KR20210093663A - Compressor and Chiller including the same - Google Patents

Abstract

The present invention relates to a compressor and a refrigerator including the same. According to an embodiment of the present invention, a compressor may comprise: a motor; a first rotating shaft coupled with the motor to rotate; a first gear formed on the first rotating shaft; a second rotating shaft coupled to at least one impeller and rotating; a second gear formed on the second rotating shaft and meshing with the first gear; and a controller which calculates the gear meshing frequencies of the first gear and the second gear, determines whether abnormal vibration between the first gear and the second gear occur at the calculated gear meshing frequencies, and controls to output an alarm when it is determined that abnormal vibration has occurred. Accordingly, it is possible to accurately monitor the failure of a gearbox of a refrigerator, there is an effect that does not increase the manufacturing cost of the refrigerator.

Description

Compressor and Chiller including the same

The present invention relates to a compressor and a refrigerator including the same, and more particularly, by processing the displacement information or motor bearing current signal measured by the gap sensor, analyzing the signal at the gear meshing frequency, and determining whether abnormal vibration of the gear occurs , It relates to a compressor capable of accurately monitoring the failure of the gearbox of the compressor, and a refrigerator including the same.

In general, a chiller is a device for performing heat exchange between cold water and cooling water using a refrigerant, and heat exchange is performed between a refrigerant circulating in a chiller and cold water circulating between a cold water demander and a chiller to cool the cold water. Since such a chiller is used for purposes such as large-scale air conditioning, stable operation and high reliability of the device are required.

The structure of the conventional chiller system will be described as follows.

Referring to FIG. 1 , the main configuration of a conventional chiller system 1 includes a compressor 10 , a condenser 20 , an expansion mechanism 30 , an evaporator 40 , and a controller 50 . In addition, the conventional chiller system 1 includes a refrigerant passage A, and a load 60 is connected thereto.

The compressor 10 is a device for compressing a gas such as air or refrigerant gas, and is formed to compress the refrigerant and provide it to the condenser 20 . The compressor 10 includes an impeller for compressing the refrigerant, a rotating shaft connected to the impeller, and a motor for rotating the rotating shaft.

The condenser 20 is formed so as to cool the refrigerant by exchanging heat with the high-temperature and high-pressure refrigerant discharged from the compressor 10 and passing through the condenser 20 .

The expansion mechanism 30 sends the liquid refrigerant to the evaporator 40 , and the refrigerant of high pressure passes through the expansion valve to change to low temperature and low pressure.

The evaporator 40 is formed to cool the cold water supplied to the load 50 while the refrigerant evaporates.

The refrigerant passage A is a passage in which the refrigerant compressed in the compressor 10 flows from the compressor 10 to the condenser 20 , and the refrigerant condensed in the condenser 20 is transferred from the condenser 20 to the expansion mechanism 30 . A flow path, a flow path through which the refrigerant expanded by the expansion mechanism 30 flows from the expansion mechanism 30 to the evaporator 40, and a flow path through which the refrigerant evaporated in the evaporator 40 flows from the evaporator 40 to the compressor 10 made in euros.

The conventional chiller system 1 is provided with temperature sensors 41 and 42 at each cold water inlet and outlet of the evaporator 40 connected to the load 50 in order to determine whether the chiller is in an abnormal state, and the cold water inlet A flow meter 43 is provided.

The temperature sensors 41 and 42 detect the temperature at the inlet and outlet of the cold water, respectively, and transmit it to the controller 50, and the flow meter 43 detects the flow rate circulating the evaporator 40 and the load 50, and the controller ( 50) is sent.

The controller 50 receives the detected temperature and the detected flow rate information, and calculates the amount of load currently applied to the chiller 1 based on the received information. The controller 50 calculates the range of the normal opening degree of the expansion valve (not shown) of the expansion mechanism 30 from the calculated load amount.

The controller 50 receives the current opening amount information from the expansion valve of the expansion mechanism 30 , compares it with the calculated normal opening amount range, and when the received current opening amount information is outside the calculated normal opening amount range, the chiller (1) is judged to be in an abnormal state.

However, the conventional chiller system 1 can only determine whether there is an abnormality in the refrigerant cycle or the coolant cycle, and the structural failure of devices such as gears and impellers of the compressor 10 constituting the chiller 1 is determined The problem is that it cannot be done.

In addition, in order to monitor a structural failure of a device such as a gear and an impeller of a compressor, various types of sensors such as a vibration sensor and a displacement sensor must be applied to each part of the compressor, thereby increasing the manufacturing cost.

In order to solve the above problem, the present invention processes the displacement information or the motor bearing current signal measured by the gap sensor, analyzes it at the gear meshing frequency, determines whether abnormal vibration of the gear occurs, and malfunctions the gearbox of the compressor. The purpose is to accurately monitor whether

In addition, the present invention, in order to solve the above problems, by using a gap sensor or motor bearing included in the conventional compressor to determine whether abnormal vibration of the gear occurs, the purpose is not to increase the manufacturing cost of the compressor or chiller there is.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description.

