Power tool

Abstract

A power tool includes a housing, a motor including a shaft configured to rotate about an axis, a gear assembly operably coupled to the motor, the gear assembly including a ring gear fixed relative to the housing and a plurality of planet gears meshed with the ring gear, a drive assembly operably coupled to the gear assembly to receive torque from the shaft through the gear assembly, the drive assembly including a cam shaft, an anvil, and a hammer configured to reciprocate along the cam shaft to impart rotational impacts to the anvil in response to rotation of the cam shaft, an impact box coupled to the housing opposite the end cap, and an intermediate housing disposed between the ring gear and the impact box such that the ring gear, the impact box, and the intermediate housing at least partially define a sealed chamber containing the gear assembly and the drive assembly.

Description

[0001] This application is a divisional application of Chinese utility model patent application No. 202290000796.9, filed on December 1, 2022, entitled "Rotating Impact Tool", filed by the same applicant.

[0002] Cross-references to related applications This application claims priority to U.S. Provisional Patent Application No. 63 / 284,887, filed December 1, 2021, the entire contents of which are incorporated herein by reference. Technical Field

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

[0004] Rotary impact tools are typically used to apply impact rotational force to tool elements or workpieces (e.g., fasteners) or to intermittently apply torque to tighten or loosen fasteners. Utility Model Content

[0005] In one aspect, this application relates to a power tool comprising: a housing including a first portion and a second portion joined together at a joint, and an end cap coupled to the first portion and the second portion; a motor mounted within a motor housing portion of the housing defined by the first portion and the second portion, the motor including a shaft configured to rotate about an axis; a gear assembly operatively coupled to the motor, the gear assembly including a ring gear fixed relative to the housing and a plurality of planetary gears meshing with the ring gear; a drive assembly operatively coupled to the gear assembly to receive torque from the shaft via the gear assembly, the drive assembly including a camshaft, an anvil, and a hammer configured to reciprocate along the camshaft to apply a rotational impact to the anvil in response to rotation of the camshaft; an impact chamber coupled to the housing opposite to the end cap; and an intermediate housing disposed between the ring gear and the impact chamber, such that the ring gear, the impact chamber, and the intermediate housing at least partially define a sealed chamber containing the gear assembly and the drive assembly.

[0006] In some respects, the housing includes a partition wall extending between the motor and the gear assembly, wherein the shaft extends through an opening in the partition wall, and wherein the ring gear sits against the partition wall.

[0007] In some respects, the power tool further includes a lighting assembly comprising a cover coupled to the front end of the impact chamber opposite to the intermediate housing, and a plurality of LEDs.

[0008] In some respects, the ring gear includes a toothed portion and a flange portion extending from the toothed portion, wherein the flange portion rotatably supports the camshaft.

[0009] In some respects, the housing and the impact chamber are joined together by one or more fasteners, which are received in inserts fixed within the housing and are made of metallic material.

[0010] In some aspects, the power tool further includes a rear bearing and a front bearing supporting the shaft of the motor, wherein the ring gear includes a boss extending rearward along the axis, and wherein the front bearing is received within and supported by the boss.

[0011] In some respects, the motor includes a stator, and wherein the measured distance between the front edge of the rear bearing and the rear edge of the front bearing is less than the outer diameter of the stator.

[0012] In some respects, the first part and the second part directly support the stator.

[0013] In some respects, the rear bearing is supported by the end cap.

[0014] In some respects, the outer diameter of the stator is 50 mm to 70 mm.

[0015] In some aspects, the housing includes a battery socket, and the power tool further includes a battery detachably connected to the battery socket and configured to power the motor.

[0016] In some aspects, the battery socket includes an elastomeric element that can engage with the battery when it is connected to the power tool.

[0017] In another aspect, this utility model provides a power tool comprising: a housing including a first portion and a second portion joined together at a joint, and an end cap connected to the first portion and the second portion; a motor mounted within a motor housing portion of the housing defined by the first portion and the second portion, the motor including a shaft configured to rotate about an axis; a gear assembly operatively coupled to the motor, the gear assembly including a ring gear fixed relative to the housing and a plurality of planetary gears meshing with the ring gear; a drive assembly operatively coupled to the gear assembly to receive torque from the shaft via the gear assembly, the drive assembly including a camshaft, an anvil, and a hammer configured to reciprocate along the camshaft to apply a rotational impact to the anvil in response to rotation of the camshaft; an impact chamber coupled to the housing opposite to the end cap; and an intermediate housing disposed between the ring gear and the impact chamber, such that the ring gear, the impact chamber, and the intermediate housing at least partially define a sealed chamber containing the gear assembly and the drive assembly.

[0018] Other features and aspects of this invention will become clear upon consideration of the detailed description and accompanying drawings. Any feature(s) described herein with respect to one aspect or embodiment may be combined with any other feature(s) described herein with respect to any other aspect or embodiment, where appropriate and applicable. Attached Figure Description

[0019] Figure 1 This is a perspective view of a power tool according to an embodiment of the present invention.

[0020] Figure 2A It is along Figure 1 The line 2A-2A is intercepted. Figure 1 The cross-sectional view of the power tool is shown with the power tool's battery pack removed, and illustration numbers are shown around a portion of the power tool's sealing system.

[0021] Figure 2B Is it when positioned at Figure 2A The area shown in the illustration number is an enlarged view of a portion of an alternative sealing system that can be used with power tools.

[0022] Figure 2C yes Figure 1 A cross-sectional view of a portion of a power tool.

[0023] Figure 3 yes Figure 1 A quarter section view of the power tool.

[0024] Figure 4 yes Figure 1A perspective view of the handle portion of a power tool, in which the first housing portion is hidden.

[0025] Figure 5 It is along Figure 1 The line cut from 5-5 Figure 1 A cross-sectional view of the handle portion of a power tool.

[0026] Figure 6 yes Figure 4 Partially exploded bottom 3D view of the handle section.

[0027] Figure 7 It is along Figure 4 The sectional view taken from line 7-7 shows the battery pack removed.

