Electric tool

Abstract

An electric tool, comprising an electric motor shaft (21) extending in a first direction, a cylinder (41) extending perpendicular to the first direction, a first gear (31) meshed with the electric motor shaft (21), a second gear (32) coaxial with and linked to the first gear (31), and a third gear (42) sleeved on the cylinder (41) and meshed with the second gear (32) to drive the cylinder (41) to rotate. By providing a recessed first cavity (311) at the end of the first gear (31) facing the cylinder (41), the third gear (42) extends from the outer surface of the cylinder (41) into the first cavity (311). The electric motor shaft (21) and the first gear (31) have a meshing length L extending in the first direction, and the second gear (32) and the third gear (42) have a meshing length X extending in the first direction; the projections of the meshing length L and the meshing length X in the first direction at least partially overlap.

Description

Power tool [TECHNICAL FIELD]

[0001] The present application relates to the field of power tools, in particular to a power tool for performing impact or rotary impact operation on concrete, masonry and the like structures. [BACKGROUND]

[0002] The power tool, such as an electric hammer, generally has a motor shaft extending along a first direction, a cylinder extending perpendicularly to the first direction, a first gear engaging with the motor shaft, a second gear coaxial with the first gear and connected in linkage with the first gear, and a third gear sleeved on the cylinder and engaging with the second gear to drive the cylinder to rotate, the motor shaft and the first gear having an engaging length extending along the first direction, the second gear and the third gear having an engaging length extending along the first direction, and the projections of the two engaging lengths in the first direction being superimposed.

[0003] Since the heavy electric hammer has a large working load, the strength requirement of the gear transmission structure is high, and the size of the gear is often increased to ensure the strength of the transmission structure, which will increase the engaging length and result in the overall size of the electric hammer being large, which is not conducive to the miniaturization of the tool.

[0004] In view of this, it is necessary to provide an improved power tool to overcome the defects in the prior art. [SUMMARY]

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a power tool with compact structure and miniaturization.

[0006] The technical scheme adopted by the present application to solve the problems of the prior art is: a power tool, comprising a housing, a motor installed in the housing, a clutch assembly driven by the motor, and an output assembly driven by the clutch assembly, the motor comprising a motor shaft extending along a first direction, the clutch assembly comprising a first gear engaging with the motor shaft and a second gear coaxial with the first gear and connected in linkage with the first gear, the output assembly comprising a cylinder extending perpendicularly to the first direction and a third gear sleeved on the cylinder, the second gear engaging with the third gear and driving the cylinder to rotate, when the cylinder is locked, the first gear and the second gear are disconnected, characterized in that: an inner concave first cavity is provided 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 an engaging length L extending along the first direction, the second gear and the third gear have an engaging length X extending along the first direction, and the projections of the engaging length L and the engaging length X in the first direction at least partially overlap.

[0007] A further improvement is as follows: 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 improvement is as follows: the clutch assembly includes a clutch disc, which is sleeved on the connecting part and connected to the connecting part in a non-rotatable manner.

[0009] A further improvement 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 surround a first cavity and a second cavity opposite to the first cavity. The second cavity at least partially accommodates the clutch disc. A further improvement is as follows:

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

[0011] A further improvement is as follows: the inner peripheral wall of the first engaging part has several locking grooves and locking protrusions adjacent to the locking grooves, and the elastic member presses the locking element against the locking groove;

[0012] When the power tool is operating normally, the locking element is engaged in the locking groove, and the first gear rotates synchronously with the clutch disc to link the first gear and the second gear in rotation.

[0013] When the cylinder stalls, the locking element compresses the elastic element and moves radially inward along the clutch disc body. The locking element slides along the locking groove and passes over the locking protrusion, causing the first gear to separate from the rotation of the clutch disc, thereby separating 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 improvement is that the power tool includes an eccentric gear, which meshes with the motor shaft.

[0016] A further improvement is that the rotation axis of the eccentric gear is parallel to the rotation axis of the motor shaft, and the eccentric gear meshes with the first gear on the left and right sides of the motor shaft, respectively.

[0017] A further improvement is as follows: the power tool further includes an impact assembly housed within the cylinder, the eccentric gear includes an eccentric disc, the eccentric disc is connected to the impact assembly, so as to drive the impact assembly to reciprocate within the cylinder.

