An EMC filter device capable of suppressing commutator spark signals of an electric machine

Abstract

The utility model discloses a kind of EMC filter devices capable of inhibiting motor commutator spark signal, including motor, the motor has a commutator, characterized in that, the EMC filter device is a ring-shaped varistor, the ring-shaped varistor is installed on the commutator.The utility model is equipped with ring-shaped varistor on commutator, EMC emission interference problem is obviously improved, the long-term reform pain point is solved, the purpose of reaching most customer needs is realized.The ring-shaped varistor of the utility model effectively inhibits the emission interference problem caused by commutator spark from source: since commutator spark signal belongs to the voltage (du / dt) that is constantly changing, ring-shaped varistor can absorb this surge voltage, dissipate in air in the form of heat, so as to reduce spark disturbance to spread outward.

Description

Technical Field

[0001] This invention relates to the field of motor commutator technology, and particularly to an EMC filtering device that can suppress spark signals from a motor commutator. Background Technology

[0002] With the rapid development of the automotive industry, customers have increasingly higher requirements for related products, and automotive industry standards are placing higher demands on the electromagnetic compatibility (EMC) of products. In particular, the growing demand for new energy vehicles and intelligent connected vehicles in the automotive market urgently requires product function and technological upgrades to adapt to market demands, thus making the requirements for motor EMC standards increasingly stringent. In the future, with technological advancements and further market expansion, motor EMC performance will become one of the key indicators of competitiveness in the automotive industry.

[0003] Currently, automotive privacy curtain motors on the market generally suffer from poor EMC performance due to their small size, high current, and low noise. However, due to limited space, conventional improvement methods are not very effective. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide an EMC filter device that can suppress commutator spark signals, which is a common problem in the current automotive privacy curtain motors used in the market due to their small size, large current, and poor noise, resulting in low EMC performance. This device can significantly suppress commutator spark signals and greatly improve EMC performance.

[0005] The technical problem to be solved by this utility model can be achieved through the following technical solution:

[0006] An EMC filtering device for suppressing motor commutator spark signals includes a motor having a commutator, characterized in that the EMC filtering device is a ring-shaped varistor mounted on the commutator.

[0007] In a preferred embodiment of this utility model, the annular varistor is soldered to the hook of the commutator.

[0008] In a preferred embodiment of this utility model, the motor further includes a brush holder board and a PCB board. The PCB board and the brush holder board are connected by two power terminals and one grounding plate to form a complete filtering circuit.

[0009] In a preferred embodiment of this utility model, the upper end of the grounding plate is soldered to the PCB board, and the lower end of the grounding plate is riveted to the motor housing.

[0010] In a preferred embodiment of this utility model, a filter capacitor and an overcurrent protector are provided on the PCB board.

[0011] By adopting the above technical solution, this utility model significantly improves the EMC emission interference problem by adding a ring-shaped varistor to the commutator, solving a long-standing rectification pain point and achieving the goal of meeting the needs of most customers. The ring-shaped varistor of this utility model effectively suppresses the emission interference problem caused by commutator sparks at the source: since the commutator spark signal is a constantly changing voltage (du / dt), the ring-shaped varistor can absorb this surge voltage and dissipate it into the air as heat, thereby reducing the outward propagation of spark interference. Furthermore, this device is versatile, widely applicable, cost-controllable, and suitable for various products and circuits. Its EMC performance meets the EMC standards for new energy vehicles. Currently, it covers products such as privacy curtain motors, seat leg rest motors, and L-shaped motors. Attached Figure Description

[0012] Figure 1 This is an exploded view of the motor of this utility model.

[0013] Figure 2 for Figure 1 Enlarged schematic diagram at point I.

[0014] Figure 3 This is an enlarged schematic diagram of the brush holder board and PCB board of this utility model.

[0015] Figure 4 This is a schematic diagram showing the assembly between the brush holder board, PCB board and motor housing of this utility model.

[0016] Figure 5 This is a schematic diagram of the PCB board structure of this utility model.

[0017] Figure 6 This is a schematic diagram of the electrical principle of the PCB board of this utility model. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] See Figures 1 to 4 The figure shows an EMC filter device for suppressing commutator spark signals in a motor. The motor 100 includes a commutator 110, a brush holder plate 120, and a PCB board 130. The PCB board 130 and the brush holder plate 120 are connected via two power terminals 140a and 140b and a grounding plate 150, forming a complete filter circuit. The brush holder plate 120 and the PCB board 130 constitute a brush holder assembly. The upper end of the grounding plate 150 is soldered to the PCB board 130, and the lower end is riveted to the motor housing 160 of the motor 100.

[0020] The brush holder assembly is internally equipped with electronic components for matching filtering. The design is mainly based on the risks of EMC emission test items. For example, the inductor is selected to be of the maximum value in a limited space, the capacitor is matched according to its own resonant characteristics and EMC frequency band requirements, the overcurrent protector is selected based on the product current and disconnection time, and the varistor is selected based on its own clamping characteristics and the product transient performance.

[0021] Due to the limited space, the filter circuit could not be laid out, so an additional PCB board 130 was added to move the filter capacitors and overcurrent protectors to PCB board 130, ensuring that there was enough space to accommodate them. In this way, more filter capacitors were laid out on PCB board 130, which can suppress low-frequency and high-frequency interference and meet a wider range of more stringent requirements.

[0022] The EMC filtering device of this invention is a ring varistor 200, which is soldered to the hook 111 of the commutator 110. The ring varistor 200 can suppress spark signals in the 30MHz-1000MHz range, reducing interference propagation from the source and improving the commutation life of the motor.

[0023] The components on PCB board 130 are selected from brands with strong adaptability, mainly for filtering resonance, which further suppresses the interference filtered by the ring varistor 200, and finally absorbs and weakens it. At the same time, the design is simple and can be applied to different products and circuits.

Claims

1. An EMC filtering device for suppressing commutator spark signals in a motor, comprising a motor having a commutator, characterized in that, The EMC filter is a ring-shaped varistor, which is mounted on the commutator.

2. The EMC filtering device for suppressing motor commutator spark signals according to claim 1, characterized in that, The annular varistor is soldered to the hook of the commutator.

3. An EMC filtering device for suppressing motor commutator spark signals according to claim 1 or 2, characterized in that, The motor also includes a brush holder board and a PCB board. The PCB board and the brush holder board are connected by two power terminals and one grounding plate, thus forming a complete filtering circuit.

4. The EMC filtering device for suppressing motor commutator spark signals according to claim 3, characterized in that, The upper end of the grounding plate is soldered to the PCB board, and the lower end of the grounding plate is riveted to the motor housing.

5. An EMC filtering device for suppressing motor commutator spark signals according to claim 3, characterized in that, The PCB board is equipped with filter capacitors and overcurrent protectors.

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