Compressor according to an embodiment of the present invention for achieving the above object, a motor, a first rotating shaft that rotates in combination with a motor, a first gear formed on the first rotating shaft, a first rotating in combination with at least one impeller 2 rotation shaft, the second gear formed on the second rotation shaft and meshed with the first gear, and the gear meshing frequencies of the first gear and the second gear are calculated, and abnormal vibration of the first gear and the second gear at the calculated gear meshing frequency It may include a controller that determines whether an occurrence occurs, and controls to output an alarm when it is determined that abnormal vibration has occurred.

On the other hand, in the compressor according to an embodiment of the present invention for achieving the above object, the controller receives the rotation speed information of the motor from the inverter that outputs AC power to the motor, the rotation speed of the motor, the number of teeth of the first gear, The gear meshing frequency may be calculated using the number of teeth of the second gear.

On the other hand, the compressor according to an embodiment of the present invention for achieving the above object, further comprising a gap sensor for detecting a distance to the first rotation shaft, the controller generates abnormal vibration based on the displacement information measured by the gap sensor can determine whether

On the other hand, the compressor according to an embodiment of the present invention for achieving the above object, further comprising at least one or more motor bearings limiting the vibration of the first rotating shaft in the vertical direction of the axis, the controller is the current signal of the motor bearing It can be determined whether abnormal vibration has occurred based on the.

On the other hand, in the compressor according to an embodiment of the present invention for achieving the above object, the controller obtains the displacement information measured by the gap sensor or the current signal of the motor bearing when the motor rotates and converts it into a frequency component, and gear mesh The converted displacement information or the converted current signal in frequency may be compared with a preset reference value, and when it is greater or less than the preset reference value, it may be determined that abnormal vibration has occurred.

On the other hand, in the compressor according to an embodiment of the present invention for achieving the above object, the controller converts the displacement information or current signal obtained when the motor is in a normal operating state into a frequency component, and the converted displacement at the gear meshing frequency Information or a converted current signal can be set as a reference value.

On the other hand, in the compressor according to an embodiment of the present invention for achieving the above object, the controller may set the reference value by acquiring and averaging the displacement information or the current signal a plurality of times when the motor is in a normal operating state.

On the other hand, the compressor according to an embodiment of the present invention for achieving the above object, further comprising a display, the controller, the converted displacement information or the converted current signal at the gear meshing frequency is greater than the reference value by a first value or more or small, it can be controlled to show a caution alarm on the display.

On the other hand, in the compressor according to an embodiment of the present invention for achieving the above object, when the converted displacement information or the converted current signal at the gear meshing frequency is larger or smaller than the reference value by a second value or more, the Control to display a warning alarm and stop the operation of the compressor, the second value may be greater than the first value.

On the other hand, in the compressor according to an embodiment of the present invention for achieving the above object, when the controller stops the operation of the compressor, the storage box inspection guide information is controlled to be displayed on the display, and the gearbox inspection result is normal, or the standard If more than a certain time has elapsed after setting the value, the reference value can be updated and reset.

On the other hand, the refrigerator according to an embodiment of the present invention for achieving the above object includes a condenser, an evaporator and a compressor, and the compressor is a motor, a first rotating shaft coupled with the motor to rotate, and a first formed on the first rotating shaft 1 gear, a second rotation shaft coupled to at least one impeller to rotate, a second gear formed on the second rotation shaft and meshed with the first gear, and the gear meshing frequencies of the first gear and the second gear are calculated, It may include a controller that determines whether abnormal vibration occurs in the first gear or the second gear at the gear meshing frequency, and controls to output an alarm when it is determined that the abnormal vibration occurs.

The details of other embodiments are included in the detailed description and drawings.

According to the present invention, there are the following effects.

A compressor and a refrigerator including the same according to an embodiment of the present invention signal-process the displacement information or motor bearing current signal measured by the gap sensor, analyze it at the gear meshing frequency, determine whether abnormal vibration of the gear occurs, It has the effect of accurately monitoring the failure of the gearbox of

In addition, the compressor and the refrigerator including the same according to an embodiment of the present invention determine whether abnormal vibration of the gear occurs using a gap sensor or motor bearing included in a conventional compressor, thereby increasing the manufacturing cost of the compressor or chiller. It has no effect.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those of ordinary skill in the art from the description of the claims.

1 is a view showing the structure of a conventional general chiller and a compressor included therein.
2 is a view showing a refrigerator according to an embodiment of the present invention.
3 is a diagram illustrating a structure of a compressor according to an embodiment of the present invention.
4 is a diagram illustrating a configuration of a controller according to an embodiment of the present invention.
5 is a diagram illustrating a gear connection structure referenced in calculating a gear meshing frequency of the compressor of FIG. 3 .
6 is a view for explaining conversion of a measured value into a frequency component in the compressor according to an embodiment of the present invention.
7 is a diagram for explaining changing a reference value of a frequency domain in the compressor according to an embodiment of the present invention.
8 is a flowchart illustrating a method for determining whether abnormal vibration occurs in a compressor according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

Regardless of the reference numerals, the same or similar components are assigned the same reference numerals, and overlapping descriptions thereof will be omitted. The suffixes "module" and "part" for the components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have a meaning or role distinct from each other by themselves. Accordingly, the terms “module” and “unit” may be used interchangeably.