[0028] Figure 8 yes Figure 1 A partial exploded view of the power tool.

[0029] Figure 9 yes Figure 1 A side view of the power tool, in which the first housing portion is hidden to show the motor, gears, and drive components.

[0030] Figure 10 yes Figure 1 A side perspective perspective view of the power tool, which conceals the first housing portion and part of the gear assembly.

[0031] Figure 11 yes Figure 1 Power tools along Figure 1 The sectional view taken from line 11-11.

[0032] Figure 12 This is a separate view of the sealing system in Figure 2.

[0033] Figure 13 According to another embodiment, it is compatible with Figure 1 A three-dimensional diagram of a sealing system used in conjunction with power tools.

[0034] Figure 14 yes Figure 13 An enlarged view of the sealing connection of the sealing system.

[0035] Figure 15 and Figure 16 yes Figure 1 The dimensions of the power tool are shown in the view, illustrating certain dimensions associated with the power tool in some embodiments.

[0036] Figure 17A This is a cross-sectional view of a power tool according to another embodiment of the present invention.

[0037] Figure 17BIs Figure 17A An enlarged view of a portion of the sealing system in the area shown in the illustration number.

[0038] Before explaining any embodiment of this utility model in detail, it should be understood that the application of this utility model is not limited to the details of the component construction and arrangement set forth in the following description or shown in the following drawings. This utility model can have other embodiments and can be practiced or performed in various ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting. Detailed Implementation

[0039] Figure 1 An embodiment of a power tool in the form of a rotary impact tool, more specifically an impact wrench 10, is shown. The impact wrench 10 includes a housing 14 having a motor housing portion 18, an impact box or front housing portion 22 connected to the motor housing portion 18 (e.g., by a plurality of fasteners 24), and a handle portion 26 extending downward from the motor housing portion 18. In the illustrated embodiment, the handle portion 26 and the motor housing portion 18 are defined by cooperating first and second clamshell halves or first and second housing portions 28a, 28b.

[0040] The illustrated housing 14 also includes an end cap 30 connected to the motor housing portion 18 opposite to the front housing portion 22. The clamshell halves 28a, 28b can be joined (e.g., fastened) together at an interface or seam 31. In the illustrated embodiment, the end cap 30 is continuous and can be pressed or fitted onto the rear ends of the clamshell halves 28a, 28b. In other words, the end cap 30 may not include the two halves, allowing the end cap 30 to extend over the seam 31. The end cap 30 is secured by a plurality of fasteners 120 ( Figure 3 and Figure 11 It is connected to the motor housing portion 18. In other embodiments, the end cap 30 may be integrally formed with the motor housing portion 18.

[0041] The impact wrench 10 further includes an illumination assembly 32 having one or more light sources 33. The illustrated illumination assembly 32 surrounds the front housing portion 22 and can be used as a cover at the front end of the front housing portion 22. In some embodiments, the illumination assembly 32 may include one or more lenses covering the one or more light sources 33. In some embodiments, the one or more light sources 33 may be light-emitting diodes (LEDs) arranged around a center point of the illumination assembly 32.

[0042] Reference Figure 1The impact wrench 10 includes a battery 34, which is removably connected to a battery socket 38 located at the bottom end of the handle portion 26 or the foot 40. When the battery 34 is connected to the battery socket 38, the motor 42 ( Figure 2A The battery 34 receives power from the battery 34 via a connector, pad, and / or battery terminal 43 supported within the motor housing portion 18 and via a battery socket 38. Figure 1 As shown, the foot 40 may include one or more vents 44 (e.g., air vents, cooling vents, etc.). In the illustrated embodiment, the handle portion 26 of the clam shell halves 28a, 28b may be covered or surrounded by the gripping portion 45.

[0043] Battery 34 may be a power tool battery pack typically used to power power tools such as drills and chainsaws (e.g., an 18-volt rechargeable battery pack, or an M18 REDLITHIUM battery pack sold by Milwaukee Electric Tool Corporation). Battery 34 may include lithium-ion (Li-ion) battery cells. In alternative embodiments, the battery pack may have different chemistry (e.g., nickel-cadmium (NiCa or NiCad), nickel-hydride, etc.). In the illustrated embodiment, battery 34 is an 18-volt battery pack. In alternative embodiments, the capacity of battery 34 may vary (e.g., the battery may be a 4-volt battery pack, a 28-volt battery pack, a 40-volt battery pack, or any other voltage battery pack suitable for powering the impact wrench 10).

[0044] refer to Figure 2A and Figure 3 In the illustrated embodiment, motor 42 is a brushless direct current (“BLDC”) motor having a stator 46 and a rotor, with output shaft 50 rotatable relative to stator 46 about axis 54. In other embodiments, other types of motors may be used. Fan 58 is coupled to output shaft 50 behind motor 42 to generate airflow. In the illustrated embodiment, motor 42 is operable (e.g., controlled) without the use of Hall effect sensors. Therefore, a printed circuit board adjacent to the front or rear end of motor 42 is not required, allowing for a shorter length to be accommodated in housing 14.

[0045] The impact wrench 10 also includes a switch 62 (e.g., a trigger switch; FIG. 2) supported by a housing 14, which selectively electrically connects a motor 42 (e.g., via a suitable control circuitry disposed on one or more printed circuit board assemblies (“PCBA”) 63a, 63b) to a battery 34 to provide DC power to the motor 42. In other embodiments, the impact wrench 10 may include a power cord for electrically connecting the switch 62 and the motor 42 to an AC power source. As another alternative, the impact wrench 10 may be configured to operate using a different power source (e.g., a pneumatic or hydraulic power source, etc.).

[0046] Now refer to Figure 4 The first PCBA 63a is positioned within the handle portion 26 and is electrically connected to the motor 42, switch 62, and battery socket 38. In the illustrated embodiment, the first PCBA 63a includes a plurality of semiconductor switching elements (e.g., MOSFETs, IGBTs, etc.) that control and distribute power to the windings in the stator 46 to rotate the rotor and output shaft 50. The first PCBA 63a may also include one or more microprocessors, machine-readable non-transitory memory elements, and other electrical or electronic components for providing operational control to the impact wrench 10.

