Three-phase compressor with built-in double protectors

Abstract

The utility model discloses a three-phase compressor with built-in double protectors. The three-phase compressor comprises a compressor motor, a first protector and a second protector, the compressor motor comprises a first phase end, a second phase end, a third phase end, a first winding, a second winding and a third winding, the first winding is connected with the first phase end, the second winding is connected with the second phase end, the third winding is connected with the third phase end, and the first winding is connected with the second winding. The first winding, the second winding and the third winding are connected to a neutral point; the first protector and the second protector are arranged in the compressor motor, the first protector is connected with the first winding, the second protector is connected with the second winding, and when the first protector or the second protector is overheated, the first protector or the second protector respectively forms an open circuit.

Description

Technical Field

[0001] A three-phase compressor, especially a three-phase compressor with built-in double protectors. Background Art

[0002] Please see Figure 4 As shown, a known three-phase compressor 100 may be provided with an external protection circuit, which includes a controller 101, an electromagnetic switch 102, a thermal protector 103 and a timer 104. The electromagnetic switch 102 is provided in the controller 101 and is electrically connected to the thermal protector 103 and the timer 104. The controller 101 controls whether a power supply 200 supplies power to the three-phase compressor 100 by turning on and off the electromagnetic switch 102. In order to prevent the three-phase compressor 100 from being damaged due to motor stalling or power shortage, the thermal protector 103 is usually provided on the casing of the three-phase compressor 100 to sense whether the casing temperature of the three-phase compressor 100 is too high.

[0003] When the shell temperature of the three-phase compressor 100 is too high, the metal sheet inside the thermal protector 103 will be deformed by the temperature and cause a short circuit in the thermal protector 103, and the electromagnetic switch 102 in the controller 101 will be powered off, thereby disconnecting a power supply path for the power supply 200 to supply power to the three-phase compressor 100 through the controller 101, thereby preventing the three-phase compressor 100 from burning due to abnormal operation.

[0004] Since the internal components of the known thermal protector 103 are not protected by inert gas and are not completely sealed, arc leakage is prone to occur at the contacts of the internal components of the thermal protector 103, resulting in combustion or explosion. Based on safety considerations, the thermal protector 103 cannot be set inside the three-phase compressor 100, but must be set on the outer casing of the three-phase compressor 100.

[0005] However, it takes a long time for the heat source generated by the internal operation of the three-phase compressor 100 to be conducted and convected to the outer casing, and it is easily affected by the environment. As a result, when the thermal protector 103 is triggered by high temperature, the three-phase compressor 100 is often damaged long ago, making it difficult to respond to the abnormal condition of the three-phase compressor 100 in real time, resulting in poor sensitivity and reliability of the known protection mechanism.

[0006] On the other hand, the electromagnetic switch 102 in the controller 101 cannot be turned on automatically, and the timer 104 needs to be set additionally. After the electromagnetic switch 102 is turned off, the timer 104 controls the electromagnetic switch 102 to be turned on again after a waiting time, so that the power supply 200 can supply power to the three-phase compressor 100 again. The existing electromagnetic switch 102 and the thermal protector 103 usually need 10 to 30 minutes to resume operation, which is easy to affect the real-time performance of the subsequent resumption of use of the three-phase compressor 100. In addition, the number of components in the protection circuit connected to the three-phase compressor 100 is relatively large, and the required setting cost is also relatively high.

[0007] Please see Figure 5 As shown, a known three-phase protector 300 includes a first pin 310, a second pin 320, a third pin 330 and a thermal spring 340, wherein the first pin 310 is connected to a first contact 341 of the thermal spring 340 via a pin contact 311, the second pin 320 is connected to a second contact 342 of the thermal spring 340 via a pin contact 321, and the third pin 330 is directly connected to the thermal spring 340, so that the first pin 310, the second pin 320 and the third pin 330 are electrically connected to each other via the thermal spring 340. When the thermal spring 340 is deformed by temperature triggering, the thermal spring 340 bends, so that the first contact 341 of the thermal spring 340 is disconnected from the pin contact 311 of the first pin 310, and the second contact 342 of the thermal spring 340 is disconnected from the pin contact 321 of the second pin 320, so that the first pin 310, the second pin 320 and the third pin 330 are disconnected from each other.

