Patent Description:
As a garden tool, a blower may be used for cleaning the ground. The air intake performance of an air intake portion of the blower limits the blowing efficiency of the blower. When the air intake performance is to be improved, the use safety of the blower and the strength of the whole machine need to be considered and the weight of the whole machine cannot be increased. Therefore, how to improve the air intake performance of the blower is a problem relatively difficult to solve. <CIT> discloses a blower, comprising a motor and a housing assembly accommodating the motor, the housing assembly comprising an inner duct formed with an inner air inlet; an outer duct assembly surrounding the inner duct, wherein the outer duct assembly comprises an outer duct and a hood, wherein the outer duct is disposed on a front side of the hood, wherein an outer air outlet is formed at an end of the outer duct facing away from the hood, wherein an outer air inlet is formed on the hood and has a front end portion and a rear end portion along a direction of the first axis.

The present invention provides a blower, which can improve the blowing efficiency of the blower and reduce the weight of the whole machine and is convenient for a user to hold.

The blower of the present invention includes a motor, a fan, a power supply device, and a housing assembly. The fan is driven by the motor to rotate about a first axis. The power supply device is used for supplying power to the motor. The housing assembly accommodates the motor and includes an inner duct and an outer duct assembly. The inner duct is formed with an inner air inlet. The outer duct assembly surrounds the inner duct. The outer duct assembly includes an outer duct and a hood, where the outer duct is disposed on a front side of the hood, an outer air outlet is formed at an end of the outer duct facing away from the hood, an outer air inlet is formed on the hood and has a front end portion and a rear end portion along a direction of the first axis, and the inner air inlet is disposed between the front end portion and the rear end portion along the direction of the first axis.

In some examples, a distance between the front end portion of the outer air inlet and the inner air inlet along the direction of the first axis is greater than or equal to <NUM>.

In some examples, a distance between the front end portion of the outer air inlet and the inner air inlet along the direction of the first axis is greater than or equal to <NUM> and less than or equal to <NUM>.

In some examples, a ratio of an effective air intake area of the outer air inlet to a cross-sectional area of the inner air inlet perpendicular to the first axis is greater than or equal to <NUM>.

In some examples, the hood includes multiple ribs arranged in sequence in a circumferential direction around the first axis, and the outer air inlet is formed between two adjacent ribs of the multiple ribs.

In some examples, a spacing between two adjacent ribs of the multiple ribs is configured to be greater than or equal to <NUM> and less than or equal to <NUM>.

In some examples, one part of the hood is disposed on a front side of the inner air inlet and the other part of the hood is disposed on a rear side of the inner air inlet so that an airflow entering from the hood is capable of flowing to the inner air inlet from the front side and the rear side of the inner air inlet.

In some examples, a total area of the outer air inlet is greater than <NUM><NUM>.

In some examples, the hood includes first ribs, an annular portion, second ribs, and a central portion arranged in sequence from front to rear, where the annular portion connects the first ribs to the second ribs, the second ribs connect the annular portion to the central portion, and a distance between each of the second ribs and the first axis along a connection path between the annular portion and the central portion gradually decreases.

In some examples, a dimension of the outer air inlet along the direction of the first axis is greater than or equal to <NUM> and less than or equal to <NUM>.

In some examples, the fan includes fan blades, where a number of the fan blades is set to <NUM>.

In some examples, the fan includes fan blades, where a number of the fan blades is configured to be greater than or equal to <NUM> and less than or equal to <NUM>, and an outer diameter of the fan blades is configured to be greater than <NUM> and less than <NUM>.

In some examples, the outer diameter of the fan blades is configured to be greater than <NUM> and less than <NUM>.

In some examples, an inlet angle of each of the fan blades is configured to be greater than or equal to <NUM>° and less than or equal to <NUM>°.

In some examples, a ratio of the outer diameter of the fan blades to a diameter of a hub of the fan is greater than or equal to <NUM> and less than or equal to <NUM>.

