Electric tool

Abstract

The utility model relates to an electric tool, which is provided with a motor shaft extending along a first direction, an air cylinder extending perpendicular to the first direction, a first gear meshed with the motor shaft, a second gear coaxial and linked with the first gear, and a third gear sleeved on the air cylinder and meshed with the second gear to drive the air cylinder to rotate, a concave first cavity is formed in the end, facing an air cylinder, of a first gear, a third gear extends into the first cavity from the outer surface of the air cylinder, a motor shaft and the first gear have the meshing length L extending in the first direction, and a second gear and the third gear have the meshing length X extending in the first direction; the projection of the meshing length L and the projection of the meshing length X in the first direction are at least partially overlapped, so that the sizes of the two sets of gears meshed in different directions in the first direction are reduced, the internal structure of the electric tool is compact, the overall size of the electric tool is reduced, and miniaturization of the electric tool is achieved.

Description

[Technical field]

[0001] The utility model relates to the field of electric tools, in particular to an electric tool for performing impact or rotary impact operations on structures such as concrete and masonry. [Background Technology]

[0002] An electric tool, such as an electric hammer, usually has a motor shaft extending in a first direction, a cylinder extending perpendicular to the first direction, a first gear meshing with the motor shaft, a second gear coaxial with and linked to the first gear, and a third gear sleeved on the cylinder and meshing with the second gear to drive the cylinder to rotate. The motor shaft and the first gear have a meshing length extending in the first direction, and the second gear and the third gear have a meshing length extending in the first direction, and the projection lengths of the two meshing lengths in the first direction are superimposed.

[0003] Due to the large working load of heavy electric hammers, high strength requirements are placed on the gear transmission structure. Increasing the size of the gears is often adopted to ensure the strength of the transmission structure. However, increasing the gear size will increase the engagement length, which will lead to a larger overall size of the electric hammer, which is not conducive to the miniaturization of the tool.

[0004] In view of this, it is indeed necessary to provide an improved electric tool to overcome the defects of the prior art. [Utility Model Content]

[0005] In view of the deficiencies in the prior art, the present invention aims to provide an electric tool with a compact structure that can achieve miniaturization of the tool.

[0006] The present invention solves the problems of the prior art by adopting a technical solution: an electric tool comprising a housing, a motor mounted in the housing, a clutch assembly driven by the motor, and an output assembly driven by the clutch assembly, wherein the motor comprises a motor shaft extending in a first direction, the clutch assembly comprises a first gear meshed with the motor shaft, and a second gear coaxial with and linked to the first gear, the output assembly comprises a cylinder extending perpendicular to the first direction and a third gear sleeved on the cylinder, the second gear meshingly connected to the third gear and driving the cylinder to rotate, and when the cylinder is stalled, the first gear and the second gear are disengaged from each other, and the utility model is characterized in that: an end of the first gear facing the cylinder is provided with a first concave cavity, the third gear extends from the outer surface of the cylinder into the first cavity, the motor shaft and the first gear have a meshing length L extending in the first direction, the second gear and the third gear have a meshing length X extending in the first direction, and the meshing length L and the projection of the meshing length X in the first direction at least partially overlap.

[0007] A further improved solution is: the second gear includes a connecting portion extending along the first direction and a second meshing portion formed at one end of the connecting portion, the first gear is rotatably supported on the connecting portion, and the second meshing portion meshes with the third gear.

[0008] A further improved solution is: the clutch assembly includes a clutch disc, and the clutch disc is sleeved on the connecting portion and is non-rotatably connected to the connecting portion.

[0009] A further improved solution is as follows: the first gear has a support portion and a first meshing portion perpendicularly connected to the support portion and extending along the first direction; the first meshing portion is connected to the motor shaft; the support portion and the first meshing portion enclose the first cavity and a second cavity opposite the first cavity; the second cavity at least partially accommodates the clutch disc. A further improved solution is as follows:

[0010] A further improved solution is: the clutch disc includes a clutch disc body at least partially accommodated in the second cavity, a plurality of elastic members and a locking element connected to the clutch disc body, one end of the elastic member abuts against the clutch disc body, and the other end abuts against the locking element.