In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed herein is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention , should be understood to include equivalents or substitutes.

Terms including an ordinal number, such as first, second, etc., may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being “connected” or “connected” to another component, it is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as "comprises" or "have" are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

In the drawings, the thickness or size of each component is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size and area of each component do not fully reflect the actual size or area.

2 is a view showing a refrigerator 2 including a compressor 100 according to an embodiment of the present invention.

On the other hand, the compressor 100 according to an embodiment of the present invention not only functions as a part of a refrigerator, but also may be included in an air conditioner, and may be included in any device that compresses a gaseous material.

Referring to FIG. 2 , the refrigerator 2 according to an embodiment of the present invention includes a compressor 100 configured to compress a refrigerant, and a condenser 200 for condensing the refrigerant by exchanging heat with the refrigerant compressed in the compressor 100 and cooling water. ), an expander 300 that expands the refrigerant condensed in the condenser 200, and an evaporator 400 formed to heat-exchange the refrigerant expanded in the expander 300 with the cold water to cool the cold water with evaporation of the refrigerant. .

On the other hand, in the refrigerator 2 according to an embodiment of the present invention, the cooling water unit 600 is formed to cool the cooling water heat-exchanged with the refrigerant in the condenser 200 , the cold water cooled in the evaporator 400 and the air in the air conditioning space It may further include an air conditioning unit 500 for cooling the air in the air conditioning space by exchanging heat and a controller 700 for controlling the operation of the compressor.

The condenser 200 may provide a place for exchanging the high-pressure refrigerant compressed in the compressor 100 with the coolant flowing in from the cooling water unit 600 . The compressed high-pressure refrigerant is condensed through heat exchange with cooling water.

The condenser 200 may be configured as a shell-tube type heat exchanger. Specifically, the high-pressure refrigerant compressed in the compressor 100 is introduced into the condensing space 230 corresponding to the internal space of the condenser 200 through the condenser connection passage 160 . Also, the cooling water flow path 210 through which the cooling water introduced from the cooling water unit 600 may flow may be included in the condensing space 230 .

The cooling water flow path 210 may include a cooling water inflow path 211 through which the cooling water is introduced from the cooling water unit 600 and a cooling water discharge path 212 through which the cooling water is discharged to the cooling water unit 600 . The cooling water flowing into the cooling water inlet flow path 211 exchanges heat with the refrigerant inside the condensing space 230 , and then passes through the cooling water connection flow path 240 provided at one end inside the condenser 200 or outside the cooling water discharge flow path 212 . is introduced into

The cooling water unit 600 and the condenser 200 may be connected via the cooling water tube 220 . The cooling water tube 220 may be a passage through which the cooling water flows between the cooling water unit 600 and the condenser 200 . In addition, the cooling water tube 220 may be made of a material such as rubber so that the cooling water does not leak to the outside.

The cooling water tube 220 may include a cooling water inlet tube 221 connected to the cooling water inlet passage 211 and a cooling water discharge tube 222 connected to the cooling water discharge passage 212 .

Looking at the flow of the cooling water as a whole, the cooling water after heat exchange with air or liquid in the cooling water unit 600 is introduced into the condenser 200 through the cooling water inlet tube 221 . The cooling water introduced into the condenser 200 passes through the cooling water inflow path 211, the cooling water connection path 240, and the cooling water discharge path 212 provided in the condenser 200 in turn. After heat exchange with the refrigerant, the coolant flows back into the coolant unit 600 through the coolant discharge tube 222 .

Meanwhile, the cooling water unit 600 may air-cool the cooling water that has absorbed heat of the refrigerant through heat exchange in the condenser 200 . The cooling water unit 600 includes a main body 630 , a cooling water inlet pipe 610 that is an inlet through which the cooling water that has absorbed heat through the cooling water discharge tube 222 is introduced, and the cooling water after being cooled inside the cooling water unit 600 . may be composed of a cooling water discharge pipe 620 that is an outlet to which is discharged.

The cooling water unit 600 may use air to cool the cooling water introduced into the main body 630 . Specifically, the main body 630 may include a fan for generating a flow of air, and an air outlet 631 through which air is discharged and an air inlet 632 corresponding to an inlet through which air is introduced into the body 630 . ) may be included.

After the heat exchange, the air discharged from the air outlet 631 may be used for heating. The refrigerant after heat exchange in the condenser 200 is condensed and collected in the lower portion of the condensing space 230 . The accumulated refrigerant flows into the refrigerant box 250 provided in the condensing space 230 and then flows into the expander 300 .

