FIELD

[0001] Embodiments of the present disclosure generally relate to a wearable device, and more specifically, to a fan module and a mask.

BACKGROUND

[0002] Fans comprising a motor and air blades are well known in the art. They are typically used to cool a hot object (e.g., a processor or a hard disk) at a high temperature by forcing an air stream over the hot object, in a manner known as “forced cooling”. However, in some applications, the fan runs at low temperatures. For example, in a cold winter environment, people may wear fresh air masks for air quality reasons, or to reduce humidity and reduce the risk of foggy glasses. In such situations, fans may be used for ventilation, rather than for cooling.

[0003] Due to the temperature characteristics of the iron core and bearing oil in the motor, the magnetic activation of the iron core decreases rapidly at low temperatures, while the oil resistance of the bearing oil increases rapidly. This will result in higher power consumption of the motor and decreased motor speed. The decrease of the motor speed will reduce the performance of the fan, reducing the ventilation and thus the comfort of a user wearing the mask. In the application of a fresh air mask with a fan, the fan is usually powered by a battery. The higher power consumption of the motor at low temperatures leads to a shortened battery life of the fan.

[0004] US2018/0054152A1 discloses a method of starting and/or driving a fan at low temperature.

[0005] However, there remains a need for further improvements to reduce the power consumption of a fan operating at low temperatures while bringing back the fan performance.

SUMMARY

[0006] Embodiments of the present disclosure provide a fan module and a mask.

[0007] In a first aspect, a fan module is provided. The fan module comprises a motor comprising a stator and a rotor, the stator comprising an iron core and excitation coils surrounding the iron core, the rotor comprising a bearing; one or more heating coils arranged between the iron core and the excitation coils and/or arranged to surround the bearing; a temperature sensor configured to measure an internal temperature of the fan module; and a controller configured to determine a temperature of the motor based on the measured internal temperature and to control a power supply of the one or more heating coils based on the determined temperature of the motor.

[0008] According to embodiments of the present disclosure, the one or more heating coils may be in thermal contact with the iron core when arranged between the iron core and the excitation coils. With this arrangement, the iron core can be heated according to the determined temperature of the motor thereby increasing the magnetic activation of the iron core, and heat dissipation can be prevented at a low temperature. The one or more heating coils may be in thermal contact with the bearing when surrounding the bearing. With this arrangement, the oil in the bearing can be heated according to the determined temperature of the motor, thereby reducing the oil resistance. In this way, the power consumption of the motor can be reduced and the performance of the motor can be improved.

[0009] In some embodiments, the controller is configured to energize the one or more heating coils to heat the motor when the determined temperature of the motor is below a temperature threshold. In this way, the motor will be heated when its temperature drops below the temperature threshold, thereby ensuring stable and improved performance of the fan module.

[0010] In some embodiments, the controller is configured to cease energizing the one or more heating coils when the determined temperature of the motor exceeds a temperature threshold. In this way, the motor can be heated in a non-constant manner, thereby reducing the total power consumption of the fan module.

[0011] In some embodiments, the controller is configured to control a power and/or a heating time of the one or more heating coils to control a total power consumption of the motor and the one or more heating coils. In this way, the total power consumption of the motor and the one or more heating coils can be further reduced.

[0012] In some embodiments, the temperature sensor is in contact with the motor. In this way, the temperature sensor can directly measure the temperature of the motor, so that the heating of the motor by the one or more heating coils can be controlled in a simple manner. [0013] In some embodiments, the fan module further comprises a printed circuit board, wherein the temperature sensor is arranged on the printed circuit board and configured to measure a temperature of the printed circuit board, and wherein the controller is configured to determine the temperature of the motor based on the measured temperature of the printed circuit board. With this arrangement, the temperature of the motor can be obtained or determined without a dedicated sensor. The temperature of the motor can be determined by an existing sensor on the printed circuit board for sensing the temperature of a control unit or the like. In this way, additional space and product design for installing a dedicated temperature sensor for the motor are no longer needed, which reduces the cost of the product.

[0014] In some embodiments, the stator further comprises a thermal insulation layer arranged between the one or more heating coils and the excitation coils when the iron core is in thermal contact with the one or more heating coils. In this way, heat dissipation can be further prevented, thereby reducing the total power consumption of the fan module.

[0015] In some embodiments, the fan module further comprises a battery for supplying power to the one or more heating coils. This arrangement can decrease the size and weight of the fan module.

[0016] In some embodiments, the motor is a brushless DC electrode. This arrangement can reduce the noise generated by the fan module.

