Blower

Abstract

The invention relates to a blower (10) comprising: a housing (12) on which an intake opening (1232) and an outlet opening (1212) are formed and which forms a conveying chamber (14), a motor chamber (18) and an electronics chamber (22), the housing (12) being designed such that a fluid can be conveyed from the intake opening (1232) through the motor chamber (18) and the conveying chamber (14) to the outlet opening (1212); an impeller (16) which is arranged in the conveying chamber (14), the conveying chamber (14) and the impeller (16) being designed such that a fluid is conveyed through the conveying chamber (14) when the impeller (16) rotates; an electric motor (20) which is arranged in the motor chamber (18) and which is designed to drive the impeller (16) in rotation; and a motor electronics unit (24) which is arranged in the electronics chamber (22) and which is designed to control the electric motor (20) in order to drive the impeller (16), the housing (12) having a pressure equalization opening (1235) via which the electronics chamber (22) is fluidically connected to the motor chamber (18), a pressure equalization element (32) being arranged at the pressure equalization opening (1235) and being designed to allow gas to be exchanged between the electronics chamber (22) and the motor chamber (18) via the pressure equalization opening (1235) and to prevent liquid from infiltrating into the electronics chamber (22) via the pressure equalization opening (1235).

Description

[0001] The present invention relates to a blower, in particular a blower for an internal combustion engine, comprising: a housing in which an intake opening and an outlet opening are formed and which forms a conveying chamber, a motor chamber and an electronics chamber, wherein the housing is designed such that a fluid can be conveyed from the intake opening through the motor chamber and the conveying chamber to the outlet opening, an impeller arranged in the conveying chamber, wherein the conveying chamber and the impeller are designed such that a fluid is conveyed through the conveying chamber when the impeller rotates, an electric motor arranged in the motor chamber and designed to drive the impeller rotationally, and motor electronics arranged in the electronics chamber and designed to control the electric motor to drive the impeller.

[0002] Unless otherwise defined, in the following, an axial direction is parallel to an axis of rotation of the impeller, a radial direction is perpendicular to the axis of rotation of the impeller, and a transverse plane is transverse to the axis of rotation of the impeller.

[0003] A blower of this type is known from US Patent 2016 / 0238031 A1. During operation, a pumped fluid flows around the electric motor located in the motor chamber, thus achieving efficient cooling of the electric motor. This allows the blower to remain switched on for a relatively long period. However, contaminants and / or liquids carried into the electronics chamber by the aspirated fluid flow can damage the motor electronics, impairing the blower's functionality and potentially leading to total blower failure. Document EP2562425 A2 also provides background information on the present invention.

[0004] Against this background, the task arises to create a reliable blower that allows for relatively long operating times.

[0005] This problem is solved by a blower having the features of main claim 1.

[0006] The blower according to the invention comprises a housing with an intake opening and an outlet opening, forming a conveying chamber, a motor chamber, and an electronics chamber. The housing is designed such that a fluid can be conveyed from the intake opening through the motor chamber and the conveying chamber to the outlet opening. Specifically, during operation of the blower, a fluid is conveyed into the housing via the intake opening, then through the motor chamber and the conveying chamber, and finally out of the housing via the outlet opening. The motor chamber can be arranged either upstream or downstream of the conveying chamber. Typically, the housing comprises several housing parts, which are preferably axially connected to one another to facilitate relatively simple assembly of the blower.Typically, the housing has an intake manifold that forms the intake opening and an exhaust manifold that forms the exhaust opening.

[0007] The blower according to the invention comprises an impeller arranged in the pumping chamber. The impeller can be, for example, a side-channel pump impeller or a radial pump impeller. In any case, however, the pumping chamber and the impeller are designed such that a fluid is conveyed through the pumping chamber when the impeller rotates. Typically, the pumping chamber and the impeller are specifically designed such that, when the impeller rotates, a fluid is drawn into the pumping chamber, conveyed through the pumping chamber, and expelled from the pumping chamber. The fluid can either be drawn from the motor chamber into the pumping chamber or expelled from the pumping chamber into the motor chamber. To facilitate easy installation of the impeller in the pumping chamber, the pumping chamber is preferably formed by two axially joined housing parts.

[0008] The blower according to the invention comprises an electric motor arranged in the motor chamber and configured to drive the impeller rotationally. The electric motor comprises a motor stator and a motor rotor, which interact in a known manner to drive the motor rotor rotationally. Preferably, the motor stator comprises at least one electromagnetic stator winding, and the motor rotor is permanently magnetized. Typically, the electric motor is designed as an internal rotor, with the motor stator radially surrounding the motor rotor, and the electric motor is electronically commutated. However, it is also conceivable that the electric motor is designed as an external rotor, with the motor rotor radially surrounding the motor stator, and / or is commutated via a mechanical commutator. In general, the impeller is designed to rotate with the motor rotor. Typically, the impeller is connected to the motor rotor via a rotor shaft.However, it is also conceivable that the impeller is formed as a single piece with the motor rotor.