The refrigerant box 250 may include a refrigerant inlet 251 . The refrigerant introduced into the refrigerant inlet 251 is discharged through the expansion mechanism connecting passage 260 . The expansion mechanism connection passage 260 may include an expansion mechanism connection passage inlet 261 , and the expansion mechanism connection passage inlet 261 may be located at a lower portion of the refrigerant box 250 .

The evaporator 400 may include an evaporation space 430 in which heat exchange occurs between the refrigerant expanded in the expander 300 and the cold water. The refrigerant that has passed through the expander 300 in the expansion mechanism connection passage 260 flows to the refrigerant injection device 450 provided in the evaporator 400 through the evaporator connection passage 360, and to the refrigerant injection device 450 It spreads evenly into the evaporator 400 through the provided refrigerant injection hole 451 .

In addition, in the evaporator 400, a cold water flow path 410 including a cold water inflow path 411 through which cold water flows into the evaporator 400 and a cold water discharge path 412 through which cold water is discharged to the outside of the evaporator 400 is provided. can be provided.

The cold water is introduced or discharged through the cold water tube 420 in communication with the air conditioning unit 500 provided outside the evaporator 400 . The cold water tube 420 includes a cold water inlet tube 421 , which is a passage for the cold water inside the air conditioning unit 500 to the evaporator 400 , and a passage for the cold water after heat exchange in the evaporator 400 , to the air conditioning unit 500 . It may be composed of a phosphorus cold water discharge tube 422 . That is, the cold water inlet tube 421 communicates with the cold water inlet passage 411 , and the cold water discharge tube 422 communicates with the cold water discharge passage 412 .

Looking at the flow of cold water, the cold water passes through the air conditioning unit 500 , the cold water inlet tube 421 , and the cold water inflow passage 411 , and the inner end of the evaporator 400 or the cold water connection provided on the outside of the evaporator 400 . After passing through the flow passage 440 , the cold water is introduced back into the air conditioning unit 500 through the cold water discharge passage 412 and the cold water discharge tube 422 .

The air conditioning unit 500 may exchange heat between the cold water cooled in the evaporator 400 and the air in the air conditioning space. The cold water cooled by the evaporator 400 absorbs heat from the air in the air conditioning unit 500 to enable indoor cooling. The air conditioning unit 500 may include a cold water discharge pipe 520 communicating with the cold water inlet tube 421 and a cold water inlet pipe 510 communicating with the cold water discharge tube 422 . The refrigerant after heat exchange in the evaporator 400 is introduced back into the compressor 100 through the compressor connection passage 460 .

Looking at the flow of the refrigerant, the refrigerant introduced into the compressor 100 through the compressor connection passage 460 is compressed in the circumferential direction by the action of the impellers 110 and 120, and then is discharged to the condenser connection passage 160. . The compressor connection passage 460 may be connected to the compressor 100 so that the refrigerant flows in a direction perpendicular to the rotation direction of the impellers 110 and 120 .

The controller 700 receives the rotation speed of the motor, calculates the gear meshing frequency, receives displacement information from the gap sensor 150, receives the current signal of the motor bearing 141, and converts the received information into a frequency component can do. The controller 700 may determine whether abnormal vibration of the gear occurs based on the gear meshing frequency in the frequency domain.

In addition, when it is determined that abnormal vibration occurs, the controller 700 may control an alarm to be displayed on the display, and may control the compressor 100 or the refrigerator 2 to stop the operation of the refrigerator 2 .

3 is a view showing the structure of the compressor 100 according to an embodiment of the present invention.

2 and 3, the compressor 100, one or more impellers 110 and 120 for sucking the refrigerant in the axial direction and compressing it in the centrifugal direction, the motor 131 that is accommodated in the motor housing and rotates, the motor ( 131) coupled to the rotating first rotation shaft 132, at least one motor bearing 141 supporting the first rotation shaft 132 so as to be rotatable in the air, and a bearing housing (not shown) supporting the motor bearing 141 ) and at least one gap sensor 150 for detecting a distance from the bearing part and the first rotation shaft 132 .

In addition, the compressor 100 is coupled to at least one or more impellers 110 and 120 to rotate the second rotating shaft 135 and at least one impeller bearing 142 for supporting the second rotating shaft 135 so as to be rotatable in the air. ) may be included.

Meanwhile, the compressor 100 may further include a thrust bearing (not shown) for limiting vibration of the second rotation shaft 135 in the axial direction.

The impellers 110 and 120 may be formed in one stage or two stages, or may be formed in a plurality of stages. The impellers 110 and 120 are connected to the second rotation shaft 135 and rotate by the second rotation shaft 135, and the refrigerant introduced in the axial direction is compressed by rotation in the centrifugal direction to make the refrigerant high pressure. there is.

