Patent Description:
In recent years, due to the energy-saving trend of the air-conditioning units, high-efficiency brushless DC motors have been used to replace induction motors to drive blowers. These brushless DC motors are generally driven by inverters, which adopt a pulse width modulation (hereinafter referred to as PWM) method as a driving method. When using the PWM driving method, a common mode voltage is always generated because that the neutral point potential of the winding is not zero. In the case of high frequency, a voltage between the inner ring and outer ring of the bearing (bearing capacitor branch) is generated by the common mode voltage via a loop, which is formed by the coupling capacitors generated between various structural parts of the motor, including the stator, the rotor, the rotor core, the bearing bracket, and the bearing capacitors. This voltage between the inner ring and the outer ring of the bearing caused by the common mode voltage is called shaft voltage. The shaft voltage contains the high-frequency components of the high-speed switching action of the semiconductor during PWM driving. If the shaft voltage reaches the insulation breakdown voltage of the lubricating oil film inside the bearing, the current will be generated due to discharge, resulting in local erosion between the inner surface and the balls of the bearing, that is, electric corrosion (also called electric erosion) occurring inside the bearing. When the electric corrosion is aggravated, wave-shaped abrasion will occur inside the bearing, such as the inner ring, outer ring or balls of the bearing, causing abnormal noise and decrease in the service lift of the bearing. <CIT> relates to a motor and electrical equipment equipped with the same and discloses a brushless motor having a discrete capacitor connected between a stator core and bearing bracket of the motor. <CIT> relates to an electric motor and electric device equipped with the same and discloses a brushless motor having conductive patterns wherein the conductive patterns are connected to a ground line and an outer ring conducting part of a bearing. <CIT> relates to a structure for reducing shaft voltage of an electric motor and discloses connecting an end cap of a motor to a stator via a conducting wire and connectors.

An object of embodiments of the present application is to provide a brushless motor to solve the problem in the related arts that excessively high shaft voltage of the brushless motor causes electric erosion of the bearing.

In order to achieve the object, the following technical solutions are adopted by the present application: a brushless motor, comprising: a casing having an insulating property; a stator fixed within the casing; and a rotor rotatably arranged within the stator. The stator comprises a stator core and a winding wound around the stator core. The rotor comprises a rotor core and a shaft passing through the rotor core. Two bearings are sleeved on the shaft at positions corresponding to two ends of the rotor core, respectively, and two bearing brackets are installed at two ends of the casing for fixing the two bearing. A first conductive sheet and a second conductive sheet are arranged between at least one of the two bearing brackets and the stator core, and are configured to cooperate to balance a potential of an inner ring and a potential of an outer ring of each of the two bearings. The first conductive sheet and the second conductive sheet are aligned side by side and spaced apart from each other. The first conductive sheet is in electrical connection with the stator core, and the second conductive sheet is in electrical connection with an adjacent bearing bracket. A supporting board is configured to support the first conductive sheet and the second conductive sheet and the supporting board is fixed at the casing, and wherein the supporting board is provided with a first conductive pad and a second conductive pad (<NUM>), the first conductive pad is electrically connected to the first conductive sheet, and the second conductive pad is electrically connected to the second conductive sheet, a first electrical contact and a second electrical contact are installed at the casing, the first electrical contact is configured to connect with the first conductive pad, and the second electrical contact is configured to connect with the second conductive pad, the first electrical contact is in electrical connection with the stator core, and the second electrical contact is in electrical connection with the adjacent bearing bracket.

Another object of the present application is to provide an electrical equipment, including the brushless motor as described in the above.

The above one or more technical solutions in embodiments of the present application have at least one of the following technical effects:.

The first conductive sheet in electrical connection with the stator core, and the second conductive sheet in electrical connection with the bearing bracket are arranged within the brushless motor. The first conductive sheet and the second conductive sheet are aligned side by side and spaced apart from each other, such that the first conductive sheet and the second conductive sheet can cooperate to adjust a capacitive reactance between the stator core and the bearing bracket, so as to balance a potential of an inner ring and a potential of an outer ring of each of the two bearings. In this way, a potential difference between the inner ring and the outer ring of each of the two bearings is decreased, and in turn the shaft voltage is decreased, thereby avoiding the electric erosion of the bearing.

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments or the exemplary art will be briefly described herein below. The accompanying drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. All of the embodiments in paragraphs <NUM> to <NUM> of the detailed description relate to the present invention.

In the drawings, the following reference numerals are adopted:
<NUM>: Brushless motor; <NUM>: Casing; <NUM>: Conductive piece; <NUM>: Stator; <NUM>: Stator core; <NUM>: Winding; <NUM>: Insulating skeleton; <NUM>: Sealing board; <NUM>: Plastic package end face; <NUM>: Insertion pin; <NUM>: rotor; <NUM>: Shaft; <NUM>: Rotor core; <NUM>: Bearing; <NUM>: Bearing bracket; <NUM>: First bracket; <NUM>: Second bracket; <NUM>: Supporting board; <NUM>: Printed circuit board; <NUM>: Drive circuit; <NUM>: First conductive pad; <NUM>: Second conductive pad; <NUM>: First conductive sheet; <NUM>: First electrical regions; <NUM>: First connecting regions; <NUM>: First lead wire; <NUM>: First insulating protective layer; <NUM>: First insulating layer; <NUM>: Second conductive sheet; <NUM>: Second electrical regions; <NUM>: Second connecting regions; <NUM>: Second lead wire; <NUM>: Second insulating protective layer; <NUM>: Second insulating layer; <NUM>: Dielectric layer; <NUM>: First electrical contact; <NUM>: First insertion part; <NUM>: First conductor part; <NUM>: First electrically conductive part; <NUM>: First protrusion; <NUM>: Second electrical contact; <NUM>: Second insertion part; <NUM>: Second conductor part; <NUM>: Second electrically conductive part; <NUM>: Second protrusion; <NUM>: Adhesive layer; <NUM>: Metal connecting needle; and <NUM>: Elastic conductive pin.

