Milling machine main shaft fan

Abstract

The fan includes a fan blade having a radially inner end and a radially outer end, and an attachment sleeve having a radially inner surface and a radially outer surface. The radially inner surface includes a tool contact surface and the radially outer surface engages a radially inner end of the fan blade. The powder discharging fan further comprises an outer sleeve connected with the radial outer ends of the fan blades, and the outer sleeve forms a ring.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of machining, and more particularly, to a milling machine having a dust fan for removing dust. BACKGROUND

[0002] Milling machines are widely used in various industries for shaping and cutting materials such as metals, plastics, and composites. These machines generally use a rotating cutting tool, known as a milling cutter, to remove material from a workpiece. The workpiece is securely fixed on a table. The table can be moved relative to the milling cutter, or the milling cutter can be moved relative to the table, in order to enable precise positioning and feeding of the workpiece into the cutting tool. For some milling machines, the movement of the milling cutter relative to the workpiece can be manually controlled by an operator or controlled through computer numerical control ("CNC").

[0003] Depending on the type of workpiece being machined, a cutting fluid can be applied to the milling cutter and the workpiece to reduce friction and heat generated during the machining process. Additionally, for some workpiece materials, a vacuum source can be used to collect dust formed by the milling cutter. SUMMARY

[0004] A dust evacuation fan is disclosed herein. The dust evacuation fan includes fan blades having a radially inner end and a radially outer end, and an attachment sleeve having a radially inner surface and a radially outer surface. The radially inner surface includes a tool contact surface, and the radially outer surface engages the radially inner end of the fan blades. The dust evacuation fan further includes an outer sleeve tube connecting the radially outer ends of the fan blades, the outer sleeve tube forming a ring.

[0005] In one aspect of the disclosure, the outer sleeve tube includes a conical shape.

[0006] In one aspect of the disclosure, the radially inner end of each fan blade is clocked relative to the corresponding one of the radially outer ends of the fan blades.

[0007] In one aspect of the disclosure, the plurality of fan blades includes a radially inner chord length adjacent the radially inner end of each fan blade, the radially inner chord length being less than a radially outer chord length adjacent the radially outer end of each fan blade.

[0008] In one aspect of the disclosure, the attachment sleeve extends a first axial length relative to an axis of rotation of the dust evacuation fan, and the outer sleeve tube extends a second axial length relative to the axis of rotation of the dust evacuation fan, wherein the second axial length is greater than the first axial length.

[0009] In one aspect of the disclosure, the attachment sleeve is at least partially axially offset from the outer sleeve tube relative to an axis of rotation of the dust evacuation fan.

[0010] In one aspect of the disclosure, the attachment sleeve is at least partially offset from the outer sleeve tube by at least 50% of an axial length of the attachment sleeve.

[0011] In one aspect of the disclosure, the radially inner end of each fan blade is axially outwardly offset from the axial end of the outer sleeve relative to the rotational axis of the powder exhaust fan.

[0012] In one aspect of the disclosure, the radially outer end of each fan blade is axially outwardly offset from the axial end of the attachment sleeve relative to the rotational axis of the powder exhaust fan.

[0013] In one aspect of the disclosure, the attachment sleeve includes a fastener opening for receiving a fastener, and the fastener opening is positioned axially outwardly from the axial end of the outer sleeve relative to the rotational axis of the powder exhaust fan.

[0014] A milling machine is disclosed herein. The milling machine includes a drive motor engaged with a spindle drive, a cutter attached to the spindle and configured to rotate with the spindle, and a powder exhaust fan attached to the cutter and configured to rotate with the cutter. The powder exhaust fan includes fan blades having radially inner ends and radially outer ends, and an attachment sleeve having a radially inner surface and a radially outer surface. The radially inner surface includes a cutter contact surface, and the radially outer surface engages the radially inner ends of the fan blades. The powder exhaust fan further includes an outer sleeve connecting the radially outer ends of the fan blades, the outer sleeve forming a ring.

[0015] In one aspect of the disclosure, the outer sleeve includes a conical shape.

[0016] In one aspect of the disclosure, the radially inner end of each fan blade is clocked relative to the corresponding one of the radially outer ends of the fan blades.

[0017] In one aspect of the disclosure, the fan blades include a radially inner chord length adjacent the radially inner end of each fan blade, the radially inner chord length being less than a radially chord length adjacent the radially outer end of each fan blade.

