Electric tool

Abstract

The utility model relates to an electric tool which comprises the following components: a housing which comprises a head housing, a gear box housing, a gear box rear cover and a motor housing which are successively connected from front to back; the motor is located in the motor shell and comprises a motor driving shaft; the speed reduction transmission mechanism comprises a first-stage planetary gear train and a second-stage planetary gear train which are in transmission fit, and the motor driving shaft is in transmission fit with the first-stage planetary gear train; the impact mechanism is positioned in the head shell; wherein the front end and the rear end of the gear box shell are both of an open structure, the speed reduction transmission mechanism is located in the gear box shell, and the gear box rear cover is arranged on an opening in the rear end of the gear box shell in a covering mode. According to the electric tool, the structure of the shell is improved, so that the convenience of assembling the first-stage planetary gear train and the second-stage planetary gear train is improved, and then the assembling efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of power tools, and in particular to a power tool. Background Technology

[0002] Power tools (such as electric wrenches and electric screwdrivers) are tools for tightening and loosening bolts and nuts. They usually use a single-stage planetary gear train to reduce the speed of the motor rotor. If a two-stage planetary gear train is used, the first-stage planetary gear train is assembled first and then the second-stage planetary gear train is assembled when installing the two-stage planetary gear train into the gearbox. Furthermore, when assembling the corresponding planetary gear train, the internal gear ring and planetary gears are installed first, and then the planet carrier is installed. The alignment of the planetary gears with the planetary pins on the planet carrier is difficult and affects the assembly efficiency. Utility Model Content

[0003] Based on the aforementioned deficiencies in the existing technology, the purpose of this utility model is to provide an electric tool that improves the ease of assembling the first-stage planetary gear train and the second-stage planetary gear train by improving the structure of the housing, thereby increasing assembly efficiency.

[0004] Therefore, the present invention provides the following technical solution.

[0005] This utility model provides an electric tool, the electric tool comprising:

[0006] The housing includes, from front to back, a head housing, a gearbox housing, a gearbox rear cover, and a motor housing;

[0007] An electric motor, which is located within the motor housing and includes a motor drive shaft;

[0008] A speed reduction transmission mechanism, comprising a first-stage planetary gear train and a second-stage planetary gear train in a transmission engagement, wherein the motor drive shaft is in a transmission engagement with the first-stage planetary gear train;

[0009] An impact mechanism, located within the head shell;

[0010] The gearbox housing has open structures at both the front and rear ends, the reduction transmission mechanism is located in the gearbox housing, and the gearbox rear cover is provided on the rear open end of the gearbox housing.

[0011] Optionally, the power tool includes screws, and the head housing, gearbox housing, gearbox rear cover, and motor housing are sequentially connected by the screws.

[0012] Optionally, the head housing includes a first mounting hole, the gearbox housing includes a second mounting hole, the gearbox rear cover includes a third mounting hole, and the motor housing includes a fourth mounting hole;

[0013] The screw passes through the first mounting hole, the second mounting hole, the third mounting hole, and the fourth mounting hole in sequence to make a connection.

[0014] Optionally, the outer wall of the head shell is provided with a first protrusion, the gearbox housing includes a main body and a gear mounting cavity surrounded by the main body, the gearbox rear cover includes a cover body and an extension body surrounding the cover body, and the outer wall of the motor housing is provided with a second protrusion; the first protrusion, the main body, the extension body and the second protrusion abut against each other in sequence and are connected by the screw.

[0015] Optionally, the first protrusion, the main body, the extension, and the second protrusion have the same circumferential outer contour shape.

[0016] Optionally, the first-stage planetary gear train includes a first internal gear ring, and the second-stage planetary gear train includes a second internal gear ring;

[0017] The first internal gear ring and the second internal gear ring are engaged in the gear mounting cavity.

[0018] Optionally, the rear end face of the head shell is provided with a first annular protrusion, and the front end face of the gearbox housing is provided with a first annular groove, with the first annular protrusion inserted into the first annular groove.

[0019] Optionally, the rear end face of the gearbox housing is provided with a second annular protrusion, and the front end face of the gearbox rear cover is recessed to form a cavity, with the second annular protrusion engaging with the cavity.

[0020] Optionally, the outer wall of the second annular protrusion is provided with an annular groove, and a sealing ring is engaged in the annular groove to seal the assembly gap between the second annular protrusion and the gearbox rear cover.

[0021] Optionally, the power tool includes a front bearing for supporting the front of the motor drive shaft;

[0022] The rear end face of the gearbox cover is provided with a second annular groove, and the front bearing is engaged with the second annular groove.

