresponding partition is defined as the axial gap parameter of the rotor.

[0125] It is understandable that, based on the number of rotors being set to at least two, the number of stators is also set to at least two. At least two stators can be defined as the i-th stage stator based on the corresponding rotors. Two adjacent stages of stators are separated by partitions. The partitions are annular partitions so that the shaft can pass through each partition. The axial clearance parameter of the rotor is defined as the gap between each stage of the rotor and the corresponding partition. It is understandable that the rotor needs to form a gap with the partition to prevent the partition from interfering with the rotation of the rotor. When the rotor abuts against the partition, it may cause pump jamming and other phenomena.

[0126] In some embodiments, the monitoring method further includes: acquiring a temperature parameter of a space where the rotating shaft 40 is located, and calculating a temperature difference parameter between the temperature parameter and a set normal temperature parameter.

[0127] It is understandable that by obtaining the temperature parameters of the space where the shaft 40 is located and performing difference calculation with the set normal temperature parameters, the temperature difference parameters of the shaft 40 can be obtained. Based on the phenomenon of thermal expansion and contraction, it can be known that the shaft 40 will expand after heating. The acquisition of the temperature difference parameters facilitates the subsequent calculation of the axial clearance of each stage of the rotor.

[0128] After the step of obtaining the axial displacement parameter of the first-stage rotor near the end of the displacement sensor 10, the monitoring method further includes:

[0129] Based on the axial displacement parameters, temperature difference parameters and preset parameters, the axial clearance parameters of each stage of the rotor are obtained.

[0130] In response to the axial displacement parameter being less than the displacement alarm threshold, each level of axial clearance parameter is compared with a corresponding sub-threshold.

[0131] In response to the i-th level axial clearance parameter being less than or equal to the i-th level sub-threshold, an alarm is issued.

[0132] It is understandable that after the axial clearance parameters of each stage of the rotor are obtained, real-time monitoring can be performed on each stage of the rotor to prevent the axial clearance of the rotor far away from the displacement sensor 10 from being too small, thereby causing the vacuum pump to get stuck.

[0133] It is understandable that when the axial displacement parameter does not trigger an alarm, the axial clearance parameters of each level can be further compared to achieve multi-dimensional alarm monitoring.

[0134] Compare the i-th level axial clearance parameter with the i-th level sub-threshold. If the i-th level axial clearance parameter is greater than the i-th level sub-threshold, no alarm will be issued. At this time, the vacuum pump will not get stuck and the vacuum pump can continue to work normally. If the i-th level axial clearance parameter is less than or equal to the i-th level sub-threshold, an alarm will be issued. At this time, the axial clearance of the i-th level rotor is too small and the vacuum pump is at risk of getting stuck. The operator can detect the i-th level rotor of the vacuum pump based on the alarm information, and adjust the axial clearance of the i-th level rotor to prevent the vacuum pump from getting stuck.

[0135] Therefore, based on the comparison between the i-th level axial clearance parameter and the i-th level sub-threshold, the axial clearance of each level of the vacuum pump rotor can be monitored in real time, and the i-th level rotor with problems can be accurately repaired, which can improve the technical problem of the vacuum pump getting stuck due to the small axial clearance of the vacuum pump shaft 40, realize risk alarm, and improve maintenance efficiency.

[0136] When the axial clearance parameter of each level is compared with the corresponding sub-threshold, the axial clearance parameter of each level is synchronously compared with the corresponding sub-threshold. If the axial clearance parameter of any level is less than or equal to the corresponding sub-threshold, an alarm is issued.

[0137] In some embodiments, the preset parameters include preset assembly clearance parameters of each stage of the rotor, end position parameters of each stage of the rotor, initial axial dimension parameters of each stage of the rotor, and thermal expansion coefficient of each stage of the rotor.

[0138] The initial axial dimension parameter of each stage of the rotor is the initial length of the rotor. For example, the initial axial dimension parameter of the second stage rotor is the initial length parameter of the second stage rotor.

[0139] The thermal expansion coefficient of each stage of the rotor is related to the material of the rotor of that stage. When each stage of the rotor of the shaft 40 is made of the same material, the thermal expansion coefficient of each stage of the rotor α i When each stage of the rotor of the rotating shaft 40 is made of different materials, the thermal expansion coefficient α of each stage of the rotor is i different.

[0140] The end position parameters of the rotor include a front end parameter and a rear end parameter, the front end parameter is 1, and the rear end parameter is -1, wherein the front end is the end of the rotor close to the displacement sensor 10, and the rear end is the end of the rotor away from the displacement sensor 10.

