Rotary impact tool

Abstract

A rotary impact tool includes a housing, a motor, a gear assembly, and a drive assembly. The motor includes a shaft configured to rotate about an axis. The gear assembly is operably coupled to the motor. The drive assembly is configured to convert a continuous torque from the shaft received through the gear assembly into a periodic rotational impact on the workpiece. The drive assembly includes a camshaft, an anvil, a hammer, and a thrust bearing. The camshaft is operably coupled to the gear assembly. An anvil is positioned adjacent a front end of the camshaft. The hammer is configured to reciprocate along the camshaft to apply a rotational impact to the anvil in response to rotation of the camshaft. The thrust bearing is engaged with the camshaft such that the thrust bearing is configured to at least partially support the camshaft in an axial direction.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 489,932, filed on March 13, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to power tools, and more particularly to rotary impact tools, such as impact wrenches. Background Art

[0004] Rotary impact tools are typically used to provide an impact rotational force to a tool element or workpiece (eg, a fastener) or to intermittently apply torque to tighten or loosen the fastener. Utility Model Content

[0005] In some aspects, the technology described herein relates to a rotary impact tool comprising: a housing; a motor supported within the housing, the motor comprising a shaft configured to rotate about an axis; a gear assembly operably connected to the motor, the gear assembly comprising a ring gear fixed relative to the housing and a plurality of planetary gears meshing with the ring gear; a drive assembly configured to convert continuous torque from the shaft received through the gear assembly into periodic rotational impacts on a workpiece, the drive assembly comprising: a camshaft operably connected to the gear assembly; an anvil positioned adjacent to a front end of the camshaft; and a hammer configured to reciprocate along the camshaft to apply periodic rotational impacts to the anvil in response to rotation of the camshaft; and a thrust bearing engaged with the camshaft such that the thrust bearing is configured to at least partially support the camshaft in an axial direction.

[0006] In some aspects, the technology described herein relates to a rotary impact tool wherein a camshaft includes a rear end, and wherein a thrust bearing engages the camshaft at the rear end of the camshaft.

[0007] In some aspects, the technology described herein relates to a rotary impact tool in which a thrust bearing is disposed along an axis between a ring gear and a camshaft.

[0008] In some aspects, the technology described herein relates to a rotary impact tool in which a thrust bearing is supported within a ring gear against a rear wall of the ring gear.

[0009] In some aspects, the technology described herein relates to a rotary impact tool wherein a thrust bearing includes a first face, a second face, and a plurality of rollers disposed between the first face and the second face.

[0010] In some aspects, the technology described herein relates to a rotary impact tool wherein a shaft includes a helical pinion that engages a planetary gear and is configured to generate a thrust load to a camshaft, and wherein a thrust bearing is configured to support the camshaft against the thrust load.

[0011] In some aspects, the technology described herein relates to a rotary impact tool wherein a camshaft includes a carrier portion that supports a plurality of planetary gears between opposing panels, and wherein a thrust bearing engages the camshaft at one of the opposing panels.

[0012] In some aspects, the technology described herein relates to a rotary impact tool wherein one of the opposing panels is a rearward panel positioned on a rearward side of a planetary gear.

[0013] In some aspects, the technology described herein relates to a rotary impact tool further comprising a rear radial bearing and a front radial bearing rotatably supporting the shaft, wherein the front radial bearing is supported by a ring gear.

[0014] In some aspects, the technology described herein relates to a rotary impact tool comprising: a housing; a motor supported within the housing, the motor comprising a shaft configured to rotate about an axis; a gear assembly operably connected to the motor, the gear assembly comprising a ring gear fixed relative to the housing and a plurality of planetary gears meshing with the ring gear and rotationally engaged with the shaft, such that the motor is configured to drive the planetary gears to rotate about the ring gear via the shaft; a camshaft comprising a carrier portion supporting the planetary gears, such that the camshaft is configured to rotate about the axis with the planetary gears; and a thrust bearing positioned between the camshaft and the ring gear.