[0047] Continue to refer to Figure 4 The impact wrench 10 shown includes a second PCBA 63b located in the foot 40 of the impact wrench 10. The second PCBA 63b includes one or more indicators 60 configured to indicate the operating state or mode of the impact wrench 10. The second PCBA 63b may also include one or more communication modules (e.g., Bluetooth, Wi-Fi, etc.) for linking with external devices to control the operating state or mode of the impact wrench 10.

[0048] refer to Figure 4 and Figure 5 A frame 64 (e.g., one or more stamped parts, shielding elements, plates, and / or the like) is embedded within the handle portion 26 and at least partially surrounds the first PCBA 63a. In the illustrated embodiment, the frame 64 includes a plurality of frame members located within the handle portion 26 adjacent to the grip portion 45. For example, each of the clamshell halves 28a, 28b may include embedded frame members to collectively define the frame 64. In the illustrated embodiment, the frame members are formed as stamped plates, the curved areas of which generally match the curvature of the grip portion 45.

[0049] Frame 64 reinforces handle portion 26 to resist, for example, flexing, cracking, bending, and / or similar conditions. Frame 64 is made of a different material than handle portion 26 and is preferably made of a high-strength material (such as metal, metal composite, or another reinforcing material such as carbon fiber, fiber-reinforced polymer, etc.). The illustrated frame 64 is embedded (e.g., molded) within handle portion 26, thus allowing the walls of handle portion 26 to be thinner while maintaining sufficient strength to reduce the weight of the impact wrench 10 and provide more volume within handle portion 26 to accommodate the first PCBA 63a. In the illustrated embodiment, frame 64 extends from battery socket 38 toward switch 62 and at least partially beyond the switch.

[0050] In the illustrated embodiment, frame 64 includes a central groove-shaped recess 65a extending along the length of handle portion 26. Recess 65a provides additional clearance to accommodate electronic components, such as one or more capacitors, on the first PCBA 63a. Frame 64 also includes a plurality of circular recesses 65b arranged around the periphery of frame 64. Recesses 65b can provide flow channels for the polymer material of handle portion 26 during molding of handle portion 26, thereby further securing frame 64 within handle portion 26.

[0051] In the illustrated embodiments, such as Figure 5 As best shown, the clamshell halves 28a, 28b are positioned to at least partially overlap each other at the seam 31, and the gripping portion 45 is shaped to surround the mating clamshell halves 28a, 28b. Fasteners (e.g., fastener 24) may be threaded, pinned, inserted, etc., into each of the clamshell halves 28a, 28b to further secure the housing 14 of the handle portion 26 in a closed or substantially sealed position. In some embodiments, the fastener 24 in the handle portion 26 may also extend through the frame 64.

[0052] Now refer to Figure 6 and Figure 7 The battery socket 38, adjacent to the foot 40 and including the battery terminal 43, further includes a ramp or pawl 68 configured to engage with the battery 34 when the battery 34 is connected to the battery socket 38. In some embodiments, the pawl 68 is made of a resilient elastomeric material, such as rubber. In other embodiments, the pawl 68 may be spring-biased to engage with the battery 34. In the illustrated embodiment, one or more inserts 71 (such as elastomeric plugs or rubber plugs) may be inserted into the portion of the foot 40 near the front end of the battery socket 38. The pawl 68 and the inserts 71 occupy the tolerance space between the battery 34 and the socket 38 to provide a tight fit between the battery 34 and the socket 38.

[0053] In the illustrated embodiment, the battery socket 38 further includes a frame 69 supported (e.g., positioned, inserted, shaped, formed, etc.) within the battery socket 38. The illustrated frame 69 is made of one or more metal stampings (or any other suitable high-strength material) and provides additional strength and durability to the guide rail 49 that is slidably connected to and supports the battery 34. Similar to the frame 64, the frame 69 may be embedded (e.g., shaped) within the respective clamshell halves 28a, 28b.

[0054] Now refer to Figures 2A to 3 The impact wrench 10 further includes a gear assembly 66 driven by an output shaft 50 and an impact mechanism 70 coupled to the output end of the gear assembly 66. The impact mechanism 70 may also be referred to herein as the drive assembly 70. The gear assembly 66 can be configured in any of a variety of different ways to provide speed reduction between the output shaft 50 and the input end of the drive assembly 70. The gear assembly 66 is at least partially housed within a gearbox or gear housing 74 formed by the housing 14. Specifically, clamshell halves 28a, 28b form recesses 75 that directly receive the gear assembly 66 and at least partially form the gear housing 74. As will be described in more detail below, the gear assembly 66 and gear housing 74 of the impact wrench 10 further reduce the overall length of the impact wrench 10.

[0055] In the illustrated embodiments, please refer to the specific details. Figures 2A to 3 The front end portion 78 of the motor housing portion 18 receives and overlaps a portion of the front housing portion 22. In the illustrated embodiment, the gear housing 74 and the front housing portion 22 may contain a lubricant (such as grease or oil) to facilitate smooth operation of the impact wrench 10. As will be discussed in more detail below, the impact wrench 10 further includes a sealing system 80 that at least partially positions the gearbox 74 between the gearbox 74 and the front housing portion 22 to prevent lubricant leakage from the front housing portion 22.

[0056] like Figure 3 The gear assembly 66 shown includes: a helical pinion 82 formed on the output shaft 50 of the motor 42; a plurality of helical planetary gears 86 meshing with the helical pinion 82; and a helical ring gear 90 meshing with the planetary gears 86 and rotatably fixed within a housing 14 (e.g., gear housing 74). More specifically, the ring gear 90 shown includes a plurality of lugs 170 ( Figure 8 and Figure 9 In the illustrated embodiment, the lug 170 of the ring gear 90 is fitted into a groove 75 formed by the clamshell halves 28a and 28b to support and constrain the ring gear 90 in the rotational direction. The rearward-facing side of the ring gear 90 rests against a partition wall 113 formed by the clamshell halves 28a and 28b. The partition wall 113 separates the gear housing 74 from the motor 42.