In an example of the present invention, referring to <FIG>, a blower <NUM> includes a motor <NUM>, a fan <NUM>, a power supply device <NUM>, and a housing assembly <NUM>. The housing assembly <NUM> includes an outer duct assembly 130a and an inner duct <NUM>, where the outer duct assembly 130a includes an outer duct <NUM> and a hood <NUM>. The fan <NUM> is driven by the motor <NUM> to rotate, and the power supply device <NUM> is used for supplying power to the motor <NUM>. The outer duct assembly 130a provides an outer air inlet <NUM> and an outer air outlet <NUM>. The inner duct <NUM> is used for supporting the motor <NUM> and formed with an inner air inlet <NUM>. The outer duct assembly 130a surrounds the inner duct <NUM>. The outer duct <NUM> is disposed on a front side of the hood <NUM>. One part of the inner duct <NUM> is disposed in the outer duct <NUM>, and the other part of the inner duct <NUM> is disposed in the hood <NUM>. The outer duct <NUM> provides the outer air outlet <NUM>, and the hood <NUM> provides the outer air inlet <NUM>. The hood <NUM> provides the outer air inlet <NUM>, and the hood <NUM> surrounds an end of the inner duct <NUM> so that part of an airflow entering from the hood <NUM> can flow from a rear end portion of the inner duct <NUM> to the inner air inlet <NUM>.

Optionally, it is set that the motor <NUM> rotates about a first axis <NUM>, and the outer air inlet <NUM> has a front end portion 131a and a rear end portion 131b along a direction of the first axis <NUM>. The inner air inlet <NUM> is disposed between the front end portion 131a and the rear end portion 131b along the direction of the first axis <NUM>. In this manner, the airflow can enter the hood <NUM> from a front side and a rear side of the inner air inlet <NUM> separately and then enter the inner air inlet <NUM>.

The hood <NUM> surrounds the inner air inlet <NUM>. In a front and rear direction, one part of the hood <NUM> is disposed on the front side of the inner air inlet <NUM>, and the other part of the hood <NUM> is disposed on the rear side of the inner air inlet <NUM>. In an up and down direction, one part of the hood <NUM> is disposed on an upper side of the inner air inlet <NUM>, and the other part of the hood <NUM> is disposed on a lower side of the inner air inlet <NUM>. In a left and right direction, one part of the hood <NUM> is disposed on a left side of the inner air inlet <NUM>, and the other part of the hood <NUM> is disposed on a right side of the inner air inlet <NUM>. That is to say, the hood <NUM> is distributed on the front side, the rear side, the upper side, the lower side, the left side, and the right side of the inner air inlet <NUM>.

The outer air inlet <NUM> is formed on the hood <NUM> and surrounds the inner air inlet <NUM>. In the front and rear direction, one part of the outer air inlet <NUM> is disposed on the front side of the inner air inlet <NUM>, and the other part of the outer air inlet <NUM> is disposed on the rear side of the inner air inlet <NUM>. In the up and down direction, one part of the outer air inlet <NUM> is disposed on the upper side of the inner air inlet <NUM>, and the other part of the outer air inlet <NUM> is disposed on the lower side of the inner air inlet <NUM>. In the left and right direction, one part of the outer air inlet <NUM> is disposed on the left side of the inner air inlet <NUM>, and the other part of the outer air inlet <NUM> is disposed on the right side of the inner air inlet <NUM>. That is to say, the outer air inlet <NUM> is distributed on the front side, the rear side, the upper side, the lower side, the left side, and the right side of the inner air inlet <NUM>. Therefore, an air intake area of the outer air inlet <NUM> is increased, air can enter the blower <NUM> in multiple directions, air intake efficiency is improved, and wind resistance is reduced. The hood <NUM> includes multiple ribs <NUM> arranged in sequence in a circumferential direction around the first axis. The outer air inlet <NUM> is formed between two adjacent ribs <NUM>. A spacing between adjacent ribs <NUM> is configured to be greater than or equal to <NUM> and less than or equal to <NUM>, thereby increasing an effective air intake area and the air intake efficiency. In this example, a total area of the outer air inlet <NUM> is greater than <NUM><NUM>.

