CN219875402U - Grounding device for preventing motor from electric leakage and electric equipment - Google Patents
Grounding device for preventing motor from electric leakage and electric equipment Download PDFInfo
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- CN219875402U CN219875402U CN202320846438.6U CN202320846438U CN219875402U CN 219875402 U CN219875402 U CN 219875402U CN 202320846438 U CN202320846438 U CN 202320846438U CN 219875402 U CN219875402 U CN 219875402U
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- 239000003990 capacitor Substances 0.000 claims description 36
- 230000001681 protective effect Effects 0.000 claims description 3
- 230000002265 prevention Effects 0.000 claims 2
- 238000010586 diagram Methods 0.000 description 7
- 230000002829 reductive effect Effects 0.000 description 7
- 230000002401 inhibitory effect Effects 0.000 description 4
- 238000001914 filtration Methods 0.000 description 3
- 238000009434 installation Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000000670 limiting effect Effects 0.000 description 2
- 230000000386 athletic effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
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Abstract
The utility model relates to the technical field of electric equipment, in particular to a grounding device for preventing motor leakage and electric equipment. The grounding device for preventing the motor from electric leakage comprises a circuit board and a resonance filter circuit arranged on the circuit board, wherein a first end of the resonance filter circuit is used for being connected with a shell of the motor, a second end of the resonance filter circuit is used for being connected with the ground, and the resonance filter circuit filters leakage current flowing out of the shell of the motor; during operation of the motor, the equivalent capacitance between the stator and the casing of the motor generates a large common mode voltage, so that common mode current is generated, and strong electromagnetic interference is generated, and the resonance filter circuit can also suppress the electromagnetic interference generated by the motor within a certain range. The grounding device for preventing motor leakage can filter leakage current flowing out of the motor shell, so that leakage current generated during motor operation is prevented from directly flowing to electric equipment to cause that the whole machine leakage current exceeds standard, and electromagnetic interference generated during motor operation can be suppressed.
Description
Technical Field
The utility model relates to the technical field of electric equipment, in particular to a grounding device for preventing motor leakage and electric equipment.
Background
Some electric devices, such as sports equipment, generally use a motor with relatively high power. In the using process of the motor, a PWM pulse signal is generally adopted to drive the motor to operate, when the PWM pulse signal performs switching action, the pulse characteristic of the PWM pulse signal can cause the inverter to output high voltage change rate and unbalanced instantaneous voltage, and at the moment, the equivalent capacitance between the stator and the shell of the motor can generate large common mode voltage so as to generate common mode current, and meanwhile, strong electromagnetic interference can be generated to endanger the reliable operation of surrounding equipment.
Under the normal condition, in order to solve the problem of motor electromagnetic interference, the motor shell can be directly connected with the shell of the electric equipment, but the leakage current generated during motor operation can directly flow to the electric equipment, so that the leakage current of the electric equipment is large and even exceeds the standard, and great potential safety hazard is brought.
Disclosure of Invention
Based on the above, the utility model provides the grounding device for preventing the motor from electric leakage and the electric equipment, and the grounding device for preventing the motor from electric leakage can filter the electric leakage current flowing out of the motor shell, so that the electric leakage current generated when the motor operates can be prevented from directly flowing to the electric equipment to cause the whole machine electric leakage current to exceed the standard, the safety level of the electric equipment is improved when the electric equipment is used, and meanwhile, electromagnetic interference signals generated when the motor operates can be filtered to play a role in inhibiting.
According to a first aspect of the present utility model, there is provided a grounding device for preventing leakage of a motor, applied to electric equipment, the electric equipment including a motor;
the grounding device for preventing the motor from leaking electricity comprises a circuit board and a resonance filter circuit arranged on the circuit board, wherein a first end of the resonance filter circuit is used for being connected with a shell of the motor, a second end of the resonance filter circuit is used for being connected with the ground, and the resonance filter circuit filters leakage current flowing out of the shell of the motor and suppresses electromagnetic interference generated by the motor.