[0057] Continue to refer to Figure 3 Planetary gears 86 are coupled to the camshaft 94 of the drive assembly 70, such that the camshaft 94 acts as a planet carrier. Accordingly, rotation of the output shaft 50 causes the planetary gears 86 to rotate, and these planetary gears then travel along the inner circumference of the ring gear 90, thereby rotating the camshaft 94. In the illustrated embodiment, the camshaft 94 includes a through-hole 96 extending along axis 54 through the camshaft 94. Figure 3 The through-hole 96 is shaped to receive and / or accommodate at least a portion of the helical pinion 82. In the illustrated embodiment, the through-hole 96 extends through the entire length of the camshaft 94, which reduces the weight of the camshaft 94; however, in other embodiments, the through-hole 96 may extend only partially through the camshaft 94.

[0058] refer to Figure 2A and Figure 3 The output shaft 50 is rotatably supported by a first or front bearing 98 and a second or rear bearing 102. The output shaft 50 extends through an opening in the partition wall 113. The helical gears / pinions 82, 86, 90 of the gear assembly 66 can, for example, advantageously provide higher torque capacity and quieter operation than spur gears, but the helical engagement between the helical pinion 82 and the planetary gear 86 generates an axial thrust load on the output shaft 50. Accordingly, the impact wrench 10 includes a hub or bearing cage 106 integrally formed by the end cap 30, which secures the rear bearing 102 both axially (e.g., against forces transmitted along axis 54) and radially (i.e., against forces transmitted in the radial direction of the output shaft 50).

[0059] refer to Figure 3 The fan 58 includes a truncated conical recess 114, and a bearing cage 106 extends into the truncated conical recess 114 such that at least a portion of the bearing cage 106 and at least a portion of the rear bearing 102 overlap with the fan 58 along axis 54. This overlapping arrangement advantageously reduces the axial length of the impact wrench 10.

[0060] Now refer to Figure 2A and Figure 9The front bearing 98 supports the output shaft 50, and since the motor 42 does not require a sensor plate in front of it, the front bearing 98 can be axially recessed into the stator 46. In the illustrated embodiment, the ring gear 90 includes a boss that extends rearward through an opening in the partition wall 113 and forms a bearing support 115 that receives and supports the front bearing 98. In other words, the front bearing 98 is coupled to and supported by the ring gear 90 (e.g., at the outer ring of the front bearing 98) such that a portion of the ring gear 90 extends radially between the housing 14 and the front bearing 98. In this way, the housing 14, the ring gear 90, the front bearing 98, and the output shaft 50 each overlap along axis 54. In other words, at least one line LL (…) can be drawn from the output shaft 50 in a radially outward direction, intersecting the front bearing 98, the stator 46, and the bearing support 115 of the ring gear 90. Figure 9 This overlapping arrangement advantageously reduces the axial length of the impact wrench 10 and is further facilitated by the absence of a sensor plate at the front of the motor 42.

[0061] like Figure 2C As shown, the stator 46 has an outer diameter C1, and the front bearing 98 and rear bearing 102 are separated by a distance C2. More specifically, the distance C2 is measured between the front end of the rear bearing 102 and the rear end of the front bearing 98. In the illustrated embodiment, the distance C2 between bearings 98 and 102 is less than the diameter C1 of the stator 46. In some embodiments, the diameter C1 of the stator 46 may be 50 mm to 70 mm, 50 mm to 60 mm, 55 mm to 60 mm, or 50 mm to 55 mm. Therefore, the motor 42 has a relatively large diameter-to-length ratio, enabling the motor 42 to supply a relatively large amount of power within a relatively compact overall length.

[0062] Now refer to Figure 2A and Figure 3 Describes a drive assembly 70 for the impact wrench 10. The drive assembly 70 includes an anvil 126 extending from the front housing portion 22, to which a tool element (not shown) can be coupled to perform work on a workpiece (e.g., a fastener). The drive assembly 70 is configured to convert a constant rotational force or torque provided by the gear assembly 66 into an impact rotational force or intermittently applied torque to the anvil 126 when the reaction torque on the anvil 126 (e.g., due to engagement between the tool element and the fastener being worked on) exceeds a certain threshold. In the illustrated embodiment of the impact wrench 10, the drive assembly 70 includes a camshaft 94, a hammer 130 supported on the camshaft 94 and axially slidable relative to the camshaft, and the anvil 126. In other words, the hammer 130 is configured to reciprocate axially along the camshaft 94 to apply a rotational impact to the anvil 126 in response to rotation of the camshaft 94.

[0063] A through-hole 96 of the camshaft 94 extends into the anvil 126 (e.g., into a bore, recess, etc.) and leads to an anvil ball 128 positioned within the anvil 126. The camshaft 94 contacts the anvil ball 128 such that the anvil ball 128 provides a wear-resistant contact between the camshaft 94 and the anvil 126 to prevent excessive wear of the anvil. In some embodiments, the anvil ball 128 has a diameter of approximately 5.00 mm to 15.00 mm. In the illustrated embodiment, the anvil ball 128 has a diameter of approximately 10.00 mm.

[0064] Continue to refer to Figure 2A and Figure 3 The drive assembly 70 further includes a spring 134 that directs the hammer 130 toward the front of the impact wrench 10 (e.g., Figure 2A (To the right) bias. In other words, spring 134 biases hammer 130 axially toward anvil 126 along axis 54. Thrust bearing 138 (see also...) Figure 8 The thrust bearing 138 and the thrust washer 142 are positioned between the spring 134 and the hammer 130. The thrust bearing 138 and the thrust washer 142 allow the spring 134 and the camshaft 94 to continue rotating relative to the hammer 130 after each impact when the lug (not shown) on the hammer 130 engages with the corresponding anvil lug 146 and the rotation of the hammer 130 stops momentarily.

