CN112276871A

CN112276871A - Hand-held electric tool and method for producing same

Info

Publication number: CN112276871A
Application number: CN202011120909.2A
Authority: CN
Inventors: J·C·巴尔托谢克; J·O·约翰逊; D·F·莱维特; T·S·多尔蒂; M·T·麦克朗; S·C·埃利
Original assignee: Anglo American
Current assignee: Anglo American
Priority date: 2015-06-05
Filing date: 2016-06-03
Publication date: 2021-01-29
Also published as: EP3819083B1; EP3819083A1; EP3302881B1; CN107614204A; EP3302881A1; EP3302881A4; CN107614204B

Abstract

The invention relates to a hand-held electric tool and a manufacturing method thereof. The hand-held power tool includes a housing, a power source, a front end cap, an output shaft, a front housing, and a gear set assembly. The output shaft protrudes from the output end at the front end cap of the housing. The output shaft is also functionally coupled to the power source such that the output shaft rotates in response to activation of the power source when the power source is supplied with electrical power. A gear set assembly is located in the interior space of the front housing and is configured to transfer rotation from the power source to the output spindle. The gear set assembly also includes a ring gear that surrounds a portion of the output shaft and abuts the front end cap of the housing. A set of guide features is provided that is configured to prevent the ring gear from moving relative to the power source and the front housing, or to prevent the front housing from moving relative to the housing.

Description

Hand-held electric tool and method for producing same

Divisional application information

This application is a divisional patent application of the invention patent application entitled "impact tool with ring gear alignment feature" filed on 2016, 3.6.2016, and having application number 201680031488.1.

Related application

This application is related to and claims priority from U.S. patent application No. 15/172,420 entitled "Impact tool with Ring Gear Alignment Features (Impact Tools with Ring Gear Alignment Features)" filed on U.S. provisional patent application No. 62/171,741 filed on 5.6.2015 and U.S. patent application No. 62/171,741 filed on 3.6.2016. The subject matter disclosed in the above-referenced applications is hereby expressly incorporated by reference into this application.

Technical Field

The present invention relates generally to power tools, and more particularly, to impact tools including ring gear alignment features.

Many power tools include a gear assembly configured to convert a rotational force generated by a motor into rotation of an output spindle of the power tool. In such power tools, it is generally desirable to fix the position of the motor and gear assembly relative to each other for proper operation of the power tool. Accordingly, it would be beneficial to have certain features on a power tool include guide features to aid in assembling certain structures and to keep them fixed relative to other structures.

To this end, illustrative embodiments of the present invention provide a hand-held power tool that includes a housing, a power source, a front end cap, an output shaft, a front housing, a gear set assembly, a first set of guide features, and a second set of guide features. The housing supports the power source and includes a front end cap. The output shaft protrudes from an output end at the front end cap of the housing. The output shaft is also functionally coupled to the power source such that the output shaft rotates in response to activation of the power source when the power source is supplied with electrical power. The front housing defines an interior space. The output shaft is located in the internal space of the front housing. The gear set assembly is located in the interior space of the front housing and is configured to transfer rotation from the power source to an output spindle. The gear set assembly also includes a ring gear characterized by an annular ring body having a plurality of teeth on an inner periphery of the annular ring body and a surface on an outer periphery of the annular ring body opposite the inner periphery. The ring gear encircles a portion of the output shaft and abuts the front end cap of the housing. The surface of the outer periphery of the ring gear abuts an interior surface of the front housing. The first set of guide features are located on the interior surface of the front housing and the surface of the outer periphery of the ring gear and are configured to prevent movement of ring gear relative to the power source and the front housing. The second set of guide features is located on the front housing and the end cap of the housing and is configured to prevent movement of the front housing relative to the housing.

