CN117662496A - Knapsack formula hair-dryer - Google Patents

Abstract

The application provides a knapsack type blower, which comprises a shell component, a knapsack device, a motor and a fan; the shell component comprises an air pipe, an air inlet and a main air channel communicated with the air inlet and the air pipe, and the motor and the fan are arranged in the main air channel; the shell component is also provided with a heat dissipation air duct communicated with the main air duct, and the bearing device is provided with a bearing heat dissipation air hole communicated with the heat dissipation air duct; the fan is in transmission connection with the motor, so that first air flow and second air flow which are converged in the main air duct and exhausted by the air duct are generated under the driving of the motor, the first air flow is converged into the main air duct from the air inlet, and the second air flow is converged into the main air duct from the backpack cooling air duct through the cooling air duct. The knapsack type air blower provided by the invention can provide good back heat dissipation effect for a user during working, and improves the comfort level.

Description

Knapsack formula hair-dryer

Technical Field

The application relates to the technical field of blowers, in particular to a knapsack type blower.

Background

In the use of knapsack formula hair-dryer, because the weight of machine itself is heavier, professional user is being carried on the hair-dryer all the time when carrying out actual work and is consuming great to physical power, and its back is hugged closely with the human body, and operating time has been for a long time or when the weather is hotter leads to user's back to sweat easily, feels obvious uncomfortable, influences work efficiency. Therefore, the back cooling problem of the user needs to be considered in the design of the backpack blower.

Existing backpack blowers are largely classified into centrifugal and axial flow type blowers according to the type of fans therein. For a centrifugal blower, the main method for cooling the back of a user is to cool the back by using a centrifugal fan of the blower; the air inlet of the fan is arranged on the machine carrying device, when the fan is started to blow, air convection can be formed through negative pressure generated when the fan runs at a high speed, air flows in from a gap between the machine carrying device and the back of a human body and is sucked through the air inlet of the fan, and the generated air inlet has a cooling effect on the back of the human body. The above solution has some drawbacks: 1. the centrifugal fan is usually driven by a gasoline engine, so that the centrifugal blower is generally integrated with the gasoline engine, the whole size and the weight are large, the burden of a user is heavy when the user carries the centrifugal fan, and the noise generated when the gasoline engine and the centrifugal fan work is serious. 2. Because the air inlet of the fan, namely the inlet of the main air duct, is arranged on the carrying device, the inlet of the main air duct is opposite to the back of a user during use, and the air suction quantity of the main air duct is large, the main air duct can be possibly overruled during cooling by the fan, so that the user feels cold, and the main air duct is also harmful to health. On the other hand, for axial flow type hair dryer, because it adopts pure electric drive generally, compare lighter in weight, the size is less than centrifugal hair dryer, but because its wind-force is less relatively, generally can not give attention to the back heat dissipation function of user when blowing, and operating personnel is when carrying the use, and the back is difficult to in time dispel the heat, and use experience is also not ideal enough.

Accordingly, there is a need to provide a more novel backpack blower that addresses the above-described problems of the prior art.

Disclosure of Invention

Accordingly, the present invention is directed to a backpack blower, which is capable of reducing the size, weight and noise compared to the prior art, and providing a user with a good back heat dissipation during operation.

One preferred embodiment of the present invention provides a backpack blower comprising a housing assembly, a backpack device, a motor and a fan; the shell component comprises an air pipe, an air inlet and a main air channel communicated with the air inlet and the air pipe, and the motor and the fan are arranged in the main air channel; the shell component is also provided with a heat dissipation air duct communicated with the main air duct, and the bearing device is provided with a bearing heat dissipation air hole communicated with the heat dissipation air duct; the fan is in transmission connection with the motor, so that first air flow and second air flow which are converged in the main air duct and exhausted by the air duct are generated under the driving of the motor, the first air flow is converged into the main air duct from the air inlet, and the second air flow is converged into the main air duct from the backpack cooling air duct through the cooling air duct.

In some embodiments, the casing assembly is further provided with a first connection air hole, and the heat dissipation air duct is communicated with the main air duct through the first connection air hole.

In some embodiments, the ventilation area of the piggyback cooling air hole is greater than the ventilation area of the first connecting air hole.

In some embodiments, the casing component is further provided with a second connection air hole, the second connection air hole is used for being in butt joint with the backpack heat dissipation air hole, and the second air flow is converged into the main air duct through the second connection air hole, the heat dissipation air duct and the first connection air hole by the backpack heat dissipation air hole.

