CN214756008U

CN214756008U - Counter-rotating fan driving assembly and fan assembly

Info

Publication number: CN214756008U
Application number: CN202022713499.4U
Authority: CN
Inventors: A.玛丽-马格德莱因; H.C.蒂拉卡瓦德哈纳; R.J.弗赖尔
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2019-12-20
Filing date: 2020-11-20
Publication date: 2021-11-16
Anticipated expiration: 2030-11-20
Also published as: GB2590631B; GB201919013D0; CN113014051A; WO2021123708A1; GB2590631A

Abstract

There is provided a counter-rotating fan drive assembly and a fan assembly comprising: a first impeller; a first motor including an inner rotor, an outer stator, and a drive shaft connecting the inner rotor and a first impeller, the first motor arranged to rotate the first impeller in a first direction; a second impeller; and a second motor including an inner stator and an outer rotor connected to the second impeller, the second motor being arranged to rotate the second impeller in a second direction opposite to the first direction, wherein the first and second motors are coaxially arranged, and wherein the second motor is arranged between the first impeller and the first motor, and the inner stator of the second motor includes a hole through which a driving shaft of the first motor passes.

Description

Counter-rotating fan driving assembly and fan assembly

Technical Field

The present invention relates to a disrotatory fan drive assembly and to a fan assembly including a disrotatory fan drive assembly.

Background

Conventional domestic fans typically include an impeller comprising a set of blades mounted for rotation about an axis, and a fan drive assembly for rotating the impeller to generate an airflow. The movement and circulation of the air flow generates a breeze, and as a result, the user dissipates heat by convection and evaporation, thereby obtaining a cooling effect. The rotation of the impeller blades imparts a tangential or rotational component in the direction of air flowing through the impeller. This not only reduces the mass flow through the fan and increases energy losses, but also applies a torque or steering force on the fan. It is known to compensate for these drawbacks by using two coaxial impellers (commonly known as contra-rotating impellers) rotating in opposite directions. In this arrangement, rotation of the downstream impeller eliminates a rotational component applied to air flowing through the upstream impeller, thereby maximizing the mass flow rate through the fan and minimizing energy losses. The torque acting on the fan can also be effectively counteracted due to the counter-rotating impellers. However, counter-rotating impellers are not widely used in domestic fans, partly due to their expense, but also due to the fact that they occupy more space than fans comprising a single impeller.

It is an object of the present invention to substantially alleviate some of the disadvantages associated with counter-rotating impellers.

SUMMERY OF THE UTILITY MODEL

According to an aspect of the utility model, a disrotatory fan drive assembly is provided, include: a first impeller; a first motor including an inner rotor, an outer stator, and a drive shaft connecting the inner rotor and a first impeller, the first motor arranged to rotate the first impeller in a first direction; a second impeller; and a second motor including an inner stator and an outer rotor connected to the second impeller, the second motor being arranged to rotate the second impeller in a second direction opposite to the first direction, wherein the first and second motors are coaxially arranged, and wherein the second motor is arranged between the first impeller and the first motor, and the inner stator of the second motor includes a hole through which a driving shaft of the first motor passes.

Preferably, the first motor and the second motor are axially spaced apart. Preferably, the first impeller is arranged coaxially with both the first motor and the second motor. Preferably, the second impeller is arranged coaxially with both the first motor and the second motor.

Preferably, the second motor is shaftless. Preferably, the second impeller is directly connected or mounted to the outer rotor of the second motor. Preferably, the blades of the second impeller extend outwardly from an outer surface of the outer rotor of the second motor.

According to another aspect of the present invention, there is provided a fan assembly comprising a counter-rotating fan drive assembly according to the preceding aspect.

According to the utility model discloses an on the other hand provides a disrotatory drive assembly, include: a first set of blades; an inner rotary motor for rotating the first set of blades in a first direction, the inner rotary motor comprising an inner rotor, an outer stator, and a drive shaft connecting the inner rotor and the first set of blades; a second set of blades; and an out-of-axis turning motor for rotating a second set of blades in a second direction opposite to the first direction, the out-of-axis turning motor including an inner stator and an outer rotor, the second set of blades being connected to the outer rotor; wherein the inner turn motor and the non-axial outer turn motor are coaxially arranged, and wherein the non-axial outer turn motor is arranged between the first set of blades and the inner turn motor, and an inner stator of the non-axial outer turn motor comprises an aperture through which a drive shaft of the inner turn motor passes.