The above and other embodiments of the invention may also include: the front case is a hammer case; the impact mechanism is supported in the hammer shell; the front housing is attached to the housing with fasteners; the gear set assembly includes a planetary gear set; the first set of guide features further comprises one or more grooves formed in the interior surface of the front housing and one or more corresponding ridges formed on the surface of the outer periphery of the annular ring body of the ring gear, wherein the one or more grooves are configured to receive the one or more corresponding ridges to prevent movement between the front housing and the ring gear; the first set of guide features having one or more grooves formed in the surface of the outer periphery of the annular ring body of the ring gear and one or more corresponding ridges formed on the interior surface of the front housing, wherein the one or more grooves are configured to receive the one or more corresponding ridges to prevent movement between the front housing and the ring gear; the second set of guide features has one or more corresponding ridges formed on an outer surface of the front endbell of the housing, wherein each of the one or more grooves of the front housing is sized to receive both a corresponding ridge formed on the surface of the outer periphery of the annular ring body of the ring gear and one or more corresponding ridges formed on an outer surface of the front endbell, wherein each of the one or more grooves extends axially along the interior surface of the front housing; a dimension of each of the one or more ridges formed on the surface of the outer periphery of the annular ring body of the ring gear is substantially similar to a dimension of each of the one or more corresponding ridges formed on the outer surface of the front endbell; the inner surface of the front housing defines an inner diameter of the outer periphery of the ring body of the ring gear and an outer diameter of the front endbell; the one or more grooves of the front housing align with the one or more ridges formed on the surface of the outer periphery of the annular ring body of the ring gear and one or more corresponding ridges formed on the outer surface to axially advance the front housing along a central axis toward the housing to engage and secure to the housing; the one or more grooves of the front housing include a flange surface configured to clamp the ring gear against the front endbell when the front housing is secured to the housing; the first set of guide features further comprises one or more ridges formed on the front housing and one or more corresponding grooves formed on the surface of the outer periphery of the ring gear, and the one or more corresponding grooves are formed on the front end cap; the front endbell is configured to surround at least a portion of the ring gear to align and secure the ring gear relative to the power source, wherein the front housing is configured to operatively couple the housing, the front endbell, and the ring gear together; the front end cover includes an annular flange formed in a front end of the front end cover, wherein the annular flange includes an inner surface configured to form a cavity sized to receive a portion of the ring gear; the inner surface of the annular flange of the end cap is operatively coupled to an outer surface of the ring gear to prevent rotation of the ring gear during normal operation; the front housing is configured to be secured to an outer surface of the housing, wherein the front housing includes a housing flange and a gear assembly surface, wherein the housing flange is configured to be operatively coupled to the outer surface of the housing to secure the front housing to a tool housing, and wherein the gear assembly surface is configured to abut the annular flange of the front endbell and the ring gear, whereupon the front housing and the front endbell cooperate to retain the ring gear; the first set of guide features includes the ring gear insert molded to the front endbell, wherein the front housing is operatively coupled to the ring gear, the front endbell, and wherein front housing includes a nose piece located adjacent the output spindle; the front housing includes a tapered section and a flange, wherein the tapered section of the front housing is configured to be operatively coupled to an inner surface of the housing, and wherein the flange is configured to be operatively coupled to an outer surface of the ring gear; the ring gear includes a lip (lip) formed on an inner portion of the ring gear, wherein the lip is configured to cooperate with the front end cap; the ring gear is secured to the front end cap with a securing feature formed on the ring gear, the securing feature filled with a plastic material that holds the ring gear to the front end cap, wherein the securing feature is selected from the group consisting of at least one raised structure and one or more recesses; the ring gear is secured to the front end cap, and wherein the hand held power tool does not include the following securing features: the securing feature includes one or more fastener-engaging fastener guide holes formed in the front end cap and configured to align with corresponding fastener guide holes formed in the ring gear; and a ring gear is molded into a portion of the front housing.

Another illustrative embodiment of the present invention provides a hand-held power tool including a housing, a power source, a front end cap, an output shaft, a front housing, and a gear set assembly. The housing supports a power source and includes the front end cap. The output shaft protrudes from an output end at the front end cap of the housing and is functionally coupled to the power source such that the output shaft rotates in response to activation of the power source when the power source is supplied with electrical power. The front housing defines an interior space, and the output shaft is located in the interior space. The gear set assembly is located in the interior space of the front housing and is configured to transfer rotation from the power source to an output spindle. The gear set assembly also includes a ring gear characterized by an annular ring body having a plurality of teeth on an inner periphery of the annular ring body and a surface on an outer periphery of the annular ring body opposite the inner periphery. The ring gear encircles a portion of the output shaft and abuts the front end cap of the housing. The front housing and the ring gear further include one or more piloting features, each of the one or more piloting features configured to mate the front housing with the ring gear.

