Power take-off shaft and electric impact tool

Abstract

The present invention relates to a power output shaft and an electric impact tool, wherein the power output shaft comprises: a shaft body, the front end of which is used to extend out of the gearbox front housing of the electric impact tool; a first protrusion connected to the rear end of the shaft body, the first protrusion being used to receive the rotational force output by the striking block of the electric impact tool; a cover structure coaxially connected to the outer periphery of the shaft body; the cover structure is arranged to cover the outer periphery of the first protrusion, and the cover structure is used to be rotatably connected to the inner wall of the gearbox front housing via a shaft sleeve. The power output shaft of the present invention is provided with a cover structure to cover the outer periphery of the first protrusion, and the outer peripheral wall of the cover structure is used to install the shaft sleeve. Without increasing the distance between the front end of the striking block and the rear end of the shaft body, the length of the shaft body can be reduced, thereby making the electric impact tool more compact and smaller in the axial direction.

Description

Technical Field

[0001] The present invention relates to the technical field of electric tools, and in particular to a power output shaft and an electric impact tool. Background Art

[0002] An electric wrench or electric screwdriver mainly includes a motor, a transmission mechanism, an impact mechanism and an output shaft arranged in sequence along the axial direction. The overall volume is relatively large, and it is not convenient to operate the electric wrench or electric screwdriver in a narrow space.

[0003] In existing electric wrenches or electric screwdrivers, the output shaft includes a shaft body and two protruding ears, which receive the impact of the impact mechanism through the two protruding ears. A shaft sleeve is provided between the shaft body of the output shaft and the front housing of the gear box. The shaft body of the output shaft needs to have a certain length to meet the installation requirements of the shaft sleeve, which makes it difficult to shorten the length of the front structure of the electric wrench or electric screwdriver. Summary of the Invention

[0004] In view of the above-mentioned defects in the prior art, an object of the present invention is to provide a power output shaft, which is conducive to making the electric impact tool more compact and smaller in the axial direction.

[0005] To this end, the present invention provides the following technical solutions.

[0006] The present invention provides a power output shaft for an electric impact tool, the power output shaft comprising:

[0007] a shaft body, the front end of which is used to extend out of the front housing of the gear box of the electric impact tool;

[0008] a first protrusion connected to the rear end of the shaft, the first protrusion being used to receive the rotational force output by the striking block of the electric impact tool;

[0009] A cover structure is coaxially connected to the outer periphery of the shaft body; the cover structure is covered on the outer periphery of the first protrusion, and the cover structure is used to be rotatably connected to the inner wall of the gear box front shell through a shaft sleeve.

[0010] Preferably, the rear end of the cover structure is bent outward to form a bent portion, and the bent portion is used to form a clamping cavity with the shaft sleeve, and the clamping cavity is used to clamp a gasket.

[0011] Preferably, the first protrusion is provided with a groove, and the groove is used for the front end of the main shaft of the electric impact tool to be inserted.

[0012] The present invention further provides an electric impact tool, comprising:

[0013] Motor;

[0014] A speed reduction mechanism comprising a gearbox front housing and a transmission gear set;

[0015] The transmission gear set is used to decelerate the rotational force generated by the motor and transmit it to the main shaft;

[0016] an impact mechanism comprising a striking block, the striking block comprising a second protrusion, the second protrusion extending between the first protrusion and the housing structure;

[0017] a power take-off shaft as described above;

[0018] A shaft sleeve is used for rotatably connecting the cover structure and the gear box front housing.

[0019] Preferably, the electric impact tool includes a gasket, an annular protrusion is provided on the inner wall of the gearbox front shell, the gasket is clamped on the outer periphery of the annular protrusion, and the gasket is clamped between the gearbox front shell and the front end surface of the cover structure.

[0020] Preferably, the electric impact tool includes a gasket, the rear end of the cover structure is bent outward to form a bent portion, a clamping cavity is formed between the bent portion and the sleeve, and the gasket is clamped in the clamping cavity.

[0021] Preferably, the front end of the striking block is provided with a yielding inclined surface, and the bending portion is arranged around the yielding inclined surface.