[0017] In some embodiments, the fan module further comprises a switch for starting and stopping the fan module. This arrangement enables easy operation for starting and stopping the fan module, thereby facilitating operation and reducing the power consumption of the fan module.

[0018] In a second aspect, a mask is provided. The mask comprises the fan module as mentioned in the above first aspect. According to embodiments of the present disclosure, the mask is provided with a fan module with reduced power consumption and improved performance. Furthermore, user experience can be improved.

[0019] It is to be understood that the Summary is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the description below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other objectives, features and advantages of the present disclosure will become more apparent through a more detailed depiction of example embodiments of the present disclosure in conjunction with the accompanying drawings, wherein in the example embodiments of the present disclosure, same reference numerals usually represent the same components.

[0021] FIG. 1 schematically illustrates a mask with a fan module according to embodiments of the present disclosure;

[0022] FIG. 2 schematically illustrates an exploded view of a fan module of a mask according to embodiments of the present disclosure;

[0023] FIG. 3 schematically illustrates a block diagram of a fan module according to embodiments of the present disclosure;

[0024] FIGs. 4A-4B schematically illustrate a top view and a side view of a motor according to embodiments of the present disclosure;

[0025] FIG. 5 schematically illustrate a sectional view of an iron core of a stator according to embodiments of the present disclosure;

[0026] FIG. 6 schematically illustrates a sectional view of an iron core of a stator according to alternative embodiments of the present disclosure;

[0027] FIG. 7 schematically illustrates a sectional view of a bearing of a rotator according to embodiments of the present disclosure.

[0028] Throughout the drawings, the same or similar reference symbols are used to indicate the same or similar elements.

DETAILED DESCRIPTION

[0029] The present disclosure will now be discussed with reference to several example embodiments. It is to be understood these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the present disclosure, rather than suggesting any limitations on the scope of the subject matter.

[0030] As used herein, the term “comprises” and its variants are to be read as open terms that mean “comprises, but is not limited to.” The term “based on” is to be read as “based at least in part on.” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment.” The term “another embodiment” is to be read as “at least one other embodiment.” The terms “first,” “second,” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be comprised below. A definition of a term is consistent throughout the description unless the context clearly indicates otherwise.

[0031] With the development of technology, requirements for smart wearable devices such as clothes or masks are increasing. For example, an active mask with a fan has been developed to take away the exhaust gases inside a mask to improve the user’s experience. In some cases, the mask may be worn in cold weather, such as outdoors in winter, so that the temperature of the motor in the fan is low, which leads to a sharp drop in the performance and an increase in power consumption of the fan.

[0032] The above example scenario requires both reducing the power consumption and improving the performance of the fan at low temperatures. Actually, it is important to improve the performance and reduce the power consumption of the fan at low temperatures in some cases, especially for wearable devices, such as masks. Wearable devices are usually battery-powered, and require light weight, long battery life, and high user experience requirements. Wearable devices with fans that meet the above requirements can provide better ventilation to the user with lower power consumption in cold weather and thus an improved user experience.

[0033] Embodiments of the present disclosure provide a mask 100 with a fan module 12. FIG. 1 schematically illustrates a mask 100 with a fan module 12 according to embodiments of the present disclosure. As shown in FIG. 1, the mask 100 comprises a mask body 10 used as an air filter and a fan module 12 installed on the mask body 10. When a user wears the mask 100, the mask 100 forms an air cavity with the user's face. The fan module 12 may be used to suck air into the air chamber from the outside and/or to exhaust air from the air chamber to the outside. In some embodiments, the fan module 12 may comprise a switch 14 for turning the fan module 12 on and off, which enables easy operations for starting and stopping the fan module, thereby facilitating operation and reducing the power consumption of the fan module. It should be noted that the mask 100 shown in FIG. 1 is provided as an example only, and is not intended to be limiting. Alternatively, the mask 100 may have any other structure according to actual needs, and the fan module 12 may be installed on the mask 100 in other manners. [0034] FIG. 2 illustrates an exploded view of a fan module 12 mounted on a mask 100 according to embodiments of the present disclosure. As shown in FIG. 2, the fan module 12 may comprise a housing comprising an upper part 16 and a lower part 24, and a printed circuit board (PCB) 18, a battery 20, and a motor 22 located in the housing. The switch 14 may be located on the upper part 16 of the housing for the user to operate. The fan module 12 can be installed on the mask body 10 through a fan interface/air valve 26. According to embodiments of the present disclosure, the fan module 12 may comprise one or more heating coils for heating the motor 22. The arrangement of the one or more heating coils is not explicitly shown in FIG. 2, but will be described in detail later with reference to FIGs. 5-7. The battery 20 can be used to supply power to the PCB 18, the motor 22, and the one or more heating coils. Such arrangement can decrease the size and weight of the fan module.