[0008] However, in order to allow the thermal spring 340 to bend and deform at both the first contact 341 and the second contact 342, the three-phase protector 300 has a larger overall size, and the volume and cost of the three-phase protector 300 cannot be further reduced. In addition, due to the large size of the thermal spring 340, a higher temperature is required to trigger the thermal spring 340 to deform. Therefore, the three-phase protector 300 can only be used in large-scale electromechanical equipment with an operating current of more than 18 amperes (A), and cannot be used in a three-phase compressor 100 that generally uses AC power.

[0009] It can be seen that the protection mechanism of the existing three-phase compressor 100 still has room and necessity for further improvement. Utility Model Content

[0010] In view of this, the present invention provides a three-phase compressor with a built-in double protector, which provides protection for the three-phase compressor through two built-in protectors, so as to improve the real-time and reliability of the protection of the three-phase compressor and reduce the overall setting cost.

[0011] To achieve the above-mentioned purpose, the novel three-phase compressor with built-in double protectors comprises:

[0012] A compressor motor, comprising a first phase end, a second phase end, a third phase end, a first winding, a second winding and a third winding, wherein the first winding is connected to the first phase end, the second winding is connected to the second phase end, the third winding is connected to the third phase end, and the first winding, the second winding and the third winding are connected in a Y-type connection, and the first winding, the second winding and the third winding are connected to a neutral point of the compressor motor;

[0013] A first protector is disposed in the compressor motor and connected to the first winding, and when the first protector is overheated, the first protector forms a circuit break;

[0014] The second protector is arranged in the compressor motor and connected to the second winding. When the second protector is overheated, the second protector forms a circuit break.

[0015] In the three-phase compressor with built-in dual protectors of the novel type, the two protectors are arranged inside the compressor motor to provide a three-phase protection function for the compressor motor, so that when the compressor motor abnormally causes the internal temperature to rise, a circuit can be broken in real time to prevent the compressor motor from continuing to operate abnormally, thereby protecting the compressor motor. Compared with the known thermal protector, the two protectors are arranged in the compressor motor, which can provide a protection function more timely and reliably due to the temperature change of the compressor motor, and the novel type does not need to set up additional components such as timers and electromagnetic switches, which helps to reduce the installation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 : A circuit diagram of the first embodiment of the three-phase compressor with built-in double protectors of the present invention.

[0017] Figure 2 : A circuit diagram of the second embodiment of the three-phase compressor with built-in double protectors of the present invention.

[0018] Figure 3 : A partial cross-sectional view of the protector in this novel embodiment.

[0019] Figure 4 : Circuit block diagram of a known three-phase compressor and its protection circuit.

[0020] Figure 5 : Partial cross-sectional view of a known three-phase protector. DETAILED DESCRIPTION

[0021] Please see Figure 1 and Figure 2 As shown, the novel three-phase compressor 1 with built-in dual protectors 11 includes a compressor motor 10 and two protectors 11 , and the three-phase compressor 1 is powered by a three-phase power source provided by a power supply 2 . The compressor motor 10 includes a first phase terminal R, a second phase terminal S, a third phase terminal T, a first winding U, a second winding V and a third winding W, a power end of the first winding U is connected to the first phase terminal R, a power end of the second winding V is connected to the second phase terminal S, a power end of the third winding W is connected to the third phase terminal T, and the first winding U, the second winding V and the third winding W are connected in a Y-type connection, so that a load end of the first winding U, a load end of the second winding V and a load end of the third winding W are connected to a neutral point N of the compressor motor 10, wherein the neutral point N can be further connected to a load by a neutral lead, and the first winding U is connected to the power supply 2 through the first phase terminal R, the second winding V is connected to the second phase terminal S, and the third winding W is connected to the third phase terminal T.

[0022] When the power supply 2 provides the three-phase power to the compressor motor 10, the current of the three-phase power will flow into the first winding U, the second winding V and the third winding W from the first phase end R, the second phase end S and the third phase end T respectively, and when the current flows through the first winding U, the second winding V and the third winding W, a current magnetic effect is generated, thereby forming a rotating magnetic field to make the compressor motor 10 operate.

[0023] For example, since the phase angle difference between the first winding U, the second winding V and the third winding W is 120 degrees, the current of the three-phase power supply can first flow into the first winding U from the first phase end R; when switching phases, the current of the three-phase power supply can be changed to flow into the second winding V from the second phase end S; and when switching phases again, the current of the three-phase power supply can be changed to flow into the third winding W from the third phase end T, and then the first winding U, the second winding V and the third winding W are respectively generated with different current flows to rotate the rotor in the compressor motor 10. The above briefly describes the operation process of the compressor motor 10, but the switching and operation mode of the compressor motor 10 are not limited to this embodiment.

