System for cooling a propeller drive having multiple electric machines

Abstract

A cooling system for a drive propeller arrangement having a plurality of electric machines is disclosed. One aspect of the invention relates to a cooling system (11) for a drive arrangement having a plurality of electric machines (10), the cooling system comprising: a hydraulic circuit (11H) for a coolant, comprising: cooling components in a gearbox (12) of the drive arrangement, for cooling the gearbox; and an air / coolant heat exchanger (112), comprising cooling walls forming a passage for circulating coolant to cool it; an air cooling circuit (11A), comprising: a plurality of fans (110) rotatably connected to the gearbox (12); a cooling section between the cooling walls of the air / liquid heat exchanger, wherein air drawn in and pushed by the fans circulates by sweeping over the cooling walls to cool them.

Description

Technical Field

[0001] The technical field of this invention is a propeller-driven propulsion system, which includes a drive unit with multiple motors and a cooling system thereof.

[0002] This invention relates to the cooling of drive units having multiple motors, and in particular to the cooling of the coolant in the drive unit. Background Technology

[0003] Devices for driving at least one propeller are known, including an electric motor or heat engine and a gearbox that drives or is driven by the electric motor and the propeller or turbine.

[0004] The motor can be an electric motor that drives a gearbox or a generator driven by a gearbox, for example, in a drive unit with multiple hybrid propulsion motors or a motor with both motor and generator modes.

[0005] For vertical takeoff and landing (VTOL) type aircraft, devices for driving at least one propeller are particularly known. These drive devices may include multiple motors and gearboxes driven by the motors, which are electric motors.

[0006] An electric propeller drive unit may include an air / oil exchanger for cooling the oil circulating in the gearbox, which can also cool the motor, particularly the electronic components. The air / oil exchanger may be cooled by a fan assembly comprising a propeller driven by an electric motor.

[0007] There are also hybrid or thermal propeller propulsion drive systems, which include drive units for generating electrical energy, including an electric motor. In this case, the motor generates electricity from energy via a generator coupled to a gearbox driven by a heat engine. If there is an oil leak or a defective fan assembly, the heat engine and gearbox should be large enough to generate sufficient heat for landing. However, the generator may not have enough electrical energy and may switch to a failure mode when the temperature exceeds a predetermined level, posing a risk of battery discharge.

[0008] For electric or hybrid propeller drives, in the event of a motor failure, the other motors can move in degraded mode during landing. Motors, especially their power units and power components, heat up rapidly if not cooled, and switch to a safe mode once they exceed a certain temperature. The time between the moment of failure and the motor switching to safe mode may be too short to allow for landing. Therefore, an independent cooling system could be developed for each motor, but this would incur additional weight and cost.

[0009] Therefore, there is a need for a system for cooling a drive unit with multiple motors, which can improve cooling by providing cooling in the event of a failure, while optimizing the weight and additional costs of the machine. Summary of the Invention

[0010] The present invention provides a method for solving the above-mentioned defective motor or fan problems, which makes it possible to have a redundant cooling system by having the oil route cooled by multiple fans, thereby making it possible for the air and oil cooling circuits to continue to be cooled in the event of a fan failure.

[0011] One aspect of the present invention relates to a cooling system for a drive device having multiple motors, the cooling system comprising:

[0012] - A hydraulic circuit for the coolant, including:

[0013] - The cooling components in the gearbox of the drive unit are used to cool the gearbox, and

[0014] - An air / coolant heat exchanger, including cooling walls that form channels for circulating coolant to cool it.

[0015] - Air cooling circuit, including:

[0016] - Multiple fans, rotatably connected to the gearbox,

[0017] - A cooling section between the cooling walls of an air / liquid heat exchanger, in which air drawn in and propelled by a fan circulates by sweeping across the cooling walls to cool them.