[0022] Preferably, the electric impact tool includes a sealing ring, which is arranged between the outer periphery of the shaft and the inner wall of the gear box front housing.

[0023] Preferably, there are two second protrusions, and the two second protrusions are symmetrically arranged about the axis of the striking block.

[0024] Preferably, the impact mechanism also includes a steel ball and a spring, the main shaft is provided with a concave hole, the striking block is provided with a guide hole connected to the concave hole, the steel ball is embedded in the concave hole, and the two ends of the spring are respectively connected to the striking block and the main shaft.

[0025] The present invention has the following technical effects:

[0026] The present invention provides a power output shaft, which is provided with a cover structure to cover the outer periphery of a first protrusion. In this way, the outer peripheral wall of the cover structure can be used to install a shaft sleeve, replacing the solution of arranging the shaft sleeve between the outer periphery of the shaft body and the front shell of the gear box in traditional electric impact tools. In this way, without increasing the distance between the front end of the striking block and the rear end of the shaft body, the length of the shaft body can also be reduced, so that the electric impact tool is more compact and smaller in the axial direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the three-dimensional structure of the power output shaft in the first embodiment of the present invention;

[0028] Figure 2 A partial structural cross-sectional view of an electric impact tool in a first embodiment of the present invention;

[0029] Figure 3 An exploded view of a partial structure of an electric impact tool in a first embodiment of the present invention;

[0030] Figure 4 A cross-sectional view of the structure of an electric impact tool in a first embodiment of the present invention;

[0031] Figure 5 Schematic diagram of the three-dimensional structure of the power output shaft in the second embodiment of the present invention;

[0032] Figure 6 A partial structural cross-sectional view of an electric impact tool according to a second embodiment of the present invention Figure 1 ;

[0033] Figure 7 A partial structural cross-sectional view of an electric impact tool according to a second embodiment of the present invention Figure 2 ;

[0034] Figure 8 An exploded view of a partial structure of an electric impact tool in a second embodiment of the present invention;

[0035] Figure 9 FIG. 2 is a cross-sectional view of the structure of an electric impact tool according to a second embodiment of the present invention.

[0036] Description of Reference Numerals

[0037] 100. Electric impact tools;

[0038] 1. Power output shaft;

[0039] 11. Shaft; 12. First protrusion; 121. Groove; 13. Housing structure; 131. Bend portion;

[0040] 2. Gearbox front housing; 21. Annular protrusion;

[0041] 3. Shaft sleeve;

[0042] 4. Clamping cavity;

[0043] 5. Gasket;

[0044] 6. Main shaft; 61. Concave hole; 62. Protrusion;

[0045] 7. Impact mechanism; 71. Striking block; 711. Second protrusion; 712. Yielding slope; 713. Guide hole; 72. Steel ball; 73. Spring;

[0046] 8. Sealing ring. DETAILED DESCRIPTION

[0047] To make the technical solutions and beneficial effects of the present invention more clearly understood, the following is a detailed description 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 belongs.

[0048] In the description of the present invention, unless otherwise expressly defined, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of simplifying the description of the present invention, and do not indicate that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and should not be understood as a limitation to the present invention.

[0049] In this disclosure, the terms "first" and "second" are used solely for descriptive clarity and should not be construed as indicating the relative importance of the features indicated or the quantity of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, and "several" means at least one, unless expressly specified otherwise.

[0050] In the present invention, unless otherwise expressly defined, the terms "installed," "connected," "connect," "fixed," and "disposed" should be understood broadly. For example, "connection" can mean fixed connection, removable connection, or integral molding; it can be mechanical or electrical; it can be direct or indirect through an intermediary; it can also refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0051] In the present invention, unless otherwise clearly defined, when a first feature is “on,” “above,” “above,” “above,” “below,” “below,” or “below” a second feature, the first feature and the second feature may be in direct contact, or the first feature and the second feature may be in indirect contact via an intermediate medium. Moreover, when a first feature is “on,” “above,” or “above” a second feature, it may mean that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than the horizontal height of the second feature. When a first feature is “below,” “below,” or “below” a second feature, it may mean that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0052] The "front" and "back" mentioned in the present invention are Figure 2 、 Figure 4 and Figure 9 The markings in the table shall prevail.

