Power tool

Abstract

A power tool is disclosed that includes a housing, a motor within the housing, a rotor within the motor, and a fan assembly. The rotor and fan assembly includes a rotor with a plurality of magnets each having an overlapping portion extending beyond a face of the rotor, and a fan adjacent a face of the rotor. The fan includes a plurality of magnet pockets, and an overlapping portion of each magnet extends into a respective magnet pocket of the plurality of magnet pockets.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to co-pending U.S. Provisional Patent Application No. 63 / 356,742, filed June 29, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This utility model relates to power tools, and more specifically to impact tools. Background Technology

[0004] Impact tools such as impact drills and impact wrenches are typically used to apply intermittent striking rotational force or torque to tool elements or workpieces (such as fasteners) to tighten or loosen fasteners. Utility Model Content

[0005] In one aspect, the present invention provides a power tool comprising a housing, a motor within the housing, a rotor within the motor, and a fan assembly. The rotor and fan assembly includes a rotor with a plurality of magnets and a fan adjacent to the face of the rotor, each magnet having an overlapping portion extending beyond the face of the rotor. The fan includes a plurality of magnet pouches, and the overlapping portion of each magnet extends into the respective magnet pouches of the plurality of magnet pouches.

[0006] On the other hand, the present invention provides a power tool including a housing, a motor supported within the housing, and a fan. The motor includes a stator and a rotor, the rotor including a plurality of permanent magnets, each permanent magnet having an overlapping portion extending beyond the face of the rotor. The fan is coupled to the rotor to rotate with the rotor relative to the stator. The fan includes a disc-shaped base plate, a central hub extending from the disc-shaped base plate, and a plurality of magnet bags extending into the central hub, wherein each magnet bag receives a respective overlapping portion of each permanent magnet.

[0007] In another aspect, the present invention provides a power tool including a housing, a motor supported within the housing, and a fan. The motor includes a stator and a rotor. The rotor includes a plurality of metal layers laminated together, a plurality of magnet bags extending vertically through the plurality of metal layers, and permanent magnets disposed within each of the plurality of magnet bags. Each permanent magnet includes an overlapping portion extending beyond the face of the rotor. The fan is coupled to the rotor to rotate with the rotor relative to the stator. The fan includes a plurality of magnet bags, and the overlapping portion of each permanent magnet extends into one of the magnet bags.

[0008] Other features and aspects of this invention will become apparent from the following detailed description and accompanying drawings. Attached Figure Description

[0009] Figure 1This is a perspective view of an impact tool according to a specific embodiment.

[0010] Figure 2 yes Figure 1 Front view of the impact tool.

[0011] Figure 3 yes Figure 1 Side view of the impact tool.

[0012] Figure 4 It is along Figure 2 The line formed by 4-4 Figure 1 A cross-sectional view of the impact tool.

[0013] Figure 5 It is along Figure 3 The line formed by 5-5 Figure 1 A cross-sectional view of the impact tool.

[0014] Figure 6 It is used for Figure 1 A three-dimensional view of the rotor and fan assembly of the impact tool.

[0015] Figure 7 yes Figure 6 Side view of the rotor and fan assembly.

[0016] Figure 8 yes Figure 6 Cross-sectional view of the rotor and fan assembly.

[0017] Before a detailed discussion of any specific embodiments of this utility model, it should be understood that this utility model is not limited to its application in the construction details and component arrangements described below or shown in the accompanying drawings. This utility model can have other specific embodiments and can be implemented or realized in various ways. Furthermore, it should be understood that the wording and terminology used in this application are for illustrative purposes only and should not be considered limiting. Detailed Implementation

[0018] As described in more detail below, in some aspects, this disclosure provides a power tool including a motor with a rotor and fan assembly. The rotor and fan assembly includes a rotor with a plurality of magnets and a fan adjacent to the rotor. A portion of the magnets is housed within a magnet pocket, which is formed within the fan. Thus, the overall length of the rotor and fan assembly can be reduced compared to a typical motor.

