Patent Description:
The performance of a wireless charging system comprising e.g. a wireless charging device as a wireless charging transmitter and e.g. a mobile device as a wireless charging receiver can be vastly improved by the integration of a cooling system targeting the charging mobile device receiver. To reduce charging durations the wireless charging market is driven towards higher charging powers, increasing the thermal losses that are in turn affecting the battery charging process. Most of the mobile devices nowadays protect the battery by leveling the charging power as to stabilize the receiver temperature below 40degC. No measure taken to cool the mobile device while charging results in the mobile device lowering the charging power after a few minutes ultimately leading to extended charging durations.

<CIT> and <CIT> respectively disclose a cooling facility arranged within a wireless charger. The wireless charger comprises an outlet nozzle which is arranged along the blowing duct and has at least one outlet opening leading out of the wireless charging transmitter. In order to cool the wireless charger, air is blown through the blowing duct.

It is an object of the invention to propose a wireless charging transmitter which is simple in design and is able to cool a mobile device and the wireless charging transmitter effectively. It is a further object of the invention to provide a wireless charging transmitter with compact dimensions. Additionally it is an object of the invention to provide a wireless charging system that, for a given charging power, ensure the shortest charging duration. The present invention provides a wireless charging transmitter according to claim <NUM> and a wireless charging system according to claim <NUM>.

According to the invention a wireless charging transmitter comprises a charging surface mat comprising a plurality of air flow openings, at least one support arranged on or alongside the charging surface mat in order to keep a charging mobile device at a distance to the charging surface mat, a wireless charging antenna construction comprising one or more transmission coils, an electric fan, a PCBA with electronics for controlling a charging process and a cooling process, a suction duct which is created between the charging surface mat and the wireless charging antenna construction, a blowing duct which is created between the wireless charging antenna construction and the PCBA, a connection chamber which connects the suction duct and the blowing duct, wherein the electric fan is arranged within the connecting chamber and divides the connection chamber, wherein while the electric fan is running: air flows from a surrounding of the wireless charging transmitter through the openings of the charging surface mat into the suction duct, to the connection chamber, through the fan and through the blowing duct and out of the wireless charging transmitter. Such a wireless charging transmitter is able to cool a mobile device which is set on top of the wireless charging antenna construction using air surrounding the charging device by creating an airflow sucking air through the openings of the charging surface mat into the suction duct. By this an airflow cools the mobile device and is subsequently used to cool the charging transmitter. Such a cooling is simple since the mobile device as well as the wireless charging transmitter is cooled by using a single electrical fan. The system circulates air from a vehicle interior around the mobile device and along a backside of the mobile device to the openings of the charging surface mat and streams it through the suction duct and the blowing duct of the wireless charging transmitter. Such a wireless charging transmitter can meet the needs of an efficient mobile device cooling system which allows a high charging power.

According to the invention the wireless charging transmitter comprises an outlet nozzle which is arranged along the blowing duct and has at least one outlet opening leading out of the wireless charging transmitter, wherein the outlet opening is arranged in one of the supports and in a side wall of the wireless charging transmitter or in a bottom wall of the wireless charging transmitter. Since the air is guided away through the wireless charging transmitter a mixing of fresh air and air heated by the mobile device is avoided in order to keep cooling effective.

Additionally the invention provides that the suction duct runs parallel to the blowing duct. Such a design allows compact dimension of the wireless charging transmitter since existing installation space is used for laying the ducts.

The invention provides that a rotation axis of a fan blade of the electric fan runs vertical to a longitudinal axis of the suction duct and runs vertical to a longitudinal axis of the blowing duct and runs vertical to the charging surface mat. Such a design allows compact dimension of the wireless charging transmitter since only low installation height is necessary for the electric fan.

The invention provides that the electric fan is either axial or centrifugal type. Both types of fans are available as costeffective standard component. Centrifugal type fans (blowers) are offering the best performance considering the available volume.

Finally the invention provides that the wireless charging antenna construction is arranged between the charging surface mat and the PCBA. Due to this special arrangement, the wireless charging antenna construction is cooled twice, namely once by the suction duct on the top and once by the blowing duct on the bottom.