[0018] In one aspect of the disclosure, the attachment sleeve extends a first axial length relative to the rotational axis of the powder exhaust fan, and the outer sleeve extends a second axial length relative to the rotational axis of the powder exhaust fan, wherein the second axial length is greater than the first axial length.

[0019] In one aspect of the disclosure, the attachment sleeve is partially axially offset from the outer sleeve relative to the rotational axis of the powder exhaust fan.

[0020] In one aspect of the disclosure, the attachment sleeve includes a fastener opening for receiving a fastener, and the fastener opening is positioned axially outwardly from the axial end of the outer sleeve relative to the rotational axis of the powder exhaust fan.

[0021] A method of operating a milling machine to form a workpiece is disclosed herein. The method includes receiving, using a controller, a tool path representative of a part, and instructing a tool to engage the workpiece and selectively remove material from the workpiece while following the tool path. The method further includes generating, using a chip evacuation fan, an air flow in an intersection region of the tool and the workpiece to clear debris from the tool path by selecting a rotational speed for the tool based on a material of the workpiece and a feed rate of the tool. The chip evacuation fan includes a fan blade and an attachment sleeve having a radially inner surface and a radially outer surface, wherein the radially inner surface has a tool attachment surface in direct contact with the tool, and a radially inner end of the fan blade extends radially outward from the radially outer surface of the attachment sleeve. The chip evacuation fan further includes an outer sleeve connected to a distal end of the fan blade forming a ring.

[0022] The present invention provides the following technical solutions:

[0023] 1. A chip evacuation fan, comprising:

[0024] a plurality of fan blades each having a radially inner end and a radially outer end;

[0025] an attachment sleeve having a radially inner surface and a radially outer surface, wherein the radially inner surface includes a tool contact surface and the radially outer surface is engaged with the radially inner ends of the plurality of fan blades; and

[0026] an outer sleeve tube connected to the radially outer ends of the plurality of fan blades, wherein the outer sleeve tube forms a ring.

[0027] 2. The chip evacuation fan of solution 1, wherein the outer sleeve tube includes a conical shape.

[0028] 3. The chip evacuation fan of solution 1, wherein the radially inner end of each of the plurality of fan blades is clocked relative to a corresponding one of the radially outer ends of the plurality of fan blades.

[0029] 4. The chip evacuation fan of solution 1, wherein the plurality of fan blades includes a radially inner chord length proximate the radially inner end of each of the plurality of fan blades that is less than a radially outer chord length proximate the radially outer end of each of the plurality of fan blades.

[0030] 5. The chip evacuation fan of solution 1, wherein the attachment sleeve extends a first axial length relative to an axis of rotation of the chip evacuation fan and the outer sleeve tube extends a second axial length relative to the axis of rotation of the chip evacuation fan, wherein the second axial length is greater than the first axial length.

[0031] 6. The chip evacuation fan of solution 1, wherein the attachment sleeve is partially axially offset relative to the outer sleeve tube with respect to the axis of rotation of the chip evacuation fan.

[0032] 7. The dust exhaust fan of Scheme 6, wherein the attachment sleeve is at least partially offset from the outer sleeve by at least 50% of an axial length of the attachment sleeve.

[0033] 8. The dust exhaust fan of Scheme 1, wherein a radially inner end of each of the plurality of fan blades is offset axially from an axial end of the outer sleeve relative to the axis of rotation of the dust exhaust fan.

[0034] 9. The dust exhaust fan of Scheme 1, wherein a radially outer end of each of the plurality of fan blades is offset axially from an axial end of the attachment sleeve relative to the axis of rotation of the dust exhaust fan.

[0035] 10. The dust exhaust fan of Scheme 1, wherein the attachment sleeve includes a fastener opening for receiving a fastener, and the fastener opening is positioned axially outward from an axial end of the outer sleeve relative to the axis of rotation of the dust exhaust fan.

[0036] 11. The dust exhaust fan of Scheme 1, wherein

[0037] the outer sleeve comprises a conical shape;

[0038] a radially inner end of each of the plurality of fan blades is clock-wise relative to a corresponding one of the radially outer ends of the plurality of fan blades;

[0039] the plurality of fan blades includes a radially inner chord length adjacent the radially inner end of each of the plurality of fan blades, the radially inner chord length being less than a radially chord length adjacent the radially outer end of each of the plurality of fan blades;

[0040] wherein the attachment sleeve extends a first axial length relative to the axis of rotation of the dust exhaust fan, and the outer sleeve extends a second axial length relative to the axis of rotation of the dust exhaust fan, wherein the second axial length is greater than the first axial length; and

[0041] the attachment sleeve is at least partially axially offset from the outer sleeve relative to the axis of rotation of the dust exhaust fan.