[0018] Because of this invention, and due to the presence of multiple fans ensuring the coolant is cooled in the heat exchanger, at least one additional fan will operate to cool the coolant even in the event of a motor failure. Furthermore, there is no additional motor to drive the fans; that is, there is a dedicated motor for driving the fans. Moreover, since the gearbox is cooled by a hydraulic system, and the fluid in the hydraulic system is cooled by redundant ventilation, the gearbox experiences less heating, which reduces its inertia, thereby reducing its volume and / or extending its service life.

[0019] In addition to the features just mentioned in the preceding paragraphs, a cooling system according to one or more embodiments of the present invention may have one or more additional features mentioned in the following paragraphs, either individually or in any technically permissible combination.

[0020] According to one embodiment, the cooling component in the gearbox of the drive unit used to cool the gearbox is also a lubrication component of the embedded mounting box.

[0021] According to one embodiment, the air cooling circuit includes at least one fan for each motor, and each fan is rotatably connected to the corresponding motor. In fact, each motor has one fan connected to it, thus ensuring that the coolant is cooled in the heat exchanger, and even in the event of a motor failure, at least one other fan will work with the other motor to cool the coolant.

[0022] According to one embodiment, the air cooling circuit includes machine air ducts vented by a fan for cooling one of the motors. This ensures that the motor is always cooled by air ventilation in the event of an oil leak. Furthermore, in combination with the aforementioned embodiments, this allows the air ventilation of the motor to be used for both the motor and the heat exchanger.

[0023] According to an example of this implementation, the machine air duct is part of the power electronics assembly of the electric motor to cool the components of the power electronics assembly. This makes it possible for the power electronics assembly of the motor to be constantly cooled by air ventilation.

[0024] According to an example of this implementation, the machine's air ducts allow for the cooling of the motor's stator windings. This ensures that the motor windings are always cooled by air ventilation unless the motor is defective, in which case cooling the windings is no longer necessary.

[0025] According to one embodiment, the air cooling circuit includes an air inlet that passes through the front wall of the drive unit housing to allow air to enter the air cooling circuit.

[0026] According to an example of this embodiment, the air intake is axial relative to the axis of the propeller of the propulsion drive system.

[0027] The term "axial inlet" refers to the inlet that passes axially through the wall relative to the axis of the propeller of the propulsion drive system.

[0028] According to an example of this embodiment, the air inlet is radial. The term "radial inlet" means that it passes radially through the wall relative to the axis of the propeller.

[0029] According to an example of this embodiment, the air cooling circuit includes an air inlet surrounding a gearbox having multiple motors as drive units. The air inlet can be axial, radial, or both.

[0030] According to an example of this implementation, the air cooling circuit includes one air inlet for each motor.

[0031] According to an example of this embodiment, the air cooling circuit includes a guide duct for each air inlet to circulate air from the air inlet to at least one motor. This allows for improved airflow and thus improved cooling of the air cooling circuit.

[0032] According to an example of this embodiment, each air inlet is angularly adjacent to the two motors, and each guide duct includes two channels, each extending from one of the two adjacent motors to the upstream channel from the air inlet. This allows the motors to be cooled at least by air from the other guide ducts, in the case of guide ducts.

[0033] According to one embodiment, the air cooling circuit includes exchanger ducts for directing air from at least one fan to an exchanger. This allows air to be directly directed from the fan to the exchanger, thereby improving air / coolant heat exchange.

[0034] According to one embodiment, the hydraulic circuit includes motor component piping for cooling one of the motors. In the case of an air-cooled circuit including motor air piping, cooling can be performed better than air ventilation, or it can be redundant with air cooling. The motor component piping differs from the air / liquid heat exchanger of the hydraulic circuit. The motor component piping can cool machine components, even though the piping can be further cooled by air. Although the air / liquid heat exchanger is designed to cool its hydraulic fluid, the heat exchanger may contact the motor component to cool that component, but it is not part of the machine. Therefore, the air / liquid heat exchanger is external to each motor.

[0035] According to an example of this embodiment, the motor component conduit includes a portion of the power electronics assembly of the electric motor to cool multiple components of the power electronics assembly. This results in better cooling compared to ventilation. Furthermore, when combined with the aforementioned example of an embodiment where the power electronics assembly is cooled by ventilation, this provides cooling redundancy and allows for cooling in the event of fan failure or oil leakage.

