Vehicle fan and ventilation system

Abstract

Vehicle fan (10), in particular a heating / cooling system for a vehicle interior, comprising a fan housing (12) having an air inlet (22) and an air outlet (24), wherein a driven fan wheel (14) is provided in the fan housing (12), and a motor control unit (18) for a fan motor (16) and a cooling device (20) for the motor control unit (18), wherein the air outlet (24) has a main flow channel (26), from which a secondary flow channel (28) branches off in the region of the air outlet (24) axially offset from the fan wheel (14), and wherein the cooling device (20) is located on the secondary flow channel (28), is cooled by an air flow in the secondary flow channel (28) and has a heat sink (34) which is in heat-conducting contact with the engine control unit (18) and delimits the secondary flow channel (28) in sections with a heat-transferring surface (36) and which has a plurality of projections and / or fins projecting into the secondary flow channel (28), wherein the air flow in the secondary flow channel (28) passes the cooling device (20), and wherein the fan wheel (14) has additional blades (38) which are designed to suck air from the secondary flow channel (28).

Description

[0001] The invention relates to a vehicle fan, in particular a heating / cooling system for a vehicle interior and further to a ventilation system, preferably an HVAC system for a vehicle.

[0002] Vehicle fans are known from the prior art in which a cooling device for the engine control unit is arranged in the main flow channel of the air outlet. High flow velocities in the flow channel of the air outlet can cause air to swirl around the fins of the cooling device, resulting in noise.

[0003] Furthermore, vehicle fans in vehicle air conditioning systems are known in which the motor control is located away from the vehicle fan for cooling purposes, on another component of the vehicle air conditioning system. This complicates the installation or replacement of the vehicle fan in the air conditioning system.

[0004] Furthermore, DE 195 46 040 A1 discloses a centrifugal blower comprising a turbine driven by an electric motor and a power control device that regulates the electric motor. The electric motor and the power control device are cooled by an air stream that is diverted from a positive pressure area of ​​the centrifugal blower and directed into a negative pressure area.

[0005] Furthermore, DE 195 47 674 A1 discloses a radial fan comprising a housing and an electric motor arranged within a dome-shaped recess in the housing. The electric motor is cooled by a cooling air flow that is guided from a spiral chamber in the housing to the bottom of the recess, through the electric motor, and back into the spiral chamber.

[0006] JP 2002-335 647 A discloses a vehicle fan having a fan housing in which a fan wheel is arranged and having a plurality of air outlets, namely an air outlet for directing air into or out of a vehicle, and an air outlet through which air is directed to a cooling device and through a fan motor.

[0007] Furthermore, EP 1 033 494 A2 discloses a vehicle fan comprising a fan housing with an air inlet opening below an outlet opening. Air is drawn into a spiral chamber through a fan wheel, and the air exits from the spiral chamber through the outlet opening. Part of the drawn-in air is diverted as cooling air, flows through the drive motor, and then re-enters the spiral chamber.

[0008] US 4 428 719 A shows a brushless motor fan unit in which a brushless motor and a centrifugal fan are constructed as a single unit.

[0009] JP 2002-112504 A discloses a brushless motor for a blower for a vehicle air conditioning system.

[0010] The object of the invention is to provide a simply constructed and compact vehicle fan with an improved cooling device for the engine control unit, as well as a ventilation system.

[0011] This object is achieved by a vehicle fan according to the invention as claimed in claim 1. Since the cooling device is arranged in the secondary flow channel, no air turbulence and noise generation occur in the main flow channel. Since the secondary flow channel can be designed such that the flow velocity in it is lower than in the main flow channel, noise generation by the cooling device can be greatly reduced without changing the airflow characteristics in the main flow channel.

[0012] The cooling air is directed through the bypass duct into the fan motor for cooling. This allows for easy cooling of the fan motor and a compact design of the vehicle fan. To enable airflow in the bypass duct due to a pressure difference, the bypass duct is connected to the air inlet.

[0013] In order to ensure good cooling performance of the cooling device for the engine control, the cooling device can be arranged in the secondary flow channel upstream of the engine.

[0014] The cooling device has a heat sink that is in thermally conductive contact with the engine control unit and that defines sections of the secondary flow channel with a heat-transferring surface. The heat sink has several projections and / or fins that extend into the secondary flow channel. The thermally conductive contact is achieved via a solid-state bridge.