[0015] In some aspects, the technology described herein relates to a rotary impact tool in which a thrust bearing is positioned between a rear wall of a ring gear and a rear plate of a carrier portion of a camshaft.

[0016] In some aspects, the technology described herein relates to a rotary impact tool further comprising a hammer coupled to a camshaft and configured to reciprocate along the camshaft, and wherein the thrust bearing is configured to support the camshaft against an axial load generated by the reciprocating motion of the hammer.

[0017] In some aspects, the technology described herein relates to a rotary impact tool wherein the thrust bearing includes a plurality of rollers.

[0018] In some aspects, the technology described herein relates to a rotary impact tool in which a shaft extends through a thrust bearing.

[0019] In some aspects, the technology described herein relates to a rotary impact tool comprising: a housing; a motor supported within the housing, the motor comprising a shaft configured to rotate about an axis; a gear assembly operably coupled to the motor; and a drive assembly configured to convert continuous torque from the shaft received through the gear assembly into periodic rotational impacts on a workpiece, the drive assembly comprising: a camshaft operably coupled to the gear assembly; an anvil; a hammer spring; and a hammer configured to reciprocate along the camshaft to apply a rotational impact to the anvil in response to rotation of the camshaft, wherein movement of the hammer generates an axial load on the camshaft; and a thrust bearing supporting the camshaft so that at least a portion of the axial load on the camshaft is transmitted through the thrust bearing.

[0020] In some aspects, the technology described herein relates to a rotary impact tool wherein the gear assembly includes a ring gear, and wherein a thrust bearing is disposed along an axis between the ring gear and a camshaft.

[0021] In some aspects, the technology described herein relates to a rotary impact tool wherein a thrust bearing includes a first face, a second face, and a plurality of rollers disposed between the first face and the second face.

[0022] In some aspects, the technology described herein relates to a rotary impact tool wherein the gear assembly includes a plurality of planetary gears at least partially engaged with a portion of a shaft, and wherein the camshaft includes a carrier portion that supports the plurality of planetary gears and couples the camshaft for rotation with the plurality of planetary gears.

[0023] In some aspects, the technology described herein relates to a rotary impact tool wherein a carrier portion includes opposing panels and a plurality of planetary gears are positioned between the opposing panels, wherein one end of a hammer spring engages one of the opposing panels, and wherein another of the opposing panels engages a thrust bearing.

[0024] In some aspects, the technology described herein relates to a rotary impact tool further comprising a rear radial bearing and a front radial bearing rotatably supporting a shaft, wherein the shaft extends through the thrust bearing.

[0025] Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a perspective view of an impact tool according to an embodiment of the present disclosure.

[0027] Figure 2 yes Figure 1A cross-sectional view of the impact tool taken along line 2-2.

[0028] Figure 3 yes Figure 1 A three-dimensional view of an impact tool with a first housing portion removed.

[0029] Figure 4 yes Figure 1 A partial exploded view of the impact tool.

[0030] Figure 5 yes Figure 2 An enlarged view of a portion of a cross-sectional view.

[0031] Figure 6 is used for Figure 1 Exploded view of the ring gear, thrust bearing, and camshaft of an impact tool.

[0032] Figure 7 yes Figure 6 Exploded view of a thrust bearing.

[0033] Before explaining any embodiments of the present disclosure in detail, it should be understood that the present disclosure is not limited in its application to the construction details and component arrangements set forth in the following description or shown in the following drawings. The present disclosure is capable of other embodiments and can be practiced or carried out in various ways. DETAILED DESCRIPTION

[0034] Known impact-type power tools may include camshaft bearings that surround the camshaft to radially support the camshaft within the gearbox. Specifically, such bearings of typical impact-type power tools include spheres contained between inner and outer rings, such that the bearings must be at least as long or as wide as the diameter of the spheres. These bearings also require support from a bearing cage, which even further increases the depth or length of the bearing assembly and, therefore, the tool.