[0042] 12. A milling machine comprising:

[0043] a drive motor engaged with the spindle drive;

[0044] a cutter attached to the spindle and configured to rotate with the spindle;

[0045] a dust exhaust fan attached to the cutter and configured to rotate with the cutter, the dust exhaust fan comprising:

[0046] a plurality of fan blades, each fan blade having a radially inner end and a radially outer end;

[0047] an attachment sleeve having a radially inner surface and a radially outer surface, wherein

[0048] the radially inner surface comprises a cutter contact surface and the radially outer surface engages a radially inner end of a plurality of fan blades; and

[0049] an outer sleeve tube connecting radially outer ends of the plurality of fan blades, wherein the outer sleeve tube forms a ring.

[0050] 13. The mill according to paragraph 12, wherein the outer sleeve tube comprises a conical shape.

[0051] 14. The mill according to paragraph 12, wherein the radially inner end of each of the plurality of fan blades is clock-wise relative to a corresponding one of the radially outer ends of the plurality of fan blades.

[0052] 15. The mill according to paragraph 12, wherein the plurality of fan blades comprises a radially inner chord length adjacent to the radially inner end of each of the plurality of fan blades that is less than a radially chord length adjacent to the radially outer end of each of the plurality of fan blades.

[0053] 16. The mill according to paragraph 12, wherein the attachment sleeve extends a first axial length relative to an axis of rotation of the dust exhaust fan and the outer sleeve tube extends a second axial length relative to the axis of rotation of the dust exhaust fan, wherein the second axial length is greater than the first axial length.

[0054] 17. The mill according to paragraph 12, wherein the attachment sleeve is partially axially offset from the outer sleeve tube relative to the axis of rotation of the dust exhaust fan.

[0055] 18. The mill according to paragraph 12, wherein the attachment sleeve comprises a fastener opening for receiving a fastener, and the fastener opening is positioned axially outward from an axial end of the outer sleeve tube relative to the axis of rotation of the dust exhaust fan.

[0056] 19. The mill according to paragraph 12, wherein

[0057] the outer sleeve tube comprises a conical shape;

[0058] the radially inner end of each of the plurality of fan blades is clock-wise relative to a corresponding one of the radially outer ends of the plurality of fan blades;

[0059] the plurality of fan blades comprises a radially inner chord length adjacent to the radially inner end of each of the plurality of fan blades that is less than a radially chord length adjacent to the radially outer end of each of the plurality of fan blades;

[0060] wherein the attachment sleeve extends a first axial length relative to an axis of rotation of the powder exhaust fan, and the outer sleeve extends a second axial length relative to the axis of rotation of the powder exhaust fan, wherein the second axial length is greater than the first axial length; and

[0061] The attachment sleeve is partially axially offset from the outer sleeve relative to the axis of rotation of the powder exhaust fan.

[0062] 20. A method of operating a milling machine to form a workpiece, the method comprising:

[0063] receiving, with a controller, a tool path representing a part;

[0064] indicating a tool to engage the workpiece and selectively remove material from the workpiece while following the tool path;

[0065] generating an air flow with a powder exhaust fan in an intersection region of the tool and the workpiece to clear debris from the tool path by selecting a rotational speed for the tool according to a material of the workpiece and a feed rate of the tool, wherein the powder exhaust fan comprises:

[0066] a plurality of fan blades;

[0067] an attachment sleeve having a radially inner surface and a radially outer surface, wherein,

[0068] the radially inner surface includes a tool attachment surface in direct contact with the tool, and radially inner ends of the plurality of fan blades extend radially outward from the radially outer surface of the attachment sleeve; and

[0069] an outer sleeve connecting distal ends of the plurality of fan blades, wherein the outer sleeve forms a ring. BRIEF DESCRIPTION OF DRAWINGS

[0070] Figure 1 is a schematic diagram of an example milling machine having a powder exhaust fan.