[0024] The two protectors 11 are built into the compressor motor 10, and the two protectors 11 are respectively connected to one of the first winding U, the second winding V and the third winding W, that is, two windings of the first winding U, the second winding V and the third winding W are respectively connected to a protector 11. When the two protectors 11 are overheated, the two protectors 11 form a circuit breaker, wherein the two protectors 11 can be a single-phase protector respectively. Figure 1 and Figure 2 In the embodiment, the two protectors 11 are a first protector 11A and a second protector 11B, the first protector 11A is electrically connected to the first winding U, and the second protector 11B is electrically connected to the second winding V, but the first protector 11A may also be electrically connected to the first winding U, and the second protector 11B is electrically connected to the third winding W; or; the first protector 11A is electrically connected to the second winding V, and the second protector 11B is electrically connected to the third winding W, which is not limited to this embodiment. Figure 1 and Figure 2 The embodiment only illustrates that two windings among the first winding U, the second winding V and the third winding W are respectively connected to a protector 11, and does not limit the phases to which the two protectors 11 are connected.

[0025] exist Figure 1 In the embodiment of the present invention, the first protector 11A is electrically connected between the first winding U and the first phase terminal R, and the second protector 11B is electrically connected between the second winding V and the second phase terminal S. Figure 2 In the embodiment, the first protector 11A is electrically connected between the first winding U and the neutral point N, and the second protector 11B is electrically connected between the second winding V and the neutral point N, and the first protector 11A and the second protector 11B provide three-phase protection for the compressor motor 10.

[0026] In addition, in a preferred embodiment, the first protector 11A is electrically connected between the first winding U and the first phase end R, and the second protector 11B is electrically connected between the second winding V and the neutral point N; or, the first protector 11A is electrically connected between the first winding U and the neutral point N, and the second protector 11B is electrically connected between the second winding V and the second phase end S.

[0027] Please see Figure 3As shown, each of the protectors 11 in the present invention may include an insulating shell 12, a sealed inner shell 13, a first pin 14, a second pin 15 and a thermal spring 16, the insulating shell 12 is covered on the outside of the sealed inner shell 13, a first pin contact 141 of the first pin 14, a second pin contact 142 of the first pin 14, a pin contact 151 of the second pin 15 and the thermal spring 16 are arranged in the sealed inner shell 13 to isolate the first pin contact 141 of the first pin 14, the second pin contact 142 of the first pin 14, the pin contact 151 of the second pin 15 and the thermal spring 16 from the external environment to prevent the internal components from being affected by the external environment, and the sealed inner shell 13 is filled with inert gas to prevent arcing, burning and the like from occurring in the sealed inner shell 13.

[0028] The first pin contact 141 of the first pin 14 is connected and conducted with the second pin contact 142 through the sealed inner shell 13; one end of the thermal spring 16 is fixedly connected with the second pin contact 142 of the first pin 14, and the other end of the thermal spring 16 is in contact with the pin contact 151 of the second pin 15, and the first pin 14 and the second pin 15 are connected and conducted through the thermal spring 16.

[0029] The thermal spring 16 will be deformed and bent when heated. Since one end of the thermal spring 16 is fixed to the second pin contact 142 of the first pin 14, when the two protectors 11 are overheated, the thermal spring 16 in the two protectors 11 will be bent by the heat, and the other end of the thermal spring 16 will jump out of the pin contact 151 of the second pin 15, so that a short circuit is formed between the thermal spring 16 and the second pin 15, thereby forming a short circuit between the first pin 14 and the second pin 15. It only takes 10 to 30 seconds for the thermal spring 16 to return to a normal state after deformation, which helps to quickly restart the compressor motor 10.

[0030] When the first protector 11A is Figure 1When connected between the first phase terminal R and the first winding U, the first pin 14 of the first protector 11A can be connected to the first phase terminal R, and the second pin 15 of the first protector 11A is connected to the first winding U. If the current flowing through the first winding U is too high, the thermal spring 16 in the first protector 11A is deformed due to heat, so that a circuit is formed between the first pin 14 and the second pin 15 in the first protector 11A, thereby causing a circuit break between the first phase terminal R and the first winding U, thereby preventing abnormal large current from continuing to flow from the first winding U into the compressor motor 10, thereby avoiding damage to the compressor motor 10. It should be noted that the first protector 11A can also be connected to the first winding U by the first pin 14, and the second pin 15 of the first protector 11A is connected to the first phase terminal R, without affecting the operation of the first protector 11A.