In order to make the purposes, technical solutions, and advantages of the present application clearer and more understandable, the present application will be further described in detail hereinafter with reference to the accompanying drawings and embodiments. It should be understood that the embodiments described herein are only intended to illustrate but not to limit the present application.

It should be noted that when an element is described as "fixed" or "arranged" on/at another element, it means that the element can be directly or indirectly fixed or arranged on/at another element. When an element is described as "connected" to/with another element, it means that the element can be directly or indirectly connected to/with another element. Moreover, terms like "first" and "second" are only used for the purpose of description, and will in no way be interpreted as indication or hint of relative importance or implicitly indicate the number of the referred technical features. Thus, the features prefixed by "first" and "second" will explicitly or implicitly represent that one or more of the referred technical features are included. In the description of the present application, "multiple"/ "a plurality of" refers to the number of two or more than two, unless otherwise clearly and specifically defined. The meaning of "several" is one or more than one, unless otherwise specifically defined. It should be understood that terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating orientation or positional relationship are based on the orientation or the positional relationship shown in the drawings, and are merely for facilitating and simplifying the description of the present application, rather than indicating or implying that a device or component must have a particular orientation, or be configured or operated in a particular orientation, and thus should not be construed as limiting the application. In the present application, unless otherwise specifically stipulated and defined, terms like "install", "connect", "couple", "fix" should be construed broadly, for example, they may indicate a fixed connection, a detachable connection, or an integral as a whole; may be a mechanical connection, or an electrical connection; may be in direct connection, or indirect connection via an intermediate, and may also reflect internal communication of two elements or interactions between two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to specific conditions.

A brushless motor <NUM> provided by the present application is described hereinbelow with reference to <FIG> and <FIG>. The brushless motor <NUM> comprises: a casing <NUM>, a stator <NUM>, a rotor <NUM>, two bearings <NUM>, and two bearing brackets <NUM>. Both the stator <NUM> and the rotor <NUM> are installed in the casing <NUM>, and the stator <NUM> is configured to drive the rotor <NUM> to rotate. The two bearings <NUM> are installed at the rotor <NUM> to support the rotor <NUM>. The two bearing brackets <NUM> support the two bearings <NUM>, respectively, thereby supporting the rotor <NUM>. In the meanwhile, the two bearing brackets <NUM> are installed at two ends of the casing <NUM>, respectively, so as to support the rotor <NUM> within the casing <NUM> and enabling the rotor <NUM> to flexibly rotate. The use of the bearing brackets <NUM> to support the bearings <NUM> can achieve more stable supporting of the bearings <NUM>, thereby ensuring excellent rotation of the bearings <NUM>.

The casing <NUM> has insulating property, and plays the main role of support and protection. The casing <NUM> can be injection-molded using a resin material, which can facilitate processing and manufacture, and can have good insulation effect. In addition, the casing <NUM> can also dissipate heat. It can be understood that in order to improve the heat dissipation efficiency, some heat dissipation fins can be arranged on the casing <NUM>.

The stator <NUM> comprises a stator core <NUM> and a winding <NUM>. The winding <NUM> is wound on the stator core <NUM>. When a current passes through the winding <NUM>, a magnetic field is generated, and the magnetic field is reinforced and guided by the stator core <NUM>. The stator core <NUM> is formed by stacking a plurality of the silicon steel sheets to reduce eddy currents. The stator core <NUM> generally comprises a plurality of tooth-like structures, and the winding <NUM> is wound on the respective teeth. These tooth-like structures are enclosed to for a circular shape, which enables the rotor to be arranged within the stator <NUM> and to be driven to rotate.

As shown in <FIG>, in order to realize a firm connection between the winding <NUM> and the stator core <NUM> as well as facilitate the installation of the winding <NUM> on the teeth of the stator core, an insulating skeleton <NUM> can be provided to support the winding, and the insulating skeleton <NUM> is fixed on the stator core <NUM>. It can be understood that, to facilitate the connection between the driver circuit and the winding <NUM>, a lead end of the winding <NUM> can be fixed on the insulating skeleton <NUM>, so that it is convenient to realize the connection with the drive circuit.

Furthermore, in an embodiment, a sealing board <NUM> may be arranged on the insulating skeleton <NUM>, and the sealing board <NUM> is preferably made of an insulating material to fix the lead terminals of the winding <NUM> on the sealing board <NUM>, thereby facilitating It is electrically connected to the drive circuit <NUM>, or a wire is conveniently drawn out to be electrically connected to the external drive circuit. In other words, the drive circuit <NUM> can be set in the casing <NUM>, or an external drive circuit can be set, which is connected to the external drive circuit through a wire.

Preferably, the drive circuit <NUM> can be arranged inside the casing <NUM> to reduce the volume, improve the integration, and facilitate the use. It can be understood that, the printed circuit board <NUM> can be set in the casing <NUM>, and the drive circuit <NUM> can be made in the printed circuit board <NUM>. The lead terminal of the winding <NUM> can be made into the insertion pin <NUM> to facilitate electrical connection with the printed circuit board <NUM>.

The rotor <NUM> comprises: a shaft <NUM> and a rotor core <NUM>. The shaft <NUM> passes through a center of the rotor core <NUM>, such that the rotor core <NUM> can be supported by the shaft <NUM>; and the rotor core <NUM> is placed in the stator <NUM>. Therefore, when the winding <NUM> is energized, an alternating magnetic field is generated on the stator core <NUM> to drive the rotor core <NUM> to rotate and in turn drive the shaft <NUM> to rotate. In addition, the rotor core <NUM> may be a combined structure of the rotor core <NUM> and magnets, or may be formed by punching the silicon steel sheets into a cage-like shape by a punching machine, and stacking punched silicon steel sheets, casting with aluminum for processing.

Both the two bearings <NUM> are sleeved outside the shaft <NUM>, and are located at the two ends of the rotor core <NUM>, respectively. Since the weight of the rotor <NUM> is mostly concentrated at the position of the rotor core <NUM>, the center of gravity of the rotor <NUM> is also at the position corresponding to the rotor core <NUM>. Such arrangement of the two bearings <NUM> at the two ends of the rotor core <NUM> respectively can better support the shaft <NUM>, and in turn support the rotor core <NUM>, which makes the rotor core <NUM> and the shaft <NUM> more stably rotate. The arrangement of the two bearings <NUM> for supporting the shaft <NUM> enables the rotation of the shaft <NUM> more flexibly.

