CN113014052A

CN113014052A - Fan driving assembly

Info

Publication number: CN113014052A
Application number: CN202011311984.7A
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: 2021-06-22
Also published as: CN214756007U; GB201919012D0; GB2590630B; GB2590630A; WO2021123707A1

Abstract

According to one aspect of the present invention, there is provided a counter-rotating drive assembly comprising a first impeller, a second impeller and a counter-rotating motor. The counter-rotating motor comprises a drive shaft, an inner rotor and an outer rotor, wherein the inner rotor is fixedly connected to the drive shaft and the outer rotor is arranged to rotate relative to the drive shaft. The first impeller is fixedly connected to the drive shaft for rotation therewith, and the second impeller is fixedly connected to the outer rotor for rotation therewith. The counter-rotating electric motor includes a battery fixed relative to a first one of the inner and outer rotors for rotation therewith, the battery being arranged to provide current to the first one of the inner and outer rotors to rotate the inner and outer rotors in opposite directions.

Description

Fan driving assembly

Technical Field

The present invention relates to a counter-rotating fan drive assembly, and to a fan assembly including a counter-rotating fan drive assembly.

Background

Conventional domestic and industrial fans typically include an impeller comprising a set of blades mounted for rotation about an axis, and a 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, a user or device may dissipate heat by convection and evaporation, thereby obtaining a cooling effect. The rotation of the 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 remedy these drawbacks by using two coaxial impellers (commonly known as contra-rotating fans) 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 or industrial fans, partly due to their expense, but also due to the fact that they occupy more space than fans comprising a single impeller.

Existing counter-rotating fans use two separate motors to drive the impellers, or a single motor coupled to a gear train arranged to drive the two impellers in opposite directions. Such an arrangement is expensive and cumbersome to package. In addition, the use of gears can cause noise and increase the inefficiency of the system.

It has been proposed to drive counter-rotating impellers using a counter-rotating motor powered by non-contact power transmission. However, such power supplies are expensive and have limited capacity.

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

Disclosure of Invention

The counter-rotating electric motor may include a motor controller fixed relative to the battery for rotation therewith, the motor controller being arranged to receive current from the battery and control the supply of current to a first one of the inner and outer rotors.

The counter-rotating motor may include a motor mounting assembly, and then the drive shaft may be rotatably mounted to the motor mounting assembly. A first end of the drive shaft may be rotatably mounted to the motor mounting assembly while the first impeller is fixedly connected to an opposite second end of the drive shaft. The inner rotor may be disposed between the first end and the second end of the drive shaft.

The outer rotor may be concentrically arranged around the inner rotor. The outer rotor includes a rotor housing rotatably mounted to the drive shaft and the second impeller is fixedly connected to the rotor housing. The battery may be fixedly connected to the rotor housing. The motor controller may be fixedly connected to the rotor housing.

The inner rotor may include permanent magnets and the outer rotor may include electromagnets. Alternatively, the inner rotor may comprise electromagnets and the outer rotor may comprise permanent magnets.

According to another aspect of the present invention, a counter-rotating drive assembly is provided that includes a first set of blades, a second set of blades, and a counter-rotating motor. The counter-rotating motor comprises a drive shaft, an inner rotor and an outer rotor, wherein the inner rotor is fixedly connected to the drive shaft and the outer rotor is arranged to rotate relative to the drive shaft. The first set of blades is fixedly connected to the drive shaft for rotation therewith, and the second set of blades is fixedly connected to the outer rotor for rotation therewith. The counter-rotating electric motor includes a battery fixed relative to a first one of the inner and outer rotors for rotation therewith, the battery being arranged to provide current to the first one of the inner and outer rotors to rotate the inner and outer rotors in opposite directions.

A counter-rotating fan drive assembly is provided that includes a first impeller, a second impeller, and a counter-rotating electric motor. The counter-rotating motor comprises a drive shaft, an inner rotor and an outer rotor, wherein the inner rotor is fixedly connected to the drive shaft and the outer rotor is arranged to rotate relative to the drive shaft. The first impeller is fixedly connected to the drive shaft for rotation therewith, and the second impeller is fixedly connected to the outer rotor for rotation therewith. The counter-rotating electric motor includes a motor controller fixed relative to a first one of the inner and outer rotors for rotation therewith, the motor controller being arranged to provide an electric current to the first one of the inner and outer rotors to rotate the inner and outer rotors in opposite directions.