The above and other embodiments of the invention may also include: one or more guide features configured to mate the front housing with the front endcap; the one or more guide features include one or more grooves formed in an interior surface of the front housing and one or more corresponding ridges formed on a surface of the outer periphery of the ring gear, wherein the one or more grooves are configured to receive the one or more corresponding ridges to prevent movement between the front housing and the ring gear; the one or more guide features further comprise one or more grooves formed in a surface of the outer periphery of the ring gear, and one or more corresponding ridges formed on the inner surface of the front housing, wherein the one or more grooves are configured to receive the one or more corresponding ridges to prevent movement between the front housing and the ring gear.

Another illustrative embodiment of the present invention provides a hand-held power tool including a housing, a power source, a front end cap, an output shaft, a front housing, and a gear set assembly. The housing supports the power source. The housing contains the front end cap. The output shaft protrudes from an output end at the front end cap of the housing and is functionally coupled to the power source such that the output shaft rotates in response to activation of the power source when the power source is supplied with electrical power. The front housing defines an interior space, and the output shaft is located in the interior space. The gear set assembly is located in the interior space of the front housing and is configured to transfer rotation from the power source to an output spindle. The gear set assembly also includes a ring gear characterized by an annular ring body having a plurality of teeth on an inner periphery of the annular ring body and a surface on an outer periphery of the annular ring body opposite the inner periphery. The ring gear encircles a portion of the output shaft and abuts the front end cap of the housing. The ring gear is insert molded into the front end cap of the housing such that ring gear is restricted from both axial and rotational movement relative to the front end cap.

Drawings

The concepts described in this disclosure are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. For simplicity and clarity of illustration, elements illustrated in the figures are not necessarily drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding or analogous elements.

FIG. 1 is a perspective view of an illustrative power tool;

FIG. 2 is a side elevational view of the power tool of FIG. 1;

FIG. 3 is a front elevational view of the power tool of FIG. 1;

FIG. 4 is a rear elevational view of the power tool of FIG. 1;

FIG. 5 is a cross-sectional view of the motor assembly, hammer case, and ring gear of the power tool of FIG. 1;

FIG. 6 is an enlarged cross-sectional view of the interface between the motor assembly, hammer case and ring gear of the power tool of FIG. 1;

FIG. 7 is a perspective view of the motor assembly, hammer case, and ring gear of the power tool of FIG. 1;

FIG. 8 is a cut-away perspective view of the motor assembly, hammer case and ring gear of the power tool of FIG. 1;

FIG. 9 is a top view of another embodiment of a hammer housing and ring gear that may be used with the power tool of FIG. 1;

FIG. 10 is a top view of another embodiment of a hammer case and ring gear that may be used with the power tool of FIG. 1;

FIG. 11 is a cut-away side elevational view of yet another embodiment of a ring gear alignment feature that may be used with the power tool of FIG. 1;

FIG. 12 is a cut-away side elevational view of another embodiment of a ring gear alignment feature that may be used with the power tool of FIG. 1;

FIG. 13 is a top plan view of the ring gear shown in FIG. 12;

FIG. 14 is a bottom plan view of the ring gear shown in FIG. 12; and is

Fig. 15 is a perspective view of the motor assembly and ring gear shown in fig. 12.

Detailed Description

While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intention to limit the inventive concepts to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Referring now to fig. 1-4, an illustrative power tool 10 is shown. The power tool 10 is illustratively embodied as a cordless power tool. In particular, the power tool 10 is shown in fig. 1 as a pistol-grip cordless power impact tool that includes an impact mechanism in line with the output of the tool 10. However, it should be appreciated that in other embodiments, the power tool 10 may be embodied as another type of impact tool, such as an angled impact tool in which the output of the tool 10 is disposed at an angle (e.g., right angle) to the impact mechanism. It should be appreciated that the power tool 10 may include a local source, such as an electric motor (including, for example, an electric motor or a pneumatic motor).