[0031] Similarly, the second protector 11B is as follows Figure 1 When connected between the second phase terminal S and the second winding V, the first pin 14 of the second protector 11B can be connected to the second phase terminal S, and the second pin 15 of the second protector 11B is connected to the second winding V. If the current flowing through the second winding V is too high, the thermal spring 16 in the second protector 11B is deformed due to heat, so that a circuit is formed between the first pin 14 and the second pin 15 of the second protector 11B, thereby causing a circuit break between the second phase terminal S and the second winding V.

[0032] When the first protector 11A is Figure 2 When connected between the first winding U and the neutral point N, the first pin 14 of the first protector 11A can be connected to the first winding U, and the second pin 15 of the first protector 11A is connected to the neutral point N. If the current flowing through the first winding U is too high, the thermal spring 16 in the first protector 11A is deformed due to heat, so that a short circuit is formed between the first pin 14 and the second pin 15 in the first protector 11A, thereby causing a short circuit between the first winding U and the neutral point N.

[0033] Similarly, the second protector 11B is as follows Figure 1When connected between the second winding V and the neutral point N, the first pin 14 of the second protector 11B can be connected to the second winding V, and the second pin 15 of the second protector 11B is connected to the neutral point N. If the current flowing through the second winding V is too high, the thermal spring 16 in the second protector 11B is deformed due to heat, so that a short circuit is formed between the first pin 14 and the second pin 15 in the second protector 11B, thereby causing a short circuit between the second winding V and the neutral point N.

[0034] When the three-phase power supply supplies power to the compressor motor 10, the current will flow from one of the first winding U, the second winding V and the third winding W, and then flow to the other winding. Therefore, only two protectors 11 need to be set in the first winding U, the second winding V and the third winding W to cover various phase changes and abnormal conditions of the first winding U, the second winding V and the third winding W.

[0035] For example, when the first phase end R is under-phase, the current on the first winding U connected to the first phase end R is zero, and the operation of the compressor motor 10 needs to be completed by the remaining second winding V and the third winding W, so that the current flowing through the second winding V and the third winding W is too high, which may easily cause the internal temperature of the compressor motor 10 to be too high and burn out. The thermal spring 16 of the second protector 11B connected to the second winding V will be deformed due to heat, causing the second protector 11B to be short-circuited.

[0036] When the second phase end S is under-phase, the current on the second winding V connected to the second phase end S is zero, and the operation of the compressor motor 10 needs to be completed by the remaining first winding U and the third winding W, so that the current flowing through the first winding U and the third winding W is too high, and the thermal spring 16 of the first protector 11A connected to the first winding U will be deformed due to heat, causing the first protector 11A to be short-circuited.

[0037] When the third phase terminal T is under-phase, the current on the third winding W connected to the third phase terminal T is zero, and the operation of the compressor motor 10 needs to be completed by the remaining first winding U and second winding V, so that the current flowing through the first winding U and the second winding V is too high, and the thermal spring piece 16 of the first protector 11A connected to the first winding U and the thermal spring piece 16 of the second protector 11B connected to the second winding V will both be deformed due to heat, causing the first protector 11A and the second protector 11B to be disconnected respectively.

[0038] It should be noted that phase loss is only one of the situations that may cause abnormal operation of the compressor motor 10. When the three-phase power supply is unbalanced, the voltage of the three-phase power supply is too high or too low, a load device connected to the compressor motor 10 is abnormal, the winding is open or damaged, the winding is short-circuited, the circuit pins are loose, or a mechanical failure occurs, the compressor motor 10 may overheat due to increased current or abnormal operation. The two protectors 11 can form a circuit break in real time according to the temperature change inside the compressor motor 10, thereby providing a protection function for the compressor motor 10.