[0019] Reference Figures 1-5 The image shows a power tool, typically labeled 100. As shown, the power tool is a rotary impact tool 100 (i.e., an impact drill). Specifically, the power tool is a battery-powered rotary impact tool 100. Figure 1As shown, the rotary impact tool 100 includes a housing 102, which has a first housing side 104 and a second housing side 106. Figure 1 As shown, shell sides 104 and 106 converge to form interface 108 between shell sides 104 and 106. It should be understood that shell sides 104 and 106 are mating clamshell halves that are attached to each other by a plurality of fasteners 110 (e.g., screws) or otherwise secured to each other. Alternatively, shell sides 104 and 106 may be secured to each other by adhesive, by plastic welding, or by any other suitable means.

[0020] like Figures 3-4 As depicted, housing 102 includes a drive portion 112 defining a drive axis 114. Housing 102 also includes a handle portion 116 extending in a direction substantially perpendicular to the drive axis 114. The drive portion 112 of housing 102 includes components operably coupled to a gear assembly 120. Figure 4 Motor 118. Gear assembly 120 is operatively coupled to drive assembly 122. The illustrated motor 118 is a brushless DC (“BLDC”) motor having a rotor and fan assembly 124, which is partially arranged within a stator 126. Motor 118 further includes an output shaft 130 coupled to and rotating therewith the rotor and fan assembly 124. The following will be combined with... Figures 6-8 A more detailed description is given of the rotor and fan assembly 124.

[0021] like Figure 5 As shown, the gear assembly 120 includes a sun gear 132 disposed on the output shaft 130 of a motor 118. A plurality of planetary gears 134 mesh with the sun gear 132 and are disposed on a gear carrier 136. An outer ring gear 138 surrounds and meshes with the planetary gears 134. The outer ring gear 138 is fixed within the drive portion 112 of the housing 102 and does not rotate. Accordingly, when the sun gear 132 rotates in one direction, the planetary gears 134 rotate in the opposite direction and run around the inner periphery of the outer ring gear 138, thereby causing the gear carrier 136 to rotate at a reduced speed. Thus, the gear assembly 120 provides a reduction in speed from the sun gear 132 to the gear carrier 136 and an increase in torque.

[0022] Reference Figure 4The drive assembly 122 shown includes a camshaft 140, and a gear carrier 136 is formed at the end of the camshaft 140. Accordingly, rotation of the output shaft 130 causes a planetary gear 134 to rotate, which travels along the inner circumference of an outer ring gear 138 to rotate the camshaft 140. The gear assembly 120 thus provides a reduction in speed and an increase in torque from the output shaft 130 to the camshaft 140. The output shaft 130 is rotatably supported by a first bearing or front bearing 142 and a second bearing or rear bearing 144, the first bearing or front bearing 142 being located within the camshaft 140.

[0023] The drive assembly 122 of the impact tool 100 further includes an anvil 150 extending from the gearbox 22, the anvil 150 having a drill retainer 152 to which tool elements (e.g., screwdriver heads, socket heads, etc., not shown) are coupled to for working on a workpiece (e.g., a fastener). The anvil 150 is rotatably supported by a bearing 166, which is fixed within the front portion of the housing 102. The drive assembly 122 is configured to convert the continuous rotational force or torque provided by the motor 118 and the gear assembly 120 into intermittent application of a striking rotational force or torque to the anvil 150 when the reaction torque on the anvil 150 (e.g., due to the engagement between the tool element and the fastener being worked) exceeds a certain threshold. In the illustrated embodiment of the impact tool 100, the drive assembly 120 includes a camshaft 140, a hammer 154 supported on the camshaft 140 and axially slidable relative to the camshaft 140, and the anvil 150.