Two bearings <NUM> are arranged within the two bearing brackets <NUM>, respectively, such that the two bearings <NUM> and in turn the rotor <NUM> are supported by corresponding bearing brackets <NUM>. The two bearing brackets <NUM> are respectively installed at two ends of the casing <NUM> to support the rotor <NUM> in the casing <NUM> and enable the rotor <NUM> to rotate flexibly in the casing <NUM>. Moreover, the stator core <NUM> is insulated from the respective bearing brackets <NUM>. The use of the two bearing brackets <NUM> can support the bearings <NUM> more stably, ensure the smooth rotation between the outer ring and the inner ring of each bearing <NUM>, and can reduce vibration, avoid the bearings <NUM> from creeping. The outer rings of the bearings <NUM> are in electrical connection to the bearing brackets <NUM>, respectively.

As shown in <FIG> and <FIG>, in an embodiment, the stator <NUM> and the casing <NUM> are plastic encapsulated into an integrated structure, so that the stator <NUM> is firmly and stably fixed in the casing <NUM>. The casing <NUM> can be manufactured to have a relatively small size, thereby reducing the volume and the weight of the manufactured brushless motor <NUM>. For example, when the casing <NUM> is made by injection molding, the stator <NUM> can be placed in a mold, so that when the casing <NUM> is injection molded, the casing <NUM> and the stator <NUM> form an integrated structure. It can be understood that, in some other embodiments, the casing <NUM> can also be made separately, and the stator <NUM> can be fixed in the casing <NUM>.

In an embodiment, a plastic package end face <NUM> may be formed on an end face of the stator core <NUM> to protect the stator core <NUM>, so that external impurities are prevented from entering the stator core <NUM> and external conductive piece is prevented from connecting with the stator core <NUM>. Specifically, the plastic package end face <NUM> can be arranged on the insulating skeleton <NUM>, so that the plastic package end face <NUM> is directly formed on the end face of the stator core <NUM> after the insulating skeleton <NUM> is mounted on the stator core <NUM>.

In the above embodiment, when the stator <NUM> and the casing <NUM> are plastic encapsulated into an integrated structure, the plastic package end face <NUM> can be formed on the end face of the stator <NUM> at the same time, which is convenient for the processing and manufacture, as well as the molding of the plastic package end face <NUM>. It can be understood that, if a sealing board <NUM> is arranged on the stator <NUM>, the sealing board <NUM>, the stator <NUM>, and the casing <NUM> can be plastic encapsulated into an integrated structure.

As shown in <FIG>, in an embodiment, the two bearing brackets <NUM> are composed of a first bracket <NUM> and the second bracket <NUM>. The first bracket <NUM> and the second bracket <NUM> are located at the two ends of the casing <NUM>, respectively. The first bracket <NUM> is used as an end cover of the casing <NUM>, and the second bracket <NUM> and the casing <NUM> are plastic encapsulated into an integral structure, that is, when the casing <NUM> is injection molded, the second bracket <NUM> can be placed in the mold, such that the second bracket <NUM> and the casing <NUM> can be injection molded as a whole during the injection molding of the casing <NUM>. In this way, the second bracket <NUM> is firmly fixed in the casing <NUM>, which facilitates the processing and manufacture and reduces the weight and the cost.

As shown in <FIG>, in an embodiment, both the two ends of the casing <NUM> may be designed to be open structures, and both the two bearing brackets <NUM> may be used as two end covers. Such that a fan and other structures can be installed in one end of the casing <NUM> to better dissipate heat. It can be understood that such a structure has more practical significance for motors that require output at both ends of the shaft <NUM>. In addition, the configuration of two ends of the casing <NUM> as the open structures and the two bearing brackets <NUM> as end covers may increase the strength of the whole brushless motor <NUM> via the bearing bracket <NUM>. In addition, the bearing bracket <NUM> can also be used for heat dissipation, in order to improve heat dissipation efficiency. The use of the bearing bracket as the end cover of the casing <NUM> enables the whole end cover to be made of a metal, or only a part of the end cover that supports the bearing <NUM> to be made of the metal, thereby preventing the bearing <NUM> from creeping and ensuring stable rotation of the bearing <NUM>.

Furthermore, in the above embodiment, the two bearing brackets <NUM> are in electrical connection, so that the potentials of the two bearing brackets <NUM> are kept consistent, and the potentials of the outer rings of the two the bearing <NUM> are kept consistent. In the above embodiment, the first bracket <NUM> and the second bracket <NUM> are electrically connected, so that the first bracket <NUM> and the second bracket <NUM> have the same potential. Specifically, the conductive piece <NUM> may be arranged within the casing <NUM> to electrically connect the two bearing brackets <NUM>. It can be understood that the conductive piece <NUM> can also be attached from the outside of the casing <NUM> to electrically connect the two bearing brackets <NUM>.

Furthermore, in the above embodiment, a first conductive sheet <NUM> and a second conductive sheet <NUM> are arranged between the first bracket <NUM> and the stator core <NUM>. The first conductive sheet <NUM> and the second conductive sheet <NUM> are aligned side by side and spaced apart from each other. The first conductive sheet <NUM> is in electrical connection with the stator core <NUM>, and the second conductive sheet <NUM> is in electrical connection with the first bracket <NUM>. In this way, the conductivity on the first bracket <NUM> and the second bracket <NUM> can be introduced to the second conductive sheet <NUM>, and the conductivity on the stator core <NUM> can be introduced to the first conductive sheet <NUM>, such that a capacitor is formed between the first conductive sheet <NUM> and the second conductive sheet <NUM>, and capacitance between the stator core <NUM> and each bearing bracket <NUM> can be adjusted. An equivalent capacitance between the stator core <NUM> and the inner ring of each bearing <NUM> is approximate to or equal to an equivalent capacitance between the stator core <NUM> and the outer ring of each bearing <NUM>, that is, the equivalent capacitance between the stator core <NUM> and the inner ring of each bearing <NUM> and the equivalent capacitance between the stator core <NUM> and the outer ring of each bearing <NUM> are balanced, in turn, the potential between the outer ring of each bearing <NUM> and the inner ring of each bearing <NUM> are balanced, such that the potential of the outer ring of each bearing <NUM> and the potential of the inner ring of each bearing <NUM> are similar, a potential difference between the outer ring of each bearing <NUM> and the inner ring of each bearing <NUM> are reduced, thereby decreasing a shaft voltage and avoid the bearing <NUM> from electric erosion. It can be understood that in the above embodiment, the first conductive sheet <NUM> and the second conductive sheet <NUM> can also are arranged between the second bracket <NUM> and the stator core <NUM>.

