Power tool

Abstract

A power tool may include a housing including a first clamshell half and a second clamshell half and an end cap coupled to the first clamshell half and the second clamshell half, the end cap including a strut; a motor comprising a stator supported by the first clamshell half and the second clamshell half and a rotor rotatably supported by a rotor bearing; and an output member extending from the housing, the output member configured to be driven by the motor to drive a tool bit, where a strut of the end cap supports an inner race of the rotor bearing.

Description

[0001] This application is a divisional application of the Chinese Utility Model Patent Application No. 202323148344.0, filed on November 21, 2023, with the same title of “Power Tool”, filed by the same applicant.

[0002] Cross Reference to Related Applications

[0003] This application claims priority to U.S. Provisional Patent Application No. 63 / 384,519, filed on November 21, 2022, and U.S. Provisional Patent Application No. 63 / 384,522, filed on November 21, 2022, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0004] The present disclosure relates to power tools, and to power tools having a box enclosing a gear assembly, an impact assembly, and the like. BACKGROUND

[0005] Power tools having gear assemblies, impact assemblies, and the like typically include a gear box, which can also be referred to as an impact box or a front housing, to enclose and support these assemblies. The gear box is typically a separate component that is coupled to a main housing (e.g., a clamshell housing) of the power tool. SUMMARY

[0006] In some aspects, the technology described herein relates to a power tool comprising: a housing comprising a first clamshell half and a second clamshell half and an end cap coupled to the first clamshell half and the second clamshell half, the end cap comprising a strut; a motor comprising a stator supported by the first clamshell half and the second clamshell half and a rotor rotatably supported by a rotor bearing; and an output member extending from the housing, the output member configured to be driven by the motor to drive a bit, wherein the strut of the end cap supports an inner race of the rotor bearing.

[0007] In some aspects, the technology described herein relates to a power tool, wherein the rotor comprises a fan, and wherein the rotor bearing comprises an outer race received within the fan.

[0008] In some aspects, the technology described herein relates to a power tool, wherein a back surface of the rotor bearing is flush with a back surface of the fan.

[0009] In some aspects, the technology described herein relates to a power tool, wherein the end cap comprises a body and an insert molded within the end cap, and wherein the insert comprises the strut.

[0010] In some aspects, the technology described herein relates to a power tool, wherein the body of the end cap is made of a polymeric material, and wherein the insert is made of a material different from the polymeric material.

[0011] In some aspects, the technology described herein relates to a power tool, wherein the first and second clamshell halves are made of the polymeric material.

[0012] In some aspects, the technology described herein relates to a power tool, wherein the strut is integrally formed with the rest of the end cap as a single piece.

[0013] In some aspects, the technology described herein relates to a power tool, wherein the stator is directly supported by the first and second clamshell halves.

[0014] In some aspects, the technology described herein relates to a power tool, wherein the power tool further comprises a gear assembly directly supported by the first and second clamshell halves and operably coupled to the motor.

[0015] In some aspects, the technology described herein relates to a power tool, wherein the power tool further comprises an impact mechanism disposed within the housing between the first and second clamshell halves, the impact mechanism comprising: a camshaft, an anvil supported for rotation about an axis, and a hammer configured to impart a rotational impact to the anvil.

[0016] In some aspects, the technology described herein relates to a power tool, wherein a seam defined between the first and second clamshell halves extends along a front face of the housing.

[0017] In some aspects, the technology described herein relates to a power tool, wherein the anvil extends through a front face of the housing.

[0018] In some aspects, the technology described herein relates to a power tool, wherein the power tool further comprises an anvil support that rotationally supports the anvil, and wherein the anvil support is directly supported by the first and second clamshell halves.

[0019] In some aspects, the technology described herein relates to a power tool, wherein the anvil support comprises a bearing or bushing disposed in a recess of the housing.

[0020] In some aspects, the technology described herein relates to a power tool, wherein the housing comprises a sealed chamber that encloses the impact mechanism, and wherein the sealed chamber is sealed by a sealing element disposed in the housing.

[0021] In some aspects, the technology described herein relates to a power tool, wherein the gear assembly includes a pinion gear coupled to the motor, a plurality of planet gears meshed with the pinion gear, and a ring gear meshed with the plurality of planet gears and directly supported by the first and second clamshell halves.

[0022] Other features and aspects of the present disclosure will become apparent from consideration of the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a perspective view of a power tool according to an embodiment of the present disclosure.