[0035] The present disclosure provides, among other things, an impact tool having a camshaft axially supported by a thrust bearing. In some embodiments of the present disclosure, the camshaft may be radially supported by a planetary gear carried by the camshaft and axially supported by a thrust bearing located at the rear end of the camshaft. This may shorten the overall length of the impact tool compared to the known impact tools described above, thereby also increasing the torque-to-length ratio of the impact tool and reducing its overall weight.

[0036] For example, Figure 1An embodiment of a power tool is shown in the form of a rotary impact tool, and more particularly in the form of an impact wrench 10. The impact wrench 10 includes a housing 14 having a motor housing portion 18, an impact box or front housing portion 22 coupled to the motor housing portion 18 (e.g., by a plurality of fasteners 24), and a handle portion 26 extending downwardly 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.

[0037] The illustrated housing 14 also includes an end cap 30 coupled to the motor housing portion 18 opposite the front housing portion 22. The clamshell halves 28a, 28b may be coupled (e.g., fastened) together at an interface or seam 31. In the illustrated embodiment, the end cap 30 is continuous and may be pressed or assembled onto the rear ends of the clamshell halves 28a, 28b. In other words, the end cap 30 may not include two halves such that the end cap 30 may extend over the seam 31. The end cap 30 is coupled to the motor housing portion 18 by a plurality of fasteners. In other embodiments, the end cap 30 may be integrally formed with the motor housing portion 18.

[0038] Reference Figure 1 The impact wrench 10 includes a battery 34 that is removably coupled to a battery receptacle 38 located at a bottom end or foot 40 of the handle portion 26. When the battery 34 is coupled to the battery receptacle 38, the motor 42 ( Figure 2 ) is supported within the motor housing portion 18 and receives power from the battery 34 via connectors, pads, and / or battery terminals supported by the battery receptacle 38. Figure 1 As shown in FIG. 4 , the foot 40 may include one or more vents 44 (eg, air vents, cooling vents, etc.). In the illustrated embodiment, the handle portion 26 of the clamshell halves 28 a , 28 b may be covered or surrounded by a grip portion 45 .

[0039] The battery 34 may be a power tool battery pack commonly used to power power tools such as electric drills, electric saws, etc. (e.g., an 18-volt rechargeable battery pack, or an M18 REDLITHIUM battery pack sold by Milwaukee Electric Tool Corporation). The battery 34 may include lithium-ion (Li-ion) battery cells. In alternative embodiments, the battery pack may have a different chemical composition (e.g., nickel-cadmium (NiCa or NiCad), nickel-hydride, etc.). In the illustrated embodiment, the battery 34 is an 18-volt battery pack. In alternative embodiments, the capacity of the 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 providing power to the impact wrench 10).

[0040] refer to Figure 2 and Figure 3 In the illustrated embodiment, the motor 42 is a brushless direct current ("BLDC") motor having a stator 46 and a rotor 48, and an output shaft 50 is rotatable about an axis 54 relative to the stator 46. In other embodiments, other types of motors may be used. A fan 58 is coupled to the output shaft 50 behind the motor 42 to generate an air flow. A printed circuit board assembly ("PCBA") 60 is positioned in front of the motor 42 and may include a Hall effect sensor for controlling the operation of the motor 42. In some embodiments, the motor 42 may be operable (e.g., controlled) without the use of a Hall effect sensor. Thus, in such embodiments, a printed circuit board adjacent to the front or rear end of the motor 42 is not required, thereby allowing a shorter length required to accommodate the motor 42 in the housing 14.

[0041] The impact wrench 10 also includes a switch 62 (e.g., a trigger switch) supported by the housing 14 that selectively electrically connects the motor 42 (e.g., via suitable control circuitry) to the 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.).