Referring to <FIG>, the outer duct assembly 130a further includes a handle portion <NUM> connected to the front end portion 131a of the outer air inlet <NUM>, where the handle portion <NUM> may be in contact with an upper side of the outer air inlet <NUM>. The handle portion <NUM> may also be spaced apart from the outer air inlet <NUM>, thereby increasing the air intake area. The housing assembly <NUM> further includes an electrical connection portion <NUM> detachably connected to the power supply device, where the power supply device may be a battery pack. The housing assembly <NUM> further includes a bracket <NUM> disposed on a lower side of the outer air inlet <NUM>, where the bracket <NUM> is formed with a support plane. When the battery pack is not mounted to the electrical connection portion <NUM>, a projection of a center of gravity of the entire blower <NUM> on a plane where the support plane is located is located within the support plane so that the blower <NUM> can be stably placed on the plane through the bracket <NUM>. The projection of the center of gravity of the entire blower <NUM> on the plane where the support plane is located is located within a projection of the outer air inlet <NUM> on the plane.

Referring to <FIG>, a ratio of an effective air intake area a1 of the outer air inlet <NUM> to a cross-sectional area a2 of the inner air inlet <NUM> perpendicular to the first axis <NUM> is greater than or equal to <NUM>. A ratio of the effective air intake area a1 of the outer air inlet <NUM> to a cross-sectional area a3 of the inner duct <NUM> in a plane passing through the fan <NUM> and perpendicular to the first axis <NUM> is greater than or equal to <NUM> and less than or equal to <NUM>, thereby increasing an intake air volume and the air intake efficiency of the blower <NUM>. The ratio of the effective air intake area a1 of the outer air inlet <NUM> to the cross-sectional area a3 of the inner duct <NUM> in the plane passing through the fan <NUM> and perpendicular to the first axis <NUM> is greater than or equal to <NUM> or less than or equal to <NUM>, and a distance between the outer air inlet <NUM> and the inner air inlet <NUM> is relatively increased, thereby reducing a wind speed at the outer air inlet <NUM>, reducing the wind resistance, and improving the air intake efficiency.

A distance L1 between the front end portion 131a of the outer air inlet <NUM> and the inner air inlet <NUM> in an axial direction of the first axis <NUM> is greater than or equal to <NUM>, thereby reducing noise generated during operation of the blower <NUM>. Optionally, to improve the air intake efficiency, the distance L1 between the front end portion 131a of the outer air inlet <NUM> and the inner air inlet <NUM> in the axial direction of the first axis is greater than or equal to <NUM> and less than or equal to <NUM>.

For example, as shown in <FIG>, the hood <NUM> includes first ribs 133a, an annular portion 133b, second ribs 133c, and a central portion 133d arranged in sequence from front to rear, where the annular portion 133b connects the first ribs 133a to the second ribs 133c. The annular portion 133b is disposed around the first axis <NUM>, the second ribs 133c and the central portion 133d are disposed on the rear side of the inner air inlet <NUM>, and the central portion 133d is disposed on the first axis <NUM>. The second ribs 133c connect the annular portion 133b to the central portion 133d, and a distance between each of the second ribs 133c and the first axis <NUM> along a connection path between the annular portion 133b and the central portion 133d gradually decreases. That is to say, the second ribs 133a gradually converge from the annular portion 133b to the central portion 133d.

Referring to <FIG> and <FIG>, the electrical connection portion <NUM> includes a slider <NUM>, an elastic element <NUM>, and a positioning groove <NUM>. The slider <NUM> has a first positioning member <NUM> and a second positioning member <NUM>. The elastic element <NUM> abuts against the slider <NUM>. The slider <NUM> is disposed in the positioning groove <NUM>, and the first positioning member <NUM> and the second positioning member <NUM> are configured to abut against the positioning groove <NUM> such that the slider <NUM> can slide in the positioning groove <NUM>. The electrical connection portion <NUM> includes a connection end and a pole piece disposed at the connection end. When the battery pack is connected to the electrical connection portion <NUM>, the battery pack abuts against the connection end and is in contact with the pole piece. The slider <NUM> is partially exposed at the connection end. When the battery pack is not mounted, the slider <NUM> surrounds the pole piece so that a user cannot be in direct contact with the pole piece, thereby preventing the user from being in contact with the pole piece and thus from an electric shock. The elastic element <NUM> is connected to and abuts against the slider <NUM>. When the user inserts the battery pack, the slider <NUM> slides from an outer side of the connection end to an inside of the positioning groove <NUM>, the first positioning member <NUM> and the second positioning member <NUM> support the sliding of the slider <NUM> inside the positioning groove <NUM>, and the slider <NUM> is displaced so that the pole piece is exposed, and the battery pack is electrically connected to the pole piece.