The illustrative power tool 10 includes a tool housing 12 and a hammer case 14, as shown in fig. 1. The tool housing 12 defines a body 16, a rear cover 18, and a handle 20. The body 16 defines an interior space 22 in which a motor assembly 24 of the tool 10 is positioned. It should be appreciated that the motor assembly 24 may include a power source, such as an electric motor (wired or wireless), an air or other fluid motor. The rear cover 18 is coupled to the body 16 when the tool 10 is assembled to enclose the interior space 22 and define a rear end 26 positioned relative to the hammer case 14 of the tool 10. The rear cover 18 is coupled to the body 16 using fasteners 28 (best seen in fig. 4) that extend through the rear cover 18 and into the motor assembly 24 (see fig. 5, 7 and 8).

In the illustrative embodiment, the handle 20 of the tool housing 12 extends away from the body 16 and is configured to be graspable by a user of the tool 10. A power connection 30 is positioned at an end 32 of the handle 20 opposite the body 16. The power connection 30 may be configured to connect to any power source, such as a battery, a source of motive fluid, or an outlet connected to a power grid. In the illustrative embodiment, the power source 34 of the power tool 10 is a battery attached to the power connection 30.

The tool 10 includes a number of user-selectable input devices that may be embodied as triggers, switches, or knobs configured to allow a user to adjust one or more features of the power tool 10. For example, the handle 20 includes a trigger 36 configured to, among other things, turn an electric motor 38 (see fig. 6) on/off in use of the tool 10. A forward/neutral/reverse ("F/N/R") switch 40 is positioned in the handle 20 proximate the body 16 and the trigger 36. The F/N/R switch 40 is configured to control, among other things, the direction of rotation of the motor 38. The control knob 42 is positioned on the rear cover 18 of the tool 10 (as best seen in fig. 4) and is configured to adjust the operating mode of the power tool 10.

The hammer case 14 is positioned on the body 16 of the tool housing 12 opposite the rear cover 18. The hammer case 14 includes a tool end 44 configured to be coupled to the tool housing 12 and an output end 46 including an aperture 48 through which an output spindle 50 of the tool 10 protrudes. The hammer case 14 defines an interior space 52 in which a gear assembly 54 and an impact mechanism (not shown) are housed. In the illustrative embodiment, the hammer case 14 is removably coupled to the tool housing 12 by one or more fasteners (not shown). In other embodiments, the hammer case 14 may be removably coupled to the tool housing 12 via other mechanisms (e.g., snap fit).

Referring now to fig. 5 and 6, the motor assembly 24 includes an electric motor 38, a front end cap 56, and a rear end cap 58. The electric motor 38 is illustratively embodied as a brushless DC electric motor. The electric motor 38 includes a rotor 60 configured to drive an output shaft 62 to output mechanical power and a stationary component (i.e., stator) 64 extending around the rotor 60. The output shaft 62 is functionally coupled to the output spindle 50 via the gear assembly 54.

The rear end cap 58 is positioned in the interior space 22 to be proximate to the rear cap 18 and the front end cap 56 is positioned such that it is enclosed in the interior space 22 of the tool housing 12 and the interior space 52 of the hammer case 14 (as best seen in FIG. 7). The rotor 60 and stator 64 of the motor 38 are positioned between the two

end caps

56, 58. The front and

rear endbells

56, 58 cooperate to align the rotor 60 and stator 64 such that the rotor 60 and stator 64 extend parallel to a central axis 66 of the motor 38.

The illustrative gear assembly 54 may be embodied as or include a planetary gear set configured to transfer rotation of the output shaft 62 of the motor 38 to the impact mechanism of the tool 10 housed in the hammer case 14. The gear assembly 54 includes a ring gear 68 positioned in the interior space 52 of the hammer case 14. A ring gear 68 surrounds the output shaft 62 and abuts the front end cap 56. The ring gear 68 is formed as an annular ring having an inner surface 70 that includes a plurality of gear teeth 72 and an outer surface 74 configured to abut an inner surface 76 of the hammer case 14.

Referring now to fig. 5-8, the guide features 90 are integrated into the hammer case 14, the front end cap 56, and the ring gear 68. The guide features 90 are configured to align the hammer case 14, the front end cap 56, and the ring gear 68 with one another. The guide features 90 are also configured to prevent the ring gear 68 from rotating relative to the motor assembly 24 and the hammer housing 14.