[0042] Continue to refer Figure 2 and Figure 3, the impact wrench 10 further includes a gear assembly 66 driven by the 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 a drive assembly 70. The gear assembly 66 may be configured in any of a number of different ways to provide a 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 gear case or gear housing 74 formed by the housing 14. As will be described in more detail below, the gear assembly 66 and gear housing 74 of the impact wrench 10 further shorten the overall length of the impact wrench 10.

[0043] The gear assembly 66 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 rotationally fixed within the housing 14 (e.g., the gear housing 74). More specifically, the illustrated ring gear 90 includes a plurality of lugs 170 ( Figure 4 ). In the illustrated embodiment, the lugs 170 of the ring gear 90 fit within the grooves formed by the clamshell halves 28a, 28b to support and rotationally constrain the ring gear 90. The rearwardly facing side of the ring gear 90 rests on the partition wall 113 formed by the clamshell halves 28a, 28b. The partition wall 113 separates the gear housing 74 from the motor 42. The forwardly facing side of the ring gear 90 rests on the intermediate housing case 92. The intermediate housing case 92 is disposed between the front housing portion 22 and the ring gear 90. In this way, the intermediate housing case 92 can axially secure the ring gear 90 within the housing 14 of the impact wrench 10. In the illustrated embodiment, the intermediate housing case 92 is cup-shaped and formed of plastic. In other embodiments, the intermediate housing case 92 can have other shapes and / or can be formed of different materials.

[0044] refer to Figure 3 and Figure 4 , the planetary gears 86 are coupled to a camshaft 94 of the drive assembly 70 such that the camshaft 94 functions as a planet carrier. Specifically, the camshaft 94 includes a carrier portion 94a that receives the planetary gears 86. Accordingly, rotation of the output shaft 50 rotates the planetary gears 86, which 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 that extends through the camshaft 94 ( Figure 3 ). The through hole 96 is shaped to accommodate and / or receive 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 only extend partially through the camshaft 94.

[0045] refer to Figure 2 and Figure 3 , the output shaft 50 is rotatably supported by a first or front bearing 98 and a second or rear bearing 102. In the illustrated embodiment, the bearings 98, 102 are radial bearings. The output shaft 50 extends through an opening in the partition wall 113. The helical-type gears / pinions 82, 86, 90 of the gear assembly 66 may advantageously provide higher torque capacity and quieter operation than spur gears, for example, but the helical engagement between the helical pinion 82 and the planetary gears 86 produces an axial thrust load on the output shaft 50. Accordingly, the impact wrench 10 includes a hub or bearing retainer 106 integrally formed by the end cap 30 that secures the rear bearing 102 both axially (e.g., to resist forces transmitted along the axis 54) and radially (i.e., to resist forces transmitted in a radial direction of the output shaft 50).

[0046] refer to Figure 3 , the fan 58 includes a frustoconical recess 114, and the bearing retainer 106 extends into the frustoconical recess 114 such that at least a portion of the bearing retainer 106 and at least a portion of the rear bearing 102 overlap the fan 58 along the axis 54. This overlapping arrangement advantageously reduces the axial length of the impact wrench 10.

[0047] Now refer to Figure 2 and Figure 3 The drive assembly 70 of the impact wrench 10 is described. 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 torque intermittently applied to the anvil 126 when a reaction torque on the anvil 126 (e.g., due to engagement between the tool element and the fastener being performed) 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 periodic rotational impacts to the anvil 126 in response to rotation of the camshaft 94.

[0048] The through hole 96 of the cam shaft 94 extends into the anvil 126 (e.g., into a hole, recess, etc.) and leads to an anvil ball 128 positioned within the anvil 126. The cam shaft 94 contacts the anvil ball 128 so that the anvil ball 128 provides a wear-resistant contact between the cam shaft 94 and the anvil 126 to prevent excessive wear of the anvil. In some embodiments, the diameter of the anvil ball 128 is approximately 5.00 mm to 15.00 mm. In the illustrated embodiment, the diameter of the anvil ball 128 is approximately 10.00 mm.