In the above embodiment, as the casing <NUM>, the second bracket <NUM>, and the stator core <NUM> are plastic-encapsulated into an integrated structure, during arrangement of the first conductive sheet <NUM> and the second conductive sheet between the second bracket <NUM> and the stator core <NUM>, the first conductive sheet <NUM> and the second conductive sheet <NUM> are required to be placed in the mold in advance when manufacturing the casing <NUM>, such that the first conductive sheet <NUM>, the second conductive sheet <NUM>, and the casing <NUM> are plastic-encapsulated into an integrated structure.

As shown in <FIG>, in an embodiment, when both the two ends of the casing <NUM> may be designed to be open structures, the first conductive sheet <NUM> and the second conductive sheet <NUM> can be arranged between each of the two ends of the stator core <NUM> and each of the two bearing brackets <NUM>. In such case, the two bearing brackets <NUM> may not be electrically connected, both the two first conductive sheets <NUM> at two ends of the stator core <NUM> are in electrical connection with the stator core <NUM>, while the two second conductive sheets <NUM> are electrically connected to the corresponding adjacent bearing brackets <NUM>, respectively, thus, the first conductive sheets <NUM> and the second conductive sheets <NUM> at the two ends of the stator core <NUM> are adopted to adjust the capacitive reactance between the stator core and the two bearing brackets <NUM>, respectively, thereby potential difference between the inner and outer rings of the two the bearing <NUM> are adjusted separately. It can be understood that, in some embodiments, the two bearing brackets <NUM> may also be electrically connected, in such condition, the arrangement of the first conductive sheet <NUM> and the second conductive sheet <NUM> between each of the two ends of the stator core <NUM> and each of the two bearing brackets <NUM> has greater adjustment space and adjustment margin.

As shown in <FIG>, in an embodiment, when both the two ends of the casing <NUM> are designed to be open structures, the two bearing brackets <NUM> can also be electrically connected, so that the potentials of the two bearing brackets <NUM> are equivalent, the first conductive sheet <NUM> and the second conductive sheet <NUM> can be arranged between one of the bearing brackets <NUM> and the stator core <NUM>, and the capacitive reactance between each bearing bracket <NUM> and the second conductive sheet <NUM> can be adjusted by the first conductive sheet <NUM> and the second conductive sheet <NUM>, which is convenient for the manufacture, reduces the production cost, and is easy to use.

It can be understood that, in some other embodiments, in case that the structures of the two bearing brackets <NUM> are different, the potential differences between the inner rings and the outer rings of the two bearings <NUM> are also different, the two bearing brackets <NUM> cannot be electrically connected, thus, the capacitive reactance between only one of the bearing brackets <NUM> and the stator core <NUM> is adjusted; or the capacitive reactance between the respective bearing brackets <NUM> and the stator core <NUM> are adjusted separately.

In the following embodiments, unless otherwise indicated by two bearing brackets <NUM> or open structures of the two ends of the casing, then the bearing bracket <NUM> refers to the first bracket <NUM>.

As shown in <FIG>, in an embodiment, the brushless motor <NUM> further comprises a supporting board <NUM>. The supporting board <NUM> is fixed at the casing <NUM>, and the first conductive sheet <NUM> and the second conductive sheet <NUM> are mounted at the supporting board <NUM>, so that the first conductive sheet <NUM> and the second conductive sheet <NUM> are supported by the supporting board <NUM>, which enables the first conductive sheet <NUM> and the second conductive sheet <NUM> to be installed within the casing <NUM>.

As shown in <FIG>, in an embodiment, the supporting board <NUM> can be a printed circuit board <NUM>, and the first conductive sheet <NUM> and the second conductive sheet <NUM> are mounted on two sides of the printed circuit board <NUM>, so that the first conductive sheet <NUM> and the second conductive sheet <NUM> are supported by the printed circuit board <NUM>, which facilitates the installation and fixation of the first conductive sheet <NUM> and the second conductive sheet <NUM>, and reduces the occupied space. The brushless motor <NUM> is made to be smaller, thus improving the integration.

Referring to <FIG> and <FIG>, in the above embodiment, the drive circuit <NUM> can be arranged on the printed circuit board <NUM> to facilitate driving the winding <NUM>. The first conductive sheet <NUM> and the second conductive sheet <NUM> are both insulated and disconnected from the drive circuit <NUM>, so as to prevent the first conductive sheet <NUM> and the second conductive sheet <NUM> from affecting the drive circuit <NUM>.

Furthermore, in the above embodiment, the printed circuit board <NUM> can be made relatively large, the drive circuit <NUM> can be arranged on a region of the printed circuit board <NUM>, and the first conductive sheet <NUM> and the second conductive sheet <NUM> can be arranged on another region of the printed circuit board <NUM>, so as to reduce the influence of the first conductive sheet <NUM> and the second conductive sheet <NUM> on the drive circuit <NUM>.

Please refer to <FIG>. In an embodiment, the supporting board <NUM> may not be the printed circuit board <NUM>, that is, the supporting board <NUM> may be separately provided to support the first conductive sheet <NUM> and the second conductive sheet <NUM>, which can reduce The influence of the first conductive sheet <NUM> and the second conductive sheet <NUM> on the drive circuit <NUM> on the printed circuit board <NUM> is small.