The first positioning member <NUM> and the second positioning member <NUM> are spaced apart from each other in a height direction so that the positioning groove <NUM> may have a certain height, thereby preventing dust from clogging the positioning groove <NUM> and reducing the risk of the slider <NUM> being jammed due to dust. The first positioning member <NUM> and the second positioning member <NUM> are provided, thereby reducing the waggles of the slider <NUM> in the positioning groove <NUM>.

The electrical connection portion <NUM> further includes a lock <NUM> and a release button <NUM>. When the battery pack is connected to the electrical connection portion <NUM>, the lock <NUM> abuts against the front end portion 131a of the slider <NUM>, thereby restraining the elastic element <NUM> from driving the slider <NUM> to move forwards, that is, preventing the slider <NUM> from moving to an outside of the positioning groove <NUM>. A second elastic member <NUM> is connected to the lock <NUM>. When the user toggles the release button <NUM> to compress the second elastic member <NUM>, the lock <NUM> is driven to be displaced, the movement of the slider <NUM> is no longer limited, and the elastic element pushes the slider <NUM> to drive the battery pack to be pulled out from the electrical connection portion <NUM>.

In a working process of the blower <NUM>, the fan <NUM> rotates at a high speed and tends to generate static electricity. Not only does the static electricity easily break down electronic elements of the blower <NUM>, causing damage to the blower <NUM>, but also the static electricity easily causes an electrical spark to strike the user. To reduce the static electricity generated by the fan <NUM>, the number of fan blades needs to be reduced. However, if the number of fan blades is directly reduced, the volume of air generated by the fan <NUM> is insufficient, reducing the performance of the blower <NUM>. Optionally, referring to <FIG>, <FIG>, the fan <NUM> includes fan blades <NUM>, where an outer diameter L2 of the fan blades <NUM> is configured to be greater than <NUM> and less than <NUM> and a minimum distance between two fan blades <NUM> is configured to be greater than or equal to <NUM> and less than or equal to <NUM>. If the distance between fan blades <NUM> is too short, the static electricity generated during the rotation of the fan is increased due to friction of the airflow against the fan blades; and if the distance between the fan blades <NUM> is too long, the volume of air generated by the fan is reduced. An inlet angle α1 of each of the fan blades is configured to be greater than or equal to <NUM>° and less than or equal to <NUM>°. The inlet angle of the fan blade <NUM> refers to an included angle between a tangent line of a front section of a root 122a of the fan blade <NUM> and an axis of the fan <NUM> (where the front section of the root 122a of the fan blade <NUM> refers to a part of the root 122a of the fan blade <NUM> which cuts air relatively first).

The number of the fan blades <NUM> is configured to be greater than or equal to <NUM> and less than or equal to <NUM>. A twist angle α2 of the fan blade <NUM> is configured to be greater than or equal to <NUM>° and less than or equal to <NUM>°. It is found that if the twist angle of the fan blade <NUM> is too large, a wind force generated in the axial direction is relatively small, and if the twist angle of the fan blade <NUM> is too small, the airflow is dispersed in a radial direction of the fan blade <NUM> so that it is necessary to set an appropriate twist angle of the fan blade <NUM> so as to increase the air output of the fan. A diameter L3 of a hub 120a of the fan <NUM> is configured to be greater than or equal to <NUM> and less than or equal to <NUM>, and a length L4 of the root 122a of the fan blade <NUM> is configured to be greater than or equal to <NUM> and less than or equal to <NUM>. A length L5 of an edge of the fan blade <NUM> is configured to be greater than or equal to <NUM> and less than or equal to <NUM>. Compared with the conventional fan <NUM>, the fan <NUM> provided in this example can reduce an air cutting frequency at the same rotational speed and reduce the noise generated by the rotation of the fan <NUM>. A hub diameter ratio is configured to be greater than or equal to <NUM> and less than or equal to <NUM>, the inlet angle of the fan blade <NUM> is reduced, and a chord length of the root 122a of the fan blade <NUM> is increased so that kinetic energy efficiency of the fan <NUM> can be effectively improved. In this manner, the fan <NUM> can generate an increased volume of air under the same power. The hub diameter ratio is a ratio of the outer diameter L2 of the fan blades <NUM> to the diameter L3 of the hub 120a. Optionally, the outer diameter L2 of the fan blades <NUM> is configured to be greater than <NUM> and less than <NUM> so that the kinetic energy efficiency can be better improved.