According to a second aspect of the present utility model, there is provided an electric device, including a control main board, a motor connected to the control main board, and a motor leakage preventing grounding device according to the above embodiment, wherein a first end of the motor leakage preventing grounding device is connected to a casing of the motor, and a second end of the motor leakage preventing grounding device is connected to the ground.
In the embodiment of the utility model, the grounding device is arranged between the shell of the motor of the electric equipment and the ground, and the leakage current flowing out of the shell of the motor can be filtered through the grounding device, so that the leakage current generated when the motor operates is prevented from directly flowing to the electric equipment to cause the whole machine leakage current to exceed the standard, the safety level of the electric equipment is improved, and meanwhile, the electromagnetic interference signal generated when the motor operates is filtered to play a role in inhibiting, and the harm of electromagnetic interference is reduced.
For a better understanding and implementation, the technical solution of the present utility model is described in detail below with reference to the accompanying drawings.
Drawings
Fig. 1 is a schematic connection diagram of a grounding device for preventing motor leakage according to an embodiment of the present utility model;
fig. 2 is a schematic structural diagram of a grounding device for preventing motor leakage according to an embodiment of the present utility model;
FIG. 3 is a schematic diagram illustrating the connection of a resonant filter circuit according to an embodiment of the present utility model;
fig. 4 is a schematic structural diagram of an electric device according to an embodiment of the present utility model.
Reference numerals in the drawings: 100. an electric device; 10. an electrical equipment shell; 20. a motor; 21. a housing; 22. an insulating member; 30. grounding device for preventing motor leakage; 31. a resonant filter circuit.
Detailed Description
The utility model is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the matters related to the present utility model are shown in the accompanying drawings.
It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.
Several specific examples are given below to describe the technical solution of the present utility model in detail. The following embodiments may be combined with each other, and some embodiments may not be repeated for the same or similar concepts or processes.
In the related art, during the operation of a motor for driving electric equipment by using a PWM pulse signal, a strong electromagnetic interference problem is usually generated due to the existence of a common mode voltage and a common mode current on the motor. In order to solve the problem of electromagnetic interference of a motor, a motor shell can be directly connected with a shell (referenced ground) of electric equipment, however, leakage current generated during motor operation can directly flow to the electric equipment, so that the leakage current of the whole machine is large and even exceeds standard, and great potential safety hazard is brought. Therefore, the reliability of the scheme of solving electromagnetic interference that meets the shell of motor casing and consumer is relatively poor, to this, some research personnel have thought to adopt the shield cover to solve motor electromagnetic interference, but because the motor is bulky, increase the weight increase that the shield cover can make whole equipment in the motor outside, inconvenient transport and installation, user experience is relatively poor to the shielding effect is unstable enough, can appear the condition of repeated interference, also can increase the manufacturing cost of complete machine equipment in addition.
Aiming at the related problems, the embodiment of the utility model provides a grounding device for preventing motor leakage and electric equipment, wherein the grounding device for preventing motor leakage can filter leakage current flowing out of a motor shell, so that the leakage current generated when a motor operates is prevented from directly flowing to the electric equipment to cause the whole machine leakage current to exceed the standard, the safety level of the electric equipment is improved, and electromagnetic interference signals generated when the motor operates can be filtered to play a role in inhibiting.
Various embodiments of the present utility model are described in detail below with reference to the attached drawing figures.
Referring to fig. 1 and fig. 2, fig. 1 is a schematic connection diagram of a grounding device for preventing motor leakage according to an embodiment of the utility model; fig. 2 is a schematic structural diagram of a grounding device for preventing motor leakage according to an embodiment of the present utility model.
The grounding device for preventing motor leakage is applied to electric equipment, and the electric equipment comprises an electric equipment shell 10, a control main board and a motor 20 connected with the control main board. The motor 20 may be a dc motor 20 with a high power.
The grounding device for preventing motor leakage comprises a circuit board and a resonance filter circuit 31 arranged on the circuit board, wherein a first end of the resonance filter circuit 31 is used for being connected with a shell 21 of the motor 20, and a second end of the resonance filter circuit 31 is used for being connected with the ground; the resonance filter circuit 31 filters the leakage current flowing out of the casing of the motor 20 to reduce the leakage current of the whole machine of the electric equipment.