[0053] The following is based on Figures 1 to 9 The electric impact tool of the present invention will be described in detail.

[0054] In this embodiment, if Figures 1 to 9 As shown, the electric impact tool 100 includes a motor (not shown in the figure), a reduction mechanism, a main shaft 6, an impact mechanism 7, a power output shaft 1 and a sleeve 3. The reduction mechanism includes a gearbox front housing 2 and a transmission gear set (not shown in the figure). The transmission gear set is located in the gearbox front housing 2, and the power output shaft 1 is rotatably connected to the gearbox front housing 2 through the sleeve 3. In this embodiment, the sleeve 3 can also be replaced with a bearing. The impact mechanism 7 includes a striking block 71, and the striking block 71 includes a second protrusion 711. The second protrusion 711 extends between the first protrusion 12 and the cover structure 13. The motor is used to generate a rotational driving force. The transmission gear set reduces the rotational force of the motor and transmits it to the main shaft 6. The main shaft 6 drives the impact mechanism 7 to generate an impact force. The impact mechanism 7 drives the power output shaft 1 to impact through the striking block 71. Among them, the front end of the power output shaft 1 extends out of the gear box front housing 2, and the power output shaft 1 can be used to connect the sleeve, and the bolts or nuts are loaded and unloaded through the sleeve. Of course, the front end of the power output shaft 1 can also be used to connect the screwdriver rod, and the screws or bolts are loaded and unloaded through the screwdriver rod.

[0055] In this embodiment, if Figures 1 to 3As shown, the power output shaft 1 comprises a shaft body 11, a first protrusion 12, and a housing structure 13. The front end of the shaft body 11 extends outside the gearbox front housing 2 for connection to a socket or screwdriver. The first protrusion 12 is connected to the rear end of the shaft body 11 and is used to receive the rotational force output by the striking block 71 of the electric impact tool. The housing structure 13 is coaxially connected to the outer periphery of the shaft body 11, covering the outer periphery of the first protrusion 12. The housing structure 13 is rotatably connected to the inner wall of the gearbox front housing 2 via the shaft sleeve 3.

[0056] By adopting the above technical solution, the power output shaft 1 is provided with a cover structure 13 which is covered on the periphery of the first protrusion 12. In this way, the outer peripheral wall of the cover structure 13 can be used to install the sleeve 3, replacing the solution of setting the sleeve 3 between the shaft body 11 and the gear box front shell 2 in the traditional electric impact tool. In this way, without increasing the distance between the front end of the striking block 71 and the rear end of the shaft body 11, the length of the shaft body 11 can also be reduced, so that the electric impact tool 100 is more compact and smaller in the axial direction.

[0057] In one embodiment, if Figures 2 to 4As shown, the impact mechanism 7 also includes a steel ball 72 and a spring 73. The main shaft 6 is provided with a recessed hole 61, and the striking block 71 is provided with a guide hole 713. The recessed hole 61 and the guide hole 713 are connected. The steel ball 72 is embedded in the recessed hole 61, and the two ends of the spring 73 are respectively connected to the striking block 71 and the main shaft 6. Specifically, the operating principle of the electric impact tool 100 is similar to that of a conventional impact wrench or impact screwdriver. When the reaction force of the workpiece applied to the power output shaft 1 is less than or equal to a preset value, the motor drives the main shaft 6 to rotate through the transmission gear set at a reduced speed. The main shaft 6 drives the striking block 71 to rotate. Under the interference of the first protrusion 12 and the second protrusion 711, the striking block 71 drives the power output shaft 1 to rotate synchronously. At this time, the electric impact tool 100 is in a rotating state. When the reaction force of the workpiece on the power output shaft 1 is greater than the preset value, the first protrusion 12 of the power output shaft 1 has a greater circumferential resistance to the second protrusion 711 of the striking block 71 during the rotation of the striking block 71, so the power output shaft 1 does not rotate. At this time, under the cooperation of the steel ball 72 and the guide hole 713, the striking block 71 rotates and moves axially backward. At the same time, the striking block 71 that moves backward compresses the spring 73 until the second protrusion 711 of the striking block 71 moves backward to break away from the circumferential contact with the first protrusion 12, and the striking block 71 1 rotates and the spring 73 rebounds, wherein the striking block 71 rotates so that the second protrusion 711 circumferentially hits the first protrusion 12, and the rebound of the spring 73 causes the striking block 71 to axially impact the end face of the power output shaft 1. At this time, the electric impact tool 100 is in an impact state. After the impact is completed, the striking block 71 and the power output shaft 1 are reset to wait for the next impact. The striking block 71 rotates to the next position and impacts the power output shaft 1 again. Finally, the electric impact tool 100 periodically impacts the power output shaft 1 in the rotation direction through the impact mechanism 7.