[0036] According to an example implementation of this embodiment, the hydraulic circuit is arranged to cool the biased power electronics of the motor of the electric motor.

[0037] The term "biased power electronics of an electric motor" refers to a power unit that supplies power to the electromagnetic components (rotor and stator) of an electric motor, which is not directly fixed to the housing supporting the electromagnetic components of the motor. For example, the power electronics unit of each motor is combined in the power unit of the propulsion system, which is fixed to the housing of the propulsion system.

[0038] According to an example of this embodiment, the motor components allow for cooling of the motor stator windings. This results in better cooling compared to ventilation. Furthermore, when combined with the aforementioned example of an embodiment where the windings are cooled by ventilation, this provides cooling redundancy and allows for cooling in case of fan failure or oil leakage.

[0039] According to one embodiment, the hydraulic circuit's conduits for each motor component are located in the stator and / or a portion of the motor's power electronics assembly to cool components of the power electronics assembly. According to one example, each motor may include a lubrication circuit in the rotor, separate from the hydraulic circuit, to lubricate the motor's bearings.

[0040] According to one embodiment, the coolant circuit includes a coolant tank for supplying coolant to the gearbox and a pump for circulating coolant from the gearbox to the coolant tank via an air / coolant exchanger.

[0041] Another aspect of the present invention relates to a propeller propulsion drive system having multiple motors, comprising:

[0042] - Drive unit, including:

[0043] - Multiple motors, including rotors, stators, and housings.

[0044] - Gearbox, including:

[0045] Each motor has one gear, and each gear meshes with the motor's rotor.

[0046] • At least one propulsion wheel, which meshes with each rotor of the motor via gears, and

[0047] -A cooling system based on one of the above characteristics.

[0048] A propeller propulsion drive system with multiple motors according to one or more embodiments of the present invention may have one or more additional features mentioned in the following paragraphs, individually or in any technically permissible combination.

[0049] According to one implementation, each motor also includes power electronics components.

[0050] According to the example, the power electronics for each motor are located between the fan and the rotor.

[0051] According to another example, the power electronics are located between the rotor and bearing supports, or before or between the stator and housing of the motor. For example, the electronics unit is located between the machine's air ducts.

[0052] According to one embodiment, the drive system includes an electronic unit that includes a power electronics unit for each motor, and a hydraulic circuit that is arranged to cool the electronics unit.

[0053] According to an example of this implementation, the electronic unit comes into contact with a heat exchanger to cool it.

[0054] According to the examples of the two aforementioned embodiments, the air cooling circuit includes an exchanger inlet duct in which an electronic unit is located, and the exchanger inlet duct includes an open end connected to the heat exchanger.

[0055] According to this example implementation, the exchanger intake duct includes one channel for each fan, and each channel includes an opening connected to the motor.

[0056] According to one implementation, the air / liquid heat exchanger is separated from and removed from each motor (the term "separated and removed" means that the heat exchanger is not in contact with the motor).

[0057] According to one embodiment, the air / liquid heat exchanger is separated from and removed from the stator and rotor of the motor. In an example of this embodiment, the electronics unit contacts the heat exchanger to cool it.

[0058] According to one embodiment, the drive unit includes a housing for accommodating a gearbox and a plurality of motors, and the air cooling circuit includes at least one air inlet passing through the housing to draw in external air by a fan, as well as an exhaust port and an air outlet opposite to the air inlet.

[0059] According to one embodiment, each motor includes a corresponding fan that rotates integrally with the rotor of the corresponding motor.

[0060] According to an alternative to the foregoing embodiment, the gearbox includes at least two fans, and each fan is connected to the rotor of the motor via a fan gear. The fan gear thus includes a gear that is part of the fan and meshes with a gear in the gearbox, such as an intermediate gear, or directly with the drive wheel. According to an example, the gearbox includes one fan per motor.