In the illustrative embodiment, the guide features 90 include one or more grooves 92 formed in the inner surface 76 of the hammer case 14, one or more corresponding ridges 94 formed on the outer surface 74 of the ring gear 68, and one or more corresponding ridges 96 formed on the outer surface 98 of the front end cap 56. Each groove 92 is sized to receive both a corresponding ridge 94 and a corresponding ridge 96. Each groove 92 extends axially from the tool end 44 along the inner surface 76 of the hammer case 14. In the illustrative embodiment, the dimensions of each ridge 94 are about the same as the dimensions of each corresponding ridge 96. Each ridge 94 is located along the outer surface 74 of the ring gear 68 and each ridge 96 is located along an outer surface 98 of the front end cap 56. In the illustrative embodiment, both sets of

ridges

94, 96 are evenly spaced around the outer surface of their respective structures, ring gear 68 and front end cap 56. The hammer case 14 defines an inner diameter that is sized to match the outer diameter of the ring gear 68 and the outer diameter of the front end cap 56. Although the tool 10 is illustratively shown as including four grooves 92, four ridges 94, and four ridges 96, it will be appreciated that in other embodiments, the tool 10 may include any number of grooves 92, corresponding ridges 94, and corresponding ridges 96.

When assembling the tool 10, the user aligns the ridges 94 with the corresponding ridges 96, aligns the grooves 92 of the hammer case 14 with the now aligned

ridges

94, 96, and axially advances the hammer case 14 along the central shaft 66 toward the tool housing 12 until the tool end 44 of the hammer case 14 contacts the tool housing 12. As the hammer case 14 advances along the central axis 66, the grooves 92 first pass over the ridges 94 and then over the ridges 96.

The guide features 90 are configured to fix the ring gear 68 relative to the front end cap 56 such that the ring gear 68 cannot rotate relative to the motor assembly 24. The groove 92 of the hammer case 14 defines a flange surface 100 configured to clamp the ring gear 68 against the front end cap 56 when the hammer case 14 is securely fastened to the tool housing 12.

In some prior art designs, the ring gear 68 is coupled directly to the front end cover 56. In the illustrative embodiment, the position of the ring gear 68 relative to the front end cap 56 is instead fixed by the guide features 90 of the hammer case 14. For example, the hammer case 14 is guided by the front end cap 56, while the hammer case 14 guides the ring gear 68. This embodiment reduces the number of parts of the tool 10 and may reduce the length of the tool 10 by removing the connection between the ring gear 68 and the front end cap 56.

As described above, the guide features 90 may include any number of grooves 92 and

ridges

94, 96. For example, the illustrative guide features 90 of fig. 7 and 8 include four grooves 92 evenly spaced about the inner surface 76 (see fig. 6) of the hammer case 14, four corresponding ridges 94 evenly spaced about the outer surface 74 (see fig. 6) of the ring gear 68, and four corresponding ridges 96 evenly spaced about the outer surface 98 of the front end cap 56. Each groove 92 is configured to mate with both a ridge 94 and a ridge 96. In another illustrative example shown in fig. 9, the guide features 102 include three grooves 104 formed in the hammer housing 14 with three corresponding ridges 106 formed in the ring gear 68 and three corresponding ridges formed in the front end cap 56 (not shown). In another illustrative example shown in fig. 10, the guide features 108 include six grooves 110 formed in the hammer case 14, with six corresponding ridges 112 formed in the ring gear 68 and six corresponding ridges formed in the front end cap 56 (not shown).

Although the guide features 90, 102, 108 have been illustrated and described herein as including

grooves

92, 104, 110 formed in the hammer case 14 and

ridges

94, 96, 106, 112 formed on the ring gear 68 and the front end cap 56, it is contemplated that in other embodiments of the power tool 10, the guide features 90, 102, 108 may take other forms. By way of illustrative example, the guide features may alternatively include ridges formed on the hammer case 14 and corresponding grooves formed in the ring gear 68 and the front end cap 56.