[0035] FIG. 3 illustrates a block diagram of a fan module 12 according to embodiments of the present disclosure. The PCB 18 may comprise a control unit 46 and a PCB temperature sensor 48. The motor 22 may be driven by the control unit 46 on the PCB 18 to rotate fan blades (not shown) to promote air circulation.

[0036] FIGs. 4A-4B illustrate a top view and a side view of a motor 22 according to embodiments of the present disclosure. As shown, the motor 22 may comprise a stator 28 and a rotor 30. The stator 28 may comprise an iron core and excitation coils 32 surrounding the iron core. The rotor 30 may comprise a bearing 34 having bearing oil with a viscosity that is temperature dependent. The motor 22 shown in FIGs. 4A-4B is a brushless DC motor. Such arrangement can reduce the noise generated by the fan module. However, it should be noted that the brushless DC motor is provided as an example only and is not intended to be limiting. Alternatively, the motor 22 may be designed as any other type of motor according to actual needs.

[0037] Returning to FIG. 3, the temperature of the motor 22 may be determined, and based on the determined temperature of the motor 22, the power supply to the one or more heating coils may be controlled by the control unit 46 or other control unit(s) different from the control unit 46. Hereinafter, specific implementation manners of controlling one or more heating coils to heat the motor 22 will be described in detail by utilizing the control unit 46 as an example.

[0038] In an implementation, the fan module 12 may comprise a motor temperature sensor 44. The motor temperature sensor 44 may be installed near the motor 22, preferably in direct contact with the motor 22. The motor temperature sensor 44 is configured to directly measure the temperature of the motor 22. The control unit 46 may be configured to control the power supply to the one or more heating coils based on the temperature measured by the motor temperature sensor 44, so that the performance of the fan module 12 is improved and the power consumption is reduced. In this way, the motor temperature sensor 44 can be used to measure the temperature of the motor directly, so that the heating of the motor by the one or more heating coils can be controlled in a simple manner.

[0039] In another implementation, the fan module 12 may not comprise the motor temperature sensor 44, but instead the PCB temperature sensor 48 may be utilized to indirectly determine the temperature of the motor 22. As long as the structure of the fan module 12 has been determined, the temperature dynamic balance inside the fan module 12 will be fixed, that is, there is a dynamic balancing relationship between the temperature of the motor 22, the temperature measured by the PCB temperature sensor 48, and the ambient temperature. The curves of the temperature of the motor 22 and the temperature measured by the PCB temperature sensor 48 over time can be measured or simulated in advance under different ambient temperatures. In the case where the ambient temperature and the temperature measured by the PCB temperature sensor 48 are known, the temperature of the motor 22 can be determined according to the aforementioned dynamic balancing relationship determined in advance. In other words, the temperature measured by the PCB temperature sensor 48 is affected by the ambient temperature and the motor 22. When the ambient temperature is determined, the temperature of the motor 22 can be obtained from the temperature measured by the PCB temperature sensor 48.

[0040] In some embodiments, the ambient temperature may also be determined from the temperature measured by the PCB temperature sensor 48. For example, when the motor in the fan module 12 does not work and remains in the environment for a period of time, the temperature inside the fan module 12 would be consistent with the ambient temperature. Therefore, the temperature measured by the PCB temperature sensor 48 is equal to the ambient temperature. Once the initial ambient temperature is determined, no matter whether the fan module 12 is running or not in the subsequent process, the PCB temperature sensor 48 will be affected and slowly change in response to a change of the ambient temperature. According to the temperature change rate of the temperature sensor and a predetermined relationship between the pre-measured ambient temperature and the temperature sensed by the PCB temperature sensor 48, the change of the ambient temperature can be determined. Therefore, when the ambient temperature is determined, the control unit 46 can determine the temperature of the motor 22 based on the temperature measured by the PCB temperature sensor 48, thereby controlling the power supply to the one or more heating coils. With this arrangement, the temperature of the motor can be obtained or determined without a dedicated sensor. The temperature of the motor can be determined by the existing PCB temperature sensor 48. In this way, additional space and product design for installing a dedicated temperature sensor for the motor are no longer needed, which reduces the cost of the product. It is understood that the PCB temperature sensor 48 can be any type of temperature sensor. For example, in some embodiments, the PCB temperature sensor 48 may be a thermistor.