In some embodiments, the enclosure assembly includes a duct and a main housing surrounding the duct, the duct and the main housing enclosing the heat dissipation duct.

In some embodiments, the ventilation area of the piggyback cooling air hole, the ventilation area of the second connection air hole, and the ventilation area of the first connection air hole decrease in sequence.

In some embodiments, the housing assembly further comprises a wind scooper, the first air flow flows into the main air duct through the wind scooper, the first connection air hole is formed in the wind scooper, and the second air flow is converged into the main air duct through the wind scooper by the first connection air hole.

In some embodiments, the first connection wind hole includes a plurality of ventilation holes, and the plurality of ventilation holes are spaced apart in an extending direction of the main wind channel.

In some embodiments, the first connection port is open within 30mm-80mm upstream of the fan.

In some embodiments, the backpack blower further comprises a guide cone, the fan and the guide cone are respectively arranged at two sides of the motor, and the position of the backpack radiating wind hole on the backpack device is located between the projection of the fan on the backpack device and the projection of the guide cone on the backpack device.

In some embodiments, a first interval is arranged between an intersection point of a bearing plane of the bearing device and a central shaft of the air pipe and the bearing heat dissipation air hole, and the projection length of the first interval on the bearing plane is 260-360 mm.

In some embodiments, the backpack blower further comprises a battery pack for powering the motor, the battery pack is disposed on the backpack device and above the housing assembly, and the second distance between the backpack cooling air hole and the bottom side of the battery pack is 25mm-55mm.

In some embodiments, the backpack blower further comprises a strap connected to the backpack device, a drainage slot being formed between the strap and the backpack device for guiding the second air flow.

In some embodiments, the backpack cooling air hole is in the form of a louver.

In some embodiments, the fan is an axial fan and the motor is a dc motor.

The backpack blower solution provided by the above preferred embodiment of the present invention has various advantages over the prior art. Firstly, this scheme produces simultaneously with lighter weight, less, the little direct current motor of size and the axial fan of noise and is used for blowing first air current and the second air current that is used for giving the user's back heat dissipation, has realized the purpose of giving the user's back heat dissipation when blowing, compares in lacking the traditional axial fan of back heat dissipation function and can provide the back heat dissipation function but weight, size and noise are all great traditional centrifugal blower all have better use experience. Secondly, the back carrying device is arranged to be parallel or basically parallel to the axis of the main air duct, in particular the duct, of the shell assembly, and to be vertical or basically vertical to the plane of the air inlet, i.e. the inlet of the main air duct; that is, the inlet position of the main air duct of the blower is not provided on the carrying device, but is provided on the side of the carrying device in a plane substantially perpendicular to the carrying device. When a user carries the blower, the inlet of the main air duct is positioned in a plane basically perpendicular to the back of the user, and is not right opposite to the back of the user, and only a small carrying heat dissipation air hole is right opposite to the back of the user for heat dissipation; meanwhile, the backpack device is parallel to the axis of the main air duct, so that the backpack device is separated from the main air duct by a certain distance; these arrangements can avoid excessive inhalation flow from blowing over the back of the user and causing them to feel cold, and are therefore suitable for use in both hot and cold days. Third, the relative orientation of the back-carried heat dissipation air hole, the fan and the guide cone is set to be the position of the back-carried heat dissipation air hole on the back-carried device and the projection of the fan on the back-carried device and the guide cone on the back-carried device, so that the structural arrangement of the whole machine is better mutually adapted to the gravity center distribution of the whole machine, and a user can obtain reasonable body load distribution and good back heat dissipation effect simultaneously.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view showing an external structure of a backpack blower according to a preferred embodiment of the present application.

Fig. 2 is a schematic view of the external structure of the backpack blower of fig. 1 at another viewing angle.

Fig. 3 is an exploded schematic view of the backpack blower of fig. 1 (only a portion of the air duct is shown for ease of viewing due to the longer length of the air duct).

Fig. 4 is a schematic view of a partial longitudinal cross-sectional structure of the backpack blower shown in fig. 1.

Fig. 5 is a schematic diagram of the operating principle of the backpack blower shown in fig. 1.

Fig. 6 is a schematic view of the backpack blower of fig. 1 after straps are provided on the backpack.