According to the utility model discloses an on the other hand provides a disrotatory fan drive assembly, include: a first impeller; a first motor including an inner rotor, an outer stator, and a drive shaft connecting the inner rotor and a first impeller, the first motor arranged to rotate the first impeller in a first direction; a second impeller; and a second motor comprising an inner stator and an outer rotor connected to the second impeller, the second motor being arranged to rotate the second impeller in a second direction opposite to the first direction, wherein the first and second motors are arranged coaxially, and wherein the first motor is arranged concentrically within the second motor such that the second motor surrounds the periphery of the first motor.

Preferably, the inner stator of the second motor comprises an aperture for receiving the first motor such that the inner stator of the second motor is circumferentially arranged around the outer stator of the first motor. Preferably, the first impeller is arranged coaxially with both the first motor and the second motor. Preferably, the second impeller is arranged coaxially with both the first motor and the second motor.

According to the utility model discloses an on the other hand provides a disrotatory drive assembly, include: a first set of blades; an inner rotary motor for rotating the first set of blades in a first direction, the inner rotary motor comprising an inner rotor, an outer stator, and a drive shaft connecting the inner rotor and the first set of blades; a second set of blades; and an out-of-axis turning motor for rotating a second set of blades in a second direction opposite to the first direction, the out-of-axis turning motor including an inner stator and an outer rotor, the second set of blades being connected to the outer rotor; wherein the inner turning motor and the shaftless outer turning motor are coaxially arranged, and wherein the inner turning motor is concentrically arranged within the shaftless outer turning motor such that the outer turning motor surrounds the periphery of the inner turning motor.

Preferably, the inner stator of the shaftless external rotation motor comprises an aperture for receiving the internal rotation motor such that the inner stator of the shaftless external rotation motor is arranged circumferentially around the outer stator of the internal rotation motor.

Drawings

For a better understanding of the above and other aspects of the invention, reference is made to the following description, which is to be used in conjunction with the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a fan assembly including a counter-rotating fan drive assembly according to an embodiment of the present invention; and the combination of (a) and (b),

fig. 2 is a cross-sectional view of a fan assembly including a counter-rotating fan drive assembly according to another embodiment of the present invention.

In the drawings, like reference numerals designate corresponding parts throughout the several views, where appropriate.

Detailed Description

There will now be described specific embodiments of the present invention, in which many features will be discussed in detail in order to provide a thorough understanding of the inventive concepts as defined in the appended claims. It will be apparent, however, to the reader that the present invention may be practiced without some of these specific details, and in some instances, well-known methods, techniques, and structures have not been described in detail so as not to obscure the inventive concepts.

The present inventive concept is intended to cover a contra-rotating fan drive assembly comprising a coaxial motor arrangement, which enables the space occupied by the assembly to be reduced compared to known contra-rotating fan drive assemblies, as defined in the appended claims.

Fig. 1 shows a fan assembly 2 including a counter-rotating fan drive assembly 4 according to an embodiment of the present invention. The fan assembly 2 includes a main housing 6 forming a duct 8 defining an annular air flow path 10 extending through the fan assembly 2. The conduit 8 comprises: a first end defining an annular air inlet 12 through which drive assembly 4 is configured to draw air into conduit 8 through annular air inlet 122; and a second end opposite the first end and defining an annular air outlet 16, at which air that has been processed by the drive assembly 4 is pumped out of the conduit 8. The fan drive assembly 4 then comprises a first impeller 14 arranged adjacent the air inlet 12 and a second impeller 18 arranged adjacent the air outlet 16. The first impeller 14 includes a cover 19 for directing incoming air towards the annular air inlet 12. The conduit 8 is aligned with the drive assembly 4 such that its longitudinal axis is collinear with the axis of rotation 20 of the counter-rotating fan drive assembly 4.

The first and

second impellers

14, 18 are mixed flow impellers, each including a generally conical hub 22, a plurality of curved impeller blades 24 connected to the conical hub 22, and an annular shroud 26 connected to the impeller blades 24 so as to surround the conical hub 22 and the impeller blades 24. The impeller blades 24 are preferably integral with the tapered hub 22, and the tapered hub 22 is preferably formed of a plastic material.