[0061] According to one implementation, the system includes a clutch between each motor and the gearbox.

[0062] In one implementation, for each motor, the gearbox includes an intermediate machine wheel between the rotor and the drive wheel. This allows for an increase in the speed or torque at the drive wheel relative to the motor.

[0063] A better understanding of the invention and its various applications will be gained by reading the following description and examining the accompanying drawings. Attached Figure Description

[0064] These figures are shown for informational purposes only and are not intended to limit the invention.

[0065] Figure 1 A block diagram of an example of a vertical takeoff and landing aircraft including a propeller propulsion drive system with multiple motors, according to a first or second embodiment of the present invention, is shown.

[0066] Figure 2A block diagram of an axial section of a propeller propulsion drive system having multiple motors is shown, including a cooling system according to a first example of a first embodiment of the invention.

[0067] Figure 3 A block diagram showing an axial section of a propeller propulsion drive system having multiple motors including a cooling system, according to a second example of a first embodiment of the present invention, is provided.

[0068] Figure 4a A block diagram showing a three-dimensional view of the motors of a propeller-propulsion drive system having a first or second example of this embodiment is provided.

[0069] Figure 4b It shows Figure 4a A partial block diagram of the axial half-section view of the motor.

[0070] Figure 5 It shows that according to having Figure 3 A top-view block diagram of an example propeller-propulsion drive system with multiple motors.

[0071] Figure 6 A block diagram showing an axial section of a propeller propulsion drive system having multiple motors including a cooling system, according to a third example of this embodiment of the invention, is provided.

[0072] Figure 7 A block diagram showing a three-dimensional view of a multi-channel pipe of a cooling system according to a third embodiment of the present invention is provided.

[0073] Figure 8 A block diagram showing an axial section of a propeller propulsion drive system having a cooling system including an example according to a second embodiment is shown.

[0074] Figure 9 A block diagram of an axial top view of a propeller propulsion drive system with multiple motors, the motors including a cooling system according to a second embodiment, is shown. Detailed Implementation

[0075] Figure 1 A block diagram representation of vertical takeoff and landing aircraft A is shown.

[0076] The vertical takeoff and landing aircraft A also includes a transport body 2, which includes a fuselage, four wings 3 extending from the fuselage, and a cabin 4 at the front of the fuselage. In addition, at each end of the wings 3, there is a propeller propulsion drive system with multiple motors 1.

[0077] Of course, the vertical takeoff and landing aircraft A is an example, which may include a propeller propulsion drive system with one or more motors 1, and may be located in other locations, particularly in the fuselage or wing 3.

[0078] Figure 1 An enlarged schematic diagram of a propeller propulsion drive system is shown, which has multiple motors 1, hereinafter referred to as drive system 1. Drive system 1 includes a drive unit with multiple motors, hereinafter referred to as drive unit. The drive unit here includes three motors 10, but may include only one, two, or more than three, such as four motors 10. Each motor 10 includes a rotor 100, the rotor 100 including an axially extending rotor shaft 1002, a stator 102 including windings around the rotor 100, and a housing 104 surrounding and supporting the stator 102, the housing 104 including two bearings at both ends of the rotor to axially support the rotor shaft 1002, as described in detail below. Figure 2 As shown.

[0079] Figure 2 Showing Figure 1 The block diagram shows the drive system 1. This block diagram, in axial cross-section, shows the motor 10. The motors 10 are shown aligned in the block diagram, but in this example, they are distributed around the axis of rotation of the propeller. Here, the motors are arranged regularly around the axis of rotation of the propeller. Therefore, each axis of rotation of the rotor of each machine is located at the vertex of an equilateral triangle to reduce size.

[0080] The drive unit also includes a gearbox 12 that meshes with each motor 10.

[0081] In this example, the drive system 1 also includes a clutch 14 for each motor 10 between the gearbox 12 and the rotor shaft 1002 of the corresponding motor 10. That is, the clutch can separate the rotor shaft 1002 of the corresponding motor 10 from the gearbox 12 in the disengaged position, and connect the rotor shaft 1002 of the corresponding motor 10 to the gearbox 12 in the engaged position.