Detailed Description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art without making any inventive effort, are intended to be within the scope of the present invention.

Referring to fig. 1, 2, 3 and 4, a preferred embodiment of the present application provides a backpack blower, which includes a housing assembly 1, a backpack device 2, a motor 3, and a fan 4.

The casing assembly 1 comprises a first casing 11, a second casing 12 and a duct 10, wherein the first casing 11 is provided with a first main casing 111 which is approximately rectangular, and one end of the first main casing 111 is outwards expanded to form a half-horn-shaped first air guiding casing 112; the second casing 12 has a second main casing 121 having a substantially semi-cylindrical shape, and one end of the second main casing 121 is outwardly expanded to form a half-horn-shaped second air guiding housing 122. The shapes and sizes of the first casing 11 and the second casing 12 correspond to each other, the first casing 11 and the second casing 12 are fastened together relatively and fixed by means of welding, bonding, fastening connection, etc. in the prior art, the first casing 11 and the second casing 12 can be assembled together, wherein the first main casing 111 and the second main casing 121 enclose a main casing 1a for accommodating the duct 13, and the first air guiding casing 112 and the second air guiding casing 122 form an outwardly flared inlet casing 1b. The opening of the inlet housing 1b forms the air intake of the backpack blower. The duct 10 is substantially cylindrical and fixedly arranged inside the main casing 1 a; the outer surface of the duct 10 is separated from the inner surface of the main casing 1a by a certain gap, so that the duct 13 and the main casing 1a enclose a heat dissipation air duct 110 (as shown in fig. 5); the inner space of the duct 10 is for accommodating the motor 3 and the fan 4.

The shell component 1 also comprises an air guide cover 13, an air inlet net cover 14 and an air pipe 15. The wind scooper 13 may be a horn-shaped housing, preferably made of a sound insulating material such as sound insulating plastic or sponge, etc., installed inside the inlet housing 1b for guiding the air flow sucked into the air inlet. The size of the air guide cover 13 corresponds to the inlet housing 1b but the outer diameter is smaller than the inner diameter of the inlet housing 1b, so that the air guide cover 13 can be accommodated in the inlet housing 1b while a certain gap is formed between the outer surface of the air guide cover 13 and the inner surface of the inlet housing 1b. The first connection air holes 130 are formed in the air guide cover 13, and in this embodiment, the first connection air holes 130 are preferably formed as a plurality of air holes or other similar structures, and the plurality of air holes are arranged in a line along an axial direction of the air guide cover 13, that is, at intervals along an extending direction of a main air duct described below, and the arrangement is helpful for preventing the air guide cover 13 from being deformed. When the wind scooper 13 is installed inside the inlet housing 1b, it is preferable to orient the plurality of first connection wind holes 130 toward the first casing 11. The air inlet net cover 14 can be arranged at the air inlet and is mutually fixed with the inlet shell 1b or the air guide cover 13, so as to prevent sundries from being sucked in when the blower works. The air duct 15 is connected to the ends of the first casing 11 and the second casing 12, which are far away from the air guide cover 13, so that the air guide cover 13, the duct 10 and the air duct 15 are mutually communicated to form a main air duct of the backpack blower, and the heat dissipation air duct 110 is communicated with the main air duct through the first connection air hole 130. The end of the air duct 15 forms a main duct outlet for discharging the blast air.

In this embodiment, the chassis assembly 1 further has a second connection air hole 113, and the second connection air hole 113 communicates with the first connection air hole 130 via the heat dissipation air duct 110 (as shown in fig. 5). The shape of the second connection wind hole 113 may be a single or a plurality of circular holes, or a louver design, and the second connection wind hole 113 is preferably formed as a plurality of circular holes in the present embodiment to be provided on the side surface of the first main housing 11.