The outer diameter of the fan blades <NUM> is configured to be greater than <NUM> and less than <NUM>. On an axial projection of the fan <NUM> on a shaft center of the fan <NUM>, an included angle between a line connecting one of adjacent end points of two adjacent fan blades <NUM> and the shaft center and a line connecting the other one of the adjacent end points of the two adjacent fan blades <NUM> and the shaft center is configured to be greater than or equal to <NUM> degrees and less than or equal to <NUM> degrees. Optionally, the included angle between the line connecting one of the adjacent end points of the two adjacent fan blades <NUM> and the shaft center and the line connecting the other one of the adjacent end points of the two adjacent fan blades <NUM> and the shaft center is configured to be greater than or equal to <NUM> degrees and less than or equal to <NUM> degrees. The inlet angle α1 of the fan blade <NUM> is configured to be greater than or equal to <NUM>° and less than or equal to <NUM>°. The number of the fan blades <NUM> is configured to be greater than or equal to <NUM> and less than or equal to <NUM>. For example, in an example, the number of the fan blades <NUM> is set to <NUM>. The diameter L3 of the hub 120a of the fan <NUM> is configured to be greater than or equal to <NUM> and less than or equal to <NUM>, and the length L4 of the root 122a of the fan blade <NUM> is configured to be greater than or equal to <NUM> and less than or equal to <NUM>. The length L5 of the edge of the fan blade is configured to be greater than or equal to <NUM> and less than or equal to <NUM>. Compared with the conventional fan <NUM>, the fan <NUM> provided in this example can reduce the air cutting frequency at the same rotational speed and reduce the noise generated by the rotation of the fan <NUM>. Optionally, the hub diameter ratio (the ratio of the outer diameter of the fan blades <NUM> to the diameter of the hub 120a) is relatively increased to be greater than or equal to <NUM> and less than or equal to <NUM>, the inlet angle of the fan blade is reduced, and the chord length of the root 122a of the fan blade <NUM> is increased so that the kinetic energy efficiency of the fan <NUM> can be effectively improved. In this manner, the fan <NUM> can generate an increased volume of air under the same power.

Referring to <FIG>, a flow guide cone <NUM> that fixes the motor <NUM> is formed inside the inner duct <NUM>, the motor <NUM> is disposed in the flow guide cone <NUM>, and the diameter of the hub of the fan <NUM> and a diameter of an end surface of the flow guide cone <NUM> are consistent or differ by no more than <NUM>% of the diameter of the hub of the fan <NUM> in the axial direction of the first axis <NUM> so that a projection of the hub of the fan <NUM> and a projection of the flow guide cone <NUM> basically overlap in the axial direction of the first axis <NUM>, and no gap exists between the hub of the fan <NUM> and the flow guide cone <NUM> in a radial direction of the first axis <NUM>.

When the motor <NUM> operates, the fan <NUM> rotates to generate a high-speed airflow, the air pressure near the fan <NUM> is relatively low, and a heat dissipation airflow flows from the front end portion 131a of the flow guide cone <NUM> to the rear end portion 131b of the flow guide cone <NUM>, that is, flows to near the fan <NUM>. The hub of the fan <NUM> and the flow guide cone <NUM> are similar in dimension so that the gap between the hub of the fan <NUM> and the flow guide cone <NUM> is reduced, a smaller volume of air of the airflow generated by the rotation of the fan <NUM> flows to the inside of the flow guide cone <NUM>, and an airflow inside the flow guide cone <NUM> is prevented from being disturbed, thereby effectively improving heat dissipation efficiency of the motor <NUM>.