During operation of the motor 20, the equivalent capacitance between the stator of the motor 20 and the housing 21 generates a large common mode voltage, thereby generating common mode currents, with the concomitant generation of strong electromagnetic interference, compromising the reliable operation of the surrounding equipment. The electromagnetic interference is a high-frequency noise with a frequency within a certain range, in this embodiment, the resonant filter circuit is an RC filter circuit composed of a resistor and a capacitor, where the resistor element is used to limit transient current, i.e. to suppress leakage current flowing out of the casing 21 of the motor 20, and the capacitor element is used to filter out the high-frequency noise and only transmit low-frequency components backward, so as to filter out electromagnetic interference signals generated during the operation of the motor 20, thereby achieving the purpose of suppressing electromagnetic interference.
The second end of the resonant filter circuit 31 may be connected to the ground through the housing of the electric device 100, and the leakage current becomes weak after the filtration of the resonant filter circuit 31, that is, the leakage current of the whole electric device is reduced, and the weak leakage current after the filtration is led to the ground. The high-frequency noise generated by the motor operation after the filtering of the resonance filter circuit 31 is filtered, so as to achieve the purpose of inhibiting electromagnetic interference.
In the technical scheme of the embodiment, the grounding device is arranged between the shell of the motor of the electric equipment and the ground, and the leakage current flowing out of the shell of the motor can be filtered through the grounding device, so that the leakage current generated during the operation of the motor is prevented from directly flowing onto the electric equipment to cause the exceeding of the leakage current of the whole machine, the safety level of the electric equipment during the use is improved, and meanwhile, the electromagnetic interference generated by the motor is suppressed, and the harm of the electromagnetic interference is reduced.
It should be noted that: the motor 20 is a main operation component on the electric equipment, and in order to ensure the safety of the electric equipment in the use process, each component and the whole machine on the electric equipment are required to meet certain safety requirements, so that the specifications of each electronic element on the resonance filter circuit 31 are required to be matched with the preset safety requirements of the electric equipment.
In an alternative embodiment, referring to fig. 3, fig. 3 is a schematic diagram illustrating connection of a resonant filter circuit 31 according to an embodiment of the present utility model.
The resonant filter circuit 31 may include an RC filter circuit composed of a plurality of resistors and a plurality of capacitors, or a filter circuit composed of other components, and the specific form of the resonant filter circuit 31 is not limited in this embodiment.
The RC filter circuit may include a first capacitor C1, a second capacitor C2, and a first resistor R1; the second capacitor C2 and the first capacitor C1 are connected in parallel and then connected in series with the first resistor R1 between the shell of the motor and the shell of the electric equipment, and the RC filter circuit is connected with the ground through the shell of the electric equipment, so that leakage current or interference signals are led to the ground.
Optionally, the first end of the second capacitor C2 is connected to the first end of the first capacitor C1 and then connected to the housing of the electric device, the second end of the second capacitor C2 is connected to the second end of the first capacitor C1 and then connected to the first end of the first resistor R1, and the second end of the first resistor R1 is connected to the casing of the motor 20.
Optionally, the first end of the second capacitor C2 is connected with the first end of the first capacitor C1 and then connected with the casing of the motor 20, the second end of the second capacitor C2 is connected with the second end of the first capacitor C1 and then connected with the first end of the first resistor R1, and the second end of the first resistor R1 is connected with the casing of the electric equipment and is connected with the ground through the casing of the electric equipment. Optionally, if the housing of the electrical device is connected to the power socket, the ground may be connected to the ground through a ground terminal of the power socket.
Because the RC filter circuit is provided with the capacitor, the capacitor can isolate the direct current leakage current flowing out of the shell of the motor, and the resistor and the capacitor of the RC filter circuit can play a role in blocking the leakage current.