[0009] The blower according to the invention comprises motor electronics arranged in the electronics chamber and configured to control the electric motor in a known manner to drive the impeller. Generally, the motor electronics comprise a plurality of electronic components and at least one circuit board on which the electronic components are arranged. Preferably, the motor electronics comprise several power semiconductor switches for electronically commutation of a drive current supplied to the electric motor.

[0010] According to the invention, the housing has a pressure equalization opening through which the electronics chamber is fluidically connected to the motor chamber. A pressure equalization element is arranged at the pressure equalization opening, configured to allow gas exchange between the electronics chamber and the motor chamber via the pressure equalization opening and to prevent the ingress of liquid from the motor chamber into the electronics chamber via the pressure equalization opening. Typically, the pressure equalization element comprises a membrane that is permeable to gases but impermeable to liquids and solids. The membrane is arranged such that fluid exchange between the electronics chamber and the motor chamber via the pressure equalization opening can only occur through the membrane.

[0011] Because gas exchange between the electronics chamber and the motor chamber is possible via the pressure equalization opening according to the invention, the formation of potentially harmful overpressure in the electronics chamber can be reliably prevented, even during relatively long operating times of the blower, despite the resulting heating of the motor electronics. The pressure equalization element according to the invention reliably prevents the ingress of potentially harmful liquids and / or contaminants into the electronics chamber. Since the pressure equalization element is arranged inside the housing according to the invention, this generally relatively sensitive element is reliably protected from environmental influences such as splashing water or stone chips. This creates a blower that operates reliably even during relatively long operating times.

[0012] Preferably, the motor chamber is arranged fluid-wise between the intake opening and the pumping chamber, so that the pumped fluid has a particularly low temperature when flowing through the motor chamber. This enables efficient cooling of the electric motor located in the motor chamber.

[0013] Preferably, the motor chamber's flow inlet and outlet are arranged at different axial heights, allowing the conveyed fluid to flow axially through the motor chamber. Particularly preferred are the motor chamber's flow inlet and outlet located on opposite axial sides of the electric motor, ensuring that the conveyed fluid completely surrounds the motor. This enables efficient cooling of the electric motor.

[0014] Preferably, a housing part forming a housing wall separating the electronics chamber from the motor chamber is made of a material with relatively high thermal conductivity, particularly preferably a metal. This enables efficient cooling of the motor electronics arranged in the electronics chamber.

[0015] Preferably, the electronics chamber surrounds the motor chamber at least partially radially. This creates a particularly large common housing wall surface between the electronics chamber and the motor chamber, allowing a particularly large amount of heat to be dissipated from the electronics chamber to the motor chamber via the housing wall separating them. This enables efficient cooling of the motor electronics located in the electronics chamber.

[0016] Preferably, at least one cooling dome projecting towards the motor electronics is formed on a side of a housing wall separating the electronics chamber from the motor chamber, facing the electronics chamber. This cooling dome is in thermal contact with an electronic component and / or a circuit board of the motor electronics. The thermal contact can be achieved either through direct physical contact or via a heat transfer medium, such as a thermal pad or thermal paste, arranged between the cooling dome and the electronic component or circuit board. The heat transfer medium is in direct physical contact with both the cooling dome and the electronic component or circuit board. Typically, the at least one cooling dome is formed on a housing wall section extending substantially in a transverse plane and projects axially from the housing wall.Preferably, several cooling domes of this type are present, which are in thermal contact with different electronic components and / or circuit board sections of the motor electronics. A particularly large amount of waste heat is typically generated by power semiconductor components of the motor electronics; therefore, preferably at least one cooling dome is in thermal contact with a power semiconductor component of the motor electronics or with an area of ​​the circuit board on which a power semiconductor component is located. The at least one cooling dome creates a material connection, and thus a particularly good thermal conductor, between individual components of the motor electronics and the housing wall separating the electronics chamber from the motor chamber, which is surrounded by the pumped fluid on the motor chamber side. This enables particularly efficient cooling, especially of components of the motor electronics that heat up considerably during operation.

[0017] Preferably, the housing forms an intake channel encompassing the intake opening, such that the intake channel and the electronics chamber share a common housing wall section. This common housing wall section is surrounded on the intake channel side by fluid at a particularly low temperature, thereby enabling efficient cooling of the motor electronics located in the electronics chamber.

[0018] To achieve particularly high flow rates, the conveying chamber and the impeller are preferably designed to form a side-channel conveying unit. The conveying chamber comprises at least one side channel. Preferably, the conveying chamber comprises two axially opposed side channels, between which the impeller is arranged. Preferably, the two side channels are formed by two different housing parts.