[0011] A further improved solution is: the inner peripheral wall of the first engaging portion has a plurality of locking grooves and locking protrusions adjacent to the locking grooves, and the elastic member presses the locking element into the locking grooves;

[0012] When the power tool is operating normally, the locking element is locked in the locking groove, and the first gear and the clutch disk rotate synchronously, so that the first gear and the second gear rotate in conjunction with each other;

[0013] When the cylinder is blocked, the locking element compresses the elastic member to move radially inward along the clutch disc body, the locking element slides along the locking groove and passes over the locking protrusion, and the first gear is separated from the rotation of the clutch disc to separate the first gear from the second gear transmission.

[0014] A further improvement is that the second gear and the third gear are configured as bevel gears.

[0015] A further improved solution is: the electric tool includes an eccentric gear, and the eccentric gear is engaged with the motor shaft.

[0016] A further improved solution is: the rotation axis of the eccentric gear is parallel to the rotation axis of the motor shaft, and the eccentric gear and the first gear are respectively engaged with the left and right sides of the motor shaft.

[0017] A further improvement is as follows: the electric tool further comprises an impact assembly housed in the cylinder, the eccentric gear comprises an eccentric disk, and the eccentric disk is connected to the impact assembly to drive the impact assembly to perform reciprocating motion in the cylinder.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The electric tool of the utility model comprises a motor shaft extending in a first direction, a cylinder extending perpendicular to the first direction, a first gear meshing with the motor shaft, a second gear coaxial with and linked to the first gear, and a third gear sleeved on the cylinder and meshing with the second gear to drive the cylinder to rotate. By providing an inwardly concave first cavity at one end of the first gear facing the cylinder, the third gear extends from the outer surface of the cylinder into the first cavity, the motor shaft and the first gear have a meshing length L extending in the first direction, the second gear and the third gear have a meshing length X extending in the first direction, and the projections of the meshing length L and the meshing length X in the first direction at least partially overlap, which reduces the size of the two groups of gears meshing in different directions in the first direction, makes the internal structure of the electric tool compact, and further reduces the overall size of the electric tool, thereby realizing miniaturization of the electric tool. [Brief Description of the Drawings]

[0020] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings:

[0021] Figure 1 is a cross-sectional view of a power tool according to a preferred embodiment of the present utility model;

[0022] Figure 2 yes Figure 1 A partial enlarged schematic diagram of the power tool shown;

[0023] Figure 3 yes Figure 1 A perspective schematic diagram of the first gear and clutch disc of the power tool shown;

[0024] Figure 4 yes Figure 1 A schematic diagram of a clutch disc of the power tool shown;

[0025] Figure 5 yes Figure 1 A partial enlarged view of the gear part of the power tool;

[0026] The meaning of the reference numerals in the figures:

[0027] Power tool 100 housing 10

[0028] Motor 20 Motor shaft 21

[0029] Clutch assembly 30 first gear 31

[0030] First cavity 311 Second cavity 312

[0031] Locking protrusion 3121 Locking groove 3122

[0032] Support portion 313 First engaging portion 314

[0033] Second gear 32 coupling portion 321

[0034] Second meshing portion 322 Clutch disc 33

[0035] Clutch disc body 331 Elastic member 332

[0036] Locking element 333 Output assembly 40

[0037] Cylinder 41 Third gear 42

[0038] Eccentric gear 50 Eccentric disc 51

[0039] Eccentric pin 511 Third engaging portion 52

[0040] Impact assembly 60 connecting rod 61

[0041] Piston 62 Hammer 63

[0042] Impact rod 64 Collet 70 [Specific implementation method]

[0043] The terms used in this utility model are for the purpose of describing specific embodiments only and are not intended to limit the utility model. For example, the terms "upper," "lower," "front," and "rear" used below to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are used only to facilitate the description of the utility model and simplify the description. They do not indicate or imply that the device or element referred to must have a specific orientation or be constructed or operated in a specific orientation. Therefore, they should not be understood as limiting the utility model.

[0044] See also Figures 1 to 5The figure shows a power tool 100 according to a preferred embodiment of the present invention. In this embodiment, the power tool 100 is an electric hammer for drilling or chiseling holes in walls, concrete floors, and the like. The power tool 100 includes a housing 10, a motor 20 disposed within the housing 10, a clutch assembly 30, an output assembly 40, an eccentric gear 50, an impact assembly 60, a chuck 70 extending outward from the front end of the housing 10, and a working head (not shown) retained within the chuck 70. After the power tool 100 is started, the motor 20 drives the output assembly 40 to rotate via the clutch assembly 30, which in turn drives the working head within the chuck 70 to produce a rotational output. The motor 20 drives the impact assembly 60 via the eccentric gear 50 to produce an impact input, which in turn drives the working head within the chuck 70 to produce an impact output.