[0071] Figure 2 is a top view schematic of the powder exhaust fan of Figure 1

[0072] Figure 3 is a side view schematic of the powder exhaust fan of Figure 1

[0073] Figure 4 is a top perspective cutaway schematic of the powder exhaust fan of Figure 1

[0074] Figure 5 is a bottom perspective cutaway schematic of the powder exhaust fan of Figure 1

[0075] Figure 6 is a method of operating the milling machine of Figure 1 ​​​​a flowchart of an example method of a milling machine.

[0076] The present disclosure can be modified or implemented in alternative forms, representative embodiments of which are shown in the drawings and described in detail below. The inventive aspects of the present disclosure are not limited to the disclosed embodiments. Rather, the present disclosure is intended to cover alternatives that fall within the scope of the present disclosure as defined by the appended claims. DETAILED DESCRIPTION

[0077] One of ordinary skill in the art will recognize that terms such as "above," "below," "up," "down," "top," "bottom," "left," "right," and the like are used to describe the disclosure as oriented in the drawings, and are not meant to limit the scope of the disclosure as defined by the appended claims. Furthermore, the present teachings can be described in terms of functional and / or logical block components and / or various processing steps. It should be recognized that such block components can be comprised of a number of hardware, software, and / or firmware components.

[0078] Referring to the drawings, wherein like numerals represent like components throughout the several views, Figure 1 A schematic view of a milling machine 20 is shown. The milling machine 20 allows a milling tool (e.g., tool 38) to move relative to a workpiece 39 on a workpiece holder 41. In the example shown, the workpiece 39 is composed of a clay-based material. One characteristic of milling a clay-based material is that the debris formed during the milling process can accumulate along the tool path of the tool 38 or embed into the finished surface of the workpiece 39. This affects the surface quality of the workpiece 39 and can cause tool wear. In addition, the size of the accumulated particles and the volume of the particles can vary depending on the feed rate of the tool 38. Furthermore, the present disclosure is applicable to milling a workpiece composed of materials other than clay, such as a workpiece or metal.

[0079] In the illustrated example, the milling machine 20 includes a frame 21 that supports the milling machine 20 on a floor surface. The milling machine 20 is configured to allow the tool 38 to move along an x-axis, a y-axis, and a z-axis. A vertical column 22 includes a motor 24 that moves a horizontal crossbar 26 along the z-axis in a track extending along the vertical column 22. The horizontal crossbar 26 includes a motor 28 that moves a second crossbar 30 along the x-axis in a track extending along the horizontal crossbar 26. In addition, the second horizontal crossbar 30 includes a motor 32 that moves the tool 38 along the y-axis in a track extending along the second horizontal crossbar 30. This configuration of the milling machine 20 is commonly referred to as a three-axis milling machine, i.e., x-axis, y-axis, and z-axis. However, the milling machine 20 can be configured to move the workpiece 39 along additional axes by manipulating the workpiece holder 41, such as along at least one of a first rotational axis Rl that passes vertically through the workpiece 39 or a second rotational axis R2 that tilts the workpiece 39, as shown in FIG. 2. In the example shown, the workpiece holder 41 is configured to rotate about the first rotational axis Rl by a motor 34 that is coupled to the workpiece holder 41. In addition, the workpiece holder 41 is configured to tilt about the second rotational axis R2 by a motor 36 that is coupled to the workpiece holder 41. In the example shown, the motors 24, 28, 32, 34, and 36 are coupled to a controller 40 that is configured to control the movement of the tool 38 and the workpiece 39. Figure 1These additional axes will allow the milling machine 20 to operate as a five-axis milling machine. In addition, the present disclosure is applicable to other configurations of milling machines.

[0080] The milling machine 20 includes a drive motor 34 that rotates the tool 38 at a predetermined rotational speed. The tool 38 is attached to the milling machine by a chuck 36, however, other types of fixtures can be used to attach the tool 38 to the drive motor 34. A dust evacuation fan 40 is directly attached to the tool 38 such that the dust evacuation fan 40 rotates at the same rotational speed as the tool 38.

[0081] In addition, the milling machine 20 can be operated manually or by using an electronic controller 70. The electronic controller 70 can be configured to communicate with the motors 24, 28, 32, and 34 to control the movement of the tool 38 along the x, y, and z axes. The electronic controller 70 can also be referred to as a control module, control unit, controller, computer, etc. The electronic controller 70 can include a computer and / or processor 72 and include software, hardware, memory, algorithms, etc. for managing and controlling the milling machine 20. Thus, the methods described below and generally represented in Figure 2 can be implemented as programs or algorithms that are operable, in part, on the electronic controller 70. It should be understood that the electronic controller 70 can include devices capable of performing the required tasks to control the operation of the milling machine 20.