[0082] The gearbox 12 includes a propulsion output shaft 120, which includes the rotating shaft of the propeller 16, and is connected to each rotor shaft 1002 by gears when the corresponding clutch 14 is in the engaged position.

[0083] like Figure 5 As shown, the gears of the gearbox 12 may include intermediate gears between the propulsion output shaft 120 and the gears directly connected to the rotor shaft of the respective machine. For example, the gearbox includes one intermediate machine wheel 122 for each motor. These are connected to the gears connected to the motor rotor shaft 1002 and the propulsion wheel 124 rotatably connected to or directly driving the propulsion output shaft 120.

[0084] The drive system 1 also includes at least one propeller 16 driven by a propulsion wheel of the engagement device 12 of the drive unit, here being a single propeller comprising four blades. Of course, the propeller may include fewer or more than four blades, for example, between two and ten blades. The drive system 1 may include, for example, more than one propeller, such as two coaxial propellers.

[0085] The drive system 1 includes a cooling system 11 for cooling the drive device according to the first example of the first embodiment.

[0086] The cooling system 11 includes a hydraulic circuit 11H for the coolant and air cooling circuit 11A.

[0087] The hydraulic circuit 11H includes cooling components in the gearbox 12 for cooling.

[0088] The hydraulic circuit 11H includes an air / coolant heat exchanger 112, a coolant tank 114 supplying coolant to the gearbox, and a pump 116 circulating coolant from the gearbox 12 to the coolant tank 114 via the air / coolant heat exchanger 112. According to another example, the pump circulates coolant from the tank 114 through the heat exchanger and the coolant tank 114 back to the gearbox 12. The air / liquid heat exchanger 112 is designed to cool its hydraulic fluid. The air / liquid heat exchanger 12 is external to each motor 10, but may contact a portion of the motor 10 to cool that portion without needing to be part of the motor 10.

[0089] In this embodiment, the coolant is oil, but it can also be another type of coolant.

[0090] The exchanger 112 includes cooling walls formed in a known manner for channels for circulating coolant, which are cooled by air circulating between these channels.

[0091] In this embodiment, the cooling components in the gearbox 12 of the hydraulic circuit 11H are located inside the gearbox 12, thereby allowing the oil to come into direct contact with the gears for further lubrication.

[0092] In this example, the drive system 1 also includes a housing 18, which contains a gearbox 12, a motor 10, and a cooling system 11. The cooling system 11 includes a hydraulic circuit 11H for coolant and an air cooling circuit 11A. The gearbox 12, motor 10, and exchanger 112 of the hydraulic circuit 11H are fixed to the housing 18.

[0093] The air cooling circuit 11A includes multiple fans 110 that are rotatably connected to the gearbox 12.

[0094] Specifically, in this first embodiment, the air cooling circuit 11A includes a fan 110 for each motor 10. Each fan is rotatably connected to the rotor shaft 1002 of the rotor 100 of the corresponding motor 10. Here, each fan 110 is directly rotatably connected to the rotor 100 and includes the same rotating shaft.

[0095] Therefore, in this first embodiment, each fan can draw in or expel air to circulate the air in the housing 18 to cool the motor 10.

[0096] Furthermore, in this first embodiment, the housing 18 includes an air inlet 18A surrounding the gearbox 12 to allow external air to enter the housing 18. The air inlet 18A is therefore also part of the air cooling circuit 11A and here is an axial air inlet 18A located on the front wall of the housing between the propeller 16 and the gearbox 12, but the air inlet can also be radial, for example in the wall surrounding the motor housing.

[0097] The air circulating in the drive system is indicated by arrows. Air is drawn in through intake port 18A by fan 110, sweeps across the surface of gearbox 12, cools each motor 10, and then sweeps across the walls of air / coolant exchanger 112, which form channels for coolant (oil) circulation. Finally, the air escapes through one or more rear axial openings, in this case a single rear axial opening. The term "rear" refers to the portion of the drive system opposite the propeller, and therefore located at the front.