[0023] This utility model has the following technical effects:

[0024] This utility model provides an electric tool with an improved housing structure. By setting the gearbox structure as a split structure with the gearbox housing and the gearbox rear cover as two parts that cooperate with each other, during assembly, the second-stage planetary gear train is first installed through the rear opening of the gearbox housing, and then the first-stage planetary gear train is installed through the rear opening of the gearbox housing, and then the gearbox rear cover is installed. In this way, when assembling the corresponding planetary gear train, the planet carrier is installed first and then the planetary gears are installed. The planetary gears can be easily fitted onto the planetary pins of the planet carrier, which facilitates assembly and improves assembly efficiency. Attached Figure Description

[0025] Figure 1 This is a structural cross-sectional view of the power tool of this utility model. Figure 1 ;

[0026] Figure 2 This is a structural cross-sectional view of the power tool of this utility model. Figure 2 ;

[0027] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0028] Figure 4 This is an exploded view of the assembly structure of the housing, screws, and nuts of this utility model;

[0029] Figure 5 This is an exploded view of a partial structure of the power tool of this utility model;

[0030] Figure 6 This is a three-dimensional structural diagram of the gearbox housing of this utility model.

[0031] Explanation of reference numerals in the attached figures

[0032] 100. Power tools;

[0033] 1. Shell;

[0034] 11. Head shell; 111. First mounting hole; 112. First protrusion; 113. First annular protrusion;

[0035] 12. Gearbox housing; 121. Second mounting hole; 122. Main body; 123. Mounting cavity; 124. First annular groove; 125. Second annular protrusion; 1251. Annular groove;

[0036] 13. Gearbox rear cover; 131. Third mounting hole; 132. Cover body; 133. Extension; 134. Second annular groove;

[0037] 14. Motor housing; 141. Fourth mounting hole; 142. Second protrusion;

[0038] 15. Handle housing; 151. Handle;

[0039] 2. Motor; 21. Motor drive shaft;

[0040] 3. Reduction transmission mechanism; 31. First-stage planetary gear train; 311. First internal gear ring; 312. First sun gear; 313. First planetary gear; 314. First planetary carrier; 3141. Carrier body; 3142. First planetary pin; 32. Second-stage planetary gear train; 321. Second internal gear ring; 322. Second sun gear; 323. Second planetary gear; 324. Second planetary carrier; 3241. Second planetary pin;

[0041] 4. Impact mechanism; 41. Impact block; 411. Annular cavity; 42. Spring; 43. Second ball bearing; 44. Washer;

[0042] 51. Screw; 52. Nut;

[0043] 61. Front bearing; 62. Needle roller bearing; 63. Rolling bearing;

[0044] 7. Spindle;

[0045] 8. Output shaft;

[0046] 9. Sealing ring. Detailed Implementation

[0047] To make the technical solution and beneficial effects of this utility model more apparent and understandable, a detailed description is provided below by listing specific embodiments. Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0048] In the description of this utility model, unless otherwise expressly defined, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this utility model and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. That is, they should not be construed as limitations on this utility model.

[0049] In this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating the relative importance of the indicated features or the number of indicated technical features. Therefore, a feature specified as "first" or "second" can explicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two; "several" means at least one; unless otherwise expressly defined.

[0050] In this utility model, unless otherwise explicitly defined, the terms "installation," "connection," "linking," "fixing," and "setting," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral molding; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0051] In this utility model, unless otherwise explicitly defined, the terms "above," "on top of," "above," "over," "below," "below," "below," or "below" for "first feature above second feature" can refer to direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Furthermore, "above," "above," and "over" for "first feature above second feature" can mean the first feature is directly above or diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than the horizontal height of the second feature. Similarly, "below," "below," and "below" for "first feature below second feature" can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0052] In this utility model, "front" and "rear" refer to... Figure 1 and Figure 2 The markings in the text shall prevail.

[0053] The following is based on Figures 1 to 6 This utility model describes the power tool in detail.