Referring to fig. 11, another embodiment of an alignment feature 200 of the ring gear 268 of the power tool 10 is shown. In this illustrative embodiment, the front end cap 256 is configured to surround the ring gear 268 and thereby align and secure the ring gear 268 relative to the motor assembly 24 of the power tool 10. Additionally, the hammer case 214 is configured to be operatively coupled to the tool housing 12, the front end cap 256, and the ring gear 268. The front end cap 256 includes an annular flange 202 formed in the front end 204 of the front end cap 256. The annular flange 202 includes an inner surface 206 configured to form a cavity 208 sized to receive a portion of the ring gear 268. The inner surface 206 is operatively coupled to the outer surface 210 of the ring gear 268 when the ring gear 268 is assembled in the power tool 10. The front end cap 256 is configured to secure the ring gear 268 and prevent the ring gear 268 from rotating during normal operation of the power tool 10.

In this embodiment of the alignment feature 200, the hammer case 214 is configured to be secured to the outer surface 210 of the tool housing 12. The hammer case 214 includes a housing flange 212 and a gear assembly surface 216 formed in a motor end 218 of the hammer case 214. The housing flange 212 is configured to operatively couple to the outer surface 210 of the tool housing 12 and thereby secure the hammer case 214 to the tool housing 12. Gear assembly surface 216 is configured to abut annular flange 202 of front end cap 256 and ring gear 268 of gear assembly 54 (see also fig. 5). By so doing, the hammer case 214 cooperates with the front end cap 256 to secure the ring gear 268 to the power tool 10.

Referring to fig. 12, another embodiment of an alignment feature 300 of the ring gear 368 of the power tool 10 is shown. The ring gear alignment feature 300 is configured to align the ring gear 368 with the motor assembly 24 (see fig. 11) and allow the power tool 10 to function properly. In this embodiment of the alignment feature 300, the ring gear 368 is insert molded to the front end cover 356 of the motor assembly 24.

Also shown in fig. 12, the hammer case 314 is operatively coupled to the ring gear 368, the front end cap 356, and the tool housing 12 and is configured to seal the interior space 22 of the power tool 10. In the illustrative embodiment, the hammer case 314 includes the nosepiece 302 attached thereto. The hammer case 314 includes a tapered section 304 and a flange 306 formed in the tool end 44 of the hammer case 314. The tapered section 304 of the hammer case 314 is configured to be operatively coupled to the inner surface 310 of the tool housing 12. The flange 306 is configured to be operatively coupled to the

outer surfaces

322, 328 of the ring gear 368.

As shown in fig. 13, ring gear 368 is formed as an annular ring that includes an inner ring surface 318 having a plurality of teeth 320 formed therein and an outer surface 322 having one or more fastener guide holes 324 formed therein. A ring gear 368 extends between the motor end 326 and the other opposite end. A lip 330 is formed in the motor end 326 of the ring gear 368 such that the motor end 326 defines a motor end opening 332 having a smaller diameter than an opposite end opening 334 defined in the opposite end of the ring gear 368. The lip 330 is configured to cooperate with the front end cover 356 to secure the ring gear 368 to the motor assembly 24 (see also fig. 11 and 12). In the illustrative embodiment, the ring gear 368 is secured to the motor assembly 24 by insert molding the ring gear 368 directly into the front end cover 356.

As shown in fig. 14, one or more grooves 336 are formed in the motor end 326 of the ring gear 368 and are configured to secure the ring gear 368 to the front cover 356. During the insert molding process, the thermoplastic enters the groove 336. After the plastic cools, the groove 336 cooperates with the plastic of the front end cover 356 to secure the ring gear 368 to the front end cover 356 such that the ring gear 368 cannot rotate relative to the front end cover 356. It is contemplated that in other embodiments, the groove 336 may be replaced by other raised or recessed features that cooperate with the front end cover 356 to secure the ring gear 368 against rotation relative to the front end cover 356.

As shown in fig. 15, the front end cover 356 includes an outer body 338 sized to receive a ring gear 368. The outer body 338 is configured to be operatively coupled to the outer surface 322 of the ring gear 368 (see fig. 13 and 14). One or more fastener guide holes 340 are formed in the outer body 338. When assembled, fastener guide holes 340 of front end cover 356 are configured to align with corresponding fastener guide holes 324 formed in ring gear 368. The fastener guide holes 324, 340 cooperate with fasteners (not shown) to secure the motor assembly 24 and gear assembly 54 in the tool housing 12. When the fastener guide holes 324, 340 are aligned, the fasteners can pass through the motor assembly 24 and be received by the hammer case 314.