[0015] The cooling device of the engine control unit can be arranged opposite one end face of the engine. Alternatively, the cooling device of the engine control unit can be arranged radially next to the engine. In this way, the design of the vehicle fan can be adapted to the available installation space in the vehicle.

[0016] The fan impeller can be designed as a disc impeller or a spoked impeller. A spoked impeller easily utilizes the pressure difference between the air inlet and outlet to generate flow in the bypass duct, while a disc impeller simply protects the engine from fluids drawn into the air intake.

[0017] The vehicle fan is preferably a radial fan. This allows, for example, a higher pressure difference to be created between the air inlet and air outlet.

[0018] The invention is further achieved by a ventilation system, preferably an HVAC system, for a vehicle, with a vehicle fan as described above.

[0019] Further features and advantages of the invention will become apparent from the following description and the accompanying drawings, to which reference is made. In the drawings: - Fig. 1 is a schematic sectional view of a vehicle fan according to a first embodiment not according to the invention; - Fig. 2 is a schematic sectional view of a vehicle fan according to a second embodiment of the invention; - Fig. 3 an exploded view of the housing of the vehicle fan from Fig. 2; - Fig. 4 a perspective view of the vehicle fan according to Fig. 2; and - Fig. 5 a vehicle fan according to a third embodiment not according to the invention.

[0020] Fig. Figure 1 shows a schematic view of a vehicle fan 10 designed as a radial fan with a fan housing 12, a fan wheel 14, and a fan motor 16 that drives the fan wheel 14. An electronic motor control unit 18, which is cooled by a cooling device 20, is provided to control the fan motor 16.

[0021] The fan motor 16 accommodated in the fan housing 12 is designed as an electric motor in the embodiment shown and has a motor shaft 32 which is connected to the fan wheel 14 and enables the drive of the fan wheel 14.

[0022] An air inlet 22 and an air outlet 24 are provided in the fan housing 12, with the air outlet comprising a main flow channel 26 and a secondary flow channel 28. The secondary flow channel 28 is designed as a branch from the main flow channel 26 and, in a first region, extends away from the main flow channel 26 approximately perpendicular to the main flow direction. In a second region, the secondary flow channel extends past the fan motor 16 to the air inlet 22.

[0023] The secondary flow channel 28 extends from the main flow channel 26 to the fan motor 16 and is connected to the air inlet 22 via fan wheel openings 30 between the spokes of the fan wheel 14. The pressure difference between the air outlet 24 and the air inlet 22 increases the flow velocity in the secondary flow channel 28.

[0024] In the first embodiment, the fan wheel 14 is designed as a spoked wheel, with fan wheel openings 30 extending between the spokes essentially from the hub to the wheel rim of the fan wheel 14. However, smaller fan wheel openings 30 can also be provided, extending only over a partial area between the hub and the wheel rim.

[0025] The main blades of the fan wheel 14 are arranged on the wheel rim on the side of the fan wheel 14 facing away from the fan motor 16.

[0026] The cooling device 20 of the engine control unit 18 is positioned in the secondary flow channel 28 upstream of the fan motor 16, opposite a front side of the fan motor 16. The air flow thus first cools the cooling device 20 of the engine control unit 18 and then the fan motor 16.

[0027] The cooling device 20 has a heat sink 34, which is in thermally conductive contact with the engine control unit 18 and, with a heat-transfer surface 36, partially defines the secondary flow channel 28. The heat sink 34 has a plurality of projections and / or fins extending into the secondary flow channel 28, which enlarge the heat-transfer surface 36.

[0028] When the vehicle fan 10 is in operation, the fan impeller 14 is driven by the fan motor 16 and draws air from the air inlet 22 to the air outlet 24 into the main flow channel 26 and the secondary flow channel 28. The air flow through the secondary flow channel 28 passes the heat sink 34 of the cooling device 20 of the engine control unit 18 and through the fan motor 16 and then enters the air inlet 22 of the fan housing 12 through the fan impeller openings 30.

[0029] The secondary flow channel 28 is designed such that the flow velocity of the air flow through the secondary flow channel is reduced compared to the flow velocity in the main flow channel 26. In this way, excessive noise generation at the heat sink 34 or at the fan motor 16 due to air turbulence is prevented.

[0030] Fig. 2 shows a second embodiment of a vehicle fan 10, wherein the second embodiment differs from the first embodiment essentially in the design of the fan wheel 14.