[0082] The electronic controller 70 can be implemented as one or more digital computers or mainframes, each having one or more processors 72, read only memory (ROM), random access memory (RAM), electrically programmable read only memory (EPROM), optical drives, magnetic drives, etc., high speed clocks, analog to digital (A / D) circuits, digital to analog (D / A) circuits, input / output (I / O) circuits, I / O devices and communication interfaces, as well as signal conditioning and buffering electronics. Computer readable memory can include non-transitory / tangible media involved with providing data or computer-readable instructions. The memory can be non-volatile or volatile. Non-volatile media can include, for example, optical or magnetic disks and other persistent memory. Example volatile media can include dynamic random access memory (DRAM), which can form a main memory. Other examples of embodiments for memory include floppy disks, hard disks, magnetic tape, or other magnetic media, CD-ROMs, DVDs, and / or other optical media, and other possible storage devices and media, such as flash memory.

[0083] The electronic controller 70 includes tangible, non-transitory memory 74 having computer executable instructions recorded thereon, including one or more algorithms for regulating the operation of the milling machine 20. The subject algorithms can specifically include algorithms configured to instruct the milling machine 20 to follow a tool path for the tool 38 to form a final workpiece, as discussed in greater detail below with reference to the method 100.

[0084] like Figures 2-5 As shown, the dust removal fan 40 includes an attachment sleeve 42, a plurality of fan blades 48, and an outer sleeve 50. In the illustrated example, the attachment sleeve 42 is cylindrical and includes a radially inner surface 44 that defines a tool contact surface for directly engaging the tool 38. The attachment sleeve 42 also includes a radially outer surface 46 from which the radially inner ends of the fan blades 48 extend radially outward. The axial end of the attachment sleeve 42 may also include a support 47 provided from the axial end, the support having a radial thickness less than the radial thickness of the central portion of the attachment sleeve 42. In this disclosure, unless otherwise stated, radial or radially, axial or axially, longitudinal or longitudinal are relative to the axis of rotation A of the dust removal fan 40.

[0085] The connecting sleeve 42 also includes a fastener opening 43 for receiving a fastener 45, such as a set screw. The fastener opening 43 is located axially outward from the axial end of the outer sleeve 50 within the connecting sleeve 42 relative to axis A.

[0086] In the example shown, the fan blade 48 extends radially outward from the proximal or radially inner end of the fan blade 48 at the connecting sleeve 42 to the distal or radially outer end of the outer sleeve 50. For example... Figure 2 As shown, the fan blade 48 extends in both radial and circumferential directions, such that the outer radial end of the fan blade 48 is clock-shaped relative to the inner radial end of the fan blade 48.

[0087] In addition, such as Figures 4-5 As shown, the fan blades include a pressure side or concave side 56, which is opposite to the suction side or convex side 58. Furthermore, the chord length between the leading and trailing edges of each fan blade 48 at its radially inner or proximal end is less than the chord length of each fan blade 48 at its radially outer or distal end. The connecting sleeve 42 also includes an axial length less than the axial length of the outer sleeve 50.

[0088] In the example shown, the outer sleeve 50 includes a radially inner surface 52 and a radially outer surface 54. The outer sleeve 50 includes a conical shape that tapers gradually from one end adjacent to the inlet 60 of the dust removal fan 40 to the outlet 62, which draws in air as it rotates, and the outlet 62 expels the air from the dust removal fan 40. Furthermore, as... Figure 2 and Figures 4-5As shown, the upstream end of the attachment sleeve 42 is recessed into the outer sleeve 50 proximate the inlet 60 such that the upstream end of the attachment sleeve 42 and the upstream end of the outer sleeve 50 are at least partially axially offset relative to one another. Further, the downstream end of the attachment sleeve 42 axially protrudes beyond the axial end of the outer sleeve 50 at the outlet 62 such that the downstream end of the attachment sleeve 42 and the downstream end of the outer sleeve 50 are at least partially axially offset relative to one another. In the present disclosure, upstream and downstream are in reference to the direction of air flow through the dust exhaust fan 40 during normal operation, which produces an air flow that flows out of the outlet end 62 and over the cutter 38. Additionally, the radially inner end of the fan blade 48 is at least partially offset in a downstream direction relative to the radially outer end of the fan blade 48.