[0065] The camshaft 94 further includes cam recesses 150 in which corresponding cam balls 154 are received. The cam balls 154 are driven to engage with the hammer 130 and the movement of the cam balls 154 within the cam recesses 150 allows the hammer 130 to move along the relative axial direction of the camshaft 94 as the hammer lug and anvil lug 146 engage and the camshaft 94 continues to rotate.

[0066] In the illustrated embodiments, continue to refer to Figure 2A and Figure 3 The impact wrench 10 further includes a bushing 158 supported by the housing 14 between the camshaft 94 and the gear assembly 66. The bushing 158 receives a washer or wear ring 162 positioned in a release space or annular groove formed by the rear end portion of the camshaft 94. Just as the gear assembly 66 is supported in a groove 75 formed by the clamshell halves 28a, 28b, the bushing 158 is supported in a groove 166 formed by the clamshell halves 28a, 28b. In other words, each of the first housing portion and the second housing portions 28a, 28b is configured to directly receive a first groove (e.g., groove 75) of the gear assembly 66 and a second groove (e.g., groove 166) of the bushing 158. The bushing 158 is thus positioned within and constrained by the housing 14 to absorb the rearward force generated by the spring 134 against the camshaft 94. In some embodiments, the bushing 158 may abut against the front surface of the ring gear 90.

[0067] While typical impact power tools include camshaft bearings to rotatably support the camshaft within a gearbox, in the illustrated embodiment, a cantilevered planetary gear 86 radially supports the rear end of the camshaft 94, and a bushing 158 axially supports it. This allows for a reduction in the overall length of the impact wrench 10 relative to such typical power tools. Specifically, such bearings in typical impact power tools include balls contained between an inner and outer ring, such that the bearing must be at least as long or as wide as the diameter of the balls. These bearings also require support from a bearing cage, which further increases the depth or length of the bearing assembly and thus the tool. Avoiding such camshaft bearings relative to typical impact power tools also increases the torque-to-length ratio of the impact wrench 10 and reduces its overall weight.

[0068] Now refer to Figures 8 to 10 The bushing 158 includes a plurality of lugs 174. The lugs 174 of the bushing 158 are fitted within recesses 166 of the housing 14 and provide a rigid base for axial loads or forces applied by the spring 134. In the illustrated embodiment, the bushing 158 includes four lugs 174 that are equally positioned around the circumference of the bushing 158 to support the bushing 158 within the housing 14.

[0069] like Figure 8 As further shown, multiple planetary gears 86 are connected by one or more pins 178 (see also...) Figure 11 One or more pins are coupled to the first end 94a of the camshaft 94, extending through an aperture 182 of the bushing 158. In other words, the pin 178 reaches the camshaft 94 from the planetary gear 86 through the aperture 182 of the bushing 158 without contacting the bushing 158. The second end 94b of the camshaft 94 is supported by an anvil 126, which is held in the front housing portion 22 by the anvil bushing 186 (see also...). Figure 2A ).

[0070] Now refer to Figures 8 to 14 The sealing systems 80 and 80' will be described in more detail. For example... Figure 8 The sealing system 80, also known as the sealing assembly 80, shown includes a front portion of a rear sealing portion 190, an intermediate sealing portion 194, and a front sealing portion 198. In some embodiments, each sealing portion 190, 194, 198 is made of a flexible / semi-flexible polymer material (such as rubber, neoprene, silicone, etc.). Typically, the sealing assembly 80 defines a sealing chamber 200. Figure 11 and Figure 12 The sealing chamber contains lubricant between the first end 80a and the second end 80b of the sealing system 80. For example... Figure 11 and Figure 12As shown, chamber 200 is at least partially defined by housing 14 (e.g., motor housing 18) and front housing portion 22.

[0071] For details, please refer to the following: Figure 9 and Figure 10 The first end 80a of the sealing system 80 is typically adjacent to the bushing 158 and the ring gear 90 (e.g., the first end 94a of the camshaft 94), while the second end 80b is positioned adjacent to the anvil 126 and the anvil bushing 186. In the illustrated embodiment, the rear sealing portion 190 at least partially surrounds the ring gear 90 and extends into a groove or recess 204 formed in each of the clamshell halves 28a, 28b. For example, the recess 204 may be partially formed in the first clamshell half 28a and partially formed in the second clamshell half 28b, such that the seam 31 at the contact point between the clamshell halves 28a, 28b is at least sealed closed by the rear sealing portion 190.

[0072] In the illustrated embodiment, at least a portion of the rear seal portion 190, and thus the groove 204, forms an L-shape as it extends through the housing 14. The rear seal portion 190 can be compressed, stretched, and / or otherwise held around the gear assembly 66 to inhibit lubricant migration out of the gear housing 74 (e.g., out of the housing 14, into the motor housing 18, into the handle portion 26, etc.). The upper extension of the rear seal portion 190 can inhibit lubricant leakage from the impact wrench 10 through the clamshell halves 28a, 28b (e.g., through the seam 31), while the lower extension of the rear seal portion 190 can inhibit lubricant migration (e.g., through the seam 31) into the handle portion 26. In some embodiments, the rear seal portion 190 can be fed into or pressed into the groove 204 during assembly of the impact wrench 10.

[0073] In the illustrated embodiment, the L-shaped portion of the rear sealing portion 190 extends around the recess 166 of the gear assembly 66 (e.g., around and / or surrounding the ring gear 90) to further seal the gear assembly 66. Figure 12As shown, the rear seal portion 190 is formed by two separate portions 190a and 190b, each extending around a portion of the ring gear 90 and extending within an L-shaped recess 204. Forming the rear seal portion 190 as two separate portions 190a and 190b facilitates the manufacture (e.g., assembly, forming, etc.) of the impact wrench 10, allowing the rear seal portion 190 to be coupled (e.g., connected, inserted, etc.) to the impact wrench 10 from opposite sides or opposite ends. In other words, the two separate portions 190a and 190b of the rear seal portion 190 are approximately mirror images of each other about axis 54. In the illustrated embodiment, the rear seal portion 190 includes multiple 90-degree deviations, one deviation between the ring gear 90 and the motor housing 18, and another deviation within the recess 204 (e.g., in the L-shaped portion of the recess 204).