[0024] Figure 2 is a partial cross-sectional view of the power tool of Figure 1 taken along line 2-2 of Figure 1 is a partial cross-sectional view of the power tool of

[0025] Figure 3 is a rear view of a portion of the power tool of Figure 1

[0026] Figure 4 is a front view of a portion of the power tool of Figure 1

[0027] Figure 5 is a cross-sectional view of a portion of the power tool of Figure 1 DETAILED DESCRIPTION

[0028] Before any embodiments of the present disclosure are explained in detail, it is to be understood that the application of the present disclosure is not limited to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The present disclosure is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0029] Figure 1 An embodiment of a power tool 10 in the form of a rotary impact tool, and more specifically, an impact driver, is illustrated. The power tool 10 includes a housing 14 defined by a mated first and second clamshell halves 18a, 18b (also referred to as first and second housing portions). The illustrated first and second clamshell halves 18a, 18b are coupled together at a separation plane or joint 20 by a first plurality of fasteners 19 (e.g., screws, bolts, etc.). The first and second clamshell halves 18a, 18b are configured to be separable along the separation plane 20 to allow access to an interior of the housing 14. The first and second clamshell halves 18a, 18b are configured to be reattachable along the separation plane 20 to allow reassembly of the housing 14. Figure 2 ​​​). In the illustrated embodiment, the seam 20 is positioned along a longitudinal center plane of the power tool 10. The housing 14 includes a head housing portion 22 and a handle portion 26 extending downward from the head housing portion 22. In the illustrated embodiment, the handle portion 26 is covered or surrounded by a grip portion 28. The illustrated head housing portion 22 further includes an end cap 30 coupled to rear portions of the first and second clamshell halves 18a, 18b (e.g., by a second plurality of fasteners 31). In the illustrated embodiment, the end cap 30 spans the two clamshell halves 18a, 18b. In other embodiments, the end cap 30 can be integrally formed with the first and second clamshell halves 18a, 18b such that the head housing portion 22 is entirely defined by the clamshell halves 18a, 18b. The power tool 10 further includes a battery 34 removably coupled to a battery receptacle 38 at a bottom end or foot 40 of the handle portion 26.

[0030] Referring to Figure 2 , a motor 42 (e.g., a brushless DC electric motor), a gear assembly 46, and an impact mechanism 50 are enclosed within the head housing portion 22. In other words, the motor 42, the gear assembly 46, and the impact mechanism 50 are enclosed within the clamshell halves 18a, 18b and the end cap 30. The motor 42 includes a stator 54 and a rotor 58. The stator 54 is directly supported by the clamshell halves 18a, 18b. The stator 54 can include, for example, a stator frame and a plurality of coils or windings. The rotor 58 includes a plurality of laminations and embedded permanent magnets, an output shaft 62, and a fan 66. The output shaft 62 and the fan 66 are coupled to co-rotate with the rotor 58 about an axis 70 relative to the stator 54. A sensor PCB 74 including a plurality of sensors (e.g., Hall effect sensors) for detecting rotation of the rotor 58 is coupled to a front side of the frame of the stator 54. In other embodiments, the sensor PCB 74 can be coupled to a rear side of the frame of the stator 54.

[0031] Referring back to Figure 1 , the housing 14 includes vents 78a, 78b, 78c to enable airflow through the housing 14. The airflow is configured to cool the motor 42 and / or other electronic components (e.g., PCBs, switching electronics, etc.) within the housing 14. In the illustrated embodiment, the housing 14 includes a first plurality of intake vents 78a formed in the head housing portion 22, a second plurality of intake vents 78b formed in the foot 40, and a plurality of exhaust vents 78c formed in the head housing portion 22 adjacent to the end cap 30. During operation, rotation of the fan 66 can draw cooling air into the housing 14 through the intake vents 78a, 78b and then exhaust the cooling air through the exhaust vents 78c.

[0032] Referring back to Figure 2In the illustrated embodiment, the gear assembly 46 includes a pinion gear 82 coupled to the output shaft 62, a plurality of planetary gears 86 meshed with the pinion gear 82, and a ring gear 90 meshed with the planetary gears 86. In some embodiments, the pinion gear 82, the planetary gears 86, and the ring gear 90 can be spur gears, helical gears, or other suitable types of gears. The pinion gear 82 is rotatably supported by a front rotor bearing 94 (e.g., a ball bearing). The front rotor bearing 94 is disposed within a cavity 100 in the camshaft 98 and includes an inner race 95 and an outer race 96. The inner race 95 is coupled to the pinion gear 82 and rotates with the pinion gear 82. The outer race 96 is coupled to the camshaft 98 and rotates with the camshaft 98. In some embodiments, the inner race 95 can include lugs that are received by recesses in the pinion gear 82 to further secure the inner race 95 to the pinion gear 82. In other embodiments, the pinion gear 82 can include lugs and the inner race 95 can include recesses that receive the lugs. The ring gear 90 is rotationally fixed within a recess 102 in the head housing portion 22. In other words, the ring gear 90 is directly supported by the clamshell halves 18a, 18b. In some embodiments, the ring gear 90 can include lugs that are received in additional recesses or grooves within the head housing portion 22 to further secure the ring gear 90 within the head housing portion 22.