[0024] Continue to refer to Figure 4 The drive assembly 122 further includes a mechanism that directs the hammer 154 toward the front of the impact tool 100 (i.e. toward...). Figure 4 The spring 156 (right side of the image) is biased. In other words, the spring 156 biases the hammer 154 axially toward the anvil 150 along axis 114. Thrust bearing 158 and thrust washer 160 are positioned between the spring 156 and the hammer 154. When the lug on the hammer 154 engages with the corresponding anvil lug and the rotation of the hammer 154 stops briefly, the thrust bearing 158 and thrust washer 160 allow the spring 156 and camshaft 140 to continue rotating relative to the hammer 154 after each impact strike.

[0025] The camshaft 140 further includes a cam groove 162 in which a corresponding cam ball 164 is received. The cam ball 164 is driven to engage with the hammer 154, and as the hammer lug engages with the anvil lug and the camshaft 140 continues to rotate, the movement of the cam ball 164 within the cam groove 162 allows the hammer 154 to move along the relative axial direction of the camshaft 140.

[0026] Figures 1-4The handle portion 116 of the impact tool 100 is further shown, including a grip 170. Additionally, the handle portion 116 includes a battery socket 172 configured to receive a removable battery pack to power a motor 118. A circuit board 174 is disposed within the handle portion 116 and includes electronics for controlling the operation of the impact tool 100. Figure 4 The handle portion 116 also includes a trigger 176 actuated to selectively energize the motor 118. Figure 2 and Figure 3 The impact tool 100 is further shown to include a direction selector button 178 extending laterally through the housing 102. The direction selector button 178 allows the operator of the impact tool 100 to change the rotation direction of the output shaft 130.

[0027] Reference Figures 6-8 The figure illustrates details of the construction of the rotor and fan assembly 124. As shown, the rotor and fan assembly 124 includes a rotor 180. The rotor 180 includes a plurality of metal layers or laminations 182 laminated together. Furthermore, the rotor and fan assembly 124 includes a fan 184 adjacent to the rotor 180. In a specific embodiment, the fan 184 is a metallic, plastic, ferromagnetic, or other suitable material, and the fan 184 is secured to the rotor 180. For example, the fan 184 is secured to the rotor 180 by one or more fasteners or adhesives. In another embodiment, the fan 184 is molded onto the rotor 180 and partially held in place by one or more channels 186 or tubes formed in the rotor 180, with molten material including the fan 184 flowing into one or more channels 186 or tubes during the molding process. Alternatively, the fan 184 is molded around one or more protrusions, such as magnet portions, extending from the face of the rotor 180.

[0028] like Figure 6 As shown, the fan 184 includes a generally disc-shaped base plate 188 and a central hub 190 extending from the base plate 188. As described in this application, the central hub 190 is fixed to the rotor 180. The fan 184 further includes a plurality of fan blades 192 or blades extending from the base plate 188 and radially outward from the central hub 190 on the same side as the central hub 190 (i.e., toward the rotor 180).

[0029] Figures 6-8Further illustration shows that the rotor 180 has a plurality of magnet pouches 200 extending axially along the length of the rotor 180 and passing through the entire length of the rotor 180, and perpendicularly through a plurality of metal layers 182. Each magnet pouch 200 has a first channel 202 and a second channel 204 on each side, the first channel 202 and the second channel 204 extending along the length of each magnet pouch 200 and adjacent to each side of the magnet pouch 200. Permanent magnets 206 are arranged within each magnet pouch 200.

[0030] Each magnet 206 includes an overlap portion 208, and each overlap portion 208 of each magnet 206 extends beyond the face of the rotor 180 adjacent to the fan 184. Figure 8 The fan 184 is formed with a plurality of magnet pouches 210 that extend at least partially into the central hub 190. Each magnet pouch 210 is configured to receive an overlap 208 of a corresponding magnet among magnets 206 disposed within the rotor 180. Furthermore, each magnet pouch 210 includes a pouch length LP, and the fan 184 defines a fan length LF. In this aspect, LP is greater than or equal to 0.01 × LF, for example, greater than or equal to 0.15 × LF, greater than or equal to 0.20 × LF, or greater than or equal to 0.25 × LF. In another aspect, LP is less than or equal to 0.55 × LF, for example, less than or equal to 0.50 × LF, less than or equal to 0.45 × LF.