[0089] Further, the axial length of the attachment sleeve 42 is less than the axial length of the outer sleeve 50. Additionally, the attachment sleeve 42 is at least axially offset from the outer sleeve 50 by at least 50% of the axial length of the attachment sleeve 42 such that more than 50% of the axial length of the attachment sleeve 42 is spaced outwardly from one of the axial ends of the outer sleeve 50. Likewise, the radially inner end of the fan blade 48 is partially axially offset outwardly from one of the axial ends of the outer sleeve 50.

[0090] Figure 6 An example method 100 of operating the milling machine 20 to machine the workpiece 39 into a desired shape is shown. The method 100 begins at block 102 by the electronic controller 70 receiving a cutter path representative of a desired shape to be formed by the workpiece 39. The method then continues to block 104.

[0091] At block 104, the electronic controller 70 instructs the cutter 38 to engage the workpiece 39 and selectively remove material from the workpiece 39 while following the cutter path. In addition to instructing the cutter 38, the electronic controller 70 also selects a rotational speed for the cutter 38 based on at least one of a material type of the workpiece 39 or a feed rate of the cutter 38. This will allow the dust exhaust fan 40 to generate enough force to clear debris from the intersection of the cutter 38 and the workpiece 39. The method 100 then continues to block 106 where the dust exhaust fan 40 generates an air flow that removes debris generated by the cutter 38 as the cutter engages the workpiece 39. One feature of this configuration is that no additional power source is needed to generate the air flow as it is generated directly from the rotation of the cutter.

[0092] The terms “a” and “an” do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. The term “or” means “and / or” unless clearly indicated otherwise. The phrase “in one aspect” means that a particular feature, structure, step, or characteristic described is included in at least one aspect of the disclosure, and can or can not be included in other aspects. Furthermore, it is intended that elements described in association with one aspect can be combined in whole or in part with other aspects as can be desired.

[0093] When an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements can also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

[0094] Unless otherwise defined herein, test standards are the most recent active standard at the time of filing of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0095] Unless otherwise defined herein, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0096] While the foregoing disclosure has been described in reference to illustrative examples, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope thereof. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. Therefore, it is intended that the disclosure not be limited to the particular disclosed embodiments, but will include all embodiments falling within the scope of the disclosure.

Claims

1. A dust removal fan, comprising: Multiple fan blades, each fan blade having a radial inner end and a radial outer end; An attachment sleeve having a radially inner surface and a radially outer surface, wherein the radially inner surface includes a tool contact surface and the radially outer surface engages with the radially inner ends of a plurality of wind turbine blades; as well as An outer sleeve connecting the radially outer ends of multiple wind turbine blades, wherein the outer sleeve forms a ring.

2. The dust removal fan according to claim 1, wherein the outer casing is conical.

3. The dust removal fan according to claim 1, wherein the radial inner end of each of the plurality of fan blades is clock-shaped relative to the corresponding one of the radial outer ends of the plurality of fan blades.

4. The dust removal fan according to claim 1, wherein, The plurality of wind turbine blades include a radial inner chord length of the radial inner end of each of the plurality of wind turbine blades, which is less than the radial chord length of the radial outer end of each of the plurality of wind turbine blades.

5. The dust removal fan according to claim 1, wherein, The attachment sleeve extends a first axial length relative to the rotation axis of the dust removal fan, and the outer sleeve extends a second axial length relative to the rotation axis of the dust removal fan, wherein the second axial length is greater than the first axial length.

6. The dust removal fan according to claim 1, wherein the attached sleeve is partially offset axially from the outer sleeve relative to the rotation axis of the dust removal fan.

7. The dust removal fan according to claim 6, wherein, The attachment sleeve is offset from the outer sleeve at least partially by at least 50% of the axial length of the attachment sleeve.

8. The dust removal fan according to claim 1, wherein, The radial inner end of each of the multiple fan blades is offset axially outward from the axial end of the outer casing relative to the rotation axis of the dust exhaust fan.

9. The dust removal fan according to claim 1, wherein the radially outer end of each of the plurality of fan blades is offset axially outward from the axial end of the attached sleeve relative to the rotation axis of the dust removal fan.

10. The dust removal fan according to claim 1, wherein, The attachment sleeve includes a fastener opening for receiving fasteners, and the fastener opening is axially positioned outward from the axial end of the outer sleeve relative to the rotation axis of the dust exhaust fan.

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