The front end cover 356 also includes an inner body 342 configured to interact with the lip 330 of the ring gear 368 and secure the ring gear 368 to the front end cover 356. During the insert molding process, the plastic of the front end cap 356 is formed around the lip 330, thereby engaging the ring gear 368 to the front end cap 356. In the illustrative embodiment, the insert molding process is accomplished by injecting a thermoplastic into the mold in which the ring gear 368 has been placed. The thermoplastic eventually hardens and thereby forms the front end cap 356.

As best seen in fig. 12-15, the inner body 342 of the front end cover 356 is also configured to guide a cam shaft 372 of an impact mechanism 370 of the tool 10. As shown in fig. 12, the camshaft 372 is integrally formed to include a planetary gear retainer located at a distal end 374 of the camshaft 372. The inner body 342 of the front end cover 356 is formed to include a recessed annular surface 344 that engages the distal end 374 of the camshaft 372 when the tool 10 is assembled. The inner body 342 of the front end cover 356 is also formed to include a wall 346 that extends away from the recessed annular surface 344 (the wall 346 also forms a portion of the inner body 342 that engages and retains the lip 330 of the ring gear 368, as described above). As best seen in fig. 12, when tool 10 is assembled, the inner diameter of wall 346 encircles a portion of the outer diameter of distal end 374 of camshaft 372 such that front end cover 356 guides camshaft 372. This configuration eliminates the need for separate bearings and/or additional components to support the distal end 374 of the camshaft 372, thereby reducing the complexity and overall length of the tool 10.

While certain illustrative embodiments have been described in detail in the drawings and foregoing description, such illustration and description are to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. There are a number of advantages of the present invention that result from the various features of the devices, systems, and methods described herein. It will be noted that alternative embodiments of the apparatus, systems, and methods of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those skilled in the art may readily devise their own implementations of the apparatus, system, and method that incorporate one or more of the features of the present disclosure.

Claims

1. A hand-held power tool, comprising:

a housing supporting a power source;

wherein the housing comprises a front end cap;

an output shaft protruding from an output end at the front end cap of the housing; wherein the output shaft is functionally coupled to the power source such that the output shaft rotates in response to activation of the power source when the power source is supplied with electrical power;

a front housing defining an interior space;

wherein the output shaft is located in the interior space of the front housing; and

a gear set assembly located in the interior space of the front housing;

wherein the gear set assembly is configured to transfer rotation from the power source to an output spindle;

wherein the gear set assembly includes a ring gear characterized by an annular ring body having a plurality of teeth on an inner periphery of the annular ring body and a surface on an outer periphery of the annular ring body opposite the inner periphery;

wherein the ring gear encircles a portion of the output shaft and abuts the front end cap of the housing; and is

Wherein the ring gear is insert molded into the front end cap of the housing such that ring gear is restricted from both axial and rotational movement relative to the front end cap.

2. The hand-held power tool of claim 1, wherein the front housing is coupled to the ring gear and the front endbell, and

wherein the front housing includes a nose piece positioned adjacent the output spindle.

3. The hand-held power tool of claim 1, wherein the front housing includes a tapered section coupled to an interior surface of the housing.

4. The hand-held power tool of claim 1, wherein the front housing includes a flange coupled to the surface on the outer perimeter of the annular ring body opposite the inner perimeter.

5. The hand-held power tool of claim 1, wherein the ring gear includes a lip formed at a first end of the ring gear;

wherein the first end of the ring gear is coupled to the front end cap; and is

Wherein the lip defines a first opening of the ring gear having a first diameter.

6. The hand-held power tool of claim 5, wherein the ring gear includes a second opening defined at a second end of the ring gear opposite the first end of the ring gear;

wherein the second opening comprises a second diameter that is greater than the first diameter.

7. The hand-held power tool of claim 5, wherein the front end cap includes an annular surface and a wall extending distally from the annular surface; and

wherein the wall of the front end cap contacts the lip of the ring gear to limit axial movement of the ring gear.

8. The hand-held power tool of claim 7, further comprising: a camshaft coupled to the ring gear and an output spindle; and is

Wherein the wall of the front end cover surrounds a portion of the camshaft such that the front end cover guides the camshaft.