[0019] Because the motor chamber is permeated by the conveyed fluid according to the invention, and thus the electric motor arranged therein is efficiently cooled, the blower can be equipped with a particularly powerful electric motor, wherein a motor stator of the electric motor comprises at least one stator winding, preferably at least six stator windings.

[0020] An embodiment of the present invention is described below with reference to the accompanying figures. These show: Figure 1 a side view of a blower according to the invention in cutaway view, and Figure 2 A top view of a blower's conveying chamber in a cutaway view.

[0021] The figures show a blower 10 according to the invention with a housing 12, which consists of a first housing part 121, a second housing part 122, a third housing part 123, and a fourth housing part 124, which are arranged axially one above the other and are each made of a metal. The first housing part 121 and the second housing part 122 form a conveying chamber 14 in which an impeller 16 is arranged. The second housing part 122 and the third housing part 123 form a substantially cylindrical motor chamber 18 in which an electric motor 20 is arranged. The third housing part 123 and the fourth housing part 124 form an electronics chamber 22 in which motor electronics 24 are arranged and which comprises a substantially annular chamber region 221 that radially surrounds a first axial end region of the motor chamber 18.

[0022] The third housing part 123 has an intake manifold 1231, which forms an intake channel 1239 with an intake opening 1232. The intake channel 1239 opens into the first axial end region of the motor chamber 18, which faces the electronics chamber 22. The third housing part 123 is designed such that the intake channel 1239 and the electronics chamber 22 share a common housing wall section 1233.

[0023] The first housing part 121 has an outlet nozzle 1211, which forms an outlet channel 1213 with an outlet opening 1212. The outlet channel 1213 is connected to the conveying chamber 14.

[0024] In the second housing part 122, a passage 1221 is formed, which fluidically connects the pumping chamber 14 with the motor chamber 18, so that a fluid can be conveyed from the intake opening 1232 through the intake channel 1239, the motor chamber 18, the pumping chamber 14, and the outlet channel 1213 to the outlet opening 1212. A flow-related inlet 181 of the motor chamber 18, formed by the intake channel 1239, and a flow-related outlet 182 of the motor chamber 18, formed by the passage 1221, are therefore arranged at opposite axial end regions of the motor chamber 18, so that the pumped fluid flows through the motor chamber 18 essentially completely axially.

[0025] In the third housing part 123, specifically in a housing wall 1234 of the third housing part 123 that separates the electronics chamber 22 from the motor chamber 18, a pressure equalization opening 1235 is formed, which fluidically connects the electronics chamber 22 to the motor chamber 18. A pressure equalization element 32 is arranged at the pressure equalization opening 1235, which is designed to allow gas exchange between the electronics chamber 22 and the motor chamber 18 via the pressure equalization opening 1235, but to prevent the ingress of liquid from the motor chamber 18 into the electronics chamber 22 via the pressure equalization opening 1235.In the present embodiment, the pressure equalization element 32 is a gas-permeable and liquid-impermeable membrane which is arranged directly at the pressure equalization opening 1235 and completely covers it, so that fluid exchange between the electronics chamber 22 and the motor chamber 18 via the pressure equalization opening 1235 can take place exclusively through the membrane.

[0026] On the third housing part 123, specifically on one side of the housing wall 1234 facing the electronics chamber 22 and separating the electronics chamber 22 from the motor chamber 18, several cooling domes 1236 are formed, projecting axially towards the motor electronics 24 arranged in the electronics chamber 22. Furthermore, a cooling dome 1237 is also formed on the common housing wall section 1233 between the intake duct 1239 and the electronics chamber 22.

[0027] In the present embodiment, the impeller 16 and the conveying chamber 14 are configured to form a side-channel conveying unit 26, which is arranged in a known manner to convey a fluid through the conveying chamber 14 when the impeller 16 rotates. The impeller 16 comprises a plurality of impeller blades 161 distributed along its circumference. The conveying chamber 14 comprises a first side channel 141, which is located on a first axial side of the impeller 16 facing away from the electric motor 20 and is formed by the first housing part 121, and a second side channel 142, which is located on a second axial side of the impeller 16 facing the electric motor 20 and is formed by the second housing part 122. The impeller 16 is mounted on a drive shaft 28 rotatably supported in the housing 12.

[0028] The electric motor 20 comprises a motor stator 201, which is mounted in the housing 12, and a motor rotor 202, which is attached to the drive shaft 28. The motor stator 201 comprises a laminated stator body 2011, on which, in the present embodiment, six stator windings 2012 are arranged. The motor rotor 202 is a permanent magnet. The motor stator 201 and the motor rotor 202 interact in a known manner to drive the motor rotor 202, and thus the drive shaft 28, rotationally by appropriately controlling the stator winding 2012. The winding ends 2013 of the stator windings 2012 extend axially through openings 1238 formed in the third housing part 123 into the electronics chamber 22, with a gap between the winding ends 2013 and the third housing part 123 being sealed by a sealing agent 30.