[0098] Figure 3 A second example of a first embodiment of the cooling system of the present invention is shown. In this example, the air cooling circuit 11A includes a front guide duct 180A for each motor 10, each front guide duct 180A extending axially through the housing 18 to the corresponding motor 10 from an air inlet 18A. Such guide ducts can improve air heat exchange between the motors. In particular, in this example, each air inlet is angularly adjacent to the two motors 10 by forming an angle between them, and each guide duct includes two channels 1800A extending from the air inlet to each of the two adjacent motors 10.

[0099] Figure 5 It shows having Figure 3 A top view of the drive unit of a multi-motor propeller-driven system, where the channel 1800A of the duct 180A can be considered as a dashed line. That is, each motor 10 receives air from two intakes circulating through two channels. This allows air to be drawn in through another guide duct in the event of a duct blockage.

[0100] Of course, there may be a pipe with a single channel for connecting a dedicated air inlet to a single motor 10, but if the pipe or air inlet is blocked, the airflow rate drawn in by the dedicated fan for the motor will be insufficient to cool the motor.

[0101] To improve the cooling of the motor 10 in these two examples of the first embodiment, the air cooling circuit 11A includes at least one motor air duct 110A for each motor 10. Each motor 10 therefore includes a machine air duct 110A.

[0102] Figure 4a A perspective view of the motor 10, viewed from the rear, is shown, in which the motor air duct 110A can be seen. Figure 4b A block diagram of the axial half-section of the motor 10 is shown.

[0103] Each motor 10 includes a cylindrical outer wall 114A surrounding a machine housing 104. A machine air duct 110A is defined between the machine housing 104 and the cylindrical outer wall 114A.

[0104] In the second example of this embodiment, the machine air duct 110A is connected to two guide ducts 18A.

[0105] In these examples of this embodiment, each motor 10 includes a radially extending front bearing support 101 and includes one of two bearings, here a roller bearing 1011, through which the rotor shaft 1002 passes. The front bearing support 101 thus closes the air gap between the rotor 100 and the stator 102. Here, the front bearing support 101 is mounted on the machine housing 104.

[0106] Furthermore, in these examples of this implementation, each motor 10 includes Figure 4b The visible rear bearing support 103, extending radially, includes a support plate 1030 and a bearing 1031, which is a roller bearing, particularly a ball bearing through which the rotor shaft 1002 passes. The rear bearing support 103 is fixed to the machine housing 104, which in turn is fixed to the housing 18.

[0107] In these examples of the implementation, each motor 10 includes a mounting bracket 1040 extending from the housing 104 to be secured to the housing 18. In this example, both the front bearing support 101 and the rear bearing support 103 include mounting brackets 1040 that extend radially through the housing 104 to be secured to the housing 18.

[0108] In these examples of the implementation, each motor 10 also includes a power electronics assembly 109. In this example, the power electronics assembly 109 is located between the fan 110 and the rotor 100, but it may also be located between the rotor 100 and the front bearing support 101 or around the motor 10.

[0109] Furthermore, in both examples of this embodiment, each fan 110 includes a set of outer blades 1100 and an intermediate crown 1102, the set of outer blades 1100 extending radially outward from the intermediate crown 1102 relative to the rotation axis X of the rotor shaft 1002.

[0110] The outer blades 1100 of this group rotate toward the machine air duct 110A.

[0111] Furthermore, in both examples of this first embodiment, the machine air duct 110A includes fins 1104A extending axially along the machine housing 104, forming a plurality of cooling channels between them. Each fin 1104A extends from the machine housing 104 to cool it and thus the stator and thus the stator windings to increase its efficiency.

[0112] The support plate 1030 also includes a set of internal blades 1032, one of which is in Figure 4b As can be seen in the image. Each internal blade 1032 is bent and secured to the housing 18 and extends toward the duct 110A to guide air ventilated by the fan 110 in multiple channels of the machine air duct 110A.