9. The hand-held power tool of claim 1, wherein the front end cap includes a first fastener guide and the ring gear includes a second fastener guide; and is

Wherein the ring gear is configured to be fixed relative to the housing when the first fastener guide is aligned with the second fastener guide.

10. The hand-held power tool of claim 9, wherein the second fastener guide is formed within the surface on the outer periphery of the annular ring body.

11. The hand-held power tool of claim 1, wherein the ring gear includes a first end coupled to the front end cap;

wherein the first end of the ring gear includes a first securing feature selected from the group consisting of at least one raised structure and at least one recessed structure;

wherein the front end cap includes a second securing feature that is another of the group consisting of at least one raised structure and at least one recessed structure; and

wherein the second securing feature contacts the first securing feature to limit movement of the ring gear.

12. A method of manufacturing the hand-held power tool of claim 1, comprising:

providing a molten thermoplastic material for injection into a mold in which the ring gear has been placed to form the front end cap;

coupling the housing to the front housing; and

coupling the front housing to the ring gear.

13. The method of claim 12, further comprising:

disposing a portion of the molten thermoplastic material adjacent a lip formed at a first end of the ring gear to bond the front end cap to the ring gear.

14. The method of claim 12, further comprising:

disposing a portion of the molten thermoplastic material in contact with a fixed feature of the ring gear;

wherein the securing feature is selected from the group consisting of at least one raised structure and at least one recessed structure.

15. The method of claim 14, wherein the fixed feature is defined at a first end of the ring gear adjacent the power source.

16. A method of manufacturing a hand-held power tool, comprising:

providing a power source, a housing configured to support the power source and including a front end cap, an output spindle, and a gear set assembly configured to transfer rotation from the power source to the output spindle; and

inserting molten thermoplastic material into a mold in which a ring gear of the gear set assembly has been placed to form the front end cap.

17. The method of claim 16, wherein embedding molten thermoplastic material into a mold in which a ring gear of the gearset assembly has been placed to form the front end cap includes:

coupling the front end cover to the ring gear.

18. The method of claim 17, wherein coupling the front end cap to the ring gear includes simultaneously restricting axial and rotational movement of the ring gear relative to the front end cap.

19. The method of claim 16, wherein embedding molten thermoplastic material into a mold in which a ring gear of the gearset assembly has been placed to form the front end cap includes:

disposing a portion of the molten thermoplastic material adjacent a lip formed on the ring gear to bond the front end cap to the ring gear.

20. The method of claim 16, wherein embedding molten thermoplastic material into a mold in which a ring gear of the gearset assembly has been placed to form the front end cap includes:

21. A hand-held power tool, comprising:

a first housing defining an interior space;

a second housing;

a motor assembly received in the interior space, the motor assembly including a power source and a front end cap, the front end cap including a first fastener guide;

a gear assembly coupled to an output shaft coupled to the power source and an output spindle extending through an aperture in an output end of the second housing, the gear assembly including a ring gear having a second fastener guide, the ring gear configured to be fixed relative to the first housing when the first fastener guide is aligned with the second fastener guide; and

a fastener cooperating with the aligned first and second fastener guides to fix a position of each of the motor assembly and the gear assembly, the fastener passing through the motor assembly and being received by the second housing.

22. The hand-held power tool of claim 21, wherein the ring gear is secured to a body portion of the front end cap.

23. The hand-held power tool of claim 22, wherein the body portion includes an inner body that engages with a lip of the ring gear to secure the ring gear to the body portion.

24. The hand-held power tool of claim 22, wherein the ring gear is insert molded into the front end cap.

25. The hand-held power tool of claim 22, wherein the ring gear has one or more raised or recessed features that mate with the front endbell in a manner that prevents rotation of the ring gear relative to the front endbell.

26. The hand-held power tool of claim 22, further comprising an impact mechanism, and wherein the inner body of the body portion comprises a recessed annular surface that engages a distal end of a cam shaft of the impact mechanism.

27. The hand-held power tool of claim 26, wherein the body portion further includes a wall extending distally from the concave annular surface, an inner diameter of the wall being positioned to surround the distal end of the camshaft to guide movement of the camshaft.

28. The hand-held power tool of claim 21, wherein the second fastener guide is formed on an outer periphery of the ring gear.