The motor 131 may include a stator 134 and a rotor 133 , and may rotate the first rotation shaft 132 . The rotor 133 may be disposed on the outer periphery of the first rotation shaft 132 , and may rotate together with the first rotation shaft 132 . The stator 134 may be disposed inside the motor housing to surround the outer circumference of the rotor 133 . The motor 131 may have a structure that has a rotation shaft separate from the first rotation shaft 132 and transmits rotational force to the first rotation shaft 132 by a belt (not shown).

The first rotation shaft 132 may be connected to the motor 131 . The first rotation shaft 132 and the second rotation shaft 135 extend in the left and right directions of FIG. 3 . Hereinafter, the axial directions of the first rotation shaft 132 and the second rotation shaft 135 refer to left and right directions.

A first gear 136 may be formed or connected to the first rotation shaft 132 , and the first gear 136 may rotate according to the rotation of the first rotation shaft 132 . A second gear 137 may be formed or connected to the second rotation shaft 135 , and the second gear 137 may rotate according to the rotation of the second rotation shaft 135 . The first gear 136 may be positioned to mesh with the second gear 137 . Therefore, when the first gear 136 or the second gear 137 rotates, the second gear 137 or the first gear 136 may rotate together.

When the motor 131 rotates, the rotation is transmitted to the second gear 137 through the first gear 136 connected to the first rotation shaft 132 , and the impellers 110 and 120 while the second rotation shaft 135 rotates. ) can be rotated.

When the motor bearing 141 , the impeller bearing 142 , and the thrust bearing are magnetic bearings, it is preferable that the first rotating shaft 132 or the second rotating shaft 135 include a metal so as to be movable by magnetic force.

In order to prevent vibration in the axial direction of the first rotating shaft 132 or the second rotating shaft 135 , the thrust bearing has a predetermined area in a plane perpendicular to the axial direction of the first rotating shaft 132 or the second rotating shaft 135 . It is preferable to have Specifically, the first rotation shaft 132 or the second rotation shaft 135 may further include a thrust blade (not shown) to move the rotation shaft by means of a thrust bearing. The thrust blade may have a larger area than the cross-sectional area of the first rotation shaft 132 or the second rotation shaft 135 in a plane perpendicular to the axial direction. The thrust blade may be formed to extend in a rotational direction of the first rotational shaft 132 or the second rotational shaft 135 .

When the motor bearing 141, the impeller bearing 142, and the thrust bearing are magnetic bearings, the motor bearing 141, the impeller bearing 142, and the thrust bearing may be composed of a conductor, and a coil (not shown) may be wound. can In this case, the motor bearing 141 , the impeller bearing 142 , and the thrust bearing act like a magnet by the current flowing in the wound coil.

A plurality of motor bearings 141 and impeller bearings 142 may be provided to surround the first rotational shaft 132 and the second rotational shaft 135 with respect to the first rotational shaft 132 and the second rotational shaft 135, respectively. In addition, the thrust bearings may be provided adjacent to the thrust blades extending in the rotational radial direction of the first rotational shaft 132 or the second rotational shaft 135 , respectively.

The motor bearing 141 and the impeller bearing 142 may rotate without friction in a state in which the first rotation shaft 132 and the second rotation shaft 135 are suspended in the air, respectively. When the motor bearing 141 and the impeller bearing 142 are magnetic bearings, the first rotating shaft 132 and the second rotating shaft ( 135) will float in the air.

The thrust bearing restricts movement of the first rotation shaft 132 or the second rotation shaft 135 in axial vibration, and when a surge occurs, the first rotation shaft 132 or the second rotation shaft 135 moves in the axial direction. While moving to, it is possible to prevent collision with other components of the compressor 100 .

The motor bearing 141 , the impeller bearing 142 and the thrust bearing may be air foil bearings. In this case, the thrust bearing may include a disc-shaped plate (not shown), a plurality of bump foils (not shown) coupled to the plate, and a top foil having one end coupled to the plate and positioned above the bump foil. there is.

The plate may have a flat top surface and a shape in which a circular hole is included in a disk-shaped disk. A bump foil and a top foil may be attached to the upper surface through welding.

The gap sensor 150 may measure the movement in the vertical direction (direction orthogonal to the axial direction) of the first rotation shaft 132 . The gap sensor 150 may detect a distance from the first rotation shaft 132 , and may measure vertical movement or displacement information from a change in the sensed distance. Accordingly, the displacement information may be defined as change information of the position of the first rotation shaft 132 .

In addition, the gap sensor 150 may measure the axial movement of the first rotation shaft 132 . The gap sensor 150 may include a plurality of gap sensors. For example, the gap sensor 150 may include a first gap sensor 150 for measuring the vertical movement of the first rotation shaft 132 , and a first gap sensor 150 for measuring the horizontal movement of the first rotation shaft 132 . 2 It may further include a gap sensor (not shown). The second gap sensor may be axially spaced apart from one end of the first rotation shaft 132 in the axial direction.

The gap sensor 150 may transmit the measured displacement information to the controller 700 , and the controller 700 may detect an abnormality of the gearbox including the first gear 136 and the second gear 137 based on the displacement information. Vibration can be determined.