In an embodiment, since the printed circuit board <NUM> is generally made relatively small, the supporting board <NUM> and the printed circuit board <NUM> can be arranged on the same plane to reduce the occupied space thereof within the casing <NUM>. It can be understood that, in some other embodiments, the supporting board <NUM> and the printed circuit board <NUM> may be aligned side by side and spaced apart from each other.

Referring to <FIG>, in an embodiment, when the first conductive sheet <NUM> and the second conductive sheet <NUM> are arranged on each of the two ends of the stator core <NUM>,.

the printed circuit board <NUM> and the supporting board <NUM> may be respectively arranged at the two ends of the stator core <NUM>, that is, the first conductive sheet <NUM> and the second conductive sheet <NUM> at one end of the stator core <NUM> are installed on the printed circuit board <NUM>, while the first conductive sheet <NUM> and the second conductive sheet <NUM> at the other end of the stator core <NUM> are installed on the printed circuit board <NUM>. In some other embodiments, the supporting board <NUM> may be provided at each end of the stator core <NUM>, and the two the first conductive sheet <NUM> and the second conductive sheet <NUM> may be installed on the corresponding supporting board <NUM>.

Referring to <FIG>, in an embodiment, a first insulating protective layer <NUM> is arranged on one side of the first conductive sheet <NUM> away from the second conductive sheet <NUM>, so that the first insulating protective layer <NUM> can protect the first conductive sheet <NUM> by reducing the impact of other components in the brushless motor <NUM> on the first conductive sheet <NUM>. Similarly, a second insulating protective layer <NUM> is arranged on one side of the second conductive sheet <NUM> away from the first conductive sheet <NUM>. The second insulating protective layer <NUM> can protect the second conductive sheet <NUM> by reducing the impact of other components in the brushless motor <NUM> on the second conductive sheet <NUM>. Especially when the first conductive sheet <NUM> and the second conductive sheet <NUM> are installed on the two sides of the supporting board <NUM>, the supporting board <NUM> can prevent impurities from entering the gap between the first conductive sheet <NUM> and the second conductive sheet <NUM>. The insulating protective layer <NUM> can cooperate with the supporting board <NUM> to protect the first conductive sheet <NUM>, and the second insulating protective layer <NUM> can cooperate with the supporting board <NUM> to protect the second conductive sheet <NUM>.

Referring to <FIG>, in an embodiment, a first insulating layer <NUM> is arranged one side of the first conductive sheet <NUM> close to the second conductive sheet <NUM>, so that when the first conductive sheet <NUM> and the second conductive sheet <NUM> are aligned side by side and spaced apart from each other, a better non-electrical connection between the first conductive sheet <NUM> and the second conductive sheet <NUM> is ensured. Similarly, the second insulating layer <NUM> is arranged on one side of the second conductive sheet <NUM> close to the first conductive sheet <NUM>, to ensure a better non-electrical connection between the first conductive sheet <NUM> and the second conductive sheet <NUM>. Especially when the first conductive sheet <NUM> and the second conductive sheet <NUM> are installed on the two sides of the printed circuit board <NUM>, the first conductive sheet <NUM> and the second conductive sheet <NUM> can be better disconnected from the drive circuit <NUM> of the printed circuit board <NUM>.

Furthermore, in the above-mentioned embodiment, the first insulating layer <NUM> and the first insulating protective layer <NUM> may be arranged on the two sides of the first conductive sheet <NUM>, respectively, to better protect the first conductive sheet <NUM>, and when the first conductive sheet <NUM> is installed, the first conductive sheet <NUM> can be better prevented from affecting or being affected by other parts in the brushless motor <NUM>. Similarly, the second insulating layer <NUM> and the second insulating protective layer <NUM> may be arranged on the two sides of the second conductive sheet <NUM>, respectively, to better protect the second conductive sheet <NUM>, and when the second conductive sheet <NUM> is installed, the second conductive sheet <NUM> can be better prevented from affecting or being affected by other parts in the brushless motor <NUM>.

Referring to <FIG>, in an embodiment, a dielectric layer <NUM> is arranged between the first conductive sheet <NUM> and the second conductive sheet <NUM>, and the first conductive sheet <NUM> and the second conductive sheet <NUM> are respectively arranged on two sides of the dielectric layer <NUM>, such that the first conductive sheet <NUM> and the second conductive sheet <NUM> can be supported by the dielectric layer <NUM>, and the first conductive sheet <NUM>, the dielectric layer <NUM>, and the second conductive sheet <NUM> are made into a whole, which is convenient for installation. The dielectric layer <NUM> may be an insulating layer to ensure that the first conductive sheet <NUM> and the second conductive sheet <NUM> are in non-electrical connection. For example, in this embodiment, the first conductive sheet <NUM> is installed on the supporting board <NUM> via an adhesive layer, so that the second conductive sheet <NUM> is also supported on the supporting board <NUM>, and the first conductive sheet <NUM> and the second conductive sheet <NUM> are arranged at the same side of the supporting board <NUM>. It can be understood that, in some other embodiments, the second conductive sheet <NUM> can also be installed on the supporting board <NUM> via the adhesive layer, so that the first conductive sheet <NUM> is also supported on the supporting board <NUM>, and the first conductive sheet <NUM> and the second conductive sheet <NUM> are arranged at the same side of the supporting board <NUM>. The adhesive layer can be a conductive layer or an insulating layer. When the supporting board <NUM> is the printed circuit board <NUM>, the adhesive layer preferably adopts an insulating layer.

Referring to <FIG>, in an embodiment, the dielectric layer <NUM> is arranged between the first conductive sheet <NUM> and the second conductive sheet <NUM>, and the first conductive sheet <NUM> and the second conductive sheet <NUM> are supported by the dielectric layer <NUM>, then the second conductive sheet <NUM> can be installed on the adjacent bearing bracket <NUM> via the adhesive layer <NUM>, so that the first conductive sheet <NUM> is also supported on the adjacent bearing bracket <NUM>, so as to reduce the occupied space in the casing <NUM>. Since the second conductive sheet <NUM> needs to be electrically connected to the adjacent bearing bracket <NUM>, the adhesive layer <NUM> can use a conductive layer. It can be understood that, the adhesive layer <NUM> can also use an insulating layer, in such case, the second conductive sheet <NUM> needs to be led out and electrically connected to the bearing bracket <NUM>. It can be understood that, in some other embodiments, the first conductive sheet <NUM> can be installed on the adjacent bearing bracket <NUM> via the adhesive layer <NUM>, so that the second conductive sheet <NUM> is also supported on the bearing bracket <NUM> to reduce the occupied space in the casing <NUM>. In such case, the adhesive layer <NUM> needs to use an insulating layer, to avoid electrical connection between the corresponding bearing bracket <NUM> and the first conductive sheet <NUM>.