[0033] With continued reference Figure 2The planetary gears 86 are coupled to a camshaft 98 of the impact mechanism 50 such that the camshaft 98 functions as a planetary carrier. Accordingly, rotation of the output shaft 62 causes the planetary gears 86 to rotate, which then travel along the inner circumference of the ring gear 90, thereby causing the camshaft 98 to rotate. The impact mechanism 50 further includes a hammer 106 supported on the camshaft 98 and axially slidable relative thereto, a spring 110 partially disposed within the hammer 106 and configured to bias the hammer 106 along the axis 70 toward the front side of the power tool 10, and an anvil 114 (also referred to as an output member). The hammer 106 is configured to axially reciprocate along the camshaft 98 to impart rotational impacts to the anvil 114 in response to rotation of the camshaft 98. The anvil 114 is rotationally supported for rotation about the axis 70 by an output member support or anvil support, which in the illustrated embodiment includes a bearing 118 (also referred to as an anvil bearing 118). The anvil bearing 118 is retained within a recess 122 defined by the front portions of the clamshell halves 18a, 18b. As such, the anvil bearing 118 is directly supported by the clamshell halves 18a, 18b. In the illustrated embodiment, a bushing 126 is received in the recess 122 adjacent to the front side of the anvil bearing 118. The bushing 126 (also directly supported by the clamshell halves 18a, 18b) abuts the anvil bearing 118 to secure the anvil bearing 118 and prevent movement of the anvil bearing along the axis 70. In some embodiments, the anvil 114 can additionally or alternatively be rotationally supported by the bushing 126. In some embodiments, the anvil 114 can be rotationally supported by a plurality of bearings or a plurality of bushings. As such, the anvil support can include one or more bushings or bearings. In some embodiments, the anvil support can be insert molded within the housing 14. In other embodiments, the anvil support can be an integral part of the clamshell halves 18a, 18b. In such embodiments, the clamshell halves 18a, 18b can collectively define a bearing surface directly supported by the remainder of the clamshell halves 18a, 18b and configured to rotationally support the anvil 114.

[0034] With continued reference to Figure 2The head housing portion 22 defines a chamber that encloses the gear assembly 46 and the impact mechanism 50. This chamber is at least partially sealed by sealing elements 132 made of a flexible / semi-flexible material (e.g., rubber, neoprene, silicone, etc.). The sealing elements 132 can be disposed within corresponding grooves in each of the clamshell halves 18a, 18b and can optionally be insert molded within the clamshell halves 18a, 18b. The sealing elements 132 inhibit the escape of grease, oil, etc. that can be used to lubricate the gear assembly 46 and the impact mechanism 50 from the chamber. In the illustrated embodiment, the chamber is bounded at its rear side by a partition wall 134. The partition wall 134 is disposed between the motor 42 and the gear assembly 46. In some embodiments, one or more additional sealing elements (e.g., gaskets, o-rings, etc.) can seal between the partition wall 134 and the clamshell halves 18a, 18b.

[0035] With continued reference to Figure 2 The end cap 30 includes a strut 138 that extends along the axis 70 from the body of the end cap 30 toward the front side of the power tool 10. In the illustrated embodiment, the strut 138 is integrally formed with the rest of the end cap 30 as a single piece. The strut 138 is received within a bearing 142 (also referred to as a rear rotor bearing 142). The rear rotor bearing 142 includes an inner race 143 and an outer race 144. The strut 138 contacts the inner race 143. More specifically, the inner race 143 is fixedly coupled to the strut 138 such that the inner race 143 cannot rotate. The outer race 144 is received within and coupled to the fan 66. The rear rotor bearing 142 is configured to support the fan 66, and the outer race 144 rotates with the fan 66 during operation. The fan 66 supports the output shaft 62, which in turn supports the rotor 58. Thus, the rear rotor bearing 142 supports a rear end portion of the rotor assembly, which includes the rotor 58, the output shaft 62, and the fan 66. Similar to the front rotor bearing 94, in some embodiments, the rear rotor bearing 142 can include lugs or apertures on the inner race 143 and / or the outer race 144 that engage with lugs or apertures located on the respective surfaces that contact the inner race 143 and the outer race 144. In the illustrated embodiment, a rear surface of the rear rotor bearing 142 is flush with a rear surface of the fan 66. In other words, the entire rear rotor bearing 142 is disposed within the fan 66. This achieves a more compact length of the power tool 10 along the axis 70. However, in other embodiments, the rear rotor bearing 142 can be only partially recessed within the fan 66.