[0058] In one embodiment, if Figures 2 to 4 As shown, the electric impact tool 100 includes a gasket 5, which is sandwiched between the front gearbox housing 2 and the front end surface of the cover structure 13. An annular protrusion 21 is provided on the inner wall of the front gearbox housing 2, and the gasket 5 is snapped onto the outer periphery of the annular protrusion 21 to secure the gasket 5. Specifically, when the electric impact tool 100 is in operation, the power output shaft 1 undergoes impact motion along its axial direction. The gasket 5 reduces friction between the moving power output shaft 1 and the front gearbox housing 2.

[0059] In another embodiment, Figures 5 to 9As shown, the electric impact tool 100 includes a gasket 5. The rear end of the housing structure 13 is bent outward to form a bent portion 131. The bent portion 131 is used to form a clamping cavity 4 with the sleeve 3. The gasket 5 is sleeved on the outer periphery of the housing structure 13 and clamped in the clamping cavity 4. Specifically, when the electric impact tool 100 is in operation and the power output shaft 1 undergoes impact movement along its axial direction, the gasket 5 located within the clamping cavity 4 can prevent the front end surface of the housing structure 13 from striking the inner wall of the gearbox front housing 2, thereby reducing friction between the power output shaft 1 and the gearbox front housing 2. The gasket 5 also acts as a buffer between the bent portion 131 and the sleeve 3, preventing direct contact between the bent portion 131 and the sleeve 3 and increasing friction between the two. In addition, since the gasket 5 is not fixed by the gearbox front housing 2, the wall thickness of the front end housing of the gearbox front housing 2 can be appropriately reduced (for example, no annular protrusion 21 is required), which facilitates a more compact structure in the axial direction of the electric impact tool 100.

[0060] Furthermore, if Figure 6 As shown, the front end of the striking block 71 is provided with a relief slope 712, and the bending portion 131 is arranged around the relief slope 712. In this way, the setting of the bending portion 131 will not cause the radial size of the electric impact tool 100 to increase, which is conducive to the compact design of the overall structure.

[0061] In one embodiment, if Figure 2 As shown, the first protrusion 12 is provided with a groove 121, into which the front end of the spindle 6 of the electric impact tool is inserted. Specifically, a protrusion 62 is provided at the front end of the spindle 6, which is inserted into the groove 121. The protrusion 62 cooperates with the groove 121 to position and limit the spindle 6 and the power output shaft 1, thereby preventing the power output shaft 1 from shifting during the impact of the striking block 71 on the power output shaft 1.

[0062] In one embodiment, if Figure 3 As shown, there are two second protrusions 711 , and the two second protrusions 711 are symmetrically arranged about the axis of the striking block 71 , which is conducive to the striking block 71 evenly transmitting the force to the power output shaft 1 .

[0063] In one embodiment, if Figure 2 As shown, the electric impact tool 100 includes a sealing ring 8, which is arranged between the outer periphery of the shaft body 11 and the inner wall of the gear box front housing 2 to prevent oil leakage.