[0054] In this embodiment, such as Figures 1 to 5As shown, the power tool 100 includes a housing 1, a motor 2, a reduction transmission mechanism 3, an impact mechanism 4, a spindle 7, and an output shaft 8. The housing 1 includes a head shell 11, a gearbox housing 12, a gearbox rear cover 13, and a motor housing 14 connected sequentially from front to back. The motor 2 is located inside the motor housing 14 and includes a motor drive shaft 21. The reduction transmission mechanism 3 includes a first-stage planetary gear train 31 and a second-stage planetary gear train 32 that are in transmission engagement. The motor drive shaft 21 is in transmission engagement with the first-stage planetary gear train 31, and the speed output by the motor 2 is transmitted sequentially through the first-stage planetary gear train 31 and the second-stage planetary gear train 32. The front and rear ends of the gearbox housing 12 are open structures. The reduction transmission mechanism 3 is located inside the gearbox housing 12, and the gearbox rear cover 13 covers the rear open end of the gearbox housing 12. The gearbox housing 12 and the gearbox rear cover 13 together form a gearbox structure.

[0055] The impact mechanism 4 is located in the head shell 11. The impact mechanism 4 includes an impact block 41, a spring 42, and a first ball (not shown in the figure). The impact block 41 is sleeved on the outer periphery of the main shaft 7. The inner wall of the impact block 41 has an annular cavity 411, and the annular cavity 411 contains a second ball 43. One end of the spring 42 abuts against the main shaft 7, and the other end abuts against the second ball 43, with a washer 44 between them. The inner wall of the impact block 41 has a first guide groove (not shown in the figure), and the outer wall of the main shaft 7 has a second guide groove (not shown in the figure). The first guide groove and the second guide groove together form a guide ball track, and the first ball is movably located in the guide ball track. The main shaft 7 is driven by the second-stage planetary gear train 32. The motor drive shaft 21 drives the main shaft 7 to rotate through the reduction transmission mechanism 3. The main shaft 7 drives the impact block 41 to move through the first ball, and the impact block 41 drives the output shaft 8 to move to output working power.

[0056] By adopting the above technical solution, the gearbox structure is set as a split structure in which the gearbox housing 12 and the gearbox rear cover 13 are matched. In this way, during assembly, the installation is from front to back. First, the output shaft 8, the impact mechanism 4 and the main shaft 7 are installed into the head housing 11. Then, the second-stage planetary gear train 32 is installed from the rear opening of the gearbox housing 12. Next, the first-stage planetary gear train 31 is installed from the rear opening of the gearbox housing 12. Finally, the gearbox rear cover 13 is installed. In this way, when assembling the corresponding planetary gear train, the planet carrier is installed first and then the planetary gears are installed. The planetary gears can be easily fitted onto the planetary pins of the planet carrier, which facilitates assembly and improves assembly efficiency.

[0057] In one implementation, such as Figure 1 and Figure 4 As shown, the power tool 100 includes screws 51, and the head housing 11, gearbox housing 12, gearbox rear cover 13 and motor housing 14 are connected in sequence by screws 51, making the assembly simple and secure.

[0058] Furthermore, such as Figure 1 and Figure 4 As shown, the head housing 11 includes a first mounting hole 111, the gearbox housing 12 includes a second mounting hole 121, the gearbox rear cover 13 includes a third mounting hole 131, and the motor housing 14 includes a fourth mounting hole 141. The screw 51 is relatively long and passes through the first mounting hole 111, the second mounting hole 121, the third mounting hole 131, and the fourth mounting hole 141 in sequence before being screwed to the nut 52, thereby connecting the head housing 11, the gearbox housing 12, the gearbox rear cover 13, and the motor housing 14 in sequence.

[0059] Furthermore, the outer wall of the head shell 11 is provided with a first protrusion 112, and a first mounting hole 111 is provided on the first protrusion 112; the gearbox housing 12 includes a main body 122 and a gear mounting cavity 123 surrounded by the main body 122, and a second mounting hole 121 is provided on the main body 122; the gearbox rear cover 13 includes a cover body 132 and an extension 133 surrounding the cover body 132, and a third mounting hole 131 is provided on the extension 133; the outer wall of the motor housing 14 is provided with a second protrusion 142, and a fourth mounting hole 141 is provided on the second protrusion 142; the first protrusion 112, the main body 122, the extension 133, and the second protrusion 142 abut against each other in sequence and are connected by screws 51. When the head shell 11, gearbox housing 12, gearbox rear cover 13 and motor housing 14 are aligned in sequence, the first protrusion 112, the main body 122, the extension 133 and the second protrusion 142 all protrude outward at least partially to facilitate the assembly of screws 51.

[0060] Furthermore, such as Figure 4 As shown, the first protrusion 112, the main body 122, the extension 133, and the second protrusion 142 have the same circumferential outer contour shape to improve the aesthetics of the outer contour of the shell 1.