The counter-rotating electric motor includes a sliding electrical contact assembly, the motor controller arranged to receive electric current via the sliding electrical contact assembly and control the provision of electric current to the first one of the inner and outer rotors. The sliding electrical contact assembly includes: a fixed portion fixedly connected to the motor mounting assembly; and a rotatable portion fixedly connected to a first one of the inner and outer rotors for rotation therewith, the fixed portion being in electrical contact with the rotatable portion.

The outer rotor may be concentrically arranged around the inner rotor. The outer rotor includes a rotor housing rotatably mounted to the drive shaft and the second impeller is fixedly connected to the rotor housing. The motor controller may be fixedly connected to the rotor housing.

A counter-rotating drive assembly is also provided that includes a first set of blades, a second set of blades, and a counter-rotating motor. The counter-rotating motor comprises a drive shaft, an inner rotor and an outer rotor, wherein the inner rotor is fixedly connected to the drive shaft and the outer rotor is arranged to rotate relative to the drive shaft. The first set of blades is fixedly connected to the drive shaft for rotation therewith, and the second set of blades is fixedly connected to the outer rotor for rotation therewith. The counter-rotating electric motor further includes a motor controller fixed relative to a first one of the inner and outer rotors for rotation therewith, the motor controller being arranged to provide an electric current to the first one of the inner and outer rotors to rotate the inner and outer rotors in opposite directions.

Drawings

Embodiments of the invention will now be described, by way of non-limiting example, with reference to the following drawings, in which:

figure 1 shows a schematic view of a first arrangement of a counter-rotating fan drive assembly,

FIG. 2 shows a schematic view of a second arrangement for a counter-rotating fan drive assembly, an

Fig. 3 shows a schematic view of a third arrangement for a counter-rotating fan drive assembly.

Drawings

Fig. 1 shows a schematic view of a first arrangement of a counter-rotating fan drive assembly 100. Counter-rotating fan drive assembly 100 includes a first impeller 101, a second impeller 102, and a counter-rotating motor 103. Then, the counter-rotating electric motor 103 includes a drive shaft 104, an inner rotor 105, and an outer rotor 106. The inner rotor 105 is fixedly connected to the drive shaft 104, while the outer rotor 106 is arranged to rotate relative to the drive shaft 104. Then, the first impeller 101 is fixedly connected to the drive shaft 104 to rotate together therewith, and the second impeller 102 is fixedly connected to the outer rotor 106 to rotate together therewith. Then, counter-rotating electric motor 103 further includes a motor controller 107 configured to control electric motor 103 by controlling the supply of current to one of inner rotor 105 and outer rotor 106. In particular, motor controller 107 is arranged to provide electronic commutation to electric motor 103 and to control the speed of electric motor 103.

In the arrangement shown in fig. 1, the outer rotor 106 comprises electromagnets 108, while the inner rotor 105 comprises permanent magnets 109. The motor controller 107 is fixed relative to the outer rotor 106 such that when the drive assembly 100 is in use, the motor controller 107 rotates with the outer rotor 106 and the motor controller 107 is in electrical contact with the outer rotor 106 to provide current to the electromagnets 108. In use, the outer rotor 106 generates a magnetic field in response to current received from the motor controller 107, thereby creating a magnetic interaction between the outer rotor 106 and the inner rotor 105, which then rotates the inner rotor 106 and the outer rotor 105 in opposite directions due to the principle of conservation of angular momentum. Thus, the inner rotor 105 may be considered substantially identical to the rotor of a conventional electric motor, while the outer rotor 106 may be considered a rotatably mounted stator. Thus, in use, the first impeller 101 rotates with the drive shaft 104 and the inner rotor 105 in a first direction, while the second impeller 102 rotates with the outer rotor 106 in an opposite second direction.