[0113] Figure 6 A cooling system 11 according to a third embodiment is shown.

[0114] The cooling system 11 of the third example according to the first embodiment is the same as that of the second example, except that the power electronics unit 109 of each motor 10 is offset and combined together in the power electronics unit 19, and the air ventilation duct 11A also includes an exchanger intake duct 119 for guiding air from at least one fan 110 to the exchanger 12.

[0115] Here, in this example, the power electronics unit 19 is located in the exchanger intake duct 119 next to the exchanger 12 so that the power unit can be cooled by the air cooling circuit 11A and the hydraulic circuit 11H.

[0116] The power electronics unit 19 may include fins and openings through it to improve its cooling; these openings may be machine air ducts. Additionally, the exchanger intake duct 119 includes a channel 119A for each fan 110. Figure 7A perspective block diagram of the exchanger intake duct 119 is shown. The arrows indicate the direction of air circulation in channel 119A. This exchanger intake duct 119 can also be installed on the two examples mentioned earlier.

[0117] Figure 8 and Figure 9 Block diagrams showing axial cross-sectional views and front axial views of the propeller drive system 1' are provided. The propeller drive system 1' includes a cooling system 11' different from the third example of the first embodiment, wherein the gearbox 12' includes a fan 110' of an air cooling circuit 11A', and wherein the hydraulic circuit 11H' includes a conduit 110H for cooling at least one motor component of one of the motors 10. Therefore, the propeller drive system 1' includes a fan gear 121 for each fan, as shown... Figure 9 As shown, each fan is connected to the propulsion wheel 122. The fan gear 121 here includes an intermediate gear 1210 that meshes with the gear of the fan 110'.

[0118] In this example embodiment, the air cooling circuit 11A′ includes one fan 110′ for each motor, just like in the first embodiment, but may include only two or more of them.

[0119] The hydraulic circuit 11H′ here includes a motor component pipe 110H for each machine, wherein... Figure 8 Only two stators 102 are shown, each for cooling the corresponding motor 10. Particularly in this example, the hydraulic circuit 11H′ includes a second motor component passing through the power electronics unit 19, which also allows for cooling. In this example, the motor component conduit 110H is located between the outlet of the heat exchanger 112 and the inlet of the oil tank 114, but according to another example, the coolant circulates in the opposite direction between the inlet of the pump 116 and the outlet of the heat exchanger 112. In both examples, the cooling fluid (here, oil) is thus cooled in the heat exchanger 112 before circulating in the motor component conduit 110H.

[0120] Of course, according to the embodiments not shown, in other examples of the first embodiment, the hydraulic circuit 11H′ can be the same as one of these two examples. In particular, in the example of the electronic unit 109 located in the motor housing 104, the machine component conduit can cool the electronic unit 109 through the machine housing 104, or include a circuit that contacts the support diffuser of the electronic unit 109 through the machine housing 104.

[0121] Furthermore, according to another example not shown, the air cooling circuit 11A′ of this second embodiment may not have the exchanger intake duct 119 as in the first or second example of the first embodiment. Of course, in this second embodiment, the power electronics components may be integrated into each motor as in the first or second example of the first embodiment, or combined together to form a power electronics unit 19.

[0122] Furthermore, according to another example not shown, the air cooling circuit 11A' of the second embodiment may not have the guide pipe 180A of the first example of the first embodiment.

[0123] Furthermore, according to another example not shown, the air cooling circuit 11A' of the second embodiment may include a fan 110 of the motor 10 as in the example of the first embodiment.

[0124] In these examples of both implementations, the motor is an electric motor, but it may also include a generator mode driven by a gearbox, such as in the case where the propeller propulsion drive system is hybrid, and also includes a heat engine that drives the gearbox.

[0125] In these examples of both implementations, the motor is an electric motor, but it could also be a generator of an energy-generating system whose gearbox would be driven by a heat engine, such as a gas turbine, a thermal piston engine, or a propeller in generator mode.