The knapsack device 2 is in a flat plate shape and is fixedly connected with the shell assembly 1, a user can knapsack the whole knapsack type blower through the knapsack device 2, the outer side surface of the knapsack device 2 is opposite to the back of the user in the state, and the knapsack type blower can be stably supported on the back of the user. The knapsack device 2 is provided with knapsack heat dissipation air holes 20 penetrating through the surfaces of two opposite sides of the knapsack device for dissipating heat to the back of a user, and the knapsack heat dissipation air holes 20 are preferably in a shape of a single round hole or a square hole or a hidden shutter design, and in the embodiment, the hidden shutter design is preferred. In the present embodiment, it is preferable that the back carrying device 2 is fixedly connected to a side of the first main casing 11 remote from the second main casing 12 such that the back carrying device 2 and the second main casing 12 are respectively disposed at opposite sides of the first main casing 11, and the back carrying device 2 is disposed to be parallel or substantially parallel to the axis of the main air duct, particularly the duct 10, and to be perpendicular or substantially perpendicular to the plane of the air intake, i.e., the inlet of the main air duct, while the back carrying heat dissipating air hole 20 is butted with the second connecting air hole 113 such that the back carrying heat dissipating air hole 20 communicates with the heat dissipating air duct 110 in the housing assembly 1. It is particularly preferred that in this embodiment a first distance is also provided between the intersection of the back carrying plane of the back carrying device 2 (i.e. the plane formed on the back carrying device 2 that is in abutment with the back of the user when the user carries the backpack blower) and the central axis of the air duct 15 and the back carrying cooling air hole 20, said first distance forming a projection of length of 260mm-360mm along the extension of the back carrying plane, which design facilitates a rational distribution of the back carrying weights. In other embodiments, the carrying device 2 may be a waist plate that only abuts against the waist of the operator, a back plate that only abuts against the back of the operator, or other structures for carrying the operator, such as a back frame, without being limited thereto.

The motor 3 is preferably a direct current motor. The fan 4 is preferably an axial fan and is mounted coaxially with the motor 3 at one end of the motor 3 so as to be in driving connection with the motor 3 and capable of rotating under the drive of the motor 3. When the motor 3 and the fan 4 are mounted in the duct 10, the fan 4 is preferably mounted closer to the air guide cover 13 than the motor 3, while the area of the air guide cover 14 where the first connection air holes 130 are opened is located between the fan 4 and the air intake screen 14.

The backpack blower of this embodiment may further include a battery pack 5 and a guide cone 6, wherein the battery pack 5 may be mounted on the backpack device 2 and electrically connected to the motor 4 for providing power to the motor 4. It will be appreciated that the mounting position of the battery pack 5 on the carrying device 2 should be offset from the position of the carrying heat dissipation air holes 20 so as not to block the air flow through the carrying heat dissipation air holes 20. The cone 6 may be provided at the end of the motor 3 remote from the fan 4 with its tip facing the air duct 15 for improved air flow distribution. In the present embodiment, the positions of the fan 4 and the flow cone 6 are preferably set such that their projections onto the carrying device 2 are located on both sides of the carrying heat dissipation air holes 20, respectively, that is, such that the position of the carrying heat dissipation air holes 20 on the carrying device 2 is located between the projection of the fan 4 onto the carrying device 2 and the projection of the flow cone 6 onto the carrying device 2.

Referring to fig. 5, the main operation principle of the backpack blower is shown: when the backpack type blower works, the motor 3 drives the fan 4 to rotate, negative pressure is formed in the air guide cover 13, so that external air is sucked into the air guide cover 13 from the air inlet net cover 14, and finally blown out from the air pipe 15 through the flow guiding treatment of the flow guiding cone 6 when passing through the duct 10, so that first air flow which is converged into the main air channel through the air guide cover 13 by the air inlet is formed, and the conventional blowing function is realized. Meanwhile, the negative pressure formed in the air guiding cover 13 also sucks the air beside the first connecting air hole 130 on the side surface of the air guiding cover 13 into the air guiding cover 13, and the first connecting air hole 130 is communicated with the knapsack heat dissipation air hole 20 through the heat dissipation air duct 110 and the second connecting air hole 113, so that the fan 4 can sequentially pass through the first connecting air hole 130, the heat dissipation air duct 110, the second connecting air hole 113 and the knapsack heat dissipation air hole 20 to suck the air outside the knapsack device 2 to form a second air flow. When the user wears the backpack blower, the back of the user faces the outer side surface of the backpack 2, and the second air flow can flow through the back of the user for dissipating heat from the back of the user. In addition, after the second air flows through the back-carrying heat dissipation air hole 20, the second connection air hole 113 and the heat dissipation air duct 110 in sequence, the second air finally passes through the air guide cover 13 through the first connection air hole 130 and merges with the first air in the main air duct, which is helpful for enhancing the air blowing effect.