Referring to <FIG>, in the above embodiment, when the second conductive sheet <NUM> is electrically connected to the bearing bracket <NUM>, the first conductive sheet <NUM> can extend to form a connecting pad, and the adhesive layer <NUM> is arranged between the connecting pad and the bearing bracket <NUM>. A metal connecting needle <NUM> is arranged within the casing <NUM>, and the metal connecting needle <NUM> is connected to the stator core <NUM>, such that when the bearing bracket <NUM> is installed, the metal connecting needle <NUM> is brought into abutment with the connecting pad, so as to electrical connection between the first conductive sheet <NUM> and the stator core <NUM>, which is convenient in connection. It can be understood that, in some embodiments, the first conductive sheet <NUM> and the stator core <NUM> may be electrically connected via a wire.

Referring to <FIG>, in an embodiment, a dielectric layer <NUM> is arranged between the first conductive sheet <NUM> and the second conductive sheet <NUM>, and the first conductive sheet <NUM> and the second conductive sheet <NUM> are supported by the dielectric layer <NUM>, then the second conductive sheet <NUM> can be installed on an adjacent plastic package end face <NUM> via the adhesive layer <NUM>, so that the first conductive sheet <NUM> is also supported on the adjacent plastic package end face <NUM>, so as to reduce the occupied space in the casing <NUM>. The adhesive layer <NUM> may use a conductive layer or an insulating layer. It can be understood that, in some other embodiments, the first conductive sheet <NUM> can be installed on the adjacent plastic package end face <NUM> via the adhesive layer <NUM>, so that the second conductive sheet <NUM> is also supported on the plastic package end face <NUM>, so as to reduce the occupied space in the casing <NUM>.

Referring to <FIG>, in the above embodiment, a first electrical contact <NUM> can be installed at the insulating skeleton <NUM>, with one end of the first electrical contact <NUM> extending to the plastic package end face <NUM>, and the other end of the first electrical contact <NUM> being in connection with the stator core <NUM>. Moreover, a second electrical contact <NUM> can also be installed at the insulating skeleton <NUM>, with one end of the second electrical contact <NUM> being led to the plastic package end face <NUM>, and the other end of the second electrical contact <NUM> extending out of the plastic package end face <NUM> to be in abut with the bearing bracket <NUM>. When the first conductive sheet <NUM> is installed on the plastic package end face <NUM>, the first conductive sheet <NUM> can be connected to one end of the first electrical contact <NUM>, so as to electrically connect the first conductive sheet <NUM> and the stator core <NUM>. The second conductive sheet <NUM> leads to a connecting wire to be electrically connected to one end of the second electrical contact <NUM>. During the installation of the bearing bracket <NUM>, the other end of the second electrical contact <NUM> abuts the bearing bracket <NUM>, so as to electrically connect the second conductive sheet <NUM> with the bearing bracket <NUM>.

Referring to <FIG> and <FIG>, in an embodiment, the second conductive sheet <NUM> is arranged on one side of the supporting board <NUM> away from the stator core <NUM>, and the first conductive sheet <NUM> is arranged on one side of the supporting board <NUM> near the stator core <NUM>, which facilitates the electrical connection between the first conductive sheet <NUM> and the stator core <NUM>, as well as the electrical connection between the second conductive sheet <NUM> and the corresponding bearing bracket <NUM>. It can be understood that, in other embodiments, the first conductive sheet <NUM> can be arranged on one side of the supporting board <NUM> away from the stator core <NUM>, and the second conductive sheet <NUM> can be arranged on one side of the supporting board <NUM> close to the stator core <NUM>, in such case, wiring pads can be arranged on the two sides of the supporting board <NUM>, such that the first conductive sheet <NUM> can be electrically connected with the wiring plates arranged on the supporting board <NUM> on the side close to the stator core <NUM>, and the second conductive sheet <NUM> can be electrically connected to the stator core <NUM>. The supporting board <NUM> is electrically connected to the wiring pad on the side away from the stator core <NUM>.

As shown in <FIG> and <FIG>, according to the invention, when the first conductive sheet <NUM> and the second conductive sheet <NUM> are installed on the supporting board <NUM>, the supporting board <NUM> is provided with a first conductive pad <NUM> and a second conductive pad <NUM>, the first conductive pad <NUM> is electrically connected to the first conductive sheet <NUM>, and the second conductive pad <NUM> is electrically connected to the second conductive sheet <NUM>. A first electrical contact <NUM> and a second electrical contact <NUM> are installed at the casing <NUM>, the first electrical contact <NUM> is electrically connected to the stator core <NUM>, and the second electrical contact <NUM> is electrically connected to the adjacent bearing bracket <NUM>. The first electrical contact <NUM> is used to connect the first conductive pad <NUM>, and the second electrical contact <NUM> is used to connect the second conductive pad <NUM>, thereby facilitating the electrical connection between the first conductive sheet <NUM> and the stator core <NUM>, as well as the electrical connection between the second conductive sheet <NUM> and the bearing bracket <NUM>. The supporting board <NUM> may be a printed circuit board <NUM> or a board provided separately.

