EP4409203A1

EP4409203A1 - Air delivery device

Info

Publication number: EP4409203A1
Application number: EP22786954.2A
Authority: EP
Inventors: Wei Zhang; Jiang PENG; Wei Su; Yumei Guo
Original assignee: Versuni Holding BV
Current assignee: Versuni Holding BV
Priority date: 2021-09-30
Filing date: 2022-09-27
Publication date: 2024-08-07
Anticipated expiration: 2042-09-27
Also published as: EP4409203B1; EP4160100A1; CN217876311U; PL4409203T3; WO2023052361A1; AU2022354085A1

Abstract

Related is to an air delivery device (100), including: a housing (10), defining an air inlet channel and an air outlet channel in fluid communication with the air inlet channel. The air outlet channel includes an air outflow channel (20) and an air leakage channel (30) branched from the air outflow channel (20). The housing further includes a first air outlet (12) in communication with the air outflow channel (20) and a second air outlet (14) in communication with the air leakage channel (30). The first air outlet (12) is configured to provide directional airflow suitable for being guided to a user, the second air outlet (14) is configured to provide non-directional airflow, and an opening degree of the air leakage channel (30) is selectively changeable, so as to adjust a functional mode of the air delivery device (100). Through the air delivery device, different functions of the air delivery device are significantly optimized.

Description

AIR DELIVERY DEVICE

FIELD

[0001] Embodiments of the present disclosure generally relate to air treatment devices, and more particularly, to an air delivery device for delivering treated air.

BACKGROUND

[0002] Various types of air treatment systems are widely used in occasions such as homes and offices, so as to provide different air treatment functions such as cooling airflow and purifying air. For example, in some scenarios, air purification is provided by driving ambient air to pass through a filter of a piece of equipment. In some other scenarios, air heating is provided and hot airflow is delivered. In yet another scenario, cooling is provided by providing ambient temperature airstream.

[0003] An air delivery system typically implements two or more of these functions. However, each function requires a different air flow rate and/or flow velocity to achieve an optimal effect. It is desirable to provide an air delivery system that can be operated in a more optimized manner in different operating modes.

SUMMARY

[0004] Embodiments of the present disclosure provide an air delivery device, so as to solve one or more of the above-mentioned problems, as well as other potential problems.

[0005] According to a first aspect of the present disclosure, provided is an air delivery device, including: a housing, defining an air inlet channel and an air outlet channel in fluid communication with the air inlet channel. The air outlet channel includes an air outflow channel and an air leakage channel branched from the air outflow channel. The housing further includes a first air outlet in communication with the air outflow channel and a second air outlet in communication with the air leakage channel, the first air outlet is configured to provide directional airflow suitable for being guided to a user, the second air outlet is configured to provide non-directional airflow, and an opening degree of the air leakage channel is selectively changeable, so as to adjust a functional mode of the air delivery device. When the opening degree of the air leakage channel is zero, the air delivery device is configured to be operated in a cooling mode, so that all airflow is guided to the user through the first air outlet, and when the opening degree of the air leakage channel is maximal, the air delivery device is configured to be operated a filtering mode, so that a majority of airflow is discharged to the environment by the second air outlet.

[0006] In the air delivery device according to the embodiments of the present disclosure, by means of controlling the opening degree of the air leakage channel, it is possible to conveniently realize the switching of different functions of the air delivery device and/or the balance between different functions.

[0007] In some embodiments, the housing at least partially includes a cylindrical shape, the air outflow channel is at least partially arranged in an axial direction of the cylindrical shape, and the air leakage channel is at least partially arranged in a circumferential direction of the cylindrical shape. Thereby, different openings of the air delivery device can be conveniently arranged, and it is possible to convenient adjust of the opening degree of the air leakage channel.

[0008] In some embodiments, the housing includes a fixed portion that is provided with a circumferential opening, and a movable door, which is configured to move in the circumferential direction so as to change the opening degree of the circumferential opening, the air leakage channel being formed by the circumferential opening. By means of the arrangement of the circumferential opening and the movable door, the opening degree of the air leakage channel can be conveniently adjusted.

[0009] In some embodiments, the movable door is configured to only perform rotational movement with respect to the fixed portion. Since the movable door only performs the rotational movement, the movement control on the circumferential opening of the air leakage channel can be greatly simplified.