Counter-rotating electric motor 103 also includes a motor mount assembly 110 arranged to support counter-rotating electric motor 103 and allow counter-rotating electric motor 103 to be mounted or secured to another object. Accordingly, the drive shaft 104 is rotatably mounted to the motor mounting assembly 110 by a plurality of bearings 111. In particular, a first end of the drive shaft 104 is rotatably mounted to the motor mounting assembly 110, while the first impeller 101 is fixedly connected to an opposite second end of the drive shaft 104. The inner rotor 105 is then arranged between the first and second ends of the drive shaft 104.

In the arrangement shown in fig. 1, the outer rotor 106 comprises a rotor housing 112 rotatably mounted to the drive shaft 104 by a plurality of bearings 113, and the electromagnet 108 is fixedly connected to or mounted within the rotor housing 112, and the motor controller 107 is fixedly connected or attached to the rotor housing 112. The second impeller 102 is then fixedly attached to the exterior of the rotor housing 112. Then, the electric rotating motor 103 is provided with a sliding electric contact assembly through which electric power is supplied to the motor controller 107. The sliding electrical contact assembly comprises a fixed part 114 fixedly connected to the motor mounting assembly 110 and a rotatable part 115 fixedly connected to the outer rotor 106, the fixed part 114 being in electrical contact with the rotatable part 115. For example, the fixed portion 114 may include one or more electrical wipers, while the rotatable portion 115 may include one or more conductive loops or traces that are contacted by the wipers. The fixed part 214 is then arranged to receive power from a power source (not shown).

In the particular arrangement shown in fig. 1, drive assembly 100 also includes a main housing 120 that forms a conduit 121 that defines an annular air flow path extending through drive assembly 100. The duct 121 is arranged with its longitudinal axis collinear with the axis of rotation (X) of the counter-rotating fan drive assembly 100. The guide tube 121 includes: a first end defining an annular air inlet 122 through which the drive assembly 100 is configured to draw air into the conduit 121; and a second end opposite the first end and defining an annular air outlet 123 where air that has been processed by the drive assembly 100 is exhausted from the conduit 121. An annular air flow path is then provided between the inner surface of the main housing 120 and the radially outer surface of the hub or rear shroud of each of the first and

second impellers

101, 102 and the radially outer surface of the inner portion 124 of the main housing 120 adjacent the second impeller 102. The motor mounting assembly 110 is then attached to the interior 124 of the main housing 120 such that the first impeller 101, the second impeller 102 and the counter-rotating motor 103 are coaxially supported within the conduit 121. The first impeller 101 then also comprises a cover 116 for directing the incoming air towards the annular air inlet 122, while the outer surface of the interior 124 of the main housing 120 carries a stator cover 125 shaped to ensure smooth outflow of air from the annular air outlet 123.

Fig. 2 shows a schematic view of a second arrangement of counter-rotating fan drive assemblies 200. Counter-rotating fan drive assembly 200 of fig. 2 includes a first impeller 201, a second impeller 202 and a counter-rotating electric motor 203. Then, the counter-rotating electric motor 203 includes a drive shaft 204, an inner rotor 205, and an outer rotor 206. The inner rotor 205 is fixedly connected to the drive shaft 204, while the outer rotor 206 is arranged to rotate relative to the drive shaft 204. Then, the first impeller 201 is fixedly connected to the drive shaft 204 to rotate therewith, and the second impeller 202 is fixedly connected to the outer rotor 206 to rotate therewith. Then, the counter-rotating electric motor 203 further comprises a motor controller 207, the motor controller 107 being configured to control the electric motor 203 by controlling the supply of current to one of the inner rotor 205 and the outer rotor 206. In particular, motor controller 207 is arranged to provide electronic commutation to electric motor 203 and to control the speed of electric motor 203.

In the arrangement shown in fig. 2, inner rotor 205 comprises electromagnets 208 and outer rotor 206 comprises permanent magnets 209. Motor controller 207 is fixed relative to inner rotor 205 such that when the drive assembly is in use, motor controller 207 rotates with inner rotor 205 and motor controller 107 is in electrical contact with inner rotor 205 to provide current to electromagnet 208. In use, inner rotor 205 generates a magnetic field in response to current received from motor controller 207, thereby creating a magnetic interaction between inner rotor 205 and outer rotor 206, which then causes inner rotor 205 and outer rotor 206 to rotate in opposite directions due to the principle of conservation of angular momentum. Thus, outer rotor 206 may be considered substantially identical to the rotor of a conventional electric motor, while inner rotor 205 may be considered a rotatably mounted stator. Thus, in use, first impeller 201 rotates in a first direction with drive shaft 204 and inner rotor 205, while second impeller 202 rotates in an opposite second direction with outer rotor 206.