[0031] ×LF, less than or equal to 0.40×LF, less than or equal to 0.35×LF, or less than or equal to 0.30×LF. It should be understood that LP can be between and include any minimum and maximum value of LP described in this application.

[0032] In a particular aspect, each magnet 206 defines a magnet length LM, and the overlapping portion 208 of each magnet 206 defines an overlap length LO. In one aspect, LO is equal to LP. Moreover, LO is greater than or equal to 0.05 × LM, for example, greater than or equal to 0.10 × LM, greater than or equal to 0.15 × LM, or greater than or equal to 0.20 × LM. In another aspect, LO is less than or equal to 0.50 × LM, for example, less than or equal to 0.45 × LM, less than or equal to 0.40 × LM, less than or equal to 0.35 × LM, less than or equal to 0.30 × LM, or less than or equal to 0.25 × LM. It should be understood that LO can be between and include any minimum and maximum value of LO described in this application.

[0033] On the other hand, rotor 180 defines rotor length LR. In this aspect, LO is greater than or equal to 0.15 × LR, for example, greater than or equal to 0.20 × LR, greater than or equal to 0.25 × LR, or greater than or equal to 0.30 × LR. On the other hand, LO is less than or equal to 0.60 × LR, for example, less than or equal to 0.55 × LR, less than or equal to 0.50 × LR, less than or equal to 0.45 × LR, less than or equal to 0.40 × LR, or less than or equal to 0.35 × LR. It should be understood that LO can be between and include any minimum and maximum value of LO described in this application.

[0034] On the other hand, LO is greater than or equal to 0.10 × LF, for example, greater than or equal to 0.15 × LF, greater than or equal to 0.20 × LF, or greater than or equal to 0.25 × LF. On the other hand, LO is less than or equal to 0.55 × LF, for example, less than or equal to 0.50 × LF, less than or equal to 0.45 × LF, less than or equal to 0.40 × LF, less than or equal to 0.35 × LF, or less than or equal to 0.30 × LF. It should be understood that LO can be between and include any minimum and maximum value of LO described in this application.

[0035] On the other hand, the overlapping portion 208 of each magnet 206 is pressed into the pocket 210 on the fan 184. On the other hand, the fan 184 is molded around the overlapping portion 208 of the magnets 206. It should be understood that embedding the overlapping portion 208 of each magnet 206 within the fan 184 saves space. Alternatively, larger magnets can be used without increasing the size of the tools used to install the rotor and fan assembly 124.

[0036] To operate the impact tool 100, the operator presses trigger 176 to start motor 118, which continuously drives gear assembly 120 and camshaft 140 via output shaft 130. When camshaft 140 rotates, cam ball 164 drives hammer 154 to rotate synchronously with camshaft 140, and hammer lugs engage with drive surfaces of anvil lugs to generate impact and rotatably drive anvil 150 and tool elements.

[0037] After each impact, the hammer 154 moves or slides rearward along the camshaft 140 away from the anvil 150, thereby disengaging the hammer lug from the anvil lug. As the hammer 154 moves rearward, cam balls 164 located in their respective cam grooves 162 in the camshaft 140 move rearward within their cam grooves 162. The spring 156 stores the energy of the rearward portion of the hammer 154 to provide a return mechanism for the hammer 154. After the hammer lugs disengage from their respective anvil lugs 220, as the spring 156 releases its stored energy, the hammer continues to rotate and move or slide forward toward the anvil 150 until the drive surface of the hammer lug re-engages with the drive surface of the anvil lug, causing another impact.

[0038] Although the rotor and fan assembly 124 is shown as incorporated into the rotary impact tool 100, it can alternatively be used with other rotary power tools (e.g., drills, reciprocating saws, rotary hammers, pulse drills, etc.) to support the output spindle or shaft. In such tools, the rotor and fan assembly 124 provides a more compact tool.