The backpack blower solution provided by the above embodiments has various advantages over the prior art. Firstly, the motor 4 and the axial fan 3 which are lighter in weight, smaller in size and smaller in noise are used for simultaneously generating the first air flow for blowing and the second air flow for radiating the back of the user, so that the purpose of radiating the back of the user while blowing is achieved, and compared with the traditional axial fan which lacks the back radiating function and the traditional centrifugal fan which can provide the back radiating function but is heavier in weight, size and noise, the centrifugal fan has better use experience. Secondly, the backpack device 2 is arranged in the present embodiment parallel or substantially parallel to the axis of the main duct of the housing assembly 1, in particular duct 10, and perpendicular or substantially perpendicular to the plane of the inlet opening, i.e. the inlet of the main duct; that is, the inlet position of the main air duct of the blower is not provided on the carrying device 2, but is provided on the side of the carrying device 2 in a plane substantially perpendicular to the carrying device 2. Thus, when the user wears the blower, the inlet of the main air duct is positioned in a plane basically vertical to the back of the user, and the main air duct is not over against the back of the user, and only one smaller backpack heat dissipation air hole 20 is over against the back of the user for heat dissipation; meanwhile, the backpack device 2 is parallel to the axis of the main air duct, so that a certain distance is also separated from the main air duct; these arrangements can avoid excessive inhalation flow from blowing over the back of the user and causing them to feel cold, and are therefore suitable for use in both hot and cold days. Third, the relative orientation of the back-carried heat dissipation air hole 20, the fan 4 and the guide cone 6 is set to be that the position of the back-carried heat dissipation air hole 20 on the back-carried device 2 is located between the projection of the fan 4 on the back-carried device 2 and the projection of the guide cone 6 on the back-carried device 2, so that the structural arrangement of the whole machine is better mutually adapted to the gravity center distribution of the whole machine, and a user can obtain reasonable body load distribution and good back heat dissipation effect.

In some embodiments, in order to further improve the back heat dissipation effect in the above-mentioned solution, it is preferable that the ventilation area of the back heat dissipation air hole 20, the ventilation area of the second connection air hole 113 (if the number of the second connection air holes 113 is plural, the ventilation area thereof refers to the sum of the ventilation areas of the plural second connection air holes 113), and the cross-sectional area of the first connection air hole 130 (if the first connection air hole 130 is designed as the plural ventilation holes as described above, the ventilation area thereof refers to the sum of the ventilation areas of the plural ventilation holes thereof) are set to be sequentially reduced, so that the air flow pressure sequentially passing through the back heat dissipation air hole 20, the second connection air hole 113, and the first connection air hole 130 is gradually changed, thereby forming a certain pressure difference between the first connection air hole 130 and the back heat dissipation air hole 20, contributing to increasing the flow rate of the second air flow, and further improving the air suction effect.

In some embodiments, the first connection air hole 130 is preferably formed within 30mm-80mm upstream of the fan, and specifically, the length of the straight line along which the plurality of air holes of the first connection air hole 130 are arranged along the axial direction of the air guiding cover 13 may be set to be within a range of 30-80 mm from the horizontal distance of the maximum outer diameter of the blades of the fan 4, which is beneficial to further improving the air suction and heat dissipation effects.

In some embodiments, to further improve the back heat dissipation effect and the back carrying experience of the blower, the back carrying heat dissipation air holes 20 may be arranged within a height range of 30-60mm above the central axis of the main air duct, while the battery pack 5 is arranged above the housing assembly 1, preferably the second distance between the bottom of the battery pack 5 and the back carrying heat dissipation air holes 20 is arranged within a range of 25-55 mm. Therefore, the air inlet of the back carrying heat dissipation air hole 20 can be effectively prevented from being blocked, and the lifting of the center of gravity of the whole machine caused by the overhigh height of the battery pack can be prevented, so that the back carrying experience is deteriorated.

In some embodiments, to further improve the back heat dissipation effect and the back carrying experience of the blower, one or more of the following structural arrangements may also be employed: the first connecting wind hole 130 is arranged above the horizontal plane where the core center of the motor 3 is located and between the blades of the fan 4 and the air inlet net cover 14; the first connecting wind hole 130 is arranged at one side of the fan 4, and the back carrying heat dissipation wind hole 20 and the second connecting wind hole 113 are arranged at the other side of the fan 4 opposite to the first connecting wind hole 130; the positions of the back carrying heat dissipating wind hole 20 and the second connecting wind hole 113 are set so that the horizontal distance from the maximum outer diameter of the blades of the fan 4 is not more than 50mm and the vertical distance from the core center of the motor 3 is between 39 and 50 mm.