The current signal applied to the coil of the motor bearing 141 may be changed according to displacement information measured by the gap sensor 150 . Accordingly, the controller 700 may determine whether abnormal vibration occurs in the gearbox including the first gear 136 and the second gear 137 by using the current signal applied to the coil of the motor bearing 141 . .

4 is a diagram illustrating a configuration of a controller 700 according to an embodiment of the present invention. Referring to FIG. 4 , the controller 700 may include a processor 710 , a storage unit 720 , an A/D converter 730 , and an interface board 740 .

The processor 710 may execute a control algorithm to control the operation of the compressor 100 or the refrigerator 2 including the compressor 100 . The control algorithm may be implemented as a computer program and executed by the processor 710 , which will be apparent to those skilled in the art. Meanwhile, the controller 700 may further include a controller (not shown) that executes a function separate from the processor 710 .

The processor 710 may execute a control algorithm to control the speed of the motor 131 , or to control the opening degree of a valve included in the circulation passage (not shown) or the expander 300 .

The storage unit 720 may store a control algorithm. The control algorithm may be configured as a computer program or software and stored in the storage unit 720 .

The storage unit 720 is a flash memory type (flash memory type), a hard disk type (hard disk type), a multimedia card micro type (multimedia card micro type), card type memory (for example, SD or XD memory, etc.), Random Access Memory (RAM), Static Random Access Memory (SRAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), Programmable Read Only Memory (PROM) Magnetic Memory, Magnetic Disk, Optical Disk It may include at least one type of storage medium.

The A/D converter 730 may convert analog signals received from various sensors including the gap sensor 150 into digital signals. The digital signal converted by the A/D converter 730 may be provided to the processor 710 .

The interface board 740 may receive signals from various sensors and components in relation to the operation of the compressor 100 . For example, the interface board 740 may include temperature information of cold water discharged from the evaporator 400 to the cold water inlet tube 421 , cooling pressure information of the evaporator 400 and the condenser 200 , and discharge temperature of the compressor 100 . At least one of sensor information and oil temperature sensor information of the compressor 100 may be received.

The processor 710 of the controller 700 executes the control algorithm to calculate the gear mesh frequency (GMF) of the first gear 136 and the second gear 137, and from the calculated gear mesh frequency It may be determined whether abnormal vibration occurs between the first gear 136 and the second gear 137 . The processor 710 may control a display (not shown) to output an alarm when it is determined that abnormal vibration has occurred.

The processor 710 may obtain the displacement information measured by the gap sensor 150 or the current signal of the motor bearing 141 and convert it into frequency domain information. Meanwhile, the controller 700 may further include a digital signal processing chip (DSP), and the digital signal processing chip (not shown) converts the displacement information or the current signal to a fast Fourier transform (FFT). can be used to convert to frequency domain information.

The processor 710 may control the magnitude of the current applied to the motor bearing 141 to change based on the position information and the displacement information of the first rotation shaft 132 measured by the gap sensor 150 . Through this, the processor 710 may control the first rotation shaft 132 so that the position of the first rotation shaft 132 is within a position or position range in which a normal operation is possible.

The information converted by the processor 710 or the digital signal processing chip may include information having amplitudes at a plurality of frequencies. The processor 710 may determine whether abnormal vibration occurs by extracting only the gear meshing frequency or information corresponding to a predetermined frequency range based on the gear meshing frequency from the converted information. The processor 710 is a high pass filter (HPF, high pass filter) or a band pass filter (BPF, band pass filter) to extract only information corresponding to a gear meshing frequency or a predetermined frequency range based on the gear meshing frequency. A frequency filter can be used.

5 is a diagram illustrating a gear connection structure referenced for calculating the gear meshing frequency of the compressor of FIG. 3, and FIG. 6 is a diagram for explaining conversion of a measured value into a frequency component in the compressor according to an embodiment of the present invention. and FIG. 7 is a diagram for explaining changing a reference value of a frequency domain in the compressor according to an embodiment of the present invention.

Referring to FIG. 5 , the first gear 136 may mesh with the second gear 137 . The number of teeth of the first gear 136 is N1, and the number of teeth of the second gear 137 is N2. N1 and N2 are positive integers greater than or equal to 2;

When the motor 131 rotates at Z1 [Hz], the first gear 136 rotates at Z1 [Hz] by the rotation of the first rotation shaft 132 . In this case, the processor 710 may calculate the gear meshing frequency by using the rotation speed information of the motor 131 .

The gear meshing frequency is a value indicating the degree to which a pair of gears collide with each other as they rotate. The processor 710 may calculate the gear meshing frequency by using the number of teeth (the number of teeth) of the gear and the rotation speed of the gear. The gear meshing frequency may be calculated by multiplying the number of teeth of the gear by the rotation speed (Hz) of the gear. Alternatively, when the gear is a rack-and-pinion gear, the gear meshing frequency may be calculated by multiplying the rotational speed (Hz) of the motor, the number of teeth of the rack gear, and the number of teeth of the pinion gear.