The invention provides a wireless charging system which comprises a wireless charging transmitter according to at least one of claims <NUM> to <NUM> and a mobile device, wherein the mobile device rests on the wireless charging transmitter at a distance away of the charging surface mat. Such a system allows an effective cooling of the mobile device and components of the wireless charging transmitter by a surrounding air. Such a wireless charging system is able to cool a mobile device and a wireless charging transmitter with the surrounding air by creating an airflow by suction through the openings of the charging surface mat through the suction duct. By this an airflow which cools the mobile device receiver is subsequently used to cool the wireless charging transmitter. Such a cooling is effective since the mobile device as well as the wireless charging transmitter is cooled by using a single electrical fan. Fresh air streams from a vehicle interior around the mobile device and along a backside of the mobile device to the openings of the charging surface mat and streams through the suction duct and the blowing duct of the wireless charging transmitter. Such a wireless charging system can meet the needs of an efficient cooling system for mobile device and wireless charging transmitter. The Combined effect allows efficient cooling a subsequent longer capability of the mobile device to charge at maximum allowed power.

According to the invention a PCBA is a Printed Circuit Board Assembly comprising a PCB namely a Printed Circuit Board and several electronic and/or electrical components.

The foregoing and other features and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawing, in which:.

<FIG> shows a schematic section view of a first embodiment of an inventive wireless charging transmitter <NUM>. The wireless charging transmitter <NUM> comprises a charging surface mat <NUM> comprising a plurality of air flow openings 3a - 3d. The wireless charging transmitter <NUM> comprises two supports 4a, 4b arranged alongside the charging surface mat <NUM> in order to keep a charging mobile device MD at a distance d away of the charging surface mat <NUM>. The wireless charging transmitter <NUM> comprises a wireless charging antenna construction <NUM> comprising three transmission coils 6a, 6b, 6c. The wireless charging transmitter <NUM> comprises an electric fan <NUM>. The wireless charging transmitter <NUM> comprises a PCBA <NUM> with electronics <NUM> for controlling a charging process and a cooling process. The wireless charging transmitter <NUM> comprises one or several suction ducts <NUM> which is/are created between the charging surface mat <NUM> and the wireless charging antenna construction <NUM>. The wireless charging transmitter <NUM> comprises one or more blowing ducts <NUM> which is/are created between the wireless charging antenna construction <NUM> and the PCBA <NUM>. The wireless charging transmitter <NUM> comprises a connection chamber <NUM> which connects the suction duct <NUM> and the blowing duct <NUM>. The electric fan <NUM> is arranged in the connection chamber <NUM> and separates the connection chamber <NUM> between an intake suction room <NUM> and a oulet blower room <NUM>. The intake suction room <NUM> is connected to the suction duct(s) <NUM> and the bloerw room <NUM> is connected to the blowing duct(s) <NUM>. When the electric fan <NUM> is displacing air A, flows from a surrounding SR of the wireless charging transmitter <NUM> through the openings 3a - 3d of the charging surface mat <NUM> into the suction duct(s) <NUM>. This air A streams from the suction duct(s) <NUM> to the connection chamber <NUM> and is then blown out by the electric fan <NUM>. Following the air A is expelled from the blower room <NUM> through the blowing duct(s) <NUM> and streams then through the blowing duct <NUM> to exit the wireless charging transmitter <NUM>.

The wireless charging transmitter <NUM> comprises one or several outlet nozzles <NUM> which is/are arranged and end of the blowing duct(s) <NUM> and has/have one or more outlet openings 15a allowing air to escape the wireless charging transmitter <NUM>, wherein the outlet opening(s) 15a is/are arranged in a side wall <NUM> of the wireless charging transmitter <NUM>.

<FIG> shows a second outlet nozzle <NUM> which has an outlet opening 17a leading out of the wireless charging transmitter <NUM>, wherein the outlet opening 17a is arranged in a bottom wall <NUM> of the wireless charging transmitter <NUM>. This second outlet nozzle is arranged alternatively or cumulatively to the first outlet nozzle <NUM>.