[0036] The front (or inner) side of the illustrated end cap 30 includes a support member 148 that contacts the clamshell halves 18a, 18b to further secure the end cap 30 to the clamshell halves 18a, 18b (in addition to the strut 138 and the rear rotor bearing 142). The support member 148 is integrally formed with the rest of the end cap 30 as a single piece. In some embodiments, the support member 148 can be a separate piece that is coupled to the end cap 30. The support member 148 is disposed between the front side of the end cap 30 and the front side of the power tool 10. The support member 148 is configured to support the front end portion of the rotor assembly, which includes the rotor 58, the output shaft 62, and the fan 66. In the illustrated embodiment, the support member 148 is disposed within the fan 66. In other embodiments, the support member 148 can be disposed outside of the fan 66. Figure 2). In some embodiments, the support member 148 is an annular ring. In other embodiments, the support member 148 can include a plurality of individual protrusions that contact the clamshell halves 18a, 18b.

[0037] With continued reference to Figure 2 , the body of the end cap 30 has a width W measured parallel to the axis 70. In some embodiments, the width W is about 3 mm or less. In some embodiments, the width W is between 2.5 mm and 3 mm. In other embodiments, the end cap 30 can have another width W. In the illustrated embodiment, the relatively small width of the end cap 30 allows the power tool 10 to have a very compact length along the axis 70.

[0038] In Figure 3 , the end cap 30 includes a generally flat back surface 152 on a side of the end cap 30 opposite the clamshell halves 18a, 18b. In the illustrated embodiment, the back surface 152 of the end cap 30 is generally circular. The end cap 30 further includes a plurality of ears 156 extending from the end cap 30 in a direction away from the axis 70. The ears 156 are shaped to provide support to the portion of the end cap 30 that receives the fasteners 31. In the illustrated embodiment, the ears 156 are offset from the back surface 152 such that the ears 156 are not on a plane defined by the back surface 152 (as best shown in FIG. 6). Figure 1 In other words, the ears 156 are offset from the back surface 152 in a direction along the axis 70 toward the front side of the power tool 10.

[0039] In the illustrated embodiment, the end cap 30 is made of the same material as the clamshell halves 18a, 18b (e.g., a polymeric material including, but not limited to, nylon-66, ABS, fiber-reinforced polymeric material, or glass-reinforced polymeric material). In other embodiments, the end cap 30 can be made of a material that is stronger than the rest of the housing 14 (e.g., steel, carbon fiber-reinforced nylon, etc.) to achieve sufficient strength to securely support the rear rotor bearing 142 while maintaining the small width W.

[0040] As Figure 4 shown, the seam 20 between the first and second clamshell halves 18a, 18b extends along a rounded front face 160 of the head housing portion 22. Two of the plurality of fasteners 19 are disposed in cutouts 164 in the front face 160 and extend from the first clamshell half 18a to the second clamshell half 18b. The anvil 114 protrudes through the front face 160 Figure 2 and is configured to attach to a bit and / or drive a bit. The anvil 114 is shown concentric with the front face 160 and between two of the plurality of fasteners 19.

[0041] With reference to Figure 1The clamshell halves 18a and 18b shown are separate components that are joined together to form most of the outer surface of the power tool 10. The clamshell halves 18a and 18b can be molded from a polymer material (e.g., blow molding, injection molding, etc.). In some embodiments, the clamshell halves 18a and 18b and the end cap 30 define a head housing portion 22. In other embodiments without end caps, the clamshell halves 18a and 18b may define the head housing portion 22. The clamshell halves 18a and 18b provide sufficient rigidity and support for the operation of the motor 42, gear assembly 46, and impact mechanism 50, avoiding the need for an additional gearbox or front housing portion. The absence of a separate gearbox makes the power tool 10 more compact and lightweight than power tools with separate gearboxes. Gearboxes are typically made of metal, which is relatively heavy compared to the polymer material of the clamshell halves 18a and 18b. The absence of a gearbox also reduces the total number of parts required for the power tool 10 and simplifies manufacturing.