Specifically, referring to <FIG>, in the above embodiment, the first electrical contact <NUM> comprises: a first conductor part <NUM>, a first electrically conductive part <NUM>, and the first insertion part <NUM>. The first conductor part <NUM> and the first electrically conductive part <NUM> are formed on the first insertion part <NUM>, the first conductor part <NUM> and the first electrically conductive part <NUM> are supported by the first insertion part <NUM>, and the first insertion part <NUM> is fixed at the casing <NUM>, so as to support the first conductor part <NUM> and the first electrically conductive part <NUM> at the casing <NUM>. The first conductor part <NUM> is used to connect with the first conductive pad <NUM>, and the first electrically conductive part <NUM> is in abut connection with the stator core <NUM>, as shown in <FIG>, so that when the supporting board <NUM> is installed, the first conductor part <NUM> is connected to the first conductive pad <NUM>, and then to the first conductive sheet <NUM>, thus realizing the electrical connection between the first conductive sheet <NUM> and the stator core <NUM>.

Furthermore, in the above embodiment, the first conductor part <NUM> protrudes from one end of a lateral side of the first insertion part <NUM>. The first electrically conductive part <NUM> comprises: a first section <NUM>, where the first section <NUM> is formed by extending the other end of the lateral side of the first insertion part <NUM> towards a direction of one face of the first insertion part <NUM>; and a second section <NUM>, where the second section <NUM> is formed by extending a free end of the first section <NUM> towards a direction away from the first conductor part <NUM>. That is, the first electrically conductive part <NUM> comprises: a first section <NUM> and a second section <NUM>. The first section <NUM> is formed by extending a lateral side of the first insertion part <NUM> towards the direction of one face of the first insertion part <NUM>. The second section <NUM> is formed by extending the free end of the first section <NUM> towards the direction away from the first conductor part <NUM>. The first conductor part <NUM> and the first electrically conductive part <NUM> are formed by extending the same side of the first insertion part <NUM>. In this way, it is convenient for processing and installation, as well as the electrical connection with the stator core <NUM>.

Furthermore, in the above embodiment, the first electrical contact <NUM> is formed by punching a metal sheet. It can be understood that, the first electrical contact <NUM> can also be formed by bending a metal sheet. In some other embodiments, the first electrical contact <NUM> may be formed by welding multiple metal sheets.

Furthermore, in the above embodiment, the first electrical contact <NUM> can be installed on the sealing board <NUM> to better support the first electrical contact <NUM>. Furthermore, the first insertion part <NUM> can be fixed on the insulating skeleton <NUM>, and the first conductor part <NUM> can be fixed on the sealing board <NUM>, so as to better fix the first electrical contact <NUM>. Furthermore, a first protrusion <NUM> protrudes from the first insertion part <NUM>, so that the first insertion part <NUM> is more firmly fixed on the insulating skeleton <NUM>.

Furthermore, referring to <FIG>, in the above embodiment, the first conductive sheet <NUM> can be connected to the first conductive pad <NUM> via a first lead wire <NUM>. Referring to <FIG>, in the above embodiment, the second conductive sheet <NUM> can be connected to the second conductive pad <NUM> via a second lead wire <NUM>.

Specifically, referring to <FIG> and <FIG>, in the above embodiment, the second electrical contact <NUM> includes: a second conductor part <NUM>, a second electrically conductive part <NUM>, and a second insertion part <NUM>. The second conductor part <NUM> and the second electrically conductive part <NUM> are installed on the second insertion part <NUM>. The second conductor part <NUM> and the second electrically conductive part <NUM> are supported by the second insertion part <NUM>; and the second insertion part <NUM> is fixed at the casing <NUM>, such that the second conductor part <NUM> and the second electrically conductive part <NUM> are supported at the casing <NUM>. The second conductor part <NUM> is used to connect with the second conductive pad <NUM>, and the second electrically conductive part <NUM> is used to abut with the bearing bracket <NUM>. Referring to <FIG> and <FIG>, when the supporting board <NUM> is installed, the second conductor part <NUM> is connected to the second conductive pad <NUM>, and in turn connected to the second conductive sheet <NUM>. When the bearing bracket <NUM> is installed, the second electrically conductive part <NUM> abuts with the bearing bracket <NUM>, so as to electrically connect the second conductive sheet <NUM> with the bearing bracket <NUM>.

Furthermore, in the above embodiment, the second conductor part <NUM> protrudes from one end of a lateral side of the second insertion part <NUM>. The second electrically conductive part <NUM> includes: a first portion <NUM>, extended from the other end of the lateral side of the second insertion part <NUM>; a second portion <NUM> formed by extending a free end of the first portion <NUM> towards a face of the second insertion part <NUM>; and a third portion <NUM> formed by extending a free end of the second portion <NUM> in a direction away from the second insertion part <NUM>. That is, the second electrically conductive part <NUM> includes: the first portion <NUM>, the second portion <NUM>, and the third portion <NUM>. The first portion <NUM> is extended from the lateral side of the second insertion part <NUM>. The second portion <NUM> is extended from the free end of the first portion <NUM> towards a face of the second insertion part <NUM>. The third portion <NUM> is extended from the free end of the second portion <NUM> in the direction away from the second insertion part <NUM>. The third portion <NUM> is in parallel to the second conductor part <NUM>, and both the second conductor part <NUM> and the second electrically conductive part <NUM> are arranged at the same lateral side of the second insertion part <NUM>, which is convenient for process and installation, as well as the electrical connection with the bearing bracket <NUM>.

Furthermore, in the above embodiment, the second electrical contact <NUM> is formed by punching a metal sheet. It can be understood that, the second electrical contact <NUM> can also be formed by bending a metal sheet. In some other embodiments, the second electrical contact <NUM> may be formed by welding multiple metal sheets.

Furthermore, in the above embodiment, the second electrical contact <NUM> can be installed on the sealing board <NUM> to better support the second electrical contact <NUM>. Furthermore, the second insertion part <NUM> can be fixed on the insulating skeleton <NUM>, and the second conductor part <NUM> and the second electrically conductive part <NUM> can be fixed on the sealing board <NUM>, so as to better fix the second electrical contact. Furthermore, a second protrusion <NUM> protrudes from the second insertion part <NUM>, so that the second insertion part <NUM> is more firmly fixed on the insulating skeleton <NUM>.