[0061] Furthermore, such as Figures 3 to 5 As shown, the first-stage planetary gear train 31 includes a first internal gear ring 311, and the second-stage planetary gear train 32 includes a second internal gear ring 321. The first internal gear ring 311 and the second internal gear ring 321 are engaged in the gear mounting cavity 123. Specifically, the circumferential outer contours of the first internal gear ring 311 and the second internal gear ring 321 are both concave and convex, and the cavity wall of the mounting cavity 123 has a matching concave and convex structure, so that the first internal gear ring 311 and the second internal gear ring 321 are engaged in the gear mounting cavity 123.

[0062] In one implementation, such as Figure 3 and Figure 4As shown, the rear end face of the head shell 11 is provided with a first annular protrusion 113, and the front end face of the gearbox housing 12 is provided with a first annular groove 124. The first annular protrusion 113 is inserted into the first annular groove 124. Thus, when assembling the power tool 100, the gearbox housing 12 and the head shell 11 are first positioned and pre-assembled through the first annular groove 124 and the first annular protrusion 113. Then, the output shaft 8, the impact mechanism 4, and the main shaft 7 are installed into the head shell 11. Then, the second-stage planetary gear train 32 and the first-stage planetary gear train 31 are successively installed into the gearbox housing 12 through the rear end opening. The gearbox rear cover 13 is abutted against the rear end face of the gearbox housing 12, and the motor housing 14 is abutted against the rear end face of the gearbox rear cover 13. The head shell 11, the gearbox housing 12, the gearbox rear cover 13, and the motor housing 14 are connected in sequence by screws 51.

[0063] In one implementation, such as Figure 3 and Figure 6 As shown, the rear end face of the gearbox housing 12 is provided with a second annular protrusion 125, and the front end face of the gearbox rear cover 13 is recessed to form a cavity (not shown in the figure). The second annular protrusion 125 is engaged in the cavity to position and pre-assemble the gearbox rear cover 13 and the gearbox housing 12.

[0064] Furthermore, such as Figure 3 and Figure 6 As shown, the outer wall of the second annular protrusion 125 is provided with an annular groove 1251, and the sealing ring 9 is engaged in the annular groove 1251. The sealing ring 9 seals the assembly gap between the second annular protrusion 125 and the gearbox rear cover 13, preventing the lubricating oil in the gearbox housing 12 from leaking out from the assembly gap between the two.

[0065] In one implementation, such as Figure 3 and Figure 4 As shown, the power tool 100 includes a front bearing 61 for supporting the front of the motor drive shaft 21. The rear end face of the gearbox rear cover 13 is provided with a second annular groove 134, and the front bearing 61 is engaged with the second annular groove 134. The first-stage planetary gear train 31 includes a first internal gear ring 311, a first sun gear 312, four first planetary gears 313, and a first planet carrier 314. The first sun gear 312 is located at the end of the motor drive shaft 21. The first internal gear ring 311, the first sun gear 312, and the first planetary gears 313 are located in the gearbox housing 12. The front end of the motor drive shaft 21 passes through the gearbox rear cover 13 and extends into the gearbox housing 12, so that the first sun gear 312 meshes with the first planetary gears 313.

[0066] In one implementation, such as Figure 3 and Figure 5As shown, the second-stage planetary gear train 32 includes a second internal gear ring 321, a second sun gear 322, four second planetary gears 323, and a second planetary carrier 324. The second sun gear 322 is integrally formed on the first planetary carrier 314. The second internal gear ring 321 is mounted on the inner wall of the housing 1. The second planetary carrier 324 is provided with multiple fifth mounting holes. The second planetary pins 3241 are mounted in the fifth mounting holes. The second planetary gears 323 are mounted on the second planetary pins 3241 of the second planetary carrier 324 and mesh with the second sun gear 322 and the second internal gear ring 321 respectively.

[0067] In one implementation, such as Figure 3 and Figure 5 As shown, the first planetary carrier 314 includes a carrier body 3141 and four first planetary pins 3142. The carrier body 3141 has multiple sixth mounting holes, and the first planetary pins 3142 are mounted in the sixth mounting holes. The first planetary gears 313 are mounted one by one in the first planetary pins 3142. A needle roller bearing 62 is provided between the first planetary gears 313 and the first planetary pins 3142. The second sun gear 322 is located on the side of the carrier body 3141 away from the first planetary pins 3142. Both ends of the carrier body 3141 extend into the first internal gear ring 311 and the second internal gear ring 321, respectively. The carrier body 3141 is accommodated by the internal space of the first internal gear ring 311 and the second internal gear ring 321, which helps to reduce the axial dimension of the power tool 100.