Counter-rotating electric motor 203 also includes a motor mount assembly 210 arranged to support counter-rotating electric motor 203 and allow counter-rotating electric motor 203 to be mounted or secured to another object. Thus, the drive shaft 204 is rotatably mounted to the motor mounting assembly 210 by a plurality of bearings 211. In particular, a first end of the drive shaft 204 is rotatably mounted to the motor mounting assembly 210, while the first impeller 201 is fixedly connected to an opposite second end of the drive shaft 204. Inner rotor 205 is then disposed between the first and second ends of drive shaft 204.

In the arrangement shown in fig. 2, the outer rotor 206 comprises a rotor housing 212 rotatably mounted to the drive shaft 204 by a plurality of bearings 213, and the second impeller 202 is fixedly connected to or mounted outside the rotor housing 212. The inner rotor 205 then includes a support 216 fixedly connected to the drive shaft 204, while the motor controller 207 is fixedly connected or mounted to the support 216. The electric rotating motor 203 is then provided with a sliding electrical contact assembly through which electrical power is provided to the motor controller 207. The sliding electrical contact assembly includes a fixed portion 214 fixedly connected to the motor mounting assembly 210 and a rotatable portion 215 fixedly connected to the inner rotor 205, the fixed portion 214 being in electrical contact with the rotatable portion 215. For example, the fixed portion 214 may include one or more electrical wipers, while the rotatable portion 215 may include one or more conductive loops or traces that are contacted by the wipers. The fixed part 214 is then arranged to receive power from a power source (not shown).

In the particular arrangement shown in fig. 2, the drive assembly 200 also includes a main housing 220 that forms a conduit 221 defining an annular air flow path extending through the drive assembly 200. The duct 221 is arranged with its longitudinal axis collinear with the axis of rotation (X) of the counter-rotating fan drive assembly 200. The guide duct 221 includes: a first end defining an annular air inlet 222 through which the drive assembly 200 is configured to draw air into the conduit 221; and a second end opposite the first end and defining an annular air outlet 223 where air that has been processed by the drive assembly 200 is exhausted from the conduit 221. An annular air flow path is then provided between the inner surface of the main housing 220 and the radially outer surface of the hub or rear shroud of each of the first and

second impellers

201, 202 and the radially outer surface of the inner portion 224 of the main housing 120 adjacent the second impeller 202. The motor mounting assembly 210 is then attached to the interior 224 of the main housing 220 such that the first impeller 201, the second impeller 202 and the counter-rotating motor 203 are coaxially supported within the conduit 221. The first impeller 201 then also includes a cover 217 for directing incoming air towards the annular air inlet 222, while the outer surface of the interior 224 of the main housing 220 carries a stator cover 225, the shape of the stator cover 125 ensuring a smooth outflow of air from the annular air outlet 223.

Next, fig. 3 shows a schematic diagram of a third arrangement for counter-rotating fan drive assembly 100 a. This third arrangement is similar to that of the first arrangement and so corresponding reference numerals have been used for the same or corresponding parts or features of these arrangements. The only significant difference between the first and third arrangements is that the counter-rotating motor 103 of the third arrangement further comprises an on-board battery 130 arranged to provide an electrical current for energising the motor 103. Specifically, the battery 130 is fixed relative to the motor controller 107 to rotate therewith, and is in electrical contact with the motor controller 107 so as to provide current to the motor controller 107. In use, the motor controller 107 controls the current received from the battery 130 to be supplied to one of the inner rotor 105 and the outer rotor 106. The inclusion of the on-board battery 130 in the counter-rotating fan drive assembly 100a provides that the counter-rotating fan drive assembly 100a can be operated when disconnected from any external power source and is therefore suitable for use in portable devices.

The counter-rotating fan drive assembly 100a is then arranged to allow the battery 130 to be charged when not in use. In the arrangement of fig. 3, the counter-rotating motor 103 is provided with sliding

electrical contact assemblies

114, 115 through which power may be provided to charge the battery 130. However, in alternative arrangements, other means, such as wireless power transfer, may be used to effect recharging of the battery 130.