The annular air flow path 10 is defined by an inner side of the outer wall 30 of the main housing 6 and a radially outer side 32 of the conical hub 22 and a radially outer side 34 of an inner wall 36 of the main housing located adjacent the second impeller 18 and extending circumferentially around a first motor 38.

The counter-rotating fan drive assembly 4 includes a first motor 38 and a second motor 40 coaxially mounted on a drive shaft 42, and a power cable (not shown) for supplying power to the first motor 38 and the second motor 40. The first motor 38 and the second motor 40 may be brushless DC electric motors with independently variable speeds, which are controlled by a control circuit (not shown). Such electric motors and control circuits will be familiar to the person skilled in the art and will therefore not be discussed in further detail. The fact that the speeds of the first motor 38 and the second motor 40 can be independently controlled means that the quietest operating point can be established, as opposed to a single motor gear pair rotating fan drive assembly, which provides a fixed power distribution between the impellers. The drive shaft 42 is configured to rotate about the rotational axis 20 and is rotatably supported within the main housing 6 by first, second and

third bearings

44, 46, 48.

The first motor 38 is an internal rotation motor, which includes: an outer stator assembly 50 surrounding an inner rotor assembly 52, the inner rotor assembly 52 configured to rotate relative to the outer stator assembly 50; and a drive shaft 42 secured to the inner rotor assembly 52 near one of its ends. The outer stator assembly 50 includes a drum or bell housing 54 and a radial mounting plate 56 secured to the open end of the bell housing. The bell housing 54 is fixed to the inside of the rear wall 55 of the main housing 6 by a circumferential coupling 57, the circumferential coupling 57 being concentrically aligned with the axis of rotation 20. The outer side of the rear wall 55 carries a stator cover 59, the stator cover 59 being shaped to continue the outer side 34 of the inner wall 36 of the main housing 6 to ensure a smooth outflow of air from the annular air outlet 16. The first bearing 44 is located between the drive shaft 42 and the radial mounting plate 56 to rotatably isolate the outer stator assembly 50 from the drive shaft 42. The drive shaft 42 extends outwardly from the first motor 38 and is connected with the first impeller 14 to transfer rotation of the inner rotor assembly 52 to the first impeller 14, the first impeller 14 being configured to rotate in a first direction about the rotational axis 20, for example, in a direction in which the impeller blades 24 of the first impeller 14 are curved.

The second motor 40 is an outer rotor motor that includes an inner stator assembly 58 held within an outer rotor assembly 60, the outer rotor assembly 60 being configured to rotate relative to the inner stator assembly 58. The second motor 40 is "shaftless," such that unlike the first motor 38, the rotor assembly 60 of the second motor 40 is not configured to drive a drive shaft in order to transfer rotation to the impeller. The inner stator assembly 58 includes an elongated sleeve 62, the elongated sleeve 62 defining a concentric bore 64 through which the drive shaft 42 of the first motor 38 passes such that the second motor 40 is disposed between the first impeller 14 and the first motor 38. The end of the elongated sleeve 62 proximate the bell housing 54 of the first motor 38 includes a flange 66 secured to the bell housing 54 of the first motor 38 that connects the outer stator assembly 50 of the first motor 38 and the inner stator assembly 58 of the second motor 40. This arrangement avoids the need for separate structures to support the outer stator assembly 50 of the first motor 38 and the inner stator assembly 58 of the second motor 40, which would increase the space occupied by the counter-rotating fan drive assembly 4. The other end of the elongated sleeve 62 includes a narrowed ring portion 68. The second and

third bearings

46, 48 are disposed between the drive shaft 42 and the inner radial side of the narrowed ring portion 68 and the flange 66 to rotatably isolate the second motor 40 from the drive shaft 42. The outer rotor assembly 60 includes a drum or bell housing 70 that is rotatably supported on an outer radial side of the narrowed ring portion 68 of the inner stator assembly 58 by a fourth bearing 72. The tapered hub 22 of the second impeller 18 is directly connected or mounted to the outer rotor assembly 60 via the bell housing 70 such that rotation of the outer rotor assembly 60 drives the second impeller 18 to rotate about the axis of rotation 20 in a second direction, opposite the first direction in which the first impeller 14 is configured to rotate.