Referring to fig. 6, in some embodiments, the backpack blower further includes a back strap 7 connected to the backpack device 2, and the user can carry the backpack blower on the back through the back strap 7, and the back strap 7 can space the backpack device 2 from the back of the user, so as to allow the outside air to enter the backpack cooling air hole 20 without obstruction.

In some embodiments, a drainage slot (not shown in the figure) for guiding the second air flow may be formed between the back strap 7 and the back carrying device 2, and the external air flow may be guided between the back carrying device 2 and the back of the user when the blower is in use, so as to provide a source for the second air flow. The backpack 2 may further be provided with an auxiliary fan assembly (not shown) which blows air directly towards the rear of the user to assist in heat dissipation when the blower is in use, and which is preferably electrically connected to the battery pack 5, and is powered by the battery pack 5.

The present invention is not limited to the above embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention. Accordingly, the scope of the invention should be assessed as that of the appended claims.

Claims (15)

1. A backpack blower, wherein the backpack blower comprises a housing assembly, a backpack device, a motor and a fan; the shell component comprises an air pipe, an air inlet and a main air channel communicated with the air inlet and the air pipe, and the motor and the fan are arranged in the main air channel; the shell component is also provided with a heat dissipation air duct communicated with the main air duct, and the bearing device is provided with a bearing heat dissipation air hole communicated with the heat dissipation air duct; the fan is in transmission connection with the motor, so that first air flow and second air flow which are converged in the main air duct and exhausted by the air duct are generated under the driving of the motor, the first air flow is converged into the main air duct from the air inlet, and the second air flow is converged into the main air duct from the backpack cooling air duct through the cooling air duct.

2. The backpack blower of claim 1, wherein the housing assembly further comprises a first connecting port, the heat dissipation duct being connected to the main duct by the first connecting port.

3. The backpack blower of claim 2 wherein the backpack cooling air hole has a greater ventilation area than the first connecting air hole.

4. The backpack blower of claim 2, wherein the housing assembly is further provided with a second connecting air hole, the second connecting air hole being configured to interface with the backpack cooling air hole, the second air flow being directed into the main air duct by the backpack cooling air hole via the second connecting air hole, the cooling air duct and the first connecting air hole.

5. The backpack blower of claim 4 wherein the housing assembly comprises a duct and a main housing surrounding the duct, the duct and the main housing enclosing the heat dissipation duct.

6. The backpack blower of claim 4 wherein the ventilation area of the backpack cooling air hole, the ventilation area of the second connecting air hole and the ventilation area of the first connecting air hole decrease in sequence.

7. The backpack blower of claim 2, wherein the housing assembly further comprises a hood through which the first air flow flows into the main duct, the first connection air hole being open on the hood, the second air flow passing through the hood from the first connection air hole into the main duct.

8. The backpack blower of claim 2, wherein the first connection air hole comprises a plurality of air holes, the plurality of air holes being spaced apart in the direction of extension of the main air duct.

9. The backpack blower of claim 2 wherein the first connection port opens within 30mm-80mm upstream of the fan.

10. The backpack blower of claim 1, further comprising a flow cone, wherein the fan and the flow cone are disposed on each side of the motor, and wherein the location of the backpack cooling air hole on the backpack device is between the projection of the fan on the backpack device and the projection of the flow cone on the backpack device.

11. A backpack blower according to claim 1 or 10, wherein a first distance is provided between the intersection of the backpack plane of the backpack device and the central axis of the air duct and the backpack cooling air hole, the projection of the first distance on the backpack plane having a length of 260mm-360mm.

12. The backpack blower of claim 1 further comprising a battery pack for powering the motor, the battery pack being disposed on the backpack device above the housing assembly, the second distance between the backpack cooling air hole and the bottom side of the battery pack being 25mm-55mm.

13. The backpack blower of claim 1 further comprising a strap connected to the backpack, the strap and the backpack forming a drainage slot therebetween for guiding the second air flow.

14. The backpack blower of claim 1 wherein the backpack cooling air hole is in the form of a louver.

15. The backpack blower of any one of claims 1-14 wherein the fan is an axial flow fan and the motor is a dc motor.