[0010] In some embodiments, the housing includes a guide groove, and the movable door is configured to move along the guide groove. By means of the guide groove, the movable door can be conveniently positioned and guided.

[0011] In some embodiments, the air delivery device further includes a gear mechanism suitable for rotating the movable door, the gear mechanism includes a driving gear and a driven gear engaged with the driving gear, the driven gear is suitable for moving together with the movable door, and the driving gear is configured to be driven by a first motor. Thereby, the movement of the movable door can be realized by the gear mechanism.

[0012] In some embodiments, the air delivery device further includes a fan arranged in the air outlet channel, and the fan is arranged adjacent to the air leakage channel.

[0013] In some embodiments, the fan includes an oblique flow fan. Thereby, the air flow can be increased to enhance the performance of the air delivery device. In addition, the size of a fan assembly can be further reduced.

[0014] In some embodiments, air inlet sides of blades of the oblique flow fan are arranged in parallel with the axial direction of the fan.

[0015] In some embodiments, air outlet sides of blades of the oblique flow fan are arranged obliquely at an angle of 60°-75° with respect to the axial direction of the fan.

[0016] In some embodiments, blades of the oblique flow fan at least partially overlap, in the axial direction, with the circumferential opening on the air outlet sides. Thereby, the flow resistance of the air leakage channel can be reduced, and the air flow efficiency can be improved.

[0017] In some embodiments, the housing includes an outer housing and an inner housing, the air outflow channel is defined between the inner housing and the outer housing, and the inner housing is suitable for accommodating a second motor used for driving the fan.

[0018] In some embodiments, the fan is installed adjacent to a lower end of the inner housing and is coupled to an output shaft of the second motor by means of a D-shaped hole.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the embodiments of the present disclosure will become readily understood by reading the following detailed descriptions with reference to the drawings. In the drawings, several embodiments of the present disclosure are shown by way of example rather than limitation.

[0020] Fig 1 shows an overall schematic diagram of an air delivery device according to an embodiment of the present disclosure;

[0021] Fig 2 shows a partial schematic diagram of an air delivery device according to an embodiment of the present disclosure, an airflow direction being shown;

[0022] Fig 3 is a partial schematic diagram of an air delivery device according to an embodiment of the present disclosure, an axial portion of an air outflow channel being removed to show structural details of a circumferential portion of the air outflow channel, and a movable door being at a fully open position;

[0023] Fig 4 shows a partial schematic diagram of an air delivery device according to an embodiment of the present disclosure, the movable door being at an intermediate position;

[0024] Fig 5 shows a partial schematic diagram of an air delivery device according to an embodiment of the present disclosure, the movable door being at a closed position; [0025] Fig 6 shows a schematic cross-sectional view of a fan installed in an air delivery device according to an embodiment of the present disclosure, when being observed from an oblique upper side of the air delivery device;

[0026] Fig 7 shows a three-dimensional schematic diagram of an air inlet side of a fan according to an embodiment of the present disclosure; and

[0027] Fig 8 shows a three-dimensional schematic diagram of an air outlet side of a fan according to an embodiment of the present disclosure.

[0028] In the various drawings, the same or corresponding reference signs denote the same or corresponding portions.

DETAILED DESCRIPTION OF EMBODIMENTS

[0029] Preferred embodiments of the present disclosure will be described in more detail below with reference to the drawings. Although the preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided, so that the present disclosure will be thorough and complete, and the scope of the present disclosure may be fully delivered to those skilled in the art.

[0030] As used herein, the term "include" and variations thereof mean open-ended inclusion, that is, "including but not limited to". Unless specifically stated otherwise, the term "or" means "and/or". The term "based on" means "at least partially based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one additional embodiment." The terms "upper", "lower", "front", "rear" and other words that indicate placement or positional relationships are all based on orientation or positional relationships shown in the drawings, and are only for the convenience of describing the principles of the present disclosure, rather than indicating or implying that elements referred to must have particular orientations, or be constructed or operated in particular orientations, and thus cannot be construed as limitations of the present disclosure.