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

[0019] The power tool of the present invention has a motor shaft extending along 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 a recessed 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 along the first direction, and the second gear and the third gear have a meshing length X extending along the first direction. The projections of the meshing length L and the meshing length X in the first direction at least partially overlap. This reduces the size of the two sets of gears meshing in different directions in the first direction, making the internal structure of the power tool compact, thereby reducing the overall size of the power tool and achieving miniaturization of the power tool. [Image Description]

[0020] The specific embodiments of the present invention will be 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 invention;

[0022] Figure 2 is a partially enlarged schematic diagram of the power tool A shown in Figure 1;

[0023] Figure 3 is a three-dimensional schematic diagram of the first gear and clutch disc of the power tool shown in Figure 1;

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

[0025] Figure 5 is a partial enlarged view of the gear part of the power tool in Figure 1;

[0026] Meaning of reference numerals in the figures: Power tool 100, Housing 10, Motor 20, Motor shaft 21, Clutch assembly 30, First gear 31, First cavity 311, Second cavity 312, Locking protrusion 3121, Locking groove 3122, Support part 313, First meshing part 314, Second gear 32, Connecting part 321, Second meshing part 322, Clutch disc 33, Clutch disc body 331, Elastic element 332, Locking element 333, Output assembly 40, Cylinder 41, Third gear 42, Eccentric gear 50, Eccentric disc 51, Eccentric pin 511, Third meshing part 52, Impact assembly 60, Connecting rod 61, Piston 62, Hammer 63, Impact rod 64, Chuck 70 [Detailed Implementation]

[0027] The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, terms such as "upper," "lower," "front," and "rear" that indicate orientation or positional relationship are based solely on the orientation or positional relationship shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device / element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0028] Please refer to Figures 1 to 5, which illustrate a preferred embodiment of the power tool 100 of the present invention. In this embodiment, the power tool 100 is an electric hammer for drilling or chiseling on walls, cement floors, and other surfaces. 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) fixed 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, and the output assembly 40 drives the working head within the chuck 70 to rotate and output. The motor 20 drives the impact assembly 60 via the eccentric gear 50 to input an impact, and the impact assembly 60 drives the working head within the chuck 70 to output an impact.

[0029] Please refer to Figure 1. The motor 20 includes a motor shaft 21 extending along a first direction. The eccentric gear 50 includes a third meshing part 52 meshing with the motor shaft 21 and an eccentric disk 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. An eccentric pin 511 is integrally provided on the eccentric disk 51. 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 arranged sequentially from front to back in the cylinder 41. 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 disk 51 drives the piston 62 to reciprocate through the connecting rod 61. The reciprocating motion of the piston 62 compresses air to drive the hammer 63 to strike the impact rod 64. After being impacted, the impact rod 64 strikes the working head along the output direction to achieve impact output.

[0030] Please refer to Figures 1 and 2. The clutch assembly 30 includes a first gear 31, a second gear 32, and a clutch disc 33. The second gear 32 is coaxially arranged with and linked to 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 stalls, the first gear 31 and the second gear 32 disengage. The first gear 31 meshes with the motor shaft 21. The first gear 31 and the eccentric gear 50 mesh on the left and right sides of the motor shaft 21 respectively, and their projections overlap in the first direction to ensure that the overall size of the machine is reduced in the first direction.

[0031] Please refer to Figures 2 and 5. The first gear 31 has a support portion 313 extending toward the second gear 32 and a first meshing portion 314 extending perpendicular to the support portion 313 and along a first direction. The first meshing portion 314 is connected to the motor shaft 21. The support portion 313 and the first meshing portion 314 surround a first cavity 311 and a second cavity 312 opposite to 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 a meshing length L extending along the first direction. The second gear 32 and the third gear 42 have a meshing length X extending along the first direction. The projections of the meshing length L and the meshing length X in the first direction at least partially overlap, thereby reducing the size of the two sets of gears with different meshing directions in the first direction. The internal structure of the power tool 100 is compact, which in turn reduces the overall size of the power tool 100, achieving miniaturization of the power tool 100.

[0032] Please refer to Figures 2 to 4. The second gear 32 includes a connecting portion 321 extending along a 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.