Fig. 2 shows a fan assembly 2 comprising a counter-rotating fan drive assembly 4 according to another embodiment of the present invention. The fan assembly 2 of this embodiment is similar to that shown in figure 1 in that it comprises a main housing 6 which forms a duct 8 which defines an annular air flow path 10 extending through the fan assembly 2. The conduit 8 comprises: a first end defining an annular air inlet 12 through which drive assembly 4 is configured to draw air into conduit 8 through annular air inlet 122; and a second end opposite the first end and defining an annular air outlet 16, at which air that has been processed by the drive assembly 4 is pumped out of the conduit 8. The fan drive assembly 4 then comprises a first impeller 14 arranged adjacent the air inlet 12 and a second impeller 18 arranged adjacent the air outlet 16. The first impeller 14 comprises a cover 19 for directing incoming air towards the annular air inlet 12. The conduit 8 may be aligned with the drive assembly 4 such that its longitudinal axis is collinear with the axis of rotation 20 of the counter-rotating fan drive assembly 4.

The first and

second impellers

The annular air flow path 10 is defined by the inner side of the outer wall 30 of the main housing 6 and the radially outer side 32 of the conical hub 22 and the radially outer side 34 of the inner wall 36 of the main housing located adjacent the second impeller 18.

The counter-rotating fan driving assembly 4 includes: a first motor 38 and a second motor 40, which in this embodiment are mounted coaxially about a drive shaft 42 defining an axis of rotation; and a power cable (not shown) for supplying electric power to the first motor 38 and the second motor 40. The drive shaft 42 is supported within the main housing 6 by first, second and

third bearings

44, 46, 48. As with the previous embodiment, the first motor 38 and the second motor 40 may be brushless DC electric motors having independently variable speeds, which are controlled by a control circuit (not shown).

The first motor 38 is an internal rotation motor, which includes: an outer stator assembly 50 surrounding an inner rotor assembly 52, the inner rotor assembly 52 configured to rotate relative to the outer stator assembly 50; and a drive shaft 42 secured to the inner rotor assembly 52. The outer stator assembly 50 includes a drum or bell housing 54 that is rotatably isolated from the drive shaft 42 by the first bearing 44 and the second bearing 46, thereby rotatably isolating the outer stator assembly 50 from the drive shaft 42. The bell housing 54 is fixed to the inside of the rear wall 55 of the main housing 6 by a circumferential coupling 57, the circumferential coupling 57 being concentrically aligned with the axis of rotation 20. The outer side of the rear wall 55 carries a stator cover 59, the stator cover 59 being shaped to continue the outer side 34 of the inner wall 36 of the main housing 6 to ensure a smooth outflow of air from the annular air outlet 16. The drive shaft 42 extends outwardly from the first motor 38 and is connected with the first impeller 14 to transfer rotation of the inner rotor assembly 52 to the first impeller 14, the first impeller 14 being configured to rotate in a first direction about the rotational axis 20, for example, in a direction in which the impeller blades 24 of the first impeller 14 are curved.

The second motor 40 is an outer rotor motor that includes an inner stator assembly 58 held within an outer rotor assembly 60, the outer rotor assembly 60 being configured to rotate relative to the inner stator assembly 58. The second motor 40 is "shaftless," such that unlike the first motor 38, the rotor assembly 60 of the second motor 40 is not configured to drive a drive shaft in order to transfer rotation to the impeller. In this embodiment, the inner stator assembly 58 defines a concentric bore in which the first motor 38 is held such that the first motor 38 is concentrically disposed within the second motor 40. That is, the second motor 40 surrounds the circumference/periphery of the first motor 38. Specifically, the inner stator assembly 58 of the second motor 40 is circumferentially arranged about the outer stator assembly 50 of the first motor 38. In such an arrangement, the inner stator assembly 58 of the second motor 40 may be directly or indirectly connected to the outer radial surface of the bell housing 54 of the first motor 38. The outer rotor assembly 60 includes a drum or bell housing 70 supported on the drive shaft 42 by the third bearing 48 to rotatably isolate the second motor 40 from the drive shaft 42. The tapered hub 22 of the second impeller 18 is directly connected or mounted to the outer rotor assembly 60 via the bell housing 70 such that rotation of the outer rotor assembly 60 drives the second impeller 18 to rotate about the axis of rotation 20 in a second direction, opposite the first direction in which the first impeller 14 rotates. By arranging the first motor 38 concentrically within the second motor 40, it is meant that the second motor 40 need not be supported directly on the drive shaft 42. This in turn means that the length of the drive shaft 42 can be shortened compared to the embodiment of figure 1, which means that the counter-rotating fan drive assembly 4 occupies relatively less space within the fan assembly 2.