[0031] Fig 1 shows an overall schematic diagram of an air delivery device 100 according to an embodiment of the present disclosure. As shown in Fig. 1, the air delivery device 100 may include a housing 10 and a fan arranged in the housing 10. The housing 10 may define an air flow channel, and air flow power is provided by means of the rotation of the fan. The housing 10 may include a filter 50, and ambient air may enter the air flow channel of the housing 10 through the filter 50. An air purification function may be provided by providing the filter 50.

[0032] The air delivery device 100 may further include a first air outlet 12 and a second air outlet 14. The first air outlet 12 and the second air outlet 14 may be arranged at different heights, so as to provide airflow outputs at different heights. In some embodiments, the first air outlet 12 may be arranged at a higher position than the second air outlet 14. In some embodiments, the first air outlet 12 may be arranged on a front face of the air delivery device 100, and the height of the first air outlet 12 may be suitable for blowing air to the face of a user when the user is seated, so that air directly blown to the user may be provided by the first air outlet 12. The second air outlet 14 may be arranged at a lower position than the first air outlet 12. Optionally, the second air outlet 14 may be arranged on a back surface of the air delivery device 100. By means of the second air outlet 14, it is possible to provide airflow (i.e., non-directional air flow) that avoids disturbing the user as much as possible.

[0033] In the illustrated embodiment, the air delivery device 100 may include two symmetrically arranged first air outlets 12. The first air outlet 12 may have a shape of a long slit in a vertical direction and include a structure for providing predetermined directional airflow. This is particularly suitable for the case of high air flow velocity (i.e., the air flows out of the first air outlet 12 at a large flow velocity), so as to improve the perception of the user for the airflow. It is worth noting that this is merely exemplary. The air delivery device 100 may be provided with one or more first air outlets 12 according to the shape. In the illustrated embodiment, the air delivery device 100 may include one second air outlet 14. The second air outlet 14 extends at a greater width in a horizontal plane perpendicular to the vertical direction, which is particularly suitable for the case where a large flow rate is realized (i.e., the air flows out of the second air outlet 14 at a large flow rate). In this case, a large amount of air exchange may be quickly realized, but the perception of the user on the airflow is reduced. It is worth noting that the descriptions about the first air outlet 12 and the second air outlet 14 are only exemplary, and the air outlets may be implemented in any other manner as required.

[0034] It is worth noting that in the illustrated embodiment, the air delivery device 100 is shown in the shape of a vertical cylinder. It is worth noting that this is merely exemplary. The air delivery device 100 may be implemented in any other suitable shapes, so long as the air delivery device 100 can deliver the airflow with high efficiency. In some embodiments, the air delivery device may further include a heating device, which is suitable for heating the air in the air flow channel. This is particularly advantageous in winter scenarios, as an example.

[0035] As described above, in the case where the air delivery device 100 provides multiple functions, different functions require different air flow rates and/or flow velocities to achieve an optimal operation result. For example, for air purification, the user does not need to feel the airflow and but does need a large flow rate (to ensure the air treatment efficiency). For example, for cooling (in particular, ambient temperature air is used rather than cooling air), the user should feel the airflow to provide skin cooling. In this case, a more directional and higher air flow velocity is required. Therefore, there is a compromise in multifunctional equipment of the air delivery device 100. For example, high purification performance requires large air flow, and thus a large outlet is needed (to avoid flow restrictions reducing the flow). However, this large outlet size reduces the air velocity. On the other hand, in some application scenarios, such as in hot weather, the user needs a cooling function, so low-speed airflow is not enough; and the user expects high-speed airflow to achieve directional airflow supply, so the requirements for purification performance are lower. According to an embodiment of the present disclosure, an air delivery device 100 is provided, which realizes coordination among multiple functions with a simple structure without damaging other functions.

[0036] The structural details of the air delivery device 100 according to the embodiment of the present disclosure will be further described below with reference to Figs. 2-5.

[0037] In some embodiments, as shown in Fig. 2, the air delivery device 100 includes a housing 10, and the housing 10 may include an air inlet channel and an air outlet channel that is in fluid communication with the air inlet channel. In the illustrated embodiment, the air inlet channel may correspond to a lower side area of the housing, at which the airflow flows through the filter 50 to enter the housing. The air outlet channel may correspond to an upper side area of the housing and may correspond to the position of the air outlet of the fan, and the air outlet channel includes an air outflow channel 20 and an air leakage channel 30 branched from the air outlet channel 20. The air leakage channel 30 may be selectively located in an open state or a closed state, so as to adjust the air flow of flowing out through the air outflow channel 20 and/or air outlet speed.