[0074] like Figure 10 As best shown, the rear seal portion 190 and the groove 204 can extend into the front end portion 78 and the front housing portion 22. The rear seal portion 190 can further contact (e.g., press, abut, etc.) the intermediate seal portion 194. In the illustrated embodiment, the intermediate seal portion 194 is a flexible (e.g., compressible, stretchable, etc.) O-ring 194. The O-ring 194 can be stretched around the edge 208 of the front housing portion 22. In the illustrated embodiment, as... Figure 10 As shown, edge 208 is positioned to overlap with front end portion 78 of housing 14, and O-ring 194 is compressed and / or positioned between edge 208 and front end portion 78 to seal housing 14 and front housing portion 22 together. In other words, edge 208 and front end portion 78 can overlap each other circumferentially, such that O-ring 194 can contribute to a circumferential seal between motor housing 18 / gear housing 74 and front housing portion 22.

[0075] like Figure 10 and Figure 11 It is emphasized that planetary gear 86 can be fitted onto ring gear (in Figure 10 Within the recess 210 (hidden in the center), lubricant is typically allowed to reach the planetary gear 86, pinion 82, ring gear 90, and pin 178 within the gear assembly 66, but not beyond the ring gear 90. In the illustrated embodiment, an O-ring 194 is positioned between the front housing portion 22 and the motor housing 18 to seal the middle portion of the chamber 200, which is typically located between the first end 80a and the second end 80b of the sealing system 80.

[0076] refer to Figures 9 to 11Each of the fasteners 24 can be threaded into an insert 212 formed in the motor housing 18. In the illustrated embodiment, the insert 212 and the fasteners 24 are made of metal (such as steel, stainless steel, aluminum, and / or the like). In some embodiments, the fasteners 24 are M6 machine screws with hexagonal head caps that can be threaded into the insert 212. When tightened (e.g., threaded), the fasteners 24 pull the motor housing 18 and the front housing portion 22 together to compress or abut against the O-ring 194. Thus, the motor housing 18 and the front housing portion 22 can be coupled together around a portion of the sealing system 80 to prevent lubricant from escaping from, for example, between the motor housing 18 and the front housing portion 22 into the housing 14.

[0077] In the illustrated embodiment, the motor housing 18 and the handle portion 26 comprise a rigid polymer or plastic material, and the front housing portion 22 is metal. Therefore, the sealing system 80 seals the two housings (e.g., the motor housing 18 and the front housing portion 22) formed of different materials together. In the illustrated embodiment, the motor housing 18 and the gear housing 74 are made of a first polymer material, while the front housing portion 22 is made of metal. In some embodiments, the portion of the motor housing 18 supporting the gear assembly 66 (e.g., the gear housing 74) may include additional and / or materials of different compositions (e.g., stronger) to support the gear assembly 66.

[0078] For details, please refer to the following: Figure 11 and Figure 12 The front sealing portion 198 is held between the anvil bushing 186 and the seal retainer 216. For example, the front housing portion 22 may include a plug, insert, ridge, etc., functioning as the seal retainer 216 to prevent movement of the front sealing portion 198 within the front housing portion 22. In the illustrated embodiment, the sealing chamber 200 is defined between the ring gear 90 (e.g., at the rear end 80a) and the seal retainer 216 (e.g., at the front end 80b). In other words, the rear sealing portion 190 inhibits lubricant from migrating axially rearward along the gear assembly 66 and radially out of the housing 14, while the front sealing portion 198 inhibits lubricant from migrating axially forward from the front sealing portion 198 and / or the seal retainer 216. The front sealing portion 198 may further reduce the wobbling or displacement of the anvil 126 to reduce seizing or damage to the anvil 126. Figure 12 As best shown, the front sealing portion 198, O-ring 194, and rear seal 190 may be discontinuous, broken, separate parts and / or the like.

[0079] In the illustrated embodiment, after the clamshell halves 28a, 28b are formed, the sealing assembly 80 is inserted into the shell 14 (e.g., the rear sealing portion 190 and / or the intermediate sealing portion 194) and / or the front shell portion 22 (e.g., the front sealing portion 198). For example, the clamshell halves 28a, 28b can be formed (e.g., blow molding, injection molding, etc.) to have a groove 204 formed therein, and then the rear sealing portion 190 can be secured in the groove 204. Similarly, the front shell portion 22 can be formed (e.g., machined, stamped, etc.), and then the front sealing portion 198 can be inserted into the front shell portion 22 and positioned between the front shell portion 22 and the anvil 126. In some embodiments, at least a portion of the sealing assembly 80 can be integrally formed (e.g., co-molded) with the clamshell halves 28a, 28b.

[0080] refer to Figure 13 and Figure 14 The alternative sealing assembly or sealing system 80' includes an alternative rear sealing portion 190' and an intermediate sealing portion 194', which can be used with the impact wrench 10 in substantially the same manner as the sealing assembly 80. For example, the rear sealing portion 190' can be inserted into / compressed / clamped in a slot or recess 204 formed in the motor housing 18. Although not specifically shown, the rear sealing portion 190' also includes a portion extending around or abutting the ring gear 90, just like the rear sealing portion 190.

[0081] like Figure 14 As shown in the figure, the rear sealing portion 190' can be connected to the first intermediate sealing portion 198a' and the second intermediate sealing portion 198b', which are typically formed to fit between the edge 208 of the front housing portion 22 and the front end portion 78 of the motor housing 18. Figure 10 In the illustrated embodiment, the rear sealing portion 190' and the first intermediate sealing portion 198a' and the second intermediate sealing portion 198b' are discontinuous, such that all three portions meet at the common connector 226. In other embodiments, the rear sealing portion 190' and the first intermediate sealing portion 198a' and the second intermediate sealing portion 198b' may be joined together before or after assembly with the impact wrench 10. In one application of the alternative sealing assembly 80', the common connector 226 may be used to seal at least a portion of the joint 31 of the clamshell halves 28a, 28b and at least a portion of the connection between the front housing portion 22 and the motor housing 18.