[0041] In some embodiments, the control unit 46 may be configured to supply power to the one or more heating coils to heat the motor 22 when the determined temperature of the motor 22 is lower than the temperature threshold, and stop supplying power to one or more heating coils when the determined temperature of the motor 22 exceeds the temperature threshold. The temperature threshold may be predetermined, or may be set by the user. The heating power to the one or more heating coils may be constant. Therefore, the power supply to the one or more heating coils can be controlled in a simple manner without the need for complicated control programs or controllers. In this way, the motor can be heated in a non constant manner, thereby reducing the total power consumption of the fan module.

[0042] In alternative embodiments, the control unit 46 may be configured to control the power and/or heating duration of the one or more heating coils based on the determined temperature of the motor 22, thereby controlling the total power consumption of the motor 22 and the one or more heating coils. Additionally, the control unit 46 can be configured to supply power to the one or more heating coils with a higher power when the temperature of the motor 22 is far below the temperature threshold, supply power to the one or more heating coils with a lower power when the temperature of the motor approaches the temperature threshold, and stop supplying power to the one or more heating coils when the temperature of the motor is higher than the temperature threshold. Preferably, the control unit 46 can control the power and/or heating duration of the one or more heating coils to minimize the total power consumption of the motor 22 and the one or more heating coils. In this way, the motor can be heated in a non-constant manner, thereby further reducing the total power consumption of the motor and the one or more heating coil. [0043] The arrangement of the motor 22 with one or more heating coils will be described in detail below with reference to FIGs. 5-7.

[0044] FIG. 5 illustrates a sectional view of an iron core 36 of a stator 28 according to embodiments of the present disclosure. The iron core 36 is wound with excitation coils 32. The one or more heating coils 38 are arranged between the iron core 36 and the excitation coils 32. The one or more heating coils 38 can heat the iron core 36 under the control of the control unit 46, thereby increasing the magnetic activation of the iron core. Additionally, there may be a direct or indirect heat transfer path between the stator and the rotor. Thereby, the bearing oil in the bearing 30 can also be heated, thereby reducing the oil resistance of the bearing oil. The one or more heating coils 38 are located below the excitation coils 32 to prevent heat dissipation. With this arrangement, the iron core can be heated according to the temperature of the motor and heat dissipation can be prevented at a low temperature, thereby reducing the power consumption of the motor and improving the performance of the motor.

[0045] FIG. 6 illustrates a sectional view of an iron core 36 of a stator 38 according to alternative embodiments of the present disclosure. The same reference numerals are used to denote the components described in FIG. 6 having the same structure as the components described in FIG. 5, and the description thereof will be omitted. As shown in FIG. 6, a thermal insulation layer 40 is arranged between the one or more heating coils 38 and the excitation coils 32. With such arrangement, heat dissipation can be further prevented, thereby reducing the total power consumption of the fan module 12.

[0046] FIG. 7 illustrates a sectional view of a bearing 34 of a rotator 30 according to embodiments of the present disclosure. In some embodiments, the bearing 34 may be surrounded by one or more heating coils 42. One or more heating coils 42 can heat the bearing 34 under the control of the control unit 46, thereby reducing the oil resistance of the bearing oil of the bearing 34. In this way, the oil in the bearing can be further heated, thereby reducing the oil resistance, thus improving the performance of the motor. In some embodiments, only the iron core 36 is in thermal contact with one or more heating coils. In other embodiments, only the bearing 34 is in thermal contact with one or more heating coils. In yet further embodiments, both the iron core 36 and the bearing 34 are in thermal contact with one or more heating coils. Alternatively, the iron core 36 and the bearing 34 are in thermal contact with the same heating coil, so that the heating of the motor 22 can be controlled in a simpler manner. It should be noted that the arrangements of one or more heating coils 38 and one or more heating coils 42 in the drawings are only for illustration, and are not intended to be limiting. The winding manner of the one or more heating coils can be arranged according to the actual structure of the motor so as to heat the motor.

[0047] The fan module may start the motor intermittently according to the temperature of the motor after the motor is started, directly heat the iron core by means of the one or more heating coils, and preventing heat dissipation by means of the excitation coil. Accordingly, the fan module may achieve improved performance with low total power consumption.

[0048] It should be appreciated that the above detailed embodiments of the present disclosure are only to exemplify or explain principles of the present disclosure and not to limit the present disclosure. Therefore, any modifications, equivalent alternatives and improvements, etc. without departing from the spirit and scope of the present disclosure shall be comprised in the scope of protection of the present disclosure. Meanwhile, appended claims of the present disclosure aim to cover all the variations and modifications falling under the scope and boundary of the claims or equivalents of the scope and boundary.