[0068] In one implementation, such as Figure 3 As shown, the second internal gear ring 321 abuts against the front end face of the first internal gear ring 311, which helps to reduce the axial dimension of the power tool 100.

[0069] In one implementation, such as Figure 3 As shown, the second planetary carrier 324 is integrally formed on the end of the main spindle 7. The second planetary carrier 324 is mounted on the inner wall of the gearbox housing 12 by a rolling bearing 63. Since the second planetary carrier 324 is integrally formed on the main spindle 7, the rolling bearing 63 supports the second planetary carrier 324 and also supports the rear end of the main spindle 7.

[0070] In one implementation, such as Figure 2 As shown, housing 1 also includes handle housing 15, which forms handle 151 for the operator to hold.

[0071] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations included in the claims. Various modifications and changes can be made to the above embodiments without departing from the scope of this disclosure. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of this utility model that may not be explicitly described. Therefore, the above embodiments only illustrate several implementations of this utility model and do not limit the scope of protection of this utility model patent.

Claims

1. A power tool, characterized in that, The power tool (100) includes: The housing (1) includes a head housing (11), a gearbox housing (12), a gearbox rear cover (13), and a motor housing (14) connected sequentially from front to back; The motor (2) is located within the motor housing (14) and includes a motor drive shaft (21); The speed reduction transmission mechanism (3) includes a first-stage planetary gear train (31) and a second-stage planetary gear train (32) that are in transmission cooperation, and the motor drive shaft (21) is in transmission cooperation with the first-stage planetary gear train (31); Impact mechanism (4), which is located in the head shell (11); The gearbox housing (12) has open structures at both the front and rear ends. The speed reduction transmission mechanism (3) is located in the gearbox housing (12). The gearbox rear cover (13) is installed over the open rear end of the gearbox housing (12).

2. The power tool according to claim 1, characterized in that, The power tool (100) includes screws (51), and the head shell (11), gearbox housing (12), gearbox rear cover (13) and motor housing (14) are connected in sequence by the screws (51).

3. The power tool according to claim 2, characterized in that, The head shell (11) includes a first mounting hole (111), the gearbox housing (12) includes a second mounting hole (121), the gearbox rear cover (13) includes a third mounting hole (131), and the motor housing (14) includes a fourth mounting hole (141). The screw (51) passes through the first mounting hole (111), the second mounting hole (121), the third mounting hole (131) and the fourth mounting hole (141) in sequence for connection.

4. The power tool according to claim 2, characterized in that, The outer wall of the head shell (11) is provided with a first protrusion (112), the gearbox housing (12) includes a main body (122) and a gear mounting cavity (123) surrounded by the main body (122), the gearbox rear cover (13) includes a cover body (132) and an extension (133) surrounding the cover body (132), and the outer wall of the motor housing (14) is provided with a second protrusion (142); the first protrusion (112), the main body (122), the extension (133) and the second protrusion (142) abut against each other in sequence and are connected by the screw (51).

5. The power tool according to claim 4, characterized in that, The first protrusion (112), the main body (122), the extension (133), and the second protrusion (142) have the same circumferential outer contour shape.

6. The power tool according to claim 4, characterized in that, The first-stage planetary gear train (31) includes a first internal gear ring (311), and the second-stage planetary gear train (32) includes a second internal gear ring (321); The first internal gear ring (311) and the second internal gear ring (321) are engaged in the gear mounting cavity (123).

7. The power tool according to claim 1, characterized in that, The head shell (11) has a first annular protrusion (113) on its rear end face and a first annular groove (124) on its front end face. The first annular protrusion (113) is inserted into the first annular groove (124).

8. The power tool according to claim 1, characterized in that, The rear end face of the gearbox housing (12) is provided with a second annular protrusion (125), and the front end face of the gearbox rear cover (13) is recessed to form a cavity, and the second annular protrusion (125) is engaged in the cavity.

9. The power tool according to claim 8, characterized in that, The outer wall of the second annular protrusion (125) is provided with an annular groove (1251), and a sealing ring (9) is engaged in the annular groove (1251). The sealing ring (9) is used to seal the assembly gap between the second annular protrusion (125) and the gearbox rear cover (13).

10. The power tool according to claim 1, characterized in that, The power tool (100) includes a front bearing (61) for supporting the front of the motor drive shaft (21); The rear end face of the gearbox rear cover (13) is provided with a second annular groove (134), and the front bearing (61) is engaged in the second annular groove (134).

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