[0033] The clutch disc 33 is sleeved on the connecting portion 321 and is non-rotatably connected to the connecting portion 321. 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 accommodated in 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. One end of the elastic member 332 abuts against the clutch disc body 331, and the other end abuts against the locking element 333. The inner peripheral wall of the first engagement portion 314 has a locking groove 3122 and a locking protrusion 3121 adjacent to the locking groove 3122. The locking element 333 is at least partially extended outside the clutch disc body 331 by the elastic force of the elastic member 332, and the elastic member 332 presses the locking element 333 against the locking groove 3122.

[0034] When the power tool 100 is in normal operation, the locking element 333 is engaged in the locking groove 3122, and the first gear 31 and the clutch disc 33 rotate synchronously to link the first gear 31 and the second gear 32. When the cylinder 41 stalls, the locking element 333 compresses the elastic element 332 and moves radially inward along the clutch disc body 331. The locking element 333 slides along the locking groove 3122 and passes over the locking protrusion 3121. The rotation of the first gear 31 and the clutch disc 33 is separated to separate the transmission of the first gear 31 and the second gear 32, so that the first gear 31 rotates freely to prevent the hand from twisting due to stalling and causing injury to the operator.

[0035] In this embodiment, the elastic element 332 is configured as a spring, and the second gear 32 and the third gear 42 are configured as bevel gears.

[0036] In this embodiment, a recessed 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 a meshing length L extending in the first direction, and the second gear 32 and the third gear 42 have a meshing length X extending in the first direction. The projections of the meshing length L and the meshing length X in the first direction at least partially overlap. This reduces the size of the two sets of gears meshing in different directions in the first direction, making the internal structure of the power tool 100 compact, thereby reducing the overall size of the power tool 100 and achieving miniaturization of the power tool 100.

[0037] This invention is not limited to the specific embodiments described above. Those skilled in the art will readily understand that many alternative power tools can be developed without departing from the principles and scope of this invention. The scope of protection of this invention is defined by the claims.

Claims

1. An electric tool, comprising a housing, a motor mounted within the housing, a clutch assembly driven by the motor, and an output assembly driven by the clutch assembly, wherein the motor includes a motor shaft extending along a first direction, the clutch assembly includes a first gear meshing with the motor shaft and a second gear coaxial with and linked to the first gear, and the output assembly includes a cylinder extending perpendicular to the first direction and a third gear sleeved on the cylinder, the second gear meshing with the third gear and driving the cylinder to rotate, and when the cylinder stalls, the first gear and the second gear disengage, characterized in that: The first gear has a recessed first cavity at one end facing the cylinder, and 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, and the second gear and the third gear have a meshing length X extending along the first direction. The projections of the meshing length L and the meshing length X in the first direction at least partially overlap.

2. The power tool according to claim 1, characterized in that: 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.

3. The power tool according to claim 2, characterized in that: The clutch assembly includes a clutch disc, which is non-rotatably fitted onto the connecting portion.

4. The power tool according to claim 3, characterized in that: The first gear has a support portion and a first meshing portion that is vertically connected to the support portion and extends along the first direction. The first meshing portion is connected to the motor shaft. The support portion and the first meshing portion surround a first cavity and a second cavity that is disposed opposite to the first cavity. The second cavity at least partially accommodates the clutch disc.

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

6. The power tool according to claim 5, characterized in that: The inner peripheral wall of the first engaging part has several locking grooves and locking protrusions adjacent to the locking grooves, and the elastic member presses the locking element against the locking groove; When the power tool is operating normally, the locking element is engaged in the locking groove, and the first gear rotates synchronously with the clutch disc to link the first gear and the second gear in rotation. When the cylinder stalls, the locking element compresses the elastic element and moves radially inward along the clutch disc body. The locking element slides along the locking groove and passes over the locking protrusion, causing the first gear to separate from the rotation of the clutch disc, thereby separating the first gear from the second gear transmission.

7. The power tool according to claim 1, characterized in that: The second gear and the third gear are configured as bevel gears.

8. The power tool according to claim 7, characterized in that: The power tool includes an eccentric gear that meshes with the motor shaft.

9. The power tool according to claim 8, characterized in that: 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 mesh on the left and right sides of the motor shaft, respectively.

10. The power tool according to claim 8, characterized in that: The power tool also includes an impact assembly housed within the cylinder, and the eccentric gear includes an eccentric disc, which is connected to the impact assembly to drive the impact assembly to reciprocate within the cylinder.

Images