[0049] Continue to refer Figure 2 and Figure 4 The drive assembly 70 further includes a spring 134 that forces the hammer 130 toward the front of the impact wrench 10 (e.g., Figure 2 In other words, the spring 134 biases the hammer 130 in an axial direction along the axis 54 toward the anvil 126. A forward thrust bearing 138 and a thrust washer 142 are positioned between the spring 134 and the hammer 130. The forward thrust bearing 138 and the thrust washer 142 allow the spring 134 and the camshaft 94 to continue to rotate relative to the hammer 130 after each impact stroke when a lug (not shown) on the hammer 130 engages a corresponding anvil lug 146 and the rotation of the hammer 130 stops momentarily.

[0050] like Figure 4 As best shown in FIG. 1 , the cam shaft 94 further includes cam grooves 150 in which corresponding cam balls 154 are received. The cam balls 154 are in driving engagement with the hammer 130 and movement of the cam balls 154 within the cam grooves 150 allows relative axial movement of the hammer 130 along the cam shaft 94 when the hammer and anvil lugs 146 engage and the cam shaft 94 continues to rotate.

[0051] like Figures 4 to 6 As shown, the impact wrench 10 further includes a camshaft thrust bearing 116. The thrust bearing 116 is supported within the ring gear 90. Specifically, the thrust bearing 116 is shown against the front side of the rear wall 90a of the ring gear 90. The camshaft 94 abuts the thrust bearing 116, opposite the rear wall 90a of the ring gear 90, so that the thrust bearing 116 is located between the rear wall 90a of the ring gear 90 and the rear end of the camshaft 94. In other embodiments, the thrust bearing 116 can support the camshaft 94 within the impact wrench 10 in a different configuration. For example, in some embodiments, the ring gear 90 can be formed as a separate component from the rear gearbox. In such embodiments, the thrust bearing 116 can be sandwiched between the camshaft 94 and the rear gearbox. In another example, the camshaft 94 can be formed without a bracket portion 94a. In such embodiments, the thrust bearing 116 can be sandwiched between the camshaft 94 and a separately formed bracket portion 94a.

[0052] The thrust bearing 116 is configured to receive and support the camshaft 94 (and therefore, the planetary gears 86 carried by the camshaft 94) against axial forces during operation of the impact wrench 10. In this way, the thrust bearing 116 secures the gear assembly 66 against forces transmitted along the axis 54. Figure 7As shown, the thrust bearing 116 includes a front face 118, a rear face 120, and a plurality of rollers 122 disposed between the front face 118 and the rear face 120. In the illustrated embodiment, the front face 118 and the rear face 120 are washers. The output shaft 50 extends through a central aperture in the thrust bearing 116 to engage the planetary gears 86. In some cases, the thrust bearing 116 may not directly contact the rear wall 90a of the ring gear 90 and the camshaft 94, such that during operation of the impact wrench 10, the thrust bearing 116 moves axially back and forth between the rear wall 90a of the ring gear 90 and the camshaft 94. In other embodiments, the thrust bearing 116 may not include washers of the front face 118 and the rear face 120, such that the plurality of rollers 122 are disposed to directly contact another structure (such as, but not limited to, the ring gear 90, the rear gearbox, and the camshaft 94). That is, the front face 118 and the rear face 120 may be formed by another structure, such as, but not limited to, the ring gear 90 , the rear gearbox, and the camshaft 94 .

[0053] refer to Figures 4 to 6 , the planetary gear 86 is coupled to the bracket portion 94a of the camshaft 94 by one or more pins 178 that extend through opposing panels 184 of the bracket portion 94a. In other words, the pins 178 extend through apertures 188 in the opposing panels 184 of the bracket portion 94a so that the planetary gear 86 is supported on the pins 178 between the opposing panels 184. The end of the camshaft 94 opposite the bracket portion 94a is supported by the anvil 126, which is retained in the front housing portion 22 by anvil bushing 192 ( Figure 2 ).