It will be appreciated by persons skilled in the art that the present invention has been described by way of example only, and that various alternatives or modifications may be employed without departing from the scope of the invention as defined by the appended claims. For example, in both embodiments described above, the tapered hub 22 of the second impeller 18 is connected to the outer rotor assembly 60 of the second motor 40 by the bell housing 70. However, embodiments are contemplated in which the tapered hub 22 is not required and the plurality of impeller blades 24 of the second impeller 18 extend directly outward from the outer radial surface of the outer rotor assembly 60. In such embodiments, the outer radial surface may be defined by the bell housing 70 of the outer rotor assembly 60. Further, in the above-described embodiment, the counter-rotating first and

second impellers

14, 18 function to pump air through the annular air flow path 10, but those skilled in the art will appreciate that such function of pumping air through the annular air flow path 10 may also be performed by counter-rotating propellers each having a plurality of blades.

In all embodiments, the first motor 38, which is an internal rotation motor, is arranged to drive the rotation of the first impeller 14, which first impeller 14 is the front impeller of the counter-rotating fan drive assembly 4. This arrangement is advantageous because from an aerodynamic point of view the front impeller in a counter-rotating fan arrangement requires more power and rotational speed than the rear impeller, and the inner rotating motor can produce a higher rotational speed than the outer rotating motor and is therefore more efficient.

Furthermore, the embodiments described above all relate to a counter-rotating drive assembly for driving a fan and therefore comprise a first counter-rotating impeller and a second counter-rotating impeller, wherein the impellers are rotating parts of a machine designed to move a fluid. However, those skilled in the art will appreciate that the above-described contra-rotating drive assembly may equally be used to drive a contra-rotating propeller to produce thrust.

The fan drive assembly according to the invention has been described with reference to specific embodiments thereof in order to illustrate the operating principle. Thus, the foregoing description is by way of illustration and directional references (including: upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, side, upper, lower, front, middle, rear, vertical, horizontal, height, depth width, etc.) and any other terms used herein that have an implied orientation refer only to the orientation of the feature illustrated in the drawings. They are not to be interpreted as required or limited, except as may be expressly recited in the appended claims, particularly with respect to a position, orientation, or use of the invention. Connection references (e.g., attached, coupled, connected, engaged, fixed, etc.) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. Thus, unless specifically set forth in the following claims, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other.

Claims

1. A counter-rotating fan drive assembly, comprising:

a first impeller;

a first motor comprising an inner rotor assembly, an outer stator assembly, and a drive shaft connecting the inner rotor assembly and a first impeller, the first motor arranged to rotate the first impeller in a first direction;

a second impeller; and

a second motor including an inner stator assembly and an outer rotor assembly connected to the second impeller, the second motor arranged to rotate the second impeller in a second direction opposite the first direction,

wherein the first motor and the second motor are coaxially arranged, and wherein the second motor is arranged between the first impeller and the first motor, and the inner stator assembly of the second motor comprises an aperture through which the drive shaft of the first motor passes.

2. The counter-rotating fan drive assembly according to claim 1, wherein the second motor is shaftless.

3. The counter-rotating fan drive assembly according to claim 1, wherein the second impeller is directly connected to an outer rotor assembly of the second motor.

4. The counter-rotating fan drive assembly according to any one of claims 1 to 3, wherein the blades of the second impeller extend outward from an outer surface of the outer rotor assembly of the second motor.

5. A fan assembly comprising a counter-rotating fan drive assembly according to any one of claims 1 to 4.

6. A counter-rotating fan drive assembly, comprising:

a first set of blades;

an inner rotary motor for rotating the first set of blades in a first direction, the inner rotary motor comprising an inner rotor assembly (52), an outer stator assembly, and a drive shaft connecting the inner rotor assembly and the first set of blades;

a second set of blades; and

an off-axis motor for rotating a second set of blades in a second direction opposite the first direction, the off-axis motor including an inner stator assembly and an outer rotor assembly, the second set of blades being coupled to the outer rotor assembly;

wherein the inner turn motor and the non-axial outer turn motor are coaxially arranged, and wherein the non-axial outer turn motor is arranged between the first set of blades and the inner turn motor, and an inner stator assembly of the non-axial outer turn motor includes an aperture through which a shaft of the inner turn motor passes.