The total impedance of the RC filter circuit is determined by the performance of the resistor and the capacitor, and the total impedance changes along with the change of frequency. The RC filter circuit has turning frequency, and the turning frequency of the RC filter circuit is matched with the frequency of the driving current of the motor. For example, the turn frequency of the RC filter circuit is f 0 ＝1/2πR 1 C 1 When the frequency of the current driving signal input to the motor is greater than f 0 When the resistance of the whole RC filter circuit is basically unchanged, the total impedance of the RC filter circuit is equal to the resistance of the resistor; when the frequency of the current driving signal input to the motor is smaller than f 0 When the frequency of the alternating current is low, the capacitance of the capacitor is increased to a degree which can not be ignored compared with the resistance value of the resistor, and the high-frequency noise on the motor is filtered out in a resonance mode by adjusting the capacitance of the resistor and the capacitor at a specific frequency by utilizing the characteristics.
In other embodiments, the RC filter circuit may also use other resistor-capacitor combinations, which are not limited in this embodiment.
Optionally, the casing 21 of the motor 20 is further sleeved with an insulating member 22, the insulating member 22 is disposed between the casing 21 of the motor and the housing 10 of the electric equipment, and the insulating member 22 is used for preventing leakage current from directly flowing to the housing 10 of the electric equipment, so that leakage current of the motor and interference signals generated by the operation of the motor can only be led to the housing 10 of the electric equipment through a resonant filter board path of the grounding device 30, and finally led to the ground through a grounding end of a power socket connected with the housing 10 of the electric equipment.
On the basis of the above embodiments, an equilibrium solution can also be achieved on the problems of leakage current and electromagnetic compatibility by adjusting the parameter values of the resistor and the capacitor. Namely, by configuring the resistance value and the capacitance value of the resistor, the RC filter circuit can filter the leakage current and high-frequency electromagnetic interference noise. In this embodiment, specific values of the resistance value and the capacitance value are not limited.
On the basis of the above embodiment, the circuit board is mounted on the control motherboard of the electric device, or the circuit board is the control motherboard of the electric device, and the resonance filter circuit 31 is mounted on the control motherboard.
When designing the control main board of the new electric equipment, the resonance filter circuit 31 can be directly arranged on the control main board, and when other components are welded and installed, the resonance filter circuit 31 can be directly installed on the control main board by adopting a conventional installation mode. If the assembled electric equipment needs to be maintained and upgraded, the resonant filter circuit 31 can be installed on a small circuit board, the circuit board is installed beside the control main board, one end of the circuit board is connected with the shell of the motor 20, and the other end of the circuit board is connected with the electric equipment shell 10.
On the basis of the above embodiment, if the circuit board is installed independently of the control main board of the electric equipment, the grounding device for preventing electric leakage of the motor further comprises a protective sleeve, and the protective sleeve wraps the circuit board, so that the installation and protection of the grounding device are facilitated.
In the technical scheme of the embodiment, the grounding device is arranged between the shell of the motor of the electric equipment and the shell of the electric equipment, and the leakage current flowing out of the shell of the motor can be filtered through the grounding device, so that the leakage current generated during the operation of the motor is prevented from directly flowing to the electric equipment to cause the whole machine leakage current to exceed the standard, the potential safety hazard of the electric equipment during the use is reduced, and meanwhile, the electromagnetic interference generated by the motor is suppressed, and the harm of the electromagnetic interference is reduced.
According to a second aspect of an embodiment of the present utility model, there is provided a powered device.
As shown in fig. 4, the electric device 100 may include a control main board, a motor 20 connected to the control main board, and a grounding device for preventing motor leakage according to the above embodiment, where a first end of the grounding device for preventing motor leakage is connected to a casing of the motor, and a second end of the grounding device for preventing motor leakage is connected to the ground, so that the leakage current and the motor interference signal are filtered and suppressed and then are led to the ground, so as to improve the safety of the whole electric device.
Alternatively, the second end of the grounding device for preventing motor leakage may be connected to the ground through the housing of the powered device.