Referring to <FIG> and <FIG>, the blower <NUM> further includes a control unit <NUM> and an operating assembly <NUM>. The fan <NUM> is driven by the motor <NUM> to rotate, the power supply device <NUM> is used for supplying power to the motor <NUM>, the control unit <NUM> controls the operation of the motor <NUM>, and the operating assembly <NUM> is communicatively connected to the control unit <NUM>. The operating assembly <NUM> includes a trigger <NUM> for the user to control the start and rotational speed of the motor <NUM>. The operating assembly <NUM> further includes a speed regulation knob <NUM> configured to be operable so as to perform a first action and a second action. When the speed regulation knob <NUM> is operated so as to perform the first action, the speed regulation knob <NUM> sends an electrical signal to the operating assembly <NUM> so as to adjust and lock the rotational speed of the motor <NUM>. When the second action is performed on the speed regulation knob <NUM>, the speed regulation knob <NUM> sends an electrical signal to the operating assembly <NUM> to lock the fan <NUM> for rotation in a maximum gear. The blower <NUM> further includes a control circuit through which the power supply device <NUM>, the control unit <NUM>, and the operating assembly <NUM> are electrically connected.

The first action is to rotate the speed regulation knob <NUM> along a first direction or a second direction, and the second action is to press the speed regulation knob <NUM>. The inner duct <NUM> is used for supporting the motor <NUM>. The trigger <NUM> is disposed on an upper side of the handle portion <NUM>, and the speed regulation knob <NUM> is disposed on a lower side of the handle portion <NUM> so that when holding the handle portion <NUM>, the user can touch and control the trigger <NUM> and the speed regulation knob <NUM> at the same time, press the trigger <NUM>, and perform the first action and the second action on the speed regulation knob <NUM>. That is, when holding the handle portion <NUM>, the user can press the trigger <NUM> and press the speed regulation knob <NUM> at the same time, or press the trigger <NUM> and rotate the speed regulation knob <NUM> at the same time, or press the trigger <NUM> and press and rotate the speed regulation knob <NUM> at the same time.

Optionally, when the first action is performed on the speed regulation knob <NUM>, the speed regulation knob <NUM> sends a position signal to the control unit <NUM> so as to adjust and lock the rotational speed of the motor <NUM>.

The control unit <NUM> is configured to be an integrated printed circuit board (PCB). When the trigger <NUM> is pressed by the user to be displaced, a first type of signal is sent to the control unit <NUM>, and the control unit <NUM> controls the rotational speed of the motor <NUM> according to information of the first type of signal. Optionally, a resistance value of the control circuit is changed by the displaced trigger <NUM>, so as to send a corresponding voltage signal to the control unit <NUM>, adjust a duty cycle, and thus control the rotational speed of the motor <NUM>. In this case, the first type of signal is the voltage signal. The control unit <NUM> is configured to control, when receiving only the first type of signal, the motor <NUM> to be turned on. Optionally, when the voltage signal reaches a preset value, the control unit <NUM> controls the motor <NUM> to be turned on. When the trigger <NUM> is no longer pressed, the control unit <NUM> controls, according to a change of the first type of signal, the motor <NUM> to stop rotating.

When the speed regulation knob <NUM> is operated so as to perform the first action, that is, the speed regulation knob <NUM> is rotated, a second type of signal is sent to the control unit <NUM>, and the control unit <NUM> locks a minimum rotational speed of the motor <NUM> according to the second type of signal. Optionally, the second type of signal is a phase signal. When the speed regulation knob <NUM> is rotated, a varying phase signal is outputted, and the control unit <NUM> adjusts the duty cycle of the control circuit according to a change of the phase signal so that a speed regulation process is smoother and more reliable.

After the user locks a minimum rotational speed of the fan <NUM> through the speed regulation knob <NUM>, when the user presses the trigger <NUM>, the control unit <NUM> still increases the rotational speed of the fan <NUM> when receiving the first type of signal; after the user releases the trigger <NUM>, limited by a rotational speed signal outputted by the speed regulation knob <NUM>, the rotational speed of the fan <NUM> may be reduced to the minimum rotational speed locked through the speed regulation knob <NUM>. When the speed regulation knob <NUM> is rotated to a certain position, the rotational speed of the fan <NUM> is not lower than a rotational speed corresponding to the position.