[0082] Now for reference Figure 15 and Figure 16According to one example configuration, the impact wrench 10 is dimensionally defined by a first length L1 axially between the end cap 30 and the end of the switch 62. In the illustrated embodiment, the first length L1 may be between about 100.00 mm and about 120.00 mm (e.g., 109.32 mm).

[0083] The impact wrench 10 may include a second length L2 axially defined between the end of the switch 62 and the end of the anvil 126. In the illustrated embodiment, the second length L2 may be between about 60.00 mm and about 80.00 mm (e.g., 69.40 mm).

[0084] The impact wrench 10 may further include a third length L3 axially defined between the end of the anvil 126 and the first end of the ring gear 90 / camshaft 94. In the illustrated embodiment, the third length L3 may be between about 110.00 mm and about 130.00 mm (e.g., 119.823 mm).

[0085] The impact wrench 10 may further include a fourth length L4 axially defined between the rear end of the rear bearing 102 and the rear end of the front bearing 98. In the illustrated embodiment, the fourth length L4 may be between about 40.00 mm and about 60.00 mm (e.g., 49.60 mm).

[0086] The impact wrench 10 may also include a height H3 linearly defined between an end of the switch 62 (e.g., generally at the center of the switch 62) and the bottom of the foot 40. In the illustrated embodiment, this height may be between about 110.00 mm and about 140.00 mm (e.g., 127.19 mm).

[0087] like Figure 16 As shown, when the spring 134 is in an uncompressed or free state / condition, the impact wrench 10 may also include a fifth length L5 axially defined between the rear end of the camshaft 94 and the rear end of the hammer 130. In the illustrated embodiment, the fifth length L5 may be between about 10.00 mm and about 40.00 mm (e.g., 29.1295 mm).

[0088] For example Figure 16 As shown, the stator 46 of the impact wrench 10 may have a dimension D1 that is linearly defined between the ends of the stator 46 (e.g., when cut through the axis 54). In the illustrated embodiment, the dimension D1 may be between about 40.00 mm and about 80.00 mm (e.g., 60.00 mm).

[0089] Therefore, the overall size ratio of the impact wrench 10 can be approximately greater than 2.0, where the size ratio can be defined by the following expression:

[0090] This overall dimension ratio allows for accurate / preferred drive, gear, and motor assemblies (e.g., drive assembly 70, gear assembly 66, motor 42 / motor assembly). The motor 42 and hammer 130 of the impact wrench 10 are compactly located within the housing 14 and closer to the handle portion 26 than typical impact power tools. For example, the combined dimensions of the impact wrench 10 shown (e.g., L1, L2, L3, L4, L5, H3, and D1) are unknown in the art, enabling the impact wrench 10 to possess advanced ergonomics without sacrificing operability (e.g., torque transmission, dimensions, etc.).

[0091] In some embodiments, such as Figure 15 and Figure 16 As shown, the total length OL of the impact wrench 10 can be between about 175.00 mm and about 205.00 mm (e.g., 187.96 mm), and the total height OH of the impact wrench 10 can be between about 225.00 mm and about 255.00 mm (e.g., 234.95 mm). In the illustrated embodiment, the total height OH is 1.25 times the total length OL.

[0092] As described above, the features and dimensions of the impact wrench 10 make it both compact and lightweight. The total weight of the impact wrench shown (excluding battery 34) is between 5.0 and 5.4 pounds in some embodiments, or between 5.0 and 5.2 pounds in others. Furthermore, in some embodiments, the impact wrench 10 is capable of delivering a tightening torque of at least 1,000 ft-lb (ft-pound) to the workpiece, or in other embodiments, at least 1,100 ft-lb. Therefore, the impact wrench 10 is capable of delivering a tightening torque between 185 ft-lb and 220 ft-lb per pound of weight.

[0093] During operation of the impact wrench 10, the operator presses switch 62 to activate motor 42, which continuously drives gear assembly 66 and camshaft 94 via output shaft 50. The helical engagement between helical pinion 82 and planetary gear 86 generates a forward-oriented (e.g., toward drive assembly 70) thrust load along axis 54 of output shaft 50, which is transmitted to rear bearing 102, which is secured by bearing cage 106 and / or housing 14 to resist this thrust load.

[0094] As the camshaft 94 rotates, the cam ball 154 drives the hammer 130 to rotate together with the camshaft 94, and the driving surface of the hammer lug engages the driven surface of the anvil lug 146 to provide impact and rotatably drive the anvil 126 and the tool element. After each impact, the hammer 130 moves or slides backward along the camshaft 94 away from the anvil 126, causing the hammer lug to disengage from the anvil lug 146.

[0095] As the hammer 130 moves backward, the cam ball 154 in the corresponding cam recess 150 in the camshaft 94 moves backward within the cam recess 150. The spring 134 stores part of the backward energy of the hammer 130, thus providing a return mechanism for the hammer 130. After the hammer lug disengages from the corresponding anvil lug 146, as the spring 134 releases its stored energy, the hammer 130 continues to rotate and move forward or slide toward the anvil 126 until the driving surface of the hammer lug re-engages with the driven surface of the anvil lug 146 to induce another impact.

[0096] Figure 17A and Figure 17B Another embodiment of the impact wrench 310 is shown. Figure 17A and Figure 17B The impact wrench 310 is similar to the impact wrench 10 described above. Therefore, the following description focuses on the differences between the impact wrench 310 and the impact wrench 10. Furthermore, features and components of the impact wrench 10 may be incorporated into the impact wrench 310, or vice versa.