[0038] In some embodiments, as shown in Fig. 2, the airflow flowing through the air leakage channel 30 is denoted by an arrow P2, and the air leakage channel 30 may correspond to the second air outlet 14 arranged in a horizontal direction, which is especially suitable for providing a large-flow channel. The air outflow channel 20 is denoted by an arrow Pl, and the airflow flowing through the air outflow channel 20 may flow out from the first air outlet 12, which is particularly suitable for providing directional and high-velocity airflow.

[0039] In the air delivery device 100 according to the embodiment of the present disclosure, by means of selectively controlling an opening degree of the air leakage channel 30, it is possible to conveniently adjust a functional state of the air delivery device 100.

[0040] As shown in Fig. 2, when the air leakage channel 30 is in a fully open state, the air delivery device 100 may execute a filtering function operation; part of the airflow in the air delivery device 100 may flow out to the environment by means of the air leakage channel 30, and part of the airflow in the air delivery device 100 flows out to the environment by means of the air outflow channel 20. Since the air leakage channel 30 is fully opened, the airflow may be discharged into the environment from the second air outlet 14 at large flow, so that efficient air treatment may be realized. On the other hand, since the air flow supplied to the air outflow channel 20 is reduced, the air flow from the air outflow channel 20 that the user may perceive is less. This corresponds to an air purification mode of the air delivery device 100.

[0041] As shown in Fig. 4, when the air leakage channel 30 is in an intermediate state between the fully open state and a fully closed state, the air delivery device 100 is capable of realizing a balance between a filtering function and a cooling function. Part of the airflow in the air delivery device 100 may leak from the air leakage channel 30, so the air exchange efficiency can be ensured to a certain extent; and moreover, part of the airflow leaks from an air flow branch 28, so the user can perceive the airflow from the air flow branch 28 in a gentle way. This corresponds to a balance mode between the purification mode and a cooling mode of the air delivery device 100.

[0042] As shown in Fig. 5, when the air leakage channel 30 is in the fully closed state, the air delivery device 100 can execute a cooling function operation. In this case, the airflow in the air delivery device 100 cannot leak from the air leakage channel 30, so all the airflow in the air delivery device 100 passes through the air outflow channel 20 and further is discharged to the environment by means of the first air outlet 12. Since the air flow provided for the air outflow channel 20 is the maximum, the user can perceive the strong airflow from the air flow branch 28. This corresponds to the cooling mode of the air delivery device 100. The cooling mode is not intended to mean only cooling, and the cooling mode here means a mode in which the air is discharged from the first air outlet 12 and the air flow rate is relatively high. Since the air discharged from the air outlet flows through a filtering device, the air discharged from the first air outlet 12 is filtered purified air.

[0043] In some embodiments, as shown in Fig. 2, the housing 10 at least partially includes a cylindrical shape, the air outflow channel 20 is at least partially arranged in an axial direction of the cylindrical shape, and the air leakage channel 30 is at least partially arranged in a circumferential direction of the cylindrical shape.

[0044] In some embodiments, as shown in Fig. 2 and Fig. 3, the housing 10 includes a fixed portion 22 provided with a circumferential opening 29, and a movable door 25. The movable door 25 moves in the circumferential direction. Therefore, the opening degree of the circumferential opening 29 may be continuously adjusted by means of the movable door 25. The circumferential opening 29 may form the air leakage channel 30.

[0045] In some embodiments, the movable door 25 only performs rotational movement with respect to the fixed portion 22. In this case, the control on the opening degree of the air leakage channel 30 can be greatly simplified, and a corresponding driving mechanism can be simplified. In some embodiments, the housing 10 may include a circumferential guide groove. The movable door 25 is configured to move along the circumferential guide groove.

[0046] In some embodiments, the movable door 25 only performs linear movement with respect to the fixed portion 22. In this case, the circumferential opening may have a non-circular shape, that is, a rectilinear shape.