[0064] In one embodiment, the transmission gear set includes a sun gear, planetary gears, and an internal ring gear. The sun gear is coaxially connected to the motor shaft, and the planetary gears mesh with the sun gear and the internal ring gear, respectively. The internal ring gear is clipped into the gearbox front housing 2 and secured by a retaining spring. There are three planetary gears, all of which mesh with the sun gear. Thus, when the motor shaft rotates, the sun gear drives the planetary gears, reducing the output speed of the motor shaft via the planetary gears.

[0065] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations of the claims. Various modifications and variations may be made to the above embodiments without departing from the scope of this disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form additional embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments merely illustrate several implementations of the present invention and do not limit the scope of protection of the patent of this invention.

Claims

1. A power output shaft for an electric impact tool, characterized in that: The power output shaft (1) comprises: A shaft (11), the front end of which is used to extend out of the gear box front housing (2) of the electric impact tool; a first protrusion (12) connected to the rear end of the shaft (11), the first protrusion (12) being used to receive the rotational force output by the striking block (71) of the electric impact tool; A cover structure (13) is coaxially connected to the outer periphery of the shaft body (11); the cover structure (13) is arranged to cover the outer periphery of the first protrusion (12), and the cover structure (13) is used to be rotatably connected to the inner wall of the gear box front housing (2) through the shaft sleeve (3).

2. The power take-off shaft according to claim 1, characterized in that: The rear end of the housing structure (13) is bent outward to form a bent portion (131), and the bent portion (131) is used to form a clamping cavity (4) with the shaft sleeve (3), and the clamping cavity (4) is used to clamp a gasket (5).

3. The power take-off shaft according to claim 1, characterized in that: The first protrusion (12) is provided with a groove (121), and the groove (121) is used for inserting the front end of the main shaft (6) of the electric impact tool.

4. An electric impact tool, characterized in that: The electric impact tool (100) comprises: Motor; A speed reduction mechanism comprising a gearbox front housing (2) and a transmission gear set; A main shaft (6), wherein the transmission gear set is used to decelerate the rotational force generated by the motor and transmit it to the main shaft (6); An impact mechanism (7) comprising a striking block (71), wherein the striking block (71) comprises a second protrusion (711), and the second protrusion (711) extends between the first protrusion (12) and the housing structure (13); The power take-off shaft (1) according to any one of claims 1 to 3; A shaft sleeve (3) is used for rotatably connecting the housing structure (13) and the gearbox front housing (2).

5. The electric impact tool according to claim 4, wherein: The electric impact tool (100) includes a gasket (5), an annular protrusion (21) is provided on the inner wall of the gear box front shell (2), the gasket (5) is clamped on the outer periphery of the annular protrusion (21), and the gasket (5) is sandwiched between the front end surface of the gear box front shell (2) and the cover structure (13).

6. The electric impact tool according to claim 4, wherein: The electric impact tool (100) includes a gasket (5), the rear end of the housing structure (13) is bent outward to form a bent portion (131), a clamping cavity (4) is formed between the bent portion (131) and the shaft sleeve (3), and the gasket (5) is clamped in the clamping cavity (4).

7. The electric impact tool according to claim 6, wherein: The front end of the striking block (71) is provided with a yielding inclined surface (712), and the bending portion (131) is arranged around the yielding inclined surface (712).

8. The electric impact tool according to claim 4, wherein: The electric impact tool (100) includes a sealing ring (8) which is arranged between the outer periphery of the shaft body (11) and the inner wall of the gear box front housing (2).

9. The electric impact tool according to claim 4, wherein: There are two second protrusions (711), and the two second protrusions (711) are symmetrically arranged with respect to the axis of the striking block (71).

10. The electric impact tool according to claim 4, wherein The impact mechanism (7) further comprises a steel ball (72) and a spring (73); the main shaft (6) is provided with a concave hole (61); the striking block (71) is provided with a guide hole (713) connected to the concave hole (61); the steel ball (72) is embedded in the concave hole (61); and the two ends of the spring (73) are respectively connected to the striking block (71) and the main shaft (6).

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