[0045] See also Figure 1 As shown, the motor 20 includes a motor shaft 21 extending in a first direction, the eccentric gear 50 includes a third meshing portion 52 meshing with the motor shaft 21, and an eccentric disc 51 connected to the impact assembly 60. The rotation axis of the eccentric gear 50 is parallel to the rotation axis of the motor 20. The eccentric disc 51 is integrally provided with an eccentric pin 511. The output assembly 40 includes a cylinder 41 extending perpendicular to the first direction and a third gear 42 sleeved on the cylinder 41. The impact assembly 60 includes an impact rod 64, a hammer 63, a piston 62, and a connecting rod 61, which are sequentially arranged in the cylinder 41 from front to back. The rear end of the connecting rod 61 is sleeved on the eccentric pin 511, and the front end is pivotally connected to the piston 62. The eccentric disc 51 drives the piston 62 to reciprocate through the connecting rod 61. The reciprocating motion of the piston 62 is caused by compressed air driving the hammer 63 to strike the impact rod 64. After the impact, the impact rod 64 strikes the working head in the output direction to achieve impact output.

[0046] See also Figures 1 to 2 As shown, the clutch assembly 30 includes a first gear 31, a second gear 32, and a clutch plate 33. The second gear 32 is coaxially arranged with the first gear 31 and is in tandem with the first gear 31. The second gear 32 meshes with the third gear 42 and drives the cylinder 41 to rotate. When the cylinder 41 is locked, the clutch assembly 30 disengages the first and second gears 31 and 32. The first gear 31 meshes with the motor shaft 21. The first gear 31 meshes with the eccentric gear 50 on the left and right sides of the motor shaft 21, respectively. The projections of the first gear 31 and the eccentric gear 50 overlap in the first direction to ensure that the overall size of the machine is reduced in the first direction.

[0047] See also Figure 2 、 Figure 5As shown, the first gear 31 has a support portion 313 extending toward the second gear 32 and a first meshing portion 314 extending perpendicularly to the support portion 313 and along a first direction. The first meshing portion 314 is in driving connection with the motor shaft 21. The support portion 313 and the first meshing portion 314 enclose a first cavity 311 and a second cavity 312 disposed opposite the first cavity 311. The first cavity 311 is disposed toward the cylinder 41. The third gear 42 extends from the outer surface of the cylinder 41 into the first cavity 311. The motor shaft 21 and the first gear 31 have an engagement length L extending along the first direction, while the second gear 32 and the third gear 42 have an engagement length X extending along the first direction. The meshing length L and the meshing length X at least partially overlap in their projections in the first direction. This reduces the dimensions of the two sets of gears with different meshing directions in the first direction, resulting in a compact internal structure of the power tool 100 and, in turn, a reduction in the overall size of the power tool 100, thus miniaturizing the power tool 100.

[0048] See also Figures 2 to 4 As shown, the second gear 32 includes a connecting portion 321 extending along the first direction and a second meshing portion 322 formed at one end of the connecting portion 321. The support portion 313 is rotatably supported on the connecting portion 321. The second meshing portion 322 meshes with the third gear 42 to drive the cylinder 41 to rotate.

[0049] The clutch disc 33 is sleeved on the coupling portion 321 and non-rotatably connected thereto. The second cavity 312 at least partially accommodates the clutch disc 33. The clutch disc 33 includes a clutch disc body 331 at least partially housed within the second cavity 312, a plurality of elastic members 332 connected to the clutch disc body 331, and a locking element 333. In this embodiment, there are seven elastic members 332 and seven locking elements 333, respectively. One end of the elastic member 332 abuts the clutch disc body 331, and the other end abuts the locking element 333. The inner circumferential wall of the first engaging portion 314 defines a locking groove 3122 and a locking protrusion 3121 adjacent to the locking groove 3122. The locking element 333, at least partially extending out of the clutch disc body 331 due to the elastic force of the elastic member 332, presses the locking element 333 into the locking groove 3122.

[0050] When the power tool 100 is in normal operation, the locking element 333 is retained in the locking groove 3122, and the first gear 31 rotates synchronously with the clutch disk 33 to rotate the first gear 31 and the second gear 32 in a linked manner; when the cylinder 41 is blocked, the locking element 333 compresses the elastic member 332 to move radially inward along the clutch disk body 331, and the locking element 333 slides along the locking groove 3122 and passes over the locking protrusion 3121, separating the rotation of the first gear 31 from the clutch disk 33 to separate the transmission of the first gear 31 and the second gear 32, so that the first gear 31 idles, thereby preventing the hand from twisting due to blocking and causing injury to the operator.