[0097] The impact wrench 310 includes a housing 314, a gear assembly 318, and a drive assembly including a camshaft 322, a hammer 326, an anvil 330, and a spring 334 biasing the hammer 326 toward the front of the impact wrench 310. The housing 314 includes a motor housing portion 338 (which may include a first housing portion and a second housing portion, similar to the motor housing portion 38) and an impact box or front housing portion 342 coupled to the motor housing portion 338. The gear assembly 318 includes a ring gear 346 and a plurality of planetary gears 386 meshing with the ring gear 346. The hammer 326 and anvil 330 are disposed within the front housing portion 342 at the front end of the impact wrench 310.

[0098] In the illustrated embodiment, the ring gear 346 includes a flange 347 extending forward from the toothed portion 351 of the ring gear 346. A planetary gear 386 engages with the toothed portion 351, and the rear end of the camshaft 322 is rotatably supported by the flange 347. Thus, the camshaft 322 is partially nested within the ring gear 346. In some embodiments, one or more washers 353, which may be made of a low-friction material (such as Delrin® or nylon), may be provided between the camshaft 322 and the toothed portion 351 to support the rear end of the camshaft 322 against axial forces.

[0099] The impact wrench 310 further includes an intermediate housing 350 disposed between the front housing portion 342 and the ring gear 346. More specifically, the rear end of the intermediate housing 350 is positioned adjacent to the ring gear 346, while the front end of the intermediate housing 350 is positioned adjacent to the front housing portion 342. In the illustrated embodiment, the intermediate housing 350 is cup-shaped and formed of plastic. In other embodiments, the intermediate housing may have other shapes and / or may be formed of different materials.

[0100] like Figure 17B As shown, the intermediate housing 350 receives the rear seal 354 at its rear end and the front seal 358 at its front end. When the impact wrench 310 is assembled, the rear seal 354 is compressed between the rear end of the intermediate housing 350 and the ring gear 346 to form a seal between the intermediate housing 350 and the ring gear 346, while the front seal 358 is compressed between the front end of the intermediate housing 350 and the front housing portion 342 to form a seal between the intermediate housing 350 and the front housing portion 342. Therefore, the intermediate housing 350, the ring gear 346, and the front housing portion or impact chamber 342 at least partially define a sealing chamber in which the gear assembly 318 and the drive assembly are disposed. By sealing between the ring gear 346 and the front housing portion 342, the intermediate housing 350 and the seals 354 and 358 can prevent the migration of grease / lubricant from the chamber into the motor housing portion 338.

[0101] Several features of the present invention are set forth in the appended claims.

Claims

1. A power tool, comprising: The housing includes a first part and a second part joined together at a seam, and an end cap joined to the first part and the second part; A motor, which is mounted within a motor housing portion defined by the first portion and the second portion of the housing, the motor including a shaft configured to rotate about an axis; A gear assembly operatively coupled to the motor, the gear assembly including a ring gear fixed relative to the housing and a plurality of planetary gears meshing with the ring gear; A drive assembly operatively coupled to the gear assembly to receive torque from the shaft via the gear assembly, the drive assembly including... Camshaft, Anvil, and A hammer, configured to reciprocate along the camshaft to apply a rotational impact to the anvil in response to rotation of the camshaft; An impact chamber, connected to the housing opposite to the end cap; characterized in that it further comprises: An intermediate housing is disposed between the ring gear and the impact box, such that the ring gear, the impact box, and the intermediate housing at least partially define a sealed chamber containing the gear assembly and the drive assembly.

2. The power tool as described in claim 1, characterized in that, The housing includes a partition wall extending between the motor and the gear assembly, wherein the shaft extends through an opening in the partition wall, and wherein the ring gear sits against the partition wall.

3. The power tool as described in claim 1, characterized in that, It further includes a lighting assembly comprising a cover connected to the front end of the impact chamber opposite to the intermediate housing, and a plurality of LEDs.

4. The power tool as described in claim 1, characterized in that, The ring gear includes a toothed portion and a flange portion extending from the toothed portion, wherein the flange portion rotatably supports the camshaft.

5. The power tool as described in any one of claims 1-4, characterized in that, The housing and the impact chamber are connected together by one or more fasteners, which are received in inserts fixed within the housing and are made of metallic material.

6. The power tool as described in any one of claims 1-4, characterized in that, It further includes a rear bearing and a front bearing supporting the shaft of the motor, wherein the ring gear includes a boss extending rearward along the axis, and wherein the front bearing is received within and supported by the boss.

7. The power tool as described in claim 6, characterized in that, The motor includes a stator, and wherein the measured distance between the front edge of the rear bearing and the rear edge of the front bearing is less than the outer diameter of the stator.

8. The power tool as described in claim 7, characterized in that, The first part and the second part directly support the stator.

9. The power tool as described in claim 7, characterized in that, The rear bearing is supported by the end cap.

10. The power tool as described in claim 7, characterized in that, The outer diameter of the stator is 50mm to 70mm.

11. The power tool as described in any one of claims 1-4, characterized in that, The housing includes a battery socket, and the power tool further includes a battery detachably connected to the battery socket and configured to power the motor.

12. The power tool as claimed in claim 11, characterized in that, The battery socket includes an elastomeric element that engages with the battery when it is connected to the power tool.

13. A power tool, comprising: The housing includes a first part and a second part joined together at a seam, and an end cap joined to the first part and the second part; A motor, which is mounted within a motor housing portion defined by the first portion and the second portion of the housing, the motor including a shaft configured to rotate about an axis; A gear assembly operatively coupled to the motor, the gear assembly including a ring gear fixed relative to the housing and a plurality of planetary gears meshing with the ring gear; A drive assembly operatively coupled to the gear assembly to receive torque from the shaft via the gear assembly, the drive assembly including... Camshaft, Anvil, and A hammer, configured to reciprocate along the camshaft to apply a rotational impact to the anvil in response to rotation of the camshaft; An impact chamber, connected to the housing opposite to the end cap; characterized in that it further comprises: An intermediate housing is disposed between the ring gear and the impact box, such that the ring gear, the impact box, and the intermediate housing at least partially define a sealed chamber containing the gear assembly and the drive assembly.

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