[0031] The fan wheel 14 is designed as a disc wheel and does not have fan wheel openings 30 between the hub and the wheel rim. This protects the cooling device 20 and the fan motor 16 from liquid droplets in the air flow. Liquid droplets are transported by the air flow in the main flow direction and are thus deflected by the fan wheel 14 from the air inlet 22 to the air outlet 24 in accordance with the main flow direction. However, due to the inertia of the liquid droplets, they do not reach the secondary flow channel 28.

[0032] On the side of the wheel rim of the fan wheel 14 facing the fan motor 16, additional blades 38 are provided which are designed to suck air from the secondary flow channel 28 and transport it to the air outlet 24 and thus cause the air flow in the secondary flow channel.

[0033] Fig. 3 shows an exploded view of the vehicle fan from Fig. 2. The fan housing 12 comprises a first housing part 40 in which the fan wheel 14 and the air inlet 22 and the air outlet 24 are provided.

[0034] A second housing part 42 is connected to the first housing part 40 and essentially forms the housing section that surrounds the fan motor 16.

[0035] A third housing part 44 is placed on the second housing part 42 and closes the fan housing 12 as a cover. The motor control unit 18 with the cooling device 20 is provided on the third housing part 44.

[0036] In the embodiment shown, the secondary flow channel 28 extends through all three housing parts 40, 42, 44. However, it is also possible for the secondary flow channel 28 to be formed essentially in one or two housing parts 40, 42, 44.

[0037] Fig. Figure 4 shows a perspective view of the vehicle fan 10, with a portion of the second housing part 42 cut away to show the fan wheel 14. The main blades and auxiliary blades 38 can be seen on the fan wheel 14.

[0038] The additional blades 38 are arranged in the circumferential direction between two main blades.

[0039] The secondary flow channel 28 and the additional blades 38 are designed such that the flow velocity in the secondary flow channel 28 is lower than in the main flow channel 26. In this way, air noise during the flow through the cooling device 20 is reduced.

[0040] Fig.Figure 5 shows a further embodiment, which is essentially analogous to the first embodiment. However, the motor control unit 18 with the cooling device 20 is not arranged opposite the end face of the fan motor 16, but is located radially next to the fan motor 16 in the first region of the secondary flow channel 28.

[0041] Alternatively, it is also possible for the motor control unit 18 with its cooling device 20 to be arranged in a separate secondary flow channel 28 parallel to the secondary flow channel 28 of the fan motor 16.

[0042] The various features of the different embodiments can also be advantageously combined with one another in other ways.

[0043] The embodiments shown in the figures are each designed as radial fans. However, it is also possible for the vehicle fans to be designed as axial or tangential fans.

Claims

[1] Vehicle fan (10), in particular a heating / cooling system for a vehicle interior, comprising a fan housing (12) having an air inlet (22) and an air outlet (24), wherein a driven fan wheel (14) is provided in the fan housing (12), and a motor control unit (18) for a fan motor (16) and a cooling device (20) for the motor control unit (18), wherein the air outlet (24) has a main flow channel (26), from which a secondary flow channel (28) branches off in the region of the air outlet (24) axially offset from the fan wheel (14), and wherein the cooling device (20) is located on the secondary flow channel (28), is cooled by an air flow in the secondary flow channel (28) and has a heat sink (34) which is in heat-conducting contact with the engine control unit (18) and delimits the secondary flow channel (28) in sections with a heat-transferring surface (36) and which has a plurality of projections and / or fins projecting into the secondary flow channel (28), wherein the air flow in the secondary flow channel (28) passes the cooling device (20), and wherein the fan wheel (14) has additional blades (38) which are designed to suck air from the secondary flow channel (28). [2] Vehicle fan (10) according to claim 1, characterized bythat the cooling device (20) of the engine control unit (18) is arranged in the secondary flow channel (28) upstream of the fan motor (16). [3] Vehicle fan (10) according to claim 1 or 2, characterized by that the cooling device (20) of the motor control unit (18) is arranged opposite an end face of the fan motor (16). [4] Vehicle fan (10) according to claim 1 or 2, characterized by that the cooling device (20) of the engine control unit (18) is arranged in the radial direction next to the fan motor (16). [5] Vehicle fan (10) according to one of the preceding claims, characterized by that the fan wheel (14) is designed as a disc wheel or as a spoked wheel. [6] Vehicle fan (10) according to one of the preceding claims, characterized by that the vehicle fan (10) is a radial fan. [7] Ventilation system, preferably an HVAC system, for a vehicle, comprising a vehicle fan (10) according to one of the preceding claims.

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