[0029] The motor electronics 24 comprise a circuit board 241 on which a multitude of electronic components (not shown) are arranged. The motor electronics 24 is electrically connected to the winding ends 2013 of the stator windings 212 and configured to control the winding ends 2413 in a known manner to drive the motor rotor 202 and thus the impeller 16. The motor electronics 24 is arranged in the electronics chamber 22 such that the circuit board 241 and / or electronic components arranged on it are in direct thermal contact with the cooling domes 1236, 1237. Advantageously, power semiconductor components of the motor electronics are arranged on those areas of the circuit board 241 that are in direct thermal contact with the cooling domes 1236, 1237, and / or the power semiconductor components are arranged in direct thermal contact with a cooling dome 1236, 1237. Reference symbol list

[0030] 10 Blower 12 Housing 121 First housing part 1211 Outlet nozzle 1212 Outlet opening 1213 Outlet duct 122 Second housing part 1221 Passage 123 Third housing part 1231 Intake nozzle 1232 Intake opening 1233 Common housing wall section 1234 Housing wall 1235 Pressure equalization opening 1236 Cooling domes 1237 Cooling dome 1238 Opening 1239 Intake duct 124 Fourth housing part 14 Conveyor chamber 141 First side channel 142 Second side channel 16 Impeller 161 Impeller blades 18 Motor chamber 181 Flow inlet 182 Flow outlet 20 Electric motor 201 Motor stator 2011 Stator body 2012 Stator windings 2013 Winding ends 202 Motor rotor 22 Electronics chamber 221 Ring-shaped chamber area 24 Motor electronics 241 Circuit board 26 Side channel conveying unit 28 Drive shaft 30 Sealant 32 Pressure equalization element

Claims

1. A blower (10) comprising: - a housing (12) on which an intake opening (1232) and an outlet opening (1212) are formed and which forms a conveying chamber (14), a motor chamber (18) and an electronics chamber (22), the housing (12) being designed such that a fluid can be conveyed from the intake opening (1232) through the motor chamber (18) and the conveying chamber (14) to the outlet opening (1212), - an impeller (16), which is arranged in the conveying chamber (14), the conveying chamber (14) and the impeller (16) being designed such that a fluid is conveyed through the conveying chamber (14) when the impeller (16) rotates, - an electric motor (20) which is arranged in the motor chamber (18) and which is designed to drive the impeller (16) in rotation, and - a motor electronics unit (24) which is arranged in the electronics chamber (22) and which is designed to control the electric motor (20) in order to drive the impeller (16), wherein the housing (12) has a pressure equalization opening (1235) via which the electronics chamber (22) is fluidically connected to the motor chamber (18), characterized in that at the pressure equalization opening (1235) a pressure equalization element (32) is arranged which is designed to allow gas to be exchanged between the electronics chamber (22) and the motor chamber (18) via the pressure equalization opening (1235) and to prevent liquid from infiltrating into the electronics chamber (22) via the pressure equalization opening (1235).

2. The blower (10) according to Claim 1, wherein the motor chamber (18) is arranged fluidically between the intake opening (1232) and the conveying chamber (14).

3. The blower (10) according to one of the preceding claims, wherein a fluidic inlet (181) of the motor chamber (18) and a fluidic outlet (182) of the motor chamber (18) are arranged at different axial heights.

4. The blower (10) according to one of the preceding claims, wherein a housing part (123), which forms a housing wall (1234) separating the electronics chamber (22) from the motor chamber (18), consists of a metal.

5. The blower (10) according to one of the preceding claims, wherein the electronics chamber (22) surrounds the motor chamber (18) radially at least partially.

6. The blower (10) according to one of the preceding claims, wherein on a side of a housing wall (1234) separating the electronics chamber (22) from the motor chamber (18), facing the electronics chamber (22), at least one cooling dome (1236), projecting in the direction of the motor electronics (24), is formed, which is in thermal contact with an electronics component and / or with a board (241) of the motor electronics (24).

7. The blower (10) according to one of the preceding claims, wherein the housing (12) forms an intake duct (1239) comprising the intake opening (1232), such that the intake duct (1239) and the electronics chamber (22) have a shared housing wall portion (1233).

8. The blower (10) according to one of the preceding claims, wherein the conveying chamber (14) and the impeller (16) are designed such that they form a side channel conveying unit (26).

9. The blower (10) according to one of the preceding claims, wherein a motor stator (201) of the electric motor (20) comprises at least six stator windings (2012).

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