<FIG> shows a third outlet nozzle <NUM> which has several outlet opening 19a, 19b, 19c exhausting air out of the wireless charging transmitter <NUM> on the top side through the mat, wherein the outlet openings 19a, 19b, 19c are arranged in the support 4a of the wireless charging transmitter <NUM>. This third outlet nozzle <NUM> is arranged alternatively or cumulatively to the first outlet nozzle <NUM> or to the second outlet nozzle <NUM> or to the first outlet nozzle <NUM> and the second outlet nozzle <NUM>.

The suction duct(s) <NUM> run(s) parallel to the blowing duct(s) <NUM>. A rotation axis R7a of a fan blade 7a the electric fan <NUM> runs vertical to a longitudinal axis L10 of the suction duct(s) <NUM>, runs vertical to a longitudinal axis L11 of the blowing duct(s) <NUM> and runs vertical to a plane E defined by a surface 2a of the charging surface mat <NUM>.

The air A which is sucked into the openings 3a - 3d of the charging surface mat <NUM> streams from the surrounding SR along a backside BS of the mobile device MD and cools the mobile device MD which is heated by the transfer of energy losses from the wireless charging antenna construction <NUM> and a receiving coil RC which is mounted in the mobile device MD.

The air A which runs through the suction duct(s) <NUM> and the blowing duct(s) <NUM> cools the wireless charging antenna construction <NUM> and the PCBA <NUM>.

The flow of the air within the wireless charging transmitter <NUM> is indicated by dotted lines.

The wireless charging antenna construction <NUM> is arranged between the charging surface mat <NUM> and the PCBA <NUM>. This means that an upper side 5a and a lower side 5b of the wireless charging antenna construction <NUM> is cooled by the air A flowing in the suction duct(s) <NUM> and the blowing duct(s) <NUM> propelled by the electric fan <NUM>.

Claim 1:
Wireless charging transmitter (<NUM>) comprising
- a charging surface mat (<NUM>) comprising a plurality of air flow openings (3a, 3b, 3c),
- at least one support arranged (4a, 4b) on or alongside the charging surface mat (<NUM>) in order to keep a charging mobile device (MD) at a distance (d) away of the charging surface mat (<NUM>),
- a wireless charging antenna construction (<NUM>) comprising one or more transmission coils (6a, 6b, 6c),
- an electric fan (<NUM>),
- a PCBA (<NUM>) with electronics (<NUM>) for controlling a charging process and a cooling process,
- a suction duct (<NUM>) which is created between the charging surface mat (<NUM>) and the wireless charging antenna construction (<NUM>),
- a blowing duct (<NUM>) which is created between the wireless charging antenna construction (<NUM>) and the PCBA (<NUM>),
- a connection chamber (<NUM>) that connects the suction duct (<NUM>) and the blowing duct (<NUM>),
- wherein the electric fan (<NUM>) is arranged within the connection chamber (<NUM>) and divides the connection chamber (<NUM>),
- wherein while the electric fan (<NUM>) is running: air (A) flows from a surrounding (SR) of the wireless charging transmitter (<NUM>) through the openings (3a, 3b, 3c) of the charging surface mat (<NUM>) into the suction duct (<NUM>), to the connection chamber (<NUM>), through the fan (<NUM>) and through the blowing duct (<NUM>) and out of the wireless charging transmitter (<NUM>),
- wherein the wireless charging transmitter (<NUM>) comprises an outlet nozzle (<NUM>; <NUM>; <NUM>) which is arranged along the blowing duct (<NUM>) and has at least one outlet opening (15a; 17a; 19a, 19b, 19c) leading out of the wireless charging transmitter (<NUM>), wherein the outlet opening (15a; 17a; 19a, 19b, 19c) is arranged in one of the supports (4a, 4b) and at least in a side wall (<NUM>) of the wireless charging transmitter (<NUM>) or in a bottom wall (<NUM>) of the wireless charging transmitter (<NUM>).