In an alternative embodiment, powered device 100 is an athletic equipment or other powered device 100 that is powered by motor 20. The motor 20 of the electric device 100 is a dc motor 20 with larger power.
In the technical scheme of the electric equipment, the grounding device is arranged between the shell of the motor of the electric equipment and the shell of the electric equipment, and leakage current flowing out of the shell of the motor can be filtered through the grounding device, so that the leakage current generated during operation of the motor is prevented from directly flowing onto the electric equipment to cause the whole machine leakage current to exceed the standard, the potential safety hazard of the electric equipment during use is reduced, electromagnetic interference generated by the motor is suppressed, and the harm of the electromagnetic interference is reduced.
The foregoing examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model.
Claims (10)
1. The grounding device for preventing the motor from electric leakage is characterized by being applied to electric equipment, wherein the electric equipment comprises a motor;
the grounding device for preventing motor leakage comprises a circuit board and a resonance filter circuit arranged on the circuit board, wherein a first end of the resonance filter circuit is used for being connected with a shell of the motor, a second end of the resonance filter circuit is used for being connected with the ground, and the resonance filter circuit filters leakage current flowing out of the shell of the motor and suppresses electromagnetic interference generated by the motor.
2. The apparatus of claim 1, wherein the resonant filter circuit comprises an RC filter circuit comprising a plurality of resistors and a plurality of capacitors.
3. The apparatus of claim 2, wherein the RC filter circuit comprises a first capacitor, a second capacitor, and a first resistor;
the second capacitor and the first capacitor are connected in parallel and then connected with the first resistor in series between the shell of the motor and the shell of the electric equipment, and the RC filter circuit is connected with the ground through the shell of the electric equipment.
4. The apparatus of claim 3, wherein the first end of the second capacitor is connected to the first end of the first capacitor and then to the housing of the electrical device, the second end of the second capacitor is connected to the second end of the first capacitor and then to the first end of the first resistor, and the second end of the first resistor is connected to the housing of the electrical device; or,
the first end of the second capacitor is connected with the first end of the first capacitor and then connected with the shell of the motor, the second end of the second capacitor is connected with the second end of the first capacitor and then connected with the first end of the first resistor, and the second end of the first resistor is connected with the shell of the electric equipment.
5. The apparatus of claim 2, wherein the turn frequency of the RC filter circuit is matched to the frequency of the driving current of the motor.
6. The apparatus of claim 1, wherein the specification of each electronic component on the resonant filter circuit matches a predetermined safety specification of the electrical device.
7. The apparatus according to any one of claims 1 to 6, wherein the electric device further comprises a control main board, the circuit board is mounted on the control main board of the electric device, or,
the circuit board is a control main board of the electric equipment, and the resonance filter circuit is arranged on the control main board.
8. The motor leakage prevention earthing device according to any one of claims 1 to 6, further comprising a protective sleeve wrapping the circuit board.
9. The apparatus according to any one of claims 1 to 6, wherein the housing of the motor is further sleeved with an insulating member, the insulating member is disposed between the housing of the motor and the housing of the electric device, and the insulating member is used for preventing leakage current from directly flowing to the housing of the electric device.
10. An electric device is characterized by comprising a control main board, a motor connected with the control main board, and
the motor leakage prevention earthing device according to any one of claims 1 to 9,
the first end of the grounding device for preventing motor leakage is connected to the shell of the motor, and the second end of the grounding device for preventing motor leakage is connected to the ground.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320846438.6U CN219875402U (en) | 2023-04-14 | 2023-04-14 | Grounding device for preventing motor from electric leakage and electric equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320846438.6U CN219875402U (en) | 2023-04-14 | 2023-04-14 | Grounding device for preventing motor from electric leakage and electric equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219875402U true CN219875402U (en) | 2023-10-20 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320846438.6U Active CN219875402U (en) | 2023-04-14 | 2023-04-14 | Grounding device for preventing motor from electric leakage and electric equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219875402U (en) |
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2023
- 2023-04-14 CN CN202320846438.6U patent/CN219875402U/en active Active
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