[0126] According to an embodiment not shown, the propeller propulsion drive system also includes a fuel cell, whose air cooling circuit and / or hydraulic circuit enable cooling of the fuel cell. For example, the fuel cell is integrated into the housing 18.

[0127] Of course, in all these examples, the propeller 16 can also help ventilate the air entering the housing 18 of the drive unit 1 or 1'. The drive unit 1 or 1' may include more than one propeller 16, such as two propellers.

[0128] Unless otherwise stated, the same element appearing in different figures has a unique reference numeral.

Claims

1. A cooling system (11, 11') for a drive unit (1, 1') having multiple motors, the cooling system comprising: Multiple motors (10) including rotors (100); The gearbox (12) includes: one gear for each motor (10), each gear meshing with the rotor (100) of the corresponding motor (10); The hydraulic circuit (11H, 11H') for the coolant includes: The cooling components in the gearbox (12, 12') of the drive unit are used to cool the gearbox, and An air / coolant heat exchanger (112) includes cooling walls that form channels for circulating coolant to cool it. o Air cooling circuit (11A, 11A') includes: Multiple fans (110, 110') are rotatably connected to the gearbox (12, 12'). The cooling section between the cooling walls of the air / coolant heat exchanger, wherein air drawn in and propelled by the fans (110, 110') circulates by sweeping across the cooling walls to cool them.

2. The cooling system (11, 11') according to claim 1, wherein, The air cooling circuit (11A) includes at least one fan for each motor, and each fan is rotatably connected to the corresponding motor.

3. The cooling system (11, 11') according to any one of the preceding claims, wherein, The air cooling circuit (11A, 11A') includes at least one machine air duct (110A) ventilated by the fans (110, 110') for cooling at least one motor (10).

4. The cooling system (11, 11') according to claim 3, wherein, The at least one machine air duct (110A) is part of the power electronics assembly (109) of the motor (10) to cool multiple components of the power electronics assembly (109).

5. The cooling system (11, 11') according to any one of claims 3 to 4, wherein, The at least one machine air duct (110A) enables cooling of the stator (102) windings of the motor (10).

6. The cooling system (11') according to any one of the preceding claims, wherein, The hydraulic circuit (11H) includes at least one motor component pipe (110H) for cooling one of the motors (10).

7. A propeller-propulsion drive system (1, 1') having multiple motors, comprising: - Drive unit, including: Multiple motors (10), including rotors (100), stators (102) and housings (104). o Gearbox (12) includes: Each motor (10) has one gear, and each gear meshes with the rotor (100) of the corresponding motor (10). At least one propulsion wheel (124) meshes with each rotor (100) of the motor (10) via the gear. - The cooling system (11, 11') according to any one of the preceding claims.

8. The propulsion drive system (1, 1') according to claim 7, each motor (10) further includes a power electronics component (109).

9. The propulsion drive system (1') according to claim 8, comprising an electronic unit (19) including a power electronics unit (109) for each motor (10), and wherein, The hydraulic circuit is arranged to cool the electronic unit (19).

10. The propulsion drive system (1') according to any one of claims 7 or 8, comprising an electronic unit (19) including a power electronics unit (109) for each motor (10), and wherein, The air cooling circuit (11A') includes a portion for cooling the electronic unit (19).

11. The propulsion drive system (1) according to any one of claims 7 to 9, wherein, Each motor (10) includes a corresponding fan (110) that rotates integrally with the rotor (100) of the corresponding motor (10).

12. The propulsion drive system (1') according to any one of claims 7 to 9, wherein, The gearbox (12') includes at least two fans (110), and each fan (110) is engaged by a gear connected to a rotor (100) of the motor (10).

13. An electric propulsion aircraft (A) with vertical take-off and landing, comprising a transport body (2) and a propeller propulsion drive system (1, 1') equipped with at least one propeller having multiple motors according to any one of claims 7 to 12, and at least one propeller rotatably connected to a meshing propulsion wheel.

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