For example, the processor 710 may calculate the gear meshing frequency as in Equation 1 below.

(Equation 1) GMF = N1 * Z1 [Hz]

Alternatively, the processor 710 may calculate the gear meshing frequency from the number of teeth of the second gear 137 and the rotation speed of the second gear 137 . Since the second gear 137 meshes with the first gear 136 and rotates, the rotation speed Z2 of the second gear 137 is equal to Z1 * (N1/N2). Accordingly, the processor 710 may calculate the gear meshing frequency as in Equation 2 below.

(Equation 2) GMF = N2 * Z2

= N2 * (Z1 * (N1/N2))

= N1 * Z1 [Hz]

Alternatively, the processor 710 may use the rotation speed of the motor 131, the number of teeth of the first gear 136, and the number of teeth of the second gear 137 to calculate the gear meshing frequency as shown in Equation 3 below. .

(Equation 3) GMF = Z1 * N1 * N2 [Hz]

The processor 710 may receive rotation speed information of the motor 131 from an inverter (not shown) that outputs AC power to the motor 131 . Information on the number of teeth of the first gear 136 and the number of teeth of the second gear 137 may be previously stored in the storage unit 720 .

Referring to (a) of FIG. 6 , the processor 710 of the controller 700 converts the displacement information or the current signal obtained when the motor 131 is in a normal operating state into frequency domain information using FFT, and converts The value at the gear meshing frequency can be set as a reference value in the frequency domain information.

The transformed frequency domain information may include information having various amplitudes at a plurality of frequencies. The processor 710 may set the amplitude P1 corresponding to the gear meshing frequency f1 [Hz] as a reference value.

Meanwhile, the processor 710 may integrate information belonging to a frequency domain within a predetermined frequency range based on the gear meshing frequency from the converted frequency domain information and set it as a reference value. For example, when the frequency domain of a [Hz] is set as the domain for setting the reference value, the processor 710 integrates amplitude information corresponding to the frequency domain f1+a [Hz] from f1-a [Hz] Alternatively, it can be averaged and set as a reference value.

On the other hand, when the motor 131 is in a normal operating state, the processor 710 acquires the displacement information or the current signal a plurality of times, converts it into frequency domain information using FFT, and averages the converted values as a reference value. can be set. The set reference value may be stored in the storage unit 720 .

Referring to (b) of FIG. 6 , the processor 710 obtains displacement information measured by the gap sensor 150 or a current signal of the motor bearing 141 when the motor 131 rotates and uses the FFT to obtain the frequency. It can be converted into area information. The processor 710 may compare the amplitude P2 corresponding to the gear meshing frequency f1 among the converted information with a preset reference value P1.

Meanwhile, the processor 710 may integrate information belonging to a frequency domain within a predetermined frequency range based on the gear meshing frequency in the converted frequency domain information and compare it with a reference value. For example, the processor 710 integrates or averages amplitude information corresponding to the frequency domain f1-a [Hz] to f1+a [Hz] in the same frequency range used for setting the reference value to compare it with the reference value P1. can

The processor 710 may determine that abnormal vibration has occurred in the first gear 136 or the second gear 137 when P2 is greater or less than the preset reference value P1 by a certain amount. For example, the processor 710 controls the display to display caution alarm information on a display (not shown) included in the compressor 100 or the refrigerator 2 when P2 is greater than or less than the first value b or more than P1. can do.

Meanwhile, the processor 710 may further include a communication unit (not shown), and may transmit caution alarm information to an external device through the communication unit so that the caution alarm information is displayed through a display provided in the external device.

Meanwhile, when P2 is greater than or smaller than the second value c than P1, the processor 710 may control the display to display warning and alarm information on the display. The second value c is a value greater than the first value b. In addition, the processor 710 may stop the operation of the compressor 100 or the operation of the refrigerator 2 together with the warning alarm information display.

The processor 710 may control the display to stop the operation of the compressor 100 or the refrigerator 2 and display information guiding the gearbox inspection on the display. Therefore, the manager who manages the refrigerator 2 checks the inspection guide information displayed on the display, and performs a gearbox inspection including the first gear 136 and the second gear 137, and the gearbox is damaged. In this case, the gearbox can be serviced.

Meanwhile, the controller 700 may further include a user interface (not shown) through which an administrator can input information through the controller 700 . Alternatively, the controller 700 may be configured to be connected to an external user interface. The user interface may include a display, and may include various types of known input devices such as a touch screen, a keyboard, a mouse, and the like. Accordingly, the administrator may input information about the result of performing the gearbox inspection through the user interface.

Referring to (a) and (b) of Figure 7, the processor 710 of the controller 700, when P2 is greater than the second value c than P1, it is possible to check the result of performing the gearbox inspection input through the user interface. there is. When the gear box inspection result is abnormal, the processor 710 may not change the reference value P1. When the gearbox test result is normal, the processor 710 may determine that P2 is also in the normal region and change the reference value P1 to P1'.