In the arrangement of fig. 3, the outer rotor 106 includes electromagnets 108 and the inner rotor 105 includes permanent magnets 109, such that both the battery 120 and the motor controller 107 are fixed relative to the outer rotor 106 so that they rotate with the outer rotor 106. However, in yet another arrangement, the counter-rotating fan drive assembly may be substantially the same as the second arrangement, wherein the inner rotor 205 includes an electromagnet 208, so that both the battery and the motor controller will be fixed relative to the inner rotor 205 such that they rotate with the inner rotor 205.

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, the embodiments described above all relate to a counter-rotating drive assembly for driving a fan, and therefore include a first counter-rotating impeller and a second counter-rotating impeller, where the impellers are rotating components 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.

For example, in the arrangement of fig. 3, the battery is positioned concentrically around the electromagnet. However, this is not essential. In particular, the battery may be positioned such that the electromagnet is arranged concentrically around the battery. Alternatively, the battery may be located on one side of the electromagnet such that the battery is either closer to the first end of the drive shaft than the electromagnet (e.g., between the electromagnet and the motor mounting assembly) or closer to the second shaft of the drive shaft than the electromagnet (e.g., between the electromagnet and the first impeller). Additionally, the counter-rotating fan drive assembly may include a plurality of batteries arranged to cooperate to provide an electrical current for energizing the motor. A plurality of batteries are distributed around the electromagnet. For example, a plurality of batteries may be distributed circumferentially around the outside of the electromagnet and/or one side of the electromagnet.

Claims

1. A counter-rotating fan drive assembly comprising:

a first impeller;

a second impeller; and

a contra-rotating electric motor comprising a drive shaft, an inner rotor fixedly connected to the drive shaft, and an outer rotor arranged for rotation relative to the drive shaft;

wherein the first impeller is fixedly connected to the drive shaft for rotation therewith and the second impeller is fixedly connected to the outer rotor for rotation therewith; and is

Wherein the counter-rotating motor comprises a battery fixed relative to a first one of the inner and outer rotors for rotation therewith, the battery being arranged to provide current to the first one of the inner and outer rotors to rotate the inner and outer rotors in opposite directions.

2. A counter-rotating fan drive assembly according to claim 1, wherein the counter-rotating motor includes a motor controller fixed relative to the battery for rotation therewith, the motor controller being arranged to receive current from the battery and control the supply of current to a first one of the inner and outer rotors.

3. A counter-rotating fan drive assembly according to claim 1 or 2, wherein the counter-rotating motor includes a motor mounting assembly and the drive shaft is rotatably mounted to the motor mounting assembly.

4. The counter-rotating fan drive assembly according to claim 3, wherein a first end of the drive shaft is rotatably mounted to the motor mounting assembly and the first impeller is fixedly connected to an opposite second end of the drive shaft.

5. The contra-rotating fan drive assembly according to claim 4, wherein the inner rotor is disposed between the first and second ends of the drive shaft.

6. A contra-rotating fan drive assembly according to any of claims 1 to 5, wherein the outer rotor is disposed concentrically about the inner rotor.

7. The counter-rotating fan drive assembly according to any one of claims 1 to 6, wherein the outer rotor comprises a rotor housing rotatably mounted to the drive shaft and the second impeller is fixedly connected to the rotor housing.

8. The counter-rotating fan drive assembly according to claim 7, wherein the battery is fixedly connected to the rotor housing.

9. The counter-rotating fan drive assembly according to claim 8, wherein the motor controller is fixedly connected to the rotor housing.

10. A contra-rotating fan drive assembly according to any of claims 1 to 9, wherein the inner rotor comprises permanent magnets and the outer rotor comprises electromagnets.

11. A contra-rotating fan drive assembly according to any of claims 1 to 9, wherein the inner rotor comprises electromagnets and the outer rotor comprises permanent magnets.

12. A counter-rotating fan drive assembly comprising:

a first set of blades;

a second set of blades; and

wherein the first set of blades is fixedly connected to the drive shaft for rotation therewith and the second set of blades is fixedly connected to the outer rotor for rotation therewith; and is