[0141] In some embodiments, based on the axial displacement parameter, the temperature difference parameter and the preset parameter, a calculation formula for obtaining the axial clearance parameter of each stage of the rotor includes:

[0142]

[0143] Where i is the position of the rotor. j is the end position parameter of the rotor. The front end of the rotor corresponds to j = 1. The rear end of the rotor corresponds to j = -1. ij is the axial clearance parameter between the jth end of the i-th stage rotor and the corresponding partition. 装ij is the preset assembly clearance parameter between the jth end of the i-th stage rotor and the corresponding partition. 位 is the axial displacement parameter measured by the displacement sensor 10. i is the thermal expansion coefficient of the i-th stage rotor. i is the initial axial dimension parameter of the i-th stage rotor. ΔT is the temperature difference parameter between the temperature parameter of the space where the rotating shaft 40 is located and the set normal temperature parameter.

[0144] It is understandable that, based on the above calculation formula, the axial clearance parameters of each end of each stage of the rotor can be calculated, thereby achieving real-time monitoring of the axial clearance parameters of each stage of the rotor.

[0145] For example, when it is necessary to obtain the axial clearance parameter of the front end of the fifth-stage rotor relative to the fifth-stage stator, i=5, j=1. Substituting into the formula:

[0146] For example, when the axial clearance parameter of the rear end of the third-stage rotor needs to be obtained, i=3, j=-1. Substituting into the formula:

[0147] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A monitoring mechanism for monitoring the axial displacement of a rotating shaft of a vacuum pump, characterized in that: include: A displacement sensor, used to obtain the axial displacement parameters of the rotating shaft; The controller is electrically connected to the displacement sensor and is used to receive the axial displacement parameter. A displacement alarm threshold is set in the controller. The controller generates an alarm in response to the axial displacement parameter being greater than or equal to the displacement alarm threshold.

2. The monitoring mechanism according to claim 1, characterized in that: The controller comprises: A signal receiving module, electrically connected to the displacement sensor, and configured to receive the axial displacement parameter; a comparison module, electrically connected to the signal receiving module, and configured to compare the axial displacement parameter with the displacement alarm threshold, wherein the comparison module outputs an alarm signal based on the axial displacement parameter being greater than or equal to the displacement alarm threshold; The alarm module is electrically connected to the comparison module and is used to receive the alarm signal and generate an alarm.

3. The monitoring mechanism according to claim 2, characterized in that: The monitoring agency also includes: A temperature sensor, used to obtain temperature parameters of the space where the rotating shaft is located; The controller is set with normal temperature parameters, and the controller also includes: The first calculation module is electrically connected to the temperature sensor, and is used to obtain a temperature difference parameter between the temperature parameter and the normal temperature parameter.

4. The monitoring mechanism according to claim 3, characterized in that: The controller further comprises: A storage module is electrically connected to the comparison module and the first calculation module, and the displacement alarm threshold and the normal temperature parameter are both stored in the storage module.

5. The monitoring mechanism according to claim 3 or 4, characterized in that: The controller further comprises: A signal processing module is electrically connected to the signal receiving module and is used to convert the axial displacement parameter into a first digital signal. The signal processing module is also electrically connected to the temperature sensor and is used to convert the temperature parameter into a second digital signal. The comparison module is electrically connected to the signal processing module and is used to compare the first digital signal with the displacement alarm threshold. The first calculation module is electrically connected to the signal processing module to obtain the temperature difference parameter based on the second digital signal and the normal temperature parameter.

6. The monitoring mechanism according to claim 5, characterized in that: The controller further comprises: The display module is electrically connected to the signal processing module and is used to receive the first digital signal and the second digital signal to digitally display the axial displacement parameter and the temperature parameter of the space where the rotating shaft is located.

7. A vacuum pump, characterized in that: include: Pump body assembly; The monitoring mechanism according to any one of claims 1 to 6; Wherein, the rotating shaft is installed in the pump body assembly, and the displacement sensor is arranged on the vacuum pump near the end of the rotating shaft.

8. The vacuum pump according to claim 7, characterized in that The vacuum pump also includes: The first bearing plate and the second bearing plate are arranged on opposite sides of the pump body assembly, wherein two ends of the rotating shaft are rotatably connected to the first bearing plate and the second bearing plate respectively.

9. The vacuum pump according to claim 8, characterized in that The vacuum pump also includes: The end cover is connected to the first bearing plate or the second bearing plate. The end cover is configured with a measuring hole. The measuring hole is coaxially arranged with the rotating shaft. The displacement sensor is installed in the measuring hole.

10. The vacuum pump according to claim 9, characterized in that There are at least two rotating shafts, at least two rotating shafts are spaced apart along their radial direction, at least two measuring holes are spaced apart on the end cover, a displacement sensor is installed in each measuring hole, and each displacement sensor obtains an axial displacement parameter of the rotating shaft respectively.

11. The vacuum pump according to any one of claims 7 to 10, characterized in that: The vacuum pump also includes: Motor components; A gear box assembly, one side of which is connected to the motor assembly, and the other side of which is connected to the pump assembly; Wherein, the output shaft of the motor assembly is transmission-connected to the first end of the gear box assembly, and the rotating shaft is transmission-connected to the second end of the gear box assembly.

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