Optionally, the speed regulation knob <NUM> is configured such that when the speed regulation knob <NUM> is rotated along the first direction, the control unit <NUM> increases the locked minimum rotational speed of the motor <NUM>. That is, when the speed regulation knob <NUM> is rotated by <NUM> degrees along the first direction, the control unit <NUM> controls the locked minimum rotational speed of the motor <NUM> to be a first rotational speed. When the speed regulation knob <NUM> is rotated by <NUM> degrees, the control unit <NUM> controls the locked minimum rotational speed of the motor <NUM> to be a second rotational speed, where the second rotational speed is greater than the first rotational speed. When the locked minimum rotational speed of the motor <NUM> is the first rotational speed, the control unit <NUM> may control, according to the first type of signal outputted by the trigger <NUM>, the motor <NUM> to rotate at a rotational speed greater than the first rotational speed. When a speed corresponding to a position of the trigger <NUM> is less than the first rotational speed, the control unit <NUM> controls the motor <NUM> to operate at the first rotational speed.

The speed regulation knob <NUM> has a rotational position corresponding to a locked maximum speed, that is, when the speed regulation knob <NUM> is rotated in the first direction to or beyond a certain angle, the control unit <NUM> receives the second type of signal and controls the locked minimum rotational speed of the motor <NUM> to have the highest value. At this time, when the speed regulation knob <NUM> at the rotational position continues to be rotated in the first direction, the control unit <NUM> no longer increases the locked minimum rotational speed of the motor <NUM>. After the speed regulation knob <NUM> is rotated in the first direction to a certain angle, when the speed regulation knob <NUM> is operated and rotated in the second direction opposite to the first direction, the second type of signal is sent to the control unit <NUM>, and the control unit <NUM> controls, according to the second type of signal, the locked minimum rotational speed of the motor <NUM> to decrease. When the speed regulation knob <NUM> continues to be rotated in the second direction, the locked minimum rotational speed of the motor <NUM> may be reduced to zero.

The second type of signal outputted by the speed regulation knob <NUM> includes a first pulse signal and a second pulse signal, and the control unit <NUM> determines a rotational direction of the speed regulation knob <NUM> by identifying a relative position of the first pulse signal and the second pulse signal, thereby identifying a speed-up command or a speed-down command of the user. The control unit <NUM> identifies a rotational angle of the speed regulation knob <NUM> by identifying a phase difference between the first pulse signal and the second pulse signal, thereby correspondingly adjusting the locked minimum rotational speed of the motor <NUM>.

A sensing element is disposed below the speed regulation knob <NUM>. When the speed regulation knob <NUM> is operated so as to perform the second action, that is, the speed regulation knob <NUM> is pressed, the sensing element senses the action on the speed regulation knob <NUM> and sends a third type of signal to the control unit <NUM>. When receiving the third type of signal, the control unit <NUM> controls the motor <NUM> to operate at a set maximum rotational speed. When the motor <NUM> operates at the maximum rotational speed, the fan <NUM> is driven at the maximum rotational speed to rotate, and the control unit <NUM> locks the fan <NUM> for rotation in the maximum gear. Optionally, a maximum value of the locked minimum rotational speed of the motor <NUM> is configured to be less than the maximum rotational speed of the motor <NUM>. That is, when the user operates the speed regulation knob <NUM> to perform the second action only, the motor <NUM> can be driven to operate at the maximum rotational speed to which the rotational speed of the motor <NUM> cannot be regulated by rotating the speed regulation knob <NUM>. When the speed regulation knob <NUM> is operated so as to perform the second action, the control unit <NUM> receives the third type of signal and locks the motor <NUM> to the maximum rotational speed. At this time, the rotation of the motor <NUM> cannot be stopped even if the trigger <NUM> is released.

In an example of the present invention, the operating assembly <NUM> includes the trigger <NUM> and the speed regulation knob <NUM>, where the trigger <NUM> is configured such that when the trigger <NUM> is pressed, the control unit <NUM> controls the motor <NUM> to start, and a displacement of the trigger <NUM> pressed is proportional to the rotational speed. When the speed regulation knob <NUM> is not operated, if the trigger <NUM> is released, the control unit <NUM> controls the motor <NUM> to stop rotating. The specific control principle is similar to that of the preceding examples and is not described in detail here.