Furthermore, in the above embodiment, the sealing board <NUM> is provided, and the first electrical contact <NUM> and the second electrical contact <NUM> are supported by the sealing board <NUM>. When the stator <NUM> and the casing <NUM> are injection molded into an integral structure, the sealing board <NUM> and the casing <NUM> can also be injection molded as a whole, which is convenient for supporting and fixing the first electrical contact <NUM> and the second electrical contact <NUM>, and is convenient for processing and manufacturing.

Furthermore, referring to <FIG>, in an embodiment, an elastic conductive pin <NUM> can also be arranged on the supporting board <NUM>. The second conductive sheet <NUM> is electrically connected to the elastic conductive pin <NUM>, and the elastic conductive pin <NUM> presses against the bearing bracket <NUM> to electrically connect the second conductive sheet <NUM> with the bearing bracket <NUM>.

Referring to <FIG>, in an embodiment, the first conductive sheet <NUM> includes a plurality of first electrical regions <NUM>, and every two adjacent first electrical regions <NUM> are connected by first connecting regions <NUM> which are tearable. The tearable first connecting regions <NUM> are used to connect every two adjacent first electrical regions <NUM> to form the first conductive sheet <NUM>. Thus, in use, the area of the first conductive sheet <NUM> can be adjusted according to the needs, thereby facilitating the adjustment of the capacitive reactance between bearing bracket <NUM> and the stator core <NUM>. Similarly, referring to <FIG>. In an embodiment, the second conductive sheet <NUM> includes a plurality of second electrical regions <NUM>, and every two adjacent second electrical regions <NUM> are connected by the second connecting regions <NUM>, which are tearable. The tearable second connecting regions <NUM> are used to connect every two adjacent second electrical regions <NUM> to form the second conductive sheet <NUM>. Thus, in use, the area of the second conductive sheet <NUM> can be adjusted according to the needs, thereby facilitating the adjustment of the capacitive reactance between bearing bracket <NUM> and the stator core <NUM>.

In an embodiment, the first conductive sheet <NUM> may be a conductive foil. One side of the conductive foil is an adhesive surface having a conductivity property, and the other side of the conductive foil is an insulating surface having an insulating property, which are convenient for use. In use, the first conductive sheet <NUM> can be directly attached to the supporting board <NUM>, or attached to the plastic package end face <NUM>. Meanwhile, it is also convenient to cut the first conductive sheet <NUM> to adjust the area of the first conductive sheet <NUM>. In the same way, the second conductive sheet <NUM> can be a conductive sheet. One side of the conductive foil is an adhesive surface having a conductivity property, and the other side of the conductive foil is an insulating surface having an insulating property, which are convenient for use. In use, the second conductive sheet <NUM> can be directly attached to the supporting board <NUM>, or attached to the plastic package end face <NUM>. Meanwhile, it is also convenient to cut the second conductive sheet <NUM> to adjust the area of the second conductive sheet <NUM>.

In an embodiment, the first conductive sheet <NUM> may be a copper layer fabricated in the printed circuit board <NUM>. Similarly, the second conductive sheet <NUM> may also be a copper layer fabricated in the printed circuit board <NUM>.

The brushless motor <NUM> according to embodiments of the present application can effectively balance the electric potential between the inner ring and the outer ring of each bearing <NUM>, reduce the voltage between the inner ring and the outer ring of each bearing <NUM>, and avoid electric erosion between the inner ring and the outer ring of each bearing <NUM>, thereby ensuring excellent and smooth operation of the brushless motor <NUM>, reducing the noise and the vibration, and prolonging the service life. The brushless motor <NUM> according to embodiments of the present application can be applied to electrical appliances such as air conditioners, washing machines, microwave ovens, refrigerators, and the like.

Furthermore, an embodiment of the present application further provides an electrical equipment, which includes the brushless motor <NUM> as described in any of the above embodiments. The use of the brushless motor <NUM> in the electrical equipment can ensure a good service life of the brushless motor <NUM>.

Claim 1:
A brushless motor (<NUM>), comprising:
a casing (<NUM>) having an insulating property;
a stator (<NUM>) fixed within the casing (<NUM>), the stator (<NUM>) comprising a stator core (<NUM>) and a winding (<NUM>) wound around the stator core (<NUM>); and
a rotor (<NUM>) rotatably arranged within the stator (<NUM>), the rotor (<NUM>) comprising a rotor core (<NUM>) and a shaft (<NUM>) passing through the rotor core (<NUM>), wherein two bearings (<NUM>) are sleeved on the shaft (<NUM>) at positions corresponding to two ends of the rotor core (<NUM>), respectively, and two bearing brackets (<NUM>) are installed at two ends of the casing (<NUM>) for fixing the two bearings (<NUM>);
wherein
a first conductive sheet (<NUM>) and a second conductive sheet (<NUM>) are arranged between at least one of the two bearing brackets (<NUM>) and the stator core (<NUM>), and are configured to cooperate to balance a potential of an inner ring and a potential of an outer ring of each of the two bearings (<NUM>);
the first conductive sheet (<NUM>) and the second conductive sheet (<NUM>) are aligned side by side and spaced apart from each other; and
the first conductive sheet (<NUM>) is in electrical connection with the stator core (<NUM>), and the second conductive sheet (<NUM>) is in electrical connection with an adjacent bearing bracket (<NUM>);
characterized in that:
a supporting board (<NUM>) is configured to support the first conductive sheet (<NUM>) and the second conductive sheet (<NUM>);
the supporting board (<NUM>) is fixed at the casing (<NUM>);
wherein
the supporting board (<NUM>) is provided with a first conductive pad (<NUM>) and a second conductive pad (<NUM>), the first conductive pad (<NUM>) is electrically connected to the first conductive sheet (<NUM>), and the second conductive pad (<NUM>) is electrically connected to the second conductive sheet (<NUM>);
a first electrical contact (<NUM>) and a second electrical contact (<NUM>) are installed at the casing (<NUM>), the first electrical contact (<NUM>) is configured to connect with the first conductive pad (<NUM>), and the second electrical contact (<NUM>) is configured to connect with the second conductive pad (<NUM>); and
the first electrical contact (<NUM>) is in electrical connection with the stator core (<NUM>); and
the second electrical contact (<NUM>) is in electrical connection with the adjacent bearing bracket (<NUM>).