[0054] In operation of the impact wrench 10, reference is made to Figure 2 and Figure 4, the operator depresses the switch 62 to activate the motor 42, which continuously drives the gear assembly 66 and the camshaft 94 via the output shaft 50. The helical engagement between the helical pinion 82 and the planetary gears 86 can generate thrust loads directed forward and rearward (e.g., toward the drive assembly 70) along the axis 54 of the output shaft 50, which are transmitted to the rear bearing 102, which is fixed by the bearing retainer 106 and / or the housing 14 to resist these thrust loads. The thrust bearing 116 disposed between the camshaft and the ring gear 90 also relieves the thrust loads generated by the helical engagement between the helical pinion 82 and the planetary gears 86 to reduce stress on the gear assembly 66 and improve the overall performance of the impact wrench 10. During operation of the impact wrench 10, the spring loading of the hammer 130 can generate additional thrust loads along the axis 54. That is, when the camshaft 94 rotates to load the hammer 130 for impact with the anvil lug 146, the spring 134 can bias the hammer 130 toward the anvil 126. After each impact with the anvil 126, the hammer 130 may retract along the camshaft 94 and compress the spring 134, thereby generating an axial load on the camshaft 94. The thrust bearing 116 bears or absorbs this thrust load to improve the performance of the impact wrench 10. In particular, the thrust bearing 116 provides reduced rotational friction on the camshaft 94 under thrust loads (e.g., from the helical gears 82, 86 and the spring 134) as compared to impact wrenches having camshafts axially supported by sliding surfaces, bushings, etc. The reduced rotational friction provided by the thrust bearing 116 may result in reduced power consumption, extended battery life, and reduced heat generation within the drive assembly 70.

[0055] As the camshaft 94 rotates, the cam ball 154 drives the hammer 130 to rotate with the camshaft 94, and the driving surfaces of the hammer lugs respectively engage the driven surfaces of the anvil lugs 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, so that the hammer lugs are disengaged from the anvil lugs 146.

[0056] As the hammer 130 moves rearwardly, the cam ball 154 located in the corresponding cam groove 150 in the cam shaft 94 moves rearwardly in the cam groove 150. The spring 134 stores some of the rearward energy of the hammer 130, thereby providing a return mechanism for the hammer 130. After the hammer lugs are disengaged from the corresponding anvil lugs 146, as the spring 134 releases its stored energy, the hammer 130 continues to rotate and move or slide forward toward the anvil 126 until the driving surface of the hammer lug reengages the driven surface of the anvil lug 146 to cause another impact.

[0057] Various features of the present disclosure are set forth in the appended claims.

Claims

1. A rotary impact tool comprising: case; a motor supported within the housing, the motor including a shaft configured to rotate about an axis; a gear assembly operably coupled to the motor, the gear assembly comprising a ring gear fixed relative to the housing and a plurality of planet gears meshing with the ring gear; A drive assembly configured to convert continuous torque received from the shaft through the gear assembly into periodic rotational impacts on a workpiece, the drive assembly comprising a camshaft operably coupled to the gear assembly; an anvil positioned adjacent a front end of the cam shaft; as well as a hammer configured to reciprocate along the cam shaft to apply periodic rotary impacts to the anvil in response to rotation of the cam shaft; and Features: A thrust bearing is engaged with the camshaft such that the thrust bearing is configured to at least partially support the camshaft in an axial direction.

2. The rotary impact tool according to claim 1, wherein: The camshaft includes a rear end, and wherein the thrust bearing engages the camshaft at the rear end of the camshaft.

3. The rotary impact tool according to claim 2, wherein: The thrust bearing is disposed between the ring gear and the camshaft along the axis.