The speed regulation knob <NUM> is configured such that the speed regulation knob <NUM> is operated so as to lock the rotational speed currently adjusted to through the trigger <NUM>. When the user presses the trigger <NUM> to cause the motor <NUM> to output at the first rotational speed, the speed regulation knob <NUM> is operated to rotate in the first direction by an angle, so as to lock the rotational speed of the motor <NUM>, where the angle may be one or two units of rotation of the speed regulation knob <NUM>. For example, one unit of rotation of the speed regulation knob <NUM> is <NUM> degrees by which the speed regulation knob <NUM> is rotated. When the user presses the trigger <NUM> to control the motor <NUM> to output at the first rotational speed and then rotates the speed regulation knob <NUM> in the first direction by a preset angle, the speed regulation knob <NUM> generates the second type of signal for the control unit <NUM>, and the control unit <NUM> controls, according to the second type of signal, the rotational speed of the motor <NUM> to be maintained at the first rotational speed. After the rotational speed of the motor <NUM> is locked by rotating the speed regulation knob <NUM>, the trigger <NUM> is released, and the control unit <NUM> controls the motor <NUM> to still rotate at the first rotational speed. After the rotational speed of the motor <NUM> is locked by rotating the speed regulation knob <NUM>, the speed regulation knob <NUM> is rotated along the first direction such that the speed regulation knob sends the second type of signal to the control unit <NUM>, and the control unit <NUM> adjusts the duty cycle to adjust the rotational speed of the motor <NUM>. In this manner, the motor <NUM> can be adjusted to a preset maximum value of the locked rotational speed. An algorithm is provided in the control unit <NUM> such that when the rotational speed of the motor <NUM> reaches the preset maximum value, the rotational speed of the motor <NUM> is no longer increased even when the speed regulation knob <NUM> continues to be rotated along the first direction. At this time, when rotated along the second direction, the speed regulation knob <NUM> generates the second type of signal and sends the second type of signal to the control unit <NUM>, and the control unit <NUM> controls, according to information of the second type of signal, the motor <NUM> to correspondingly reduce the speed according to a rotational angle of the speed regulation knob <NUM> in the second direction until the speed regulation knob <NUM> continues to be rotated in the second direction. In this manner, the speed of the motor <NUM> is reduced to zero.

When the speed regulation knob <NUM> is pressed, the third type of signal is sent to the control unit <NUM>, and the control unit <NUM> adjusts the motor <NUM> to increase the rotational speed so that the fan is at the set maximum rotational speed that is greater than the maximum value of the rotational speed that can be locked by rotating the speed regulation knob <NUM>. At this time, the speed regulation knob <NUM> is rotated in the first direction by at least one unit of rotation such that the speed regulation knob <NUM> sends the second type of signal to the control unit <NUM> and the control unit <NUM> locks the motor <NUM> at the maximum rotational speed. The control unit <NUM> is configured to control the motor <NUM> to be disengaged from a locked state and end the maximum rotational speed of the motor <NUM> when receiving only the second type of signal generated by the speed regulation knob <NUM> when rotated in the second direction.

Claim 1:
A blower, comprising:
a motor (<NUM>);
a fan (<NUM>) driven by the motor (<NUM>) to rotate about a first axis (<NUM>);
a power supply device (<NUM>) for supplying power to the motor (<NUM>); and
a housing assembly (<NUM>) accommodating the motor (<NUM>) and comprising:
an inner duct (<NUM>) formed with an inner air inlet (<NUM>); and
an outer duct assembly (130a) surrounding the inner duct (<NUM>);
wherein the outer duct assembly (130a) comprises an outer duct (<NUM>) and a hood (<NUM>), wherein the outer duct (<NUM>) is disposed on a front side of the hood (<NUM>), an outer air outlet (<NUM>) is formed at an end of the outer duct (<NUM>) facing away from the hood (<NUM>), an outer air inlet (<NUM>) is formed on the hood (<NUM>) and has a front end portion (131a) and a rear end portion (131b) along a direction of the first axis (<NUM>), characterized in that, the inner air inlet (<NUM>) is disposed between the front end portion (131a) and the rear end portion (131b) along the direction of the first axis (<NUM>).