[0039] In a preferred embodiment, the three-phase compressor 1 of the present invention is applied to a refrigeration device, and the three-phase compressor 1 further includes a pressure switch, which is electrically connected to the neutral point N through a neutral line. The pressure switch is used to sense an ambient pressure. When the ambient pressure is greater than a default value, the pressure switch forms an open circuit. For example, when the ambient pressure of the refrigeration device increases due to refrigerant leakage, in order to avoid damage to the human body and the device caused by the refrigerant leakage, and to prevent the protectors 11 from being unable to accurately sense temperature changes due to refrigerant leakage to provide protection for the compressor motor 10 in real time, when the pressure switch senses that the ambient pressure is greater than a default value, the pressure switch forms an open circuit to stop the refrigeration device from operating without continuously leaking refrigerant.

[0040] In summary, the three-phase compressor 1 with built-in dual protectors 11 provides a three-phase protection function for the compressor motor 10 through the two protectors 11 disposed inside the compressor motor 10. When the compressor motor 10 is abnormal and causes the internal temperature to rise, the two protectors 11 can form a circuit break in real time to prevent the compressor motor 10 from continuing to operate abnormally, so as to protect the compressor motor 10. Compared with the known thermal protectors, the internal components of the two protectors 11 are disposed in the sealed inner shell 13, which is safer and does not need to worry about the situation where the components burn due to arc leakage. The two protectors 11 are disposed inside the compressor motor 10, which helps to take protective actions more timely due to the temperature change of the compressor motor 10, avoiding the situation where the compressor is often damaged when the known thermal protector is triggered by high temperature. The two protectors 11 are directly connected to the winding inside the compressor motor 10, and do not need to set up additional components such as timers and electromagnetic switches, which helps to reduce the installation cost.

[0041] On the other hand, compared with the known three-phase protector, the two protectors 11 in the present invention have one end of the thermal spring piece 16 of the two protectors 11 as a fixed structure, and the thermal spring piece 16 of the two protectors 11 only needs to be slightly deformed to form a short circuit in the two protectors 11. Therefore, the size of the thermal spring piece 16 in the two protectors 11 is smaller than that of the thermal spring piece of the known three-phase protector that requires deformation of both ends at the same time. And because the size of the thermal spring piece 16 in the two protectors 11 is small, it does not require excessive temperature changes to trigger the two protectors 11 to produce a short circuit, so that the two protectors 11 can be used in small electromechanical devices that use AC power and have an operating current of 0.5A to 15A, that is, the two protectors 11 can be used on three-phase compressors 1 that generally use AC power on the market.

Claims

1. A three-phase compressor with built-in double protectors, characterized in that: Contains: A compressor motor, comprising a first phase end, a second phase end, a third phase end, a first winding, a second winding and a third winding, wherein the first winding is connected to the first phase end, the second winding is connected to the second phase end, the third winding is connected to the third phase end, and the first winding, the second winding and the third winding are connected in a Y-type connection, and the first winding, the second winding and the third winding are connected to a neutral point of the compressor motor; A first protector is disposed in the compressor motor and connected to the first winding, and when the first protector is overheated, the first protector forms a circuit break; The second protector is arranged in the compressor motor and connected to the second winding. When the second protector is overheated, the second protector forms a circuit break.

2. The three-phase compressor with built-in double protectors according to claim 1, characterized in that: The first protector is connected between the first phase end and the first winding; the second protector is connected between the second phase end and the second winding.

3. The three-phase compressor with built-in double protectors according to claim 1, characterized in that: The first protector is connected between the first winding and the neutral point; the second protector is connected between the second winding and the neutral point.

4. The three-phase compressor with built-in double protectors according to claim 1, characterized in that: The first protector is connected between the first phase end and the first winding; the second protector is connected between the second winding and the neutral point.

5. The three-phase compressor with built-in double protectors as claimed in claim 1, characterized in that: The first protector is connected between the first winding and the neutral point; the second protector is connected between the second phase end and the second winding.

6. The three-phase compressor with built-in double protectors according to claim 1, characterized in that: The first protector and the second protector respectively include a first pin, a second pin and a thermal spring, and the thermal spring is connected between the first pin and the second pin; When the first protector and the second protector are overheated, the thermally sensitive springs in the first protector and the second protector are deformed by the heat and form a short circuit between the first pin and the second pin.

7. The three-phase compressor with built-in double protectors according to claim 1, characterized in that: The first protector and the second protector are respectively a single-phase protector.

8. The three-phase compressor with built-in double protectors according to claim 1, characterized in that: Further included are: A pressure switch is connected to the neutral point of the compressor motor. When the pressure switch senses that an ambient pressure is greater than a default value, the pressure switch forms an open circuit.

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