4. The rotary impact tool according to claim 3, wherein: The thrust bearing is supported within the ring gear against a rear wall of the ring gear.

5. The rotary impact tool according to claim 1, wherein: The thrust bearing includes a first surface, a second surface, and a plurality of rollers disposed between the first surface and the second surface.

6. The rotary impact tool according to claim 1, wherein: The shaft includes a helical pinion that engages the planetary gears and is configured to generate a thrust load to the camshaft, and wherein the thrust bearing is configured to support the camshaft against the thrust load.

7. The rotary impact tool according to claim 1, wherein: The camshaft includes a carrier portion that supports the plurality of planetary gears between opposing panels, and wherein the thrust bearing engages the camshaft at one of the opposing panels.

8. The rotary impact tool according to claim 7, wherein: One of the opposing panels is a rearward panel positioned on the rearward side of the planet gears.

9. The rotary impact tool according to claim 1, characterized in that Further included are a rear radial bearing and a front radial bearing rotatably supporting the shaft, wherein the front radial bearing is supported by the ring gear.

10. A rotary impact tool comprising: case; a motor supported within the housing, the motor including a shaft configured to rotate about an axis; a gear assembly operably coupled to the motor, the gear assembly comprising a ring gear fixed relative to the housing and a plurality of planet gears meshing with the ring gear and rotationally engaged with the shaft, such that the motor is configured to drive the planet gears to rotate about the ring gear via the shaft; a camshaft including a carrier portion supporting the planetary gears such that the camshaft is configured to rotate with the planetary gears about the axis; as well as Features: A thrust bearing is positioned between the camshaft and the ring gear.

11. The rotary impact tool according to claim 10, wherein: The thrust bearing is positioned between a rear wall of the ring gear and a rear plate of the carrier portion of the camshaft.

12. The rotary impact tool according to claim 10, characterized in that Further included is a hammer coupled to the camshaft and configured to reciprocate along the camshaft, and wherein the thrust bearing is configured to support the camshaft against an axial load generated by the reciprocating motion of the hammer.

13. The rotary impact tool according to claim 10, wherein: The thrust bearing includes a plurality of rollers.

14. The rotary impact tool according to claim 10, wherein: The shaft extends through the thrust bearing.

15. A rotary impact tool comprising: case; a motor supported within the housing, the motor including a shaft configured to rotate about an axis; a gear assembly operably coupled to the motor; as well as A drive assembly configured to convert continuous torque received from the shaft through the gear assembly into periodic rotational impacts on a workpiece, the drive assembly comprising a camshaft operably coupled to the gear assembly; anvil; Hammer spring; as well as a hammer configured to reciprocate along the camshaft to apply a rotary impact to the anvil in response to rotation of the camshaft, wherein movement of the hammer generates an axial load on the camshaft; and Features: A thrust bearing supports the camshaft such that at least a portion of the axial load on the camshaft is transmitted through the thrust bearing.

16. The rotary impact tool according to claim 15, wherein: The gear assembly includes a ring gear, and wherein the thrust bearing is disposed between the ring gear and the camshaft along the axis.

17. The rotary impact tool according to claim 15, wherein: The thrust bearing includes a first surface, a second surface, and a plurality of rollers disposed between the first surface and the second surface.

18. The rotary impact tool according to claim 15, wherein: The gear assembly includes a plurality of planetary gears at least partially engaged with a portion of the shaft, and wherein the camshaft includes a carrier portion that supports the plurality of planetary gears and couples the camshaft for rotation with the plurality of planetary gears.

19. The rotary impact tool according to claim 18, wherein: The carrier portion includes opposing panels and the plurality of planetary gears are positioned between the opposing panels, wherein one end of the hammer spring engages one of the opposing panels, and wherein another of the opposing panels engages the thrust bearing.

20. The rotary impact tool of claim 15, wherein Further included are rear and front radial bearings rotatably supporting the shaft, wherein the shaft extends through the thrust bearing.

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