For example, P1' may have the same value as P2. Alternatively, P1' may be a value obtained by averaging P1 and P2, and may be an average value of all measurement values within a predetermined period based on a time point at which P2 is measured.

Alternatively, the processor 710 may change the first value b and the second value c to b' and c', respectively, without changing the reference value P1. For example, b' may be a value greater than b, and c' may be a value greater than c.

Meanwhile, the processor 710 may store information about the time point at which the reference value P1 is set in the storage unit 720 . When a predetermined period of time has elapsed from the point in time when the reference value P1 is set, the processor 910 may reset the reference value P1 by updating it. For example, P1 may be changed to be equal to the average value of all measured values within a predetermined period based on the current time point.

8 is a flowchart illustrating a method for determining whether abnormal vibration occurs in the compressor 100 according to an embodiment of the present invention.

Referring to the drawings, the processor 710 of the controller 700 calculates a gear meshing frequency according to the rotation speed of the motor 131 of the compressor 100 (S801).

The processor 710 obtains the displacement information of the first rotation shaft 132 measured by the gap sensor 150 or the current signal of the motor bearing 141 ( S802 ).

The processor 710 converts the obtained displacement information or current signal into frequency domain information using FFT. The amplitude value corresponding to the gear meshing frequency among the converted information is compared with a reference value (S803).

When the amplitude value corresponding to the gear meshing frequency is not different from the reference value by more than a certain amount, the processor 710 calculates the gear meshing frequency while continuously receiving the rotation speed information of the motor 131, and if there is a difference of more than a certain amount It is determined that abnormal vibration has occurred in the gear and an alarm is output (S805).

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and it is common in the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Various modifications may be made by those having the knowledge of, of course, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

Claims (11)

motor;
a first rotating shaft coupled to the motor to rotate;
a first gear formed on the first rotating shaft;
a second rotating shaft coupled to at least one impeller to rotate;
a second gear formed on the second rotation shaft and engaged with the first gear; and
Calculate the gear meshing frequencies of the first gear and the second gear, determine whether abnormal vibration occurs between the first gear and the second gear at the calculated gear meshing frequency, and when it is determined that the abnormal vibration occurs A compressor comprising a controller controlling to output an alarm. According to claim 1,
The controller is
Receiving rotation speed information of the motor from an inverter that outputs AC power to the motor,
Compressor, characterized in that for calculating the gear meshing frequency using the rotation speed of the motor, the number of teeth of the first gear, and the number of teeth of the second gear. According to claim 1,
Further comprising a gap sensor for detecting the distance to the first rotation axis,
The controller is
Compressor, characterized in that it is determined whether the abnormal vibration occurs based on the displacement information measured by the gap sensor. According to claim 1,
Further comprising at least one or more motor bearings limiting the first rotation shaft to vibrate in the vertical direction of the shaft,
The controller is
Compressor, characterized in that it is determined whether the abnormal vibration is generated based on the current signal of the motor bearing. According to claim 1,
The controller is
When the motor rotates, the displacement information measured by the gap sensor or the current signal of the motor bearing is acquired and converted into frequency domain information,
Compressor, characterized in that by comparing the converted displacement information or the converted current signal at the gear meshing frequency with a preset reference value, and determining that the abnormal vibration has occurred when it is greater or less than a predetermined reference value . 6. The method of claim 5,
The controller is
Converting the displacement information or the current signal obtained when the motor is in a normal operating state into frequency domain information,
Compressor, characterized in that for setting the converted displacement information or the converted current signal at the gear meshing frequency as the reference value. 7. The method of claim 6,
The controller is
When the motor is in a normal operating state, the displacement information or the current signal is acquired a plurality of times and averaged to set the reference value. 6. The method of claim 5,
further comprising a display,
The controller is
When the converted displacement information or the converted current signal in the gear meshing frequency is greater than or less than a first value than the reference value, the compressor is characterized in that it controls to display a caution alarm on the display. 9. The method of claim 8,
The controller is
When the converted displacement information or the converted current signal at the gear meshing frequency is greater than or less than a second value or less than the reference value, control to display a warning alarm on the display and stop the operation of the compressor,
and the second value is greater than the first value. 10. The method of claim 9,
The controller is
When stopping the operation of the compressor, control to display the storage box inspection guide information on the display,
Compressor, characterized in that the reset by updating the reference value when the test result of the gear box is normal or when more than a predetermined time has elapsed after setting the reference value. condenser;
evaporator; and
Compressor; Including,
The compressor is
motor;
a first rotating shaft coupled to the motor to rotate;
a first gear formed on the first rotating shaft;
a second rotating shaft coupled to at least one impeller to rotate;
a second gear formed on the second rotation shaft and engaged with the first gear; and
Calculating the gear meshing frequencies of the first gear and the second gear, determining whether abnormal vibration occurs in the first gear or the second gear from the calculated gear meshing frequency, and an alarm when it is determined that abnormal vibration occurs Refrigerator, characterized in that it comprises a controller for controlling to output.

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