[0051] In this embodiment, the elastic member 332 is configured as a spring, and the second gear 32 and the third gear 42 are configured as bevel gears.

[0052] In this embodiment, a concave first cavity 311 is provided at one end of the first gear 31 facing the cylinder 41, and the third gear 42 extends from the outer surface of the cylinder 41 into the first cavity 311. The motor shaft 21 and the first gear 31 have an engagement length L extending along the first direction, and the second gear 32 and the third gear 42 have an engagement length X extending along the first direction. The engagement length L and the projection of the engagement length X in the first direction at least partially overlap, which reduces the size of the two groups of gears meshing in different directions in the first direction, makes the internal structure of the power tool 100 compact, and thereby reduces the overall size of the power tool 100, thereby realizing the miniaturization of the power tool 100.

[0053] The present invention is not limited to the specific embodiments described above. Persons skilled in the art will readily appreciate that many alternatives to the power tool of the present invention exist without departing from the principles and scope of the present invention. The scope of protection of the present invention shall be determined by the claims.

Claims

1. A power tool comprising a housing, a motor mounted in the housing, a clutch assembly driven by the motor, and an output assembly driven by the clutch assembly, wherein the motor comprises a motor shaft extending in a first direction, the clutch assembly comprises a first gear meshed with the motor shaft, and a second gear coaxial with and linked to the first gear, the output assembly comprises a cylinder extending perpendicular to the first direction and a third gear sleeved on the cylinder, the second gear meshingly connected to the third gear and driving the cylinder to rotate, and when the cylinder is stalled, the first gear and the second gear are disengaged, characterized in that: The first gear is provided with a concave first cavity at one end facing the cylinder, the third gear extends from the outer surface of the cylinder into the first cavity, the motor shaft and the first gear have a meshing length L extending along the first direction, the second gear and the third gear have a meshing length X extending along the first direction, and the meshing length L and the projection of the meshing length X in the first direction at least partially overlap.

2. The electric tool according to claim 1, wherein: The second gear includes a coupling portion extending along the first direction and a second meshing portion formed at one end of the coupling portion. The first gear is rotatably supported on the coupling portion. The second meshing portion meshes with the third gear.

3. The electric tool according to claim 2, wherein: The clutch assembly includes a clutch disc, and the clutch disc is sleeved on the connecting portion in a non-rotatable manner.

4. The electric tool according to claim 3, wherein: The first gear has a supporting portion and a first meshing portion vertically connected to the supporting portion and extending along the first direction. The first meshing portion is connected to the motor shaft. The supporting portion and the first meshing portion surround the first cavity and a second cavity arranged opposite to the first cavity. The second cavity at least partially accommodates the clutch disk.

5. The electric tool according to claim 4, wherein: The clutch disc includes a clutch disc body at least partially accommodated in the second cavity, a plurality of elastic members connected to the clutch disc body, and a locking element. One end of the elastic member abuts against the clutch disc body, and the other end abuts against the locking element.

6. The electric tool according to claim 5, wherein: The inner peripheral wall of the first engaging portion has a plurality of locking grooves and locking protrusions adjacent to the locking grooves, and the elastic member presses the locking element into the locking grooves; When the power tool is operating normally, the locking element is held in the locking groove, and the first gear rotates synchronously with the clutch disk to rotate the first gear and the second gear in conjunction; when the cylinder is blocked, the locking element compresses the elastic part to move radially inward along the clutch disk body, and the locking element slides along the locking groove and passes over the locking protrusion, separating the first gear from the rotation of the clutch disk to separate the transmission of the first gear and the second gear.

7. The electric tool according to claim 1, wherein: The second gear and the third gear are configured as bevel gears.

8. The electric tool according to claim 7, wherein: The electric tool includes an eccentric gear engaged with the motor shaft.

9. The electric tool according to claim 8, wherein: The rotation axis of the eccentric gear is parallel to the rotation axis of the motor shaft, and the eccentric gear and the first gear are respectively engaged with the left and right sides of the motor shaft.

10. The electric tool according to claim 8, wherein: The electric tool further includes an impact assembly housed in the cylinder. The eccentric gear includes an eccentric disk. The eccentric disk is connected to the impact assembly to drive the impact assembly to perform reciprocating motion in the cylinder.

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