[0047] In some embodiments, the movable door 25 may be moved manually. In other embodiments, the movable door 25 may be automatically controlled to move. For example, the user may selectively set the functional mode of the air delivery device 100. The air delivery device 100 may set the opening degree of the air leakage channel 30 on the basis of the functional mode.

[0048] In some embodiments, the driving mechanism may include a gear mechanism suitable for driving the movable door 25 to rotate. The gear mechanism includes a driving gear 26 and a driven gear 24 engaged with the driving gear 26, the driven gear is suitable for moving together with the movable door 25, and the driving gear is driven by a first motor 28. It is worth noting that the illustrated gear mechanism is only exemplary, and other driving mechanisms excluding the gear mechanism may be used. In addition, the gear structure may be implemented in any other suitable form. For example, in some other embodiments, in the case where the movable door only performs the linear movement, the gear mechanism may include a pinion and rack structure.

[0049] In some embodiments, the first motor 28 may include a stepping motor. Precise control on a rotation angle of the movable door 25 may be implemented by the stepping motor. It is worth noting that this is merely exemplary; and any other suitable type of motor may be used as the motor.

[0050] As shown in Figs. 2-4, the air delivery device 100 may further include a fan 40 arranged in the air outlet channel. By means of the fan, a negative pressure may be created in the housing 10 to suck the ambient air into the housing 10 for air treatment. In some embodiments, the air leakage channel 30 is arranged in relation to the filtering function (that is, providing air outflow at a large flow rate), and the fan 40 is arranged adjacent to the air leakage channel 30. In this case, the air outlet efficiency of the air leakage channel 30 can be improved on the premise of ensuring the structural compactness of the air delivery device 100.

[0051] In some embodiments, the fan 40 may include an oblique flow fan. By means of the oblique flow fan, the air flow of the air leakage channel 30 can be further increased. Considering the versatility of the air delivery device 100 and the function of the air leakage channel 30, even if the oblique flow fan is used, the air flow of the air flow branch 28 will not be affected; and on the contrary, the versatility of the air delivery device 100 can be better balanced. In addition, the use of the oblique flow fan can also make it possible to miniaturize the fan on the premise of providing the same air volume.

[0052] The structure of the fan 40 according to the embodiment of the present disclosure will be further described below with reference to Figs. 6-8.

[0053] In some embodiments, as shown in Fig. 6, the housing 10 includes an outer housing 10 and an inner housing 10. The air outflow channel 20 is defined between the inner housing 10 and the outer housing 10, and the inner housing 10 is suitable for accommodating a second motor 62 that is used for driving the fan 40. This solution of the inner housing and the outer housing can ensure the space efficiency of the air delivery device 100. In some embodiments, the fan 40 is installed adjacent to a lower end of the inner housing 10 and is coupled to an output shaft of the second motor by means of a D-shaped hole. Thereby, the installation strength of the fan can be improved.

[0054] In some embodiments, as shown in Fig. 7, air inlet sides 42a of blades 42 of the oblique flow fan are arranged in parallel with the axial direction of the fan 40. In this case, it can be ensured that the air flows parallel to the blades 42 on the air inlet sides 42a, thereby ensuring the efficiency of the air entering the fan.

[0055] In some embodiments, as shown in Fig. 8, air outlet sides 42b of the blades 42 of the oblique flow fan are arranged obliquely at an angle of 60°-75° with respect to the axial direction of the fan 40. In this case, the efficiency of the air flowing out from the fan can be ensured.

[0056] In some embodiments, as shown in Figs. 2-4, the blades 42 of the oblique flow fan at least partially overlap, in the axial direction, with the circumferential opening 29 on the air outlet sides 42b. In this case, the air outlet of the oblique flow fan is directly communicated to the circumferential opening 29, which can minimize the loss of airflow efficiency caused by airflow resistance.

[0057] In addition, although various operations are described in a particular order, it should be understood that such operations are required to be executed in the illustrated particular order or in a sequential order, or all illustrated operations should be executed to achieve desired results. Under certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although the above discussions contain several specific implementation details, these discussions should not be construed as limitations on the scope of the present disclosure. Some features that are described in the context of separate embodiments may also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation may also be implemented in multiple implementations separately or in any suitable sub-combinations.