[0042] Figure 5 Another end cap 230 for use with power tool 10 is shown. The shown end cap 230 includes an insert 234 molded (e.g., embedded) within the body of the end cap 230. In the shown embodiment, the insert 234 is made of a material different from that of the end cap 230. For example, the insert 234 is made of a high-strength material (e.g., steel, carbon fiber strip, carbon fiber sheet, etc.) that is relatively stronger than the material of the body of the end cap 230. The shown insert 234 includes a support 238 that extends along axis 70 from the end cap 230 toward the front of the power tool 10 and into the rear rotor bearing 142. The support 238 is coupled to an inner ring 143 such that the support 238 supports the inner ring 143. The inner ring 143 may be press-fitted to the support 238 or secured to the support 238 in any other suitable manner. The insert 234 also includes an insert support 242 extending radially from the support 238 within the end cap 230. Insert support 242 is configured to secure insert 234 within end cap 230. In some embodiments, insert support 242 is a generally circular disc. In other embodiments, insert support 242 may be a plurality of protrusions. In the illustrated embodiment, the rear surface of rear rotor bearing 142 is flush with the rear surface of fan 66. End cap 230 may include one or more exhaust ports 246 for discharging cooling air moved by fan 66. End cap 230 may also include gripping portions 250.

[0043] While this disclosure has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the described disclosure. For example, power tool 10 is described and shown herein as an impact tool; however, in other embodiments, the integrated gearbox may be incorporated into other types of power tools, including continuous torque tools such as drills, electric screwdrivers, etc. In such embodiments, the anvil 114 may be replaced by a motor-driven spindle or other output component.

[0044] The various features of this disclosure are set forth in the appended claims.

Claims

1. A power tool, characterized in that, include: A shell, the shell comprising a first clam shell half and a second clam shell half and an end cap connected to the first clam shell half and the second clam shell half, the end cap comprising a support. The motor includes a stator supported by the first clamshell half and the second clamshell half, and a rotor rotatably supported by a rotor bearing. as well as An output member extending from the housing is configured to be driven by the motor to drive the cutter head. The end cap's support struts support the inner ring of the rotor bearing.

2. The power tool as described in claim 1, characterized in that, The rotor includes a fan, and the rotor bearing includes an outer ring received within the fan.

3. The power tool as described in claim 2, characterized in that, The rear surface of the rotor bearing is flush with the rear surface of the fan.

4. The power tool as described in any one of claims 1 to 3, characterized in that, The end cap includes a body and an insert molded within the end cap, wherein the insert includes the support.

5. The power tool as described in claim 4, characterized in that, The body of the end cap is made of a polymer material, and the insert is made of a material different from the polymer material.

6. The power tool as described in claim 5, characterized in that, The first and second clam shell halves are made of the polymer material.

7. The power tool as described in any one of claims 1 to 3, characterized in that, The support and the rest of the end cap are integrally formed as a single piece.

8. The power tool as described in any one of claims 1 to 3, characterized in that, The stator is directly supported by the first clamshell half and the second clamshell half.

9. The power tool as described in any one of claims 1 to 3, characterized in that, It further includes a gear assembly that is directly supported by the first clamshell half and the second clamshell half and is operatively connected to the motor.

10. The power tool as claimed in any one of claims 1 to 3, characterized in that, The invention further includes an impact mechanism disposed within the shell between the first shell half and the second shell half, the impact mechanism comprising: Camshaft, Anvil, which is supported to rotate about an axis, and A hammer, configured to apply a rotating impact to the anvil.

11. The power tool as claimed in claim 10, characterized in that, The seam between the first clam shell half and the second clam shell half extends along the front of the shell.

12. The power tool as claimed in claim 11, characterized in that, The anvil extends through the front of the housing.

13. The power tool as described in claim 10, characterized in that, It further includes an anvil support member that rotatably supports the anvil, wherein the anvil support member is directly supported by the first clam shell half and the second clam shell half.

14. The power tool as described in claim 13, characterized in that, The anvil support includes a bearing or bushing disposed in a recess of the housing.

15. The power tool as described in claim 10, characterized in that, The housing includes a sealed chamber that encloses the impact mechanism, and wherein the sealed chamber is sealed by a sealing element disposed in the housing.

16. The power tool as described in claim 9, characterized in that, The gear assembly includes: A small gear, which is connected to the motor. Multiple planetary gears, which mesh with the pinion, and The ring gear meshes with the plurality of planetary gears and is directly supported by the first clamshell half and the second clamshell half.

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