[0039] Although the present invention has been described in detail with reference to specific preferred embodiments, variations and modifications are still possible within the scope and spirit of one or more independent aspects of the present invention.

Claims

1. A power tool, comprising: case; A motor, supported within the housing, comprising a stator and a rotor, the rotor including a plurality of permanent magnets; and A fan coupled to the rotor to rotate together with the rotor relative to the stator, the fan comprising a plurality of magnet bags. Its features are: Each of the plurality of permanent magnets has an overlapping portion that extends beyond the face of the rotor and into the respective magnet pockets of the plurality of magnet pockets.

2. The power tool according to claim 1, characterized in that, The fan is made of ferromagnetic material.

3. The power tool according to claim 1, characterized in that, The rotor comprises a plurality of laminations.

4. The power tool according to claim 3, characterized in that, The plurality of laminations includes end laminations that define the face of the rotor.

5. The power tool according to claim 1, characterized in that, The fan is molded around the overlapping portion of the plurality of permanent magnets adjacent to the fan.

6. The power tool according to claim 1, characterized in that, The fan is molded separately from the rotor and is pressed onto the overlapping portion of the plurality of permanent magnets.

7. The power tool according to claim 1, characterized in that, The fan is fixed to the rotor with adhesive.

8. The power tool according to claim 1, characterized in that, The fan is secured to the rotor by fasteners.

9. A power tool, comprising: case; A motor supported within the housing, the motor including a stator and a rotor, the rotor including a plurality of permanent magnets, each permanent magnet having an overlapping portion extending beyond the face of the rotor; as well as A fan, coupled to the rotor, to rotate together with the rotor relative to the stator. Its features are: The fan includes a disc-shaped base plate, a central hub extending from the disc-shaped base plate, and a plurality of magnet bags extending into the central hub, wherein each magnet bag receives a respective overlapping portion of each of the permanent magnets.

10. The power tool according to claim 9, characterized in that, Each of the plurality of permanent magnets defines a magnet length, and the overlapping portion of each of the plurality of permanent magnets defines an overlap length, wherein the overlap length is greater than or equal to 0.05 × the magnet length.

11. The power tool according to claim 10, characterized in that, The overlap length is less than or equal to 0.5 × the magnet length.

12. The power tool according to claim 9, characterized in that, The rotor defines the rotor length, and the overlapping portion defines the overlap length, wherein the overlap length is greater than or equal to 0.15 × the rotor length.

13. The power tool according to claim 12, characterized in that, The overlap length is less than or equal to 0.6 × the rotor length.

14. The power tool according to claim 9, characterized in that, The fan defines the fan length, the overlapping portion defines the overlap length, and the overlap length is greater than or equal to 0.10 × the fan length.

15. The power tool according to claim 14, characterized in that, The overlap length is less than or equal to 0.55 × the fan length.

16. A power tool, comprising: case; A motor, supported within the housing, includes a stator and a rotor. The rotor includes a plurality of laminated metal layers, a plurality of magnet pouches extending vertically through the plurality of metal layers, and permanent magnets disposed within each of the plurality of magnet pouches, wherein each permanent magnet includes an overlapping portion extending beyond the face of the rotor; and A fan, coupled to the rotor, to rotate together with the rotor relative to the stator. Its features are: The fan includes a plurality of magnet bags, and the overlapping portion of each permanent magnet extends into one of the plurality of magnet bags.

17. The power tool according to claim 16, characterized in that, The fan includes a base plate, a central hub extending from the base plate, and a plurality of fan blades extending from the base plate and radially outward from the central hub in the same direction as the central hub.

18. The power tool according to claim 17, characterized in that, Each of the plurality of magnet bags extends toward the base plate into the central hub.

19. The power tool according to claim 16, characterized in that, The power tool further includes a first channel extending along the length of each magnet bag and adjacent to a first side of each magnet bag.

20. The power tool according to claim 19, characterized in that, The power tool further includes a second channel extending along the length of each magnet bag and adjacent to the second side of each magnet bag.

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