[0058] Although the present subject has been described in language that is specific to structural features and/or method logical actions, it should be understood that the subject defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely example forms for implementing the claims.

[0059] Various embodiments of the present disclosure have been described above, and the foregoing descriptions are exemplary, not exhaustive, and are not limited to various disclosed embodiments. Numerous modifications and variations are apparent to those of ordinary skill in the art without departing from the scope and spirit of the various described embodiments. The terms used herein are chosen to best explain the principles of the various embodiments, practical applications or technical improvement in the market, or to enable others of ordinary skill in the art to understand the various embodiments disclosed herein.

Claims

I/We Claim:

1. An air delivery device (100), comprising: a housing (10) defining an air inlet channel and an air outlet channel in fluid communication with the air inlet channel, the air outlet channel comprising an air outflow channel (20) and an air leakage channel (30) branched from the air outflow channel (20), and the housing further comprising a first air outlet (12) in communication with the air outflow channel (20) and a second air outlet (14) in communication with the air leakage channel (30), the first air outlet (12) being configured to provide directional airflow suitable for being guided to a user, and the second air outlet (14) being configured to provide non-directional airflow, and an opening degree of the air leakage channel (30) being selectively changeable so as to adjust a functional mode of the air delivery device (100): wherein when the opening degree of the air leakage channel (30) is zero, the air delivery device (100) is configured to be operated in a cooling mode, so that all airflow is guided to the user through the first air outlet (12), and when the opening degree of the air leakage channel (30) is maximal, the air delivery device (100) is configured to be operated in a filtering mode, so that a majority of airflow is discharged to the environment by the second air outlet (14).

2. The air delivery device (100) according to claim 1, wherein the housing (10) at least partially comprises a cylindrical shape, the air outflow channel (20) is at least partially arranged in an axial direction of the cylindrical shape, and the air leakage channel (30) is at least partially arranged in a circumferential direction of the cylindrical shape.

3. The air delivery device (100) according to claim 2, wherein the housing (10) comprises a fixed portion (22) having a circumferential opening (29) and a movable door (25) which is configured to move in the circumferential direction so as to change the opening degree of the circumferential opening (29), the air leakage channel (30) being formed by the circumferential opening (29).

4. The air delivery device (100) according to claim 3, wherein the movable door (25) is configured to only perform rotational movement with respect to the fixed portion (22).

5. The air delivery device (100) according to claim 4, wherein the housing (10) comprises a guide groove, and the movable door (25) is configured to move along the guide groove.

6. The air delivery device (100) according to claim 4 or 5, further comprising a gear mechanism suitable for rotating the movable door (25), the gear mechanism comprising a driving gear (26) and a driven gear (24) engaged with the driving gear (26), the driven gear being suitable for moving together with the movable door (25), and the driving gear being configured to be driven by a first motor (28).

7. The air delivery device (100) according to any one of claims 3-5, further comprising a fan (40) arranged in the air outlet channel, the fan (40) being arranged adjacent to the air leakage channel (30).

8. The air delivery device (100) according to claim 7, wherein the fan (40) comprises an oblique flow fan.

9. The air delivery device (100) according to claim 8, wherein air inlet sides (42a) of blades (42a) of the oblique flow fan are arranged in parallel with an axial direction of the fan (40).

10. The air delivery device (100) according to claim 8, wherein air outlet sides (42b) of blades (42) of the oblique flow fan are arranged obliquely at an angle of 60°-75° with respect to an axial direction of the fan (40).

11. The air delivery device (100) according to claim 7, wherein blades (42) of the oblique flow fan at least partially overlap, in an axial direction, with the circumferential opening (29) on the air outlet sides (42b).

12. The air delivery device (100) according to any one of claims 2-5 and 8-11, wherein the housing (10) comprises an outer housing (10) and an inner housing (10), the air outflow channel (20) is defined between the inner housing (10) and the outer housing (10), and the inner housing (10) is suitable for accommodating a second motor (62) used for driving the fan (40).

13. The air delivery device (100) according to claim 12, wherein the fan (40) is installed adjacent to a lower end of the inner housing (10) and is coupled to an output shaft of the second motor by means of a D-shaped hole.